Purification or Refining

The metal extracted by any of the above method is not completely pure and is known as Crude Metal. The metal extracted still contains some impurities are:–

·                     Other metals originally present in ore.

·                     Unreduced oxides or sulphides of metal.

·                     Residual slag or flux

·                     Non-metals like carbon, silicon, phosphorous etc.                 

                     The process of removal of impurities from the crude metal is known as Refining. The method used for refining of the metal depend upon the nature of impurities.