P507 solvent extraction is the main method to separate and purify the rare earth products.The emulsification may be caused by the impurities in process of extracting rare earths,and these result in huge economic loss ...P507 solvent extraction is the main method to separate and purify the rare earth products.The emulsification may be caused by the impurities in process of extracting rare earths,and these result in huge economic loss and decrease the quality of rare earth products.In recent researches,the extractant was prone to emulsification,and aluminum content of rare earth products also increased,while aluminum concentration of feed was higher.Pointing to this problem,the structural change of saponification P507 extracting aluminum and lanthanum was investigated by infrared spectroscopy,and the results showed that Al ions exchanged with H of P-O-H to become P-O-Al.Because aluminum held the characteristic of hydrophilic after extracted in the form of hydroxyl polymer ions and this provided conditions for the formation of micro emulsion.The organic phase and aqueous phase were investigated by polarizing microscope after aluminum was extracted.The results showed that the organic phase was clear when the extraction capacity of Al was less than 5 g/L.If the extraction capacity of Al exceeded 5 g/L,it formed W/O of ME(micro emulsion),leading to form emulsion of the organic phase.When Al concentration of feed was less than 1 g/L,the aqueous phase would form O/W of ME.If aluminum was extracted by saponification P507 firstly,then the the organic phase loading aluminum extracted rare earth continually,the organic and aqueous phase formed emulsification easily.展开更多
Large amount of high concentration acidic wastewater would be produced in the conversion process of chloride rare earth into oxide rare earth. It was a mixed solution of oxalic acid and hydrochloric acid, so the recyc...Large amount of high concentration acidic wastewater would be produced in the conversion process of chloride rare earth into oxide rare earth. It was a mixed solution of oxalic acid and hydrochloric acid, so the recycling use was very difficult. The method of liquid-liquid extraction was proposed in this paper to achieve wastewater treatment and reclamation. The mechanism of extraction of oxalic acid from the wastewater with the systems of 50% TOB+45% kerosene and 5% 2-ethyl hexanol was investigated. The composition and structure of the extracted species and the establishment of the mathematical model of the oxalic acid extraction were determined by the use of saturation method, equimolar series method. The results showed that extraction of oxalic acid by TOB was a neutral association extraction, oxalic acid existed mainly in a molecular form in the organic phase, and the extraction combination ratio was 2:1. The duality extraction system composed of extractant TOB and TOC had synergistic extraction effect on oxalic acid and chlorhydric acid, and the extraction distribution ratio was improved greatly. The optimum volume fraction of TOB was 0.6-0.8.展开更多
针对稀土萃取过程出口产品的组分含量可以在一定区间范围浮动的要求,提出了一种基于广义预测控制的稀土萃取过程组分含量区间控制方法。首先基于萃取分离过程数据辨识建立组分含量回声状态神经网络(echo state network,ESN)模型;然后针...针对稀土萃取过程出口产品的组分含量可以在一定区间范围浮动的要求,提出了一种基于广义预测控制的稀土萃取过程组分含量区间控制方法。首先基于萃取分离过程数据辨识建立组分含量回声状态神经网络(echo state network,ESN)模型;然后针对稀土萃取过程中不同运行工况,采用改进的广义预测控制算法设计组分含量预测控制器,将系统的输出约束纳入求解控制律的优化问题中,使预测控制针对组分含量输出在不同的区域范围采用不同的控制强度,从而实现区间控制同时保证两端出口产品的纯度,最后基于Ce Pr/Nd(铈镨/钕)萃取过程数据的仿真试验验证了该方法的有效性。展开更多
基金Project supported by the National Natural Science Foundation of China (50974042)Scientific Research Special Foundation of Doctor Subject of Chinese Universities (20090042120015)the Fundamental Research Funds for the Central Universities (N090302007)
文摘P507 solvent extraction is the main method to separate and purify the rare earth products.The emulsification may be caused by the impurities in process of extracting rare earths,and these result in huge economic loss and decrease the quality of rare earth products.In recent researches,the extractant was prone to emulsification,and aluminum content of rare earth products also increased,while aluminum concentration of feed was higher.Pointing to this problem,the structural change of saponification P507 extracting aluminum and lanthanum was investigated by infrared spectroscopy,and the results showed that Al ions exchanged with H of P-O-H to become P-O-Al.Because aluminum held the characteristic of hydrophilic after extracted in the form of hydroxyl polymer ions and this provided conditions for the formation of micro emulsion.The organic phase and aqueous phase were investigated by polarizing microscope after aluminum was extracted.The results showed that the organic phase was clear when the extraction capacity of Al was less than 5 g/L.If the extraction capacity of Al exceeded 5 g/L,it formed W/O of ME(micro emulsion),leading to form emulsion of the organic phase.When Al concentration of feed was less than 1 g/L,the aqueous phase would form O/W of ME.If aluminum was extracted by saponification P507 firstly,then the the organic phase loading aluminum extracted rare earth continually,the organic and aqueous phase formed emulsification easily.
基金Project supported by the Natural Science Foundation of Jiangxi Province (0050009)
文摘Large amount of high concentration acidic wastewater would be produced in the conversion process of chloride rare earth into oxide rare earth. It was a mixed solution of oxalic acid and hydrochloric acid, so the recycling use was very difficult. The method of liquid-liquid extraction was proposed in this paper to achieve wastewater treatment and reclamation. The mechanism of extraction of oxalic acid from the wastewater with the systems of 50% TOB+45% kerosene and 5% 2-ethyl hexanol was investigated. The composition and structure of the extracted species and the establishment of the mathematical model of the oxalic acid extraction were determined by the use of saturation method, equimolar series method. The results showed that extraction of oxalic acid by TOB was a neutral association extraction, oxalic acid existed mainly in a molecular form in the organic phase, and the extraction combination ratio was 2:1. The duality extraction system composed of extractant TOB and TOC had synergistic extraction effect on oxalic acid and chlorhydric acid, and the extraction distribution ratio was improved greatly. The optimum volume fraction of TOB was 0.6-0.8.
文摘针对稀土萃取过程出口产品的组分含量可以在一定区间范围浮动的要求,提出了一种基于广义预测控制的稀土萃取过程组分含量区间控制方法。首先基于萃取分离过程数据辨识建立组分含量回声状态神经网络(echo state network,ESN)模型;然后针对稀土萃取过程中不同运行工况,采用改进的广义预测控制算法设计组分含量预测控制器,将系统的输出约束纳入求解控制律的优化问题中,使预测控制针对组分含量输出在不同的区域范围采用不同的控制强度,从而实现区间控制同时保证两端出口产品的纯度,最后基于Ce Pr/Nd(铈镨/钕)萃取过程数据的仿真试验验证了该方法的有效性。
