Provided are a flame retardant which is good in dispersibility in an organic polymeric material, and does not lower, even after mixed with an organic polymeric material, material properties thereof; a flame retardant composition; and a shaped body. The flame retardant of the present invention includes magnesium hydroxide particles subjected to a surface treatment, the particles satisfying the following (A) to (D): (A) an average particle size is 2 m or less according to a laser diffraction method; (B) a BET specific surface area is 3 to 15 m.sup.2/g; (C) a degree of mono-dispersion is 50% or more, the degree of mono-dispersion being represented by the following equation: Degree of mono-dispersion (%)=(average primary particle size [m] of particles according to SEM observation/average particle size [m] of particles according to laser diffraction method)100; and, (D) just after 1 mL of a 0.1 M solution of nitric acid is dropwise added at a dropping rate of 0.1 mL/minute to a suspension obtained by adding 1.0 g of the flame retardant to 100 mL of an aqueous mixed solution containing 0.1% by weight of each of a wetting agent and an electrolyte, pH of the suspension is 9.0 or less according to a potentiometric titration.

Provided are a flame retardant which is good in dispersibility in an organic polymeric material, and does not lower, even after mixed with an organic polymeric material, material properties thereof; a flame retardant composition; and a shaped body. The flame retardant of the present invention includes magnesium hydroxide particles subjected to a surface treatment, the particles satisfying the following (A) to (D): (A) an average particle size is 2 m or less according to a laser diffraction method; (B) a BET specific surface area is 3 to 15 m.sup.2/g; (C) a degree of mono-dispersion is 50% or more, the degree of mono-dispersion being represented by the following equation: Degree of mono-dispersion (%)=(average primary particle size [m] of particles according to SEM observation/average particle size [m] of particles according to laser diffraction method)100; and, (D) just after 1 mL of a 0.1 M solution of nitric acid is dropwise added at a dropping rate of 0.1 mL/minute to a suspension obtained by adding 1.0 g of the flame retardant to 100 mL of an aqueous mixed solution containing 0.1% by weight of each of a wetting agent and an electrolyte, pH of the suspension is 9.0 or less according to a potentiometric titration.

Processes for regenerating alkali process streams are disclosed herein, including streams containing sodium hydroxide, magnesium hydroxide, and combinations thereof. Systems for regenerating alkali process streams are disclosed herein, including streams containing sodium hydroxide, magnesium hydroxide, and combinations thereof.

Processes for regenerating alkali process streams are disclosed herein, including streams containing sodium hydroxide, magnesium hydroxide, and combinations thereof. Systems for regenerating alkali process streams are disclosed herein, including streams containing sodium hydroxide, magnesium hydroxide, and combinations thereof.

A method for activation of magnesium silicate minerals by conversion to magnesium hydroxide for sequestration of carbon dioxide (CO.sub.2) is provided. The method includes heating a dry solid-solid mixture of an alkaline earth Silicate-based material with an alkali metal compound at a temperature below 300 C to form a solid product predominantly comprising a mixture of magnesium hydroxide and alkali metal silicate, wherein the Silicate-based material comprises a naturally occurring Olivine, Serpentine mineral and alkali metal silicate. The method includes a subsequent dissolution of the solid product in aqueous solution to form an alkaline aqueous liquid slurry, comprising solid and aqueous phase products and the reaction of the solid phase thus formed with Carbon Dioxide (CO.sub.2), producing a metal Carbonate. The method provides a process that has shown significant cost and energy efficiencies for producing magnesium hydroxide and CO.sub.2 sequestration via mineral carbonation.

A method for activation of magnesium silicate minerals by conversion to magnesium hydroxide for sequestration of carbon dioxide (CO.sub.2) is provided. The method includes heating a dry solid-solid mixture of an alkaline earth Silicate-based material with an alkali metal compound at a temperature below 300 C to form a solid product predominantly comprising a mixture of magnesium hydroxide and alkali metal silicate, wherein the Silicate-based material comprises a naturally occurring Olivine, Serpentine mineral and alkali metal silicate. The method includes a subsequent dissolution of the solid product in aqueous solution to form an alkaline aqueous liquid slurry, comprising solid and aqueous phase products and the reaction of the solid phase thus formed with Carbon Dioxide (CO.sub.2), producing a metal Carbonate. The method provides a process that has shown significant cost and energy efficiencies for producing magnesium hydroxide and CO.sub.2 sequestration via mineral carbonation.

Methods and composition are provided for deriving cement and/or supplementary cementitious materials, such as pozzolans, from one or more non-limestone materials, such as one or more non-limestone rocks and/or minerals. The non-limestone materials, e.g., non-limestone rocks and/or minerals, are processed in a manner that a desired product, e.g., cement and/or supplementary cementitious material, is produced.

The present invention discloses a method for producing lithium carbonate from a low-lithium brine by separating magnesium and enriching lithium. A salt-lake brine is used as a raw material and is converted into halide salts through dehydration by evaporation and separation by crystallization; the halide salts are directly extracted using trialkyl phosphate or a mixture of trialkyl phosphate and monohydric alcohol, and an organic extraction phase as well as remaining halide salts are obtained after solid-liquid separation; reverse extraction is performed on the organic extraction phase to obtain a lithium-rich solution with a low magnesium-to-lithium ratio, and lithium carbonate is obtained after concentration and removal of magnesium by alkalization. The used solid-liquid extraction method is simple with no co-extraction agent used, and a solute distribution driving force is strong, unaffected by phase equilibrium of the brine extraction agent. The mass ratio of magnesium-to-lithium significantly decreases in the extraction phase.

An object of the present invention is to provide magnesium oxide particles that have a high heat conductivity and excellent properties as heat-dissipating filler, and can prevent problems such as soft errors in the memory. The magnesium oxide particles have a BET specific surface area of 0.1 to 17 m.sup.2/g, and an dose of 0.005 c/cm.sup.2.Math.Hr or lower, the particles exhibiting a relation between an X-ray diffraction peak intensity y (cps) at a Bragg angle (2) of 42.80 to 43.00 and the BET specific surface area x (m.sup.2/g) as represented by the following inequality (1):
y960x+33000(1).

An object of the present invention is to provide magnesium oxide particles that have a high heat conductivity and excellent properties as heat-dissipating filler, and can prevent problems such as soft errors in the memory. The magnesium oxide particles have a BET specific surface area of 0.1 to 17 m.sup.2/g, and an dose of 0.005 c/cm.sup.2.Math.Hr or lower, the particles exhibiting a relation between an X-ray diffraction peak intensity y (cps) at a Bragg angle (2) of 42.80 to 43.00 and the BET specific surface area x (m.sup.2/g) as represented by the following inequality (1):
y960x+33000(1).