| 摘要 |
1324363 Sodium and potassium tripolyphosphates ALBRIGHT & WILSON Ltd 16 July 1970 [30 July 1969] 38159/69 Heading C1A An alkali metal tripolyphosphate is prepared by forming an aqueous solution of sodium or potassium orthophosphate having a concentration between 10 and 40% P 2 O 5 by weight and an atomic ratio of alkali metal to phosphorus such that it is capable of forming at least a substantial proportion of tripolyphosphate upon calcination; spray drying between 1/6 and 5/6 of this solution to form a dry mixture of orthophosphates; calcining the mixture in a rotary kiln at 200‹ to 600‹ C. until the orthophosphates have been converted to tripolyphosphate having a bulk density of from 0À4 to 0À5 specific gravity; cooling this tripolyphosphate and mixing it with the remainder of the aqueous solution of orthophosphates, the cooling being such that the mixture of tripolyphosphate with orthophosphate is at less than 120‹ C.; and heating the mixture in a rotary kiln at from 200‹ to 600‹ C. until the remainder of the orthophosphates has been converted to tripolyphosphate product. |
