There is provided a process for purifying aluminum ions comprising: reacting an aluminum-containing material with an acid so as to obtain a composition comprising aluminum ions; precipitating said aluminum ions in the form of AlCl.sub.3; optionally converting AlCl.sub.3 into Al(OH).sub.3; and heating said AlCl.sub.3 or said Al(OH).sub.3 under conditions effective for converting AlCl.sub.3 or Al(OH).sub.3 into Al.sub.2O.sub.3 and optionally recovering gaseous HCl so-produced. Aluminum ions so purified are thus useful for preparing various types of alumina.

A process of making a silica-alumina composition having improved properties is provided. The process includes (a) mixing an aqueous solution of a silicon compound and an aqueous solution of an aluminum compound and an acid, while maintaining a pH of the mixed solution in a range of 1 to 3, and obtaining an acidified silica-alumina sol; (b) adding an aqueous solution of a base precipitating agent to the acidified silica-alumina sol to a final pH in a range of 5 to 8, and co-precipitating a silica-alumina slurry, wherein the base precipitating agent is selected from ammonium carbonate, ammonium bicarbonate, and any combination thereof; (c) optionally, hydrothermally aging the silica-alumina slurry to form a hydrothermally aged silica-alumina slurry; and (d) recovering a precipitate solid from the silica-alumina slurry or the hydrothermally aged silica-alumina slurry, wherein the precipitate solid comprises the silica-alumina composition.

A process of making a silica-alumina composition having improved properties is provided. The process includes (a) mixing an aqueous solution of a silicon compound and an aqueous solution of an aluminum compound and an acid, while maintaining a pH of the mixed solution in a range of 1 to 3, and obtaining an acidified silica-alumina sol; (b) adding an aqueous solution of a base precipitating agent to the acidified silica-alumina sol to a final pH in a range of 5 to 8, and co-precipitating a silica-alumina slurry, wherein the base precipitating agent is selected from ammonium carbonate, ammonium bicarbonate, and any combination thereof; (c) optionally, hydrothermally aging the silica-alumina slurry to form a hydrothermally aged silica-alumina slurry; and (d) recovering a precipitate solid from the silica-alumina slurry or the hydrothermally aged silica-alumina slurry, wherein the precipitate solid comprises the silica-alumina composition.

The present disclosure provides a preparation method of nano-aluminum oxide (nano-Al.sub.2O.sub.3) with a controllable hydroxyl content, belonging to the technical field of nano-alumina. H.sub.2O.sub.2 dissolved in water dissociates a large number of hydroxyl radicals. In the present disclosure, a resulting H.sub.2O.sub.2 solution is used as a solvent for precipitation; during the precipitation, a soluble aluminum salt and a pore-enlarging agent are reacted to generate a precipitate under alkaline conditions, and the hydroxyl radicals are distributed on a surface of the precipitate. During drying, the hydroxyl radicals are converted into bound water and distributed on a surface and in pores of an aluminum hydroxide precursor; during roasting, the bound water is destroyed to form hydroxyl. The hydroxyl content of the nano-Al.sub.2O.sub.3 can be regulated by controlling a concentration of the H.sub.2O.sub.2 solution, and the nano-Al.sub.2O.sub.3 has the hydroxyl content positively correlated with the concentration of the H.sub.2O.sub.2 solution.

The present disclosure provides a preparation method of nano-aluminum oxide (nano-Al.sub.2O.sub.3) with a controllable hydroxyl content, belonging to the technical field of nano-alumina. H.sub.2O.sub.2 dissolved in water dissociates a large number of hydroxyl radicals. In the present disclosure, a resulting H.sub.2O.sub.2 solution is used as a solvent for precipitation; during the precipitation, a soluble aluminum salt and a pore-enlarging agent are reacted to generate a precipitate under alkaline conditions, and the hydroxyl radicals are distributed on a surface of the precipitate. During drying, the hydroxyl radicals are converted into bound water and distributed on a surface and in pores of an aluminum hydroxide precursor; during roasting, the bound water is destroyed to form hydroxyl. The hydroxyl content of the nano-Al.sub.2O.sub.3 can be regulated by controlling a concentration of the H.sub.2O.sub.2 solution, and the nano-Al.sub.2O.sub.3 has the hydroxyl content positively correlated with the concentration of the H.sub.2O.sub.2 solution.

The present invention relates to a method for recycling iron and aluminum in a nickel-cobalt-manganese solution. The method comprises the following steps: leaching a battery powder and removing copper therefrom to obtain a copper-removed solution, and adjusting the pH value in stages to remove iron and aluminum, so as to obtain a goethite slag and an iron-aluminum slag separately; mixing the iron-aluminum slag with an alkali liquor, and heating and stirring same to obtain an aluminum-containing solution and alkaline slag; and heating and stirring the aluminum-containing solution, introducing carbon dioxide thereto and controlling the pH value to obtain aluminum hydroxide and an aluminum-removed solution.

The present invention relates to a method for recycling iron and aluminum in a nickel-cobalt-manganese solution. The method comprises the following steps: leaching a battery powder and removing copper therefrom to obtain a copper-removed solution, and adjusting the pH value in stages to remove iron and aluminum, so as to obtain a goethite slag and an iron-aluminum slag separately; mixing the iron-aluminum slag with an alkali liquor, and heating and stirring same to obtain an aluminum-containing solution and alkaline slag; and heating and stirring the aluminum-containing solution, introducing carbon dioxide thereto and controlling the pH value to obtain aluminum hydroxide and an aluminum-removed solution.

A blended composition containing uncoated Al.sub.2O.sub.3 flakes having a thickness of ≥500 nm and a D.sub.50-value of 15-30 μm and a D.sub.90-value of 30-45 μm, and/or coated Al.sub.2O.sub.3 flakes having a thickness of ≥500 nm and a D.sub.50-value of 15-30 μm and a D.sub.90-value of 30-45 μm, which have been coated with at least one layer of a metal oxide, mixtures of at least two metal oxides, metal, metal sulphide, titanium suboxide, titanium oxynitride, FeO(OH), metal alloys and/or rare earth compounds, and their use in various formulations.

A blended composition containing uncoated Al.sub.2O.sub.3 flakes having a thickness of ≥500 nm and a D.sub.50-value of 15-30 μm and a D.sub.90-value of 30-45 μm, and/or coated Al.sub.2O.sub.3 flakes having a thickness of ≥500 nm and a D.sub.50-value of 15-30 μm and a D.sub.90-value of 30-45 μm, which have been coated with at least one layer of a metal oxide, mixtures of at least two metal oxides, metal, metal sulphide, titanium suboxide, titanium oxynitride, FeO(OH), metal alloys and/or rare earth compounds, and their use in various formulations.

A process of making a silica-alumina composition having improved properties is provided. The process includes (a) mixing an aqueous solution of a silicon compound and an aqueous solution of an aluminum compound and an acid, while maintaining a pH of the mixed solution in a range of 1 to 3, and obtaining an acidified silica-alumina sol; (b) adding an aqueous solution of a base precipitating agent to the acidified silica-alumina sol to a final pH in a range of 5 to 8, and co-precipitating a silica-alumina slurry, wherein the base precipitating agent is selected from ammonium carbonate, ammonium bicarbonate, and any combination thereof; (c) optionally, hydrothermally aging the silica-alumina slurry to form a hydrothermally aged silica-alumina slurry; and (d) recovering a precipitate solid from the silica-alumina slurry or the hydrothermally aged silica-alumina slurry, wherein the precipitate solid comprises the silica-alumina composition.