It has been unexpected found that the machinability and corrosion resistance of powder metal parts can be greatly improved by incorporating calcium aluminoferrite powder, such as naturally occurring brownmillerite powder (Ca.sub.2(Al,Fe).sub.2O.sub.5), into the part. Improved machinability is of enormous value in manufacturing countless parts where it is necessary or desirable to machine the part after it has been sintered, such as is frequently the case with gears, rotors and sprockets. In the practice of this invention, calcium aluminoferrite powder can also be incorporated into parts which will not necessarily be machined for the sole purpose of attaining better corrosion resistance. Surprisingly, the incorporation of the calcium aluminoferrite powder into such parts does not significantly compromise the strength, durability, or wear characteristics of the part and generally improves the service life of the part by providing better corrosion resistance.

A method of manufacturing a concrete product includes providing a metal-based cementing agent including at least one of Fe.sub.2O.sub.3 and Fe.sub.3O.sub.4, an aqueous phosphoric acid cement reacting agent, an aggregate having at least one metallic oxide, a setting agent including at least one of Fe.sup.+2 and Mn.sup.+2, and an acid scavenging agent including at least one of K-feldspar and magnesium silicate. The method includes mixing the metal-based cementing agent, the cement reacting agent, the aggregate, the setting agent and the acid scavenging agent together to form a liquid concrete mixture, and placing the liquid concrete mixture in a form and allowing the liquid concrete mixture to set up and cure into the concrete product. The method can optionally include the additional step of placing the concrete product into an oven at a temperature of between 170 and 190 C.

A method of manufacturing a concrete product includes providing a metal-based cementing agent including at least one of Fe.sub.2O.sub.3 and Fe.sub.3O.sub.4, an aqueous phosphoric acid cement reacting agent, an aggregate having at least one metallic oxide, a setting agent including at least one of Fe.sup.+2 and Mn.sup.+2, and an acid scavenging agent including at least one of K-feldspar and magnesium silicate. The method includes mixing the metal-based cementing agent, the cement reacting agent, the aggregate, the setting agent and the acid scavenging agent together to form a liquid concrete mixture, and placing the liquid concrete mixture in a form and allowing the liquid concrete mixture to set up and cure into the concrete product. The method can optionally include the additional step of placing the concrete product into an oven at a temperature of between 170 and 190 C.

Provided herein are methods and compositions utilizing one or more cementitious replacement materials, one or more alkaline activating materials, and, optionally one or more bonding materials and/or one or more setting time enhancer materials.

The present invention patent refers to a method of obtaining a clay composition activated/calcined with a fraction of calcium aluminoferrite or calcium ferrite and clay composition obtained by the aforementioned method, more precisely belonging to the field of industrial cement manufacturing, where said method discloses a process of forming calcium aluminoferrite or calcium ferrite in-situ to deliver an activated/calcined clay from red clay that is most appreciated for adding to a cement composition.

A method of manufacturing a concrete product includes providing a metal-based cementing agent including at least one of Fe.sub.2O.sub.3 and Fe.sub.3O.sub.4, an aqueous phosphoric acid cement reacting agent, an aggregate having at least one metallic oxide, a setting agent including at least one of Fe.sup.+2 and Mn.sup.+2, and an acid scavenging agent including at least one of K-feldspar and magnesium silicate. The method includes mixing the metal-based cementing agent, the cement reacting agent, the aggregate, the setting agent and the acid scavenging agent together to form a liquid concrete mixture, and placing the liquid concrete mixture in a form and allowing the liquid concrete mixture to set up and cure into the concrete product. The method can optionally include the additional step of placing the concrete product into an oven at a temperature of between 170 C. and 190 C.

A method of manufacturing a concrete product includes providing a metal-based cementing agent including at least one of Fe.sub.2O.sub.3 and Fe.sub.3O.sub.4, an aqueous phosphoric acid cement reacting agent, an aggregate having at least one metallic oxide, a setting agent including at least one of Fe.sup.+2 and Mn.sup.+2, and an acid scavenging agent including at least one of K-feldspar and magnesium silicate. The method includes mixing the metal-based cementing agent, the cement reacting agent, the aggregate, the setting agent and the acid scavenging agent together to form a liquid concrete mixture, and placing the liquid concrete mixture in a form and allowing the liquid concrete mixture to set up and cure into the concrete product. The method can optionally include the additional step of placing the concrete product into an oven at a temperature of between 170 C. and 190 C.

A method for thermal activation of coal gangue and in-situ carbon fixation utilizing waste heat from steel slag is disclosed. By utilizing waste heat from high-temperature molten steel slag, coal gangue is activated to a high pozzolanic activity utilizing the system temperature of a steel slag hot-steaming device, and meanwhile, the CO.sub.2 released in the thermal activation process is captured utilizing the reaction of steel slag with CO.sub.2 to generate stable carbonates, thus achieving permanent carbon sequestration. The present disclosure effectively uses the heat from the hot steel slag discharged from the steelmaking furnace in such a way that the coal gangue is activated while the steel slag undergoes a carbonation reaction, resulting in an increased heat recovery rate during the cooling process of the steel slag.

A method for thermal activation of coal gangue and in-situ carbon fixation utilizing waste heat from steel slag is disclosed. By utilizing waste heat from high-temperature molten steel slag, coal gangue is activated to a high pozzolanic activity utilizing the system temperature of a steel slag hot-steaming device, and meanwhile, the CO.sub.2 released in the thermal activation process is captured utilizing the reaction of steel slag with CO.sub.2 to generate stable carbonates, thus achieving permanent carbon sequestration. The present disclosure effectively uses the heat from the hot steel slag discharged from the steelmaking furnace in such a way that the coal gangue is activated while the steel slag undergoes a carbonation reaction, resulting in an increased heat recovery rate during the cooling process of the steel slag.