PbO-FeOx-CaO-SiO2-ZnO挥发性高铅渣的挥发动力学

Volatilization Kinetics of PbO-FeOx-CaO-SiO2-ZnO Lead-bearing Slag

为揭示高铅渣的高温挥发行为,以PbO-FeOx-CaO-SiO2-ZnO为基本渣系,借助热重分析技术,建立了质量比FeO/SiO2=1.8和CaO/SiO2=0.6、不同PbO含量的高铅渣高温挥发本征动力学模型,探讨了不同PbO含量下随温度变化熔渣的挥发特性,结合挥发后熔渣物相和元素分析,揭示了高铅渣的挥发规律.结果表明,温度高于700℃时,高铅渣中PbO挥发最剧烈,造成渣成分波动导致测定结果偏差;含铅量为20wt%、温度700-1450℃的平均挥发率为18.58%;高铅渣高温挥发受三维扩散控制,影响因素为PbO和硅氧复合离子的含量.

In order to reveal the volatilization characteristics of lead-containing slag, volatilization dynamics model of lead-containing slag with mass ratios of FeO/SiO2=1.8 and CaO/SiO2=0.6 at high temperature was developed using TG technique based on PbO-FeOx-CaO-SiO2-ZnO system. The effect of PbO content on volatility in lead slag was discussed. The volatile mechanism of lead slag was revealed combined with the chemical composition analysis and element analysis of the final slag. The results showed that it was exactly the severe volatilization of PbO at 700-1450℃ that lead to the change of lead composition and the deviation of its performance. Average mass loss rate was about 18.58% of slag containing 20wt% lead at 700-1450 ℃. The process of high temperature volatilization for lead-containing slag was controlled by 3D diffusion, the factors that affect the volatile were mainly the contents of PbO and silicon oxygen compound ion.