In this article, a method of metal hydroxide precipitation by lime cream instead of caustic soda was introduced.It is also founded that the two-compound-mixture of gypsum and metal hydroxide in the slurry obtained after precipitation stage can be separated according to their different physical properties using Mixture Separation Process (MSP(R)) developed by ENFI.Experiments results indicated an effective separation of the two compounds.This technique can be applied successfully in many casesincluding precipitation of Ni, Co, Cu, Zn and Mg etc.by lime cream and subsequent MSP(R) of their hydroxides from gypsum contained slurry.