(沈陽(yáng)理工大學(xué) 環(huán)境與化學(xué)工程學(xué)院，沈陽(yáng) 110159)
摘 要: 以紅土鎳礦濕法提鎳后的廢液(含(NH4)2SO4的MgSO4溶液)為原料、氨水為沉淀劑、在無(wú)分散劑條件下采用水熱法制備了片狀顆粒組成的六方晶系花狀Mg(OH)2，并研究了花狀Mg(OH)2對(duì)Cu2+、Ni2+吸附性能的影響。結(jié)果表明：在Mg2+濃度2.0 mol/L、Mg2+與NH4OH摩爾比1:0.5、水熱溫度120 ℃、反應(yīng)時(shí)間2 h的條件下合成了形貌完美的花狀Mg(OH)2。花狀Mg(OH)2去除重金屬離子Cu2+、Ni2+的能力良好。在50 mL、Cu2+和Ni2+濃度200 mg/L的溶液中分別添加200和300 mg花狀Mg(OH)2，吸附時(shí)間6 min后，Cu2+和Ni2+的去除率即可達(dá)到94.10%和95.46%。表明花狀氫氧化鎂是重金屬離子的高效去除劑。吸附機(jī)理研究表明，吸附過(guò)程為單分子層吸附，符合Langmuir模型，吸附動(dòng)力學(xué)遵從擬二階動(dòng)力學(xué)模型。
關(guān)鍵字: 紅土鎳礦；花狀Mg(OH)2；吸附；Cu2+；Ni2+
（School of Environmental and Chemical Engineering, Shenyang Ligong University, Shenyang 110159, China）
Abstract:Employing waste solution after precipitating nickel from nickel laterite hydrometallurgy (MgSO4 solution containing (NH4)2SO4) using raw material and ammonia water as precipitant, hexagonal flower-like Mg(OH)2 was successfully prepared by hydrothermal process without dispersant, which is composed of many ultra-thin sheets. Flower-like Mg(OH)2 with perfect morphology can be obtained under the conditions of Mg2+ concentration 2.0 mol/L, molar ratio of Mg2+ and NH4OH 1:0.5, hydrothermal temperature 120 ℃, reaction time 2 h. Flower-like Mg(OH)2 exhibits good adsorption ability for Cu2+ and Ni2+. The removal rate of Cu2+ and Ni2+ reach 94.10% and 95.46% in 6 min by adding 200 and 300 mg of flower-like Mg(OH)2, respectively, into 50 mL solution with Cu2+ and Ni2+ concentrations of 200 mg/L, indicating flower-like Mg(OH)2 is a highly effective remover for heavy metal ions. Further studies on adsorption mechanism show that the adsorption characteristic as monolayer was well fitted by the Langmuir model. The adsorption of heavy metal ions was adjusted by the pseudo-second-order kinetic model.
Key words: nickel laterite; flower-like Mg(OH)2; adsorption; Cu2+; Ni2+
