Modern production methods of nickel mainly are pyrometallurgy and hydrometallurgy.According to the difference of the two major nickel mineral(sulfide ore and oxide ore containing nickel) in the world,smelting process is also different. 　　 

    Sulfur ore containing nickel mainly adopts pyrometallurgy,first roast concentrate,then enter into blast furnace(or reverberatory furnace) for smelting to get copper nickel matte,blow copper nickel matte to get nickel anode,electrolyze nickel anode to get nickel in the end.Oxidized ore is mainly laterite containing nickel,its grade is low,suitable for hydrometallurgy,the main methods are ammoniacal leaching and sulfuric acid method. 　 The pyrometallurgical processing of oxide ore is nickel-iron method,the pyrometallurgical processing of nickel sulfide concentrate as shown as below: 　　　　　　　　　　　　　

    Its main technological characteristics are as follows: 　　　

    Smelting First dry and desulfurize nickel concentrate,then smelt in the blast furnace(reverberatory furnace),its purpose is to make the oxide of copper and nickel turn to sulfide,output low nickel matte(copper nickel matte),while slagging.In the low nickel matte output,the total content of nickel and copper is 8%~25%(generally is 13%~17%),sulfur content is 25%. 

    The converting of low nickel matte The purpose of converting is to remove iron and a portion of sulfur,get high nickel matte(nickel and high-sulfur),not nickel.Converter smelting temperature is higher than 1230℃,due to the low grade of low nickel matte,usually blowing a long time. 　　

    Flotation Fine grind and crush the high nickel matte,separate by flotation and magnetic separation,then get nickel concentrate containing 67%~68% nickel.At the same time,select the copper concentrate and copper-nickel alloy to recovery copper and platinum group metal.Nickel concentrate is smelted by reverberatory furnace to get nickel sulfide,then be sent for electro-refining or be reduced smelting in electric furnace(or reverberatory furnace) to get crude nickel,then electro-refining again. 　　　

     Electro-refining Crude nickel contains copper and diamond,but also contains gold,silver and platinum group metal,should be recovered through electrolytic refining.Unlike copper electrolysis,diaphragm electrolytic cell is used here.With crude nickel as anode,nickel starting sheet as cathode,.........After electrifying,cathodes precipitate nickel,platinum group elements into the anode slime and recycled separately.Product nickel purity is 99.85%－99.99%. 　　 

     Process nickel oxide to get ferronickel and nickel by pyrometallurgy,silicate oxide ore can be smelted by pyrometallurgy,upon reduction,melting and refining to get nickel.When reduction,must strive for making nickel oxide full turn to nickel.When smelting,nickel-iron will separate from the lighter slag.Nickel content in nickel-iron depends on the selectivity capacity of the partial reduction process.Usually use coke as reductant,but also can use ferrosilicon as reductant.In order to remove impurities in the crude nickel-iron such as carbon,sulfur, phosphorus and chromium, crude nickel-iron must be refined.