A variety of systems, methods and compositions are disclosed, including, in one method for recycling a spent alkaline battery comprising: dissolving insoluble metal ions in aqueous solution thereby producing pregnant leach solution; extracting zinc sulfate from aqueous solution thereby producing zinc sulfate product and raffinate solution comprising manganese sulfate and potassium sulfate; separating manganese hydroxide from raffinate solution thereby producing manganese sulfate product and aqueous potassium sulfate solution; crystallizing aqueous potassium sulfate solution to produce solid potassium sulfate product. A system for recycling spent alkaline battery comprising: first liquid-solid extraction unit capable of dissolving insoluble metal ions in aqueous solution thereby producing pregnant leach solution; liquid-liquid extraction unit capable of extracting zinc from pregnant leach solution; second liquid-solid extraction unit capable of precipitating manganese hydroxide from raffinate produced by liquid-liquid extraction unit; and third liquid-solid extraction unit capable of crystallizing aqueous potassium sulfate solution produced by second liquid-solid extraction unit.

A variety of systems, methods and compositions are disclosed, including, in one method for recycling a spent alkaline battery comprising: dissolving insoluble metal ions in aqueous solution thereby producing pregnant leach solution; extracting zinc sulfate from aqueous solution thereby producing zinc sulfate product and raffinate solution comprising manganese sulfate and potassium sulfate; separating manganese hydroxide from raffinate solution thereby producing manganese sulfate product and aqueous potassium sulfate solution; crystallizing aqueous potassium sulfate solution to produce solid potassium sulfate product. A system for recycling spent alkaline battery comprising: first liquid-solid extraction unit capable of dissolving insoluble metal ions in aqueous solution thereby producing pregnant leach solution; liquid-liquid extraction unit capable of extracting zinc from pregnant leach solution; second liquid-solid extraction unit capable of precipitating manganese hydroxide from raffinate produced by liquid-liquid extraction unit; and third liquid-solid extraction unit capable of crystallizing aqueous potassium sulfate solution produced by second liquid-solid extraction unit.

A process for generating a metal sulfate that involves crystallizing a metal sulfate from an aqueous solution to form a crystallized metal sulfate in a mother liquor with uncrystallized metal sulfate remaining in the mother liquor; separating the crystallized metal sulfate from the mother liquor; basifying a portion of the mother liquor to convert the uncrystallized metal sulfate to a basic metal salt; and using the basic metal salt upstream of crystallizing the metal sulfate. So crystallized, the generated metal sulfate may be battery-grade or electroplating-grade.

Herein disclosed are compositions for passive NOx adsorption and oxidation that include at least a manganese-based oxide and one or more promoter materials and methods for making and using said compositions. The promotor materials may include a rare earth, transition, or main group metal. The compositions may be used in NOx emission control system and adsorbs NOx compounds at low temperatures and then release NOx at higher temperatures, where the NOx can be oxidized, without the hybridized MnOX composition breaking down. The compositions are capable of maintaining a sufficiently large surface area at high temperatures found in the emissions gas streams of internal combustion engines necessary for the complete elimination of NOx.

Herein disclosed are compositions for passive NOx adsorption and oxidation that include at least a manganese-based oxide and one or more promoter materials and methods for making and using said compositions. The promotor materials may include a rare earth, transition, or main group metal. The compositions may be used in NOx emission control system and adsorbs NOx compounds at low temperatures and then release NOx at higher temperatures, where the NOx can be oxidized, without the hybridized MnOX composition breaking down. The compositions are capable of maintaining a sufficiently large surface area at high temperatures found in the emissions gas streams of internal combustion engines necessary for the complete elimination of NOx.

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 invention relates to a method for treating a residue obtained from the chloride process, wherein the residue comprises the components titanium dioxide, coke, an inert metal oxide, and an iron-containing component. Further, the invention refers to the use of this method to separate the components contained in said residue, and to the use of the separated components in the chloride process for obtaining titanium dioxide.

The invention relates to a method for treating a residue obtained from the chloride process, wherein the residue comprises the components titanium dioxide, coke, an inert metal oxide, and an iron-containing component. Further, the invention refers to the use of this method to separate the components contained in said residue, and to the use of the separated components in the chloride process for obtaining titanium dioxide.

Process for precipitating a carbonate or (oxy)hydroxide comprising nickel from an aqueous solution of a nickel salt wherein such process is carried out in a vessel comprising (A) a vessel body, (B) one or more elements that control the hydraulic flow of the slurry formed during the precipitation and that induce a loop-type circulation flow, and (C) a stirrer whose stirrer element is in the vessel but located separately from the element(s) (B).