The rare earth elements are considered critical metals,due to the risk of supply interruption.The recycling of waste electrical and electronic equipment can be an alternative to supply the rare earth market.Several pr...The rare earth elements are considered critical metals,due to the risk of supply interruption.The recycling of waste electrical and electronic equipment can be an alternative to supply the rare earth market.Several processes have been developed,and by aqueous media is the most prominent,which makes possible the extraction and separation of elements even in low concentration(traces).As an example of thermal processing,the use of thermodynamic simulations might benefit the metal extraction in hydrometallurgical processing.For this reason,the goal of this work is to evaluate the use of FactSage 7.2 software for the leaching of fluorescent lamp powders by sulfuric acid.The effect of concentration and temperature was evaluated.Results comprise that the thermodynamic software wellpredicted the solid phase formed in all residues of leaching experiments-gypsum was predicted by the software and identified in XRD analyses.It demonstrates that FactSage software can be explored for metals extraction in aqueous media,being important for trace-elements extraction.Yttrium extraction reaches up to 95%at 45℃using H_(2)SO_(4)2 mol/L.展开更多
In addition to the news of output restriction by the six rare earth groups,people in the industry were waiting for the confirmation of government stockpiling.Prices of rare earth oxides exhibited quite differently,for...In addition to the news of output restriction by the six rare earth groups,people in the industry were waiting for the confirmation of government stockpiling.Prices of rare earth oxides exhibited quite differently,for they were closely affected by their own applications and the demand from downstream industries.展开更多
<正>August 10~20,2015China rare earth market remained stagnant recently.Demand from NdFeB magnetic industry was weak,which led to the constant price falling of didymium,dysprosium and terbium related products.De...<正>August 10~20,2015China rare earth market remained stagnant recently.Demand from NdFeB magnetic industry was weak,which led to the constant price falling of didymium,dysprosium and terbium related products.Depressed phosphor industry lowered the price of europium and yttrium.The market of lanthanum and cerium was flat.Export market of rare earths remained inactive as well.展开更多
Leaching of rare earths Y, La and Ce by sulphuric acid from fine-grained zirconosilicate ore was investigated using Ta-guchi method of experimental design. An orthogonal array of L8, 27 which denotes 7 factors at 2 le...Leaching of rare earths Y, La and Ce by sulphuric acid from fine-grained zirconosilicate ore was investigated using Ta-guchi method of experimental design. An orthogonal array of L8, 27 which denotes 7 factors at 2 levels was chosen to consider the various factors relevant to the leaching process： baking time, baking temperature, acid dosage, leaching time, leaching temperature, grind size and dilution. Statistical analysis showed that sulphation baking was a significant step for the leaching of rare earths from the whole-of-ore and optimized leaching of rare earths involved the following condition： baking for 3 h at 320 ℃ at 3.2 g acid/g ore acid dosage followed by water leaching at 20 ℃ for 1 h and dilution of 20 mL water/g ore using 300 um grind size. The effect of each leaching factor was also discussed.展开更多
基金the Fundacao de Amparo a Pesquisa do Estado de Sao Paulo and Capes(2018/03483-6 and 2018/11417-3,Sao Paulo Research Foundation)。
文摘The rare earth elements are considered critical metals,due to the risk of supply interruption.The recycling of waste electrical and electronic equipment can be an alternative to supply the rare earth market.Several processes have been developed,and by aqueous media is the most prominent,which makes possible the extraction and separation of elements even in low concentration(traces).As an example of thermal processing,the use of thermodynamic simulations might benefit the metal extraction in hydrometallurgical processing.For this reason,the goal of this work is to evaluate the use of FactSage 7.2 software for the leaching of fluorescent lamp powders by sulfuric acid.The effect of concentration and temperature was evaluated.Results comprise that the thermodynamic software wellpredicted the solid phase formed in all residues of leaching experiments-gypsum was predicted by the software and identified in XRD analyses.It demonstrates that FactSage software can be explored for metals extraction in aqueous media,being important for trace-elements extraction.Yttrium extraction reaches up to 95%at 45℃using H_(2)SO_(4)2 mol/L.
文摘In addition to the news of output restriction by the six rare earth groups,people in the industry were waiting for the confirmation of government stockpiling.Prices of rare earth oxides exhibited quite differently,for they were closely affected by their own applications and the demand from downstream industries.
文摘<正>August 10~20,2015China rare earth market remained stagnant recently.Demand from NdFeB magnetic industry was weak,which led to the constant price falling of didymium,dysprosium and terbium related products.Depressed phosphor industry lowered the price of europium and yttrium.The market of lanthanum and cerium was flat.Export market of rare earths remained inactive as well.
文摘Leaching of rare earths Y, La and Ce by sulphuric acid from fine-grained zirconosilicate ore was investigated using Ta-guchi method of experimental design. An orthogonal array of L8, 27 which denotes 7 factors at 2 levels was chosen to consider the various factors relevant to the leaching process： baking time, baking temperature, acid dosage, leaching time, leaching temperature, grind size and dilution. Statistical analysis showed that sulphation baking was a significant step for the leaching of rare earths from the whole-of-ore and optimized leaching of rare earths involved the following condition： baking for 3 h at 320 ℃ at 3.2 g acid/g ore acid dosage followed by water leaching at 20 ℃ for 1 h and dilution of 20 mL water/g ore using 300 um grind size. The effect of each leaching factor was also discussed.
