A method for forming a treated reclaimed bottom ash sand and a treated reclaimed bottom ash sand. The method includes providing reclaimed bottom ash sand. The reclaimed bottom ash sand is contacted with an aqueous composition having 0.5 to 3.0 M NaOH for a time greater than about 4 hours. The NaOH contacted reclaimed bottom ash sand is rinsed and decanted and iron is removed to form a treated reclaimed bottom ash sand having reduced hydrogen formation in concrete compared to the hydrogen formation of concrete utilizing reclaimed bottom ash sand. The treated reclaimed bottom ash sand includes reactive aluminum of less than 50% by weight of the reactive aluminum in the reclaimed bottom ash sand and the treated reclaimed bottom ash sand includes less than 2 wt % iron. A concrete formed from the treated reclaimed bottom ash sand is also disclosed.

A method for forming a treated reclaimed bottom ash sand and a treated reclaimed bottom ash sand. The method includes providing reclaimed bottom ash sand. The reclaimed bottom ash sand is contacted with an aqueous composition having 0.5 to 3.0 M NaOH for a time greater than about 4 hours. The NaOH contacted reclaimed bottom ash sand is rinsed and decanted and iron is removed to form a treated reclaimed bottom ash sand having reduced hydrogen formation in concrete compared to the hydrogen formation of concrete utilizing reclaimed bottom ash sand. The treated reclaimed bottom ash sand includes reactive aluminum of less than 50% by weight of the reactive aluminum in the reclaimed bottom ash sand and the treated reclaimed bottom ash sand includes less than 2 wt % iron. A concrete formed from the treated reclaimed bottom ash sand is also disclosed.

A system and method for producing a modified coal ash involves collecting a bulk quantity of such coal ash, generally after it has been produced or landfilled, or is otherwise at temperatures closer to ambient, as opposed to power plant operational temperatures. In one possible implementation, the method herein involves removing carbon from the coal ash, such removal occurring by exposing the carbon to indirect heat, that is, externally-applied heat. For coal ashes with higher ash content. This removal is accomplished by subjecting the coal ash stream to heat, in one implementation, ranging between 850° F. and 1200° F., and such heat exposure occurring from about 10 minutes to about 30 minutes. The range of exposure time for the coal ash is determined so as to reduce the LOI from its initial level to a level acceptable for intended re-use or recycling. In one application, the LOI of carbon in the ash is reduced to 3% or less carbon. Upon completion of the range of the exposure time, the coal ash stream is removed from the sublimation heat, thereby forming a modified coal ash.

Methods of producing solid CO.sub.2 sequestering carbonate materials are provided. Aspects of the methods include introducing a divalent cation source into a flowing aqueous liquid (e.g., a bicarbonate rich product containing liquid) under conditions sufficient such that a non-slurry solid phase CO.sub.2 sequestering carbonate material is produced. Also provided are systems configured for carrying out the methods.

Methods of producing solid CO.sub.2 sequestering carbonate materials are provided. Aspects of the methods include introducing a divalent cation source into a flowing aqueous liquid (e.g., a bicarbonate rich product containing liquid) under conditions sufficient such that a non-slurry solid phase CO.sub.2 sequestering carbonate material is produced. Also provided are systems configured for carrying out the methods.

Manufacturing lightweight aggregate (LWA) by a sintering technique requires a delicate balance among three conditions: forming sufficient amount of molten liquid phase during sintering; reaching an appropriate viscosity for solid-liquid suspension; and emitting sufficient amount of gas that can be entrapped by the liquid phase to form pores. LWAs were made from low-calcium and high-calcium Waste Coal Combustion Ash (W-CCA) including fly ash and bottom ash. A mass fraction of at least 40% liquid phase for fly ash and 50% for bottom ash is required for a successful entrapment of emitted gaseous phases during sintering. Larger pores were observed in the microstructure of LWA samples made using high-calcium W-CCA in comparison to low-calcium W-CCA. This result was mainly attributed to the high-calcium samples forming liquid phases with lower viscosity values and emitting higher amounts of gaseous phase during sintering than did the low-calcium samples. The gaseous phase was generated by hematite reduction and anhydrite decomposition.

Manufacturing lightweight aggregate (LWA) by a sintering technique requires a delicate balance among three conditions: forming sufficient amount of molten liquid phase during sintering; reaching an appropriate viscosity for solid-liquid suspension; and emitting sufficient amount of gas that can be entrapped by the liquid phase to form pores. LWAs were made from low-calcium and high-calcium Waste Coal Combustion Ash (W-CCA) including fly ash and bottom ash. A mass fraction of at least 40% liquid phase for fly ash and 50% for bottom ash is required for a successful entrapment of emitted gaseous phases during sintering. Larger pores were observed in the microstructure of LWA samples made using high-calcium W-CCA in comparison to low-calcium W-CCA. This result was mainly attributed to the high-calcium samples forming liquid phases with lower viscosity values and emitting higher amounts of gaseous phase during sintering than did the low-calcium samples. The gaseous phase was generated by hematite reduction and anhydrite decomposition.

Roofing granules comprising agglomerated inorganic material, and building materials, such as shingles, that include such roofing granules. By fabricating roofing granules from agglomerating inorganic material it is possible to tailor the particle size distribution so as to provide optimal shingle surface coverage, thus reducing shingle weight and usage of raw materials. Additionally, the use of agglomeration permits the utilization of by-products from conventional granule production processes.

The present disclosure provides a cementitious material and production method thereof. The method comprises steps of: (1) dry desulfurization and denitrification of a flue gas with a flue gas absorbent to give a by-product, wherein the flue gas absorbent comprises 10-23 parts by weight of a nano-sized metal oxide, 10-23 parts by weight of a micro-sized metal oxide, and 40-60 parts by weight of magnesium oxide, the nano-sized metal oxide being selected from one or more of the group consisting of SiO2, CaO, Fe2O3, Al2O3, CuO, V2O5 and MnO2, and the micro-sized metal oxide being selected from one or more of the group consisting of SiO2, CaO, Fe2O3, Al2O3, CuO, V2O5 and MnO2; and (2) uniformly mixing the by-product with magnesium oxide, an industrial solid waste and an additive to give the cementitious material.

The present invention provides a method for reforming coal ash, including classifying coal ash having 10% by mass or more of a residue on a 45 μm sieve by using a forced vortex centrifugal type classifying apparatus, under a condition that the residue on a 45 μm sieve of the coal ash after the classifying becomes in a range of 1% by mass or more and 8% by mass or less.