An ozonation-based method for producing a cementitious material comprises the steps of: (1) mixing a flue gas with an ozone-containing gas to form a mixed flue gas; and introducing the mixed flue gas into an absorption tower, where the mixed flue gas undergoes dry desulfurization and denitrification by reacting with a powdered desulfurizing and denitrificating agent and becomes a treated flue gas; (2) subjecting the treated flue gas to dust removal to generate by-products; and (3) uniformly mixing raw materials that comprise the first by-product, magnesium oxide, fly ash and an additive to give a cementitious material, wherein on the basis of 100 parts by weight of the cementitious material, the first by-product is 20-60 parts by weight, magnesium oxide is 16-33 parts by weight, the fly ash is 15-35 parts by weight, and the additive is 1-15 parts by weight.

An ozonation-based method for producing a cementitious material comprises the steps of: (1) mixing a flue gas with an ozone-containing gas to form a mixed flue gas; and introducing the mixed flue gas into an absorption tower, where the mixed flue gas undergoes dry desulfurization and denitrification by reacting with a powdered desulfurizing and denitrificating agent and becomes a treated flue gas; (2) subjecting the treated flue gas to dust removal to generate by-products; and (3) uniformly mixing raw materials that comprise the first by-product, magnesium oxide, fly ash and an additive to give a cementitious material, wherein on the basis of 100 parts by weight of the cementitious material, the first by-product is 20-60 parts by weight, magnesium oxide is 16-33 parts by weight, the fly ash is 15-35 parts by weight, and the additive is 1-15 parts by weight.

Disclosed is a hydraulically and chemically bonding refractory cement, which includes a caustic magnesia component having a BET specific surface area of at least 0.5 m.sup.2/g, and a carboxylic acid component, wherein the carboxylic acid component consists of at least one carboxylic acid that is only slightly water soluble and/or has a low dissolution rate in aqueous solutions, and which carboxylic acid component is capable of generating at least one soluble magnesium salt upon contact of the cement with water. Also disclosed is a corresponding refractory material containing the magnesia cement and to uses thereof for the manufacture of products useful in various industries.

Disclosed is a hydraulically and chemically bonding refractory cement, which includes a caustic magnesia component having a BET specific surface area of at least 0.5 m.sup.2/g, and a carboxylic acid component, wherein the carboxylic acid component consists of at least one carboxylic acid that is only slightly water soluble and/or has a low dissolution rate in aqueous solutions, and which carboxylic acid component is capable of generating at least one soluble magnesium salt upon contact of the cement with water. Also disclosed is a corresponding refractory material containing the magnesia cement and to uses thereof for the manufacture of products useful in various industries.

Disclosed is a hydraulically and chemically bonding refractory cement, which includes a caustic magnesia component having a BET specific surface area of at least 0.5 m.sup.2/g, and a carboxylic acid component, wherein the carboxylic acid component consists of at least one carboxylic acid that is only slightly water soluble and/or has a low dissolution rate in aqueous solutions, and which carboxylic acid component is capable of generating at least one soluble magnesium salt upon contact of the cement with water. Also disclosed is a corresponding refractory material containing the magnesia cement and to uses thereof for the manufacture of products useful in various industries.

Lightweight molding produced from a dry mixture including graphite particles and a binder for setting of the dry mixture by water, alkali and/or aqueous salt solution, where the proportion by mass of the graphite particles in the dry mixture is more than 0.05, the binder includes magnesia binder, cement, caustic calcined magnesite, lime and/or clay powder, the density of the lightweight molding is in the range from 0.1 g/cm.sup.3 to 3.5 g/cm.sup.3 and the lightweight molding has a thermal conductivity of at least 0.5 W/mK.

Lightweight molding produced from a dry mixture including graphite particles and a binder for setting of the dry mixture by water, alkali and/or aqueous salt solution, where the proportion by mass of the graphite particles in the dry mixture is more than 0.05, the binder includes magnesia binder, cement, caustic calcined magnesite, lime and/or clay powder, the density of the lightweight molding is in the range from 0.1 g/cm.sup.3 to 3.5 g/cm.sup.3 and the lightweight molding has a thermal conductivity of at least 0.5 W/mK.

Lightweight molding produced from a dry mixture including graphite particles and a binder for setting of the dry mixture by water, alkali and/or aqueous salt solution, where the proportion by mass of the graphite particles in the dry mixture is more than 0.05, the binder includes magnesia binder, cement, caustic calcined magnesite, lime and/or clay powder, the density of the lightweight molding is in the range from 0.1 g/cm.sup.3 to 3.5 g/cm.sup.3 and the lightweight molding has a thermal conductivity of at least 0.5 W/mK.

A composition for use in making a structural assembly board, a structural assembly made from the composition, and a method of making the structural assembly board is provided. The composition includes magnesium oxide; magnesium sulfate; and water. The composition includes reinforcing fibers. The composition and method of making the structural assembly board promote formation of 5MgO.MgSO.sub.4.2H.sub.2O to improve structural qualities of the structural assembly board.

A composition for use in making a structural assembly board, a structural assembly made from the composition, and a method of making the structural assembly board is provided. The composition includes magnesium oxide; magnesium sulfate; and water. The composition includes reinforcing fibers. The composition and method of making the structural assembly board promote formation of 5MgO.MgSO.sub.4.2H.sub.2O to improve structural qualities of the structural assembly board.