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.

The invention relates to a method (100) for selecting the composition of a construction material including an excavated clay soil, said construction material composition to include deflocculating agent and activating agent quantities adapted to the excavated clay soil, said method including a step of receiving (130) a measured value of at least one physicochemical property of an excavated clay soil, and a step of selecting (170) a deflocculating agent quantity and an activating agent quantity adapted to the excavated clay soil. In addition, the invention also relates to a method (200) for calibrating a calculation algorithm for determining the composition of a site construction material, to a construction material formed from an excavated clay soil, and to a system (400) for preparing a construction material including an excavated clay soil.

Method and installation for calcining cement raw meal in a calciner whereby fuel and a calciner oxidant having an oxygen content of at least 30% vol are introduced into the calciner so as to generate either an oxidant-lean zone or a fuel-lean zone in the calciner located between the lowermost fuel inlet level and the lowermost oxidant inlet level of the calciner, between 50% and 100% by weight of the raw meal being supplied to the calciner upstream of and/or within the oxidant-lean, respectively the fuel-lean zone.

Provided herein are compositions, methods, and systems comprising vaterite and magnesium oxide.

Method and equipment for conditioning wet concrete (703), the wet concrete (703) being agitated in a revolving-drum concrete mixer (702), thereby bringing changing portions of the wet concrete (703) to a free surface (706) of the wet concrete (703) inside the mixer (702), the agitated wet concrete (703) being cooled and partially carbonated in that liquid and/or solid carbon dioxide is supplied to the concrete mixer (702) simultaneously with liquid nitrogen so that both the supplied nitrogen and the supplied carbon dioxide contact the free surface (706) of the wet concrete (703).

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 makes 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 method of curing a low Ca/Mg cement composition is described that includes providing a predetermined quantity of the low Ca/Mg cement composition in uncured form; and reacting the uncured low Ca/Mg cement composition with a reagent chemical for a time sufficient to cure said cementitious material, wherein said reagent chemical is a compound synthesized from CO.sub.2 and comprises dicarboxylic acids, tricarboxylic acids, or alpha-hydroxycarboxylic acids.

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 method for making a carbonated precast concrete product includes: obtaining a mixture including at least one binder material, an aggregate, and water; molding the mixture into a molded intermediate; demolding the molded intermediate to obtain a demolded intermediate, the demolded intermediate having a first water-to-binder ratio; conditioning the demolded intermediate to provide a conditioned article having a second water-to-binder ratio less than the first water-to-binder ratio of the demolded intermediate; moisturizing at least one surface of the conditioned article with an aqueous medium, thereby causing a weight gain of the conditioned article and providing a moisturized product, a first portion of the moisturized product having a third water-to-binder ratio greater than a fourth water-to-binder ratio of a remainder of the moisturized product; and curing the moisturized product with carbon dioxide to obtain the carbonated precast concrete product.

In a method for supplying oxygen-enriched gas to an oxygen consuming process, in which the oxygen-enriched gas with a low nitrogen content is generated by supplying an anode-side feed gas comprising CO.sub.2 to the anode side of a solid oxide electrolysis cell, oxygen is generated on the anode side of the solid oxide electrolysis cell. This way, an anode-side product gas is formed, in which the oxygen-enriched gas comprises at least a part. The oxygen-enriched gas has a low nitrogen content, and the temperature of the oxygen-enriched gas exiting the solid oxide electrolysis cell is between 600 and 1000° C. The method has multiple advantages, first of all as regards energy saving.