The invention relates to a method for producing supersulfated cement, wherein pozzolanic and hydraulic aluminosilicate components and a calcium-sulfate-alkaline activation complex are mixed together. The calcium-sulfate-alkaline activation complex is produced by carrying out the following successive steps: a first step of mixing 70% by weight of calcium sulfate and 30% by weight of alkaline components; and subsequently; a second step of thermodynamically activating, by hot quenching, the calcium-sulfate-alkaline activation complex; and subsequently; a third step of cold quenching, by rapid mixing, the activated calcium-sulfate-alkaline activation complex with the pozzolanic aluminosilicate components.

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.

A method of providing a reactive cement constituent or concrete additive includes at least the following steps: a) reworking a carbon-containing heap comprising at least coal and clay-bearing rock; b) extracting at least calcined rock; c) producing fine-grain calcined rock; and d) providing fine-grain calcined rock for use as cement constituent or concrete additive.

Provided herein are methods and systems to form calcium carbonate comprising vaterite, comprising dissolving limestone in an aqueous base solution under one or more precipitation conditions to produce a precipitation material comprising calcium carbonate and a supernatant solution, wherein the calcium carbonate comprises vaterite.

A method/system for sequestering carbon dioxide from cement and lime production facilities wherein carbon dioxide from flue gases originating from cement or lime production facilities is recovered and transported to a building materials production facility where it is sequestered.

A concrete composition that includes (i) a treated palm oil fuel ash, wherein the treated palm oil fuel ash is the only binder present, (ii) a fine aggregate, (iii) a coarse aggregate, and (iv) an alkali activator containing an aqueous solution of sodium hydroxide and sodium silicate. A cured concrete made from the concrete composition is also disclosed with advantageous compressive strength properties.

A high-silica-containing supplemental cementitious materials, and a method of producing same. This material undergoes a pozzolanic reaction during hydration in a mixture of Ordinary Portland Cement (OPC) or lime.

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.

A method of processing exhaust gas containing CO.sub.2, such as exhaust gas from a cement production plant, includes burning fuel in the combustion reactor with the O.sub.2 content of the exhaust gas being used as an oxidizing agent, controlling the combustion in the combustion reactor so that the exhaust gas from the combustion reactor contains less than 10 vol.-% of oxygen and at least 80 vol.-% of a mixture of CO and CO.sub.2, and feeding the exhaust gas from the combustion reactor into a conversion reactor, in which the CO.sub.2 and optionally the CO contained in the exhaust gas is converted into a hydrocarbon fuel.

Calcium silicate-based cements and concretes are disclosed, which result in concrete compositions that have an increased durability. A cement product includes a plurality of particles of a carbonatable calcium silicate cement and a hydrophobic organic acid, or a salt thereof, or a silane, or a polysiloxane.