Quartz Mining Research Articles

The influence of compost amendments on bioaccumulation of potentially toxic elements by pea plant cultivated in mine degraded soils

Potential toxic metal (PTE) accumulation in soil and water is one of the major sources of food crop contamination. PTE remediation from soil can be enhanced by the addition of organic matter to the growing media. An experiment was carried out to investigate the effect of different organic amendments on the accumulation of PTEs in pea plant grown on mine degraded soils. Mining soils from chromite mine (CM), soap stone mine (SSM), manganese mine (MM), and quartz mine (QM) were mixed with vermicompost (VC), leaf mould (LC), and spent mushroom compost (SMC) along with garden soil at 1:1:1 ratio. Various growth and yield-related attributes of pea plant as well as PTE concentrations in soil and plants were studied. The highest Cd (2.62 mg kg−1) and Cr (13.6 mg kg−1) concentration was reported in CM soil, while Pb (23.3 mg kg−1) and Mn (59.2 mg kg−1) concentration in SSM and MM soil, respectively. Mining soils significantly reduced the plant growth and yield, while organic amendments reduced the PTE availability and increased pea plant growth. Comparing the various organic fertilizers used, it was observed that VC efficiently reduced Cd, Cr, Pb, and Mn uptake by pea plant, subsequently, improved pea plant growth and productivity. In order to assess the effects of various amendments on PTE health risk reduction, various risk indices including plant tranfser factor, average daily intake, health risk, target hazard quotient, and target cancer risk were also calculated and the results revealed that application of compost particularly VC significantly reduced the dietary intake and health risks of PTEs.

The Crystal Structure of Malhmoodite from Custer, South Dakota, USA

ABSTRACT An occurrence of malhmoodite, Fe2+Zr(PO4)2·4H2O, from the Scott's Rose Quartz mine, Custer County, South Dakota, USA, has been identified. It occurs as divergent groups of yellowish, flat-lying platy crystals on football-size masses of altered löllingite with scorodite, parasymplesite, karibibite, schneiderhöhnite, kahlerite, and zircon. An electron probe microanalysis of malhmoodite yielded an empirical formula (based on 12 O apfu) of Fe1.06(Zr1.10Hf0.03)Σ1.13[(P0.93As0.01)Σ0.94O4]2·4H2O. Single-crystal X-ray structure analysis shows that malhmoodite is the Fe-analogue of zigrasite, MgZr(PO4)2·4H2O. Malhmoodite is triclinic with space group P and unit-cell parameters a = 5.31200(10), b = 9.3419(3), c = 9.7062(3) Å, α = 97.6111(13), β = 91.9796(11), γ = 90.3628(12)°, V = 477.10(2) Å3, Z = 2, in contrast to the previously reported monoclinic symmetry with space group P21/c and unit-cell parameters a = 9.12(2), b = 5.42(1), c = 19.17(2) Å, β = 94.8(1)°, V = 944.26 Å3, Z = 4. The crystal structure of malhmoodite is characterized by sheets composed of ZrO6 octahedra sharing all vertices with PO4 tetrahedra. These sheets are parallel to (001) and are joined together by the FeO2(H2O)4 octahedra. The structure determination of malhmoodite, along with that of zigrasite, warrants a re-investigation of synthetic compounds M2+Zr(PO4)2·4H2O (M = Mn, Ni, Co, Cu, or Zn) that have been assumed previously to be monoclinic.

Country-specific carbon footprint and cumulative energy demand of metallurgical grade silicon production for silicon photovoltaics

The photovoltaic (PV) industry requires high-quality silica sand to produce metallurgical-grade silicon (MG-Si) for silicon PV (Si PV). However, high-quality deposits are scarce, and using lower-quality resources may increase the carbon footprint and cumulative energy demand (CED) of Si PV modules. The environmental impact of quartz mining and silica sand extraction for PV has not been updated in over 15 years. It's not representative of current methods used for low-quality sand and is not country-specific. As a result, PV production's environmental impact might be underestimated. We used life-cycle assessment to evaluate the carbon footprint and CED of quartz mining, silica sand extraction, and MG-Si production for high-quality (> 98% silica), industrial-grade (95% silica), and low-quality (65% silica) quartz deposits, which are necessary to calculate Si PV's energy and carbon payback time. The carbon footprint per metric ton of silica sand extraction increased from 22.7 kg CO2eq for high-quality quartz to 47.9 for industrial-grade and 86.7 for low-quality. China currently uses foreign industrial-grade quartz but plans to use low-quality domestic resources, which could increase the carbon footprint of producing one kg MG-Si from 12.1 to 16.5 kg CO2eq. The CED could increase from 188 to 286 MJ. We also investigated illegal mining's environmental impact. The carbon footprint and CED of MG-Si production decreased by 26 to 60% for illegal mines compared to legal mines. Illegal MG-Si production can be cheaper and have a lower carbon footprint, and therefore, third-party-supply-chain verifications are essential to ensure that PV doesn't contribute to the problem.

Quartz Mining Waste for Concrete Production: Environment and Public Health

Brazil, one of the largest ore producers in the world, holds 95% of the world’s quartz reserves. The aim of this research is to enhance mitigation measures in quartz ore exploration common in the Serra do Espinhaço Meridional region through the specific study of a mining venture. The three (3) phases of the study were: (1) characterization of the project under study and evaluation of the impacts generated; (2) evaluation of the economic feasibility of using the waste as a coarse aggregate for concrete production; (3) evaluation of the technical feasibility of reusing this waste through analysis of compressive strength. The results of the study show potential negative impacts on occupational health from the piles of disposed waste, specifically silicosis, caused by silica dust dispersed in the air. In the economic analysis, a decrease of 49.05% was verified in coarse aggregate cost through the use of the residue. The compressive strength of the concrete was 26.80 MPa when quartz residue was used and 29.2 MPa when limestone was used. The quartz residue generated by the venture can be reused as aggregate for the production of concrete, generating improvements in environmental and health aspects.

Air quality modeling for impact evaluation of a mica, feldspar, and quartz mine in Nellore district, Andhra Pradesh, India

Air quality modeling for impact evaluation of a mica, feldspar, and quartz mine in Nellore district, Andhra Pradesh, India

Influence of particle size-designed recycled mineral admixtures on the properties of cement-based composites

In this work, engineered recycled mineral admixtures were obtained from four different industrial residues: basic oxygen furnace slag, iron ore tailings, quartz mining tailings and quartzite mining tailings. The grinding performance was evaluated in two different programs and the characterization included chemical and mineralogical composition, particle morphology, and physical properties. Performance evaluations were carried out in blended pastes and mortars, including flow properties, hydration kinetics, soundness, pozzolanic activity, and compressive strength. Coarser-than-cement admixtures allowed better flow performance, greater dimensional stability and more economical production, while finer-than-cement admixtures improved mechanical performance by both filler effect and cementing activity.

Bioaccumulation of potentially toxic elements in spinach grown on contaminated soils amended with organic fertilizers and their subsequent human health risk

Soil pollution with potentially toxic elements is a significant environmental problem worldwide. Such soils need reclamation, utilizing environmentally friendly and cost-effective techniques. Therefore, a study was performed with an aim to evaluate the effect of different organic amendments on bioaccumulation of potentially toxic elements in spinach grown on contaminated soils. For the experiment, soils from various mines (manganese mine (MM), chromite mine (CM), quartz mine (QM), and soap stone mine (SSM)) were amended with organic fertilizers including spent mushroom compost (SMC), vermicompost (VC), and leaf compost (LC). Spinach was grown in pots containing 5 kg growing media at 1:1:1 by weight (garden soil:mining soil:organic fertilizer). Results indicated that mining soils and organic amendments significantly affected plant growth and yield parameters and potentially toxic elements’ content in spinach. Organic fertilizers amendment reduced potentially toxic elements’ availability, increased spinach growth, and reduced their related health risk indices (HRI). Among organic fertilizers, VC was more effective in reducing uptake of lead (Pb), manganese (Mn), chromium (Cr), and cadmium (Cd) by 81%, 59%, 74%, and 45%, respectively; improving spinach growth and yield; and reducing HRI.

Past human impact in a mountain forest: geoarchaeology of a medieval glass production and charcoal hearth site in the Erzgebirge, Germany

Since the twelfth century, forest areas in the upper reaches of the low mountain ranges of central Europe provided an important source of wood and charcoal especially for mining and smelting as well as glass production. In this case study from a site in the upper Erzgebirge region (Ore Mountains), results from archeological, geophysical, pedo-sedimentological, geochemical, anthracological, and palynological analyses have been closely linked to allow for a diachronic reconstruction of changing land use and varying intensities of human impact with a special focus on the fourteenth to the twentieth century. While human presence during the thirteenth century can only be assumed from archeological material, the establishment of glass kilns together with quartz mining shafts during the fourteenth century has left behind more prominent traces in the landscape. However, although glass production is generally assumed to have caused intensive deforestation, the impact on this site appears rather weak compared to the sixteenth century onwards, when charcoal production, probably associated with emerging mining activities in the region, became important. Local deforestation and soil erosion has been associated mainly with this later phase of charcoal production and may indicate that the human impact of glass production is sometimes overestimated.

Influence of high-charge and low-charge PCE-based superplasticizers on Portland cement pastes containing particle-size designed recycled mineral admixtures

Designand use of engineered recycled mineral admixtures obtained from industrial and mineral waste are promising strategies to increase the range of materials suitable for use in cement-based composites. In this work, Portland cement-blended pastes containing mineral admixtures designed for improving particle packing were evaluated in the presence of low- and high-charge polycarboxylate-based superplasticizers. The powders were obtained from basic oxygen furnace slag, iron ore tailings, quartz mining tailings, and quartzite mining tailings. The zeta-potentials of the particles were obtained via electrophoretic mobility. The flow properties were evaluated by rheological tests performed in a Couette type rheometer. The hydration kinetics was evaluated by isothermal calorimetry and an adapted method based on the Vicat needle test. The high-charge PCE and the finer mineral admixtures produced more stable blends. Coarser mineral admixtures led to increased flowability and delayed hydration compared to finer ones. Steel slag powders presented the most significant plasticizer effects, but also the largest setting delays and segregation tendency. Quartz-rich superfines reduced the setting delays caused by the superplasticizers. In summary, both superplasticizers were effective in improving flow properties, but the high-charge PCE was effective in preventing segregation in pastes containing mineral admixtures coarser and heavier than cement.

Enhancing the eco-efficiency of concrete using engineered recycled mineral admixtures and recycled aggregates

Non-conventional densely packed concrete mixtures are proposed and evaluated in this paper using engineered recycled mineral admixtures and recycled aggregates obtained from steel slag, quartz mining tailings, and quartzite mining tailings. High fines content sand-concretes containing coarser- and finer-than-cement recycled powders were designed to obtain blends with broader particle-size ranges and improved packing density. As a result, compressive strength up to 99 MPa, cement intensity up to 2.33 kg/m³/MPa, and consumption of recycled material up to 95 vol% were obtained. Compressive strengths up to 66 MPa and cement intensity up to 2.34 kg/m³/MPa were also obtained with the addition of coarse aggregates to such sand-concrete mixtures, with consumption of recycled material up to 96.5%. The results launch new insights on the role of recycled admixtures and aggregates on the mixture design of cement-based composites regarding efficiency improvement and technological performance.

The effects of organic amendments on heavy metals bioavailability in mine impacted soil and associated human health risk

Accumulation of heavy metals in soil and agricultural products is of great concern as it not only affects crop growth and yield but also food safety and marketability. The aim of the present study was to determine the effects of different organic amendments on toxic metal uptake by radish (Raphanus sativus L.). A pot experiment was conducted using garden soil as control and the contaminated soil collected from mine dumps of chromite mine, soap stone mine, quartz mine, manganese mine. Garden and mine impacted soil was mixed with vermicompost, leaf compost and spent mushroom compost at 1:1:1 ratio following a completely randomized block design. Results indicated that highest Cd (2.62 mg kg−1) and Cr (13.6 mg kg−1) concentration was reported in chromite mine soil, while Pb (23.3 mg kg−1) and Mn (59.2 mg kg−1) concentration as recorded in soap stone mine and manganese mine impacted soil, respectively. All the growth parameters and heavy metal concentrations were significantly affected by the amendments. The pollution load assessment of different mining soil revealed that the soil was moderately to considerably polluted with various heavy metals, particularly Cd with CF, Igeo and Eri values of 2.26, 0.45 and 67.68, respectively. Mining soils with high amount of heavy metals negatively affected radish growth and yield, while organic fertilizers amendment reduced heavy metals availability, increased radish growth and minimized human health risk. Among selected organic fertilizers vermicompost was more effective and reduced Cd, Cr, Pb and Mn uptake by 32.5, 50.25, 44.50 and 42.25 %, respectively, and improved radish growth, food quality and reduce human-health risk.

Collector's Note: Colorado Quartz Mine Does It Again, Mariposa County, California

Collector's Note: Colorado Quartz Mine Does It Again, Mariposa County, California

More eco-efficient concrete: An approach on optimization in the production and use of waste-based supplementary cementing materials

Abstract This paper presents a study that includes increase in clinker replacement and waste consumption in cement-based composites. Techniques for performance optimization of waste-based supplementary cementing materials in densely packed matrices using basic oxygen furnace slag, iron ore tailings from a tailings dam, quartz mining tailings and quartzite mining tailings were evaluated. Powders with different particle size ranges were produced and characterized. A highly-packed sand-concrete reference mix was designed and six different mixtures with 10−60 vol% partial cement replacement were evaluated. The high binder efficiencies observed and physical-mechanical performances evidence the effectiveness of the proposal, expanding the concept of low-cost supplementary cementing materials and broadening the range of residual materials suitable for use in cement-based composites.

Characterization and Beneficiation of Gold Mining By-products as Source of High-Quality Silica for High Technical Applications; Response Surface Studies and Optimization

This paper aims to evaluate and upgrade the quality of quartz mining by-products through acid leaching process. The quartz samples were collected as gold mine by-products from El Sid- Fawakhir gold mine, Qift-Quseir, Eastern Desert, Egypt and characterized using XRF and polarized transmitted optical microscope. The present magnetic mineral impurities were detected using Frantz Isodynamic Tester. Suitability of acid leaching utilizing oxalic acid as an efficient technique for considerable reduction of the associated impurities was evaluated based on Response Surface methodology and face centered central composite design (CCD). The quartz sample was classified as low-quality quartz with low silica content (99.3%) which can’t match the requirements of wide range of applications. The main detected impurities are muscovite, biotite, sericite, pyrite and iron oxide. The present magnetic impurities represent about 2.72% of the total sample. The leaching process at the optimum conditions of temperature, time and oxalic acid concentration removes $\sim $ 36% of the iron. This associated with a clear reduction of other magnetic impurities and noticeable enhancing in the silica content to about 99.56%. Magnetic purification followed by oxalic acid leaching for the quartz samples give better results as the iron content was reduced to about 0.001% and the silica content increased to about 99.9% which match the specifications of most of the typical high technical applications.

Relationship of Technological Properties with Dynamic Recrystallization of Quartz on the Example of Objects of the Karelian-Kola Region

Despite the significant reserves of quartz raw materials, there is a deficit of high purity quartz. It is due to the strict technical requirements imposed by standards for this type of raw materials and technological properties of quartz, which are determined by the features of the crystal structure. The crystalline structure is of particular importance for the technological properties of quartz, since such important characteristics as the limit of raw material enrichment, dissolution rate in acid, melting point of quartz, etc., are determined. The formation of the crystal structure of quartz under natural conditions is associated with the successive dynamic recrystallization of the mineral. The degree of dynamic recrystallization of quartz reflects the distribution of dispersed impurities. If it is weakly manifested, the dispersed impurities are not displaced from one zone to another, and all quartz microblocks contain approximately the same concentration. In this case, more or less uniform dissolution of various regions of quartz is observed, and the pattern of distribution of submicroscopic inhomogeneities is monotonic. If intensive dynamic recrystallization of quartz takes place, then it causes a significant redistribution of the scattered impurities. Then the treatment in HF leads to the appearance of a contrast pattern of the distribution of submicroscopic inhomogeneities. The details of the crystal structure of quartz in this work were investigated by the electron paramagnetic resonance (EPR) method using the ER-420 “Bruker” spectrometer. In the selected samples of quartz, the concentrations of isomorphic impurities Al and Ti were measured, and the degree of crystallinity D of the mineral was estimated from the EPR spectra of each of them. Thus, the technological properties of quartz are determined by various geological processes. The results of the studies show that when evaluating the prospects of quartz raw materials, it is necessary to take into account the staged dynamic dynamical recrystallization of quartz in natural conditions. This factor can play both a positive and a negative role at various stages of mineral formation. Its influence is reflected in the state of the crystal structure of quartz, which should be taken into account when developing effective technologies for its enrichment. The intermediate stage of dynamic recrystallization corresponding to the end of the second stage-the beginning of the third stage of quartz recrystallization-is optimal for the formation of high-purity quartz. When choosing a site for the first-stage quartz mining at large deposits in the Karelian-Kola region, one should be guided by the stage of dynamic recrystallization.

Физическое моделирование взрывной отбойки высокоценного кварца

Физическое моделирование взрывной отбойки высокоценного кварца

Quality characteristics of quartz in Xuan Tam mine, Xuan Loc district, Dong Nai province and applications of the production of the “quartz stone” artificial stone

This article presents a summary of the geological characteristics of the quartz of Xuan Tam mine, Xuan Loc district, Dong Nai province and the results of research on the quality and the mineral technological characteristics of this mine.The data gained from the research indicated that the quartz mine in Xuan Tam area had a high to average temperature of hydrothermal origin and associated with granitoid intrusive formations in the area. This quartz mine possessed minerals vein, and penetrate to the sedimentary formations of the Tra My form. The quality and the technological properties of quartz in the mineral body are suitable for applications such as a material of “quartz stone” artificial stone that uses color, and it could replace a part for the imported material. It’s necessary to have further research, especially on technological characteristics in order to orient the exploitation and the efficient use of the quartz mineral mine Xuan Tam, as well as other areas in the territory of South Vietnam.

Study on Optimization Quartz Mine for Removal Gas-Liquid Inclusions in Quartz Sand under Microwave and Acid Corrosion

Using Gas Chromatography and Fourier Transform Infrared Spectroscopy (FT-IR), the content of metal impurity element and gas-liquid inclusions in natural crystal and ordinary silica mine of different mining area had been studied. The characteristics of silica mine which was suitable for microwave-acid etching process to remove gas fluid inclusion in quartz sand had been discussed.Our results showed that the silica mine which had low content of impurity, less content of gas-fluid inclusion and high water filling degree was suitable for the microwave-acid etching process to remove gas-liquid inclusion in quartz sand; the content of metal element impurities in quartz sand from Madagascar was nearly close to the primary natural crystal, had less content of gas-fluid inclusion and high water filling degree, and was suitable for the microwave-acid etching process to remove.

Recycling of waste products in the induction of biofilms to remediate the visual impact generated by quartz mining

The present study was undertaken to investigate the viability of the use of two waste products, cheese whey and composted organic waste, as nutrient sources in the induction of biological films on quartz surfaces, with the final aim of reducing the visual impact generated by quartz mining. Experiments were carried in laboratory in which quartz samples were colonized with microorganisms (mainly cyanobacteria) forming biofilms. Previous studies have shown that a nutritional supplement must be added for good development of biofilms and, therefore, application of the two waste products was compared with application of the chemical nutrient medium on which these types of microorganisms are usually cultivated. Both products provided better results than the culture medium, in terms of the speed of formation of the biofilm, faster with the waste products, and the degree of cover of the brilliant white colour of the quartz, better masked by the biofilms formed when the waste products were applied as a darker biofilm was obtained.

Methodological aspects of the induction of biofilms for remediation of the visual impact generated by quartz mining

The opening up of mine faces causes severe alteration to the environment that must be remedied. In the case of quartz mines, the bright white colour of the mineral gives rise to a significant impact that is visible for long distances. New techniques to correct this visual impact, based on the induction of biofilms on the faces, have recently been developed in an attempt to imitate natural effects that mask the impact. Although techniques have been applied successfully in the laboratory, they must be optimized to ensure their success in the field. In the present study, the results of a randomized factorial experiment indicated that although the biofilms adhere to the faces naturally, without the use of adhesives, continued development of the film depends to a large extent on the input of nutrients. Water must also be provided with nutritional supplement to maintain the required level of moisture.