COMPREHENSIVE WASTE-FREE PROCESSING TECHNOLOGY OF COPPER SMELTING SLAGS

Abstract

More than 140 million tons of slag have been accumulated in the dumps of copper smelting enterprises of the Russian Federation. Maintaining dumps require significant expenses, which makes it necessary to dispose these production wastes as completely as possible. At the same time, these slags contain valuable elements, in particular, iron, copper, zinc, selenium, arsenic and some others; their extraction can make disposal cost-effective. Among these elements iron has the highest cost, which content is at the level of more than 40%; it is almost at the level of some iron ores used in ferrous metallurgy. However, the use of this iron-containing material in conventional ferrous metallurgy processes is complicated by the high (up to 0.6%) copper content. In addition, the extraction of iron by conventional methods does not solve the problems of disposal of newly formed slag. In this work, the technological methods of processing copper-smelting slags by solid-phase reduction of iron in the Tamman reduction furnace, smelting of reduction products in induction furnaces with the production of metallic iron and propants from the slag residue are proposed and worked out in laboratory conditions. The slags and slurries of the Karabash Copper Smelting Plant, where the main component of is iron, were used as the research material. The properties of cast iron grinding media, as well as ceramic proppants for the use in the oil industry, were investigated. As a result, the influence of elements passing into metal (silicon, carbon, copper and sulfur) on the hardness of grinding balls and the influence of the chemical composition of the slag on the strength of the obtained propants was clarified. A technological scheme of complex slag processing has been developed and a set of serially manufactured equipment has been selected. The economic efficiency of the organization of production is estimated.