TECHNOLOGY FOCUS - CERAMICS AND GLASS - Preferred Method: The cementitious slag partly or totally replaces Portland cement production, and avoided carbon dioxide emission from Portland cement kilns is credited to the air-cooled, slagging combustor operation. The method uses refuse derived fuel from municipal waste or its char or shredded waste paper which is co-fired at mass flow rates of less than or equal to 20% with coal char, or coal culm or carbon content fly ash in an air-cooled slagging combustor under conditions for near total emission control and CO2 sequestration. The refuse derived fuel is gasified indirectly in shell and tube heat exchangers for conversion to hydrogen or methane with remaining char co-fired in the air-cooled slagging combustor. The carbon dioxide in combustion gas exhaust is dissolved in water to form carbonic acid, which is compressed and injected into underground limestone formations below potable water depths for permanent sequestration as calcium bicarbonate. The cementitious slag produced is processed in stand-alone power plants comprising air-cooled slagging combustor-boilers placed adjacent to central station coal power plants to process all the ash generated by the power plant. The cementitious slag is implemented in slagging combustor-boiler power plants that are erected on Ocean islands, and carbon dioxide from the combustion gases which is converted into calcium bi-carbonate emulsions for injection into the Ocean and the cementitious slag is used for seawall construction off the island's shore. The method is implemented in power plants comprising air-cooled slagging combustor-boilers that are placed near underground limestone formations to eliminate a need to transport gaseous or liquid carbon dioxide to limestone sequestration sites. The anthracite culm or coal mine waste located on or beneath a surface or in active or abandoned mine sites is used in air-cooled slagging combustor power plants erected at the mine or at underground limestone or saline formations for carbon dioxide sequestration, and including co-production of the cementitious slag and electricity. The emissions of nitrogen oxides (NOx), SO2, hazardous trace metals in coal or coal ash, dioxins and furans, are controlled in the air-cooled slagging combustor and in post-combustion zones upstream of where amines or ammonia are injected to separate carbon dioxide from the exhaust gases, or where physical separation of CO2 from the combustion gas exhaust takes place. In the method, mountaintop mining is implemented by digging vertical pits from a mountain top to coal seams, and combining a mineral part of overburden including at least one of silicon oxide, aluminum oxide, iron oxide, magnesium oxide, with at least 25% of the extracted coal for combustion in air cooled slagging combustor boilers to convert the mixture into the cementitious slag. The disfiguring mountaintop mining and discharging mined solid or liquid waste down the mountain is eliminated by drilling vertical pits of diameter sufficient to lower remote controlled mining machinery to extract the coal horizontally from the coal seams in a manner similar to radial horizontal underground oil or gas extraction. The carbon dioxide produced during fossil fuel combustion is chemically bound to processed serpentinite for carbon dioxide sequestration primarily in regions that are in close proximity to serpentinite geologic formations. The carbon dioxide is liquefied to pressures of 3500 psi for cracking in underground shale formations to release natural gas trapped in the shale formations, and following surface recovery of the carbon dioxide and natural gas and separation from each other, the carbon dioxide is re-pressurized above 3500 psi, mixed with water to form carbonic acid and re-injected into limestone formations at greater depth than the shale formation for sequestration as calcium bi-carbonate. The method injects CO2 for sequestration into depleted oil or gas wells continues until a total volume of liquid CO2 injected fills a void left after oil or gas was previously removed from the wells, and following complete filling of the void, any oil or gas that is subsequently extracted due to the injection of additional liquid carbon dioxide for use in combustion systems, where resultant emissions of carbon dioxide will be charged to an owner, seller, or user of the combusted oil or gas. The method injects hydrogen produced from coal volatile matter in a post-combustion zone of coal char, or culm, or carbon-fly ash, or solid waste fuel boiler to reduce at least nitrogen oxides and sulfur dioxide. The method attaches coal power plants comprising air-cooled slagging combustor to boilers which are erected at or near sub-bituminous or lignite coalmines in Montana, Wyoming, North and South Dakota, have their carbon dioxide exhaust dissolved in water to form carbonic acid and injected into Madison limestone formations that underlie the States, and have their electricity output transmitted to industrial and/or population centers, and which is implemented in areas that have similar coal and limestone formations.