A concept of micro-mill elaboration and development for low-quality burden and metal-containing wastes recycling

Abstract

The problem of recycling of low-quality burden with increased content of harmful impurities and industrial and domestic metal-containing wastes becomes more and more actual. The solution of it will enable to decrease damage to environment and to obtain useful product out of the secondary raw materials. A concept proposed for creation of micro-metallurgical plants with less comparing with mini-mills, production capacity. The possibility of flexible control of processed liquid and solid burden materials ratio is an important advantage of the micro-mills, taking into account varying prices for raw materials and energy. In the preparation department of the micro-mill it is reasonable to use briquetting by means of two-high presses for pelletizing of fine-fraction materials, used as a part of initial burden. In the melting department depending on the kind of finished product a 130 m3 volume blast furnace or oxygen cupola furnace of 10-15 t/h productivity can operate. For steelmaking a 10-t oxygen converter with rotating housing or small-size EAF can be used. The casting department will provide production of marketable pig iron or steel ingots. It was noted, that in the countries of Europe at steelmaking plants of 50-150 thousand t/year productivity, steel-making facilities are used based on Kal-Do converter principle. A layout of mechanisms of such a converter, perfected by Ukrainian specialists presented. The perfected converter has a modernized drive of the housing rotation mechanism, automatic systems of bath bottom blow-down by an inert gas and gas-dynamic final technological slag cut-off at steel tapping into tapping ladle. New technical solutions, used in the steelmaking aggregate, allow to simplify the operation and maintenance of the housing rotation drive mechanism, as well as to expand the possibilities of technological process flexible control due to provision of rational combinations of the operations and techniques used. Approximate calculations of expenses for production of one ton of product under conditions of industrial metal-containing wastes recycling when using oxygen converter with rotating housing presented.