| 摘要 |
A process for the manufacture of monopotassium phosphate of a high purity without utilizing organic solvents. Monopotassium sulfate is reacted, at a temperature in the range of 40 to 100 DEG C with a phosphate constituent selected from phosphate rock, dicalcium phospate or mixtures thereof in the presence of phosphoric acid. The common metal impurities, organic matter and fluorides present in the starting phosphate rock are substantially eliminated, with the calcium sulfate resulted thereto. After separating out the calcium sulfate, the filtrate is neutralised to a pH in the range of 3 to 7, with a calcium-containing compound comprising Ca(OH)2, CaO or CaCO3, or mixture thereof. From the filtrate obtained, pure monopotassium phosphate is crystallised out. |
