本文選題：稀土浸出液 + 絡(luò)合超濾　； 參考：《江西理工大學(xué)》2015年碩士論文

【摘要】：近年來絡(luò)合-超濾耦合技術(shù)已廣泛應(yīng)用于金屬離子分離濃縮方面的研究。該技術(shù)應(yīng)用于稀土離子濃縮分離具有無沉淀劑加入、絡(luò)合劑可回收再利用、無酸溶過程、無二次污染且富集液中稀土離子濃度高等特點(diǎn)。本課題以稀土浸出液為研究對象,考察了可能影響稀土浸出液絡(luò)合超濾過程的因素,以期為絡(luò)合-超濾技術(shù)在低濃度稀土浸出液分離濃縮中的實(shí)際應(yīng)用提供理論依據(jù)。本文首先以陰離子聚丙烯酰胺(APAM)、聚丙烯酸鈉(PAASS)和聚乙烯亞胺(PEI)為絡(luò)合劑,考察了三種絡(luò)合劑與模擬稀土浸出液的絡(luò)合超濾行為。討論了三種絡(luò)合劑預(yù)處理過程,以及絡(luò)合p H值、裝載比L(絡(luò)合劑與稀土離子質(zhì)量比)和外加Al3+濃度對絡(luò)合超濾行為的影響。結(jié)果如下:(1)經(jīng)過預(yù)處理后三種絡(luò)合劑截留率均達(dá)到100%;(2)對于PAASS和PEI而言,近中性范圍更易于絡(luò)合反應(yīng)的進(jìn)行;(3)PAASS和PEI的最佳裝載比L=0.75;(4)APAM不適宜作為RE3+的絡(luò)合劑;(5)Al3+濃度對稀土浸出液絡(luò)合超濾過程有較大影響,實(shí)際稀土浸出液絡(luò)合超濾前必須除雜。在對模擬稀土浸出液絡(luò)合超濾行為研究的基礎(chǔ),以除雜后的實(shí)際稀土浸出液為研究對象,考察了其與PAASS絡(luò)合超濾過程。實(shí)驗(yàn)確定了中和水解除雜的最佳p H為7.1,并且討論了絡(luò)合p H、裝載比L、操作壓力ΔP和溫度T對絡(luò)合超濾過程的影響,同時(shí)還對濃縮和解絡(luò)實(shí)驗(yàn)進(jìn)行了分析。結(jié)果表明:(1)PAASS與實(shí)際稀土浸出液最佳絡(luò)合條件:p H=6-7,裝載比L=1.0;(2)PAASS與實(shí)際稀土浸出液最佳超濾條件:操作壓力ΔP=0.6Mpa,溫度T=25-30℃;(3)通過絡(luò)合超濾濃縮來提高浸出液中稀土離子濃度是可行,解絡(luò)2小時(shí)后,滲透液中稀土離子濃度Cp,RE為1367mg/L,解離率為71.2%。對PAASS與稀土離子絡(luò)合反應(yīng)分析發(fā)現(xiàn):PAASS可能通過COO-基團(tuán)與RE3+絡(luò)合,且絡(luò)合方式多樣;絡(luò)合反應(yīng)可用一級動(dòng)力學(xué)反應(yīng)來描述,對應(yīng)的反應(yīng)速率常數(shù)k1=0.0357;PAASS與稀土離子絡(luò)合反應(yīng)屬朗格繆爾吸附,由實(shí)驗(yàn)數(shù)據(jù)擬合可得到線性方程相關(guān)性系數(shù)R2=0.997,Langmuir常數(shù)K=0.133。
[Abstract]:In recent years, complex-ultrafiltration coupling technology has been widely used in the separation and concentration of metal ions. The application of this technology to the separation of rare earth ions is characterized by the addition of no precipitator, the recovery and reuse of the complex agent, the absence of acid dissolution process, the absence of secondary pollution and the high concentration of rare earth ions in the enrichment solution. Taking rare earth leachate as the object of study, the factors that may influence the complexation ultrafiltration process of rare earth leachate were investigated in order to provide a theoretical basis for the practical application of complex-ultrafiltration technology in separation and concentration of low concentration rare earth leachate. In this paper, the complexation ultrafiltration behavior of three kinds of complexing agents with simulated rare earth leachate was investigated with anionic polyacrylamide (APAM), sodium polyacrylate (PAASS) and polyethyleneimide (PEI) as the complexing agents. The effects of complex pH value, loading ratio L (mass ratio of complexing agent to rare earth ion) and the concentration of Al3 on the complexation ultrafiltration behavior were discussed. The results were as follows: (1) after pretreatment, the rejection rates of the three kinds of complexing agents reached 100%) for PAASS and PEI, In the near neutral range, it is easier to carry out the complexation reaction. The optimum loading ratio of PEI and PASS is less suitable to be used as the complexing agent of RE3. The concentration of Lian5Al3 has a great influence on the complexation ultrafiltration process of rare earth leachate, and it is necessary to remove the impurities before the complexation ultrafiltration of rare earth leachate. Based on the study of complex ultrafiltration behavior of simulated rare earth leachate, the complex ultrafiltration process with PAASS was investigated by taking the actual rare earth leaching solution after impurity removal as the research object. The optimum pH value of neutralization hydrolysis was determined to be 7.1, and the effects of complexation pH, loading ratio, operating pressure 螖 P and temperature T on the complexation ultrafiltration process were discussed. At the same time, the enrichment and desorption experiments were also analyzed. The results show that the optimal complexation conditions: 1: pHH6 ~ 7, the best ultrafiltration conditions between the loading ratio of L ~ (1.0) O ~ (2 +) PAASS and the actual rare earth leachate are as follows: operating pressure 螖 P _ (0.6) Mpaand temperature T _ (25 ~ 30 鈩，

本文編號：1867719