METHOD FOR MANUFACTURING PHOSPHORIC ACID OF HIGH PURITY FROM WASTE ACID SOLUTION

摘要

A method for preparing phosphoric acid of high purity from a waste acid solution is provided to remove effectively impurities from the waste acid solution, by refining the waste acid solution through diffusion-dialysis and solvent extraction. Aluminum is separated from waste acid containing acetic acid, nitric acid, phosphoric acid, and aluminum through diffusion-dialysis using an anion exchange membrane(S10). The diffusion-dialysis is performed on the raw acid and water having a flow rate of 43-523 ml/hr.m^2 and 130-654 ml/hr.m^2 at a temperature of 30-60°C. The acetic acid and the nitric acid are extracted from the waste acid passed by the diffusion-dialysis using one organic solvent selected from alkyl-phosphonic acid, alkyl-phosphinic acid, and akyl-phosphine oxide(S20).