(2) Nickel laterite ore in nickel oxide ore has high iron content, low silicon and magnesium content, and 1-2% nickel content; while nickel silicate ore has low iron content, high silicon and magnesium content, and 1.6-4.0% nickel content. At present, the development and utilization of nickel oxide ore is mainly based on nickel laterite ore. Nickel oxide ore treatment usually adopts crushing, screening and other processes to remove large bedrock ore blocks with weak weathering degree and low nickel content in advance, and the enrichment ratio is relatively low. Because nickel in nickel oxide ore is often dispersed in gangue minerals in the same quality and shape, and the particle size is very fine, it is difficult to obtain good results by direct processing by mechanical beneficiation. The beneficiation methods mainly include hydrometallurgy and pyrometallurgy.
The extraction of nickel process generally consists of crushing, sieving, washing, gravity separation, grinding, and slurry concentration, or the nickel leaching method. The target element nickel distribution varies with the nature of the ore, mostly contained in fine-grained grades. For example, the nickel minerals of the Ramu laterite mine in Papua New Guinea are mainly enriched in fine mud of -53 μm. There are uncommon, such as Cameroon cobalt nickel manganese laterite ore, the nickel are mainly concentrated in +0. In the grain size above 3mm, the Philippine BNML nickel ore limonite + ore nickel grade above 50mm 2. 89%, the coarser the grade of ore, the higher the grade of nickel.