不同基质材料及气氛对砷的静态高温挥发影响

Effect of different cementbased materials on arsenic volatilization at high temperature based on static state

采用自制的静态实验装置,将重金属试剂As_2S_3以不同比例分别添加到石英砂、石粉及水泥生料中,然后在100~1 400℃焚烧温度下持续加热60 min后,以空气、氮气和配制的标气作为不同气氛介质,分别测定固体特性以及气体中的重金属浓度。结论如下:随着温度的升高,砷的挥发率也逐渐升高。同一温度下,石英砂、石粉及水泥生料对砷的固化率比较,生料粉>石粉>石英砂;在有钙存在时,高温条件反而有利于砷的固定。600~1 400℃,生料粉与重金属生成了Ca_(54)MgAl_2Si_(16)O_(90)等化合物。

Using the self-made experimental device, the heavy metal reagent As：S3 added into the quartz sand, stone powder and cement raw meal, and then were heated at 100-1 400% for 60 min under different atmosphere like air, nitrogen, and configuration standard gas respectively to test the concentration of heavy metals in the gas and solid characteristics. The results showed that the volatilization rate of arsenic was increased with the increasing of temperature. At the same temperature, the solidification rate of arsenic in quartz sand, stone powder and cement raw meal was compared. The result was that raw meal 〉 stone powder 〉 quartz sand. When calcium was present, the high temperature condition was beneficial to the stabilization of arsenic. From 600 ℃ to 1 400 ℃, raw meal and heavy metals form compounds such as Ca54MgAL2Si16O90 et al.