| 摘要 |
The invention is applied in non-ferrous metallurgy. Its application results in achieving high non-ferrous metals recovery from metallurgical semies and secondary raw materials at lower fuel consumption as well as in reducing the dust quantity in the outlet exhaust gases. According to the method, on the grounds of preset process parameters, a charge is made of zinc containing material, the powdered component of the solid fuel and an activator in the ratio of 8-12:2.5-7:0.8-1.5. The charge is mixed and pelletized. The produced pellets, 1-30 mm in diameter, and moisture content of 16-18 % and the rest of the solid fuel, necessary for the process are dosed by a preset program for technological control in the ratio of 3:1 and are fed into the Waelz kiln. Oxygen in the quantity of 3-12 m<3>/t of treated charge is blown in at the discharge end of the kilns. The gases exiting the kilns and containing non-ferrous metals are cooled and pass through a two-stage filtering in a filtering equipment. The dust loading of the exhaust gases after the first stage is up to 350 mg/Nm<3> and after the second stage - below 10 mg/Nm<3>. The metal oxides collected in the filters are pelletized, the pellets sizing 2-6 mm in diameter and the moisture content is 13.6-16 % and after that are sent for thermal treatment in a tube kiln, at the discharge end of which oxygen is blown in the quantity of 5-12 m<3>/t of oxides. The produced roasted metal oxides are further hydrometallurgically processed and the kiln gases are cooled, passed through a filtering equipment and the collected metal oxides are sent for additional cleaning and recovery, where the waste gases contain 4-8 mg/Nm<3> of dust. |
