染料残渣焚烧过程中HCl的排放特征及其对重金属形态转化的影响

HCl Emission and Its Influence on the Transformation of Heavy Metals'Speciation During the Incineration of Dyestuff Residue

通过对危险废弃物染料残渣小型管式炉的焚烧实验以及热力学平衡计算,研究了染料残渣焚烧过程中HCl的排放特征、氯对重金属形态归趋的影响以及3种脱氯剂高温脱氯效果预测等内容。研究结果表明:温度是HCl排放的决定因素,生成的HCl主要来自于染料残渣中有机氯;工况在500～900℃之间,氯对Hg、Pb、Cu和Ni的归趋形态主要贡献分别为HgCl_2(g)、PbCl_4(g)、PbCl_2(g)、(CuCl)_3(g)、NiCl_2(s)和NiCl_2(g);3种脱氯剂中CaCO_3高温脱氯稳定性最好,在800℃以下基本没有HCl析出,Fe_3O_4高温脱氯稳定性最差。

Dyestuff residue, a type of hazardous waste, is incinerated in the tubular furnace, and thermodynamic equilibrium model is used to calculate and analyze the chlorine behavior. The HCl emission and its effects on the behaviors of heavy metals are studied. Meanwhile, the effects of three dechlorine reagents are predicted at high temperature. Results show that HCl emission is dependent on incineration temperature. The HCl evaporated mainly derives from the organic chlorine. Under the working condition of 500-900℃, the main products of Hg, Pb, Cu, Ni, Zn, and Mn in reaction with HCl are HgCl2（g）, PbCl4（g）, PbCl2（g）, （CuCl）3（g）, NiCl2（s） and NiCl2（g）, respectively. Among the three dechlorine reagents, CaCO3 is optimal to remove chlorine at high temperature---little of HCl is released below 800℃, whereas Fe304 is unstable at high temperature.