中国有色冶金

Residual laterite nickel ore is an important kind of laterite nickel ore, with a high content of Mg (10%~27%). In the laterite nickel ore high-pressure leaching project, it is usually used to neutralize the pressure leaching pulp, and the concentration of sulfuric acid in the pulp is usually 30~50g/L. However, the dosage of residual ore has a great impact on the leaching rate of nickel and cobalt. In order to make better use of residual laterite nickel ore, this paper carried out conventional leaching tests and reduction leaching tests. The test results show that as the dosage of residual ore increases (liquid-solid ratio decrease), the end-point acidity gradually decreases, and the leaching rate of nickel and cobalt gradually decreases; when the grinding fineness increases, the cobalt leaching rate increases significantly; the reaction proceeds rapidly, and the leaching time could be shortened in industry; when the dosage of leaching residual ore is the same in the conventional leaching and reduction leaching tests, the leaching rate of reduction leaching nickel is 5% to 25% higher than that of conventional leaching; when the dosage of residual ore is lower, the leaching rate of reduction leaching nickel is significantly improved; when the dosage of residual ore is less than 90g/L, the reduction leaching cobalt leaching rate is higher than that of the conventional leaching; when the dosage continues to increase, the reduction leaching cobalt leaching rate will be lower than that of the conventional leaching.