PROCESS FOR PRODUCING MAGNETIC RECORDING IRON HYDROXIDE

摘要

Process for preparing ferric hydroxide from waste water with ferrous chloride is described. Thus, i)waste water with ferrous chloride is added with iron scrap or powder to eliminate Fe+3 and hydrogen chloride from waste water, ii)the obtained solution is added with iron scrap to give a colloidal sludge which contains ferric hydroxide with a concentration of 100mg-1,000mg/L, iii)the colloidal sludge is stirred slowly to give a high dencity ferrous chloride solution, iv)the ferrous chloride solution is reacted with alkali at 40-60 deg.C to givea high dencity ferric hydroxide.