Selection of sorption materials for the extraction of nickel and cobalt from the ore of the Gornostaevskoye deposit

Oxidized nickel ores account for the majority of industrial ores suitable for nickel production. The processing of such ores using traditional pyrometallurgical technology is not economically viable due to the low nickel content. One of the most cost-effective methods of processing oxidized nickel ores is sulfuric acid leaching technology followed by sorption extraction. The aim of this work is to establish the kinetic and thermodynamic parameters of the sorption extraction of nickel and cobalt using iminodiacetate chelating ion-exchange sorbents from various manufacturers, to select a desorbing solution and to determine the degree of desorption. The sorption of nickel and cobalt was carried out in a weakly acidic medium from a model solution containing impurities of other metals in static and dynamic modes. The limiting sorption capacity for the studied sorbents is 18-26 mg/g for nickel and 1-2 mg/g for cobalt in the static mode. The sorption capacity in the dynamic mode for nickel is equal to 25.5 g/L for Purolite S 930, 29.2 g/L for Lewatit TP 207, 1.4 g/L, and 1.8 g/L for cobalt, respectively. The best desorption parameters are achieved when using a 2 M sulfuric acid solution. The degree of desorption for sorbents Purolite S 930 and Lewatit TP 207 exceeds 90%. The use of the Lewatit TP 207 sorbent for the extraction of nickel from the leaching solution of nickel ore of the Gornostaevskoye deposit in 5 cycles made it possible to obtain a commercial desorbate with a nickel content of 18 g/L. The use of a part of the commercial desorbate obtained in the previous cycle, further strengthened to the initial concentration of sulfuric acid, for re-extracting nickel from the saturated sorbent during a cyclic process leads to a deterioration in desorption characteristics. It is recommended to remove the commercial desorbate from the process after several cycles of desorption and supply new solution of sulfuric acid for desorption to restore the sorption parameters.

Nickel Sorption from Sulphate Solutions of Oxidized Nickel Ores Leaching

The possibility of sorption extraction of nickel from leaching solutions of oxidized nickel ores of the Buruktal deposit is considered. Ionite Lewatit TP220 with bis-picolylamine functional groups is effective for nickel recovery against the background of high iron contents. Lewatit TP220 is mechanically strong enough for use in the resin-in-pulp process. Nickel sorption with satisfactory performance occurs both in the variant of sorption leaching and extraction from clarified solutions. At sorption from the pulp, the capacity for nickel was 5.44 mg/g, for iron, 25.17 mg/g. The use of 20% sulfuric acid provides quantitative nickel desorption. To obtain a higher quality nickel-containing product, it is recommended to additionally purify the resulting eluates from iron.

The Study of Physicochemical Features of Laterite Ores of the Buruktalsky Deposit

Currently, there are practiced various pyrometallurgical, hydrometallurgical, and com-bined pyro and hydrometallurgical methods for processing of oxidized nickel ores to produce metal-lic nickel, cobalt, and their compounds in non-ferrous metallurgy. The problem is the difficult ore concentration, and consequently the high consumption of reagents or low extraction of valuable components from it. Ural plants previously implemented the technology of reducing-sulphiding smelting of laterite ore to produce fire nickel and transfer of cobalt to matte. The economic ineffi-ciency of this technology predetermined the search for a new method for processing of significant reserves of oxidized nickel ores in the Ural region.

Technical and Economical Substantiation of the Technology of Joint Pyrometallurgical Processing of Oxidized Nickel Ores and Sulfide Copper Ores

The technological scheme of processing of nickel and copper ores from the Urals deposits is substantiated, including calcination of oxidized nickel ore with limestone, partial oxidative roasting of sulfide copper ore, blending of calcines with coke, and melting of charge to obtain copper-nickel matte. The implementation of the scheme will increase the complexity of possible uses of raw materials and ensure a high environmental protection level. A feasibility study was carried out for the organization of industrial enterprise, which entailed the joint processing of oxidized nickel ores and sulfide copper ores with a capacity of 700,000 tons per year of a mixture of initial ores, including 400,000 tonnes of nickel ore and 300,000 tonnes of copper ore (dry weight). Finished products are: copper-nickel matte, containing not less than, wt.%: 3.3 Cu, 4.7 Ni, 0.6 Co, 1.5 g/t Au, 2.6 g/t Ag; granular slag containing, wt.%: 0.01–0.02 Ni, 0.01–0.02 Cu, 0.01–0.06 Co, 13–16 Fe, 44–50 SiO2, 13–14 MgO, 4–5 Al 2O3, 9–11 CaO; and technical grade sulfuric acid (mass fraction of monohydrate not less than 92.5 %). The planned enterprise is expected to produce the following annual volumes of finished products (not less than): 94,900 tonnes of matte; 512,300 tonnes of granular slag; and 235,500 tonnes of technical grade sulfuric acid. The estimated period of project implementation is 13 years. The total amount of investment costs is 1407 million roubles, current costs for the annual production program are 3820 million roubles. The financial results of the investment project are characterized by the following indicators: net profit is 5,735.5 million roubles, net discounted income is 1546.6 million roubles, the profitability index of discounted investments is 2.1, the internal rate of return is 36.4 %, and the discounted payback period is 5.5 years. The results indicate the viability and economic efficiency of the project. Keywords: ore, processing, sulfides, oxides, copper, nickel, cobalt, smelting, extraction, products, economy, indicators, efficiency

Two-stage hydrochloric leaching of oxidized nickel ore of the Serovsky deposit

Significant reserves of oxidized nickel ores are concentrated in the Ural region, in the deposits of various sizes that are mined by open-pit method. Ore is rather loose, which makes the cost of production relatively low. At the same time, the technologies employed at Ural nickel plants fail to meet the energy conservation requirements, and they are environmentally unfriendly and unprofitable. The paper proposes a two-stage hydrometallurgical technology for processing oxidized nickel ores from the Serovsky deposit. The composition of investigated ore is, wt.%: 1.01 Ni, 0.031 Co, 15.32 Fetotal, 8.51 Al2O3, 21.76 MgO, 43.97 SiO2. The phase composition of the sample was determined by powder diffraction on the XRD-7000 X-ray diffractometer (Shimadzu, Japan). Serpentine Mg6[Ni, Si4O10](OH)8 and nimite (Ni, Mg, Al)6(Si, Al)4О10(OH)8 were identified as the main nickel-containing minerals. Nickel enters the crystal lattice of silicates and replaces magnesium and iron isomorphically, which significantly complicates the disintegration of such minerals by the hydrometallurgical method. The paper provides the results of laboratory studies into atmospheric ore leaching with hydrochloric acid at the first stage and autoclave leaching of the obtained slurry at the second stage depending on temperature, leaching time and acid consumption. The total (in two stages) extraction into the solution was, wt.%: 82 Ni, 73.6 Co, 22 Fe, 22 Mg, 50.4 Al. Hydrochloric acid is almost completely consumed under these conditions with residual acid concentration of about 3 g/dm3. The autoclave slurry has good filterability. Cake composition after autoclave leaching is as follows, wt.%: 0.35 Ni, 0.01 Co, 12 Fetotal, 10.63 Mg, 1.2 Al, 55 SiO2.

The mechanism of thermal decomposition of oxidized nickel ore from the Kulikovskoyе deposit in air

The object of the research is oxidized nickel ores from the Kulikovskoye deposit (Southern Urals) – non-conforming nickel-containing raw materials. The work is devoted to the study of chemical and phase composition to substantiate the choice of the method of processing this material in order to obtain valuable inorganic substances in demand in the chemical and metallurgical industries: oxide and (or) magnesium nitrate, iron and nickel containing concentrates, silicon dioxide. The chemical composition of ore demonstrating the feasibility of developing a technology for its complex processing is presented. X-ray phase analysis showed the presence of silicates of the serpentine group (lizardite-1M and lizardite-1T) and the group of spinelids (magnesioferrite) in the oxidized nickel ores of the Kulikovskoye deposit. A literary analysis suggested the presence of other hydrosilicates (antigorite, chrysotile, nimite, talc, revdinskite, clinochlore, etc.). IR spectroscopic analysis was performed to confirm the phase composition. A thermogravimetric analysis was performed, which makes it possible to determine the conditions for the preliminary preparation of ground raw materials. To determine the mechanism of thermal decomposition of ore in air, intermediate products were obtained at temperatures of 600, 700 and 900 °C. According to X-ray diffraction, IR and Raman spectroscopic analyzes, at 600 °C, the removal of OH groups, water molecules and the destruction of the crystal lattices that make up the mineral ore with the formation of oxides (FeO, SiO2, MgO) begins. At 700 °C, island silicates are formed: forsterite Mg2SiO4, larnite Ca2SiO4. At 900 °C, the interaction between silicates continues with the complication of the composition of functional groups. Based on the described properties of minerals and previous work on the hydrometallurgical technology of processing oxidized nickel ores and metal-containing silicate raw materials in order to obtain inorganic substances, nitric acid is proposed as a leaching agent.

Prospects for the Ferronickel Production Development from the Urals Oxidized Nickel Ores

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