The aim of this work was to describe the conversion of raw phosphogypsum, issued from the manufacture of H3PO4 by dissolving the phosphate rock in H2SO4, into (NH4)2SO4 and CaCO3.The thermal analysis technique was used to estimate the yield of conversion. (NH4)2CO3 or (NH4)2CO3 with excess NH4OH or (NH4)2CO3 with NH3 gas were used in the preparation of (NH4)2SO4 from phosphogypsum. The obtained samples were separated and tested by chemical and thermogravimetric analyses, infrared spectrum and X-ray diffraction and the optimum conditions of conversion were determined. The results indicated that the yield of conversion equals to 83.37 and 86.70% in case of using (NH4)2CO3 or (NH4)2CO3 with excess ammoniarespectively, while by using NH3 gas the percentage of conversion increased to 94.2% at a flow rate of 6 ml/min. Chemical analysis, infrared spectrum and X-ray diffraction patterns of the yield, (NH4)2SO4 were nearly similar to the standard sample.
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机译:How the Group Leaders of Lesson Preparation Groups Facilitate Group Learning and Reflective Practice in Chinese Public High Schools =中国公立高中的备课组长是如何引领团队学习和反思性实践的?
机译:Estudohistomorfométricodeanastomosesprináriasdecólonemcoelhos,com sem preparo intestinal Histomorfometric analysis of histonic anastomosis in rabbit with having are without or preparation preparation