JSC “Chelyabinsk Zinc Plant”, Chelyabinsk, Russia:

V. M. Terentev, Leading Engineer-Technologist of Engineering Center
A. A. Kondratyuk, Head of Calcination Shop, e-mail: aak@zinc.ru
E. Yu. Knaub, Senior Foreman of Calcination Shop
V. Yu. Nesmelov, Head of Bureau of Reconstruction and New Equipment of Engineering Center

Provision of stable and regulated process is an urgent task during processing of sulphide zinc concentrates with different chemical and particle size composition in fluid-bed furnaces. This problem is solved by the choice of temperature condition of calcination and calculation of charge composition, as a mixture of various zinc concentrates. The current trend in the change of zinc concentrates’ grainsize composition (average particle size decrease) and increase of their impurities of iron, lead, copper and silica defines the necessity of the studies of the concentrate calcination ability during calcination, which is undesirable for the process in fluid-bed furnace. This article considers the effect of particle size composition on the probability of agglomerative sinter formation during calcination and effect of impurities in the concentrates on the received sinters' strength. The threshold particle size of the concentrates (100 μm) was defined. The value of threshold particle less than 100 μm leads to formation of agglomerative sinter in the process of calcination. Agglomerative sinters with different mechanical strength were obtained during calcination of different concentrates with fixed values of particle size, temperature and time. There was defined the dependence of the sinter strength on iron content in the concentrate (from 20 kPa at 1.43% Fe to 540 kPa at 14.85% Fe). The changes in the process of calculation and charge preparation for calcination in fluidized bed furnaces and furnaces' design were made on the basis of current and previous researches. These changes made possible to prevent adverse effects of the foregoing factors and ensure stable technology management.

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