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Nickel is mainly used for stainless steel, high temperature alloys, electroplating and chemical industries, has a very important position in the development of the national economy. The world, about 2/3 of the nickel used in the production of stainless steel, nickel raw material costs accounted for about 70% of the cost of austenitic stainless steel production. 60% of the world's nickel metal smelting raw materials from nickel sulfide ore, nickel sulfide mineral resources total only accounts for about 28% of the total nickel resources. With the dwindling of nickel sulfide ore, the mainly nickel oxide nickel laterite mine nickel metallurgical raw materials, the proportion is increasing day by day. The nickel laterite can be broadly divided into of limonite and humus two categories. Former high iron content, low nickel content, should adopt the high-pressure acid soaked metallurgical treatment process; latter is characterized by low iron, high silicon and magnesium, electric furnace smelting reduction is a mainstream technology. Domestic companies being developed abroad humus laterite nickel ore as raw material, Experimental study of the system to restore the melting of the step-by-step process for the production of ferro-nickel, such as drying and dehydration, roasting, smelting reduction. First, using the DTA-TG dehydration of raw materials and reduction process carried out a study to determine the various stages of the reaction process and the reaction mechanism. The study found that in the calcination temperature of 1000 ℃, basic nickel laterite moisture removal; during the restore process, part of the reduction of iron and nickel in the solid phase, while the rest is in the molten state 's. On this basis, the calcined laterite nickel ore smelting reduction experimental study. The effects of the reductant (coke powder), flux, melting temperature, melting time melting effect. The coke ratio, flux, melting temperature, melting time of the main metal recovery, grade of nickel in ferronickel and nickel iron S, P content of. The study found that, the coke ratio the most significant impact of the melting effect, while CaO as a flux more than CaCO3 ideal. Study to determine the best experimental conditions: the the coke ratio 11% CaO ratio of 8.3%, the melting temperature of 1550 ° C, the melting time of 40 min. , Ferro-nickel in nickel grade of 22% under the best conditions, nickel, cobalt recoveries were 92.5%, 70%, S, P content in the nickel-iron were 0.4% and 0.05%. Production of ferro-nickel smelting reduction process has the advantages of process is short, easy to control nickel iron grade, metal recovery, acidic residue is not conducive to the removal of S, P, need to be further refined nickel-iron alloy.
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