Production of Sodium Perborate Monohydrate by Fluidized-Bed Dehydration

Sodium perborate monohydrate is used in the formulations of concentrated detergents and some medical, disinfectant, and cleaning preparations. Sodium perborate monohydrate (NaBO 3 ·H 2 O or NaBO 2 ·H 2 O 2 ) contains 16% active oxygen. It does not have a specific melting point. When heated, it decomposes by releasing oxygen and water. Sodium perborate monohydrate is preferred to tetrahydrate due to its higher oxygen content and faster dissolution rate. In addition, in storage, monohydrate is more stable than tetrahydrate. Sodium perborate monohydrate is produced commercially either by dehydration of tetrahydrate or by crystallization of monohydrate. In this work sodium perborate tetrahydrate is dehydrated in a fluidized-bed dehydrator at 100−180 °C with about 0.5 h retention time. The product obtained was pure and had the desired bulk density and active oxygen content. Its dissolution rate was high, and it had good properties of storage and resistance to dusting. During dehydration when dry air was used, dehydration temperatures of 145−150 °C and a retention time of 0.5 h were found to be suitable for the production of monohydrate with an active oxygen content of 15.6% and bulk density of 0.5−0.6 g/cm 3 .