PROCESS FOR PRODUCING HIGH TEST HYPOCHLORITE CAPABLE OF ADJUSTING AMOUNT OF BY-PRODUCED MOTHER LIQUOR

PURPOSE:To reduce the amt. of discarded mother liquor to zero by adjusting the amt. of produced mother liquor and to produce high test hypochlorite with high chlorine yield by changing proportion of separated slurry of dibasic calcium hypochlorite to unsatd. mother liquor optionally within a fixed weight ratio. CONSTITUTION:Liquid mixture consisting of NaOH of high concn. with mother liquor (A) saturated by with Ca(ClO)2 and NaCl is chlorinated and then separated into NaCl and filtrate (B). Then, a mixture of slurry (C) of the dibasic salt obtd. by filtering a reaction product of the mother liquor (A) with slaked lime, and the unsatd. mother liquor (D) is separated with a proportion of separation adjusted to match to the demanded amt. of the by-produced mother liquor. Then, the slurry C is mixed with NaOH and the filtrate B and chlorinated, and obtd. liquid is separated into slurry E comprising slurry E consisting essentially of NaCl crystal and slurry F consisting essentially of Ca(ClO)2 crystal, and the solid in the slurry F is separated from liquid to obtain mother liquor ( I ) and Ca(ClO)2 crystal. NaCl crystal and mother liquor (II) are obtd. NaCl crystal and mother liquor (II) are obtained from slurry E. On one hand, the rest of the remaining mother liquor is concentrated by evaporation to recover NaCl and mother liquid.