Recovery of Magnesium and Recycling of Spent Solution in Chloride-Based Atmospheric Acid Leaching of Nickel Laterite

摘要

In this work, the equilibrium relationship of MgCl_2-MgSO_4-HCl-H_2SO_4-H_2O system at 75°C was studied. This system is ofinterest because of its relevance to the process designed forrecovery of magnesium and recycling of spent solution inchloride-based atmospheric acid leaching of nickel laterite.Experimental results showed that the concentration of Mg~(2+) iondecreases with the increase of H~+ ion concentration whenmSO_4~(2-)/(0.5m_(Cl~-)+mSO_4~(2-))is the same. With the same H~+concentration, the concentration of Mg~(2+) ion decreases sharply atfirst and then increases slightly when mSO_4~(2-)/(0.5m_(Cl~-)+mSO_4~(2-)changes from 0.1 to 1. And in all experiments, MgSO_4·H_2O wasthe only crystallization phase.