Recycled copper treatment process depends on the raw material, about 2/3 of the high-grade copper waste does not need smelting treatment and directly used in the production of copper products, 1/3 of the copper scrap needs smelting treatment. At present, there are many methods for recycling copper scrap at home and abroad, which can be divided into two main categories: the first one is to smelt high-quality copper scrap directly into purple refined copper or copper alloy for users to use, which is called direct utilization; the second one is to smelt copper scrap into anode plate and then electrolytically refine it into electrolytic copper for users to use, which is called indirect utilization. Among them, the second type of method is categorized into high-grade and low-grade according to the raw materials, and the smelting process is categorized into one-stage, two-stage and three-stage smelting.
One-stage method: copper grade > 98% of the purple copper, copper, copper, electrolytic residual electrode, etc. directly into the refining furnace refining into anode, and then electrolysis production of copper cathode.
Two-stage method: waste copper is melted in the smelting furnace, blown into crude copper, and then refined in the refining furnace - electrolytic refining to produce copper cathode.
Three-stage method: miscellaneous copper scrap and copper-containing wastes are melted in blast furnace (or ISA furnace, TBRC furnace, Kaldor furnace, etc.) - converter blowing - anode refining - electrolytic refining, producing copper cathode. The raw material grade can be as low as 1% copper.
Three-stage method of high utilization of raw materials, the output of the soot composition is simple, easy to deal with, the crude copper grade is higher, the refining furnace operation is easier, the equipment productivity is also relatively high, but there are process complexity, equipment, investment and fuel consumption and other shortcomings. Therefore, the smelting of regenerated copper generally use two-stage method and three-stage method combined with the process, this method is conducive to reducing energy consumption and improve the comprehensive recycling of valuable metals.
