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研究了MnO2离子筛的制备、表征及其提锂性能。通过控制低温水热合成反应条件制备了4种不同晶相的一维纳米MnO2,进一步用浸渍法制备了Li-Mn-O三元氧化物前驱体,并经酸处理后得到对Li+具有特殊选择性的离子筛。用XRD、吸附等温线、吸附动力学及pH滴定等手段对产物的晶相结构和Li+吸附性能进行了研究。结果表明,SMO-b和SMO-d离子筛的Li+平衡吸附量符合Freundlich吸附等温方程。反应物浓度对MnO2不同晶面的生长速率有不同的影响,但(NH4)2SO4对吸附容量并无提高。吸附速率方程符合一级动力学Lagergren方程。MnO2离子筛Li+的吸附量远远高于Na+。
The preparation, characterization and lithium extraction of MnO2 ion sieve were studied. Four kinds of one-dimensional nano-MnO2 with different crystal phases were prepared by controlling the reaction conditions of hydrothermal synthesis at low temperature. Li-Mn-O ternary oxide precursors were prepared by impregnation and treated with acid to give a special choice for Li + Sexual ion sieve. XRD, adsorption isotherms, adsorption kinetics and pH titration were used to study the crystal structure and Li + adsorption properties of the product. The results show that the equilibrium adsorption capacity of Li + on SMO-b and SMO-d ion sieves meets the Freundlich adsorption isotherm equation. The reactant concentration has different effects on the growth rate of different MnO2 crystal planes, but (NH4) 2SO4 does not increase the adsorption capacity. The adsorption rate equation conforms to the first-order kinetic Lagergren equation. The adsorption capacity of Li + on MnO2 ion sieve is much higher than Na +.