Effects of reaction temperature and reaction time on phosphorus conversion were investigated using silica and potassium feldspar as flux agents. The results show that phosphorus conversion with K-feldspar was higher than that of silica. Thermodynamics and kinetics of the phosphate rock reduction process were studied by HSC-5 thermodynamics software and thermogravimetric analysis (TGA). The results demonstrate that when using K-feldspar, the operating temperature of yellow phosphorus and the activation energy is 215 oC and 3.2 kJ.mol-1 lower than that of silica, respectively, which indicates that K-feldspar can save energy and reduce cost. The residue was analyzed by XRD. The results indicate that K-feldspar as a flux agent is better than silica. The reason is mainly because K-feldspar decomposition can release highly reactive SiO2, and Ca5(PO4)3F can be decomposed at low temperature. Moreover, alkali metals are involved to lower eutectic formation temperature which facilitates main reactions.%分别使用硅石、钾长石作为助熔剂,考察反应温度,反应时间对磷转化率的影响.结果表明:钾长石助熔时磷的转化率明显高于硅石.利用HSC-5热力学软件及热重(TGA)分析方法,分别考察了磷矿碳热还原过程的热力学及动力学过程.结果表明:钾长石与硅石助熔相比,黄磷生产操作温度可降低215℃,钾长石助熔时的活化能降低了3.2 kJ.mol-1,具有较好的节能降耗效果.残渣XRD分析表明:钾长石助熔优于硅石的主要原因是钾长石分解释放物SiO2反应活性高,Ca5(PO4)3F可在较低温度下发生脱氟反应,同时因有碱金属参与造渣,低共熔物形成温度低,便于主反应的进行.
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