The lead smelting process flow is shown in Figure 2. As can be seen from Figure 2, in the first stage (smelting), lead concentrate, lead residue and lead sulfate residue mixed with silica and limestone are added to the furnace. Fuel coal, lance air, lance oxygen and shielding gas are supplied through the lance. All stages of soot are added during the smelting stage.
Lead metal and residues containing 40wt.% of lead will be produced in this stage. When the metal is removed in stages, the residues will be left for the next stage reaction. When the residual capacity in the furnace reaches the upper limit, the feeding will be suspended. The molten pool will be lowered, initially by adding lead concentrate and lump coal (reduction 1), and then by adding lump coal only (reduction 2). During these two reduction stages, the lead oxide content in the residue was reduced to form lead metal, and the lead content in the residue decreased from 40 wt.% to 5 wt.% after the process.
Osmelt furnace has fast smelting speed, high productivity, low construction investment, low production cost, strong adaptability of raw materials, flexible and convenient matching with existing equipment, easy operation, high degree of automation, wide range of fuel adaptation, and good labor. sanitary condition. However, the life of the furnace is short, and the heat preservation of the spray gun requires diesel or natural gas, which is more expensive.
