METHOD OF FREE HYDROXYLAMINE AQUEOUS SOLUTION PREPARING Russian patent published in 2002 - IPC

FIELD: chemical technology. SUBSTANCE: invention relates to preparing aqueous solutions of hydroxylamine no containing metal ions. Method of preparing free hydroxylamine an aqueous solution involves treatment of hydroxylammonium salt with ammonia or ammonium hydroxide by countercurrent in a stripping tower that results to release of hydroxylamine and the obtained solution is subjected for distillation fractionation for hydroxylamine an aqueous solution and salt fraction simultaneously. The claimed method is carried out simple under mild conditions under pressure from 5 to 300 kPa in a stripping tower and from 1 to 200 kPa in a distillation column. Method is characterized by a nonsignificant thermal loading, low concentration of hydroxylamine and short time stay in a process that provides a minimal danger of decomposition that is estimated to be about 4.4 wt.%. The yield of hydroxylamine is about 94 wt.%. EFFECT: improved method of preparing, increased yield. 11 cl, 2 dwg, 3 ex