摘要：

引入氧硅比的概念，阐述等离子体熔融玻璃化技术中玻璃体的形成机理，并且用实验加以验证。使用30 kW直流等离子体电弧炉研究影响重金属固定效率的主要因素，按照正交实验表L16 (44×23)安排实验，考察氧硅比、碱基度、重金属浓度、处理温度、处理时间、飞灰种类和物料形态共7种因素的影响作用。实验结果表明：对重金属As、Pb、Zn，处理温度和重金属浓度的影响作用最为显著，随着温度升高固定效率下降，随着重金属浓度的升高，固定效率先升高再降低，并在重金属浓度6000mg·kg^-1时出现极大值；对重金属Cr，7

关键词: 玻璃体, 重金属, 等离子体, 氧硅比

Abstract:

 Plasma technology is international advanced technology to destroy various types of hazardous wastes.The vitrified slag can form in the process of plasma treatment of inorganic wastes and effectively fix heavy metals, and its leaching rate is very low.Explained the formation mechanism of vitrified slag using the concept of silicon-oxygen ratio, and verified by experiment.Concluded that the vitrified slag can form at silicon-oxygen ratio less than 3, and crystal will grow at silicon-oxygen ratio more than 3.Find out the most important factors among 7 factors, including silicon-oxygen ratio, basicity, heavy metal contents, temperature, treating time, fly-ash types and constituents, to the heavy metal fixed efficiency using a 30 kW DC plasma arc reactor system.Concluded that the temperature and the heavy metal contents are the most important factors and directly influenced the heavy metal As, Pb and Zn fixed efficiency, the other 5 factors little effect on the heavy metal fixed efficiency.With increasing temperature, the heavy metal fixed efficiency dropped.As the heavy metal contents increases, the heavy metal fixed efficiency increased and then decreased before, and reached a maximum value at 6mg·g^-1.But all of 7 factors didn’t effect to the metal Cr fixed efficiency, the heavy metal Cr fixed efficiency are more than 85% in all experiments.The heavy metal fixed process is divided into 4 stages depend on the temperature of crucibles wall heated.80% of escape heavy metal run away at volatilization period which last 6—10 minutes from heat beginning.So how to control the heavy metals running away at volatilization period is the best way to improve the heavy metals fixed efficiency.

Key words: 玻璃体, 重金属, 等离子体, 氧硅比