A Recovering Method of Valuable Ingredients In the Pickling Waste Acid From STS Work

摘要

PURPOSE: A recovering method of valuable ingredients from waste pickling solution used in STS work is provided, which is characterized in that valuable ingredients in waste pickling solution are recovered in order with varying pH conditions. CONSTITUTION: The method includes the steps of adding a slag leachate with a hydrogen-ion concentration of greater than pH 12 to waste pickling solution used in STS work so that Fe(OH)2 is precipitated at pH 3 to 4; after separation of Fe(OH)2, adding the slag leachate more to the waste pickling solution for the precipitation of chromium hydroxides in the range of pH 5.8 to pH 6.5; after separation of chromium hydroxide, adding the slag leachate more to the waste pickling solution for the precipitation of nickel hydroxides in the range of pH 7 to pH 8; after separation of nickel hydroxides, adding the slag leachate more to the waste pickling solution for the precipitation of manganese hydroxides in the range of pH 8 to pH 9.5.