PRODUCTION OF SODIUM PERBORATE MONOHYDRATE BY FLUIDIZED-BED DEHYDRATION

Sodium perborate monohydrate is used in the formulations of concentrat ed detergents and some medical, disinfectant, and cleaning preparation s. Sodium perborate monohydrate (NaBO3 . H2O or NdBO2 . H2O2) contains 16% active oxygen. It does not have a specific melting point. When he ated, it decomposes by releasing oxygen and water. Sodium perborate mo nohydrate is preferred to tetrahydrate due to its higher oxygen conten t and faster dissolution rate. In addition, in storage, monohydrate is more stable than tetrahydrate. Sodium perborate monohydrate is produc ed commercially either by dehydration of tetrahydrate or by crystalliz ation of monohydrate. In this work sodium perborate tetrahydrate is de hydrated in a fluidized-bed dehydrator at 100-180 degrees C with about 0.5 h retention time. The product obtained was pure and had the desir ed bulk density and active oxygen content. Its dissolution rate was hi gh, and it had good properties of storage and resistance to dusting. D uring dehydration when dry air was used, dehydration temperatures of 1 45-150 degrees C and a retention time of 0.5 h were found to be suitab le for the production of monohydrate with an active oxygen content of 15.6% and bulk density of 0.5-0.6 g/cm(3).