Rajesh Kumar Jyothi

CSIRO Mineral · Hydrometallurgy Innovations

Uranyl ammonium carbonate (AUC), with the chemical formula UO2CO3·2(NH4)2CO3, plays a crucial role in the wet conversion of uranium hexafluoride (UF6) into uranium dioxide (UO2) or triuranium octaoxide (U3O8) for nuclear fuel production, and is used in commercial and research reactors. In this study, the precipitation of AUC from uranyl fluoride (U...

As climate change concerns and the demand for sustainable and environmentally friendly energy sources grows, recent advancements in nuclear power technologies suggest promising achievements in using thorium as an alternative nuclear fuel. This study presents a comprehensive analysis of thorium resources worldwide, with a particular focus on their d...

Due to their comparable physicochemical characteristics, light rare earth elements (LREEs), such as lanthanum (La), cerium (Ce), praseodymium (Pr), and neodymium (Nd), the separation of these elements is a challenging process. In this study, a strategy involving hydrometallurgical unit operations is presented, including oxidation, precipitation, so...

Thorium is a naturally occurring radioactive element that has been identified as a potential alternative fuel for nuclear energy production. Additionally, thorium-based nuclear reactors have inherent safety features that reduce the risk of nuclear accidents and proliferation. As a result, there has been growing interest in the development of thoriu...

One of the most harmful air contaminants is nitrogen oxides (NOX) produced usually in combustion processes. To reduce the effluents, the most effective technology to date is selective catalytic reduction (SCR) where nitrogen oxides are reduced into nitrogen to be released freely. Due to the increasingly strict environmental regulations, the demand...

Nd-Fe-B magnets find wide range of applications due to its high magnetic properties. At its end-of-life, huge quantity of scrap Nd-Fe-B magnetsScrap Nd-Fe-B magnets are generated, which are promising alternative resource for rare earth elements (REEsREEs). RecyclingRecyclingof scrap Nd-Fe-B magnetsScrap Nd-Fe-B magnets will mitigate the demand supp...

Systematic studies were carried out to leach out rare earths and recover thorium from Korean monazite. Monazite was processed with acid baking process (sulfation) where rare earth elements (REEs) and thorium phosphates were transformed to water-soluble sulfates. Various experimental factors such as temperature, H2SO4/monazite concentrate ratio and...

The Nd-Fe-B permanent magnet was treated through integrated hydrometallurgical approach to recover neodymium. Leaching kinetics and process optimization using dilute HCl was investigated. The kinetics results ensures on following of leaching behaviour of Nd to Shrinking-Core model governed by diffusion control model (1-2X/3-(1-X) 2/3). The kinetic...

Most neglected part of the scrap computers are the keyboards, which are generally incinerated by the informal recycling sectors creating environmental pollution and leads to the wastage of precious metallic contents present in it. Present paper is focused on a novel chemical processing technique developed to recover silver (Ag) as value added produ...

A continuous counter-current extraction for the selective recovery of thorium (Th) and uranium (U) from the Yen Phu (Vietnam) rare earth concentrate leach solutions was systematically studied. The primary amine N1923 was used as an extractant which was prepared in the isoparaffin IP-2028 diluent. Thorium and uranium were selectively recovered in a...

The potential of cellulose nanocomposites in the new-generation super-performing nanomaterials is huge, primarily in medical and environment sectors, and secondarily in food, paper, and cosmetic sectors. Despite substantial illumination on the molecular aspects of cellulose synthesis, various process features, namely, cellular export of the nascent...

Korea Institute of Geoscience and Mineral Resources (KIGAM), which is a unique government-funded Geoscience research organization in Korea, has researched and devised many technologies on mineral processing and extractive metallurgy for more than 70 years. In addition, several recycling processes have much studied from lab scale to pilot plant scal...

Selective catalytic reduction (SCR) is the best technology to reduce the nitrogen oxides (NOx) emissions in industries. Due to the increasing demand and the limited lifespan of them, after deactivation, they usually end up in landfills posing a major environmental issue. Most catalysts for stationary applications contain around 0.5–1.5% wt V2O5 and...

Vanadium and tungsten ion adsorption and desorption characteristics and separation conditions were investigated using a simple porous anion-exchange resin. Initially, systematic experimental research was performed using synthetic aqueous vanadium and tungsten solutions. To evaluate the vanadium and tungsten (50-500 mg L-1) isotherm parameters, adso...

The chapter deals with the problem of the recycling of a spent selective catalytic reduction (SCR) catalyst used originally to convert nitrogen oxides into N2 to comply with the environmental air emissions regulations. Spent SCR catalysts are considered hazardous waste due to the presence of vanadium and tungsten, which are also strategic metals in...

Nickel metal hydride (NiMH) batteries are extensively used in the manufacturing of portable electronic devices as well as electric vehicles due to their specific properties including high energy density, precise volume, resistance to overcharge, etc. These NiMH batteries contain significant amounts of rare earth metals (REMs) along with Co and Ni w...

Non-availability of rich primary resources of rare earth metals (REMs) and the generation of huge amounts of discarded magnets containing REMs, compelled the researchers to explore the possibilities for the recovery of REMs from discarded magnets. Therefore, the present paper reports the recovery of REMs (Nd, Pr, and Dy) from discarded Nd-Fe-B magn...

The present paper addresses the preparation and characterization of anhydrous oxygen-free rare earth materials, such as terbium fluoride (TbF3). The fluorination of terbium oxide (Tb4O7) by ammonium bifluoride (NH4HF2) to prepare anhydrous TbF3 was reported in this work. The parameters affecting fluorination were studied, including the fluorination...

Spent catalyst, containing vanadium and tungsten oxide in a TiO2 glass fiber matrix, pose a risk of environmental contamination due to the high toxicity of its metal oxides if leached into the soil when disposed in landfills. Due to the increasing demand of metals and the continuous depletion of primary resources there is an growing necessity for r...

An environmentally sound process was investigated as feasible to extract and separate rare earths from the synthetic leach liquors prepared based on waste permanent magnets composition analogs. Solvent extraction methods were used to screen different extractants to optimize and suggest the proper extraction system to recovery the different rare ear...

Spent catalyst, containing vanadium and tungsten oxide in a TiO2 glass fiber matrix, pose a risk of environmental contamination due to the high toxicity of its metal oxides if leached into the soil when disposed in landfills. Due to the increasing demand of metals and the continuous depletion of primary resources there is an growing necessity for r...

The present chapter displays an overview of rare earth elements properties, deposits, trend charts about global REEs production, reserves from 2009 to 2019, and shows a comprehensive review on the REEs production and consumption of the lead countries like China. In the second part, the author describes how the rapid surge in global energy needs has...

Rare earth elements, by virtue of their role in technological advancements, have become critical commodities over the last few decades. The emerging awareness of environmental pollution associated with primary ore mining and the need for processes to preserve these non-renewable minerals, coupled with the attempt to break China’s monopoly of the RE...

Management of fly ash is a global challenge at present scenario due to its huge generation from various industries. Due to direct disposal into the environment process, it becomes serious concern in context contamination vis-a-vis loss of valuable metals. To overcome these issues the valuable metal as well as toxic heavy metals can be recovered and...

In view of increasing global demand of rare earth metals (REMs), less availability and limited natural resources compelled the researchers to develop the feasible processes to recover REMs from alternative secondary resources. Present book chapter is focused to explore possibility of coal bottom ash utilization for REMs extraction as well as highli...

In this chapter, response to the elimination from their water flows of carbofuran was checked by the dried capsicum annuam biochar (CABC). Char at 300 °C is produced from capsicum annuam stem to eradicate carbofuran from the watershed system. Capsicum annuam (CA) and capsicum annuam biochar (CABC) were tested for their physicochemical characteristi...

This book presents the state of art of the several advanced approaches to beneficiation of coal. The influence of recent technology attains the advantages of processing coal, purification studies, rheological behavior, and the mineral beneficiation. The experts collected in this volume have contributed significantly to the enrichment in the in dept...

Rare earths (REs) playing key role in new modern lives; REs were having numerous applications in the areas of electrical, electronic fields. Hydrometallurgy, the aqueous processing of metal ions tool is the cheapest and convenient for REs recovery from primary resources (Ores and Minerals) and secondary resources (Industrial wastes and scraps). Cou...

This study addressed the development of a continuous countercurrent extraction-scrubbing-stripping technique using a mixture of primary and tertiary amines as an effective extractant for both thorium (Th) and uranium (U) to simultaneously separate them from the leach solutions of xenotime concentrate from the Yen Phu mine (Vietnam). Systematic stud...

A complete extraction and stripping process to obtain enriched vanadium and tungsten concentrate from spent SCR catalyst leach liquor.

Rare earth elements (REEs) are vital components of high-tech electrical and electronic based materials. In the global scenario, the deposits of natural rare earth elements (REEs) are limited except for countries such as China. This has led to a dependence on major secondary rare earth-bearing sources such as battery waste, scrap alloy, spent magnet...

Microwave (MW) assisted leaching of copper (Cu) and chromium (Cr) from Cu-Cr spent catalyst was investigated. The MW assistance have many advantages over the regular leaching process and in consequences, the leaching time has been significantly reduced from 240 min to 120 min. The optimum condition; 900 Watt MW power, 2.0 min MW treatment time, 10%...

Rare earths (REs) play an important and key role in human lives in the twenty-first century; REs have numerous applications in the high-tech industry (electrical or electronic fields). Hydrometallurgy, the aqueous processing of metal ion tool, is the cheapest and most convenient for RE recovery from primary resources (ores and minerals) and seconda...

Separation and purification of thorium from monazite leach liquors was investigated by counter current extraction process. The Primene JM-T (mixture of highly branched C16 to C22 tertiary alkyl primary amine isomers) was used as an extractant and kerosene as a diluent for the present investigation. Extraction isotherm was plotted at the condition:...

This book examines the development, use, extraction, and recovery of rare earth metals. Rare earth elements (REEs) occupy a key role in daily life in industrial applications. They are one of the critical elements for energy and sustainable growth. REEs are utilized in many modern electrical and electronic devices such as smart phones, computers, LE...

Effective transportation of fly ash−water slurry through a pipeline from its generation site, a power plant, to a storage site by replacing commercial surfactants such as cetyl trimethyl ammonium bromide and sodium dodecyl sulfate by a natural dispersant extracted from Sapindus laurifolia was studied. The stability of fly ash slurry was determined...

The modeling of Yen Phu (Vietnam) xenotime concentrate leaching by sulfuric acid was studied for the purpose of optimizing the process. The response surface methodology (RSM) based on a central composite face-centered (CCF) design was empirically used to model the interactive effect of the independent variables, namely leaching temperatures of 250–...

The technology for extraction and recovery of the thorium from its source is one of the significant areas of research Present investigation deals on development of a process for extraction of thorium and its separation from the uranium and rare earths contained Korean monazite leach liquor. In the preliminary study, sulfuric acid treatment of monaz...

Alkali fusion method to extract vanadium and tungsten from spent SCR catalyst and to simultaneously prepare synthetic sodium titanate for the purpose of preparation of feedstock for TiO2 manufacturing by hydrometallurgical processing was investigated. Based on the Na2O-TiO2 phase diagram and experimentally obtained results, appropriate alkali-fusio...

The present paper deals with liquid-liquid extraction studies and the possible separation of light rare earths (LREs) from chloride solutions. Aromatic diluents such as benzene, toluene and xylene were tested for LREs extraction and possible separation from chloride solutions. Bis(2,4,4-triethylpentyl)phosphinic acid (trade name Cyanex® 272) was us...

This paper presents the direct extraction, which works by means of pressure leaching, of vanadium and tungsten from the spent SCR catalysts using a caustic soda. The experimental parameters were concentration of NaOH (aq), the particle size of the feedstock, the temperature, and the S/L ratio. The results of an assessment of the proposed method fou...

This paper deals with the recovery of tungsten as synthetic CaWO4 from spent V2O5-WO3/TiO2 (selective catalytic reduction, SCR) catalyst. The newly developed process included the systematic experimental steps (roasting, decomposition (using HCl solution), leaching (using NaOH), and precipitation) to recover tungsten as CaWO4. The results revealed t...

Modeling uranium dioxide pellet process from ammonium uranyl carbonate - derived uranium dioxide powder (UO2 ex-AUC powder) and predicting fuel rod temperature distribution were reported in the paper. Response surface methodology (RSM) and FRAPCON-4.0 code were used to model the process and to predict the fuel rod temperature under steady-state ope...

The processes of vanadium extraction, separation and recovery from spent de-sulfurization catalyst bio-leach liquor solutions were studied. Spent catalyst processing has mainly two benefits: to protect the environment from the effects of waste and to create wealth from waste. Numerous experimental parameters are optimized. The first step evaluated...

In this paper, extraction of vanadium and tungsten from spent selective catalytic reduction (SCR) catalyst by a soda roasting process was investigated. The leaching efficiency of tungsten significantly increased with the increases in Na2CO3 addition, roasting time and temperature. A leaching efficiency of tungsten was achieved with 92% when the spe...

The UO2 nuclear fuel pellet process for light water reactors (LWR) includes the conversion of uranium hexafluoride (UF6) into UO2 powder and the fabrication of UO2 pellets from such UO2 powder. In the paper, studies on UO2 pellet process from ammonium diuranate-derived uranium dioxide powder (UO2 ex-ADU powder) were reported. The UO2 ex-ADU powders...

21st century is electronic revolution in human lives as well as energy is a one of the most significant task. Rare earth elements (REEs) occupies key role in our daily life as well as high-tech industrial applications. REEs are one of the energy critical elements, for sustainable growth, it depends on their utilization and re-use, reduce, recycling...

Rare earth metals are essential ingredients for the development of modern industry as well as designing and developing high technology products used in our daily lives. Consequently, the worldwide demand of rare earth metals is rising quickly and predicted to surpass the supply by 40,000 tons annually. However, their availability is declining, main...

In the paper, Brandon mathematical model that describes the relationship between the essential fabrication parameters [reduction temperature (TR), calcination temperature (TC), calcination time (tC) and reduction time (tR)] and specific surface area of ammonium diuranate (ADU)-derived UO2 powder products was established. The proposed models can be...

Macrocyclic compounds (crown ethers), specifically 18-crown-6 (18-C-6), benzo-15-crown-5 (B-15-C-5), di-benzo-18-crown-6 (DB-18-C-6) and di-cyclohexano-18-crown-6 (DC-18C-6), are used as extractants as well as synergists with amine-group extractants. Platinum and rhodium belong to platinum-group metals (PGMs) and have very similar ionic radii and s...

Rare earths (REs) recovery and processing becomes most important all over the globe due to their versatile applications in modern life. The present general article discusses REs extraction and possible separation and recovery methods from phosphoric acid media. Leaching studies are discussed followed by two extraction techniques: solvent extraction...

Uranium dioxide (UO2) powder has been widely used to prepare fuel pellets for commercial light water nuclear reactors. Among typical characteristics of the powder, specific surface area (SSA) is one of the most important parameter that determines the sintering ability of UO2 powder. This paper built up a mathematical model describing the effect of...

Synergistic extraction of uranium using amine combined with phosphorous based extractant systems was described. The present study focused on the continuous extraction processing of uranium to form precipitation under higher pH conditions and higher aqueous phase ratios. To address this, synergistic extraction studies were carried out with P-based e...

In the present study, extraction and separation possibilities have been established for boron and lithium from Uyuni salar brine. Diols were shown to be effective extraction reagents for boron. The present scientific study was developed with 2, 2, 4-trimethyM, 3-pentanediol (TPD) as an extractant system. For fixing the diluent system, various dilue...

The aimof the present study is to investigate the extraction, separation and recovery of the indivisible metals of dysprosium and neodymium from permanent magnets scrap (PMS) leach liquor solutions. Organo-phosphorous extractant namely 2-ethylhexyl phosphonic acid mono-2-ethylhexyl ester (PC 88A) was employed and optimised various experimental para...

Publication details, including instructions for authors and subscription information: (2015): Factors affect on bioremediation of Co(II) and Pb(II) onto Lonicera japonica flowers powder, Desalination and Water Treatment To link to this article: http://dx. Bioremediation is a low-cost eco-friendly separation technique for the treatment of pollutants...

The current study deals with the recovery process development for the rare earths (REs), i.e., dysprosium (Dy) and neodymium (Nd), metals from permanent magnet scraps leach liquors. Its main objective is the recovery of the rare earths (Dy and Nd) from permanent magnet scraps (PMSs). Introdutory experiments were carried out to get leach liquor solu...

Introduction Rare Earth Applications Status of USA in Rare Earths Applications South Korea Situation in South Korea Alternative sources for rare earth elements Gallium Applications Extraction of Gallium from Korean Redmud Yttrium Global demand and its Applications Yttrium Extraction from Korean Redmud Convergence Technologies Natural carbonation Ac...

Introduction Discussion Mineral Processing of Korean Ore Decomposition and Leaching of Concentrates Separation and Purification of Rare Earth Elements Preparation of Rare Earth Oxide Compound and Metal Summary Acknowledgements

In alumina production or alumina refining, bauxite is converted to alumina (aluminium oxide) The rare-earth elements (REEs) are a group of 17 chemically similar metallic elements (15 lanthanides, including scandium and yttrium). Rare earth elements play a key role in many industrial applications, petroleum refining, clean energy, automobile, electr...

Rare earth materials have an ever growing variety of applications in the modern and hitech technology. They apply to many an industry with crucial materials and they provide numerous a customers with benefits. Rare earth materials utilization increasing day-by-day in the worldwide, at the same time the resources is very limited in many countries li...

Solvent extraction and separation of vanadium from other associated metals such as Ca, Na, Fe, Mn, Al from sulfate solutions using various extractants like phosphorus based and amine- based extractants were studied. And the other experimental conditions were optimized as follows: pH influence, extractants influence, 3rd phase studies, extraction eq...

Rare earth metals (REMs) play a significant role in the manufacture of permanent magnets, fluorescent lamps, catalysts, medicines, super alloys etc. Recently, China, which controls 97% of world trade in REMs, imposed restriction on its export. Consequently, the global demand of REMs is escalating and is expected to exceed the supply by 40, 000 tonn...