The sintering process for the preparation of raw materials to be fed to the Imperial Smelting Furnace (I.S.F.) is rather diversified in its characteristics. In comparison to the other preparation process for zinc extraction, i.e., fluidized bed roasting, the sintering process enables the Imperial Smelting Process (I.S.P.) smelter to treat a variety of raw materials.
Process Control of Sintering Plant
Sulfide concentrates, oxide materials and I.S.F. dross are prepared in the proportioning bins (There are ten bins for raw materials.). The raw materials and flux are fed by separate variable speed belt conveyers consisting of computer controlled belt weighers.
Raw materials and crushed return sinter are then mixed and pelletized in mixing and conditioning drums. The moisture content of return sinter is controlled to within 2 – 3 % in the cooling drum as will be explained later. In the mixing drum, the moisture content of the mix is controlled to about 4 – 5 % which is very important for keeping good permeability of the feed mix to the sinter machine.
Feed mix thus uniformed in the preceding process is fed respectively into an ignition and a main layer hopper of the sintering machine by a reversible conveyer. The weight of