Disclosed herein are system and methods to effectively leach coal ash with hydrochloric acid and separate an insoluble silica product and then selectively precipitate, from the leachate, a number to value-added, strategic, marketable products using a hydroxide reagent. The resulting precipitated products include iron, aluminum, magnesium, calcium, and a mixture of rare earth elements and transition metals. These can be separated as hydroxides or converted to oxides or carbonates. Using hydrochloric acid for leaching and converting the chloride to sodium chloride in the final step results in practically no waste for this process. The silica can be further purified using sodium hydroxide fusion or caustic leach methods and some minor streams from this process are recycled to minimize any waste stream. These systems and methods can be applied to a number of other industrial waste products such as red mud from the aluminum process, slag from steel furnaces, mine tailings, and other metal-bearing waste streams.

A method for producing boehmite under atmospheric pressure may include producing a sodium aluminate solution by dissolving sodium aluminate in water. The method may further include producing an aluminum hydroxide gel by mixing a hydrochloric acid solution with the sodium aluminate solution. The method may further include producing an aluminum chloride solution by mixing a hydrochloric acid solution with the aluminum hydroxide gel. The method may further include producing saturated aluminum chloride solution by heating the aluminum chloride solution. The method may further include producing a boehmite gel by mixing an ammonia solution with the saturated aluminum chloride solution and heating the boehmite gel to produce boehmite.

A method for producing boehmite under atmospheric pressure may include producing a sodium aluminate solution by dissolving sodium aluminate in water. The method may further include producing an aluminum hydroxide gel by mixing a hydrochloric acid solution with the sodium aluminate solution. The method may further include producing an aluminum chloride solution by mixing a hydrochloric acid solution with the aluminum hydroxide gel. The method may further include producing saturated aluminum chloride solution by heating the aluminum chloride solution. The method may further include producing a boehmite gel by mixing an ammonia solution with the saturated aluminum chloride solution and heating the boehmite gel to produce boehmite.

Integrated recycling method and processes including recycling spent catalyst to produce one or more water-soluble metal salts and one or more water-insoluble tail byproducts, and recycling rechargeable batteries to produce one or more battery-grade metals and one or more pure metallic byproducts, wherein the water insoluble tail byproduct is a feedstock in recycling the rechargeable batteries, the impure metallic byproduct is a feedstock in recycling the spent catalyst, or both.

Integrated recycling method and processes including recycling spent catalyst to produce one or more water-soluble metal salts and one or more water-insoluble tail byproducts, and recycling rechargeable batteries to produce one or more battery-grade metals and one or more pure metallic byproducts, wherein the water insoluble tail byproduct is a feedstock in recycling the rechargeable batteries, the impure metallic byproduct is a feedstock in recycling the spent catalyst, or both.

The present invention relates to a porous aluminum hydrate, to a process for preparing same and to the use of same as intermediate in the preparation of an alumina or of a mixed oxide based on aluminum, on cerium and on zirconium. The invention also relates to the alumina obtained from the aluminum hydrate.

The present invention relates to a porous aluminum hydrate, to a process for preparing same and to the use of same as intermediate in the preparation of an alumina or of a mixed oxide based on aluminum, on cerium and on zirconium. The invention also relates to the alumina obtained from the aluminum hydrate.

Provided is a method for inhibiting extractant degradation in the DSX process through the metal extraction control, the method comprising steps of: (a) adding limestone to a copper solvent extraction-raffinate to precipitate iron (Fe) and aluminum (Al) as a slurry, recovering a clarifying liquid; and (b) adding sulfuric acid to the recovered clarifying liquid to adjust the pH thereof.

Provided is a method for inhibiting extractant degradation in the DSX process through the metal extraction control, the method comprising steps of: (a) adding limestone to a copper solvent extraction-raffinate to precipitate iron (Fe) and aluminum (Al) as a slurry, recovering a clarifying liquid; and (b) adding sulfuric acid to the recovered clarifying liquid to adjust the pH thereof.

Process for preparing alumina gel in a single precipitation step consisting of dissolving an aluminium precursor, aluminium chloride, in water, at a temperature of 10 C. to 90 C. such that the pH of the solution is from 0.5 to 5, for a period of 2 to 60 minutes, then adjusting the pH to 7.5 to 9.5 by adding a basic precursor, sodium hydroxide, to the solution obtained to obtain a suspension, at a temperature of 5 C. to 35 C., and for 5 minutes to 5 hours, followed by a filtration step, said process not comprising any washing steps. Also, novel alumina gel having a high dispersibility index, in particular a dispersibility index of more than 80%, a crystallite dimension of 0.5 to 10 nm, a chlorine content of 0.001% to 2% by weight and a sodium content of 0.001% to 2% by weight, the percentages by weight being expressed with respect to the total weight of the alumina gel.