摘要 |
A method for the manufacture of phosphoric acid comprises treating calcium phosphate sources such as bone phosphate and phosphate rock with fluorosulfonic acid in the presence of a limited amount of water as catalyst whereby over 98.00% of the phosphorus is converted to volatile compounds that can be subsequently hydrolyzed. A substantial excess of fluorosulfonic acid is utilized to contact the phosphate ore as a slurry. The phosphorus products are primarily phosphorus pentafluoride and phosphorus oxyfluoride. The production of phosphorus pentafluoride is favored by up to one part of water to eight parts of ore by weight in the presence of excesses of fluorosulfonic acid. Hydrolysis of the volatile compounds gives phosphoric acid and hydrogen fluoride. Hydrogen fluoride is then recycled to react with the required sulfur trioxide to make the requirement of fluorosulfonic acid for the process. |