Leaching nickel and removing Fe from garnierite of transition layer nickel laterite ores

Garnierite was leached with pregnant solution of leaching limonitic by Na-jarosite precipitation.The results show that,during the process of leaching garnierite with acid,the leaching rates of Ni,Mg and Fe are 93.34%,78.28% and 26.4% under the conditions of garnierite ore size between 106 μm and 150 μm,end pH of leaching 1.3,leaching time 3 h,temperature 95 ℃ and stirring rate 150 r/min.During the process of leaching garnierite with pregnant solution of leaching limonitic,the leaching recoveries of Ni and Mg are 92% and above 74%,respectively,when the molar ratio of Na of sodium sulfate added to that of Na-jarosite precipitation is 1.3.Fe removal efficiency is more than 87%.When Fe concentration is 15.87-42.16 g/L,there is little effect on leaching recoveries of Ni and Mg.Moreover,Fe concentration is almost less than 4 g/L.