The development of copper smelting technology has experienced a long process,but now it’s still mainly use pyrometallurgy,its copper production accounts is about 85% of the world’s total copper.Henan Longjiang metallurgical chemical equipment Co.Ltd.(the following abbreviation Longjiang) reverberatory furnace and blast furnace are also dominated by pyrometallurgy. 　　　

    Pyrometallurgy   Generally,first increase the ore containing copper a few percent or parts per thousand to 20~30% by dressing,as copper concentrate,is matte smelted in ISF(imperial smelting furnace),reverberatory furnace,electric furnace or flash furnace,molten sulfur(matte) output is blown into the converter to make crude copper,then in another reverberatory furnace,after oxidation,refining,impurities cast or cast anode electrolysis,get electrolytic copper of up to 99.9% grade.This process is brief,adaptability is strong,the recovery rate of copper can up to 95%,but because that the sulfur in ore will become sulfur dioxide in the process of matte smelting and converting,which is not easy to recycle and easy to cause pollution.Recently it appears bath smelting such as Baiyin bath smelting,Noranda Process,and Mitsubishi Process of Japan,pyrometallurgy is gradually developing along the line of serialization and automation. 　　　　　　

    Fire-refining of crude copper: 　　　　　　

    Fire-refining principle: Most of the impurities in the crude copper are more approachable than Cu for O,moreover,the solubility of the impurities oxide in Cu is very small,therefore,the impurities get out as oxide slag.Oxidation process produces excess copper oxide in copper,eventually we need to restore to get crude copper.The crude refining process can be divided into oxidation and reduction process. 　　　　　　

    1.oxidation process(oxide slag removal stage) 　　　Air enters into copper melt,first react with copper and generate Cu₂O,then react with other metal impurities to oxygenize impurities,the chemical reaction is as follows:4Cu+O₂→2Cu₂O Cu₂O+Me→MeO+Cu ,Me stands for metal impurities. 　　　 

    2.reduction process(reduction to get anode copper) After oxide slag removal,there is Cu₂O in copper liquid,we use reductant for reduction: Cu₂O+H₂→2Cu+H₂O Cu₂O+CO→2Cu+CO₂ Cu₂O+C→2Cu+CO Reductants are:heavy oil,natural gas,liquefied petroleum gas,charcoal etc..The anode copper is sent to electrolysis workshop for electrolytic refining. 

    Electrolytic refining of copper:the electrolytic refining of copper is casting the copper fire-refined into anode plates,with copper slice as anode piece,alternately into the electrolytic cell,then use aqueous solution of cupric sulfate and sulfuric acid as electrolyte,under the effect of direct current(DC),copper and metal of negative potential on the anode dissolve in solution,while the precious metals and some metals(Se,Te) insoluble,as the anode mud deposited on the bottom of the cell,the copper in the solution will be separated out firstly on the anode. 　　　 　　　

    Longjiang can provide all equipment from concentrate to crude copper process,namely blast furnace,reverberatory furnace,rotary kiln,converting furnace,dore furnace,continuous converting furnace and other complete sets of equipment and accessories. 　　　

    Modern Hydrometallurgy    It contains sulfating roasting-leaching-electrodeposition,leaching-extraction-electrodeposition,bacterial leaching etc.,it is suitable for the heaping leaching,tank leaching choice,underground leaching of low grade complex ore,oxidized copper ore,scrap ore containing copper.Hydrometallurgical technology is gradually applied,predicted can up to 20% of total production till the end of this century.The recommend of hydrometallurgy will reduce the cost of copper smelting greatly.