| 摘要 |
The method is applied in the paper industry. A cyclic process is acquired by means of phosphogypsum re-crystallization ,a fine-disperse product in ordinary conditions is separated directly without grinding. By this method, the initial phosphogypsum is treated with a 40-50 percent solution of ammonium sulphate. The result of this interaction is a binary salt, which is filtered and decomposed with water and/or rinsing waters, containing up to 10 percent weight of ammonium sulphate, the ratio being solid phase / liquid phase from 1:1 to 1:2.5 at a temperature from 20 to 70 degrees C for 10 to 40 minutes. The rinsing waters used, have up to 10 weight percent of ammonium sulphate. The suspension obtained is filtered, the separated solid phase of the phosphogypsum is rinsed with water. The filtrate , containing up to 10 percent weight of ammonium sulphate is returned for repulpation of the binary salt. The filtrates from the separation of binary salt and phosphogypsum are combined and returned to the technological cycle for processing of new quantities of initial phosphogypsum.
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