Experimental Studies on Phase Transformation during Pyrite Concentrate Oxidation under Circulating Fluidized Bed (CFB) Roasting Conditions

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• 作者：Tao Wang ; Hai Zhang ; Qing Liu ; Hairui Yang
• 刊名：Industrial & Engineering Chemistry Research
• 出版年：2011
• 出版时间：December 21, 2011
• 年：2011
• 卷：50
• 期：24
• 页码：14168-14174
• 全文大小：945K
• 年卷期：v.50,no.24(December 21, 2011)
• ISSN：1520-5045

文摘

The phase transformation during pyrite concentrate oxidation under the conditions of the circulating fluidized bed (CFB) roasting process was experimentally studied at temperatures of 600鈥?00 掳C, O₂ concentrations of 1%鈥?1%, and particle residence times of 5.0 s in a drop tube furnace (DTF). The X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to analyze the phase composition and microstructure of the product samples. For the roasting process with a short residence time, the products of pyrite concentrate oxidation are in a nonequilibrium phase. At higher O₂ concentration and temperature, Fe₃O₄ is the dominant product phase. When O₂ concentration increases, the micromorphology of sample products tends to be perfectly spherical particles with smooth surface, difficult for the formed Fe₃O₄ to be oxidized to Fe₂O₃. Experimental results indicated that, in the CFB roasting, relatively high temperature and low O₂ concentration are needed to control the phase transformation into Fe₂O₃.