Hydrothermal Treatment of Arsenopyrite Particles with CuSO4 Solution

The nature of the hydrothermal reaction between arsenopyrite particles (FeAsS) and copper sulfate solution (CuSO4 ) was investigated in this study. The effects of temperature (443–523 K), CuSO4 (0.08–0.96 mol/L) and H2 SO4 (0.05–0.6 mol/L) concentrations, reaction time (1–120 min), stirring speed (40–100 rpm) and particle size (10–100 µm) on the FeAsS conversion were studied. The FeAsS conversion was significant at >503 K, and it is suggested that the reaction is characterized by the formation of a thin layer of metallic copper (Cu0 ) and elemental sulfur (S0 ) around the unreacted FeAsS core. The shrinking core model (SCM) was applied for describing the process kinetics, and the rate of the overall reaction was found to be controlled by product layer diffusion, while the overall process was divided into two stages: (Stage 1: mixed chemical reaction/product layer diffusion-controlled) interaction of FeAsS with CuSO4 on the mineral’s surface with the formation of Cu1+ and Fe2+ sulfates, arsenous acid, S0, and subsequent diffusion of the reagent (Cu2+ ) and products (As3+ and Fe2+ ) through the gradually forming layer of Cu0 and molten S0; (Stage 2: product layer diffusion-controlled) the subsequent interaction of CuSO4 with FeAsS resulted in the formation of a denser and less porous Cu0 and S0 layer, which complicates the countercurrent diffusion of Cu2+, Cu1+, and Fe2+ across the layer to the unreacted FeAsS core. The reaction orders with respect to CuSO4 and H2 SO4 were calculated as 0.41 and −0.45 for Stage 1 and 0.35 and −0.5 for Stage 2. The apparent activation energies of 91.67 and 56.69 kJ/mol were obtained for Stages 1 and 2, respectively. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.Funding: This work was funded by State Assignment, grant number № 075-03-2021-051/5

Effect of preliminary alkali desilication on ammonia pressure leaching of low-grade copper–silver concentrate

Ammonia leaching is a promising method for processing low-grade copper ores, especially those containing large amounts of oxidized copper. In this paper, we study the effect of Si-containing minerals on the kinetics of Cu and Ag leaching from low-grade copper concentrates. The results of experiments on the pressure leaching of the initial copper concentrate in an ammonium/ammonium-carbonate solution with oxygen as an oxidizing agent are in good agreement with the shrinking core model in the intra-diffusion mode: in this case, the activation energies were 53.50 kJ/mol for Cu and 90.35 kJ/mol for Ag. Energy-dispersive X-ray spectroscopy analysis (EDX) analysis showed that reagent diffusion to Cu-bearing minerals can be limited by aluminosilicate minerals of the gangue. The recovery rate for copper and silver increases significantly after a preliminary alkaline desilication of the concentrate, and the new shrinking core model is the most adequate, showing that the process is limited by diffusion through the product layer and interfacial diffusion. The activation energy of the process increases to 86.76 kJ/mol for Cu and 92.15 kJ/mol for Ag. Using the time-to-a-given-fraction method, it has been shown that a high activation energy is required in the later stages of the process, when the most resistant sulfide minerals of copper and silver apparently remain. © 2020 by the authors. Licensee MDPI, Basel, Switzerland.Russian Science Foundation, RSF: 0836-2020-0020Funding: This work was financially supported by the Russian Science Foundation Project No. The SEM-EDX analyses were funded by State Assignment, grant number 0836-2020-0020

Lignosulfonate, anionic surfactants and their mixtures influence on water solutions surface tension and zinc concentrate pressure leaching

The formation of elemental sulfur during sulfide concentrate pressure leaching leads to the appearance of sulfur-sulfide granules, which significantly reduces zinc dissolution rate. The solution for this problem was the use of surfactants, which prevents the negative effect of molten sulfur, avoiding the granule formation during leaching. Lignosulfonates (waste from the woodworking industry) are most often used as reagents for sulfide concentrate pressure leaching. Influence of individual and mixtures of surfactants on surface tension of aqueous solutions, zinc extraction and size-grade distribution of cakes after sulfide zinc concentrate pressure leaching. Surface tension of aqueous solutions was analyzed by stalagmometric method. Leaching was performed in titanium autoclave in presence of lignosulfonate, sodium dodecylbenzenesulfonate and sodium dodecylsulfate. Solutions after leaching were analyzed on zinc by atomic absorption spectroscopy. Size-grade analysis of cakes after leaching was carried out by laser diffraction particle size analyzer. In this work, synergetic influence was observed of anionic surfactants and lignosulfonate on decreasing of aqueous solutions surface tension. The best results were obtained when LS-SDBS mixture was used, namely in the range of sodium dodecylbenzenesulfonate concentrations 400-600 mg / l. Usage of combined surfactants allowed to achieve high rates of zinc extraction and optimal particle size of cakes after leaching. At Ls and SDBS using zinc extraction was increased from 77,2 % up to 82,8 %, with the bulk of the cake (96,7%) having a particle size of-150 μm. Combined surfactants usage (lignosulfonate and sodium dodecylbenzenesulfonate) can be recommended for applying at pressure leaching of sulfide zinc concentrates. © Published under licence by IOP Publishing Ltd.Leaching experiments and grade size analysis were conducted at the expense of the Russian Science Foundation grant (project No. 18-19-00186)

Development of the Nickel-Refining Production at Norilsk Nickel Harjavalta Oy in GMK Norilsk Nickel

Abstract: As a result of the innovative solutions found due to the joint efforts of Russian and Finnish researchers, the recovery of nonferrous and precious metals in Norilsk Nickel Harjavalta was significantly increased (%): the recovery of Ni was increased to 98.7; that of Cu, to 99.5; Pt, to 99.6; and Pd to 99.6. Simultaneously, a copper cake (one of the main commercial products) of an improved composition, namely, (%) 57–62 Cu, <3 Ni, 8–11 Fe, was produced. The arsenic content in the copper cake was decreased from 1.5–2 to 0.15–0.3%. The largest projects are as follows: stage-by stage implementation of a matte-free technology with simultaneous modification of the matte line for processing converter matte; the development of a jarosite technology of iron deposition from a nickel solution, which decreased the irreversible losses of nonferrous and precious metals with a waste iron cake as much as possible (the losses of nickel and cobalt were decreased by 11 times; those of copper, by 23 times; platinum, by 16%; palladium, by 10%; rhodium, by 9%; gold, by 12%); and the building and introduction of carbonate processing, which allowed the production of nickel cathodes to be increased. As a result of the measures taken to redistribute raw materials, the mattes of slag-cleaning furnaces, which contained 35–40% Fe, were moved to KGMK. This integration solution led to a significant synergy effect in Nornickel. One of the key factors of the economic efficiency of the matte-free technology was a decrease in the specific consumption of the main reagents (oxygen, air, sulfuric acid) and the energy resources used for the manufacture of nickel products. As a result, the transaction costs were decreased by ~3.5 mln dollars per year. © 2019, Pleiades Publishing, Ltd

Pecularities of training of qualified specialists in condition of establishment of ural engineering school

В статье рассматриваются вопросы подготовки кадров для наукоемких отраслей промышленности, в частности металлургии. Обозначена специфика начального, среднего и высшего профессионального образования. Авторами представлен алгоритм создания и апробации учебно-методических материалов, используемых для подготовки специалистов со средним профессиональным образованием, готовых по окончанию колледжа работать в компаниях со сложным наукоемким оборудованием.Personnel training for knowledge-intensive industries, in particular metallurgy, is analyzed in the article. The article includes general characteristics of the personnel training with primary, secondary and higher professional education. The authors show the algorithm of creation and testing of educational-methodological documentation for training of specialists with secondary professional education and training procedure of specialists who are ready to work for companies with complex manufacturing equipment immediately after graduating from college

Pressure leaching of the Ural enrichment plants concentrates

An alternative approach to the processing of copper concentrates of the Ural enrichment plants is considered. Experiments were carried out on pressure leaching of the concentrate with the following composition, %: 21.5 Cu, 0.1 Zn, 0.05 Pb, 0.04 Ni, 26.59 S, 24.52 Fe, 16.28 SiO2. Two variants of the process directing are considered - high-temperature and low-temperature autoclave oxidative leaching, for which optimal process parameters are proposed: t = 190–210 °C, PO2 = 0.4–0.6 MPa, СН2SO4 = 0–15 g/L and t = 105–108 °C, PO2 = 1.3–1.5 MPa, CH2SO4 = 75–90 g/L, respectively. The chemical composition of leach products is given and ways of their further processing are suggested.В работе рассмотрен альтернативный подход к переработке медных концентратов Уральских горно-обогатительных фабрик. Проведены эксперименты по автоклавному выщелачиванию концентрата следующего состава, %: 21,5 Cu, 0,1 Zn, 0,05 Pb, 0,04 Ni, 26,59 S, 24,52 Fe, 16,28 SiO2. Рассмотрены два варианта ведения процесса - высокотемпературное и низкотемпературное автоклавное окислительное выщелачивание, для которых предложены оптимальные параметры ведения процесса: t = 190–210 °C, PO2 = 0,4–0,6 МПа, СH2SO4= 0–15 г/дм3 и t = 105–108 °C, PO2 = 1,3–1,5 МПа, СH2SO4= 75–90 г/дм3 соответственно. Приведен химический состав продуктов выщелачивания и предложены пути их дальнейшей переработки

Кондиционирование кеков окислительного автоклавного выщелачивания халькопиритного концентрата

The existing technologies for copper-porphyry ores enrichment, located in deposits in the Urals of Russia, allow the production of chalcopyrite concentrates of the following composition, %: 21.5 Cu, 24.5 Fe, 26.5 S, 0.4 Pb, 17.6 SiO2, 1.8 CaO, 2–6 Au (ppm), 20– 40 Ag (ppm). A conventional technology for processing such concentrates includes autogenous smelting, matte desulfurization and blister copper refining. Pressure oxidation leaching (POX) is considered the most promising alternative technology for chalcopyrite concentrate processing. The POX of concentrates originated from Mikheevskii GOK allow the production a cake of the following chemical composition, %: 56–65 Fe2O3, 25–30 SiO2, 2.7 Ca, 0.3–1.0 Cu, 2–7 S, 0.6–0.8 Pb, 4–12 Au (ppm), 40–80 Ag (ppm); mass loss was 37–45 %. A standard method of cake cyaniding provides satisfactory indicators of precious metal extraction, but it requires a cumbersome area to be arranged for their processing and offers no solution for residue disposal. In this regard, this paper investigates the method of subsequent cake processing using autoclave treatment (AT) for iron removal. The study shows how the following parameters affect the results of this process: t = 110÷210 °C, H2SO4 = 15÷60 g/dm3, τ = 45÷ ÷120 min. A statistic description of the AT operation is developed. Recommended AT conditions (t = 110 °C, H2SO4 = 60 g/dm3, τ = 60÷100 min) allow to obtain the POX cake yield reduced to 30–35 % of the source material with the following composition, %: 28–33 Fe2O3, 47–53 SiO2, 2–5 Ca, 0.6–2.0 Cu, 0.8–1.5 Pb, 2–8 S. At the same time, the content of precious metals in the cake reaches 12–16 Au (ppm) and 80–120 Ag (ppm). Options for using AT products are proposed.При флотационном обогащении медно-порфировых руд месторождений Челябинской области (Южный Урал) получают халькопиритные концентраты состава, мас.%: 21,5 Cu, 24,5 Fe, 26,5 S, 0,4 Pb, 17,6 SiO2, 1,8 CaO, 2–6 Au (ppm), 20– 40 Ag (ppm). Классическая пирометаллургическая технология переработки такого сырья включает автогенную плавку, конвертирование штейна и рафинирование черновой меди. Наиболее перспективной альтернативной технологией переработки халькопиритных концентратов считается автоклавное окислительное выщелачивание (АОВ), в результате которого образуется кек следующего состава, мас.%: 56–65 Fe2O3, 25–30 SiO2, 2,7 Ca, 0,3–1,0 Cu, 2–7 S, 0,6–0,8 Pb, 4–12 Au (ppm), 40–80 Ag (ppm), – выход которого составляет 55–63 %. Стандартный метод цианирования кеков позволяет достичь удовлетворительных показателей извлечения благородных металлов, однако требует организации громоздкого участка их переработки и не решает проблему утилизации остатка, в связи с чем в настоящей работе исследован способ доработки кеков с применением автоклавного кондиционирования (АК) для удаления железа. Показано влияние на результаты этого процесса следующих параметров АК: t = 110÷210 °C, исх. H2SO4= 15÷60 г/дм3, τ = 45÷120 мин. Построено статистическое описание операции АК. Предложены условия AК (t = 110 °C, исх. H2SO4 = 60 г/дм3, τ = 60÷100 мин), при которых выход кека операции АОВ снижается до 30–35 % от массы исходного материала и имеет следующий состав, %: 28–33 Fe2O3, 47–53 SiO2, 2–5 Ca, 0,6–2,0 Cu, 0,8–1,5 Pb, 2–8 S; в то же время содержание благородных металлов в кеке достигает 12–16 Au (ppm) и 80–120 Ag (ppm). Предложены варианты использования продуктов АК

АВТОКЛАВНОЕ ВЫЩЕЛАЧИВАНИЕ МЕДНЫХ МЫШЬЯКСОДЕРЖАЩИХ ШТЕЙНОВ РАСТВОРАМИ СУЛЬФАТА МЕДИ

The topicality is shown to improve the processing technology of complex polymetallic raw material containing a considerable amount of toxic impurities of arsenic and lead. Results on pressure leaching the mattes acquired after reduction smelting the dusts of OAO Sredneural’skii Copper Smeltery (SUMZ) by solutions of copper sulfate are discussed. These mattes contain a considerable amount of lead and arsenic. According to the data of X-ray phase analysis of matte samples, phases of sulfides (PbS, PbS·As2S3, Cu2S, FeS, and (Zn,Fe)S) and arsenides (FeAs2, Cu3As, FeAs, and Cu0,85As0,15), as well as inclusions of metallic copper, are revealed in them. Optimal parameters of matte leaching by copper sulfate solutions are the temperature of 150–180 °C, acidity from 5 to 30 g/dm3, and copper concentration of 14–32 g/dm3. This process made it possible to extract 85 % As into the solution, while copper and lead remained in the cake in this case.Показана актуальность совершенствования технологии переработки сложного полиметаллического сырья, содержащего значительные количества токсичных примесей – мышьяка и свинца. Обсуждаются результаты по автоклавному выщелачиванию растворами сульфата меди штейнов, полученных после восстановительной плавки пылей ОАО «Среднеуральский медеплавильный завод» (СУМЗ), содержащих наряду с медью значительное количество свинца и мышьяка. По данным рентгенофазового анализа образцов штейнов в них выявлены фазы сульфидов (PbS, PbS·As2S3, Cu2S, FeS, (Zn,Fe)S) и арсенидов (FeAs2, Cu3As, FeAs, Cu0.85As0.15), а также включения металлической меди. Установлены оптимальные параметры выщелачивания штейнов растворами сульфата меди: температура 150–180 °C, кислотность от 5 до 30 г/дм3, концентрация меди 14–32 г/дм3, что позволило извлечь в раствор 85 % As, а медь и свинец при этом оставались в кеке