Effects ofiron and temperature on solubility of light rare earth sulfates in multicomponent system of Fe2（SO4）3-H3PO4-H2SO4 synthetic solution
来源期刊：JOURNAL OF RARE EARTHS2020年第11期
论文作者：Shiliang Chen Longsheng Zhao Meng Wang Zongyu Feng Chao Xia Yang Xu Xiaowei Huang
文章页码：1243 - 1250
摘 要：Numerous light rare earth elements（LREE） minerals containing Fe and P were processed by sulfuric acid roasting method,and the leaching solution mainly comprises LREE sulfate,Fe2（SO4）3,H3PO4,and H2SO4,however,the solubility data of LREE sulfates in this system is few.This work studies the solubility of LREE sulfates in independent LREE sulfate system RE2（SO4）3-Fe2（SO4）3-H3 PO4-H2SO4（RE = La,Ce,Pr or Nd）and mixed LREE sulfates system（La,Ce,Pr,Nd）2（SO4）3-Fe2（SO4）3-H3 PO4-H2SO4 at different temperature（25-65℃） and concentrations of Fe2（SO4）3（Fe2 O3,0-50.13 g/L）,H2SO4（0.5 mol/L）,and H3 PO4（P2 O5,20.34 g/L） based on the industrial operating condition at low liquid and solid ratio 2:1.The solubility of each LREE sulfate in the independent system(La2 O3,12.25-20.88 g/L;CeO2,41.93-62.35 g/L;Pr6 O11,37.34-56.69 g/L;Nd2 O3,26.60-37.63 g/L) is much higher than that of the mixed system(La2 O3,6.95-11.03 g/L;CeO2,10.63-21.51 g/L;Pr6 O11,11.56-20.36 g/L;Nd2 O3,12.36-19.79 g/L) under the same other conditions.The results also indicate that,in the two systems,both Fe and the temperature have negative effects on the solubility of LREE sulfates.That may occur due to the complication reactions between the complexes of RESO4+ and Fe（SO4）2-.However,the influence degree of temperature and iron concentration on the LREE sulfates solubility varies in the two systems and among different LREE species.This research is of theoretical significance for optimizing the conditions of the sulfuric acid process for recovering the LREE from the mixed LREE bearing minerals as well as the single LREE containing secondary rare earth scraps.
Shiliang Chen1,2,3，Longsheng Zhao1,4，Meng Wang1,4，Zongyu Feng1,4，Chao Xia1,4，Yang Xu1,4，Xiaowei Huang1,4
1. National Engineering Research Center for Rare Earth Materials,GRINM Group Co.,Ltd.2. General Research Institute for Nonferrous Metals3. School of Metallurgy,Northeastern University4. Grirem Advanced Materials Co.,Ltd.
摘 要：Numerous light rare earth elements（LREE） minerals containing Fe and P were processed by sulfuric acid roasting method,and the leaching solution mainly comprises LREE sulfate,Fe2（SO4）3,H3PO4,and H2SO4,however,the solubility data of LREE sulfates in this system is few.This work studies the solubility of LREE sulfates in independent LREE sulfate system RE2（SO4）3-Fe2（SO4）3-H3 PO4-H2SO4（RE = La,Ce,Pr or Nd）and mixed LREE sulfates system（La,Ce,Pr,Nd）2（SO4）3-Fe2（SO4）3-H3 PO4-H2SO4 at different temperature（25-65℃） and concentrations of Fe2（SO4）3（Fe2 O3,0-50.13 g/L）,H2SO4（0.5 mol/L）,and H3 PO4（P2 O5,20.34 g/L） based on the industrial operating condition at low liquid and solid ratio 2:1.The solubility of each LREE sulfate in the independent system(La2 O3,12.25-20.88 g/L;CeO2,41.93-62.35 g/L;Pr6 O11,37.34-56.69 g/L;Nd2 O3,26.60-37.63 g/L) is much higher than that of the mixed system(La2 O3,6.95-11.03 g/L;CeO2,10.63-21.51 g/L;Pr6 O11,11.56-20.36 g/L;Nd2 O3,12.36-19.79 g/L) under the same other conditions.The results also indicate that,in the two systems,both Fe and the temperature have negative effects on the solubility of LREE sulfates.That may occur due to the complication reactions between the complexes of RESO4+ and Fe（SO4）2-.However,the influence degree of temperature and iron concentration on the LREE sulfates solubility varies in the two systems and among different LREE species.This research is of theoretical significance for optimizing the conditions of the sulfuric acid process for recovering the LREE from the mixed LREE bearing minerals as well as the single LREE containing secondary rare earth scraps.
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