The invention provides compositions and methods for controlling setting of carbonatable calcium silicate compositions that are contaminated with hydrating materials. These carbonatable calcium silicate cements are suitable for use as non-hydraulic cement that hardens by a carbonation process and may be applied in a variety of concrete components in the infrastructure, construction, pavement and landscaping industries.

The invention provides compositions and methods for controlling setting of carbonatable calcium silicate compositions that are contaminated with hydrating materials. These carbonatable calcium silicate cements are suitable for use as non-hydraulic cement that hardens by a carbonation process and may be applied in a variety of concrete components in the infrastructure, construction, pavement and landscaping industries.

A fire-proof material, in particular a fire-proof thermal insulation material containing water glass, which is composed of a compound which contains 34 to 49.9 wt % of inorganic non-flammable fibres, 50 to 65 wt % of an aqueous silicate solution, and 0.1 to 1 wt % of water glass stabiliser, while it further contains a water glass hardener and the aqueous silicate solution has a density in the range of 1370 to 1400 kg/m.sup.3 and a molar ratio of SiO.sub.2 to Na.sub.2O in the range of 3.2 to 3.4.

An environmentally friendly composition of matter comprising a limestone and fiberglass based waste material used to substitute out a portion of natural aggregate with said waste material so as to preserve natural resources, protect the environment and prevent depletion of landfill capacity and reuse unusable waste products into environmentally useful products.

Provided are an energy-saving and environment-friendly non-autoclaved pipe pile concrete material with high impact resistance, and a preparation method thereof. Raw materials of the concrete include cementing material, sand and gravels, modified rubber fiber, water reducer and water. The rubber fiber comes from waste tires. The cementing material includes cement, slag powder and silicon powder. A content of the cementing material in the concrete is 400-500 kg/m.sup.3. A water-cement ratio is 0.19-0.22. A specific surface area of the slag powder is 400-450 m.sup.2/kg. A content ratio of the slag power to the whole cementing material by mass is 25-40%. A specific surface area of the silicon powder is 15-30 m.sup.2/kg. A content ratio of the silicon power to the whole cementing material by mass is 5-10%. The modified rubber fiber is obtained by making the rubber fiber undergo shallow carbonization and soaking the obtained rubber fiber with a modifier.

Cement compositions that can capture carbon dioxide and related methods are generally described.

A hybrid magnesium cement composition formed from an A-side component and a B-side component. The A-side component includes an A1-component including a light-burn grade magnesium-containing material, and an A2-component including a non-metallic oxide salt. A B-side component having a metal silicate polymer is included.

The present disclosure generally relates to scavenging hydrogen sulfide. The disclosure pertains to non-aqueous and non-volatile compositions that include a monolignol alcohol and hydrogen sulfide scavenging compound. The hydrogen sulfide scavenging compound may be hexamine in some aspects. The compositions may also include a C.sub.2-8 polyol. The compositions disclosed are stable and can be used, for example, in removing hydrogen sulfide from hot asphalt.

A calcium-containing composition with fixed CO.sub.2 is produced by contacting a mixture of a calcium-containing composition before CO.sub.2 fixation and water with a CO.sub.2-containing gas. The calcium-containing composition, liquid water, and the CO.sub.2-containing gas having a temperature between 20 degree Celsius and 300 degree Celsius and a CO.sub.2 concentration between 1 volume % and 100 volume % are supplied to a reactor. By the supplied CO.sub.2-containing gas, the calcium-containing composition and water are made to flow in the reactor. Alternatively, the calcium-containing composition and water are in the reactor. Thus, CO.sub.2 is fixed in the calcium-containing composition and simultaneously the calcium-containing composition is dried to a water content of 5 mass % or less.

A method of preparing alkali-activated cement by stepwise calcination with sodium chloride includes the following steps. (1) Sodium chloride, a silicate and a carbonate are mixed and finely ground to obtain a raw material powder. (2) The raw material powder is calcined sequentially at 850-1050? C. and 1240? C. or more, and cooled to obtain a clinker. (3) The clinker is mixed with at least one of sodium hydroxide and potassium hydroxide, and ground finely to produce a cement powder.