Production manner null of high purity molybdenum Acid ammonium

摘要

PURPOSE:To easily obtain the title hexagonal columnar crystal useful as electronics industrial material, having excellent filtrability and washability, by treating an aq. sol. of molybdic acid contg. ammonium ion under a specified condition. CONSTITUTION:Insoluble matters are removed by dissolving Mo raw material (e.g. MoO3) with any of acid, alkali and water (e.g. aq. NH3) according to its chemical property, so as to take the condition of formula I-III (where, T means 'total') and thereafter, the aq. acid soln. of molybdic acid contg. ammonium ion, regulated the pH value to =2 by adding aq. NH3 or acid (e.g. HNO3) is obtd. Then, the aq. soln. is heated up to =60 deg.C to separate the crystal and heated for a fixed time to grow the crysal, and the crystal is filtered and washed to obtain the title crystal having =0.001ppm concn. of U/Mo.