Precipitation transformation of rare earth sulfate into chloride with p-dodecylphenoxy carboxylic acids
来源期刊：JOURNAL OF RARE EARTHS2019年第12期
论文作者：Yanliang Wang Jia Su Xiangguang Guo Jianguo Cui Yan Bai Fujian Li Xiaoqi Sun
文章页码：1326 - 1333
摘 要：Methods for transforming rare earth（RE） sulfate into chloride mainly include extraction process with organophosphonic mono-acids or aliphatic acids and precipitation process with ammonium bicarbonate（NH4 HCO3）.In this paper,alkylphenoxy carboxylic acids（HAs） ofp-dodecylphenoxy acetic acid（HA-Ⅰ）,pdodecylphenoxypropanoic acid（HA-Ⅱ） and p-dodecylphenoxybutyric acid（HA-Ⅲ）,which were liquid at room temperature were synthesized and characterized.The precipitation mechanisms of RE elements with the HAs were investigated and the HA/RE molar ratios of the solid complexes were determined as3:1 by equi-molar series method which accord with the principle of charge balance.Applicability of HAs for the transformation of RE sulfate from concentrated sulfuric acid roasted RE concentrate into chloride via precipitation method was discussed.100% HA-Ⅱ was selected as the liquid organic precipitant without dilution of volatile solvent soracceleration of phase separation by phase-modifiers.The RE sulfate solution can be precipitated by HA-Ⅱ after neutralization with liquid NaOH and stripped with concentrated HCl at room temperature.High concentration of RE chloride of 218.1 g/L with low residue of sulfate radical of 0.536 g/L was obtained.The residual organic precipitant in the raffinate solution was tested to be lower than 8 mg/L at 25℃and the chemical oxygen demand（COD） in wastewater was less than 50 mg/L.
Yanliang Wang1，Jia Su1,2，Xiangguang Guo1，Jianguo Cui3，Yan Bai4，Fujian Li1,5，Xiaoqi Sun1,5
1. CAS Key Laboratory of Design and Assembly of Functional Nanostructures,and Fujian Key Labratory of Nanomaterials,Fujian Institute of Research on the Structure of Matter,Chinese Academy of Sciences2. University of Chinese Academy of Sciences3. Baotou Research Institute of Rare Earths4. State Key Laboratory of Rare Earth Resource Utilization,Changchun Institute of Applied Chemistry, Chinese Academy of Sciences
摘 要：Methods for transforming rare earth（RE） sulfate into chloride mainly include extraction process with organophosphonic mono-acids or aliphatic acids and precipitation process with ammonium bicarbonate（NH4 HCO3）.In this paper,alkylphenoxy carboxylic acids（HAs） ofp-dodecylphenoxy acetic acid（HA-Ⅰ）,pdodecylphenoxypropanoic acid（HA-Ⅱ） and p-dodecylphenoxybutyric acid（HA-Ⅲ）,which were liquid at room temperature were synthesized and characterized.The precipitation mechanisms of RE elements with the HAs were investigated and the HA/RE molar ratios of the solid complexes were determined as3:1 by equi-molar series method which accord with the principle of charge balance.Applicability of HAs for the transformation of RE sulfate from concentrated sulfuric acid roasted RE concentrate into chloride via precipitation method was discussed.100% HA-Ⅱ was selected as the liquid organic precipitant without dilution of volatile solvent soracceleration of phase separation by phase-modifiers.The RE sulfate solution can be precipitated by HA-Ⅱ after neutralization with liquid NaOH and stripped with concentrated HCl at room temperature.High concentration of RE chloride of 218.1 g/L with low residue of sulfate radical of 0.536 g/L was obtained.The residual organic precipitant in the raffinate solution was tested to be lower than 8 mg/L at 25℃and the chemical oxygen demand（COD） in wastewater was less than 50 mg/L.
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