Process for producing a thermally insulating mixture comprising hydrophobic silica, in which a) a pulverulent carrier material selected from the group consisting of precipitated silicas, SiO.sub.2 aerogels, pearlites and mixtures thereof is coated with a liquid silicon compound, where the liquid silicon compound has at least one alkyl group and a boiling point of less than 200° C., and b) the pulverulent carrier material that has thus been coated with the liquid silicon compound is mixed with a composition comprising a pulverulent hydrophilic fumed silica and the mixture is subjected to thermal treatment at more than 40° C. and c) any unreacted silicon compound is subsequently removed from the thermally treated mixture, thus giving the thermally insulating mixture comprising hydrophobic silica.

A method for the production of a cavity filled with a low-density mineral foam includes (i) preparing a cement slurry including Portland cement; ultrafine particles of which the D50 is from 10 to 600 nm; a water reducing agent; a manganese salt; and water; wherein the mass ratio of manganese salts/Portland cement is below 0.014; (ii) adding to the cement slurry obtained after (i) a gas-forming liquid including a gas-forming agent; and a viscosity-modifying agent which is a polymer chosen among anionic bio-based polymer, amphiphilic bio-based polymer, alkali swellable acrylic polymer and mixture thereof; to obtain a foaming slurry; (iii) filling the cavity with the foaming slurry obtained at (ii); (iv) leaving the foaming slurry to expand within the cavity.

A method for the production of a cavity filled with a low-density mineral foam includes (i) preparing a cement slurry including Portland cement; ultrafine particles of which the D50 is from 10 to 600 nm; a water reducing agent; a manganese salt; and water; wherein the mass ratio of manganese salts/Portland cement is below 0.014; (ii) adding to the cement slurry obtained after (i) a gas-forming liquid including a gas-forming agent; and a viscosity-modifying agent which is a polymer chosen among anionic bio-based polymer, amphiphilic bio-based polymer, alkali swellable acrylic polymer and mixture thereof; to obtain a foaming slurry; (iii) filling the cavity with the foaming slurry obtained at (ii); (iv) leaving the foaming slurry to expand within the cavity.

Process for the production of a hydrophobic thermal-insulation moulding, where a hydrophilic thermal-insulation moulding is brought into contact with a hydrophobizing agent in vapour form with formation of a thermal-insulation moulding coated with hydrophobizing agent, and this is then subjected to a press process and during the press process and/or after the press process is reacted with the hydrophobizing agent with formation of the hydrophobic thermal-insulation moulding, where a) the density of the hydrophobic thermal-insulation moulding after the press process and after the reaction with the hydrophobizing agent is from 100 to 250 kg/m.sup.3, and b) the density of the hydrophilic thermal-insulation moulding on contact with the hydrophobizing agent is from 50% to less than 100% of the density of the hydrophobic thermal-insulation moulding.

Process for the production of a hydrophobic thermal-insulation moulding, where a hydrophilic thermal-insulation moulding is brought into contact with a hydrophobizing agent in vapour form with formation of a thermal-insulation moulding coated with hydrophobizing agent, and this is then subjected to a press process and during the press process and/or after the press process is reacted with the hydrophobizing agent with formation of the hydrophobic thermal-insulation moulding, where a) the density of the hydrophobic thermal-insulation moulding after the press process and after the reaction with the hydrophobizing agent is from 100 to 250 kg/m.sup.3, and b) the density of the hydrophilic thermal-insulation moulding on contact with the hydrophobizing agent is from 50% to less than 100% of the density of the hydrophobic thermal-insulation moulding.

Some embodiments of the present invention comprise a method of cementing comprising: placing a settable composition into a well bore, the settable composition comprising remediated coal ash, hydraulic cement, and water; and allowing the settable composition to set. Other embodiments comprise a method of cementing comprising: placing a settable composition into a well bore, the settable composition comprising remediated coal ash, calcium hydroxide (lime), and water; and allowing the settable composition to set. Other embodiments comprise a settable composition comprising: remediated coal ash, hydraulic cement, calcium hydroxide, natural pozzolan and water; and allowing the composition to set. Other embodiments comprise a settable composition comprising remediated coal ash and any combination of hydraulic cement, calcium hydroxide, slag, fly ash, and natural or other pozzolan.

Some embodiments of the present invention comprise a method of cementing comprising: placing a settable composition into a well bore, the settable composition comprising remediated coal ash, hydraulic cement, and water; and allowing the settable composition to set. Other embodiments comprise a method of cementing comprising: placing a settable composition into a well bore, the settable composition comprising remediated coal ash, calcium hydroxide (lime), and water; and allowing the settable composition to set. Other embodiments comprise a settable composition comprising: remediated coal ash, hydraulic cement, calcium hydroxide, natural pozzolan and water; and allowing the composition to set. Other embodiments comprise a settable composition comprising remediated coal ash and any combination of hydraulic cement, calcium hydroxide, slag, fly ash, and natural or other pozzolan.

The invention relates to a new inorganic polymer which is based on modified water glass, is characterized by numerous unusual properties and can be used as a substitute for, for example, concrete, cement, and ceramics.

The invention relates to a new inorganic polymer which is based on modified water glass, is characterized by numerous unusual properties and can be used as a substitute for, for example, concrete, cement, and ceramics.

An oxidation protection system disposed on a substrate is provided, which may comprise a base layer comprising a first pre-slurry composition comprising a first phosphate glass composition, and/or a sealing layer comprising a second pre-slurry composition comprising a second phosphate glass composition and a strengthening compound comprising boron nitride, a metal oxide, and/or silicon carbide.