Comprehensive utilization method for laterite-nickel ore

The invention relates to an environmental-friendly comprehensive utilization method for a laterite-nickel ore, which comprises the following steps of: (1) grinding the laterite-nickel ore, mixing with sulfuric acid, roasting, dissolving out roasted clinker and filtering to obtain silicon dioxide and dissolution liquid; (2) deironing the dissolution liquid to obtain liquid No.2 and filter residue (iron compounds), wherein the liquid No.2 comprises aluminum, nickel and magnesium and can be treated by the step (3) or (4); (3) precipitating the aluminum in the liquid No.2 by using alkali, filtering, precipitating the nickel in filtrate by using sodium sulfide, filtering, precipitating the magnesium by using the alkali, and treating filter residue to obtain aluminum oxide, nickel hydroxide, nickel sulfide and magnesium oxide respectively; and (4) precipitating the aluminum and the nickel in the liquid No.2 by using the alkali, treating mixed slag containing the aluminum and the nickel by using the alkali to obtain aluminum hydroxide and nickel hydroxide products, and precipitating the magnesium in filtrate subjected to aluminum and nickel precipitation by using ammonia or ammonium saltto obtain a magnesium oxide product. The method is suitable for treating various laterite-nickel ores, three wastes (waste gas, waste water and waste residue) are not generated, and valuable components magnesium, nickel, iron, aluminum and silicon in the laterite-nickel ore are separated and extracted.