通过纯矿物浮选、Zeta电位测试、溶液化学计算、红外光谱分析及XPS测试,研究以羟肟酸为捕收剂浮选稀土时Ce^(3+)离子对萤石的活化作用机理。结果表明:矿浆中Ce^(3+)离子浓度低于羟肟酸时在p H 6~12对萤石都具有活化作用,其活化机理为Ce^...通过纯矿物浮选、Zeta电位测试、溶液化学计算、红外光谱分析及XPS测试,研究以羟肟酸为捕收剂浮选稀土时Ce^(3+)离子对萤石的活化作用机理。结果表明:矿浆中Ce^(3+)离子浓度低于羟肟酸时在p H 6~12对萤石都具有活化作用,其活化机理为Ce^(3+)离子吸附提高萤石表面的正电性,增强萤石表面与阴离子羟肟酸捕收剂的静电吸附作用,且在萤石表面形成F-Ce(OH)_2/Ce(OH)^+活性位点。红外光谱和XPS测试表明,无Ce^(3+)离子活化时,辛基羟肟酸在萤石表面主要生成不稳定的四元环络合物—C—O—Ca—N—,羟肟酸与Ca^(2+)离子结合能小,直接在萤石表面的吸附作用弱;被Ce^(3+)离子活化后,辛基羟肟酸与萤石表面Ce^(3+)离子反应生成稳定的五元环络合物—C=O—Ce—O—N—,羟肟酸与Ce^(3+)离子结合能大,加强羟肟酸在萤石表面的吸附作用,从而使萤石被活化。展开更多
The nanocrystalline and amorphous Mg2Ni-type alloys with a chemical composition of （Mg24Ni10Cu2）100-xNdx （x=0, 5, 10, 15, 20） were fabricated by melt spinning technology. The effects of spinning rate on the struct...The nanocrystalline and amorphous Mg2Ni-type alloys with a chemical composition of （Mg24Ni10Cu2）100-xNdx （x=0, 5, 10, 15, 20） were fabricated by melt spinning technology. The effects of spinning rate on the structure and electrochemical hydrogen storage performance of the alloys were investigated. The as-spun Nd-free alloy displays an entire nanocrystalline structure, whereas the as-spun Nd-added alloys hold a nanocrystalline and amorphous structure, suggesting that the addition of Nd facilitates the glass forming of the Mg2Ni-type alloys. Increasing the spinning rate from 0 to 40 m/s gives rise to the discharge capacity growing from 42.5 to 100.6 mA·h/g for the x=0 alloy and from 86.4 to 452.8 mA·h/g for the x=10 alloy. And the cycle stability （S20） rises from 40.2%to 41.1%for the x=0 alloy and from 53.2%to 89.7%for the x=10 alloy, respectively.展开更多
文摘通过纯矿物浮选、Zeta电位测试、溶液化学计算、红外光谱分析及XPS测试,研究以羟肟酸为捕收剂浮选稀土时Ce^(3+)离子对萤石的活化作用机理。结果表明:矿浆中Ce^(3+)离子浓度低于羟肟酸时在p H 6~12对萤石都具有活化作用,其活化机理为Ce^(3+)离子吸附提高萤石表面的正电性,增强萤石表面与阴离子羟肟酸捕收剂的静电吸附作用,且在萤石表面形成F-Ce(OH)_2/Ce(OH)^+活性位点。红外光谱和XPS测试表明,无Ce^(3+)离子活化时,辛基羟肟酸在萤石表面主要生成不稳定的四元环络合物—C—O—Ca—N—,羟肟酸与Ca^(2+)离子结合能小,直接在萤石表面的吸附作用弱;被Ce^(3+)离子活化后,辛基羟肟酸与萤石表面Ce^(3+)离子反应生成稳定的五元环络合物—C=O—Ce—O—N—,羟肟酸与Ce^(3+)离子结合能大,加强羟肟酸在萤石表面的吸附作用,从而使萤石被活化。
基金Projects (51161015,51371094) supported by the National Natural Science Foundation of ChinaProject (2011ZD10) supported by the Natural Science Foundation of Inner Mongolia,China
文摘The nanocrystalline and amorphous Mg2Ni-type alloys with a chemical composition of （Mg24Ni10Cu2）100-xNdx （x=0, 5, 10, 15, 20） were fabricated by melt spinning technology. The effects of spinning rate on the structure and electrochemical hydrogen storage performance of the alloys were investigated. The as-spun Nd-free alloy displays an entire nanocrystalline structure, whereas the as-spun Nd-added alloys hold a nanocrystalline and amorphous structure, suggesting that the addition of Nd facilitates the glass forming of the Mg2Ni-type alloys. Increasing the spinning rate from 0 to 40 m/s gives rise to the discharge capacity growing from 42.5 to 100.6 mA·h/g for the x=0 alloy and from 86.4 to 452.8 mA·h/g for the x=10 alloy. And the cycle stability （S20） rises from 40.2%to 41.1%for the x=0 alloy and from 53.2%to 89.7%for the x=10 alloy, respectively.
