MATHEMATICAL MODELLING OF THE TWO-STAGE METHOD FOR SLUDGE AND DUST RECYCLING
Ecological and resource-saving problems determine the relevance of iron-bearing sludge recycling. The main goal of the researches was to estimate prospects for the two-stage combined recycling process for fine-grained zinc-bearing metallurgical wastes. This article provides a survey of main current recycling processes and a suggestion of a new combined two-stage zinc-bearing sludge and dust recycling method. The method’s advantages are proved by the results of laboratory experiments and calculations that were made by means of developed mathematical models. By means of physical modeling we proved the possibility of using solid-phase reduction for zinc-bearing metallurgical wastes recycling. In the experiments we have managed to obtain metallized products with a metallization degree of up to 100 % and a zinc concentrate that may be used as a raw material for non-ferrous metallurgy. By means of mathematical models it was shown that preliminary solid-phase metallization led to a substantial decrease in coal consumption for liquid-phase reduction on the second stage of the combined technology. By using the two-stage technology it is possible to obtain iron with less sulphur and phosphorus content. Besides, it is possible to decrease gas emissions and reduce environmental impacts.