STUDYING THE THERMOCHEMICAL CHARACTERISTICS OF SINTERING WITH ALKALI CONCENTRATE FROM WASTE COPPER TAILINGS

Abstract

A long period of deposit development leads to a reduction in the volume of balance reserves of ores, while the volume of accumulation of waste (tailings) from mining and processing production increases. In connection with this, an urgent problem is the processing of waste tailings, which can serve as an additional source of commercial products of non-ferrous metals. The set objectives can be achieved by implementing comprehensive extraction of valuable components, reducing fuel, and energy costs at the stage of low-temperature sintering to produce white soot (grade BS-100). In order to determine the amount of heat of chemical reactions during sintering of rough copper concentrate with sodium hydroxide, thermochemical calculations were carried out. For the research, we used rough copper concentrate with a copper content of 4.40% and silver of 77.03 g/t. An equation has been obtained for calculating the heat of chemical reactions of rough concentrate sintering. According to this equation, the greatest contribution to the heat release is provided by the iron content (60%), three times less and equally (19%) - copper and silicon and about 0.2% is absorbed by aluminum. The thermal effect of sintering will be -920.45 kW·h/t of concentrate. From the heat balance of sintering it follows that with an alkali consumption of up to 200% of the mass of the concentrate. The heat of chemical reactions will be sufficient for the autogeneity of the process. Research has been carried out on sintering the concentrate with alkali in the temperature range of 250-500 °C and obtaining white soot from a productive leaching solution with the extraction of 60% silicon. White soot (mSiO2·nH2O) was isolated by two-stage carbonization of a silicate solution with carbon dioxide in a recirculation system with further washing of the precipitate with a solution of sulfuric acid. For citation: Karimova L.M., Kairalapov Ye.T., Makascheva G.K., Kharchenko Ye.M. Studying the thermochemical characteristics of sintering with alkali concentrate from waste copper tailings. ChemChemTech [Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol.]. 2024. V. 67. N 7. P. 72-79. DOI: 10.6060/ivkkt.20246707.7004.