METHOD AND APPARATUS FOR NEUTRALIZATION TREATMENT OF ACIDIC WASTE SOLUTION

摘要

PROBLEM TO BE SOLVED: To lower the residual ratio of fluorine ions in a waste soln. after treatment by charging alkaline earth metal hydroxide in an acidic waste soln. to selectively precipitate a fluoric acid component and charging alkali metal hydroxide in the waste soln. so as to raise the pH value thereof to neutralize a residual sulfuric acid component in a form dissolved in the waste soln. SOLUTION: In a first neutralization treatment process performing part 50, a first neutralizing agent wherein a main alkali component is alkaline earth metal hydroxide is charged in a waste soln. to be treated being an acidic waste soln. so as to selectively precipitate the fluoric acid component in the waste soln. to be treated in a form of alkaline earth metal fluoride to perform first neutralization treatment. In a second neutralization treatment process performing part 51, a second neutralizing agent wherein a main alkali component is alkali metal hydroxide is charged in the waste soln. to be treated after the completion of the first neutralization process so as to make a pH value higher than that of the first neutralization treatment process to perform a second neutralization treatment process for neutralizing the sulfuric acid component remaining in the waste soln. to be treated in a form dissolved in the waste soln. as alkali metal sulfate.