Selective Recovery of Heavy Metals from the Leach Liquor of Municipal Waste Incineration Fly Ash
A novel process was developed to recover the heavy metals contained in the municipal waste incineration fly ash, including water-washing, acid leaching and adsorption/solvent extraction, which has the prominent advantage of using orange juicing residues as the low cost raw materials to synthesize the bioadsorbents with high efficiency to recover the valuable metals. The main parameters of washing process such as liquid/solid ratio, washing time, washing frequency were tested. The optimum conditions for water washing were also determined. Citrate acid was used for extraction of heavy metals from the water-washed fly ash, and leaching conditions such as pH, liquid/solid ratios, contact time, and temperature were investigated for their effect on the extraction percentages. The optimum metal extraction can be achieved by citrate acid were also determined. The selective recovery of elements such as Pb, Fe, P, and Zn was performed on the lab-scale, and it was shown that saponified orange juicing residue (SOJR) and phosphated orange juicing residue (POJR) gels had the excellent selective adsorption affinity for Pb and Fe, respectively, at pH around 2.0 from the leach solution. While for P, the existence of citrate anion severely had the strongly adverse effect on its adsorption onto the Zr-SOJR gel, so it is not effective for phosphate removal from the citrate leaching system. DP8R had fairly good extraction for Zn2+ions from the leach liquor. The designed process has the great potential for selective recovery of Pb, Fe and Zn from the fly ash, being low-cost, effective and environmentally benign.
fly ash acid leaching selective adsorption valuable metals.
K. Huang K. Inoue H. Harada H. Kawakita K. Ohto
Department of Applied Chemistry, Saga University, Honjo 1, Saga 840-8502, Japan School of Metallurgi Department of Applied Chemistry, Saga University, Honjo 1, Saga 840-8502, Japan
国际会议
北京
英文
198-204
2010-05-17（万方平台首次上网日期，不代表论文的发表时间）