Reaction Mechanism Process Analysis with Phosphogypsum Decomposition in Multiatmosphere Control

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• 作者：Xiaodan Yan ; Liping Ma ; Bin Zhu ; Dalong Zheng ; Yan Lian
• 刊名：Industrial & Engineering Chemistry Research
• 出版年：2014
• 出版时间：December 17, 2014
• 年：2014
• 卷：53
• 期：50
• 页码：19453-19459
• 全文大小：518K
• ISSN：1520-5045

文摘

This paper proposes a two-step method for phosphogypsum (PG) decomposition by circulating various atmospheres instead of a single atmosphere. To achieve a high concentration of CaO in the final product, the PG was decomposed in reducing atmosphere with CO (99.99%) at rising temperature until the mass loss changes stably in the first step reaction. For the second-step reaction, the atmosphere was changed from a reducing atmosphere to an oxidizing one of air at a constant temperature. With different final constant temperatures, the analysis of thermogravimetric analyzer (TGA) and Factsage6.1 Reaction and Phase diagram module indicated that the purity of CaO improved in repeating atmosphere after 1000 掳C, which was proved by the XRD analysis. Especially, the final product is almost entirely CaO in 1100 掳C when compared with other temperatures. The kinetic mechanism model of CaS oxidization was established using the Kissinger, Flynn鈥揥all鈥揙zawa, and Coats鈥揜edfern methods.