Nickel recovery from magnesium-rich lateritic ores - comprises leaching with sulphuric acid and converting magnesium sulphate to magnesium oxide and sulphur di:oxide

摘要

Process novelty is in (a) evaporating the MgSO4-contg. soln., at least partly, and sepg. the crystallised MgSO4.7H2O; (b) heating the sepd. MgSO4.7H2O in a reducing atmos., to form SO2, steam and MgO, and (c) converting SO2 discharged to H2SO4, which is recycled to the leaching step. MgO obtd. as by-prod. can be sintered to magnesite or used in part to neutralise the leaching soln. The mother liquor obtd. in the partial evapn. of the MgSO4-contg. soln. is recycled to the leaching step.