Immobilization of Electroplating Sludge by Lead-Zinc Smelting Slag-Based Cementitious Material
Electroplating sludge(ES)is a hazardous waste containing various heavy metals.This study aims to evaluate the solidification effectiveness of a geopolymer material prepared from lead-zinc smelting slag(LZSS)on electroplating sludge and elucidate the impact mechanism of organic polymers on this process.The results demonstrate that under the conditions of3.5％(mass fraction)alkali content,a water glass modulus of 1.4,and a liquid-to-solid ratio of 0.22,the lead-zinc smelting slag-based geopolymer material can safely immobilize2.5％(mass fraction)electroplating sludge.The addition of organic polymers enhances the immobilization amount of composite geopolymer material twofold and increases the compressive strength by 27.45％.At this stage,the total leaching concentration of Cr decreases from 20.05 mg/L to 13.65 mg/L,which is lower than the limit specified in the Identification Standards for Hazardous Wastes-Identification for Extraction Toxicity(GB 5085.3-2007).Mineral composition analysis,microstructure observation,chemical bond analysis,and oxidation state characterization of the solidified matrix indicate that the combined effect of Fe(Ⅱ)in the lead-zinc smelting slag and organic polymers effectively reduces the toxicity of Cr and enhances the fixation rate of heavy metal ions.This study provides a new approach to the safe disposal and comprehensive utilization of electroplating sludge and lead-zinc smelting slag.
lead-zinc smelting slagelectroplating sludgeorganic polymercompressive strengthheavy metal immobilization
万方数据
维普
