Solubility and Modeling of Sodium Aluminosilicate in NaOH–NaAl(OH)4 Solutions and Its Application to Desilication
Solubility and Modeling of Sodium Aluminosilicate in NaOH–NaAl(OH)4 Solutions and Its Application to Desilication
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DOI：
10.1021/ie301590r
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发表时间：
2012-11
影响因子：
4.2
通讯作者：
Lan-mu Zeng;Zhibao Li
中科院分区：
文献类型：
--
作者：
Lan-mu Zeng;Zhibao Li
测定和模拟了拜耳法脱硅的主要产物钠铝硅酸钠在NaOH和NaOH-NaAl(OH)(4)溶液中的溶解度。在间歇结晶器中合成了34.4K的铝硅酸钠，考察了温度、溶液浓度和陈化时间对其的影响。溶解度随NaOH浓度的增加而增加，随Al(OH)(3)的加入而急剧下降，在0.8mol.L-1左右达到最小值，然后增加，借助OLI平台通过回归建立了方钠石溶解度的混合溶剂电解质模型。此外，还对NaOH-NaAl(OH)(4)溶液以方钠石为晶种的脱硅动力学进行了实验研究，并用二级动力学模型进行了模拟。在323.2-363.2 K温度范围内脱硅的活化能为92+/-14kJ.mol(-1)。在最佳操作条件下，反应2 h后可脱除80%的二氧化硅。
The solubility of :sodium aluminosilicate (sodalite), a major desilication product (DSP) in the Bayer process, in NaOH and NaOH-NaAl(OH)(4) solutions was determined and modeled from 3.03.2 to 34 4 K Sodium aluminosilicate was synthesized in a batch crystallizer and the effect of temperature, solution concentrations, and aging time Was investigated. Solubility was found to increase with increasing NaOH concentration while the solubility sharply decreases with the addition of Al(OH)(3), reaches a minimum at about 0.8 mol.L-1, and then increases A mixed-solvent electrolyte (MSE) model for the solubility of sodalite was developed with the help of the OLI platform via regression to obtain the model parameters. In addition, the desilication kinetics of NaOH-NaAl(OH)(4) solutions by using sodalite as seeds was studied experimentally and modeled with the aid of a second order kinetic model. The activation energy of desilication over the temperature range 323.2-363.2 K was found to be 92 +/- 14 kJ.mol(-1). Under the optimal operation conditions, 80% silica was removed after 2 h.