Two europium oxide/sulfide silicates, Eu2O（SiO4） （1） and Eu5S（SiO4）3 （2）, have been synthesized using high-temperature solid-state reactions. 1 crystallizes in the monoclinic space group P21/c with a = 9.1459...Two europium oxide/sulfide silicates, Eu2O（SiO4） （1） and Eu5S（SiO4）3 （2）, have been synthesized using high-temperature solid-state reactions. 1 crystallizes in the monoclinic space group P21/c with a = 9.1459（7）, b = 7.1280（5）, c = 6.7655（5） ？ and ？ = 107.611（2）, belonging to the Gd2O（SiO4） structure type; 2 crystallizes in space group P63/m of the hexagonal system with a = 9.786（4） and c = 6.789（3） , belonging to the apatite Ca5Cl（PO4）3 structure type. The structure chemistry of related RE2O（SiO4） and RE5S（SiO4）3 compounds is also discussed. The optical energy gap of 2 is determined to be 2.05 eV.展开更多
The effective and low-temperature extraction of lithium from the pyrometallurgical slag of spent lithium-ion batteries(LIBs)remains a great challenge.Herein,potassium carbonate/sodium carbonate(K_(2)CO_(3)/Na_(2)CO_(3...The effective and low-temperature extraction of lithium from the pyrometallurgical slag of spent lithium-ion batteries(LIBs)remains a great challenge.Herein,potassium carbonate/sodium carbonate(K_(2)CO_(3)/Na_(2)CO_(3)),which could form a eutectic molten salt system at 720℃,was used as a roasting agent to extract lithium from pyrometallurgical slag.Lithium was successfully extracted from the slag by K_(2)CO_(3)/Na_(2)CO_(3) roasting followed by water leaching.Theoretical calculation results indicate that the lengths of Li-O bonds increase after K^(+)/Na^(+)adsorption,resulting in the easy release of Li^(+)from the LiAlSi_(2)O_(6) lattice after roasting with K_(2)CO_(3)/Na_(2)CO_(3).Thermogravimetry-differential scanning calorimetry results indicate that the eutectic phenomenon of K_(2)CO_(3) and Na_(2)CO_(3) could be observed at 720℃ and that the reaction of the slag and eutectic molten salts occurs at temperatures above 720℃.X-ray diffraction results suggest that Li^(+)in the slag is exchanged by K^(+)in K_(2)CO_(3) with the concurrent formation of KAlSiO_(4),while Na_(2)CO_(3) mainly functions as a fluxing agent.The lithium extraction efficiency can reach 93.87%under the optimal conditions of a roasting temperature of 740℃,roasting time of 30 min,leaching temperature of 50℃,leaching time of 40 min,and water/roasted sample mass ratio of 10:1.This work provides a new system for extracting lithium from the pyrometallurgical slag of spent LIBs.展开更多
Effectively extracting lithium at a relatively low temperature from the slag produced by the pyrometallurgical treatment of spent lithium-ion batteries remains a great challenge,which limits the acquirement of lithium...Effectively extracting lithium at a relatively low temperature from the slag produced by the pyrometallurgical treatment of spent lithium-ion batteries remains a great challenge,which limits the acquirement of lithium.Herein,we proposed a eutectic system to roast slag at a lower temperature based on sodium sulfate-sodium chloride(Na_(2)SO_(4)-NaCl)binary eutectic salts.The optimal roasting conditions are as follows:the slag was roasted at 750℃with a(SO_(4)^(2-)+Cl^(-))/Li+molar ratio of 5:1 for 120 min.Followed by aqueous leaching 5 min at room temperature with a water/roasted samples mass ratio of 30:1,it can get 97.07%lithium extraction efficiency.展开更多
The interaction mechanism between sodium arsenate and fayalite-type copper slag at 1200℃was investigated through XRD,XPS,HRTEM,TCLP and other technical means and methods.The results indicated that the proportions of ...The interaction mechanism between sodium arsenate and fayalite-type copper slag at 1200℃was investigated through XRD,XPS,HRTEM,TCLP and other technical means and methods.The results indicated that the proportions of sodium arsenate in the slag and flue gas phases were approximately 30%and 70%,respectively.The addition of sodium arsenate depolymerized the fayalite structure and changed it from a crystalline state to an amorphous state.The fayalite structural changes indicated that the[AsO_(4)]tetrahedron in sodium arsenate combined with the[SiO_(4)]tetrahedron and[FeO_(4)]tetrahedron through bridging oxygen to form a silicate glass structure.The TCLP test results of the samples before and after the high temperature reaction of fayalite and sodium arsenate showed that after high temperature reaction,fayalite could effectively reduce the leaching toxicity of sodium arsenate,reducing the leaching concentration of arsenic from 3025.52 to 12.8 mg/L before and after reaction,respectively.展开更多
基金supported by Yangzhou Engineering Technology Research Center of Petrochemical New Materials(YZM2015086)Yangzhou Science and Technology Bureau(YZ2016269)
文摘Two europium oxide/sulfide silicates, Eu2O（SiO4） （1） and Eu5S（SiO4）3 （2）, have been synthesized using high-temperature solid-state reactions. 1 crystallizes in the monoclinic space group P21/c with a = 9.1459（7）, b = 7.1280（5）, c = 6.7655（5） ？ and ？ = 107.611（2）, belonging to the Gd2O（SiO4） structure type; 2 crystallizes in space group P63/m of the hexagonal system with a = 9.786（4） and c = 6.789（3） , belonging to the apatite Ca5Cl（PO4）3 structure type. The structure chemistry of related RE2O（SiO4） and RE5S（SiO4）3 compounds is also discussed. The optical energy gap of 2 is determined to be 2.05 eV.
基金financially supported by the National Natural Science Foundation of China(No.21276022)。
文摘The effective and low-temperature extraction of lithium from the pyrometallurgical slag of spent lithium-ion batteries(LIBs)remains a great challenge.Herein,potassium carbonate/sodium carbonate(K_(2)CO_(3)/Na_(2)CO_(3)),which could form a eutectic molten salt system at 720℃,was used as a roasting agent to extract lithium from pyrometallurgical slag.Lithium was successfully extracted from the slag by K_(2)CO_(3)/Na_(2)CO_(3) roasting followed by water leaching.Theoretical calculation results indicate that the lengths of Li-O bonds increase after K^(+)/Na^(+)adsorption,resulting in the easy release of Li^(+)from the LiAlSi_(2)O_(6) lattice after roasting with K_(2)CO_(3)/Na_(2)CO_(3).Thermogravimetry-differential scanning calorimetry results indicate that the eutectic phenomenon of K_(2)CO_(3) and Na_(2)CO_(3) could be observed at 720℃ and that the reaction of the slag and eutectic molten salts occurs at temperatures above 720℃.X-ray diffraction results suggest that Li^(+)in the slag is exchanged by K^(+)in K_(2)CO_(3) with the concurrent formation of KAlSiO_(4),while Na_(2)CO_(3) mainly functions as a fluxing agent.The lithium extraction efficiency can reach 93.87%under the optimal conditions of a roasting temperature of 740℃,roasting time of 30 min,leaching temperature of 50℃,leaching time of 40 min,and water/roasted sample mass ratio of 10:1.This work provides a new system for extracting lithium from the pyrometallurgical slag of spent LIBs.
基金supported by the National Natural Science Foun-dation of China(21276022).
文摘Effectively extracting lithium at a relatively low temperature from the slag produced by the pyrometallurgical treatment of spent lithium-ion batteries remains a great challenge,which limits the acquirement of lithium.Herein,we proposed a eutectic system to roast slag at a lower temperature based on sodium sulfate-sodium chloride(Na_(2)SO_(4)-NaCl)binary eutectic salts.The optimal roasting conditions are as follows:the slag was roasted at 750℃with a(SO_(4)^(2-)+Cl^(-))/Li+molar ratio of 5:1 for 120 min.Followed by aqueous leaching 5 min at room temperature with a water/roasted samples mass ratio of 30:1,it can get 97.07%lithium extraction efficiency.
基金the financial supports from the National Natural Science Foundation of China(No.51634010)National Key R&D Program of China(No.2018YFC1900300).
文摘The interaction mechanism between sodium arsenate and fayalite-type copper slag at 1200℃was investigated through XRD,XPS,HRTEM,TCLP and other technical means and methods.The results indicated that the proportions of sodium arsenate in the slag and flue gas phases were approximately 30%and 70%,respectively.The addition of sodium arsenate depolymerized the fayalite structure and changed it from a crystalline state to an amorphous state.The fayalite structural changes indicated that the[AsO_(4)]tetrahedron in sodium arsenate combined with the[SiO_(4)]tetrahedron and[FeO_(4)]tetrahedron through bridging oxygen to form a silicate glass structure.The TCLP test results of the samples before and after the high temperature reaction of fayalite and sodium arsenate showed that after high temperature reaction,fayalite could effectively reduce the leaching toxicity of sodium arsenate,reducing the leaching concentration of arsenic from 3025.52 to 12.8 mg/L before and after reaction,respectively.
