Abstract: Coal is combusted in the presence of a clay additive and a slag additive to produce a combustion product that is useful as a pozzolanic additive for cement. The combustion process may be performed in a coal-fired boiler of an electrical power generation plant, resulting in improved operational efficiency and controlled emissions.
Abstract: A method and system for producing modified coal combustion products are disclosed. The additives reduce the particle sizes of the coal combustion product and may reduce the amount of un-burned carbon in the coal combustion product, making the modified product useful as an addition to cementitious materials.
Abstract: The present invention provides combustion products of hydrocarbon fuels and controlled amounts of metal oxide strength enhancing materials. The combustion products are useful as additives to cementitious materials. A hydrocarbon fuel such as coal is introduced into a combustion chamber and selected amounts of materials comprising CaO, SiO2 and Al2O3 are also introduced into and/or downstream from the chamber. The hydrocarbon fuel undergoes combustion while the metal oxide strength enhancing materials react with each other and/or the ash or other reaction products of the hydrocarbon fuel. The combustion products have been found to significantly increase compressive strengths of cements such as Portland cement. A reduction in SO2 emission levels also results from the introduction of the metal oxide strength enhancing materials into the combustion process.
Abstract: A method and system for producing modified coal combustion products are disclosed. The additives reduce the particle sizes of the coal combustion product and may reduce the amount of un-burned carbon in the coal combustion product, making the modified product useful as an addition to cementitious materials.
Abstract: In-process systems and methods for treating coal combustion products with property-enhancing additives are disclosed. Coal combustion products such as fly ash are collected upon their formation and are contemporaneously treated with additives such as dispersants, rheology modifiers, retarders and accelerators to improve properties of the treated products when they are used in cement, concrete, mortar and other hydraulic mixtures.
Abstract: A method and system for reducing the un-burned carbon content in coal combustion products are disclosed. A coal combustion product is separated into a coarse particle fraction and a fine particle fraction, and the coarse particles are comminuted by milling, grinding or the like. Additives may be added of the coarse particles prior to comminution. The comminuted particles are then co-combusted with coal to burn at least a portion of the un-burned carbon contained in the original coal combustion product.
Abstract: The present invention provides combustion products of hydrocarbon fuels and controlled amounts of metal oxide strength enhancing materials. The combustion products are useful as additives to cementitious materials. A hydrocarbon fuel such as coal is introduced into a combustion chamber and selected amounts of materials comprising CaO, SiO2 and Al2O3 are also introduced into and/or downstream from the chamber. The hydrocarbon fuel undergoes combustion while the metal oxide strength enhancing materials react with each other and/or the ash or other reaction products of the hydrocarbon fuel. The combustion products have been found to significantly increase compressive strengths of cements such as Portland cement. A reduction in SO2 emission levels also results from the introduction of the metal oxide strength enhancing materials into the combustion process.