The present application pertains to methods for making alkali hydroxide, or alkali carbonates, or alkali bicarbonates, or alkaline—earth sulfates. In one embodiment, a material comprising an alkaline earth is converted to an alkaline earth sulfite or bisulfite and reacted with an alkali sulfate to form an alkaline earth sulfate and alkali sulfite or bisulfite. The alkali sulfite or bisulfite is converted into an alkali hydroxide, or an alkali carbonate, or an alkali bicarbonate. In another embodiment, ammonium carbonate or ammonium bicarbonate is reacted with an alkali sulfate, to form ammonium sulfate and an alkali carbonate or alkali bicarbonate. A material comprising an alkaline earth is converted to an alkaline earth sulfite or bisulfite and reacted with the ammonium sulfate to form an alkaline earth sulfate and ammonium sulfite or ammonium bisulfite. The ammonium sulfite or bisulfite is regenerated into ammonia, or ammonium hydroxide, or ammonium carbonate, or ammonium bicarbonate.

The present application pertains to methods for making alkali hydroxide, or alkali carbonates, or alkali bicarbonates, or alkaline—earth sulfates. In one embodiment, a material comprising an alkaline earth is converted to an alkaline earth sulfite or bisulfite and reacted with an alkali sulfate to form an alkaline earth sulfate and alkali sulfite or bisulfite. The alkali sulfite or bisulfite is converted into an alkali hydroxide, or an alkali carbonate, or an alkali bicarbonate. In another embodiment, ammonium carbonate or ammonium bicarbonate is reacted with an alkali sulfate, to form ammonium sulfate and an alkali carbonate or alkali bicarbonate. A material comprising an alkaline earth is converted to an alkaline earth sulfite or bisulfite and reacted with the ammonium sulfate to form an alkaline earth sulfate and ammonium sulfite or ammonium bisulfite. The ammonium sulfite or bisulfite is regenerated into ammonia, or ammonium hydroxide, or ammonium carbonate, or ammonium bicarbonate.

A process for producing a metal oxide powder by flame spray pyrolysis where a) a stream of a solution containing at least one oxidizable or hydrolysable metal compound is atomized to afford an aerosol by means of an atomizer gas, b) this aerosol is brought to reaction in the reaction space of the reactor with a flame obtained by ignition of a mixture of fuel gas and air, c) the reaction stream is cooled and d) the solid product is subsequently removed from the reaction stream, wherein e) the reaction space comprises one or more successive double-walled internals, wherein the wall of the double-walled internal facing the flame-conducting region of the reaction space comprises at least one slot through which a gas or vapour is introduced into the reaction space in which the flame is burning and f) the slot is arranged such that this gas or vapour brings about a rotation of the flame.

The present invention relates to a method for producing lithium hydroxide, and provides a method for producing lithium hydroxide, the method comprising the steps of: preparing lithium carbonate and calcium hydroxide; and reacting the lithium carbonate and the calcium hydroxide in a solvent to obtain an aqueous solution of lithium hydroxide, wherein in the step of reacting the lithium carbonate and the calcium hydroxide in a solvent to obtain an aqueous solution of lithium hydroxide, the concentration of lithium carbonate in the solvent is 110 g/L or less.

The present invention relates to a method for producing lithium hydroxide, and provides a method for producing lithium hydroxide, the method comprising the steps of: preparing lithium carbonate and calcium hydroxide; and reacting the lithium carbonate and the calcium hydroxide in a solvent to obtain an aqueous solution of lithium hydroxide, wherein in the step of reacting the lithium carbonate and the calcium hydroxide in a solvent to obtain an aqueous solution of lithium hydroxide, the concentration of lithium carbonate in the solvent is 110 g/L or less.

A method of making a proppant-gel matrix comprising: a) hydrating a gelling agent to form a hydrated gelling agent; b) adding a basic compound to the hydrated gelling agent to form a basic hydrated gelling agent having a pH in the range of 11.5 to 14.0; c) mixing the basic hydrated gelling agent and a proppant to form a basic hydrated gelling system; and d) adding a crosslinking agent to the basic hydrated gelling system to form the proppant-gel matrix, is disclosed. The proppant-gel matrix can then be used as a fracturing fluid in a hydraulic fracturing process.

A method of making a proppant-gel matrix comprising: a) hydrating a gelling agent to form a hydrated gelling agent; b) adding a basic compound to the hydrated gelling agent to form a basic hydrated gelling agent having a pH in the range of 11.5 to 14.0; c) mixing the basic hydrated gelling agent and a proppant to form a basic hydrated gelling system; and d) adding a crosslinking agent to the basic hydrated gelling system to form the proppant-gel matrix, is disclosed. The proppant-gel matrix can then be used as a fracturing fluid in a hydraulic fracturing process.

A treatment method for reducing carbon dioxide emission of combustion exhaust gas includes: a caustic soda synthesis step; a treatment step of reducing carbon dioxide emission of combustion exhaust gas; and a recycling step. In the caustic soda synthesis step, a natural sodium carbonate aqueous solution (Na.sub.2CO.sub.3) prepared by dissolving natural sodium carbonate ore powder composed of Na.sub.2CO.sub.3 and NaHCO.sub.3 in a caustic soda aqueous solution is used to generate a caustic soda aqueous solution and calcium carbonate precipitate by a causticization reaction with slaked lime, and solid-liquid separation is performed to obtain a synthetic caustic soda aqueous solution. In the treatment step, the synthetic caustic soda aqueous solution and purified combustion exhaust gas are brought into gas-liquid countercurrent contact so that carbon dioxide in the exhaust gas is absorbed by the synthetic caustic soda aqueous solution and immobilized as sodium carbonate.

The invention provides a method of producing a metal oxyhydride, capable of synthesizing the metal oxyhydride under reaction conditions close to atmospheric pressure, and excellent in productivity and cost. The method of producing a metal oxyhydride of the present invention includes reacting an oxide with a metal hydride in a hydrogen atmosphere. A non-oxygen element constituting the oxide comprises only one kind of non-oxygen element. A pressure condition of the reaction is 0.1 to 0.9 MPa, and a temperature of the reaction is 500 to 1000° C.

The invention provides a method of producing a metal oxyhydride, capable of synthesizing the metal oxyhydride under reaction conditions close to atmospheric pressure, and excellent in productivity and cost. The method of producing a metal oxyhydride of the present invention includes reacting an oxide with a metal hydride in a hydrogen atmosphere. A non-oxygen element constituting the oxide comprises only one kind of non-oxygen element. A pressure condition of the reaction is 0.1 to 0.9 MPa, and a temperature of the reaction is 500 to 1000° C.