Chan C C, Kirk D W
Department of Chemical Engineering and Applied Chemistry, University of Toronto, Ontario, Canada.
J Hazard Mater. 1999 Jan 1;64(1):75-89. doi: 10.1016/s0304-3894(98)00227-1.
A total elemental analysis was performed on a municipal solid waste (MSW) fly ash sample, before and after it was treated at 1000 degrees C, to reveal the metal distribution between the volatile matter and the ash residue. Metals such as Pb, Zn, Cd, and to a lesser degree, Cr, Mn and Ni, were volatilized. Addition of chlorinating agents generally increased the volatility of certain elements. More acid resistant compounds were formed in the ash residue after the heat treatment using CaCl2 as a chlorinating agent. The efficiencies of volatilization of the metals, using Cl2 as a chlorinating agent, were generally higher compared with using CaCl2. However, CaCl2 was found to be a more selective chlorinating agent for volatilizing the heavy metals of concern, i.e., Pb, Cd, Zn and Cu. The efficiencies of volatilization of the recovered metals were approximately proportional to their standard free-energy changes (delta G(o) for the corresponding chlorination reactions.
对城市固体废物（MSW）飞灰样品在1000摄氏度处理前后进行了全元素分析，以揭示挥发性物质和灰渣之间的金属分布。铅、锌、镉等金属以及程度稍低的铬、锰和镍会挥发。添加氯化剂通常会增加某些元素的挥发性。使用氯化钙作为氯化剂进行热处理后，灰渣中形成了更多耐酸化合物。与使用氯化钙相比，使用氯气作为氯化剂时金属的挥发效率通常更高。然而，发现氯化钙是一种更具选择性的氯化剂，用于挥发所关注的重金属，即铅、镉、锌和铜。回收金属的挥发效率与其相应氯化反应的标准自由能变化（ΔG⁰）大致成正比。
