The results of experiments on manganese pellets based on beneficiated manganese-containing sludge and the melting of ferromanganese alloy with their use are presented. Via beneficiating manganese-containing sludge (16.32% Mn), a concentrate with a manganese content of 35.2% was obtained. The composition of the charge used to prepare manganese pellets is proposed, and the conditions affecting their strength are determined. It was established that manganese is present in the composition of calcined pellets in the form of jacobsite MnFe₂O₄ and hausmannite Mn₃O₄. The formation of a phase of ferrobustamite (Ca_0.79Fe_0.21)SiO₃, a ferrosilico-calcium binder that helps increase the strength of pellets, was found. Ferromanganese alloy was obtained as a result of the melting of calcined manganese pellets in a high-temperature Tamman-type unit. The Fe-Mn-Si alloy corresponds to the DIN 17 564 as-grade FeMn70Si in terms of manganese (63.76%) and silicon (17.21%) contents. The content of limiting impurity elements—carbon and phosphorus—in ferromanganese alloy is within acceptable limits. The structure of Fe-Mn-Si alloy and slag formed during their smelting process were studied.

The article describes the effect of the fluxing ability (FA) of ores used as a flux on slag formation and copper losses. In Kazakhstan, at the Balkhash copper smelting plant (BCSP), currently used fluxes have a very low SiO₂ content—about 62%—whereas the Al₂O₃ content is 12%. Its fluxing ability (FA) was estimated, and it was shown that currently used silica fluxes have an exceedingly low FA. Only half of the fluxes participate in the slag formation. To obtain slags with a low magnetite concentration, a considerable surplus of flux must be added, which will result in a sharp reduction in its melt temperature, increased slag output, and therefore copper losses. The slag structure was studied by means of scanning electron microscopy and electron probe microanalysis (EPMA). To determine one of the primary causes of flux ores’ low FA, it is necessary to use the microstructural pattern of experimental samples.

Currently, due to the high rate of development of the rare-earth industry, new sources of raw materials are being mastered and new technologies for obtaining rare-earth metals (REM) are being developed. Studies have shown that REM in kaolinite clays of Alexeevskoe deposit in Kazakhstan and Egypt deposits in Sinai Peninsula (K-Watt, K-Tech) and in Aswan region (KB,KPL) are mainly represented by erbium (Er). Production of Er concentrate is considered as a by-product in a comprehensive middlings processing of kaolinite clays to produce alumina and building materials. The possibility of obtaining Er concentrate by sulfuric acid leaching and sorption concentration methods has been determined. Optimal technological conditions of kaolinite clays leaching is the use of 5% solution of H₂SO₄, at temperature 50 °C, duration 60 min and L:S ratio = 5. Under these conditions the separation of REM from the main components Fe₂O₃, Al₂O₃, SiO₂ is achieved. Concentrates were obtained with the content of the sum of REM oxides from 91.3 to 93.4%, in which the relative content of Er was from 64.89 to 90.82%. The results showed that the developed technology can be used for processing of erbium-containing kaolinite clays of various deposits.

Refractory gold ores containing arsenic are difficult to process using conventional beneficiation and cyanide-leaching technologies. They often have a relatively low content of silicon dioxide (no more than 60%) and also contain arsenic. Therefore, they are difficult to use as fluxes in pyrometallurgical production and require separate processing. A technology based on the reduction pyrometallurgical selection process (RPS process) involves direct smelting. The feasibility of direct smelting of highly refractory primary gold ore with the addition of 5–10% sulfide copper concentrates was investigated. Smelting was conducted at temperatures of 1350–1400 °C under a reducing atmosphere. The resulting matte contained up to 100 g/t gold, while the slags produced contained less than 0.1 g/t gold. Gold recovery into the matte exceeded 98%. The gas purification scheme helps to prevent the release of sulfur dioxide and arsenic into the environment. The obtained matte can be processed at copper smelting plants in either solid or liquid form, with copper and noble metals recovered via the standard processing route: converting → fire refining → electrolytic refining → processing of copper electrolytic slimes for noble metal recovery.