Vapor Pressure Measurements of heavy Metal Component in Molten Slag and Incinerator Residue by Transpiration Method Using Vertical Volatilization Chamber

作为开发有效工艺的基础，通过挥发消除熔渣和焚烧炉残渣中的铅、砷和锑等有害成分，这些组分的蒸汽压和活度系数数据具有重要的实际意义。因此，本研究开发了一种利用垂直挥发室进行蒸腾的方法，测定了PbO-FeO_2-FeO_2-CaO-SiO_2和PbO-ZnO-FeO_&SiO_2熔渣中PbO的蒸汽压，以及CaO-SiO_2-FeO_&lt；1.5&gt；，SbO_&lt；1.5&gt；炉渣是在1150-1300℃测定的。在这些数据的基础上，得出了渣中各组分的活度系数。对于所研究的任何渣，PbO的活度与Raoultian行为呈负偏差，PbO的活度系数在渣中PbO的摩尔分数为0.5时出现最小值。结果表明，随着炉渣碱度的增加，PbO的活度系数增大。用热力学数据对渣中PbO的析出进行了热力学分析，认为PbO单体在气相中占优势，而As_4O_6和Sb_4O_6则分别为As_4O_6和Sb_4O_6。在此基础上，讨论了这些重金属组分在炉渣和焚烧炉残渣中的挥发行为。

As fundamentals for developing an efficient process to eliminate detrimental components such as lead, arsenic and antimony in the molten slag and incinerator residue by means of volatilization, the data on vapor pressure and activity coefficient of these components are of practical importance. Hence, in the present study, a transpiration method using a vertical volatilization chamber was developed and the vapor pressure of PbO in the liquid PbO-FeO_<1.5>-CaO-SiO_2 and PbO-ZnO-FeO_<1.5>-CaO-SiO_2 slags and those of SbO_<1.5>, SbO_<2.5> and AsO_<2.5> in the liquid CaO-SiO_2-FeO_<1.5> slags were determined at 1150-1300℃. On the basis of these data, the activity coefficients of these components in the slag were derived.For any slag investigated, the activity of PbO was found to present a negative deviation from the Raoultian behavior and the activity coefficient of PbO showed a minimum value at the mole fraction of PbO in the slag with about 0.5. It was found that the activity coefficient of PbO increased with increasing basicity of slag. It was also clarified that the activity coefficient of PbO in the slag with ZnO was smaller than that in the slag without ZnO.The gas species evaporated from the slags were evaluated using the obtained thermodynamic data and it was suggested that the PbO monomer is prevailing in the gas phase while As_4O_6 and Sb_4O_6 prevail for arsenic oxide and antimony oxide, respectively. Thus, the volatilization behavior of these heavy metal components in the slag and incinerator residue was discussed on the basis of the obtained data.