Verfahren zur Herstellung koerniger,Perborate enthaltender Salzgemische

摘要

A composition containing a perborate is obtained by spraying a solution containing a salt which crystallizes with binding water of crystallization upon a moving layer of perborate particles not dispersed in air, the quantity and concentration of the sprayed-on solution being such that the water is completely bound as water of crystallization in the salt mixture. The spraying solution, which may be saturated, may comprise borax, sodium- or potassium-carbonate, -sulphate, -ortho, -pyro or -polyphosphates and may also contain dispersed magnesium or other insoluble silicate, magnesium phosphate, magnesium soaps or metastannic acid. The perborate may be wholly or partially dehydrated. The perborate particles may be at room temperature and the spraying solution may be at 15 DEG to 95 DEG C. As shown in Fig. 1, perborate particles are supplied from a vessel 1 via a metering device 2 and funnel 3 on to an inclined rotating plate 4, the inclination of which is adjustable. A calcined salt may be supplied from a vessel 5. The aqueous solution of the salt which crystallizes with binding water of crystallization (which may be the same salt as is contained in the vessel 5) is contained in a vessel 7 maintained under pressure by means of gas supplied from a conduit 8 and is sprayed upon the perborate from a nozzle 12, the conduit 10 to which may be heated by an element 11. The granulated material runs over the rim of the plate 4 into a funnel 13 and thence by a tube 14 into a vessel 15 to which air is supplied under pressure, thus impeding the fall of the granules and aiding delivery of the granules via pipes 19 and 20 to a separator 21 which is exhausted by a fan 27. From the separator 21, fine particles are withdrawn into a cyclone 23 and are returned to the funnel 3, and the separated granules are delivered to a shaker screen 28 and are removed through a tube 29. The coarse-grained material is broken up by a mill 30 and returned to the separator 21. In a modification, the rotating inclined plate 4 may be replaced by a rotating inclined cylinder 62, Fig. 3a, to which the perborate is delivered by a funnel 61 and the salt solution by nozzles 57.ALSO:A composition containing a perborate is obtained by spraying a solution containing a salt which crystallizes with binding water of crystallization upon a moving layer of perborate particles not dispersed in air, the quantity and concentration of the sprayed-on solution being such that the water is completely bound as water of crystallization in the salt mixture. The spraying solution, which may be saturated, may comprise borax, sodium- or potassiumcarbonate, -sulphate, -ortho-, -pyro-, or -polyphosphates and may also contain dispersed magnesium or other water-insoluble silicate, magnesium phosphate, magnesium soaps or metastannic acid. The perborate may be wholly or partially dehydrated. The perborate particles may be at room temperature and the spraying solution may be at 15 DEG to 95 DEG C.