The  Linch  unit  that  is  managed in four shifts , operates  to produce Zinc sulfate solution
 containing  Zinc sulphide  where the percentage of impurities is minimized .
 Linch  operations  are carried out in three stages :
A) Dissolving or leaching
B) Hot Purification
C) Cold Purification
 After  cold &  hot  purification , the resulting  solution  of  Zinc sulfate is free of  impurities .   It is called Makeup .It is then analysed  and the quality control unit ensures the absence of  interfering elements added to  the electrolysis  unit .