Fig 1 - uploaded by Nikolas-Plutarch Benetis
Content may be subject to copyright.
Source publication
The production and distribution of quartz sand for the simplest uses as filters and absorbents, foundry sand, fillers, or abrasives and finally the high-tech industry is first discussed. A special category of ultra-pure quartz is the high quality and high value of experimental glassware in synthetic and analytical chemistry. Information about other...
Contexts in source publication
Context 1
... silica is ubiquitous, found in rock deposits of all geological eras and in all global locations. Fig.1. shows the temperature and pressure conditions at whichSiO 2 polymorphs are stable in a so-called phase diagram of SiO 2 . ...
Citations
... Depending on the intended use, HPQ has different tolerance limits for Al and Fe impurities. For example, the Al 2 O 3 and Fe 2 O 3 content of HPQ used in the production of semiconductor filters, (LCDs), and optical glass (used in cameras, optical instruments, and optical fibers for telecommunications), should be below 2000 ppm (0.2%) and 100 ppm (0.01%), respectively [32]. In extremely high-end applications, such as large-size silicon wafers, the Al content is required to be less than 8 ppm [4]; in this case, the SiO 2 content should be at least 99.99%. ...
Three quartz-rich geologic materials—vein quartz from the Great Bear Magmatic Zone, massive quartz from the Nechalacho rare earth deposit, and quartz sands from the Chedabucto silica sand deposit along the shores of the Northern Arm of the Great Slave Lake, Northwest Territories of Canada—were evaluated for their amenability to physical beneficiation into high-purity quartz (HPQ). The samples were subjected to various treatment processes, including crushing, grinding, calcining and quenching, acid leaching, wet high-intensity magnetic separation (WHIMS), and reverse flotation. After treatment, both the core and sand quartz samples met the requirements for HPQ, making them suitable for use in the production of semiconductor filters, liquid crystal displays (LCDs), and optical glass. However, the Al-bearing impurity content in the vein quartz products remained relatively high, and most of these impurities were dispersed in the quartz lattice, requiring further processing to meet the purity standards for HPQ required by these industries.
... For instance, in construction, it is a key component in concrete, ceramics, and bricks due to its reinforcement properties [8]. In electronics, chips and semiconductors are manufactured using silica crystals [9]. However, crystalline silica poses health risks due to the silanol group (SiOH) [10], especially in occupational settings where exposure to respirable crystals can lead to lung diseases such as silicosis [11]. ...
Silicon dioxide (SiO2), commonly known as silica, is a naturally occurring mineral extracted from the Earth’s crust. It is widely used in commercial products such as food, medicine, and dental ceramics. There are few studies on the health effects of pyrogenic and colloidal silica after ingestion. No research has compared the impact of microscale morphologies on mitochondrial activity in colon cells after acute exposure. The results show that crystalline and amorphous silica had a concentration-independent effect on cells, with an initial increase in mitochondrial activity followed by a decrease. Vitreous silica did not affect cells. Diatomaceous earth and pyrogenic silica had a concentration-dependent response, causing a reduction in mitochondrial activity as concentration increased. Diatomaceous earth triggered the highest cellular response, with mitochondrial activity ranging from 78.84% ± 12.34 at the highest concentration (1000 ppm) to 62.54% ± 17.43 at the lowest concentration (0.01 ppm) and an average H2O2 concentration of 1.48 ± 0.15 RLUs. This research advances our understanding of silica’s impact on human gastrointestinal cells, highlighting the need for ongoing exploration. These findings can improve risk mitigation strategies in silica-exposed environments.
... Early studies have shown that the impurity content of HPQ should be less than 50 ppm, i.e., that the purity of SiO 2 should be greater than 99.995% [2,5]. Vatalis et al. [6] suggested that quartz with a SiO 2 purity of 99.95% and a total impurity content of <500 ppm is HPQ, quartz with a purity of 99.5% to 99.8% can meet the requirements of the semiconductor filler, optical fiber, and liquid crystal display screen production industries, and quartz with a purity of <99.5% can be used in the transparent glass industry. In recent years, emerging glass industries have reduced the purity requirements of SiO 2 (quartz with a purity greater than 99.9% is high-purity quartz) [1,[7][8][9]. ...
A purification process including flotation separation, acid leaching, calcination, and water quenching was conducted to obtain high-purity quartz sand. The surface morphology of the quartz after flotation separation, acid leaching, calcination, and water quenching reveals that the cracks, pits, and cavities on the quartz surface can be deepened and enlarged, and the more fluid inclusions, the greater the number and openness of cracks, pits, and cavities. The specific surface area is positively correlated with the number of cracks, pits, and cavities, the opacity of quartz glass, and the number of bubbles in quartz glass. The results of Raman spectroscopy analysis reveal that the bubbles in quartz glass are composed of nitrogen, which excludes the possibility of bubble formation in quartz glass caused by the gas composition (i.e., H2O) of unburst fluid inclusions in quartz sand. The formation of bubbles in quartz glass is more likely to be related to a high specific surface area and porosity, which increase the surface adsorption performance of quartz and contribute to the adsorption of more gas. The presented results suggest that using these methods to reduce the content of fluid inclusions in quartz cannot effectively solve the problem of bubbles in quartz glass, and using quartz raw materials with no or minor fluid inclusions is still the key to ensuring the quality of quartz products.
... Figure 5 shows the variations in zeta potential of the glass fiber powder before and after the addition of BTA, OTA, DDA, PEA-D230, PEA-D400 and PEA-D2000 respectively. Without any collector present, the isoelectric point of the glass fiber powder is about 2.40, which is consistent with previous reports [10,11]. Upon the addition of the collector, there is a significant rightward shift in the isoelectric point, indicating that the collector has successfully adsorbed on the surface of the glass fiber powder [12,13]. ...
Improving the purity of glass fiber powder represents a crucial challenge that needs to be addressed in the development of the glass fiber industry. To investigate the flotation behavior of glass fiber powder and the adsorption mechanism of the collector on its surface, the effect of flotation time, collector type, and concentration in flotation experiments was studied. Zeta potential, Fourier transform infrared spectroscopy (FT-IR), and X-ray photoelectron spectroscopy (XPS) were used for systematic analysis. The results show that flotation effectively removes the visible impurities mixed in the glass fiber powder. The collection capacity of poly (propylene glycol) bis (2-aminopropyl ether) (PEA) generally surpasses that of conventional monoamine collectors. With the novel collector PEA, especially at a concentration of 6 × 10⁻⁵ mol/L of PEA-D2000, the flotation recovery rate of glass fiber powder can reach approximately 95%. Furthermore, a flotation mechanism for the glass fiber powder using amine-based collectors is proposed. It is adsorbed onto the surface of glass fiber powder through − NH3⁺/−NH2 groups, primarily by hydrogen bonding, and supplemented by electrostatic adsorption.
... Silica sand serves as the main source of silicon, a naturally occurring material that forms the basis for an extensive variety of modern technologies. It plays a crucial role in the production of solar cells and electronic chips, essential components at the core of the substantial technological advancements that moved the world into the twenty-first century (Wahab et al., 2022;Vatalis et al., 2015). As a result, researchers should pay greater attention to white sand, which is a strategic gem that has not been fully utilized. ...
Egypt is endowed with huge reserves of filler minerals, such as silica sand which form approximately 95% of the Earth's crust. The silica sand industry is used in many fields, such as pharmaceutical practices, chemicals, glass, ceramics, electronics , and photovoltaic industries. The aim of this study is to remove impurities from silica sand and apply surface modification processes to enhance its value for various industrial manufacturing applications. Various processing techniques , including classification, attrition scrubbing, magnetic separation, ultra-fine grinding and surface modification , were conducted throughout the study. The results indicated that attrition scrubbing to the classified size fraction of-0.6 + 0.1 mm was capable of reducing the iron concentration from 0.068% to 0.045%. Utilizing the Box-Behnken design, the optimal conditions for magnetic separation were identified, resulting in a decrease in iron content down to 0.012%. Simultaneously, the silica content increased from 99.05% to 99.76%. The results of ultrafine grinding using an attritor mill revealed that a grinding time of 2 hours is sufficient to reach a size suitable for the coating process. Surface modification of the produced ultrafine sand was conducted using polymers and silanes. The treated sand was characterized using SEM, zeta potential, adsorption density, and FTIR measurements. Notably, hydrophobicity increased , accompanied by an increase in particle size. Simultaneously, the surface becomes flatter, indicating the formation of a thin layer. Consequently, the coated sand proved to be a satisfactory material that met the criteria to be used as a filler in coating and paints.
... Quartz is mainly used in the manufacture of glass, as a filter material for water, and as a filler for the ceramic industry. Among other applications, high-purity quartz is used in photovoltaic cells [1]. Potassium feldspar (Kfs) is used to manufacture paints in the ceramic industry [2], especially for the removal of colored impurities [3] insulators and abrasives and for the production of electrodes [4]. ...
... In aqueous suspensions of feldspar and quartz particles, the free bonds are neutralized by OH − and H + species. Partial or total particle surface hydroxylation can form silanol groups [Si(OH) n ] [12], which is pure water dissociated through the reactions (1) and (2) [13]: ...
An improved method for producing high-purity quartz (Qtz) and potassium feldspar (Kfs) concentrates was developed using various chemical reagents. Froth flotation experiments on a Qtz–Kfs mixture showed that quartz could be selectively floated from Kfs in diluted hydrofluoric acid (HF) using a frother. Similarly, feldspar could be selectively floated from quartz. Recovery rates depended on reagent choice, pH levels, HF modifier dosage, and HF conditioning time. High recoveries and good grades were achieved for both quartz and feldspar at low pH levels. Among the five collectors tested, Brij C20 showed the highest recovery when used in conjunction with HF and a frother alone and a concentrate containing 82.8% quartz was obtained at a 96% recovery rate. Good recoveries were also achieved with collectors like Duomeen C and Flotigam V4343 for floating K-feldspar, with a Kfs concentrate of 99.9% purity at a 94% recovery. Lilaflot OT 55 and Duomeen TDO were less effective. The concentration of HF was 22 kg/t, which implies an important reduction with respect to the earlier research.
... The we ability of quar by various types of liquids and multi-component solutions plays an important role in many industries (for example, in petrochemistry, catalysis and carbon geostorage), medicine (for example, a as drug carrier) and mineral processing (for example, in flotation and flocculation processes as well as oil recovery) [1][2][3][4][5][6][7][8][9][10][11][12]. Quar is a bipolar solid whose surface tension results from the Lifshi -van der Waals (LW) and Lewis acid-base (AB) intermolecular interactions [13,14]. ...
The wettability of quartz by different liquids and solutions plays a very important role in practical applications. Hence, the wetting behaviour of ethanol (ET), rhamnolipid (RL) and Triton X-165 (TX165) aqueous solutions with regard to the quartz surface tension was investigated. The investigations were based on the contact angle measurements of water (W), formamide (F) and diiodomethane (D) as well as ET, RL and TX165 solutions on the quartz surface. The obtained results of the contact angle for W, F and D were used for the determination of quartz surface tension as well as its components and parameters using different approaches, whereas the results obtained for the aqueous solution of ET, RL and TX165 were considered with regard to their adsorption at the quartz–air, quartz–solution and solution–air interfaces as well as the solution interactions across the quartz–solution interface. The considerations of the relations between the contact angle and adsorption of solution components at different interfaces were based on the components and parameters of the quartz surface tension. They allow us to, among other things, establish the mechanism of the adsorption of individual components of the solution at the interfaces and standard Gibbs surface free energy of this adsorption.
... Taking Thrakon, a Greek company, as an example, they leverage the low impurity content of the Alada River quartz sand. After undergoing cleaning and drying processes, this sand serves as the primary component in construction mortar [11]. Quartzite is a metamorphic rock formed from siliceous rocks through regional metamorphism or contact metamorphism induced by hydrothermal activity. ...
Quartz deposits are widely dispersed in nature, but the presence of ore bodies capable of yielding high-purity quartz is exceedingly rare. As a result, the effective purification and processing of high-purity quartz from natural siliceous materials has emerged as a prominent area of research within the non-metallic mineral processing field. This article offers an overview of the current state of research and its limitations in quartz purification and processing technology in China, including the characteristics of quartz mineral resources, the geological origins of ore deposits, impurity forms in ores, and purification techniques. Drawing from examples of five distinct types of quartz ores—vein quartz, powder quartz, quartzite, granitic pegmatite, and pegmatitic granite—we delve into the inherent properties of quartz deposits, ores, and minerals from a mineralogical perspective, establishing their link to purification and processing methodologies. A fundamental challenge restraining the advancement of the high-purity quartz industry is the absence of criteria for evaluating and selecting high-purity quartz raw materials. Existing purification technologies grapple with issues such as intricate single mineral liberation, substantial acid consumption, high energy requirements, and protracted processing procedures. The lack of mineralogically based deep purification techniques presents a hurdle to the development of the high-purity quartz industry. Given the diversity of ore types, the pursuit of knowledge-driven design and the development of economically efficient, environmentally friendly, and streamlined new technologies for tackling the complexities of the purification process may constitute the future direction of our endeavors.
... It reserves about 20 billion tons of white sand distributed along the Red Sea coast, South Sinai, and Eastern Desert [1]. This sand is the primary supply of silicon, the naturally occurring material that is the foundation for a wide range of modern technology, including the manufacturing of solar cells and electronic chips, which are at the heart of the enormous technological boom that moved the world into the twenty-first century [2,3]. Therefore, white sand should receive more attention from Egyptian researchers, as it is a strategic treasure that has not been exploited sufficiently. ...
This work aims to successfully produce silica nanoparticles (SNPs) from Egyptian white sand using the fungal bioleaching process as a cost-effective and eco-friendly approach. The impact of fungus cultivation techniques (submerged culture SMC and solid-state culture SSC) on the characteristics of the produced SNPs has been investigated. In addition, the most promising fungal isolates for each culture method were selected and identified by morphological and molecular methods. The biosynthesized SNPs were fully characterized by DLS, FTIR, XRD, SEM, EDX, and HRTEM studies. DLS results showed that Aspergillus niger solid-state culture had developed SNPs with a mean particle size distribution of about 3.6 nm, whereas Penicillium crustosum submerged culture developed SNPs with 50.7 nm. SEM images revealed that the prepared SNPs under SMC and SSC have sphere-shaped particles with smooth surfaces and semi-homogeneous characteristics. Moreover, the HRTEM imaging confirmed the spherical shape with an average size of 3.5 and 28.8 nm for the nanosilica synthesized during solid-state and submerged culture, respectively. Based on the results, we recommended using SSC to produce silica nanoparticles from white sand with a small nano-size, high purity, and better economical production. The scientific advances focused on some particular fungi's capacity to manufacture SNPs with high purity, small size, and techniques that were both economical and environmentally beneficial.
Graphical Abstract
... The disadvantage of this technology is the need to substantially increase the carbon content of the melt, resulting in a substantial increase in the amount of carburizer (1 ton of alloy to 40 kg). Additionally, carburization must be carried out at elevated temperatures, which adversely affect the stability of the furnace lining [3]. This means that to smelt 1 ton of synthetic cast iron for metal filling using no more than 30% of steel scrap, 10-15 kg carburizer is required, and 90% of steel scrap requires at least 40 kg. ...
The purpose of the foundry is to provide the consumer with blanks for general machine-building (special) purposes which are as close as possible to the size of the future part in full compliance with the requirements. The competitiveness of these products is primarily dependent on the use of efficient and reliable smelting equipment which meets the necessary cost. The replacement of high-value ironworks and ironworks iron with steel scrap using induction melting furnaces (ICFs) reduces the cost of producing synthetic cast iron. However, this results in temperatures greater than 1500 °C, reduced lining stability and increased downtime of the smelter. As a result of the research carried out, a technology for the use of quartzite is proposed. Thereby, the purpose of this work is to establish temperature regimes for the smelting of synthetic pig iron, allowing the use in metal filling up to 70–90% of steel scrap; this leads to a reduction in the cost of purchasing bulk materials (depending on the brand of cast iron) up to 50% and, thus, increases the efficiency of synthetic cast iron smelting and castings production in general. After removal of the original moisture and the subsequent sintering of the manufactured lining, it provides the possibility of melting using the melting temperatures 1550–1600 °C. It increases the efficiency of the operation of the melting furnaces and eliminates the consumption of the ironworks and the melting of the cast iron in the blast furnace, as well as the cost of the lost alloy. As a result, metallurgical production will be able to reduce the volume of production and supply of cast iron for ironworks, which will improve their environmental situation during the production and processing of necessary raw materials.
