Disclosed herein are silicon containing polymers and compositions containing the same able to flocculate suspended solids in the Bayer or Sinter process stream.

Methods and compositions for improving performance of flocculants in an industrial production process. Methods include pH triggered cross-linking reaction between a flocculating agent, such as dextran, and a composition comprising a boronic acid-containing polymer. The pH trigger can be provided by a fluid having a pH of 8 or more. The production process can be a Bayer Process and the fluid is caustic liquor or slurry in the fluid circuit of the Bayer, wherein the reaction time is reduced over conventional methods and the cross-linked dextran composition effectuates improved flocculation of the trihydrate particles.

Disclosed herein are silicon containing polymers and compositions containing the same able to flocculate suspended solids in the Bayer or Sinter process stream.

Disclosed herein are silicon containing polymers and compositions containing the same able to flocculate suspended solids in the Bayer or Sinter process stream.

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.

Disclosed herein, is a process for recovering valuable metals and/or their oxides from red mud bauxite residues or similar. The process comprises: calcining a red mud residue having a pH of less than about 10 to provide a calcinated red mud residue; acid leaching the calcinated red mud residue to provide a silica rich solid component and an acid leachate; separating the silica rich solid component and the acid leachate; precipitating an iron rich solid component from the acid leachate; and separating the precipitated iron rich solid component from the acid leachate to provide an aluminium rich liquor.

Disclosed herein are methods and compositions for increasing the alumina content of a bauxite ore prior to alumina extraction by an extractive process, such as the Bayer process. By adding a beneficiation agent to an aqueous ore slurry, then applying a gravitational force to separate, or partition, the slurry into a beneficiary and a gangue, a number of quantifiable benefits are observed. These include increased alumina content and reduced silica content in the beneficiary solids as compared to the starting ore. These benefits are in excess of those observed by pre-extraction gravitational separation of ore slurries without the addition of a beneficiation agent. Beneficiation agents include DADMAC polymers, and combinations of DADMAC polymers with dextrans. The beneficiary is collected and applied to an extractive process, such as the Bayer process.

Bauxite grinding compositions that can significantly reduce the viscosity of bauxite slurry, which allow alumina refinery plants to increase throughput of bauxite grinding or pre-desilication. Described are processes to improve the grinding of a bauxite containing slurry in a Bayer process comprising: adding an effective amount of a bauxite grinding composition to the bauxite containing slurry before or during the grinding step or pre-desilication step, wherein the bauxite grinding composition comprises dextran, maltitol or a co-polymer.

Methods for reducing aluminosilicate containing scale in an alumina recovery process involving treating an alumina recovery process equipment surface with a degradation-resistant scale inhibiting composition having high ionic strength prior to exposure to an alumina recovery process stream.

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.