Experimental study on nickel laterite magnetic roasting and magnetic separation

摘要

Nickel metal has been widely used in the field of high-performance materials and high-tech fields with the development of economy, such as stainless steel, corrosion-resistant alloys, high temperature alloys, catalysts, and so on.Approximate 65％ of the nickel is consumed in stainless steel around the world and another 12％ is mainly applied to superalloys or nonferrous alloys, which are widely used because of their corrosion resistance.The demand of nickel metal is growing continually with the increase of stainless steel production, especially in Western Europe, Japan and Southeast Asian countries.Nickel element mainly present in the nickel sulfide and laterite nickel ore.At present, about 60％ of the nickel production is derived from nickel sulfide ore, however, 70％ of nickel metal reserves in laterite nickel ore.Therefore, it is of high significance to utilize nickel-bearing laterite ore economically and efficiently with the depletion of the nickel sulfide ore and the increasing demand of nickel metal.The low nickel high iron limonite type nickel-bearing laterite ore is used as raw material and its grade is 1.20％.Experimental process of nickel-bearing lateriteis magnetization roasting and magnetic separation.The activated carbon of-0.074mm and nickel-bearing laterite ore of-0.074mm were reduced after fully mixing grinding in micro-wave oven, the nickel oxide is reduced to metallic nickel, then the ferronickel is separated with magnetic method.The single factor of nickel laterite magnetic roasting and magnetic separation is investigated, which are roasting temperature, roasting time, the amount of carbon, magnetic excitation current.The results prove thatthe nickel grade of nickel concentrate is 4.96％ and the recovery is 80％ under the optimal condition of calcinations temperature of 1 300 °C, the carbon content of 4％, the roasting time of 70 min and the excitation current of 1A.