Abstract:
Disclosed is a method of recovering rare earth, aluminum and silicon from rare earth-containing aluminum-silicon scrap. The method comprises: S1, acid-leaching the rare earth-containing aluminum-silicon scrap with an inorganic acid aqueous solution to obtain a silicon-rich slag and acid leached solution containing rare earth and aluminum element; S2, adding an alkaline substance into the acid leached solution containing the rare earth and aluminum element and controlling a PH value of the acid leaching solution between 3.5 to 5.2, performing a solid-liquid separation to obtain a aluminum hydroxide-containing precipitate and a rare earth-containing solution filter; S3, reacting the aluminum hydroxide containing precipitate with sodium hydroxidee to obtain sodium metaaluminate solution and aluminum-silicon slag, and preparing a rare earth compound product with the rare earth-containing filtrate. The method dissolves an the aluminum and the rare earth with the acid and then via step wise alkaline conversion, convert aluminum icons to an aluminum hydroxide precipitate separated from rare earth ions, and then adds excessive amounts of sodium hydroxide to convert the aluminum hydroxide to a sodium metaaluminate solution, thereby realizing high-efficiency recovery of both rare earth and aluminum while significantly reducing the consumption of the sodium hydroxide and thus recovery cost.
Abstract:
The present invention provides a cerium oxide based composite polishing powder and a preparation method thereof. The polishing powder contains the element magnesium in an amount of 0.005 wt %-5 wt % to magnesium oxide meter. The preparation method includes: (1) uniformly mixing a salt solution containing cerium serving as the main component of the polishing powder; (2) uniformly mixing a precipitating agent of an aqueous magnesium bicarbonate solution with the mixed solution prepared in step (1) to obtain a slurry; (3) aging the slurry prepared in step (2) for 0-48 h while the temperature of the slurry is kept at 30-90 degrees centigrade, and filtering the aged slurry to obtain the precursor powder of the polishing powder; (4) calcinating the precursor powder at 600-1000 degrees centigrade, then dispersing and separating the calcinated precursor powder to obtain the polishing powder. The present invention improves the polishing performance and the suspension performance of polishing powder.
Abstract:
Disclosed is a method of recovering rare earth, aluminum and silicon from rare earth-containing aluminum-silicon scrap. The method comprises: S1, acid-leaching the rare earth-containing aluminum-silicon scrap with an inorganic acid aqueous solution to obtain a silicon-rich slag and acid leached solution containing rare earth and aluminum element; S2, adding an alkaline substance into the acid leached solution containing the rare earth and aluminum element and controlling a PH value of the acid leaching solution between 3.5 to 5.2, performing a solid-liquid separation to obtain a aluminum hydroxide-containing precipitate and a rare earth-containing solution filter; S3, reacting the aluminum hydroxide containing precipitate with sodium hydroxide to obtain sodium metaaluminate solution and aluminum-silicon slag, and preparing a rare earth compound product with the rare earth-containing filtrate. The method dissolves an the aluminum and the rare earth with the acid and then via step wise alkaline conversion, convert aluminum icons to an aluminum hydroxide precipitate separated from rare earth ions, and then adds excessive amounts of sodium hydroxide to convert the aluminum hydroxide to a sodium metaaluminate solution, thereby realizing high-efficiency recovery of both rare earth and aluminum while significantly reducing the consumption of the sodium hydroxide and thus recovery cost.
Abstract:
A method for comprehensively recovering rare earth elements and fluorine element in a bastnaesite treatment process. The method comprises: oxidation roasting a bastnaesite, and leaching a roasted mixture using a hydrochloric acid, adding a roasting promoter to the bastnaesite during the roasting process; and/or during the leaching process using the hydrochloric acid, adding a catalytic leaching promoter into the mixture, obtaining a rare earth chloride solution containing little cerium element and a cerium-rich residue containing the fluorine element; and separating and recovering rare earth fluorides from the cerium-rich residue.
Abstract:
A method for comprehensively recovering rare earth elements and fluorine element in a bastnaesite treatment process. The method comprises: oxidation roasting a bastnaesite, and leaching a roasted mixture using a hydrochloric acid, adding a roasting promoter to the bastnaesite during the roasting process; and/or during the leaching process using the hydrochloric acid, adding a catalytic leaching promoter into the mixture, obtaining a rare earth chloride solution containing little cerium element and a cerium-rich residue containing the fluorine element; and separating and recovering rare earth fluorides from the cerium-rich residue.
Abstract:
The present invention provides a cerium oxide based composite polishing powder and a preparation method thereof. The polishing powder contains the element magnesium in an amount of 0.005 wt %-5 wt % to magnesium oxide meter. The preparation method includes: (1) uniformly mixing a salt solution containing cerium serving as the main component of the polishing powder; (2) uniformly mixing a precipitating agent of an aqueous magnesium bicarbonate solution with the mixed solution prepared in step (1) to obtain a slurry; (3) aging the slurry prepared in step (2) for 0-48 h while the temperature of the slurry is kept at 30-90 degrees centigrade, and filtering the aged slurry to obtain the precursor powder of the polishing powder; (4) calcinating the precursor powder at 600-1000 degrees centigrade, then dispersing and separating the calcinated precursor powder to obtain the polishing powder. The present invention improves the polishing performance and the suspension performance of polishing powder.