C04B18/065

Methods for coal combustion product (CCP) recovery and related products

Methods of recovering coal combustion products (CCPs) and/or dry bottom furnace slag (DBFS) from coal combustion byproducts are disclosed. The methods include compiling coal combustion byproducts (e.g., from combustion of lignite coal and/or bituminous coal), grinding the coal combustion byproducts to form ground coal combustion byproducts with a maximum particle size of 40 microns, and separating CCPs from the ground coal combustion byproducts using an electrostatic precipitator. The following CCPs can be separated from the coal combustion byproducts using the presently disclosed methods: fly ash, bottom ash (e.g., containing pyrites), scrubber materials (e.g., calcium sulfate and calcium sulfite), and raw coal.

Methods for coal combustion product (CCP) recovery and related products

Methods of recovering coal combustion products (CCPs) and/or dry bottom furnace slag (DBFS) from coal combustion byproducts are disclosed. The methods include compiling coal combustion byproducts (e.g., from combustion of lignite coal and/or bituminous coal), grinding the coal combustion byproducts to form ground coal combustion byproducts with a maximum particle size of 40 microns, and separating CCPs from the ground coal combustion byproducts using an electrostatic precipitator. The following CCPs can be separated from the coal combustion byproducts using the presently disclosed methods: fly ash, bottom ash (e.g., containing pyrites), scrubber materials (e.g., calcium sulfate and calcium sulfite), and raw coal.

Reducing mercury emissions from the burning of coal
09822973 · 2017-11-21 · ·

Sorbent components containing halogen, calcium, alumina, and silica are used in combination during coal combustion to produce environmental benefits. Sorbents such as calcium bromide are added to the coal ahead of combustion and other components are added into the flame or downstream of the flame, preferably at minimum temperatures to assure complete formation of the refractory structures that result in various advantages of the methods. When used together, the components reduce emissions of elemental and oxidized mercury; increase the level of Hg, As, Pb, and/or Cl in the coal ash; decrease the levels of leachable heavy metals (such as Hg) in the ash, preferably to levels below the detectable limits; and make a highly cementitious ash product.

Reducing mercury emissions from the burning of coal
09822973 · 2017-11-21 · ·

Sorbent components containing halogen, calcium, alumina, and silica are used in combination during coal combustion to produce environmental benefits. Sorbents such as calcium bromide are added to the coal ahead of combustion and other components are added into the flame or downstream of the flame, preferably at minimum temperatures to assure complete formation of the refractory structures that result in various advantages of the methods. When used together, the components reduce emissions of elemental and oxidized mercury; increase the level of Hg, As, Pb, and/or Cl in the coal ash; decrease the levels of leachable heavy metals (such as Hg) in the ash, preferably to levels below the detectable limits; and make a highly cementitious ash product.

Methods of utilizing coal combustion residuals and structures constructed using such coal combustion residuals

A process of fabricating a static structure including an interior volume that includes the steps of mixing coal combustible residual (CCR) with structural reinforcing materials to form a construction material and utilizing the construction material to fabricate exterior enclosure-forming components of the static structure. The enclosure-forming components are sufficiently reinforced, enhanced and/or thick to provide protection against exterior forces directed against the structure.

Method of Lightweight Aggregates Production from Waste-Coal Combustion Ash

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.

Method of Lightweight Aggregates Production from Waste-Coal Combustion Ash

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.

Coal ash treatment system and method

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.

Method of lightweight aggregates production from waste-coal combustion ash

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.

Method of lightweight aggregates production from waste-coal combustion ash

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.