Research into the solvent extraction of iron(III) from a chloride solution after bauxite HCl leaching by neutral oxygen-containing extractants and their mixtures were studied and the iron(III) extraction degree from chloride solutions using alcohols is presented. The effect of dilution of alcohol with a ketone by an extraction mixture in relation to its effectiveness was investigated. The iron(III) was efficiently extracted by the mixture of 1-octanol and 1-decanol (70%) with 2-undecanone (30%) from hydrochloric bauxite leach liquor at an O:A ratio = 2-4:1 at an iron(III) concentration of 7.4 g/L and 6 M HCl. For the removal of iron-containing organic phase from impurities (Al, Ca, Cr) that are co-extracted with iron(III), we used two step scrubbing at O:A = 5:1 by 7 M HCl as a scrub solution. The iron(III) stripping at the O:A ratio is shown. Using counter-current cascade of extractors, it was possible to obtain an FeCl₃ solution with the iron(III) content of 90.5 g/L and total impurities less than 50 mg/L.

The production of electrolytic nickel includes the stage of leaching of captured firing nickel matte dust. The solutions formed during this process contain considerable amounts of Pb, which is difficult to extraction due to its low concentration upon the high-salt background. The sorption of lead from model solutions with various compositions by synthetic and natural titanosilicate sorbents (synthetic ivanyukite-Na-T (SIV), ivanyukite-Na-T, and AM-4) have been investigated. The maximal sorption capacity of Pb is up to 400 mg/g and was demonstrated by synthetic ivanyukite In solutions with the high content of Cl⁻ (20 g/L), extraction was observed only with a high amount of Na (150 g/L). Molecular mechanisms and kinetics of lead incorporation into ivanyukite were studied by the combination of single-crystal and powder X-ray diffraction, microprobe analysis, and Raman spectroscopy. Incorporation of lead into natural ivanyukite-Na-T with the R3m symmetry by the substitution 2Na⁺ + 2O²⁻ ↔ Pb²⁺ + □ + 2OH⁻ leds to its transformation into the cubic P−43m Pb-exchanged form with the empirical formulae Pb_1.26[Ti₄O_2.52(OH)_1.48(SiO₄)₃]·3.32(H₂O).

This work proposes an environmentally safe and economically feasible method of waste copper-nickel production slag utilization (Kola Mining-Metallurgical Company, Nornickel, Kola Peninsula, Russia). This process involves the decomposition of slag by diluted solutions of sulfuric acid (7–10 wt.% H₂SO₄) with a transfer in a solution of more than 70% silicon, 77% iron and 78% magnesium, and a concentration of non-ferrous metals in the residue (~70%). Copper ions were used in the leaching stage to prevent the release of hydrogen sulfide into the working atmosphere. Dehydration of the solution, followed by washing of water-soluble sulphates from silica, was carried out to separate silica from the leaching solution. The dehydration temperature effect on the silica structural characteristics was determined. The possibility of recovering non-ferrous metals from solutions after silica extraction by precipitation, in the form of copper cementite, and the sum of nickel and cobalt sulfides, was evaluated. Pigment-grade iron dioxide, magnesium sulphate and aluminium hydroxide were obtained by dehydration of the solution after extraction of base metals, calcination and other operations. Sulfuric acid leaching resulted in the disclosure of sulfide grains encapsulated in ferrosilicate, which is a favorable factor for flotation. The depleted residue can be successfully used in the construction industry.

Experiments on extraction of gold(III) from hydrochloric acid solutions with isomeric aliphatic alcohols containing 6–12 carbon atoms showed that secondary alcohols recover AuCl₄₋ from acid solutions with higher distribution ratios than primary alcohols do. The best alcohol that can be recommended for the extraction of gold(III) from 3–6 M HCl solutions, taking into account the solubility and extraction ability of alcohols, is 2-octanol. The possibility of efficient stripping of gold(III) from the 2-octanol phase with ammonia or thiourea solutions was demonstrated.

The article presents studies on the extraction of iron from chloride solutions with aliphatic alcohols, ketones, and their mixtures. Dilution of 1-octanol with an inert aromatic diluent to a concentration of 80 vol.% led to an increase in its extraction capacity, while the extraction capacity of 2-octanone has decreased with dilution. A synergistic effect was found for a 1-octanol/2-octanone mixture, the maximum of extraction was observed at a ketone concentration of 80 vol.%. The effect of a mixture composition and chloride ion concentration on the iron extraction degree was studied. McCabe-Thiele results indicated that at Fe(III) concentration in the aqueous phase 9.32 g∙dm⁻³, it is possible to extract iron(III) quantitatively using a mixture of alcohols C₈+C₁₀ (70 vol.%) and 2-undecanone (30 vol.%) after three extraction stages. Stripping of Fe(III) from the mixture was done with distilled water. After the stripping, the loaded Fe(III) concentration in the organic phase was reduced from 27 g∙dm⁻³ to <0.001 g∙dm⁻³ for 3 stages. The conditions were tested in continuous mode at a cascade of laboratory extractors. During the tests on the cascade, the low solubility of the mixture of ketone with alcohol was established, and the concentrated solution of ferric chloride was obtained.

The possibility of hydrometallurgical processing of converter slag from nickel production aimed at integrated use of mineral raw materials and environmental protection is shown. The scheme of hydrometallurgical processing of slag using hydrochloric acid is proposed. The method involves leaching the slag with hydrochloric acid in the presence of ferric ions. The high values of iron and nonferrous metals extraction into the leaching solution are achieved during hydrochloric acid leaching. Silicon is concentrated in an insoluble residue. Liquid extraction was used to extract iron from hydrochloric acid leaching solutions. Silica-containing residues can be successfully used in the construction industry.