| 摘要 |
1,127,247. Defluoridating phosphoric acid. EERSTE NEDERLANDSCHE COOPERATIEVE KUNSTMESTFABRIEK. 23 Nov., 1965 [30 Nov., 1964], No. 49784/65. Heading C1A. Fluorine compounds are removed from phosphoric acid by heating the acid in the presence of one or more synthetic and/or natural silicates of the second and/or third group of the periodic system. The silicate may be aluminium silicate or magnesium silicate, e.g. sepiolite, serpentine or preferably talc with a particle size below 30 Á added in the amount of 10-20 g./l. of the phosphoric acid. The latter may contain 800-1000 g. P 2 O 5 /l. The heating may be from 60-80‹ C. The acid may be preconcentrated to a 55% wt. P 2 O 5 content. A gas such as air may be passed through the acid during heating. |
