Industrial technologies for processing tungsten concentrates using soda roasting or autoclave leaching are based on the production of alkaline sodium tungstate solutions that contain impurities such as silicon, phosphorus, arsenic, and others. The purification of these solutions from impurities requires the neutralization of excess soda or alkali with inorganic acids, which leads to the formation of chloride and sulfate effluents that are subsequently discharged into waste repositories. An analysis was carried out on existing methods for the production and processing of sodium tungstate solutions using HNO₃ and NH₃, as well as extraction and sorption techniques involving anion exchange resins. Currently, processes such as nanofiltration, reverse osmosis, and electrodialysis are being applied for water purification and the treatment of sulfate and chloride effluents. These processes employ various types of industrially manufactured membranes. For the purpose of electrodialysis, a two-compartment electrodialyzer setup was employed using cation-exchange membranes of the MK-40 (Russia) and EDC1R (China) types. The composition and structure of sodium tungstate, used as the starting reagents, were analyzed. Based on experiments conducted on a laboratory-scale unit with continuous circulation of the catholyte and anolyte, dependencies of various parameters on current density and process duration were established. Stepwise changes in the anolyte pH were recorded, indirectly confirming changes in the composition of the Na₂WO₄ solution, including the formation of polytungstates of variable composition and the production of H₂WO₄ via electrodialysis at pH < 2. The resulting tungstic acid solutions were also analyzed. The conducted studies on the processing of sodium tungstate solutions using electrodialysis made it possible to obtain alkaline solutions and tungstic acid at a current density of 500–1500 A/m², without the use of acid for neutralization. Yellow tungstic acid was obtained from the tungstic acid solution by evaporation.

Focuses on the processing of tungsten raw materials through various operations, including sintering, leaching, purification, and the production of technical tungstic acid. Modern research aims to enhance these processes, particularly the sintering of wolframite concentrates with alkali metal compounds and the leaching of concentrates and cakes. Experiments revealed that reactions between tungsten minerals and sodium carbonate from Akchatau ores commence at temperatures above 520–550 °C, intensifying between 750 and 850 °C. The concentrates were sintered at 750, 800, and 850 °C with a sodium carbonate excess coefficient of 1.05 to 1.2 to evaluate the effect on sodium tungstate extraction. Water leaching was conducted under a probabilistic–deterministic experimental design, analyzing five factors at four levels. Tungsten extraction was assessed based on solution density and the composition of the insoluble residue. Data processing established polynomial trends for tungsten trioxide extraction, and a material balance for sinter leaching was calculated from experiments using 100 g samples with a liquid-to-solid ratio of 2:1. The findings can be applied to improve tungsten processing technologies.

The study focuses on the processing of tungsten raw materials through various operations, including sintering, leach-ing, purification, and the production of technical tungstic acid. Modern research aims to enhance these processes, particularly the sintering of wolframite concentrates with alkali metal compounds and the leaching of concentrates and cakes. Experiments revealed that reactions between tungsten minerals and soda from Akchatau ores commence at temperatures above 520-550 °C, intensifying between 750-850 °C. The concentrates were sintered at 750, 800, and 850 °C with a soda excess coefficient of 1.05 to 1.2 to evaluate the effect on sodium tungstate extraction. Water leaching was conducted under a prob-abilistic-deterministic experimental design, analyzing five factors at four levels. The tungsten extraction was assessed based on solution density and the composition of the insoluble residue. Data processing established polynomial trends for tungsten trioxide extraction, and a material balance for sinter leaching was calculated from experiments using 100 g samples with a liquid-to-solid ratio of 2:1. The findings can be applied to improve tungsten processing technologies.

Дана характеристика отвальным медным шлакам, рассчитан их рациональный состав. Для эффективной переработки подобных шлаков предложено применение процесса выщелачивания растворами серной кислоты, не требующего затрат тепловой энергии извне, вследствие экзотермичности протекающих реакций. Выполнен расчет термодинамических характеристик реакций, возможных при выщелачивании отвальных медных шлаков растворами серной кислоты. Проведен анализ фазового равновесия процесса выщелачивания шлака при различных расходах серной кислоты, оценено влияние температуры на изменение состава фаз, построены диаграммы фазового равновесия. Выполнены исследования по сернокислотному выщелачиванию отвальных медных шлаков при комнатной температуре и при 80 °С. Выявлены проблемы сгущения и фильтрования пульпы после выщелачивания, связанные с образованием кремниевой кислоты Үйінді мыс шлактарына сипаттама беріліп, олардың рационалды құрамы есептелді. Мұндай шлактарды тиімді өңдеу үшін жүретін реакциялардың экзотермиялық болуына байланысты жылу энергиясының сырттан шығынын қажет етпейтін күкірт қышқылының ерітінділерімен шаймалау процесін қолдану ұсынылады. Үйінді мыс шлактарын күкірт қышқылының ерітінділерімен шаймалау кезінде мүмкін болатын реакциялардың термодинамикалық көрсеткіштері есептелді. Күкірт қышқылының әр түрлі шығындарында шлакты шаймалау процесінің фазалық тепе-теңдігіне талдау жүргізіліп, температураның фазалар құрамының өзгеруіне әсері бағаланды, фазалық тепе-теңдік диаграммалары тұрғызылды. Үйінді мыс шлактарын бөлме және 80 °С температураларда күкірт қышқылымен шаймалау бойынша зерттеулер жүргізілді. Кремний қышқылының түзілуіне байланысты шаймалаудан кейін пульпаның қоюланып сүзуге кедергі жасайтыны анықталды The characteristic of dump copper slag is given, their rational composition is calculated. For the effective processing of such slags, it is proposed to use the leaching process with sulfuric acid solutions, which does not require the expenditure of heat energy from outside, due to the exothermicity of the ongoing reactions. Calculation of thermodynamic characteristics of reactions possible at leaching of waste copper slags with solutions of sulphuric acid is carried out. The phase equilibrium of the slag leaching process was analysed at different sulphuric acid flow rates and the influence of temperature on the change of phase composition was evaluated, phase equilibrium diagrams were constructed. Studies on sulfuric acid leaching of waste copper slag at room temperature and at 80 °C. Problems of pulp thickening and filtration after leaching associated with the formation of silicic acid have been identified

Lead-bearing dusts from metallurgical processes are hazardous secondary resources due to their complex composition and toxicity. At the same time, their high lead content makes them a promising feedstock for resource recovery. This study proposes an energy-efficient electrosmelting approach based on the partial substitution of sodium carbonate with calcium-rich industrial waste (sugar-industry defecate). Thermodynamic analysis and equilibrium modeling of the Pb–Sb–Fe–Na–Ca–Si–S–Cl–As system were performed in the temperature range of 200–1200 °C using Outotec HSC Chemistry. The results indicate that under equilibrium conditions approximately 90–95% of lead is concentrated in the metallic phase (~56 kg from ~60 kg in the feed), while antimony is co-recovered (~1.9–2.0 kg). The slag is dominated by calcium silicates, primarily Ca₂SiO₄, confirming the important role of CaO in slag formation and impurity fixation. Chlorine is predominantly bound as NaCl and partially as CaCl₂, while sulfur is distributed between Na₂S and Na₂SO₄. A significant portion of arsenic is predicted to be retained in the slag as calcium and sodium arsenates (Ca₃(AsO₄)₂ and Na₃AsO₄), whereas its volatilization is thermodynamically negligible under equilibrium conditions. Preliminary experimental results are generally consistent with the thermodynamic predictions and confirm the feasibility of partially replacing Na₂CO₃ with sugar-industry defecate. The proposed approach contributes to reducing the consumption of conventional fluxes and promotes the utilization of industrial waste within a circular-economy framework.