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 divided into high-grade and low-grade according to the raw materials, and the smelting process is divided 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.
Introduction of main smelting process
1,North German Refining Kaiser Smelter Kaiser Recycling System (KRS)
North Germany Refining Kaiser Smelter is currently the world's largest and most advanced recycled copper refinery. Kaiser smelter with 1 ISA furnace instead of 3 sets of blast furnace and 1 set of PS converter, dealing with copper 1% ~ 80% of the residue and miscellaneous copper; ISA furnace intermittent melting and blowing, copper-containing residue and miscellaneous copper, the first in the ISA furnace for the reduction of melting, the output of black copper and silicate slag, black copper to continue to blowing, the output of 95% of the output of the copper containing copper crude copper.
2,Austria MontanwerkeBrixlegg smelter blast furnace-converter-reflector furnace process
Montanwerke Brixlegg smelter is the only copper smelter in Austria, the raw material is copper scrap, copper content of 15% to 99%. The production process consists of blast furnace, PS converter, fixed anode furnace and electrolysis, which is a typical three-stage method.
The process is characterized by: different grades of residue and purple copper with different processes to produce different products. Residue raw materials containing 15% to 70% of copper advanced blast furnace, coke reduction to produce black copper, and then into the converter to produce crude copper; containing more than 75% of copper black copper and copper alloy directly into the converter to produce more than 96% of copper crude copper into the anode furnace refining; containing copper grade higher miscellaneous copper, crude copper is directly into the anode furnace refining; and copper grade higher bright copper without smelting treatment, directly into the induction furnace The production of copper material is very adaptable to the raw material.
Oxygen Top Blow Rotary Converter (TBRC) Smelting Process in the Metallo-Chimique Smelter, Belgium
The TBRC furnace of the Metallo-Chimique Smelter is highly adaptable to the raw materials, and handles a wide variety of raw materials. The main raw materials are industrial residues containing 25%~30% copper, various copper alloys (brass, bronze, etc.), waste motors, sponge copper, cables, various grades of miscellaneous copper, etc. Especially, it is mainly used to process low-grade industrial residues, copper alloys and difficult-to-treat miscellaneous copper containing copper, lead and tin.
4,Kaldor furnace to deal with low-grade waste copper
Kaldor furnace treatment of low-grade copper scrap is an advanced smelting technology, mainly reflected in the high rate of metal recovery and environmental benefits, etc., can deal with copper-containing 15% -99% of the copper scrap, adaptable, the material does not have to be pre-treated, can be directly into the furnace, you can control the oxidation and reduction of the atmosphere. The treatment of low-grade copper scrap is divided into five steps: charging, melting, slagging, blowing and copper discharge, which are completed in stages in one furnace, and the grade of crude copper can reach 96%. The reaction process usually uses the iron in the copper scrap raw material as the reducing agent and adds quartzite flux. Kaldor furnace treatment of copper scrap process is a foreign two-stage method of copper scrap treatment of an advanced process, the domestic large smelters, such as Jiangxi Copper also introduced the method of copper scrap treatment.
