METHOD FOR PURIFICATION OF POTASSIUM IODIDE IN WASTE SOLUTION FROM POLARIZING FILM MANUFACTURING PROCESS

摘要

PURPOSE: A purification method of potassium iodide from Polaroid film waste water is provided to efficiently eliminate impurities from Polaroid film waste water and purify potassium iodide. CONSTITUTION: A purification method of potassium iodide from Polaroid film waste water comprises the following steps: concentrating the waste water until the concentration of the iodination potassium becomes 3-6% by using a reverse osmosis system; primary vacuum concentrating the waste water until the concentration of the iodination potassium becomes 12-20%; removing precipitates generated after cooling; vacuum concentrating the remaining solution until the concentration of the iodination potassium becomes 25-35%; removing the filtrate generated after cooling; removing the filtrate after reacting calcium hydroxide with the filtrate of the process; reacting calcium ion within the filtrate with carbonate ion and removing the created calcium carbonate; removing residual calcium ion by using weak acid cation exchange resins in the filtrate of the process; and processing activated charcoal on the filtrate filtering thereof.