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.

The invention provides a method of inhibiting the accumulation of DSP scale in the liquor circuit of Bayer process equipment. The method includes adding one or more particular silane based small molecules to the liquor fluid circuit. These scale inhibitors reduce DSP scale formation and thereby increase fluid throughput, increase the amount of time Bayer process equipment can be operational and reduce the need for expensive and dangerous acid washes of Bayer process equipment. As a result, the invention provides a significant reduction in the total cost of operating a Bayer process.

A method for recovering alkali and aluminum during treatment of Bayer red mud using a calcification-carbonation method, including steps of mixing the Bayer red mud with calcium aluminate or with calcium aluminate and lime, performing calcification dealkalization conversion in a high-concentration alkaline liquor, and carbonizing the calcified residues produced during dealkalization to obtain carbonized residues; and then performing low-temperature aluminum dissolution, aluminum precipitation and the like to obtain calcium aluminate products, which is returned to the calcification dealkalization conversion of the red mud for recycling. Part of an alkali-containing and aluminum-containing liquid phase after calcification dealkalization conversion can be used as supplementary alkali in the Bayer production course for recycling. The method is energy-saving and environmentally-friendly, and allows recovering alkali and aluminum from the red mud and harmless treatment of the Bayer red mud.

A method for recovering alkali and aluminum during treatment of Bayer red mud using a calcification-carbonation method, including steps of mixing the Bayer red mud with calcium aluminate or with calcium aluminate and lime, performing calcification dealkalization conversion in a high-concentration alkaline liquor, and carbonizing the calcified residues produced during dealkalization to obtain carbonized residues; and then performing low-temperature aluminum dissolution, aluminum precipitation and the like to obtain calcium aluminate products, which is returned to the calcification dealkalization conversion of the red mud for recycling. Part of an alkali-containing and aluminum-containing liquid phase after calcification dealkalization conversion can be used as supplementary alkali in the Bayer production course for recycling. The method is energy-saving and environmentally-friendly, and allows recovering alkali and aluminum from the red mud and harmless treatment of the Bayer red mud.

A method of purifying a spinel powder includes contacting a spinel powder with an acid solution to form an acid-washed spinel composition and contacting the acid-washed spinel composition with a basic solution to form a purified composition. The purified powder is suited to formation of low-absorption shaped bodies, such as windows for high intensity laser devices.

A Bayer process includes contacting bauxite and calcium fluoride with sodium hydroxide and forming a slurry, with the calcium fluoride may provide at least 1 wt. % of the calcium added to the process, and precipitating alumina from the slurry.

A Bayer process includes contacting bauxite and calcium fluoride with sodium hydroxide and forming a slurry, with the calcium fluoride may provide at least 1 wt. % of the calcium added to the process, and precipitating alumina from the slurry.

The present disclosure relates to a lithium compound for recovering valuable metals and a method of recovering the same, and a method of recovering a lithium compound for recovering valuable metals includes: preparing a battery; freezing and forcibly discharging the battery; shredding the battery into a battery shredded material; and heating the battery shredded material, wherein the heating of the battery is performed in a temperature range of 1,100 to 1,400 C., a degree of vacuum (Log P [atm]) in the heating of the battery is in a range of 4 to 0, a lithium compound recovered through the heating of the battery contains impurities, and the impurities include, by wt %, 1.8 wt % or less (excluding 0 wt %) of Na, 0.06 wt % or less (excluding 0 wt %) of K, 0.62 wt % or less (excluding 0 wt %) of Ca, and 0.47 wt % or less (excluding 0 wt %) of Mg.

The present disclosure relates to a lithium compound for recovering valuable metals and a method of recovering the same, and a method of recovering a lithium compound for recovering valuable metals includes: preparing a battery; freezing and forcibly discharging the battery; shredding the battery into a battery shredded material; and heating the battery shredded material, wherein the heating of the battery is performed in a temperature range of 1,100 to 1,400 C., a degree of vacuum (Log P [atm]) in the heating of the battery is in a range of 4 to 0, a lithium compound recovered through the heating of the battery contains impurities, and the impurities include, by wt %, 1.8 wt % or less (excluding 0 wt %) of Na, 0.06 wt % or less (excluding 0 wt %) of K, 0.62 wt % or less (excluding 0 wt %) of Ca, and 0.47 wt % or less (excluding 0 wt %) of Mg.

The present invention relates to a waste battery treatment method which includes preparing a waste battery including a waste positive electrode which includes an aluminum current collector and a positive electrode active material layer formed on at least one surface of the aluminum current collector, heat treating the waste battery at a temperature of 650 C. or higher in an air atmosphere or oxidizing atmosphere to convert the aluminum current collector into aluminum oxide, and recovering aluminum oxide powder and positive electrode active material powder from the heat-treated waste battery.