中国有色金属学报
中國有色金屬學報
중국유색금속학보
THE CHINESE JOURNAL OF NONFERROUS METALS
2013年
12期
3410-3422
,共13页
司秀芬%张伟光%何利华%梁新星%赵中伟
司秀芬%張偉光%何利華%樑新星%趙中偉
사수분%장위광%하리화%량신성%조중위
Me-Mn-H2O系%LiMn2O4%热力学%卤水提锂
Me-Mn-H2O繫%LiMn2O4%熱力學%滷水提鋰
Me-Mn-H2O계%LiMn2O4%열역학%서수제리
Me-Mn-H2O system%LiMn2O4%thermodynamics%Li extraction from brine
针对高Mg和Li质量比盐湖卤水提锂难的问题,提出利用尖晶石LiMn2O4对盐湖卤水进行选择性提锂,并在热力学计算的基础上绘制了298.15 K时Me(Li,Na,K,Mg)-Mn-H2O体系的φ-pH图,讨论尖晶石LiMn2O4脱Li+后所形成的λ-MnO2对盐湖中Na+、K+、Mg2+与Li+的选择性提取问题。结果表明:当离子浓度为1 mmol/L,体系阴极极化电位降至0.79 V(vs SHE)时,λ-MnO2中Mn4+被还原为Mn3+,同时溶液中Li+由于“记忆效应”而嵌入λ-MnO2晶格生成 LiMn2O4;而极化电位需降至0.61、0.55和0.48 V 时,才分别有 Mg0.5Mn2O4、KMn2O4和NaMn2O4生成,说明所选材料对Li+的选择性优于对Na+、K+和Mg2+的选择性。此外,根据西台吉乃尔盐湖卤水中主要组成阳离子浓度([Li]=30 mmol/L,[Na]=5 mol/L,[K]=0.2 mol/L,[Mg]=0.5 mol/L)绘制Me(Li,Na,K, Mg)-Mn-H2O 系叠加φ-pH 图。热力学研究表明:只需在卤水原始 pH 条件下将体系的阴极极化电位调至0.70 V<φ<0.87 V,λ-MnO2即可实现对Li+与大量Na+、Mg2+、K+的有效分离;将嵌Li+后的LiMn2O4通过调节电位极化至φ>0.87 V,可实现Li+的脱附和富集。
針對高Mg和Li質量比鹽湖滷水提鋰難的問題,提齣利用尖晶石LiMn2O4對鹽湖滷水進行選擇性提鋰,併在熱力學計算的基礎上繪製瞭298.15 K時Me(Li,Na,K,Mg)-Mn-H2O體繫的φ-pH圖,討論尖晶石LiMn2O4脫Li+後所形成的λ-MnO2對鹽湖中Na+、K+、Mg2+與Li+的選擇性提取問題。結果錶明:噹離子濃度為1 mmol/L,體繫陰極極化電位降至0.79 V(vs SHE)時,λ-MnO2中Mn4+被還原為Mn3+,同時溶液中Li+由于“記憶效應”而嵌入λ-MnO2晶格生成 LiMn2O4;而極化電位需降至0.61、0.55和0.48 V 時,纔分彆有 Mg0.5Mn2O4、KMn2O4和NaMn2O4生成,說明所選材料對Li+的選擇性優于對Na+、K+和Mg2+的選擇性。此外,根據西檯吉迺爾鹽湖滷水中主要組成暘離子濃度([Li]=30 mmol/L,[Na]=5 mol/L,[K]=0.2 mol/L,[Mg]=0.5 mol/L)繪製Me(Li,Na,K, Mg)-Mn-H2O 繫疊加φ-pH 圖。熱力學研究錶明:隻需在滷水原始 pH 條件下將體繫的陰極極化電位調至0.70 V<φ<0.87 V,λ-MnO2即可實現對Li+與大量Na+、Mg2+、K+的有效分離;將嵌Li+後的LiMn2O4通過調節電位極化至φ>0.87 V,可實現Li+的脫附和富集。
침대고Mg화Li질량비염호서수제리난적문제,제출이용첨정석LiMn2O4대염호서수진행선택성제리,병재열역학계산적기출상회제료298.15 K시Me(Li,Na,K,Mg)-Mn-H2O체계적φ-pH도,토론첨정석LiMn2O4탈Li+후소형성적λ-MnO2대염호중Na+、K+、Mg2+여Li+적선택성제취문제。결과표명:당리자농도위1 mmol/L,체계음겁겁화전위강지0.79 V(vs SHE)시,λ-MnO2중Mn4+피환원위Mn3+,동시용액중Li+유우“기억효응”이감입λ-MnO2정격생성 LiMn2O4;이겁화전위수강지0.61、0.55화0.48 V 시,재분별유 Mg0.5Mn2O4、KMn2O4화NaMn2O4생성,설명소선재료대Li+적선택성우우대Na+、K+화Mg2+적선택성。차외,근거서태길내이염호서수중주요조성양리자농도([Li]=30 mmol/L,[Na]=5 mol/L,[K]=0.2 mol/L,[Mg]=0.5 mol/L)회제Me(Li,Na,K, Mg)-Mn-H2O 계첩가φ-pH 도。열역학연구표명:지수재서수원시 pH 조건하장체계적음겁겁화전위조지0.70 V<φ<0.87 V,λ-MnO2즉가실현대Li+여대량Na+、Mg2+、K+적유효분리;장감Li+후적LiMn2O4통과조절전위겁화지φ>0.87 V,가실현Li+적탈부화부집。
The spinel LiMn2O4 was chosen for extracting Li+ from brine with high mass ratio of Mg and Li. The corresponding φ-pH diagrams of Me (Li, Na, K, Mg)-Mn-H2O systems at 298.15 K were plotted and analyzed according to thermodynamic calculation when the concentration of Me (Li, Na, K, Mg) was set as 1 mmol/L. The results show that when the redox potential of Li-Mn-H2O system is controlled less than 0.79 V (vs SHE), Mn4+ in λ-MnO2 crystal structure can be reduced to Mn3+, meanwhile, Li+ in solution can be inserted into λ-MnO2 crystal lattice due to memory effect to form LiMn2O4. However, the redox potential for Mg0.5Mn2O4, KMn2O4 and NaMn2O4 is 0.61, 0.55 and 0.48 V, respectively. It indicates that Li+ is prior to be inserted into λ-MnO2 from solution under the same condition compared with Na+, K+and Mg2+. In addition, based on the main cation compositions ([Li]=30 mmo/L, [Na]=5 mol/L, [K]=0.2 mol/L, [Mg]=0.5 mol/L) in West Taijnar Salt Lake brine, the φ-pH diagrams were overlapped. The thermodynamics analysis shows that, in natural brine, it is possible that Li+ can be extracted effectively usingλ-MnO2 when the potential is controlled between 0.70 V and 0.87 V. After that, the formed LiMn2O4 can release Li+ when a voltage 0.87 V is applied. By this means, Li+in brine can be extracted and concentrated.