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.

A method for preparing a silane coupling agent/silica/plant fiber composite includes the following steps: S1: pretreating plant fiber; S2: preparing hydrolysate of a silane coupling agent; S3: preparing a silane coupling agent/plant fiber composite; S4: preparing a silica nanoparticle dispersion; and S5: preparing a silane coupling agent/silica nanoparticle/plant fiber composite. Through the covalent interaction among a silanol group (Si—OH) formed by hydrolysis of the silane coupling agent, Si—OH of the silica, and a hydroxyl group (—OH) on the surface of the plant fiber, the present invention enables silica nanoparticles to be grafted on the surface of the plant fiber. Using a hydrophobic film formed by the silane coupling agent, harmful ions are prevented from invading, and the volume stability of the fiber is improved. Using the pozzolanic activity of the silica nanoparticles, the alkalinity and calcium hydroxide content around the fiber are reduced.

Methods for preparing a carbonated supplementary cementitious materials, including semi-wet carbonation, cyclic carbonation, non-slurry carbonation, high temperature carbonation and/or granular carbonation of a carbonatable material.

Methods of preparing engineered cementitious composite precursors include carbonating a fly ash comprising >about 25% by weight of calcium oxide (CaO) and having a water content of >about 12% to <about 18% by weight of water by exposing the fly ash to a first gas stream comprising carbon dioxide to form a carbonated fly ash. A steel slag is also carbonated that comprises >about 40% by weight of calcium oxide (CaO) and having a water content of >about 12% to <about 18% by weight of water by exposing the steel slag to a second gas stream comprising carbon dioxide to form a carbonated steel slag. The carbonated fly ash and the carbonated steel slag are suitable for use as engineered cementitious composite precursors in a bendable engineered cementitious composite composition that further comprises Portland cement, a polymeric fiber, and a superplasticizer.

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.

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.

The present invention relates to additives and, more specifically, the use of biochar, in concrete and other cementitious materials to provide for building materials that have a lower carbon footprint than their traditional counterparts. Traditional methods for production of cement produce large amount of carbon dioxide (CO2). When coupled with the massive demand for cement building materials around the world, this means that the cement production has a significant impact on the amount of CO2 produced globally. By including biochar and other additives along with, or instead of some traditional components of cement, one may be able to provide for cementitious building materials that sequester carbon, rather than release it.

The present invention relates to the field of cementitious compositions. Particularly, the invention concerns an alkaline-activated fly ash cementitious composition and the use of this composition as a binder in concrete production.

The invention relates to an environment-friendly artificial stone with low cost and high strength and a preparation method thereof, the artificial stone comprises the following raw materials in parts by mass: 60-80 parts of fritted sand; 10-30 parts of quartz powder; 9-14 parts of terephthalic unsaturated polyester resin; 0.6-1 parts of curing agent; 0.8-1 parts of coupling agent; 0.5-1 parts of pigment paste; 0.1-1 parts of pigment powder. The invention has advantages of: (1) using mine solid waste or waste materials as raw materials, and using blast-furnace gas and coke-oven gas recovered and purified in the productive process of the steel plant and coking plant as fuel, the production process is green and environment-friendly, which can recycle waste materials. (2) high strength, natural stripe, elegance appearance, green and environmental protection, and being recognized by global customers and promising in worldwide market.

The present invention relates to the process of producing artificial aggregate from tailings from ore dams. The iron ore sandy tailings are mixed with a binder and, through the mixing and pelletizing process, form the artificial aggregate. The artificial aggregate produced has a spheroidal shape, a large size, a rough surface and a color that ranges between pink and dark red. This artificial aggregate is able to replace the natural aggregate, and can be used in the manufacture of a more resistant concrete, for the base and sub-base of roads, as a decorative element for gardens and beds, in addition to being a form of storage of ore dam tailings in the form of pellets, adding value to these tailings and reducing the environmental mining impacts.