REMOVAL OF DISSOLVED ORGANIC SUBSTANCE IN PURIFIED PHOSPHORIC ACID

摘要

PURPOSE:To obtain high-purity purified phosphoric acid useful as food additive and guaranteed reagent of JIS in a short time, by decomposing dissolved organic substances in purified phosphoric acid with H2O2 and bringing the purified phosphoric acid into contact with a reducing phosphorus compound. CONSTITUTION:Purified phosphoric acid having =85wt.% concentration is brought into contact with H2O2 at =100 deg.C and dissolved organic substances existing in the purified phosphoric acid are decomposed. When H2O2 concentration in the reaction solution becomes =10mg/l, the purified phosphoric acid is brought into contact with =stoichiometric amount based on H2O2 of one or more reducing phosphorus compounds selected from phosphorus of simple substance, phosphorus hydride and lower oxyacid of phosphorus.