摘要
如何将AlCl_(3)·6H_(2)O从众多组分中选择性地结晶分离是从煤矸石中提Al的关键,而AlCl_(3)·6H_(2)O在煤矸石酸浸体系中的热力学平衡数据对于结晶过程的控制至关重要。在25~85℃的温度范围内,测定了不同温度和溶液浓度下AlCl_(3)·6H_(2)O在FeCl_(3)、CaCl_(2)、KCl及KCl-FeCl_(3)溶液中的溶解度。实验发现温度对AlCl_(3)·6H_(2)O在所有溶液体系中溶解度的影响均不明显,溶解度只随温度的升高略有增加;溶液浓度是影响溶解度的主要因素,AlCl_(3)·6H_(2)O在所有溶液体系中的溶解度均随溶液浓度的升高而明显下降,分析其原因是由于溶液浓度的增大使得Cl^(–)同离子效应增强。为了提高OLI软件预测结果的准确性,对其嵌入Bromley-Zemaitis模型中“Al^(3+)–Cl^(-)”离子对的交互参数进行了修正。随后验证了修正模型的实用性,结果表明它可应用于AlCl_(3)·6H_(2)O在FeCl_(3)、CaCl_(2)及KCl的任意单、混溶液中溶解度的预测。
How to selectively crystallize and separate AlCl_(3)·6H_(2)O from many components is the key to extracting Al from coal gangue,and the thermodynamic equilibrium data of AlCl_(3)·6H_(2)O in the acid leaching system of coal gangue is very important for the control of the crystallization process.The solubilities of AlCl_(3)·6H_(2)O in FeCl_(3),CaCl_(2),KCl and KCl-FeCl_(3)solutions were measured and modeled at temperatures from 25℃to 85℃in this work.The effects of temperature and solution concentration on the solubility of AlCl_(3)·6H_(2)O were studied.The concentration of solution was found to be the main factor which affected the solubility.Solubility of AlCl_(3)·6H_(2)O in all solutions was found to decrease obviously with increasing concentration of solution due to the common ion effect of added Cl^(-).The effect of temperature on the solubility of AlCl_(3)·6H_(2)O in all solutions was slight for the little increment of solubility with increasing temperature.New Bromley–Zemaitis activity coefficient model parameters for the Al^(3+)-Cl^(-)ion pair were obtained by using experimental solubility data.Then the practicability of the modified model was verified,and the results show that it could be used to predict the solubility of AlCl_(3)·6H_(2)O in any single and mixed solution of FeCl_(3),CaCl_(2)and KCl.
作者
程文婷
李杰
徐丽
程芳琴
刘国际
CHENG Wenting;LI Jie;XU Li;CHENG Fangqin;LIU Guoji(State Environmental Protection Key Laboratory on Efficient Resource–utilization Techniques of Coal Waste,Institute of Resources and Environmental Engineering,Shanxi University,Taiyuan 030031,Shanxi,China;School of Chemical Engineering,Zhengzhou University,Zhengzhou 450001,Henan,China)
出处
《化工学报》
EI
CSCD
北大核心
2023年第2期642-652,F0004,共12页
CIESC Journal
基金
国家重点研发计划项目(2022YFC3901305)
国家自然科学基金项目(22208198)。
