Thermodynamically Analysis on Diluted Acid Leaching Process of Serpentine

The reactive activities of serpentine, various minerals Fe containing and copper-nickel sulfide minerals in concentrate with diluted sulfuric acid are thermodynamically calculated and analyzed. The results show that serpentine can easily react with diluted sulfuric acid and the MgO in it can be dissolved completely. Carbonate and silicate of iron as well as FeO in the minerals may also react with diluted sulfuric acid. Pyrrhotite (FeS) can react with diluted sulfuric acid in some extent, but pyrite (FeS_2) and iron oxide (Fe_2O_3) can not be dissolved in diluted sulfuric acid. Chalcopyrite and pentlandite are not reacted with diluted sulfuric acid. Therefore, if the main gangue in nickel-copper or precious metals concentrate is serpentine and it is difficult to be removed only by floatation, the MgO content in final concentrate could be reduced by leaching with diluted sulfuric acid.