Excess lithium in alumina is significantly bad for aluminum reduction.In this study,the concentration variation of lithium ion in sodium aluminate solution with addition of synthetic lithium aluminate was investigated...Excess lithium in alumina is significantly bad for aluminum reduction.In this study,the concentration variation of lithium ion in sodium aluminate solution with addition of synthetic lithium aluminate was investigated.Elevating temperature,increasing caustic soda concentration,reducing alumina concentration or raising molar ratioαk improved equilibrium concentration of lithium ion in sodium aluminate solution.Agitation speed had a minimal effect on lithium ion concentration.Over 0.65 g/L lithium ion equilibrium concentration was observed in digestion process,whereas 35 mg/L lithium ion concentration remained in solution after precipitation time of 9 h.Moreover,equilibrium concentration decreased sharply from digestion of boehmite or diaspore to seed precipitation,about 95%lithium was precipitated into red mud(bauxite residue)and aluminum hydroxide.This study provides a valuable perspective in removal or extraction of lithium from sodium aluminate solution in alumina refineries.展开更多
Effect of lithium ion in sodium aluminate solution on precipitation rate,lithium content,morphology,and crystallization of alumina trihydrate(ATH) was investigated. Results showed that increasing lithium ion concentra...Effect of lithium ion in sodium aluminate solution on precipitation rate,lithium content,morphology,and crystallization of alumina trihydrate(ATH) was investigated. Results showed that increasing lithium ion concentration in solution improved the precipitation rate and lithium content in ATH,whereas reduced the mass fraction of lithium precipitation from solution. Lithium ion in solution generated the fine ATH, and thereafter significantly increased the total particle number due to the preferential nucleation.Elevating temperature or reducing lithium ion concentration decreased lithium content in ATH and reduced the fine particle amount.Moreover, lithium ion in the solution changed the morphology of ATH by improving the growth of the(110) and(200) planes of gibbsite.A large amount of fine bar-or flake-shaped ATH attached on the coarse particles also benefited the secondary nucleation and led to the poor strength of alumina.All results will further contribute to improving the quality of alumina.展开更多
基金Project(2015BAB04B01)supported by the National Key Technology R&D Program of ChinaProject(FA2017029)supported by Science and Technology Program of Chongzuo,ChinaProject(CSUZC201811)supported by the Open-End Fund for the Valuable and Precision Instruments of Central South University,China
文摘Excess lithium in alumina is significantly bad for aluminum reduction.In this study,the concentration variation of lithium ion in sodium aluminate solution with addition of synthetic lithium aluminate was investigated.Elevating temperature,increasing caustic soda concentration,reducing alumina concentration or raising molar ratioαk improved equilibrium concentration of lithium ion in sodium aluminate solution.Agitation speed had a minimal effect on lithium ion concentration.Over 0.65 g/L lithium ion equilibrium concentration was observed in digestion process,whereas 35 mg/L lithium ion concentration remained in solution after precipitation time of 9 h.Moreover,equilibrium concentration decreased sharply from digestion of boehmite or diaspore to seed precipitation,about 95%lithium was precipitated into red mud(bauxite residue)and aluminum hydroxide.This study provides a valuable perspective in removal or extraction of lithium from sodium aluminate solution in alumina refineries.
基金Project(2015BAB04B01)supported by the National Key Technology Research&Development Program of ChinaProject(CSUZC201811)supported by the Open-End Fund for the Valuable and Precision Instruments of Central South University,China
文摘Effect of lithium ion in sodium aluminate solution on precipitation rate,lithium content,morphology,and crystallization of alumina trihydrate(ATH) was investigated. Results showed that increasing lithium ion concentration in solution improved the precipitation rate and lithium content in ATH,whereas reduced the mass fraction of lithium precipitation from solution. Lithium ion in solution generated the fine ATH, and thereafter significantly increased the total particle number due to the preferential nucleation.Elevating temperature or reducing lithium ion concentration decreased lithium content in ATH and reduced the fine particle amount.Moreover, lithium ion in the solution changed the morphology of ATH by improving the growth of the(110) and(200) planes of gibbsite.A large amount of fine bar-or flake-shaped ATH attached on the coarse particles also benefited the secondary nucleation and led to the poor strength of alumina.All results will further contribute to improving the quality of alumina.
