Article

Reductive dissolution by waste newspaper for enhanced meso-acidophilic bioleaching of copper from low grade chalcopyrite: A new concept of biohydrometallurgy

Authors:
  • Gujarat Biotechnology University
  • College of Engineering & Technology, Bhubaneswar
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Abstract

Dumping of low-grade chalcopyrite encompasses several environmental problems. Despite slow dissolution rate, meso-acidophilic bioleaching is preferred for the extraction of copper from such ores. In the present study, meso-acidophilic bioleaching of a low-grade chalcopyrite in presence of an acid-processed waste newspaper (PWp) is discussed for the first time. The study illustrated a strong catalytic response of PWp with enhanced bio-recovery of copper from acid-conditioned chalcopyrite. A maximum of 99.13% copper recovery (0.36% Cu dissolution/day) was obtained in 6 days of bioleaching in presence of 2 gL- 1 PWp in contrast to only 5.7% copper in its absence. FTIR analysis of bioleached residues revealed similar spectral patterns to the original acid-conditioned ore in presence of PWp, thus indicating less development of passivation layer which was also confirmed through a complementary raman characterization of the bioleached residues. Further, a reaction mechanism (chemistry) was proposed suggesting the possible role of PWp as the electron donor under oxygen limiting conditions which facilitated microbial reduction of Fe (III). The resulting biochemical changes provided an energy source for the bacteria, thus allowing free flow of electrons through the ore surface, thus contributing towards enhanced bioleaching of copper.

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... In recent years, lignocellulosic is attracting considerable critical attention in the bioleaching process. Panda et al. (2015) tried to speed up the chalcopyrite bioleaching process by adding waste newspaper. The Cu leaching extent with 2 g⋅L − 1 waste newspaper was increased by 38% after 6 days. ...
... (1) and (2), and improving the biooxidation kinetics of pyrite. In the presence of RH, the pyrite biooxidation process can be expressed by Eq. (5) (Panda et al., 2015). The generated CO 2 can be used by carbon-fixing microorganisms to promote the respiration of related microorganisms. ...
... Jarosite (Henao and Godoy, 2010) 827 Carbonate (Godočı́ková et al., 2002) 631, 633 Jarosite (Yang et al., 2020) 515 Jarosite (Panda et al., 2015) ...
Article
This work seeks to understand the role of hydrolyzed rice husk in pyrite bio-oxidation. Solution parameters during the bio-oxidation process were monitored, and the bio-oxidation residues were characterized by Scanning Electron Microscopy, Raman Spectroscopy, and Fourier Transform Infrared Spectroscopy. Results showed that rice husk mainly affected pyrite bio-oxidation by promoting microbial reproduction and changing microbial community. It mainly inhibited the reproduction of Sulfobacillus and promoted the reproduction of Leptospirillum. There was a significant positive correlation between pyrite oxidation and the proportion of Leptospirillum. Rice husk had no obvious impact on the adhesion of different microorganisms on the pyrite surface. Quantity and hydrolysis of rice husk are the two factors that affect microbial communities. 1 g·L⁻¹ of fully hydrolyzed rice husk can maximize the pyrite bio-oxidation by about 20% after 14 days. The promoting mechanism of rice husk on pyrite bio-oxidation is summarized based on the results, which provides theoretical support for future industrial applications.
... Though, these catalytic additives significantly enhanced the metals recovery from the chalcopyrite ores, however, these catalysts are often uneconomical and associated with harmful effects on microbial structural communities. The use of Ag + enhances the overall processing cost and the chloride ions create osmotic stress and inhibit bacterial growth while, sonication is generally associated with the degradation of living cells of microbes (Panda et al., 2015). Therefore, an appropriate catalyst, which can control the overall oxidation-reduction reaction during the process, improve the metal recovery rate, and can be scaled up, would significantly improve the metals recovery from the low-grade ores. ...
... The use of indigenous iron-oxidizing bacterial consortia of known nature is more effectual in metals recovery (Sajjad et al., 2018a(Sajjad et al., , 2019b. The use of an appropriate catalytic agent is advantageous for bioleaching like an acid treated newspaper (Panda et al., 2015) and acid-treated rice straw (Yin et al., 2019) that is cost-effective, eco-friendly with enhanced metals extraction. However, it is not only essential to probe the influence of catalytic agents on metals recovery but also on bacterial structural community dynamics in a more controllable way. ...
... However, it is not only essential to probe the influence of catalytic agents on metals recovery but also on bacterial structural community dynamics in a more controllable way. Panda et al. (2015) did not check the influence of catalytic agent on bacterial community structural shifts. While, Yin et al. (2019) probed the influence of catalytic agent on bacterial structural shifts in the middle and at the end of the bioleaching process. ...
Article
Disposing of low-grade ores involves numerous environmental issues. Bioleaching with acidophilic bacteria is the preferred solution to process these ores for metals recovery. In this study, indigenous iron-oxidizing bacteria Acidithiobacillus ferrooxidans, Leptospirillum ferriphilum, and Leptospirillum ferrooxidans were used in consortia supplemented with acid-treated bamboo sawdust (BSD) for copper and zinc recovery. Findings showed the extreme catalytic response of BSD with the best recovery of metals. Maximum of 92.2 ± 4.0% copper (0.35%) and 90.0 ± 5.4% zinc (0.33%) were recovered after 8 days of processing in the presence of 2 g/L BSD. Significant variations were reported in physicochemical parameters during bioleaching in the presence of a different concentration of BSD. Fourier Transform Infrared spectroscopy results of bioleached residues showed significant variations in spectral pattern and maximum variations were reported in 2.0 g/L BSD, which indicates maximum metals dissolutions. The impact of bacterial consortia and BSD on iron speciation of bioleached ores was analyzed by using Mössbauer spectroscopy and clear variations in iron speciation were reported. Furthermore, the bacterial community structure dynamics revealed significant variations in the individual bacterial proportion in each experiment. This finding shows that the dosage concentration of BSD influenced the microenvironment, which effect the bacterial abundance and these variations in the bacterial structural communities were not associated with the initial proportion of bacterial cells inoculated in the bioleaching process. Moreover, the mechanism of chemical reactions was proposed by explaining the possible role of BSD as a reductant under micro-aerophilic conditions that facilitates the bacterial reduction of ferric iron. This type of bioleaching process with indigenous iron-oxidizing bacteria and BSD has significant potential to further upscale the bioleaching process for recalcitrant ore bodies in an environment friendly and cost-effective way.
... The peaks in the bioleached residues at the range 1001-1080 cm À1 ; and 772.84 cm À1 show variations and became narrower as compared to control peaks and are ascribed to the dissolution of some quartz portion existed in higher quantity in the ore body. Comparable bands variation patterns were observed by Prasad et al. (2006); Panda, Biswal et al. (2015). Similarly, variations at the ranges 515-700, 800-818.43, ...
... These results show the bacterial dissolution of the iron and sulfur contents existing in the ore. These findings are supported by the results of Ruan et al. (2001); Ding et al. (2007) and Panda, Biswal et al. (2015). The bands present at 3434.5-3455.2 ...
... The bands present at 3434.5-3455.2 cm À1 could be ascribed to adsorbed water stretching on the ore surface or OH functional group attached to numerous iron oxides mainly goethite (FeOOH) (Panda, Biswal et al. 2015;Prasad et al. 2006;Ruan et al. 2001). Moreover, the mineral of goethite is strongly bonded by hydrogen with n(OH) stretching mode at 3100-3150 cm À1 (Libowitzky and Rossman 1997;Russell and Fraser 1994). ...
Article
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This study aimed to investigate the ability of pure and consortia of indigenous iron-oxidizing bacteria to enhance the dissolution of trace metals from Cu and Zn-bearing ore. Three bacterial strains Acidithiobacillus ferrooxidans strain WG101, Leptospirillum ferriphilum strain WG102, Leptospirillum ferrooxidans strain WG103 isolated from Baiyin copper mine, China were used in this study. The biotechnological potential of these indigenous isolates was evaluated both in pure and in consortia to extract cobalt, chromium, and lead from the copper and zinc bearing ore. The sulfur and iron-oxidizing bacterial isolate Acidithiobacillus ferrooxidans strain WG101 exhibited efficient dissolution compared to sole iron-oxidizing Leptospirillum ferriphilum strain WG102, and Leptospirillum ferrooxidans strain WG103. Initial medium pH, pulp density, and temperature were studied as influential parameters in bioleaching carried out by bacterial consortia. The achieved optimum conditions were; initial pH of 1.5, 10% of pulp density, and temperature 30 C with 68.7 ± 3.9% cobalt, 56.6 ± 3.9% chromium, and 36 ± 3.7% lead recovery. Analytical study of oxidation reduction potential and pH fluctuation were observed during this whole process that shows the metal dissolution efficiency of bacterial consortia. Alterations in spectral bands of processed residues were reported through FTIR analysis compared with control ore sample. M€ ossbauer spec-troscopy analysis showed the influence of bacterial consortia on iron speciation in bioleached samples. The findings confirm that the indigenous acidophilic iron-oxidizing bacterial strains are highly effective in the dissolution of trace elements present in ore samples. This study not only supports the notion that indigenous bacterial strains are highly effectual in metal dissolution but provides the basic vital conditions to upscale the bioleaching technique for metals dissolution. ARTICLE HISTORY
... Depletion of highgrade ore resources due to global rise in human population and industrial development has increased the demands of metals. Over the previous several years, extraction of metals from low-and lean-grade ores using microorganisms has been developed into an effective and growing area in biotechnology (Panda et al. 2015). These microorganisms catalyze the metals recovery by dissolution of metals present in low-grade sulfide minerals through bioleaching technique or dissolve sulfide minerals to unlock the associated metals within refractory ores (biooxidation) such as gold that would be finally extracted through conventional methods (Johnson 2013). ...
... Reduction of high-grade ore resources is not only concern for mining industry but the concurrent increase in low-grade ores leads to numerous environmental issues and Communicated by A. Driessen. occupies additional land area because of higher dump activities (Panda et al. 2015). ...
... Recently, consortia of acidophilic bacteria such as At. ferrooxidans, At. thiooxidans, and Leptospirillum ferrooxidans have shown auspicious results for copper extraction from low-grade ores and a favored consortium for large-scale heap bioleaching process (Panda et al. 2012(Panda et al. , 2015. It is strongly believed that the indigenous microorganisms obtained from the same site would be more efficient to recover metals from the ores as indigenous bacteria are more compatible with the mineralogy of the rocks. ...
Article
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Indigenous iron-oxidizing bacteria were isolated on modified selective 9KFe2+ medium from Baiyin copper mine stope, China. Three distinct acidophilic bacteria were isolated and identified by analyzing the sequences of 16S rRNA gene. Based on published sequences of 16S rRNA gene in the GenBank, a phylogenetic tree was constructed. The sequence of isolate WG101 showed 99% homology with Acidithiobacillus ferrooxidans strain AS2. Isolate WG102 exhibited 98% similarity with Leptospirillum ferriphilum strain YSK. Similarly, isolate WG103 showed 98% similarity with Leptospirillum ferrooxidans strain L15. Furthermore, the biotechnological potential of these isolates in consortia form was evaluated to recover copper and zinc from their ore. Under optimized conditions, 77.68 ± 3.55% of copper and 70.58 ± 3.77% of zinc were dissolved. During the bioleaching process, analytical study of pH and oxidation-reduction potential fluctuations were monitored that reflected efficient activity of the bacterial consortia. The FTIR analysis confirmed the variation in bands after treatment with consortia. The impact of consortia on iron speciation within bioleached ore was analyzed using Mössbauer spectroscopy and clear changes in iron speciation was reported. The use of indigenous bacterial consortia is more efficient compared to pure inoculum. This study provided the basic essential conditions for further upscaling bioleaching application for metal extraction.
... During direct bioleaching bacteria are involved in maintaining high redox potential by constantly oxidizing Fe 2+ to Fe 3+ Since bacteria use Fe 2+ as an energy source to support their growth, their number concurrently increases with the regeneration of Fe 2+ from Fe 3+ maintaining a continuous bioleaching cycle with metal solubilization. ORP increased to > 600 mV in direct systems as a result of biological oxidation of Fe 2+ to Fe 3+ , but in the chemical-control ORP remained below 350 mV [28,[33][34][35][36]. As shown in Fig. 4(b), the profiles of redox potential under the single-step and two-step direct conditions were similar. ...
... A strong band near 1000 cm −1 was assigned to O-H bending. However, the IR absorbance frequencies observed at 3400 cm −1 can be assigned to the loosely bonded or free water molecules adsorbed on the surface or the stretching of OH groups of iron oxides especially goethite (FeOOH) [34,48,49]. ...
... Chalcopyrite (CuFeS 2 ) is the richest copper-bearing mineral, accounting for nearly two-third of the world's copper reserves [1], while it is also extremely recalcitrant to (bio)hydrometallurgical processing [2]. In practice, industrial-scale bioleaching is generally carried out by the use of mesophilic microorganisms like Acidithiobacillus ferrooxidans, Acidithiobacillus thiooxidans, and Leptospirillum ferrooxidans because they are dominant species at normal atmospheric temperatures [3]. ...
... ferrooxidans. When S 0 is biooxidized into sulfate, the solution pH value decreases, as illustrated by Reaction (1). Therefore, the sulfur oxidation rate could be evaluated indirectly by the change of the pH value of the medium. ...
Article
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Chalcopyrite is the richest copper sulfide mineral in the world, but it is also the most resistant to biohydrometallurgical processing. To promote the bioleaching of chalcopyrite, a nonionic surfactant, t-octyl phenoxy polyethoxy ethanol (Triton X-100), was employed in this paper. Action of Triton X-100 in chalcopyrite leaching using Acidithiobacillus ferrooxidans was explored in shake flasks. Results showed that 30 mg·L−1 of Triton X-100 increased the bioleaching yield of copper by 42.21% compared to the process without additive after 24 days. Under the stress of Triton X-100, the bioleaching efficiency of chalcopyrite slightly dropped at an early stage, but remarkably increased afterwards. XRD and XPS analysis of the leach residues demonstrated that potassium jarosite and elemental sulfur resulted in surface leaching passivation. Surfactant Triton X-100 appeared to induce the oxidation of elemental sulfur by bacteria owing to the increase in the sulfur surface hydrophobicity. These results suggest that Triton X-100 itself has no ability to leach chalcopyrite, but under its induction, the bioleaching of chalcopyrite can be enhanced due to the removal of the passivation layer.
... At 27 h, on the day of processing, the copper recovery rate was 100% (Figure 9b) using indigenous Arm. Mixed cultures of acidophiles are typically considered to be more effective than pure cultures for dissolving metals [36,[55][56][57][58], as the consortium has a higher capability to resist copper, zinc, arsenic, and chloride ions, compared to pure cultures. In this study, consortia of bacterial strains were found to be very effective in copper dissolution under optimized conditions. ...
Article
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Bioleaching of Cu from the copper concentrate of Armanis gold-bearing polymetallic ore (Armenia) was investigated. The main objective was revealing high active bacteria and their association, as well as optimizing the bioleaching process with their application to ensure the most efficient recovery of copper from the tested concentrate. To obtain optimal bacterial associations, bottom-up and top-down approaches were used. Bioleaching of copper concentrate was carried out using pure cultures of iron- and sulfur-oxidizing bacteria and their mixed culture, as well as indigenous bacterial consortium. Comparative studies of copper bioleaching by mixed cultures of Acidithiobacillus caldus, Leptospirillum ferriphilum CC, Sulfobacillus thermosulfidooxidans 6, and indigenous consortium Arm of iron-oxidizing bacteria were performed. At the beginning of bioleaching, the amounts of extracted copper by mixed culture and Arm consortium were equal; afterward, between 20–27 days, the Arm indigenous consortium showed significantly higher activity in terms of copper extraction. In parallel, mineralogical and liberation analyses of feed material and bioleaching residues were performed.
... Acid leaching and complexation mechanisms have been considered as part of the bioleaching mechanism in recent years, especially for the dissolution of gold and gangue minerals . In general, based on the metabolic activities of microorganisms, bioleaching allows metal elements to enter the solution in an ionic form, as shown in Fig. 4 (Panda et al., 2015). It has been shown that microorganisms are more efficient in their contact mechanism when they connect to the material surface using extracellular polymers (EPS). ...
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Bioleaching of lithium-ion batteries is a microbially catalyzed process. Under the action of redox, acid leachingand complexation in the presence of microorganisms, the valuable metals in the cathode material enter the liquidphase as ions and are subsequently recovered from the succeeding process. This technique has the advantages ofbeing inexpensive, environmentally friendly and having simple needs. However, it is still in development and hasnot yet commercialized. In this paper, the technology is fully discussed based on numerous excellent studies. Thecontents include commonly utilized microorganisms, bioleaching mechanism, microbial stress response andmetabolic activation, enhancement strategies, leaching characteristics and interfacial phenomena, processevaluation, and a critical discussion of recent research breakthroughs. They give readers with comprehensive andin-depth understanding on the bioleaching of lithium-ion batteries and help to improve the technology’sindustrialization. Researchers can make new explorations from the potential research directions and methodspresented in this work to make biotechnology better serve resource recovery and social development.
... Este tipo de tecnología ha captado considerablemente el interés debido a los beneficios económicos y por ser ecológicamente amigable. Es así como se aplica principalmente en la recuperación de cobre y oro, siendo responsable del 20 -25% de la producción mundial de cobre (Watling 2006;Panda et al. 2015). ...
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La biolixiviación, usando consorcios microbianos, es considera una alternativa ecoeficiente y de bajo costo para la recuperación de metales a partir de minerales de baja ley. En este estudio, se realizó la caracterización fisiológica y molecular de consorcios microbianos psicrotolerantes lixiviantes (CMPL), aislados de drenajes ácidos de minas de cuatro localidades mineras de las provincias de Pasco y Huarochirí, Perú, ubicados sobre los 4200 m de altitud. Se aislaron seis consorcios adaptados a medio 9K con ion ferroso y medio basal 9K con CuS al 0.5% p/v a 15 °C. Se evidenció la liberación de cobre en todos los consorcios. El CMPL con mejor crecimiento, presentó una recuperación de cobre de 12.47% en 30 días de evaluación. Los análisis de la secuenciación del gen ARNr 16S de la comunidad bacteriana, mostraron que los CMPL están dominados por el género Acidithiobacillus, seguido de Acidiphilium. En conclusión, se obtuvieron consorcios que pueden ser aplicados en biolixiviación de cobre en la minería altoandina.
... ferrooxidans) and Acidithiobacillus thiooxidans (At. thiooxidans), play a significant role in metal extraction from various ores and minerals (Panda et al., 2015). Microorganisms responsible for bioleaching meet the energy requirements essential for their growth by oxidation of ferrous iron and reduced sulfur compounds under low pH conditions. ...
... Compared to traditional hydrometallurgy and pyro-metallurgy, which use many chemicals and produce much environmental pollution, bioleaching provides some advantages (Zeng et al. 2013). For example, some effective commercial bioleaching plants are currently in operation at the Morenci mine in the USA, which has a capacity of up to 230,000 tonnes per year (Panda et al. 2015). Additionally, it provides a broad overview of the bioleaching process and mechanism, opening the door to creating better and more effective industrial bioleaching operations. ...
Chapter
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In the leap of electronic vehicle era, an enormous amount of electronic trash is produced due to the growing usage of electrical and electronic devices (e-waste), which is one of the ever-increasing urgent issues, especially in developing nations. Many e-wastes are buried, burned outdoors, or discharged into surface water bodies in these nations since there is no infrastructure to handle them properly. Many developing countries currently use inefficient and highly polluting recycling techniques. Several harmful compounds of e-wastes are detrimental to the environment and endanger human health if disposal processes are not carefully handled. Design for environment cleaner production, extended producer responsibility, standards and labelling, product stewardship, recycling, and remanufacturing are some strategies many nations take to cope with the e-waste stream. This chapter discusses an overview of traditional (landfills and dumps, recycling, thermo-chemical treatment, pyrometallurgical treatment, bio-sorption, bioleaching, bioremediation methods, phytoremediation) and modern techniques (life cycle assessment (LCA), material flow analysis (MFA), and multi-criteria analysis (MCA)) in e-waste management that contribute to the eco-friendly, sustainable management of e-waste.
... However, bioleaching has been proposed as a low-cost and environmentally friendly, alternative method for Mn metal extraction from the low grade manganese ores. Micro-organisms capable of metal recovery from those low-grade manganese ores have been well investigated and many such bacteria have been reported (e.g., [19,90,91]. Furthermore, in laboratory experiments mixed culture bioleaching has been found to be a more rapid and extensive process than that with pure cultures [19]. ...
Article
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In this study, we have compiled new and existing mineralogical and geochemical data on Fe-Mn mineralization from the Aegean region [Attica (Grammatiko, Legrena, and Varnavas), Evia and Milos islands], aiming to provide new insights on the genesis of Fe-Mn mineralization in that region and its potential environmental implications. A common feature of those deposits is the relatively low Cr, Co, V, Ni, Mo, and Cd content, whereas Ba, As, W, Cu, Pb, and Zn show remarkably variable values. The Mn-Fe deposits from Milos exhibit the highest tungsten content, while a positive trend between MnO and W, combined with a negative trend between MnO and Fe2O3 suggests the preference of W to Mn-minerals. The occurrence of bacterio-morphic Fe-Mn-oxides/hydroxides within Mn-Fe mineralizations in the studied region, indicates the important role of micro-organisms into redox reactions. Moreover, the presence of micro-organisms in the Fe-Mn-deposits, reflecting the presence of organic matter confirms a shallow marine environment for their deposition. A salient feature of the Varnavas and Milos Mn-Fe ores is the presence of sodium chloride coated fossilized micro-organisms, suggesting development from a solution containing relatively high Na and Cl concentrations. Furthermore, from an environmental point of view, consideration is given to the bioavailability of elements such as As, Pb, and W, related to the above-mentioned mineralizations. The high bio-accumulation factor for W (Wplant/Wsoil × 100) recorded in the Neogene sedimentary basins of Attica, related to the Grammatiko Fe-Mn mineralization, reflects the high W mobility under alkaline conditions and the potential environmental impact of similar deposits with elevated W content.
... The high demand for copper will continue in the coming years as copper-based products are increasingly manufactured; it is expected that the world's major copper-producing countries will produce billions of tons of copper tailings in the next few years (Onuaguluchi and Eren, 2016). Chalcopyrite, as the most abundant copper-bearing mineral on earth (Panda et al., 2015), is the main source of extracting copper and producing copper tailings. The mining and processing of low-grade chalcopyrite would produce a large quantity of tailings accumulated in the mining area (Chopard et al., 2017). ...
Article
Humic acid has the advantages of wide source, easy availability and environmental friendliness, which may be a good choice for inhibiting chalcopyrite biooxidation and alleviating copper pollution. However, there are few researches on the inhibitory effect and mechanism of humic acid on the biooxidation of chalcopyrite. In order to fill this knowledge gap, this study proposed and validated a novel method for inhibiting chalcopyrite biooxidation by means of humic acid. The results showed that the biooxidation of chalcopyrite could be effectively inhibited by humic acid, which consequently decreased the release of copper ions. Humic acid with a concentration of 120 ppm had the best inhibitory effect, which reduced the biooxidation efficiency of chalcopyrite from 40.7 ± 0.5 % to 29.3 ± 0.8 %. This in turn suggested that humic acid could effectively suppress the pollution of copper under these conditions. The analysis results of solution parameters, mineral surface morphology, mineral phases and element composition showed that humic acid inhibited the growth of Acidithiobacillus ferrooxidans, promoted the formation of jarosite and intensified the passivation of chalcopyrite, which effectively hindered the biooxidation of chalcopyrite, and would help to alleviate the pollution of copper.
... From day 1 to day 70, the pH of the leachate of two columns changed drastically, and the concentrations of copper ion, ferrous iron, and TFe were low; the pH increment after each pH adjustment and the pH in both columns maintained below 2.5 from day 71 to day 136, it can be found the concentrations of copper ion, ferrous iron, and TFe increased. Low-grade chalcopyrite is often accompanied by a large amount of alkaline gangue, which affected the iron ions and H + in the leachate during the dissolution process of chalcopyrite (Panda et al. 2015b;Mwase et al. 2012). Low pH of leachate was beneficial a gradual increase of copper ion accumulation (Fig. 2) (Muddanna and Baral 2021;Wang et al. 2018c). ...
Article
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Low-grade ores, tailings, and solid wastes contain small amounts of valuable heavy metals. Improper disposal of these substances results in the waste of resources and contamination of soil or groundwater. Accordingly, the treatment and recycling of low-grade ores, tailings, and solid wastes attracted much attention recently. Bioelectrochemical system, an innovative technology for the removal and recovery of heavy metals, has been further developed and applied in recent years. In the current study, the low-grade chalcopyrite was bioleached with the assistance of microbial fuel cells. Copper extraction along with electricity generation from the low-grade chalcopyrite was achieved in the column bioleaching process assisted by MFCs. Results showed that after 197 days bioleaching of low-grade chalcopyrite, 423.9 mg copper was extracted from 200 g low-grade chalcopyrite and the average coulomb production reached 1.75 C/d. The introduction of MFCs into bioleaching processes promoted the copper extraction efficiency by 2.7 times (3.62% vs. 1.33%), mainly via promoting ferrous oxidation, reducing ORP, and stimulating bacterial growth. This work provides a feasible method for the treatment and recycling of low-grade ores, tailings, and solid wastes. But balancing energy consumption of aeration and circulation frequency and chemical consumption of acid to improve the copper extraction efficiency need further investigation.
... Being the most abundant copper sulfide mineral and main copper resource [14,15], chalcopyrite has attracted extensive attention in copper extraction. So far, the main process for extracting copper from chalcopyrite is pyrometallurgy, although hydrometallurgy is sometimes used [16]. ...
Article
Even though biodissolution of chalcopyrite is considered to be one of the key contributors in the formation of acid mine drainage (AMD), there are few studies to control AMD by inhibiting chalcopyrite biodissolution. Therefore, a novel method of using hematite to inhibit chalcopyrite biodissolution was proposed and verified. The results indicated that chalcopyrite biodissolution could be significantly inhibited by hematite, which consequently decreased the formation of AMD. In the presence of hematite, the final biodissolution rate of chalcopyrite decreased from 57.9% to 44.4% at 20 day. This in turn suggested that the formation of AMD was effectively suppressed under such condition. According to the biodissolution results, mineral composition and morphology analyses, and electrochemical analysis, it was shown that hematite promoted the formation and accumulation of passivation substances (jarosite and Cu2−xS) on chalcopyrite surface, thus inhibiting the biodissolution of chalcopyrite and limiting the formation of AMD.
... For the surface properties study, Raman spectroscopy (BRUKER-SENTERRA, Liège, Germany) was done. The Raman spectrum for the original ore had broad bands with sharp peaks at approximately 340 and approximately 380 cm −1 that can be assigned to pyrite (Panda et al. 2015). The peak at approximately 480 is ascribed to anorthite, which is confirmed by XRD. ...
Article
Leaching of zinc from sulfide minerals is a subject of considerable interest over the last few years. Ferric solutions were commonly reported to leach base metals sulfide concentrates. The current study investigates the potential of biological ferric solutions for Zn and Pb extractions from a sphalerite concentrate at 65°C. Comparative leaching experiments with ferric sulfate and ferric chloride are also performed. Actually, biological ferric ions have resulted from pyrite bio-oxidation. The aim of this work is to introduce a potential application of this metabolite as a mineral oxidizing agent to recover zinc from the sphalerite concentrate. To produce a biogenic reagent with the highest ferric, the bio-oxidation process is optimized by investigating the effects of different factors including pH, pulp density, and inoculum percent. At the optimum conditions, a metabolite with 7.87 g/L of ferric ions and a pH = 0.98 is produced. The results indicate that pyrite bio-oxidation includes three phases: chemical dissolution, lag phase, and biological dissolution. The scanning electron microscope (SEM) images showed that a layer of crystals was present on the surface of pyrite. Based on energy-dispersive X-ray spectroscopy (EDS) and Raman spectroscopy, this layer is related to the presence of potassium jarosite. The metabolite was then used for ZnS direct leaching and results were compared with sulfide and chloride leaching. The final zinc recoveries with biological ferric ions, ferric sulfate, and ferric chloride were 78.0%, 88.9%, and 85.4%, respectively.
... As shown in Fig. 4a, the pH in both columns appeared an increase after each pH adjustment, which was attributed to the acid consumption for the dissolution of alkaline gangue and chalcopyrite (Panda et al., 2015b). It should be noted that the pH increment after each pH adjustment gradually narrowed with time, and the pH in both columns maintained below 2.5 from day 71 to day 136. ...
Preprint
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Low-grade ores, tailings and solid wastes contain small amounts of valuable heavy metals. Improper disposal of these results in the waste of resources and contamination of soil or groundwater. Accordingly, the treatment and recycling of low-grade ores, tailings and solid wastes attracted much attention recently. Bioelectrochemical system, an innovative technology for the removal and recovery of heavy metals, has been further developed and applied in recent years. In current study, the low-grade chalcopyrite was bioleached with the assistance of microbial fuel cells. Copper extraction along with electricity generation from the low-grade chalcopyrite were achieved in the column bioleaching process assisted by MFCs. Results showed that after 197 days bioleaching of low-grade chalcopyrite, 423.9 mg copper was extracted from 200 g low-grade chalcopyrite and the average coulomb production reached 1.75 C/d. The introduction of MFCs into bioleaching processes promoted the copper extraction efficiency by 2.7 times (3.62% vs. 1.33%), mainly via promoting ferrous oxidation, reducing ORP and stimulating bacterial growth. This work provides a feasible method for the treatment and recycling of low-grade ores, tailings and solid wastes. But balancing energy consumption of aeration and circulation frequency and chemicals consumption of acid to improve the copper extraction efficiency need further investigation.
... The N -O bond in the -C=N -OH group often appears at the range of 1125-1100 cm −1, and also, the elemental sulfur bands emerge within 1000-1200 cm −1 . The bands at 1194 and 1187 cm −1 asymmetric stretching vibrations of -SO 4 2- (Panda et al. 2015;Varotsis et al. 2014). The vibration of aromatic groups associated with LIX 984N and Acorga M5640 appears within 1630 and 1450 cm −1 (Li et al. 2019). ...
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Due to entrainment or dissolution, organic extractants can contaminate aqueous raffinate during the solvent extraction (SX) process. This study aims to evaluate the effect of conventional SX reagents on the bio-oxidation and metabolism of industrial bacteria. Evaluating the effect of LIX 984N, Chemorex CP 150, D2EHPA, and Acorga M5640 at three concentrations on mesophiles and moderate thermophiles revealed that all extractants reduced the bacterial efficiency at different extents. It was observed that organic phases at 0.02% v/v resulted in a decrement of ferrous iron bio-oxidation rate and a negligible decrease in the bacterial population. At high dosages like 2% v/v, bio-oxidation and bacterial reproduction were utterly disrupted. The oxime-based extractants had a more significant effect on bacteria due to their lower stability and production of toxic substances by hydrolysis. Organic phases more impacted moderate thermophiles at a higher temperature compared to mesophiles. The analysis of Kendall tau-b revealed a strong inter-correlation between the concentration of organic phase and bio-oxidation parameters such as pH, ORP, bacterial population, bio-oxidation rate, and iron precipitation.
... The addition of 0.66 g/L sodium chloride can reduce the elemental sulfur content on the mineral surface from 26% to 3% (Chang- . Recently, some authors found that lignocellulose can reduce the amount of jarosite (Panda et al. 2015b;Yin et al. 2019), which gives us some ideas. It may be beneficial to lay a thin layer of plant stalks at every certain height (e.g. 1 m). ...
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Heap bioleaching is a microbial technology that catalyzes the decomposition of ore without grinding. The crushed ore is stacked on the liner, and the microbial solution flows through the heap from top to bottom. Under the oxidation action of Fe³⁺, valuable metals in sulfide enter the liquid phase as ions, which are then recovered from the subsequent process. The main function of microorganisms are the regeneration of Fe³⁺. This technology has the advantages of low cost, environment friendliness, simple requirements, and suitability for the treatment of low-grade ore. It has been applied to industrial production. However, the technology is still evolving because there are still many problems that are not well explained, such as synergistic effect between microorganisms, the role of extracellular polymeric substances, passivation phenomenon, galvanic interaction between minerals, mode of ore treatment and heap running, the impact of the natural environment, reasonable disposal of tailings, etc. This paper adequately discusses these aspects based on plentiful excellent researches, including the latest ideas, which can provide a comprehensive and in-depth knowledge of heap bioleaching for the readers. Besides, commercial process data, effective improvement measures, environmental protection ways, laboratory research, and optimization methods were reviewed. Based on the comparative analysis of these knowledges, the recommended technical parameters and the remaining challenges are displayed, which can guide a new commercial or pilot-scale heap. Researchers can make new explorations from the potential research directions and methods proposed in this paper, so that heap bioleaching technology can better serve social development.
... An experimental study was conducted for bioleaching of low-grade chalcopyrite using a mixed culture of meso-acidophilic microorganisms in the presence of acidprocessed waste newspaper. This study, for the first time, reported that the presence of acidprocessed waste newspaper enhanced the bio-recovery of copper up to a maximum of 99.13% [26]. Some experimental studies also described that the effect of ultrasound pretreatment on nickel leaching using A.niger 95% nickel could be leached along with 12.5% of iron from lateritic ore [27]. ...
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Bioleaching is an environmentally safe as well as economically feasible alternative to the conventional process of metal extraction from low-grade ores. It involves the recovery of metals through microbial oxidation of metallic and/or sulfuric compounds. Wide varieties of acidophilic microbes present in the mining sites, which are necessary to decrease the pH, eventually contribute to the biomining efficiency. Ongoing development and recent advanced techniques will ensure that the implementation of genetic engineering might improve the extraction rate within less time period. The use of OMIC (genomics, proteomics, metabolomics, etc.) techniques in bioleaching is gaining interest worldwide. In the last decade, a number of studies have been carried out for the determination of bioleaching diversity, development of conceptual and functional metabolic models, analysis of microbe-mineral interaction, etc. by using various OMIC technologies. These technologies are used to improve the understanding of various microbial activities during the bioleaching process, which helps in the development of industrial-scale bioleaching process.
... As the dissolution of ores and the oxidation of iron by A. ferrooxidans consumes acid, the addition of elemental sulfur improved nickel recovery from nickel concentrate and reduced the need for sulfuric acid supplementation (Salo-Zieman, Kinnunen, & Puhakka, 2006). In another approach, acid-processed waste newspaper was used as an additive to improve the recovery of copper from chalcopyrite with a mixed consortium through a reductive dissolution mechanism (Panda et al., 2015). These studies demonstrate how optimization of the chemical milieu can provide opportunities for low-cost enhancements to bioleaching processes. ...
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Acidithiobacillus ferrooxidans cells can oxidize iron and sulfur and are key members of the microbial biomining communities that are exploited in the large‐scale bioleaching of metal sulfide ores. Some minerals are recalcitrant to bioleaching due to the presence of other inhibitory materials in the ore bodies. Additives are intentionally included in processed metals to reduce environmental impacts and microbially influenced corrosion. We have previously reported a new aerobic corrosion mechanism where A. ferrooxidans cells combined with pyrite and chloride can oxidize low‐grade stainless steel (SS304) with a thiosulfate‐mediated mechanism. Here we explore process conditions and genetic engineering of the cells that enable corrosion of a higher grade steel (SS316). The addition of elemental sulfur and an increase in the cell loading resulted in a 74% increase in the corrosion of SS316 as compared to the initial sulfur‐ and cell‐free control experiments containing only pyrite. The overexpression of the endogenous rus gene, which is involved in the cellular iron oxidation pathway, led to a further 85% increase in the corrosion of the steel in addition to the improvements made by changes to the process conditions. Thus, the modification of the culturing conditions and the use of rus‐overexpressing cells led to a more than threefold increase in the corrosion of SS316 stainless steel, such that 15% of the metal coupons was dissolved in just 2 weeks. This study demonstrates how the engineering of cells and the optimization of their cultivation conditions can be used to discover conditions that lead to the corrosion of a complex metal target.
... Therefore, research on the generation of AMD due to mining activities has primarily focused on the oxidation/dissolution of pyrite, while research on AMD generation caused by chalcopyrite oxidation/dissolution has not been performed. Chalcopyrite is the most abundant copper-containing sulfide mineral in the lithosphere and the main mineral source for copper extraction (Panda et al., 2015). However, chalcopyrite mining generates a large amount of mineral waste that is stored on the surface of the mine site (Chopard et al., 2017). ...
... Copper is released into environment by industrial and agricultural activities such as mining, metallurgy, sewage irrigation, and fertilization (Araújo et al., 2019). Chalcopyrite is the most abundant copper sulfide mineral in the word (Panda et al., 2015), which is an important source of copper release into the environment. A large amount of mineral waste produced during the chalcopyrite mining is stored on the surface of the mining area (Chopard et al., 2017). ...
... Chalcopyrite is also an important cause of AMD because of its wide distribution and large demand for mining. Chalcopyrite is the most abundant copper sulphide mineral on the earth, and is the primary mineral source for copper extraction (Panda et al., 2015). However, chalcopyrite mining generates large amounts of mineral wastes, most of which are stored on the surface of mine sites (Chopard et al., 2017). ...
... The pH of the bioleaching solution showed an initial increase followed by a slight fluctuation (pH2.8-3.3). The dissolution of alkaline gangue and chalcopyrite in the initial stage was an acid-consuming process (Panda et al., 2015b), which led to this initial increase of pH. The pulp density (w/v) in current study (68% in columns 1#−2# and 120% in columns 3#−4#) was much higher than that in other reports Ma et al., 2018). ...
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A proof-of-concept of copper sulfide mineral bioleaching assisted by microbial fuel cells (MFCs) was demonstrated in current study. Simultaneous copper extraction and electricity generation were obtained in this bioleaching process, providing a novel approach for copper sulfide mineral bioleaching. Compared with bioleaching of a mixture of chalcopyrite concentrate and porphyry molybdenite, bioleaching of chalcopyrite concentrate achieved higher coulomb production but lower copper extraction concentration. After 320 days bioleaching of chalcopyrite concentrate, the copper ion concentration in bioleaching solution was 244.2 mg/L and the average coulomb production was 4.4 ± 2.2C/d. The introduction of MFCs into bioleaching processes promoted copper extraction, mainly via the decrease of pH deriving from the anodic sulfide/sulfur oxidation.
... Bioleaching of metals is carried out by a largely diverse group of microorganisms, mainly including three groups of microorganisms, namely (i) chemolithotrophic prokaryotes, (ii) heterotrophic bacteria and (iii) fungi [47]. In nature, a large variety of chemolithotrophic and organotrophic microorganisms are involved in bioleaching of ores [48] (Panda et al. [189]). Current state-of-the-art research on metal recovery from WEEE via biotechnology involves both autotrophic (i.e. ...
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Critical raw materials (CRMs) are essential in the development of novel high-tech applications. They are essential in sustainable materials and green technologies, including renewable energy, emissionfree electric vehicles and energy-efficient lighting. However, the sustainable supply of CRMs is a major concern. Recycling end-of-life devices is an integral element of the CRMs supply policy of many countries. Waste electrical and electronic equipment (WEEE) is an important secondary source of CRMs. Currently, pyrometallurgical processes are used to recycle metals from WEEE. These processes are deemed imperfect, energy-intensive and non-selective towards CRMs. Biotechnologies are a promising alternative to the current industrial best available technologies (BAT). In this review, we present the current frontiers in CRMs recovery from WEEE using biotechnology, the biochemical fundamentals of these bio-based technologies and discuss recent research and development (R&D) activities. These technologies encompass biologically induced leaching (bioleaching) from various matrices,biomass-induced sorption (biosorption), and bioelectrochemical systems (BES).
... One of the best examples of indirect bioleaching process by A. ferrooxidans is the extraction of copper from chalcopyrite. According to Eq. 10, the indirect bioleaching process causes the monovalent copper (Cu 1+ ) which is not water soluble convert to divalent copper (Cu 2+ ) which is soluble in water (Panda et al. 2015a(Panda et al. , 2015b. ...
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Bio-hydrometallurgical applications have been receiving more attention globally for processing of several metal bearing wastes. Compared to the conventional methods, bioleaching has proved to be a more effective way in treating low-grade ores, due to its economic and ecofriendly advantages. Developments in bioleaching enables this technique to be utilized as an alternative process for extraction of base metals from complex ores (copper, gold etc.) or even concentrates, consequently solving several environmental issues. A variety of parameters can influence the bioleaching efficiency such as physicochemical and microbiological factors, properties of the minerals and processing conditions. Certain organic and inorganic reagents or additives used during the process such as flotation and SX reagents, Ag+, Fe2+, Fe3+, Cu2+, Mg2+, Ni2+, silica, pyrite, activated carbon etc., affect the microorganisms activity and their efficiency for metal leaching. More precise investigation on the effect such materials can provide insights and hence studies have been directed to understand such aspects. Owing to their importance, the present review discusses the influence of certain organic-inorganic reagents and other materials or additives on the growth, oxidation activity and bioleaching efficiency of acidophiles on metal dissolution.
... The final pH of the growth medium was maintained at1.8. Adaptation is considered as a unique biotechnological feature of acidophiles that improves their ability to leach metal values from ores or industrial wastes (desulphurization in this case) (Panda et al., 2015a). Following complete iron oxidation, the active culture was adapted to 2% (w/v) of lignite sample in the same growth medium and the coal adapted culture was further used for biodesulphurization experiments. ...
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Coal has been serving as a profuse source of energy since centuries and several attempts are being made to reduce sulphur emission levels from coal. Recently, pretreatment techniques such as ultrasonication and utilization of surfactants as additives have surfaced aiming at improving the biodesulphurization of coal. In the present study, biodesulphurization of Turkish lignite was studied for the first time using Leptospirillum ferriphilum. Attempts have been made to study the biodesulphurization aspects of the lignite sample where the effect of Fe²⁺ iron, surfactant Span 80 and ultrasonication were studied under shake flask conditions. The study indicated Fe²⁺ to be an essential component in the growth media for improving biodesulphurization performance (with 56.2% total sulphur removal). Span 80 (0.05% v/v) marginally enhanced the biodesulphurization of the lignite sample (nearly 61% of total sulphur removal). The carbon content in the lignite sample increased following biodesulphurization. Ultrasonication of the lignite sample, on the other hand, did not yield significant sulphur removal when compared to the effect of Span 80. About 57.6% of total sulphur could be removed from the sample when ultrasonicated for 60 min. Mineralogical characterization along with thermal analysis of the samples pre and post biodesulphurization provided more information on different phases present in coal and the effect of microbial treatment on them.
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The heavy metal contamination in river and lake sediments endangers aquatic ecosystems. Herein, the feasibility of applying different exogenous mesophile consortiums in bioleaching multiple heavy metal-contaminated sediments from Xiangjiang River was investigated, and a comprehensive functional gene array (GeoChip 5.0) was used to analyze the functional gene expression to reveal the intrinsic association between metal solubilization efficiency and consortium structure. Among four consortiums, the Acidithiobacillus thiooxidans and Leptospirillum ferrooxidans consortium had the highest solubilization efficiencies of Cu, Pb, Zn, and Cd after 15 days, reaching 50.33, 29.93, 47.49, and 79.65%, while Cu, Pb, and Hg had the highest solubilization efficiencies after 30 days, reaching 63.67, 45.33, and 52.07%. Geochip analysis revealed that 31,346 genes involved in different biogeochemical processes had been detected, and the systems of 15 days had lower proportions of unique genes than those of 30 days. Samples from the same stage had more genes overlapping with each other than those from different stages. Plentiful metal-resistant and organic remediation genes were also detected, which means the metal detoxification and organic pollutant degradation had happened with the bioleaching process. The Mantel test revealed that Pb, Zn, As, Cd, and Hg solubilized from sediment influenced the structure of expressed microbial functional genes during bioleaching. This work employed GeoChip to demonstrate the intrinsic association between functional gene expression of mesophile consortiums and the bioleaching efficiency of heavy metal-contaminated sediment, and it provides a good reference for future microbial consortium design and remediation of river and lake sediments.
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Abstract Various anthropogenic activities and natural sources contribute to the presence of radioactive materials in the environment, posing a serious threat to phytotoxicity. Contamination of soil and water by radioactive isotopes degrades the environmental quality and biodiversity. They persist in soils for a considerable amount of time and disturb the fauna and flora of any affected area. Hence, their removal from the contaminated medium is inevitable to prevent their entry into the food chain and the organisms at higher levels of the food chain. Physicochemical methods for radioactive element remediation are effective; however, they are not eco-friendly, can be expensive and impractical for large-scale remediation. Contrastingly, different bioremediation approaches, such as phytoremediation using appropriate plant species for removing the radionuclides from the polluted sites, and microbe-based remediation, represent promising alternatives for cleanup. In this review, sources of radionuclides in soil as well as their hazardous impacts on plant and human health, are discussed. Moreover, various conventional physicochemical approaches used for remediation discussed in detail. Similarly, the effectiveness and superiority of various bioremediation approaches, such as phytoremediation and microbe-based remediation, over traditional approaches have been explained in detail. In the end, future perspectives related to enhancing the efficiency of the phytoremediation process have been elaborated.
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In the leap of electronic vehicle era, an enormous amount of electronic trash is produced due to the growing usage of electrical and electronic devices (e-waste), which is one of the ever-increasing urgent issues, especially in developing nations. Many e-wastes are buried, burned outdoors, or discharged into surface water bodies in these nations since there is no infrastructure to handle them properly. Many developing countries currently use inefficient and highly polluting recycling techniques. Several harmful compounds of e-wastes are detrimental to the environment and endanger human health if disposal processes are not carefully handled. Design for environment cleaner production, extended producer responsibility, standards and labelling, product stewardship, recycling, and remanufacturing are some strategies many nations take to cope with the e-waste stream. This chapter discusses an overview of traditional (landfills and dumps, recycling, thermo-chemical treatment, pyrometallurgical treatment, bio-sorption, bioleaching, bioremediation methods, phytoremediation) and modern techniques (life cycle assessment (LCA), material flow analysis (MFA), and multi-criteria analysis (MCA)) in e-waste management that contribute to the eco-friendly, sustainable management of e-waste.
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The main measure to reduce energy losses is the usage of insulating materials. When the temperature exceeds 500 °C, silicate and ceramic products are most commonly used. In this work, high-crystallinity 1.13 nm tobermorite and xonotlite were hydrothermally synthesized from lime and Ca–Si sedimentary rock, opoka. By XRD, DSC, TG and dilatometry methods, it has been shown that 1.13 nm tobermorite becomes the predominant compound in stirred suspensions at 200 °C after 4 h of synthesis in the mixture with a molar ratio CaO/SiO2 = 0.83. It is suitable for the production of insulating products with good physical–mechanical properties (average density < 200 kg·m−1, compressive strength ~0.9 MPa) but has a limited operating temperature (up to 700 °C). Sufficiently pure xonotlite should be used to obtain materials with a higher operating temperature. Even small amounts of semi-amorphous C–S–H(I) significantly increase its linear shrinkage during firing. It has also been observed that an increase in the strength values of the samples correlated well with the increase in the size of xonotlite crystallites. The optimal technological parameters are as follows: molar ratio of mixture CaO/SiO2 = 1.2; water/solid ratio W/S = 20.0; duration of hydrothermal synthesis at 220 °C—8 h, duration of autoclaving at 220 °C—4 h. The average density of the samples was ~180 kg·m−1, the operating temperature was at least 1000 °C, and the compressive strengths exceeded 1.5 MPa.
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Effects of residues produced by agricultural wastes fermentation (AWF) on low grade copper sulfide ores bioleaching, copper recovery, and microbial community were investigated. The results indicated that adding appropriate bulk of AWF made contributions to low grade copper sulfide ores bioleaching, which may be mainly realized through reducing the passivation layer formed by Fe3+ hydrolysis. Improved copper recovery (78.35%) and bacteria concentration (9.56 × 107 cells·mL−1) were yielded in the presence of 5 g·L−1 AWF. The result of 16S rDNA analysis demonstrated that microbial community was differentiated by adding AWF. Bacteria proportion, such as Acidithiobacillus ferrooxidans, Moraxella osloensis, and Lactobacillus acetotolerans changed distinctly. Great difference between samples was showed according to beta diversity index, and the maximum value reached 0.375. Acidithiobacillus ferrooxidans accounted for the highest proportion throughout the bioleaching process, and that of sample in the presence of 5 g·L−1 AWF reached 28.63%. The results should show reference to application of agricultural wastes and low grade copper sulfide ores.
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As the world’s second largest economy experiencing rapid economic growth, China has a huge demand for metals and energy. In recent years, China ranks first, among all the countries in the world, in the production and consumption of several metals such as copper, gold, and rare earth elements. Bioleaching, which is an approach for mining low grade and refractory ores, has been applied in industrial production, and bioleaching has made great contributions to the development of the Chinese mining industry. The exploration and application of bioleaching in China are reviewed in this study. Production and consumption trends of several metals in China over the past decade are reviewed. Technological processes at key bioleaching operations in China, such as at the Zijinshan Copper Mine and Mianhuakeng Uranium Mine, are presented. Also, the current challenges faced by bioleaching operations in China are introduced. Moreover, prospects such as efficiency improvement and environmental protection are proposed based on the current situation in the Chinese bioleaching industry.
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Owing to industrial evolution, a huge mass of toxic metals, including Co, Cu, Cr, Mn, Ni, Pb, and Zn, and metalloids, such as As and Sb, has inevitably been released into the natural environment and accumulated in soils or sediments. Along with modern industrialization, many mineral mines have been explored and exploited to provide materials for industries. Mining industries also generate a vast amount of waste, such as mine tailings, which contain a high concentration of toxic metals and metalloids. Due to the low economic status, a majority of mine tailings are simply disposed into the surrounding environments, without any treatment. The mobilization and migration of toxic metals and metalloids from soils, sediments, and mining wastes to water systems via natural weathering processes put both the ecological system and human health at high risk. Considering both economic and environmental aspects, bioleaching is a preferable option for removing the toxic metals and metalloids because of its low cost and environmental safety. This chapter reviews the recent approaches of bioleaching for removing toxic metals and metalloids from soils, sediments, and mining wastes. The comparison between bioleaching and chemical leaching of various waste sources is also discussed in terms of efficiency and environmental safety. Additionally, the advanced perspectives of bioleaching for environmental remediation with consideration of other influencing factors are reviewed for future studies and applications.
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Tailings used as backfilling material in the presence of mixed bacteria are discussed, and the relationship between mixed bacteria and compressive strength, size variation, water-holding capacity is analyzed in this study. The results illustrate a strong improving response of mixed bacteria with enhanced compressive strength, small size variation and low water-holding capacity of cemented tailings backfill (CTB) specimens. The binder dosage and mixed bacteria proportion have great influence on CTB specimens, which indicate that with the increase of mixed bacteria proportion and binder dosage, compressive strength increased obviously. The maximum compressive strength (4.01 MPa) is obtained in the presence of 100.00% mixed bacteria in contrast to only 2.79 MPa in its absence. Samples added high mixed bacteria proportion yield low water-holding capacity and small size variation. 16 S rDNA analysis illustrates that bacteria community is influenced significantly during experiment. Further, possible reaction mechanism is proposed suggesting the possible role of mixed bacteria as promoter to form precipitation (KFe3(SO4)2(OH)6, (NH4)Fe3(SO4)2(OH)6 and (KH3O)4Fe3(SO4)2(OH)6), which reduces tiny cracks in CTB specimens. The technique of using mixed bacteria to reduce binder consumption in this study shows economic benefits to some extent.
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Zinc bioleaching from sphalerite associated with pyrite ore using Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidant was studied. The ore containing 3.4 wt% zinc and in some experiments its combination with sphalerite concentrate was prepared. The effect of culture media, pH, Fe2+ iron concentration, and the addition of different materials including shredded newspaper, starch, and sugar as a catalyst on the zinc bioleaching were evaluated. It was found that 9 K media, pH of 1.8, and 10 g L−1 Fe2+ iron concentration were optimum conditions. The catalysts acted as an electron acceptor for Fe3+ iron reduction. The amount of zinc bioleaching was obtained 88% for the ore and 95% for the second sample at the optimum pH of 1.8 in 18 days. The addition of starch and shredded newspaper increased the bioleaching rate of zinc. Also, the bioleaching time was decreased from 18 days to 10 and 13 days in the presence of shredded newspaper and starch, respectively.
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Bioleaching is regarded as an essential technology to treat low grade minerals, with the distinctive superiorities of lower-cost and environment-friendly compared with traditional pyrometallurgy method. However, the bioleaching efficiency is unsatisfactory owing to the passivation film formed on the minerals surface. It is of particular interest to know the dissolution and passivation mechanism of sulfide minerals in the presence of microorganism. Although bioleaching can be useful in extracting metals, it is a double-edged sword. Metallurgical activities have caused serious environmental problems such as acid mine drainage (AMD). The understanding of some common sulfide minerals bioleaching processes and protection of Amd environment is reviewed in this article.
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The bacterial diversity and dynamics in the leaching solution were analyzed during bioleaching of low-grade copper sulfide ore in the presence of seawater in this study. The results indicated a promoting response of appropriate-proportion seawater to bioleaching with improved copper recoveries. A maximum of 84.70% copper recovery was obtained in the presence of 20.00% seawater in contrast to only 72.49% in its absence. The experiments verified that seawater owned a great influence on Attached bacteria and bacterial species. 16S rDNA analysis illustrated that bacterial species decreased distinctly in the presence of seawater. Little difference between blank sample (no seawater) and sample adding 20.00% seawater was indicated by beta diversity index. Bacteria (including Acidithiobacillus ferrooxidans, Sphingomonas leidyi and Lactobacillus acetotolerans) were influenced significantly after adding seawater. Acidithiobacillus ferrooxidans accounted for the highest proportion of the community whether seawater was added or not during bioleaching.
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Compared with the traditional pyrometallurgical process, copper bioleaching has distinctive advantages of high efficiency and lower cost, enabling efficiently extracts of valuable metal resources from copper sulfides. Moreover, during long-term industrial applications of bioleaching, many regulatory enhancements and technological methods are used to accelerate the interfacial reactions. With advances in microbial genetic and sequencing technologies, bacterial communities and their mechanisms in bioleaching systems have been revealed gradually. The bacterial proliferation and dissolution of sulfide ores by a bacterial community depends on the pH, temperature, oxygen, reaction product regulation, additives, and passivation substances, among other factors. The internal relationship among the influencing factors and the succession of microorganism diversity are discussed and reviewed in this paper. This paper is intended to provide a good reference for studies related to enhanced bioleaching.
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Bacteria community and copper recovery in presence of acid-processed rice straw (ARW) were explored during low-grade copper sulphide bioleaching. The results indicated a strongly promoting response of appropriate-quality ARW with improved bacteria concentration and enhanced copper recovery. The highest bacteria concentration reached 9.54 × 107 cells·mL-1 with an increase by 69.15%. And a maximum of 95.32% copper leaching rate with a relatively low Fe3+ concentration (329.00 mg·L-1) was obtained in presence of 1.0 g powdered ARW compared to only 83.40% in its absence. That is due to less development of passivation layer formed by Fe3+ hydrolysis, which is contributed by reducing ARW. 16S rDNA analysis illustrated the dominant leaching bacteria (Acidithiobacillus ferrooxidans) was influenced significantly, whose proportion reached 40.38% to the total bacteria when the ARW was added compared to 15.92% in its absence. And Stenotrophomonas accounted for the highest proportion of the bacteria community throughout bioleaching process.
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Nowadays, due to fast global industrial progress and near diminution of high-grade ore reserves, there has been massive call to cost-effectively process the resources of low-grade ores and industrial effluents for metal extraction. However, conventional approaches cannot be used to process such resources due to high capital cost and energy, also causing environmental pollution. Alternatively, bioleaching is highly environmental friendly and economic method to process such resources. Metal recovery from metal sulfide ore is carried out by chemolithotrophic bacteria like Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans. The same is done by heterotrophic microorganisms in non-sulfide ores. Additionally, for gold and copper extractions, bioleaching is used to extract cobalt, zinc, nickel, and uranium from low-grade ores and industrial effluents. In this review, the fundamental process of bioleaching from low-grade metal sulfide ores are discussed with emphasis on mechanism, types, pathways, techniques, and bioleaching development.
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A process of the high temperature ferric leaching of the copper-zinc concentrate and pyrite product during a two-step biohydrometallurgical technology was studied. It was shown that the use of the galvanic effect during the leaching of the copper-zinc concentrate enabled to obtain a copper concentrate with low zinc content in the relatively short time (approximately 5.7 h), while zinc concentration in the liquid phase was sufficient for zinc and copper recovery by extraction and cementation, respectively. Zinc content in the concentrate decreased from 7.36 to 0.5% in the process of leaching. The recovery of zinc and copper into the liquid phase was 96.1 and 40.3%, respectively. The leaching of copper-zinc pyrite product and galvanic interactions of minerals made it possible to recover nonferrous metals from it almost completely and to leave the main amount of sulfur and iron in leach residues. Operation of the laboratory unit with the use of bioregeneration of the liquid phase showed the principal possibility of functioning of a two-step biohydrometallurgical technology under semi-continuous conditions with the closed cycle of technological flows. Zinc content decreased from 15.25 to 1.3% during the first step of the leaching process, whereas during the second (biological) step it declined to 1.03% (within 24 h). The recovery of zinc and copper into the liquid phase was 92.6 and 54.6%, respectively. Flow sheet of the copper-zinc concentrate treatment, which can serve as a basis for modernization of the treatment of sulfidic raw materials, is proposed.
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Conventional leaching methods for Manganese (Mn) recovery require strong acids and are threatening to the environment. Alternatively, the use of microbes for Mn recovery is environment friendly in nature. The present investigation compares the capacity of pure and mixed cultures of native bacterial strains for bioleaching of low grade Mn ores. The ability of the isolated microorganisms to recover Mn was evaluated in shake flasks for 20 days under optimized conditions of pulp density (2%), sucrose concentration (2/g/100 ml), initial pH 6.5 and 30 °C incubation temperature. In pure culture form, Acinetobacter sp. MSB 5 (70%) was found to have a higher bioleaching potential than Lysinibacillus sp. MSB 11 (67%). Mixed culture of Acinetobacter sp. MSB 5 and Lysinibacillus sp. MSB 11 was found to perform better than the pure cultures with 74% extraction of Mn. The presence of mixed culture increased the dissolution rate and the recovery percentage of Mn. The respective growth pattern of the cultures was in synchronisation to their Mn bioleaching performances. This study underlines the importance of mixed cultures and, Mn solubilising activity of native bacterial strains for efficient Mn biorecovery.
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Oxidative dissolution of chalcopyrite at ambient temperatures is generally slow and subject to passivation, posing a major challenge for developing bioleaching applications for this recalcitrant mineral. Chloride is known to enhance the chemical leaching of chalcopyrite, but much of this effect has been demonstrated at elevated temperatures. This study was undertaken to test whether 100–200 mM Na-chloride enhances the chemical and bacterial leaching of chalcopyrite in shake flasks and stirred tank bioreactor conditions at mesophilic temperatures. Acidithiobacillus ferrooxidans, Acidithiobacillus thiooxidans and abiotic controls were employed for the leaching experiments. Addition of Na-chloride to the bioleaching suspension inhibited the formation of secondary phases from chalcopyrite and decreased the Fe(III) precipitation. Neither elemen-tal S nor secondary Cu-sulfides were detected in solid residues by X-ray diffraction. Chalcopyrite leaching was enhanced when the solution contained bacteria, ferrous iron and Na-chloride under low redox potential (b450 mV) conditions. Scanning electron micrographs and energy-dispersive analysis of X-rays revealed the presence of precipitates that were identified as brushite and jarosites in solid residues. Minor amounts of gypsum may also have been present. Electrochemical analysis of solid residues was in concurrence of the differential effects between chemical controls, chloride ions, and bacteria. Electrochemical impedance spectroscopy was used to characterize interfacial changes on chalcopyrite surface caused by different bioleaching conditions. In abiotic controls, the impedance signal stabilized after 28 days, indicating the lack of changes on mineral surface thereafter, but with more resistive behavior than chalcopyrite itself. For bioleached samples, the signal suggested some capacitive response with time owing to the formation of less con-ductive precipitates. At Bode-phase angle plots (middle frequency), a new time constant was observed that was associated with the formation of jarosite, possibly also with minor amount or elemental S, although this interme-diate could not be verified by XRD. Real impedance vs. frequency plots indicated that the bioleaching continued to modify the chalcopyrite/solution interface even after 42 days.
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The chemolithoautotrophic bacterium Acidithiobacillus ferrooxidans has been known as an aerobe that respires on iron and sulfur. Here we show that the bacterium could chemolithoautotrophically grow not only on H2/O2 under aerobic conditions but also on H2/Fe3+, H2/S0, or S0/Fe3+ under anaerobic conditions. Anaerobic respiration using Fe3+ or S0 as an electron acceptor and H2 or S0 as an electron donor serves as a primary energy source of the bacterium. Anaerobic respiration based on reduction of Fe3+ induced the bacterium to synthesize significant amounts of a c-type cytochrome that was purified as an acid-stable and soluble 28-kDa monomer. The purified cytochrome in the oxidized form was reduced in the presence of the crude extract, and the reduced cytochrome was reoxidized by Fe3+. Respiration based on reduction of Fe3+ coupled to oxidation of a c-type cytochrome may be involved in the primary mechanism of energy production in the bacterium on anaerobic iron respiration.
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This study investigates the biooxidation of a refractory gold concentrate using a mixed culture of acidophilic mesophiles, moderate thermophiles and extreme thermophiles and their effect on the subsequent cyanidation and gold recovery. The experiments with high % solids using mixed mesophiles showed better oxidation potential compared to moderate thermophiles and extreme thermophiles. However, the extreme thermophiles performed better than mesophiles and moderate thermophiles during the biooxidation with
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Heap bioleaching of low grade chalcopyrite (CuFeS2) was carried out in 1000 tons scale over a time period of 383 days. Bacterial solution was prepared and re‐circulated in specially designed BACFOX (BACterial Film OXidation) tank. The micro‐organisms used in the pilot scale were a mixed culture of acidophilic bacteria predominantly of the Acidithiobacillus ferrooxidans strain. Effect of rest period, solution recirculation, acid concentration, frequency of solution transfers and seasonal effects on copper recoveryweremonitored. The leaching studies showed a cumulative copper dissolution rate of 0.14% per day (2.37 kg d−1). The overall recovery of the heapwas 30%. Variation in leaching efficiency and some of the precautionary measures to improve performance of heap bioleaching are also discussed.
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Copper silica catalyst precursors have been characterized by diffuse reflectance infrared Fourier transform spectroscopy. The measurements were performed both under atmospheric conditions and under controlled gasatmospheres at elevated temperatures. Two reflection bands at 3615 and 690 cm-1 have been attributed to hydroxyl vibrations associated with the presence of copper ions highly dispersed over the silica surface. Calcination of a catalyst precursor at 800 K led to the disappearance of the copper-related surface hydroxyl groups.
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Pyrite oxidation rates were examined at various concentrations of dissolved oxygen (DO) in the presence of the sulfur and iron oxidizer Acidithiobacillus ferrooxidans. Five different batch experiments were performed at room temperature for 75 days under various DO levels (273, 129, 64.8, 13.2, and ≤0.006 μM), containing pyrite grains (particle size 63–250 μm) and a modified 9K nutrient medium at pH 3. The reactors were inoculated with A. ferrooxidans. In all experiments, pH decreased with time and sulfur and iron were released to the solution, indicating pyrite oxidation at all DO levels. Pyrite oxidation rates (ca. 5×10−10 mol m−2 s−1 at 273 μM DO) from all experiments showed positive correlation with DO, Fe(III), and bacterial concentration. These rates were significantly slower than rates presented in other published studies, but this is probably due to the significantly greater Fe(III) concentration at lower pH in these previous studies. The results obtained in this study suggest that ferric iron reduction at the pyrite surface is the primarily mechanism for microbial pyrite oxidation in the presence of DO. The results from our study support the indirect mechanism of sulfide oxidation, where A. ferrooxidans oxidizes ferrous iron in the presence of DO, which then oxidizes pyrite.
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The effect of silver ion, silver sulfide and silver-bearing concentrate (Ag–C) on the bioleaching of chalcopyrite has been investigated. It has been found that the addition of silver-bearing catalyst greatly enhanced copper dissolution from chalcopyrite and copper ores. The dissolved copper from chalcopyrite ore was increased from 25% to 75%, 65% and 67%, respectively, by addition of 0.32 g Ag, 4 g argentite (Ag2S) and 20 g Ag–C, per kilogram of ore after 20-day bioleaching in shake flasks. The bioleaching tests for a column charged with 18 kg chalcopyrite-containing waste rock showed that the copper extraction increased from 3.4% to 21.7% and 16.5%, respectively, by using 0.21 g Ag2S and 15 g Ag–C per kilogram of rock. The results indicated the possibility of using silver-bearing concentrate as an effective and cheap catalyst for bioleaching of chalcopyrite ore instead of the expensive silver. The mechanism of enhancement of chalcopyrite bioleaching in these systems was discussed, based on the “mixed potential model”, the mineralogy of silver-bearing concentrate as well as by using X-ray diffraction and electrochemical measurement.
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Chalcopyrite passivation greatly reduces the yields from leaching and bioleaching but the problem has not been successfully resolved. Passivation involves the formation of a layer of secondary minerals on chalcopyrite surface, which becomes a diffusion barrier to fluxes of reactants and products. This study aims to identify secondary minerals formed during chalcopyrite passivation in the presence of iron- and sulfur-oxidizing bacteria (Acidithiobacillus ferrooxidans) in mineral salts solution. The minerals were characterized with X-ray diffraction, Fourier transform-infrared spectroscopy, and Raman spectroscopy. Potassium jarosite was the initial product covering chalcopyrite grains, followed by the formation of ammonio-jarosite. Covellite and elemental sulfur were also detected in the passivation layer. The results suggest that passivation may be reduced by controlling jarosite precipitation and prior acclimatization of bacteria to oxidize CuS and elemental S in the presence of ferrous and ferric iron.
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Abstract Bioleaching of a low grade chalcopyrite (ball mill spillage material) was tested for copper recovery in shake flasks. The original samples (as received) were thermally activated (600°C, 30 min) to notice the change in physico-chemical and mineralogical characteristics of the host rock and subsequently its effect on copper recovery. A mixed culture of acidophilic chemolithotrophic bacterial consortium predominantly entailing Acidithiobacillus fer- rooxidans strain was used for bioleaching studies and optimization of process parameters of both original and thermally activated samples. Mineralogical characteriza- tion studies indicated the presence of chalcopyrite, pyrite in the silicate matrix of the granitic rock. Field emission scanning electron microscopy coupled with Energy dispersive spectroscopy (FESEM-EDS) and X-ray Fluor- escence (XRF) analysis indicated mostly SiO2. With pH 2, pulp density 10% w/v, inoculum 10% v/v, temperature 30°C, 150 r$min–1 ,49% copper could be recovered in 30 days from the finest particle size ( – 1 + 0.75 mm) of the original spillage sample. Under similar conditions 95% copper could be recovered from the thermally activated sample with the same size fraction in 10 days. The study revealed that thermal activation leads to volume expansion in the rock with the development of cracks, micro and macro pores on its surface, thereby enabling bacterial solution to penetrate more easily into the body, facilitating enhanced copper dissolution. Keywords ball mill spillage, thermal activation, bioleach- ing, copper
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Meso-acidophilic bacterial leaching of ball mill spillage (containing chalcopyrite >80%) was carried out in an innovative two-step bioleaching method. The major drawback of meso-acidophilic bioleaching limiting industrial application is the passivation phenomenon over the ore surfaces in iron-sulfur rich environments. In the present study, we present a novel wash solution that efficiently removed the passivation layer. FTIR characterization of the bioleached sample indicated that the residues could be further leached to recover extra copper after wash solution application. XRD study indicated accumulation of sulfates (SO(4)(-)) of Na, K, Fe and oxy hydroxides of iron [FeO(OH)] in the form of jarosite outlining the passivation layer. SEM, FESEM-EDS studies indicated severe corrosion effects of the wash solution on the passivation layer. Two step bioleaching of the ore sample yielded 32.6% copper in 68days in the first interlude and post wash solution application yielded 10.8% additional copper.
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M/S Hindustan Copper Limited (HCL), India generates large amounts of lean sulfide ores of copper. The current production of lean copper ores in India is 0.55 million tons with ∼0.3% average copper content. Heap-bioleaching of the lean copper ores in 15 and 30 ton scales was undertaken at IMMT, Bhubaneswar. The leaching study showed 0.09% dissolution of copper from the ore body per day. The leach liquor was processed through solvent extraction and electrowinning. Extraction of copper from the actual leach liquor was carried out with 1.5% LIX 622N in kerosene with zero co-extraction of iron. The copper-free raffinate was fed back to the leaching unit. Stripping of copper from the loaded organic was carried out with 180 kg/m3 H2SO4. The copper pregnant electrolyte was passed through a carbon column to make it free from entrained organic and was fed to the electrowinning unit. The increase in current efficiency was due to the increase in the concentration of electrolyte. The energy consumption was 1.7 kWh/kg at a flow rate of 4.5 L/h. Smooth and bright sheets of copper of 99.99% purity were obtained.
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Silico-antimonate as inorganic ion exchange material has been synthesized and characterized using different available tools (X-ray diffraction (XRD) pattern, X-ray fluorescence, infrared spectroscopy and differential thermal analysis). From the analysis data, the empirical formula of silico-antimonate was obtained to be H2SiSb4O13·10H2O. Sorption kinetics for Cu2+, Zn2+, Cd2+ and Ni2+ ions on silico-antimonate were studied and found to be follow the first order kinetics obeying the Freundlich isotherm over the entire range for the bulk concentration of the metal ions. Thermodynamic parameters (i.e. ΔG°, ΔS° and ΔH°) have also been calculated for the adsorption of Cu2+, Zn2+, Cd2+ and Ni2+ ions on silico-antimonate showing that the overall adsorption process is spontaneous and exothermic.
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Nickel laterites represent the major ore reserves of this base metal present in the lithosphere. However, processing these ores by conventional technologies involves considerable energy or reagent expenditure and consequently is less cost-effective than extracting nickel from sulfide ores. Biological options, using metal-complexing organic acids and mineral acids generated by fungi and bacteria, have been investigated but generally found to be ineffective in terms of extraction dynamics or yields. We have examined the possibility of using bacteria that can bring about the reductive dissolution of ferric iron minerals and thereby facilitate the extraction of nickel from a lateritic ore at relatively low (<30-45 degrees C) temperatures. Four species of iron-reducing acidophilic bacteria were screened for their abilities to solubilise nickel from a limonitic laterite ore in which the major iron mineral present was goethite. One of these (Acidithiobacillus ferrooxidans) was selected for further study only the basis of it being able to use a cost-effective energy source (elemental sulfur) to mediate the dissolution of goethite at mildly acidic conditions (pH < 2). Cultures were set up in 2 L bioreactors, maintained at pH 1.8 (+/-0.1) and 30 degrees C. and initially aerated (to promote growth of the bacteria on sulfur) and then switched to anaerobic conditions when nickel laterite ore (crushed to <6 mm, with a nickel grade of 0.5%) was added. Over 70% of the nickel present in the ore was solubilised within 14 days, and solubilised metals remained in solution due to the low pH of the leachate. In contrast, only 10% of the nickel was solubilised (by non-reductive acid dissolution) when the cultures were continuously aerated. The results suggest that biological processing of limonitic nickel laterites is technically feasible and, more generically, that reductive dissolution can be used to bioprocess ferric oxide mineral ores.
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The formation and consumption of elemental S were investigated in the bioleaching of chalcopyrite within and without a CE dialysis membrane in Acidithiobacillus caldus cultures. The bacteria were supplemented with tetrathionate outside the membrane. XPS analysis showed that monosulfide species and elemental S were formed on CuFeS 2 surface regardless of the enclosure in the dialysis membrane. They diminished over time in the inoculated systems. In the membrane enclosure, colloidal S partially dissolves and can pass the dialysis membrane for bacterial oxidation to sulfuric acid. Anaerobic pre-oxidation of CuFeS 2 by Fe 3+ produced S-rich deposition on mineral surface. The solubilization of Cu from membrane-enclosed pre-oxidized chalcopyrite in the A. caldus culture was much slower as compared to direct contact with bac-teria. The difference is attributed to slow diffusion through the dialysis membrane as well as clogging caused by polymerized S on the inside of the membrane.
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Fourier Transform Infrared (FTIR) spectroscopy, thermal analysis -Differential Scanning Calorimetry (DSC) and Thermo-Gravimetry (TG-DTG) were used to study the dehydration behavior of synthetic goethite and two naturally occurring goethite samples (Natural 1 and Natural 2) from Banded Iron Formation (BIF), at C.S. Halli, Chitradurg district, Karnataka, India. Goethites and its dehydration products were also identified by powder X-ray Diffraction (XRD) method. The dehydration temperatures were at 538, 567 and 578 K for synthetic, Natural 1 and 2 goethite, respectively. On approaching the dehydration temperature, infrared active modes of the hydroxyl groups have shown distinct variations. The peak position for the stretching mode around 3150 cm−1 was shifted upwards, while that for in-plane- deformation mode around 890 cm−1 was down shifted indicating weakening of strength of the hydrogen bonding. No intermediate phase, so called hydro-hematite, was observed in these studies. The total absorbance (area under the peak) of these modes have shown the Arrehenius type behavior in the temperature range 500–600 K, using which the activation energy for the dehydration process was estimated as 71, 103 and 85 kJ/mol for synthetic, Natural 1 and 2 goethites respectively.
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Low grade copper ore (ball mill spillage) obtained from Malanjkhand Copper Mine was processed through heap bioleaching at pilot scale. Bioleach liquor (Pregnant Leach Solution) from the heap contains (g/L of) Cu (II) 0.45, Fe (III) 0.838, Zn (II) 0.006, Ni (II) 0.0014, Mn (II) 0.011 and Pb (IV) 0.004. Solvent extraction of copper from Pregnant Leach Solution was carried out using LIX 984N-C. Effect of different operational factors such as equilibrium pH (pHe), extractant concentration, strip solution concentration, phase ratio was examined to optimize the condition for selective and quantitative extraction of copper. Based on the results of extraction as well as stripping isotherm, a 6-cycle counter current simulation study (CCS) was conducted for the conformational study. The extraction of copper was quantitative in 2-stages using 1.5% (v/v) LIX 984N-C at A: O ratio of 1:2 and pHe 1.85. The CCS condition (two stages, phase ratio A:O = 1:4) obtained from the stripping isotherm study, further attributes to the enrichment (4 folds) of copper concentration in the strip solution.