... process, equipment, and technology service of rare value metals such as lead, zinc, copper, gold, silver, bismuth, indium, tellurium etc. ... grade37-55% zinc concentrates and zinc oxide dust.1.4. The raw material source of indium products: indium-rich slag generated in ... the zincsmelting, the reverberatory furnace soot from lead smelting, indium and arsenic dusts from copper smelting.1.5. The raw ...