| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a method for producing a coagulant where an aluminum sulfate solution is a raw material and the defects of the aluminum sulfate solution are overcome and to provide the coagulant.SOLUTION: Shell powders and calcium carbonate as a coagulant aid are charged into pure water stored in a first tank and sufficiently agitated and mixed with an agitator. The shell powders and calcium carbonate are dissolved by charging an aluminum sulfate solution (preferably aluminum sulfate) from a second tank into the first tank and by violent agitation and then an obtained solution is gelatinized (step S30) by standing for a proper time after stopping the agitator at the first tank. An obtained gel is dissolved again (step S40) by charging diluted hydrochloric acid from a third tank into the first tank.</p> |
