A process of sequestering CO.sub.2 is generally described. The process involves the use of geopolymeric precursors to which the CO.sub.2 is added. The process for a solid, cementitious material comprising geopolymer(s) and CO.sub.2.

This geopolymer molding production method comprises: a mixing step (S1) for mixing a first material containing aluminum and silicon with a hydrate of an alkali stimulant containing a hydrate of an alkaline hydroxide and/or a hydrate of an alkaline silicate; a compaction step (S2) for compacting the mixture obtained in the mixing step (S1) into a compacted mixture; and a curing step (S3) for curing the compacted mixture.

A geopolymer cementing fluid with controllable thickening time includes the following components in parts by weight: 100 parts of a cementitious material, 10 parts-30 parts of an activator, 0.2 parts-5 parts of a retarder, 0.4 parts-4 parts of an anti-settling agent, and 30 parts-70 parts of water. The geopolymer cementing fluid of the present invention has the advantages of controllable thickening time, excellent compressive strength, good settlement stability, good rheological properties, green and eco-friendly, and the like. The geopolymer cementing fluid can be better suited for the operations of oil and gas well cementing and ensure cementing safety.

The invention comprises a cementitious material comprising a natural pozzolan selected from hyaloclastite, sideromelane or tachylite, wherein the natural pozzolan has a volume-based mean particle size of less than or equal to 40 μm. The cementitious material also comprising an aqueous alkaline activating solution suitable for forming a geopolymer. A method making a cementitious material is also disclosed.

Improved cement for concrete is provided having reduced carbon footprint and improved mechanical properties. A limestone-free process of making the clinker provides a 70% reduction of carbon footprint vs. conventional manufacture of Portland cement. Curing the resulting cement in a temperature range from 80° C. to 100° C. advantageously enhances growth of fibrous minerals in the concrete.

The invention relates to a geopolymer grout for protecting prestressing reinforcements, the geopolymer grout comprising metakaolin, fly ash and an activator mixture, the activator mixture comprising sodium hydroxide and sodium silicate, wherein the molar ratio Na.sub.2O:SiO.sub.2 of the sodium silicate is between 0.40 and 0.70.

A geopolymer thermal energy storage (TES) concrete product comprising at least one binder; at least one alkali activator; at least one fine aggregate with high thermal conductivity and heat capacity; and at least one coarse aggregate with high thermal conductivity and heat capacity.

Described are cementitious reagent materials produced from globally abundant inorganic feedstocks. Also described are methods for the manufacture of such cementitious reagent materials and forming the reagent materials as microspheroidal glassy particles. Also described are apparatuses, systems and methods for the thermochemical production of glassy cementitious reagents with spheroidal morphology. The apparatuses, systems and methods make use of an in-flight melting/quenching technology such that solid particles are flown in suspension, melted in suspension, and then quenched in suspension. The cementitious reagents can be used in concrete to substantially reduce the CO.sub.2 emission associated with cement production.

A vegetal concrete masonry unit is provided which comprises cooked crop residues, binder and pulverized fuel ash in a mass ratio of 1:1:1.5 to 1:1.5:3.

Methods of forming synthetic aluminosilicate material are disclosed. Exemplary methods include forming a polymer solution, adding an aluminum precursor to the polymer solution, adding a silicon precursor to the polymer solution, forming a gel from the polymer solution, calcining the gel to form an aluminosilicate powder, and grinding the aluminosilicate powder to form ground aluminosilicate material. The synthetic aluminosilicate material can be used in the formation of cement and concrete.