(1. 湖南城市學(xué)院 材料與化學(xué)工程學(xué)院， 益陽(yáng) 413000；
2. 中南大學(xué) 冶金與環(huán)境學(xué)院，長(zhǎng)沙 410083)
摘 要: 以聚合氯化鋁(PAC)生產(chǎn)過(guò)程中鋁鈣粉浸出渣為原料，通過(guò)酸浸-焙燒-水熱晶化工藝制備沸石，并研究其對(duì)鋅冶煉廢水中重金屬的去除效果。結(jié)果表明：鋁鈣粉浸出渣通過(guò)酸浸-焙燒-水熱晶化過(guò)程，當(dāng)原料n(SiO2)/n(Al2O3)=2時(shí)，產(chǎn)物物相為結(jié)構(gòu)完整的A型沸石；當(dāng)原料n(SiO2)/n(Al2O3)=6時(shí)，產(chǎn)物物相為結(jié)構(gòu)完整的P型沸石。擬二級(jí)動(dòng)力學(xué)方程計(jì)算得到A型沸石對(duì)Zn2+、Cd2+的平衡吸附量分別為97.09、12.39 mg/g，P型沸石對(duì)Zn2+、Cd2+的平衡吸附量分別為57.84、10.82 mg/g。Freundlich吸附等溫線(xiàn)擬合結(jié)果表明，A型沸石和P型沸石吸附Zn2+、Cd2+機(jī)理均為非均相表面的復(fù)雜吸附。當(dāng)廢水pH為8、吸附溫度為25 ℃、吸附時(shí)間為150 min時(shí)，采用A型沸石處理鋅冶煉廢水，產(chǎn)渣量為1.1 g/L，廢水中Cu2+、Pb2+、Zn2+、Cd2+、總砷(AsT)濃度分別由1.68、13.12、147.00、15.14、4.06 mg/L降至0.06、0.05、0.52、0.03、0.01 mg/L，達(dá)到《鉛、鋅污染物排放標(biāo)準(zhǔn)》(GB 25466—2010)。
關(guān)鍵字: 鋁鈣粉浸出渣；沸石；鋅冶煉廢水；吸附
（1. School of Materials and Chemical Engineering, Hunan City University, Yiyang 413000, China;
2. School of Metallurgy and Environment, Central South University, Changsha 410083, China）
Abstract:Zeolites were prepared by the process of HCl leaching, roasting and hydrothermal crystallization using calcium aluminate leaching residues(CALR) which were generated from the production process of polyaluminum chloride, and raw their removal effect on heavy metals from zinc metallurgical wastewater were studied. The results show that, after CALR is treated through the process of HCl leaching, roasting and hydrothermal crystallization, when n(SiO2)/n(Al2O3) in raw material is 2, the product is a structurally intact Zeolite A, when n(SiO2)/n(Al2O3) in raw material is 6, the product is a structurally intact Zeolite P. According to the pseudo-second order kinetic model, the equilibrium adsorption capacities of Zeolite A and P for Zn2+ are 97.09 and 57.84 mg/g, respectively, and for Cd2+ are 12.39 and 10.82 mg/g, respectively. The fitting results of Freundlich adsorption isotherm show that the adsorption of Zn2+ and Cd2+ by Zeolite A and P is a complex adsorption on heterogeneous surface. When the wastewater pH is 8, adsorption temperature is 25 ℃, and adsorption time is 150 min, the amount of residue is 1.1 g/L, and the concentrations of Cu2+, Pb2+, Zn2+, Cd2+ and AsT in wastewater decrease from 1.68, 13.12, 147.00, 15.14 and 4.06 mg/L to 0.06, 0.05, 0.52, 0.03 and 0.01 mg/L, respectively, by using zeolite A to treat the zinc metallurgical wastewater. The water qualities reach up to the《Emission standard of pollutants for lead and zinc industry》(GB 25466—2010).
Key words: calcium aluminate leaching residues; zeolite; zinc metallurgical wastewater; adsorption
