PROSPECTS FOR THE EXTRACTION OF CHROMIUM FROM SLAG FERROCHROME PRODUCTION BY ACID METHOD
Keywords:ferrochrome production, chromium-containing slags, leaching, sulphuric acid, hexavalent chromium, trivalent chromium
Introduction. In the Republic of Kazakhstan, there is a noticeable upward trend in the volume of industrial waste, including from the production of ferrochrome. The problems of man-made pollution of the natural environment are becoming more acute every year, and are beginning to take on a global dimension. Technogenic ferrochrome production waste contains chromium, which is highly toxic and carcinogenic, which poisons water, soil, negatively affects the activity of all living organisms. Slags contain a significant number of valuable components used in various industries, and above all, chromium, which is irrevocably lost during storage. The main task still remains the development of industrial waste disposal processes that reduce the anthropogenic load on the biosphere and ensure the rational use of natural resources. The purpose of the work is to justify the choice of the method of processing the slags of the ferrochrome production. Conclusions: The analysis of the modern scientific and patent literature on acid processing and utilization of chromium-containing slags from the production of refined and high-carbon ferrochrome has been conducted. It should be noted that the described methods of various methods of processing ferrochrome production slags, despite their availability, are characterized by a multi-stage nature and do not allow complete processing of ferrochrome production slags in Kazakhstan. Currently, there is an excess of sulfuric acid production in Kazakhstan, so it becomes advisable to use sulfuric acid as a reagent for leaching chromium from slag from the production of ferrochromium. It can be expected that in sulfuric acid under certain conditions, such as heating, a sufficiently high degree of extraction of chromium (III) will be achieved in slags from the production of high-carbon chromium and in refined ferrochem slags.