Study On Low Degree Nickel Laterite Ore With Reduction Roasting-diluted Hydrochloric Acid Leaching Process

The thesis provides a new method to carry out the laterite nickel ore via coalreduction roasting-dilute hydrochloric acid leaching method, which can recover theiron when extracting the nickel and cobalt, achieve to the recycling use of availelement of lateritic ore in particular low grade lateritic ore. And the effect of theselective coal reduction roasting treatment for laterite nickel ore on acid leachingprocess, and the hydrochloric acid leaching process of reductive-laterite nickel ore areinvestigated in this paper.The reduction roasting and acid leaching process were investigated, the resultsshow that, the nickel and cobalt can be transferred into Ni2+and Co2+while the ironcan be transferred into Fe3O4by controlling the reduction degree of iron and the acidleaching factors.The laterite nickel ores were processed by the activation-chloride roasting methodand direct coal reduction roasting method, respectively. The ores were heated for60min at600°C followed by chloride roasting with1mol/L HCl for60min at500°C.At the same time the ores were heated for60min at700°C, mixed with10%coal.Then the preprocessed ores were leached with1mol/L HCl for60min under80oC atliquid-solid ratio5:1(mL/g) and determined the pre-treatment technology. Finally,taking the laterite processed by reduction roasting process as raw materials, the acidleaching behavior of reductive-laterite nickel ore was studied, and the experiment wasresearched using the industrial waste acid as leachant. The results show that:(1) The laterite nickel ores are heated for60min at700°C, mixed with10%coal,then leaching with hydrochloric acid can realize the leaching efficiency of Ni, Co, Feand Mn is87.37%,88.23%,14.83%and42.98%, respectively, which is higher thanthe leaching efficiency with activation-chloride roasting-acid leaching.(2) Under the conditions of1mol/L HCl, leaching temperature80°C, leachingtime1h, stirring speed300r/min, liquid to solid ratio10:1(mL/g), leachingefficiency of Ni, Co, Fe and Mn is89.93%,>90%,30.48%and55.91%, respectively.(3) Using the industrial waste acid as leaching agent, after leaching for60min at80oC, the leaching efficiency of Ni, Co, Fe and Mn is89.41%,>90%,24.30%and 49.76%, respectively. Using waste acid as leaching agent, not only achieve theextraction of nickel and cobalt and the deposition of iron, but also realize therecycling steel waste acid and savings cost. Above all, this process is a green processwhich can realize the circular using of resource.