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In this work, we analyse and structure the information on the distribution of noble metals during pyrometallurgical processing of copper-sulphide and copper-nickel concentrates, available in domestic and foreign scientific sources. The data on the influence of oxygen partial pressure in the system and, consequently, the matte composition, process temperature, and the phase composition of slag on the distribution of platinum group metals, gold, and silver between the smelting products were analysed. Broad-ranging information on the distribution of the examined metals between matte and slag in the processing of copper-sulphide and copper-nickel concentrates was studied. It was established that the distribution of noble metals between the products of smelting using modern analytical methods is still in its early stages. Contradictory information on the behaviour of gold, silver, and platinum group metals during the pyrometallurgical processing of copper-sulphide and copper-nickel concentrates is presented in literature due to the variations in the experimental procedures, preparation, and analysis of test samples, and, as a result, further interpretation of the obtained results. Furthermore, no data on the influence of such technological parameters as magnetite content in the slag phase, the relationship between copper and nickel in the initial furnace charge and obtained mattes on the distribution of gold, silver, and platinum group metals between the products of smelting are available. In addition, no information on the distribution of noble metals during the pyrometallurgical slags depletion obtained in oxidative smelting of copper-nickel production has been published. Thus, it was decided to perform further research on establishing optimal technological conditions for oxidising smelting of copper-sulphide and copper-nickel concentrates, as well as pyrometallurgical depletion of slags, allowing for the highest extraction rates of noble metals into the target product.

Conventional converting of nickel-bearing copper mattes in horizontal Peirce – Smith converters does not conform with the current environmental regulations. A general global trend includes a transition from conventional batch converting to a continuous converting process producing running slags. The main purpose of the continuous matte converting process is to obtain commercial blister copper that would not require oxidation during further anode refining. To achieve this, rational process parameters should be strictly maintained. The existing method of monitoring the Vanyukov furnace process that is based on the product analysis is a prerequisite but cannot ensure real-time process control. The blister copper obtained through continuous converting differs from the one obtained through the conventional technology in terms of oxygen and nickel concentrations. That’s why its composition should be constantly monitored. The authors looked at how the composition of blister copper obtained through continuous converting of matte tends to change. Samples of blister copper of different compositions were synthesized that are typical of the start-up mode. When the process temperature rises, the required product characteristics can only be obtained if the oxidation potential is higher. This results in a higher concentration of oxygen in blister copper. Mathematical dependencies were derived between the concentrations of nickel and sulphur in the product at various temperatures and the concentration of oxygen. A technique is proposed that enables a real-time monitoring of impurities in blister copper.

This paper looks at substantiating the choice of a pyrometallurgical technique for processing of copper-nickel sulphide concentrates with a high concentration of platinum group metals. For this, it is proposed to use a modified SWOT analysis, which was also tested. The paper considers a classical SWOT analysis and its stages and gives examples of its application in different industries. Constraints have been identified for the pyrometallurgical processes recommended for analysis. Internal and external factors have been defined for the recommended pyrometallurgical processes. Each of the factors has been assigned relevance and impact coefficients with regard to an appropriate process. The obtained results have been included in an integrated estimator matrix. The obtained results have been evaluated on the basis of such indicators as overall, internal and external SWOT coefficients expressed as figures. The resultant data served as the basis for recommending the relatively most effective processes that would enable to achieve the project goals. This study can be used to issue recommendations on choosing the most advanced pyrometallurgical techniques for copper-nickel sulphide concentrates that will help reduce the number of processes involved and conduct a further detailed feasibility study. The given indicators may change considerably depending on the factor linked to the production hazards. That’s why a stability calculation was performed additionally for the overall SWOT estimates in relation to this criterion. The change dynamics of the overall coefficients is reflected in the graphs. Depending on the selected level of production hazards some processes may swap on the efficiency scale. The authors offer their recommendations on optimum processes that will enable to achieve the project goals considering the above mentioned factor.

The world’s nickel producers rely on the use of sulphide and oxidized nickel ores, which can vary greatly in terms of their characteristics and cost effectiveness. The Russian Federation is the world’s leading nickel producer, and it is currently exploiting copper and nickel sulphide ore deposits. At the same time, the country houses a considerable amount of oxidized nickel ores (ONOs), which are almost out of industrial use at the moment. At the same time, such ores serve as the main source of nickel abroad, and foreign countries have a vast experience of developing such deposits, and research is ongoing on the subject. One of the major issues related to the poor effectiveness of known techniques for processing ONOs found in Russia is a low concentration of nickel in such ores. This limits the applicability of certain solutions. It would be interesting to compare different ONO processing techniques and analyse their applicability to the deposits found in the Urals. The paper points out that, regardless of numerous pyrometallurgical and hydrometallurgical processes applicable to ONOs, developing new processes remains an important task, especially in application to the ONOs found in the Urals. Such new process should be able to yield high-grade nickel and cobalt products, make use of high-iron and high-magnesium ores, and ensure maximum recovery of commercial nickel and cobalt. The most promising process applicable to the ONOs found in the Urals includes either nitric acid leaching with further processing of leaching solutions or the use of combination processing schemes. © 2019, "Ore and Metals" Publishing house. All rights reserved.

The viscosities of the slags that form during the continuous converting of copper mattes and concentrates into blister copper are determined. The compositions of SiO2-CaO-Al2O3-FeOx-Cu2O-NiO slag melts are varied over a wide range of (Fe + Ni) concentrations (25.5–40.2 wt %) and ratios SiO2/CaO (0.25–3.9) and (Fe)/(Cu + Ni) (0.4–1.6). The slag viscosity is measured by a vibrational method in the temperature range 1050–1450°C. The viscosity of a homogeneous melt is shown to be 0.5–2.0 P, and it increases sharply below the primary solidification temperature.

The surface tension and density of the slags that form during the continuous converting of copper mattes and concentrates into blister copper are determined. The slag melt compositions are varied over a wide range of (Fe + Ni) concentrations and SiO2/CaO and (Fe)/(Cu + Ni) ratios. The surface tension and density are measured by the bubble pressure technique. The concentration of iron and nickel in a slag and the (Fe)/(Cu + Ni) and SiO2/CaO ratios affect the density and surface tension.

The structure and liquidus temperature of the SiO2-CaO-Al2O3-FeOx-Cu2O-NiO slags that form during continuous converting of copper mattes and concentrates into blister copper are analyzed. The slag melt compositions are varied over a wide SiO2/CaO range. The slags are studied by X-ray diffraction, scanning electron microscopy, and electron-probe microanalysis. The liquidus temperature of the slags is determined by differential thermal analysis. It is found that, depending on the SiO2/CaO ratio, the structure and liquidus temperature of the slags change and the forms of copper in a slag also change. The SiO2/CaO range in a slag is recommended for the process of continuous converting of a copper nickel-containing sulfide raw materials.

The structure and liquidus temperature of the SiO2-CaO-Al2O3-FeOx-Cu2O-NiO slags that form during continuous converting of copper mattes and concentrates into blister copper in a Vanyukov furnace used as a melting unit are studied. The slag melt compositions are varied over wide limits of the total (Fe + Ni) and (SiO2 + CaO) concentrations by changing the consumption of fluxing components. The slags are investigated by X-ray diffraction, scanning electron microscopy, and electron-probe microanalysis. The liquidus temperatures of the slags are determined by differential thermal analysis. It is found that, as the consumption of fluxing components changes, the concentration of iron-nickel spinels based on trevorite NiFe2O4 changes substantially and the forms of copper change in the slags. The results obtained are used to recommend the optimum consumption of fluxing components for the process of continuous converting.

A brand new process of blister copper production from copper matte and concentrates in the two-zone Vaniukov converter has been developed at the Gipronickel Institute facility. Thermodynamic analysis of exchange interaction has been performed for the ‘slag melt-metal phase formed in the over-the-lance area of the Vaniukov converter reduction zone’ system and for ‘slag melt-bottom phase of blister copper located in the bottom (under-the-lance) area of the Vaniukov converter’ system. Based on the thermodynamic analysis data, the original design of the two-zone Vaniukov converter has been proven to be able to create conditions ensuring production of blister copper of higher quality, as compared to the one-zone Vaniukov converter process, copper concentration in slag being substantially lower.

Gipronickel Institute is developing a brand new process of Kempirsay Deposit’ nickel oxide ore treatment to ferronickel based on Vaniukov Furnace smelting technology. Results of the extended laboratory scale tests using the pilot Vaniukov two-zone Furnace are presented. It is demonstrated that treatment of relatively poor nickel oxide ore (Ni, 1·05 mass-%) according to the abovementioned technology can result in production of high grade ferronickel (Ni⩾20%) at high nickel recovery (>90%). Technological peculiarities of the processes taking place in the furnace’ smelting and reduction areas are considered. L’Institut Gipronickel est en train de developper un procede entierement nouveau pour le traitement du minerai d’oxyde de nickel en ferronickel du depot de Kempirsay, base sur la technologie de fonte du four Vaniukov. On presente les resultats des essais approfondis a l’echelle du laboratoire utilisant le four pilote Vaniukov a deux zones. On demontre que le traitement de minerai d’oxyde de nickel a tene...

The possibility of applying Wilson’s polynomial to the description of concentration dependences of thermodynamic functions in binary liquid metallic systems and to the calculation of thermodynamic properties of ternary systems from the data on boundary binary systems was considered.

Data on boundary binary systems in conjunction with geometric models and the Redlich-Kister method were used to calculate the integral thermodynamic characteristics and the activities of the components for liquid Cu-Ni-Co-Fe alloys at 1600°C.

Data on the thermodynamic properties of boundary binary systems were used to calculate the activities of components in liquid alloys of the iron-cobalt-nickel ternary system at a temperature of 1600°C.

A mechanism of corrosive interaction between periclase-chromite, periclase, and chromite refractories and molten copper (I) oxide and slag melts containing copper oxide and nickel oxide has been studied. The refractories in question are shown to be insufficiently resistant to slag attack typical of smelting technologies for converting nickel-containing copper sulfide mattes into blister copper.

The integral thermodynamic characteristics and copper activity in liquid alloys of the system nickel-copper-cobalt at 1600°C were calculated by various methods from data on boundary binary systems.

The activities of copper in liquid nickel-copper-iron alloys at 1600°C were calculated along sections with constant xNi : xFe ratios of 3 : 1, 1 : 1, and 1 : 3 (xi is the mole fraction of a component in an alloy).

The equilibrium between a copper-nickel alloy and an oxide melt in the Cu2O-NiO-SiO2 system was studied experimentally. The distribution coefficients of nickel were determined as a function of the content of silicon dioxide, and the ratio of activity coefficients of nickel and copper oxides at 1300°C was found.

An experimental study of the equilibrium between the bottom phase (sulfide melt or copper) and slag in neutral and oxidizing atmospheres yielded dependences of the content of dissolved copper, nickel, and cobalt in the slag on that of sulfur in the sulfide melt and also the dependence of the content of dissolved copper and nickel on that of nickel in the metallic melt. The distribution coefficients of the metals between copper and slag were determined and compared with the results of other investigations.

Published data on phase transformations of iron, nickel and cobalt arsenides and sulfoarsenides under thermal treatment are reviewed.

Equilibria between a copper-nickel alloy and oxide melt of the binary system Cu2O-NiO were studied and the activity coefficients of copper and nickel oxides at 1573 K in the homogeneity region of the oxide melt (up to 11.6 mol % NiO) were determined. Similar values were also found by calculation from the phase diagram of Cu2O-NiO.

The fractionation of sulfur isotopes, namely, enrichment of the cinder with the heavy isotope 34S in the course of roasting of various sulfide ores and concentrates in neutral and oxidative atmospheres at 773-973 K was studied.

The solubility of carbon in iron-nickel sulfide melts at 1673 K was studied in the entire range of compositions of the Fe-FeS-Ni3S2-Ni tetragon. The boundaries of the stratification area were determined in this system upon its being saturated with carbon. Lines of carbon isosolubility are plotted in the tetragon field outside the stratification area.

Applicability of the Zdanovskii rule to melts of the systems Fe-Ni-S and Cu-Ni-S was studied.

The simplest polynomial expressions were applied to the description of the concentration dependences of integral molar excess Gibbs energy and enthalpy of mixing of the Fe-Ni, Co-Fe, and Co-Ni liquid alloys.

Activities of iron and nickel in the copper-rich part of the Cu-Fe-Ni system in the liquid state at 1350°C were calculated using model concepts from data on the boundary binary systems.

Published data on thermodynamic properties of the Ni3S2 compound in the liquid and solid states are compared and discussed.