Pyrite Cinder Research Articles

Recovery of Cu, Co, and Fe from Pyrite Cinder Based on Mineral Phase Reconstruction.

Pyrite cinder (PyC) containing polymetallics is difficult to use due to the low grade of metals and complex mineral phase composition, the low reutilized rate of which causes the wastage of resources. In this paper, a novel approach based on mineral phase reconstruction was proposed to recover Cu, Co, and Fe from PyC. A feasible reduction roasting process was developed for mineral phase reconstruction, followed by leaching with sulfuric acid to recover Cu and Co; finally, the leaching residue was separated by a magnetic tube to recover Fe. The maximum copper and cobalt extract rates of 86.15 and 79.61% were achieved respectively under the optimized conditions of reduction roasting for 30 min at 550 °C and 30% CO/N2 volume fraction, followed by leaching for 4 h at a liquid-solid ratio of 4:1 (mL/g), a mass concentration of 160 g/L sulfuric acid, and a temperature of 70 °C. The iron concentrate can be obtained with 63.08% Fe grade and 98.91% recovery rate by magnetic separation at a magnetic field strength of 28.26 kA/m. The mechanism analysis results of mineral phase reconstruction revealed that the primary copper sulfide in PyC was transformed into free copper oxide, combined copper oxide, and secondary copper sulfide without changing the valence state of copper by reduction roasting, resulting in a higher extraction rate of copper. Meanwhile, cobaltosic oxide and cobalt ferrite in PyC were transformed into cobalt sulfate and cobalt sulfide with the reduction of Co(III) to Co(II), improving the extraction rate of cobalt.

Manufacturing of Fe/C micro-electrolysis materials with the pyrite cinder towards the degradation of high-concentration organic wastewater

Large volumes of pyrite cinder (PyC) was produced about 12 million tons/a in China but the utilization rate is low. In this work, an innovate method has been developed to utilize the hazardous pyrite cinder for manufacturing Fe/C micro-electrolysis materials, which can be used to degrade high-concentration organic wastewater. The effects of preparation conditions on degradation performance of materials were investigated based on the removal rate of chemical oxygen demand (COD) from the simulated methylene blue wastewater containing 500 mg/L initial COD. The results demonstrated that the impressive COD degradation of ICMEM reached 94.37 % within 120 min under manufacturing at 950℃ for 75 min via carbothermal reduction of PyC pellets with 15 % carbon addition. The X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS) and chemical phase were used to reveal that the formation of Fe0 and Cu0 resulted in the creation of numerous galvanic cells with carbon and effectively facilitating the degradation of methylene blue. This research presents an innovative approach towards cost-effective PyC recycling and he degradation of methylene blue in wastewater.

Assessing an Abandoned Pyrite Cinder Deposit in Southeast Spain with Electrical Resistivity Tomography: A Case Study

Industrial activities have historically generated significant quantities of by-products, including pyrite cinders, a residue produced during the synthesis of sulphuric acid. This study presents a multidisciplinary approach to characterise an abandoned pyrite cinder deposit. Combining geophysical (electrical resistivity tomography—ERT), geochemical, and statistical methods, we assess the physicochemical properties of the deposit and its environmental implications. Our findings reveal the presence of heavy metals, with lead (7017.5 mg.kg−1) being the most concentrated element on the surface of the deposit, exceeding local legal thresholds by more than 163 times, posing environmental risks and inhibiting vegetation growth. Subsurface characterisation indicates a decreasing concentration trend of metals with depth, alongside variations in pH and electrical conductivity. Clustering analysis identifies groups of similar behaviours between resistivity, the most abundant heavy metals, and other variables, providing valuable insights into the complex interplay within the deposit. Our study underscores the importance of integrated approaches in assessing and managing hazardous waste sites, with implications for environmental remediation strategies.

Production of effective materials on the basis of sulfuric acid industry wastes

Introduction. Solving the urgent problem of the production of special concretes using certain varieties of substandard natural raw materials and a number of industrial wastes will support introducing the principles of resource saving and improving the technological features of production.Aim. To make a comprehensive assessment of the impact of sulfuric acid production wastes and substandard natural clay raw materials on the production of high-quality and durable concretes for special purposes.Materials and methods. Easily fusible clay rocks serve as a raw material for the production of expanded clay gravel. Organic (solar oil) and ferruginous (pyrite cinders) additives were used. X-ray analysis was carried out to determine the crystalline phases in the clay of the Nikolskoe oil-field, in the resulting expanded clay gravel, as well as to analyze the factory bulk samples of pyrite cinders. A tubular electric furnace was used for firing in a two-stage mode of 700 and 1100 °C to obtain high-strength expanded clay gravel under laboratory conditions. The research involved studying parameters of phosphate binder formation and properties of iron phosphate concrete based on H3PO4 and sulfuric acid industry wastes – pyrite cinders.Results. It was found that Nikolskoye field clay forms a good raw material for the production of high-strength heavy expanded clay gravel with a strength of up to 550 kg/cm2, water absorption of 1.5 % and resistance to aggressive environments, thereby making it suitable for manufacturing special concretes. The results obtained specify the test methods and technical requirements, control methods and product acceptance rules, thus improving the quality and durability of the concretes considered.Conclusions. The investigated non-bloating clay can be used with organic and ferruginous additives to obtain high-strength expanded clay gravel for the manufacture of structural concretes. A mixed iron phosphate binder serves for producing heat-resistant concretes for linings of melting and casting units in non-ferrous metallurgy with high resistance and durability.

Study on Plant-blanket to reduce heavy metal migration caused by precipitation and to improve the soil environment of pyritic tailings

The increasing demand for mineral resources due to industrial development has led to significant tailings pollution during the mineral extraction process. In the southwestern region of China, a large amount of pyritic tailings containing pyrite cinder easily leaches heavy metals and other pollutants when exposed to precipitation, resulting in widespread soil contamination. Effective remediation methods are urgently needed to address this issue. This study utilized naturally occurring Plant-blanket formed by the symbiosis of moss and herbaceous plants on pyritic tailings as restoration material. Through leaching experiments and staining tracer techniques, the study investigated the ability of Plant-blanket to reduce the migration of heavy metals from pyrite cinder to soil under the influence of precipitation and its role in improving the soil environment. The results showed that within 12 h, the Plant-blanket could absorb water equivalent to 206.9 % of its own weight and had good water retention ability. It reduced the stained area ratio of soil horizontal and vertical profiles after precipitation leaching by a maximum of 76.08 % and 46.41 %, respectively, and improved the pH, cation exchange capacity (CEC), bulk density, and water content of soil at different depths. In addition, after being covered by Plant-blanket, the migration of Cd and Cu was reduced by a maximum of 44.35 % and 55.77 % respectively, and it increased the diversity and abundance of bacterial communities, promoting the recovery of soil microbial ecological functions. These findings indicate that Plant-blanket can regulate water and improve soil environment, and has certain control ability on the migration of Cd and Cu produced by pyritic tailings. Meanwhile, Plant-blanket plays an important role in improving the soil environment in mining areas and promoting ecosystem restoration, providing valuable reference for further exploration of ecological restoration of tailings.

АНАЛИЗ ПРОЧНОСТНЫХ ХАРАКТЕРИСТИК И ВАРИАТИВНОГО ИСПОЛНЕНИЯ ЭЛЕМЕНТОВ ГИДРОЦИКЛОНА ДЛЯ СОВЕРШЕНСТВОВАНИЯ ЕГО КОНСТРУКЦИИ

Promising directions for improving the efficiency of pyrite cinder separation for their further use in the production of Portland cement are considered. The object of the study is a digital model of a modified hydrocyclone with a separation area in the working area, which allows for precise separation of particles. The purpose of the study is to identify the appropriate design parameters of a modified hydrocyclone during strength calculations and variable execution of its model. Computer modeling of hydrodynamic processes during the creation of new equipment allows for an analysis of its operability, strength calculations and variable design of the device at the design stage, which is currently relevant. The changes in the efficiency of particle separation in a modified hydrocyclone depending on the varying geometric parameters in the working area of the apparatus are considered. The influence of the thickness of the sheets of the parts of the separation area has been studied and important aspects affecting the operating conditions of the device have been identified. Optimization of the geometry of the holes in the separating area of the hydrocyclone is proposed in order to capture more particles of the required fraction (size 60 microns or less). The resulting modified hydrocyclone design based on HCC-360-10 has significant application potential in various industries, including ore dressing, cement, petroleum, chemical industry and energy. The use of such a design can lead to a significant reduction in energy consumption, increased productivity and improved product quality. A method for static calculation of the strength of the separation region of a modified hydrocyclone using the finite element method in a CAD/CAE system is presented.

A Novel Approach for Comprehensive Utilization by Leaching Pyrite Cinder with Titanium Dioxide Waste Acid by Response Surface Methodology.

Comprehensive utilization of two industrial wastes by leaching pyrite cinder with titanium dioxide waste acid was proposed by using response surface methodology of the Box-Behnken design method. The effects of leaching conditions such as leaching temperature, leaching time, and waste acid/pyrite cinder ratio on the leaching yield were examined. The prediction model including the leaching variables with a good fitting result was established to predict the leaching yield or optimize the leaching variable values. The regression equation model was significant and reliable with an actual correlation coefficient R2 of 0.9856. The leaching conditions greatly affected the leaching rate, reaction equilibrium, solubility of the acid decomposed substances, and the common ion effects, influenced the leaching process, and finally improved the leaching yield. The variables such as leaching temperature and waste acid/pyrite cinder ratio had the greatest collaborative interactions, and the effects of the waste acid/pyrite cinder ratio were larger than the other two. The verification experiments confirmed that the leaching yield values could be achieved at 82.68 % under the optimal conditions.

Investigations on oxygen carriers derived from natural ores or industrial solid wastes for chemical looping hydrogen generation using biomass pyrolysis gas

Chemical looping process based on multiple-step redox reactions of oxygen carriers (OCs) holds great promise for producing high purity hydrogen with inherent CO2 separation, however, there is a challenge to prepare environmental-friendly OCs with low-cost. Herein, a series of natural ores and industrial solid wastes were screened and made into Fe-based OCs for chemical looping hydrogen generation (CLHG). The results show that OCs prepared by pyrite cinder (OC-PC) feature 94.8% biomass pyrolysis gas (BPG) conversion and 94.5% CO2 concentration in OCs reduction stage. In hydrogen production stage, OC-PC achieves maximum H2 yield, 3.04 mmol g−1, which is 2∼9 times high than other OCs. The highest H2 purity is approximately 99.99%. Long term testing results indicate that OC-PC has excellent stable activity and anti-sinter ability. OCs prepared by red mud correspond to better BPG conversion (96.0%), however, the H2 yield (0.83 mmol g−1) is much lower than that of OC-PC. For OCs prepared from natural ores, they show unsatisfactory H2 production and BPG conversion compared with OC-PC. OCs prepared by ilmenite are with low specific surface area which restrains the heterogeneous reaction. The content of metal element (Mg, K, Ca) also influences the behavior of OC, which is beneficial for the fuel conversion. Moreover, the distribution of inert, anti-coking ability, oxygen vacancy also influence the sinter, H2 purity and H2 yield. Comprehensively evaluating the OCs performance, pyrite cinder is considered to be the most suitable OC raw material for CLHG.

Recovery of Valuable Metals from Iron-Rich Pyrite Cinder by Chlorination-Volatilization Method

Recovery of Valuable Metals from Iron-Rich Pyrite Cinder by Chlorination-Volatilization Method

ПИРИТНЫЕ ОГАРКИ КАК НАПОЛНИТЕЛЬ КОМПОЗИЦИОННОГО МАТЕРИАЛА НА ОСНОВЕ БУТАДИЕН-СТИРОЛЬНОГО КАУЧУКА

Currently, recycling waste from various types of production, as well as finding the possibility of reusing it, is a very relevant topic. In the modern world, rubbers make a tremendous contribution to the development of the industrial sector. In order to study the possibility of using pyrite cinders as a filler for a rubber mixture based on styrene-butadiene rubber, the elastic-strength and rheological characteristics of the finished composite mixtures were studied, and the contact angle of wetting was determined to assess the interaction of the compositions with other materials. It was established that there was no influence of pyrite cinders on the nature of the surface of the rubber mixture. The dependence of the storage modulus on the deformation amplitude for different types of fillers has been established, which makes it possible to evaluate the qualitative and quantitative distribution of the filler in the polymer and the interaction of the polymer and the filler. It was revealed that pyrite cinders and chalk have a weak interaction with the polymer, from which it follows that they behave as a non-reinforcing filler, but their introduction into the polymer matrix does not deteriorate the elastic-strength properties of the rubber. The dependence of stress on deformation for mixtures with different types of fillers has been established. It was established that in terms of technological characteristics, no deviations in the material from the generally accepted patterns of introducing fillers into the polymer matrix were found. The values remain at the level of unfilled rubber and rubber filled with technical chalk. The general complex of properties of the composition based on styrene-butadiene rubber with pyrite cinders allows it to be recommended, after modification, for use in the production technology of rubber products.

Recovery of iron from pyrite cinder by suspension magnetization roasting-magnetic separation method: Process optimization and mechanism study

Pyrite cinder (PyC) is an iron-enriched tailing.Suspension magnetization roasting(SMR) technology can convert hematite into magnetite, the magnetic properties of the product have been improved, and then through the magnetic separation to complete the separation of magnetite and gangue. SMR consumes less energy than the direct reduction process to obtain Fe(M).SMR-magnetic separation is utilized to effectively exploit the iron in PyC. The results showed that the raw ore for PyC has an iron grade of 56.47%, and after SMR-magnetic separation, magnetic concentrate with an iron grade of 63.24% and an iron recovery of 95.05% could be achieved under conditions of a roasting temperature of 480°C, a reductant concentration of 30% (CO: H2 = 1:3), a roasting time of 20min, 1200Oe magnetic field intensity, and a finesse of grinding content of -0.038mm 80%. The analyses of the process mechanism were performed using X-ray diffraction (XRD), vibrating sample magnetometer (VSM), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy as well as fully automatic specific surface and porosity analyzer BET. It was revealed that the transformation of hematite to magnetite took place during the suspension magnetization roasting process, which also contributed to the generation of cracks and pores that led to the increase of specific surface area, total pore volume and average pore diameter.

Construction of a porous pyrite cinder-supported Mn-doped BiFeO3 composite photocatalyst: Confined-space strategy, structure, and visible-light catalytic degradation toward ciprofloxacin

A series of novel confined visible-light catalysts, namely, Mn-doped BiFeO3 (MBFO) composite photocatalyst anchored on porous residue pyrite cinder (PR-PyC) after partial Fe extraction (PR-PyC/MBFO-φ, φ refers to the doped amount of Mn), was successfully constructed via confined-space strategy using the Fe extracted from PyC as Fe source for BiFeO3 (BFO) and the PR-PyC as the template and structure regulator for MBFO generation. The resulting PR-PyC/MBFO-5% is composed of relatively uniform nanoparticles anchored in the channels of PR-PyC matrix and interparticle interstices and has a specific surface area of 14.18 m2/g, an average pore size of 37.76 nm, and a pore volume 0.13 cm3/g. It has a type-II heterojunction with a band gap energy (Eg) of 1.95 eV and exhibits high visible-light catalytic degradation activity toward ciprofloxacin (CIP) and excellent recyclability. The CIP degradation rate of PR-PyC/MBFO-5% reached 96.41% with an apparent reaction rate constant kapp of 0.0265 min−1 under visible-light irradiation for 120 min, and the corresponding mineralization rate reached 77.42%. The active species produced during photocatalysis were h+ and •OH, in which h+ plays a major role. The doping of 5% Mn can effectively regulate the energy band structure and heterojunction type and the use of an appropriate amount of PR-PyC can effectively guide and regulate the structure and morphology of the as-prepared catalyst. This study presents an effective confined-space strategy for fabricating innovative high-efficiency photocatalysts for antibiotic degradation, thereby paving the way for the valuable resource utilization of PyC.

Performance and mechanism of heterogeneous catalyst prepared from pyrite cinder for tetracycline hydrochloride degradation

Performance and mechanism of heterogeneous catalyst prepared from pyrite cinder for tetracycline hydrochloride degradation

Comprehensive Utilization of Pyrite Concentrate Pyrolysis Slag by Oxygen Pressure Leaching

The preparation of high-purity sulfur and pyrrhotite by pyrolysis holds great potential to realize the high-value utilization of pyrite concentrate (FeS2), i.e., a by-product during the flotation of sulfide ore. In this study, the pyrrhotite obtained from the pyrolysis of pyrite concentrate was taken as the study object, and the effects of acid types, initial acidity, leaching time, leaching temperature, oxygen pressure, and liquid-to-solid ratio on the leaching behavior of pyrrhotite under oxygen pressure, were explored. The results show that elemental sulfur and hematite-based iron residue can be obtained by oxygen pressure leaching of pyrrhotite. It is found that the optimal experimental conditions for pyrrhotite oxygen pressure leaching are hydrochloric acid with 0.8 mol/L of initial acidity, 5 h of leaching time, 0.8 MPa of oxygen partial pressure, and 9:1 of liquid to solid ratio at 150 °C; moreover, the yield of sulfur reached 88.37%. Under optimal conditions, the leaching ratios of Fe, Pb, and Zn were 19.8%, 92.25%, and 99.11%, respectively. The sieved leaching residue was roasted at a low temperature of 500 °C, where the grade of Fe in the obtained hematite iron powder was 61.46%, and the grades of Pb, Zn, and S were 0.082%, 0.024%, and 0.1%. Clearly, the results meet well with the standard of the first grade of pyrite cinder, and this process realizes the comprehensive recovery of Fe and S resources in pyrolysis slag, which provides a superb technical route for the high-value utilization of pyrite concentrate.

On the Question of the Complex Processing of Pyrite Cinders

A complex processing variant for pyrite cinders, i.e., the technogenic waste generated in the production of sulfuric acid, was proposed. This method provided preliminary chemical activation of the initial raw materials that comprised thermal treatment with a sodium bicarbonate solution and resulted in structural and phase changes of separate minerals. Due to chemical activation, it was possible to separate the nonferrous metals into separate products (in addition to the partial extraction of iron) and then concentrate the noble metals in the residue. The noble metals were then able to be extracted through a leaching process with a complex reagent based on sulfur compounds and subsequent cementation with zinc dust. The developed method, unlike pyrometallurgical methods, is less energy-consuming and more easily implemented than the known hydrometallurgical variants, enabling the separation of nonferrous metals and the partial separation of iron into separate middlings at the first stage. Noble metals are concentrated in the residue and extracted from it.

Pyrite Cinder as an Effective Fenton-like Catalyst for the Degradation of Reactive Azo Dye: Effects of Process Parameters and Complete Effluent Characterization

This research investigates the potential use of pyrite cinder (PC) as an efficient Fenton-like catalyst for the removal of the reactive azo dye Reactive Red 120 (RR120) from aqueous solutions. The characterization of its PC structure and composition confirmed its great potential to act as catalytic iron source in a heterogeneous Fenton system. Dye removal optimization was performed in terms of PC dosage (0.4–8 g/L), H2O2 concentration (2–25 mM), pH value (2–4.6), initial dye concentration (50–200 mg/L), and mixing time. The highest decolorization efficiency (92%) was achieved after a reaction time of 480 min under following conditions: RR120 = 50 mg/L, PC = 4 g/L, H2O2 = 10 mM, and pH = 3. After decolorization, an extensive analysis of the generated effluent was performed regarding metal leaching, mineralization, toxicity, and degradation product formation. The metal leaching indicated the necessity for a pH increase in order to remove the settled metal hydroxides. The mineralization efficiency was satisfactory, reaching 85% and 62% of the COD and TOC removal, respectively. The respirometry measurements and bioluminescence tests indicated the detoxification of the treated solution. The absorption spectra and GC/MS analysis confirmed the changes in the molecular structure in the form of the destruction of the azo bond, with a simpler aromatic and aliphatic intermediates formation. This study provides an effective method for removing azo dye in polluted water by employing waste tailings as alternative Fenton-like catalysts, while also using waste tailings as the secondary resource.

Extraction of Noble Metals from Pyrite Cinders

When obtaining sulfuric acid from pyrite concentrates, a significant amount of waste is generated in the form of pyrite cinders that require disposal. The methods used in processing this raw material are, as a rule, the pyrometallurgical processes of chlorination and chloride sublimation, the disadvantages of which include increased energy consumption and a lack of complexity in the extraction of valuable components. Hydrometallurgical processes are in less demand due to their multi-stage nature and complexity of execution. The method of chemical activation developed at the JSC “Institute of Metallurgy and Ore Beneficiation” makes it possible to isolate iron and non-ferrous metals into separate, middling products and to concentrate noble metals in the cake at the first stage. Physical and chemical studies of the cake found that its basis comprises iron compounds. The silver in the cake is associated with pyrite, while the gold is associated with hematite; it is also possible to find gold in the form of AuCl3. The content of gold in the cake is 1.5 g/t, and the silver content is 17.7 g/t. Based on physical and chemical studies and data from the literature, various versions of the hydrochlorination method are proposed to open the cake.

Mathematical modeling of sulfuric acid leaching of pyrite cinders after preliminary chemical activation

Pyrite cinders, waste products of pyrite concentrate processing by firing to produce sulfuric acid, can serve as raw materials for the extraction of precious, ferrous, and non-ferrous metals. The paper considers the possibilities of obtaining non-ferrous metal concentrate from pyrite cinders by sulfuric acid leaching. This operation is one of the stages in the integrated technology. To increase the extraction of non-ferrous metals during leaching, the method of preliminary chemical activation was used. Chemical activation was carried out in a solution containing 40-120 g/dm3 NaНCO3 at temperatures of 90-230 ° C and a duration of 30-300 minutes. Sulfuric acid leaching of pyrite cinder after activation was carried out in H2SO4 solutions with a concentration of 5-20 % at a temperature of 60 ° C, duration of 30 minutes, and pulp density of 33 %. To determine the optimal conditions for the sulfuric acid leaching of pyrite cinders, a mathematical planning method was used, which allows to assess with a high degree of reliability the influence of the main factors (temperature, pulp density, the concentration of the solution NaHCO3 and duration) and predict an increase in the efficiency of the process by analyzing the numerical values of the regression equations. As a result of sulfuric acid leaching of pyrite cinders after preliminary chemical activation under optimal conditions determined by a mathematical model, the extraction of iron and non-ferrous metals into a solution is 10-15% higher than without activation.

Green and short smelting process of bismuth sulphide concentrate with pyrite cinder

The traditional smelting process of bismuth sulphide concentrate faces problems of low metallic bismuth recovery, high production cost and low-concentration SO2 flue gas pollution. In this study, a clean and efficient smelting process was developed to directly extract bismuth metal from bismuthinite concentrate. The reaction mechanism and phase transformation laws were confirmed by thermodynamic simulation calculation, TG-MS thermal analysis and phase characterization. Firstly, Fe2O3 and Fe3O4 interacted with Bi2S3 to form Bi2O3. The intermediate Bi2O3 was then reduced into metallic Bi, and the element S was fixed as FeS. Results of the smelting simulation experiments showed that 89.25% metallic Bi was recovered. About 38.17% Pb, 33.92% Cu, and 83.98% Ag were enriched in crude bismuth, and 96.37% S was fixed in the matte as raw material for resource recovery and energy utilisation.

Investigation of the redox performance of pyrite cinder calcined at different temperature in chemical looping combustion

As an industrial solid waste, pyrite cinder exhibited excellent reactivity and cycle stability in chemical looping combustion. Prior to the experiment, oxygen carriers often experienced a high temperature calcination process to stabilize the physico-chemical properties, which presented significant influence on the redox performance of oxygen carriers. However, the effect of calcination temperature on the cyclic reaction performance of pyrite cinder has not been studied in detail. In this work, the effect of calcination temperature on the redox activity and attrition characteristic of pyrite cinder were studied in a fluidized-bed reactor using CH 4 as fuel. A series of pyrite cinder samples were prepared by controlling the calcination temperature. The redox activity and attrition rate of the obtained pyrite cinder samples were investigated deeply. The results showed that calcination temperature displayed significant impact on the redox performance of pyrite cinder. Considering CH 4 conversion (80%–85%) and attrition resistance, the pyrite cinder calcined at 1050 °C presented excellent redox properties. In the whole experiment process, the CO 2 selectivity of the pyrite cinder samples were not affected by the calcination temperature and were still close to 100%. The results can provide reference for optimizing the calcination temperature of pyrite cinder during chemical looping process.