Increasing the level of safety and occupational hygiene during the ecologically oriented processing of leather industry waste and the peculiarities of their microstructure

Abstract

The article is devoted to the study of the peculiarities of the microstructure of cinders from leather industry waste. This is necessary for the use of the obtained material as a chromium-containing raw material for the production of alloying additives by aluminothermic melting. To achieve this goal, a complex of the latest research methods was applied using raster electron microscopy together with X-ray microanalysis to determine the chemical composition of the target areas of the surface of the samples. Thanks to the successfully conducted stages of research, significant results were obtained with the determination that the cinder microstructure was disordered, porous and consisted of separated particles of different shapes and sizes. The oxide nature of the majority of the components is due to the detection of oxygen in the analysis areas in the range of 14.04-25.12 %wt. In the studied areas, the chromium content was at a relatively high level — from 59.49 %wt. up to 74.64 %wt. Of the refractory elements, vanadium was also present in the amount of 0.18-0.29 %wt. The iron content ranged from 0.41 to 0.62 %wt. At the same time, some content of accompanying impurities Ca, Mg, Al, Na, Si, Cl, Mn, K, as well as S and P was found in the cinder — in the amount of 0.55-1.52 %wt. and 0.12-0.21 %wt. in accordance. This made it possible to draw a number of important practical conclusions that the obtained product requires the use of aluminothermic refining smelting for further effective use as an alloying chromium-containing additive. At the same time, cinders from leather production waste can be added instead of part of the chromium-containing ore concentrate when smelting ferrochrome. At the same time, the processing and return to production of technogenic waste from leather production ensures an increase in the level of safety and occupational hygiene, a reduction in environmental stress in industrialized areas, a reduction in environmental pollution and an increase in the safety of life.