Mesoporous silica is disclosed possessing a two-dimensional, hexagonal, through-hole structure with a space group p6mm, that is formed using one or more water-soluble oxidized disulfide oil (ODSO) compounds during the synthesis to impart distinct characteristics including an increased percentage of silanol groups.

Room temperature phosphorescent metal-free carbon dots (CDs) embedded in a continuous SiO.sub.2 network (CDs@SiO.sub.2) are made by a method comprising in part grinding biomass and a source of SiO.sub.2 into a powder and soaking the powder with an acidic aqueous solution; washing the powder with deionized water; reacting the powder with an alkaline aqueous solution to form an aqueous solution of CDs from the biomass and Na.sub.2SiO.sub.3 from the source of SiO.sub.2; lowering the pH of the aqueous solution to a value sufficient to cause gelation; and aging the aqueous solution so that the Na.sub.2SiO.sub.3 forms mono-silicic acid (H.sub.4SiO.sub.4), which polymerizes to form a continuous SiO.sub.2 network composed of Si—O tetrahedrons (gel). The method can further comprise calcination of the CDs, wherein the CDs are multi-confined by a continuous SiO.sub.2 network composed of Si—O tetrahedrons. The metal-free CDs are useful in anti-counterfeiting encryption and fingerprint detection systems.

A method for stepwise extraction of silica and hydroxide from silicate substances. The silicate substances are leached by chlorine-containing inorganic acids, and the hydroxides are extracted step by step from the leaching liquor by electrochemical deposition method; The raw material of the powder is put in the reactor, inorganic acids, water-soluble alcohol and water are added as the leaching liquor, heated and reacted under the condition of 0.1 MPa or more, and the acidic multi-ion mixed solution and filter residue are obtained by filtration. The acidic multi-ion mixed solution is heated and boiled, and the silicon-containing volatile components are collected, decomposed and deposited in the collector; The deposited volatile components is dried to obtain high purity silica powder; The filter residue is washed and dried to obtain silica; The hydroxides are extracted from the acidic multi-ion mixed solution by electrochemical deposition method.

The present invention provides an integrated process for carbon dioxide capture, sequestration and utilisation, which comprises: a) providing an aqueous slurry comprising an aqueous liquid and a particulate solid comprising an activated magnesium silicate mineral; b) in a dissolution stage, contacting a CO.sub.2-containing gas stream with the aqueous slurry at a first pressure to dissolve magnesium from the mineral to provide a slurry comprising a magnesium ion enriched carbonated aqueous liquid and a magnesium depleted solid residue; and c) in a precipitation stage, precipitating magnesium carbonate from magnesium ions dissolved in step b) by multiple successive stage-wise reductions in pressure, with each stage being at a lower pressure than the preceding stage;
wherein each successive stage-wise reduction in pressure releases CO.sub.2 which is correspondingly stage-wise compressed and recycled back into the dissolution stage.

Silica particles having a d50 median particle size from 8 to 20 μm, a sphericity factor (S.sub.80) of at least 0.9, a BET surface area from 0.1 to 8 m.sup.2/g, a total mercury intrusion pore volume from 0.35 to 0.8 cc/g, and a loss on ignition from 3 to 7 wt. %, are disclosed, as well as methods for making these silica particles, and dentifrice compositions containing the silica particles.

The present invention describes an integrated process for carbon dioxide capture, sequestration and utilisation, which comprises: a) providing an aqueous slurry comprising an aqueous solution and a particulate solid comprising an activated magnesium silicate mineral; b) in a dissolution stage, contacting a CO.sub.2-containing gas stream with the aqueous slurry to dissolve magnesium from the mineral to provide a magnesium ion enriched aqueous solution and a magnesium depleted solid residue; c) recovering at least a portion of the magnesium depleted solid residue; d) in a separate acid treatment stage, reacting the recovered portion of the magnesium depleted solid residue with a solution comprising a mineral acid or acid salt to further dissolve magnesium and other metals and to provide an acid-treated solid residue; e) recovering the acid-treated solid residue; and f) in a separate precipitation stage, precipitating magnesium carbonate from the magnesium ion enriched aqueous solution.

A method for producing an additive for reclaiming oil from a fluid product stream and a treated silica with controlled hydrophobicity are disclosed. The method includes the steps of providing silica or silicate with a particle size of between 3.0 m to 20 m, the silica or silicates having an agglomerate size of between 10 m to 100 m and being chosen to achieve the desired particle-size range and with a controlled level of hydrophobicity; treating the silica or silicate with a silicone or silane to make it hydrophobic; and controlling the hydrophobicity of the silica or silicate by varying the temperature and treatment time of the silica or silicate, amount of a treating material used to treat the silica or silicate, and the molecular weight of the treating material. The additive improves oil extraction and concentration from a fluid product stream.

A method for stepwise extraction of silica and hydroxide from silicate substances. The silicate substances are leached by chlorine-containing inorganic acids, and the hydroxides are extracted step by step from the leaching liquor by electrochemical deposition method; The raw material of the powder is put in the reactor, inorganic acids, water-soluble alcohol and water are added as the leaching liquor, heated and reacted under the condition of 0.1 MPa or more, and the acidic multi-ion mixed solution and filter residue are obtained by filtration. The acidic multi-ion mixed solution is heated and boiled, and the silicon-containing volatile components are collected, decomposed and deposited in the collector; The deposited volatile components is dried to obtain high purity silica powder; The filter residue is washed and dried to obtain silica; The hydroxides are extracted from the acidic multi-ion mixed solution by electrochemical deposition method.

The invention relates to a novel process for the preparation of a precipitated silica, in which: a silicate is reacted with an acidifying agent, so as to obtain a suspension of precipitated silica, said suspension of precipitated silica is filtered, so as to obtain a filtration cake, said filtration cake is subjected to a liquefaction operation comprising the addition of an aluminum compound, after the liquefaction operation, a drying stage is carried out, characterized in that a polycarboxylic acid chosen from dicarboxylic acids and tricarboxylic acids is added to the filtration cake after the addition of the aluminum compound. It also relates to novel precipitated silicas and to their uses.

It is provided a process of producing amorphous silica from a raw material, such as serpentine, containing silica comprising the steps of mixing the raw material with a hydrochloric acid solution; leaching the raw material obtaining a slurry comprising a liquid fraction and a solid fraction containing silica and minerals; separating the liquid fraction and the solid fraction; removing the minerals from the solid fraction by magnetic separation producing a purified solid silica; drying the purified solid silica; and heating the purified solid silica to remove hydroxyl groups from the silica surface and reducing specific surface area of the resulting amorphous silica.