Abrasion-resistant sodium perborate monohydrate with high bulk density and dissolution rate and process for its preparation

摘要

The process concerns the prodn. of Na perborate monohydrate (I) in the form of a granulate (IA) with (a) an active oxygen content (Oa) of at least 14 wt.%, (b) a bulk density to ISO 3424 of at least 600 g/l, (c) an attrition index to ISO 5937 of less than 8% and (d) a 95% dissolution time of less than 2 min. for an amt. of 2 g/l in water at 15 degrees C. The process comprises spraying (I) particles, which are smaller than the granulate to be produced, with an aq. (I) soln. in a fluidised bed at 40-95 degrees C and simultaneously evaporating water. The (I) soln. used is prepd. by supplying and mixing aq. H2O2 soln. with aq. NaBO2 soln. and the contact time between supplying the solns. and spraying is at least 2 s.