China Nonferrous Metallurgy

The high-pressure acid leaching process used to treat laterite-nickel ore with low content of magnesium oxide. The Ni can be precipitated with the hydroxides or sulfides from the leaching solution after Fe&Al removing. This paper proposes to use calcium hydroxide as a precipitant, combined with alkali activation controlling technology, under the appropriate calcium hydroxide dosage coefficient, to study the properties of the precipitation products, nickel cobalt hydroxide and calcium sulfate, under different activation times. Finally, it is determined that the best activation time is 3~4min. At this time, the precipitation rate of nickel can reach more than 80%, and the physical properties of calcium sulfate are also suitable for the subsequent separation process.