According to some embodiments, a curable mixture configured to set in the presence of water, wherein the mixture comprises magnesium oxide, a primary cementitious component and at least one accelerant. A proportion by weight of the primary cementitious component is 80% to 120% of a proportion of magnesium oxide by weight.

According to some embodiments, a curable mixture configured to set in the presence of water, wherein the mixture comprises magnesium oxide, a primary cementitious component and at least one accelerant. A proportion by weight of the primary cementitious component is 80% to 120% of a proportion of magnesium oxide by weight.

A method of manufacturing a composition with hierarchical nanochemical bonding includes making a powder of one or more oxygen containing materials; mixing the powder either with a water solution of organic and/or inorganic acid to form an acidic slurry, or with water to form a hydrated basic slurry; and curing the slurry to form a solid. The powder comprises nanoscale particles, or microscale particles, or a mixture of nanoscale particles and microscale particles.

A delayed-expansion cement mixture or slurry of hydraulic cement contains an expanding agent having hydrophobically modified surfaces with a hydrophobic and/or self-assembling film. A method to delay expansion of cement involves treating the expanding agent with a self-assembling film precursor compound, making the slurry with cement and water, and setting and expanding the cement. A cementing method places the mixture or slurry downhole where it is hardened and expanded.

A delayed-expansion cement mixture or slurry of hydraulic cement contains an expanding agent having hydrophobically modified surfaces with a hydrophobic and/or self-assembling film. A method to delay expansion of cement involves treating the expanding agent with a self-assembling film precursor compound, making the slurry with cement and water, and setting and expanding the cement. A cementing method places the mixture or slurry downhole where it is hardened and expanded.

A method for manufacturing green or thermally treated briquettes which are made up of at least one quick calcium-magnesium compound that is an iron-based compound. The method includes the steps of supplying a homogeneous pulverulent mixture to a roller press, the press having pockets where the pulverulent mixture is compressed to form the green briquettes. The rollers of the roller press develop linear speeds at the periphery of the rollers between 10 and 100 cm/s and linear pressures between 60 and 160 kN/cm. The method can also include a thermal treatment of the green briquettes to produce fired briquettes containing calcium ferrite, the briquettes having a Shatter Test Index less than 8%, and a porosity value greater than or equal to 30%.

A method for manufacturing green or thermally treated briquettes which are made up of at least one quick calcium-magnesium compound that is an iron-based compound. The method includes the steps of supplying a homogeneous pulverulent mixture to a roller press, the press having pockets where the pulverulent mixture is compressed to form the green briquettes. The rollers of the roller press develop linear speeds at the periphery of the rollers between 10 and 100 cm/s and linear pressures between 60 and 160 kN/cm. The method can also include a thermal treatment of the green briquettes to produce fired briquettes containing calcium ferrite, the briquettes having a Shatter Test Index less than 8%, and a porosity value greater than or equal to 30%.

A composition consisting essentially of (a) 1 to 30% by weight of a 1 to 90% by weight aqueous phosphoric acid and/or a hydrogen phosphate; (b) 1 to 40% by weight of a compound selected from the group of oxides, hydroxides and oxide hydrates of magnesium, calcium, iron, zinc and copper; (c) 40 to 95% by weight of a particulate filler selected from the group of glass; mono-, oligo- and polyphosphates of magnesium, calcium, barium and aluminium; calcium sulphate; barium sulphate; simple and complex silicates; simple and complex aluminates; simple and complex titanates; simple and complex zirconates; zirconium dioxide; titanium dioxide, aluminium oxide; silicon oxide; silicon carbide; aluminium nitride; boron nitride and silicon nitride; (d) 1 to 10% by weight of an urea compound selected from the group consisting of imidazolidine-2-on, allantoin and imidazolidinyl urea; and (e) 0 to 15% by weight of a component differing from (a) to (d).

Methods to prepare a well cementing slurry include coating particles comprising an expanding agent with a component selected from the group consisting of a phenolic resin, a silica, a calcination product of a polysiloxane oil, and a combination thereof; and combining the coated particles with mix water and hydraulic cement to form a cement slurry for cementing a well.

Methods to prepare a well cementing slurry include coating particles comprising an expanding agent with a component selected from the group consisting of a phenolic resin, a silica, a calcination product of a polysiloxane oil, and a combination thereof; and combining the coated particles with mix water and hydraulic cement to form a cement slurry for cementing a well.