摘要:
A method for feeding lime mud into a lime kiln including a rotary kiln shell having an interior between a first end wall and a second end wall, the method including: feeding the lime mud into a flue gas flow in the interior of the rotary kiln shell or in close proximity to the shell to pretreat the lime mud; separating the pretreated lime mud from the flue gas flow; conveying the separated lime mud into the lime kiln, and calcining the separated lime mud in the lime kiln.
摘要:
A method for treating cement kiln dust containing alkaline metal salts includes the steps of hydration (formation of calcium hydroxide), dehydration i.e. drying, fractionation by sieving and carbonation (reaction of the fractionated moistened cement kiln dust) with CO2 gas in a fluidized bed reactor.
摘要:
An environmental friendly process for the production of precipitated calcium carbonate suitable for industrial application from calcium carbonate rich by-product of nitrophosphate fertilizer plant by adopting purification steps of calcination, carbonation and optional treatment with emulsion of fatty acid or its derivatives.
摘要:
This invention describes the use of a fluidized bed reactor in the carbonation of a solid, inorganic and alkaline particulate material which contains alkaline metal salts. It also describes a method for treating cement kiln dust (CKD) containing alkaline metal salts. The treatment method comprises two steps: (a) a hydration step; and (b) a carbonation step, wherein the carbonation step is carried out in a fluidized bed reactor. In a preferred aspect of the present invention, the treated CKD is used as an aggregate in sulfur polymer concrete (SPC). Accordingly, the present invention also provides a method for producing SPC, which method comprises heating and mixing treated CKD of the present invention, elemental sulfur and modified sulfur to produce a mixture. The SPC can be used as a barrier to restrict permeation of matter, e.g. in a containment construction for storing matter such as hazardous waste.
摘要:
Methods and systems are provided for producing a carbonate precipitation material comprising stable or reactive vaterite from carbide lime that provides both a source of divalent cations (Ca2+ ions, Mg2+ ions, etc.) and a source of proton removing agent.
摘要:
This invention describes the use of a fluidized bed reactor in the carbonation of a solid, inorganic and alkaline particulate material which contains alkaline metal salts. It also describes a method for treating cement kiln dust (CKD) containing alkaline metal salts. The treatment method comprises two steps: (a) a hydration step; and (b) a carbonation step, wherein the carbonation step is carried out in a fluidized bed reactor. In a preferred aspect of the present invention, the treated CKD is used as an aggregate in sulfur polymer concrete (SPC). Accordingly, the present invention also provides a method for producing SPC, which method comprises heating and mixing treated CKD of the present invention, elemental sulfur and modified sulfur to produce a mixture. The SPC can be used as a barrier to restrict permeation of matter, e.g. in a containment construction for storing matter such as hazardous waste.
摘要:
The invention features methods and systems for producing commercial quality carbon dioxide (CO2) of 90% to +99% purity using, wet calcium carbonate lime mud produced in a manufacturing operation, for instance, Kraft pulp mill lime mud (a.k.a., “lime mud”) as a feedstock to a multi-stage lime mud calcination process. This process may be fueled with waste water treatment plant (WWTP), sludge biomass, precipitated lignins, coal, or other low cost solid fuels. High reactivity “soft-burned” lime product (“calcine”) required in the mill's chemical recovery circuit is also produced, and steam and heated boiler feed-water is generated and exported to the mill's steam distribution and generation system as well as hot process water for use in the mill's boiler house and manufacturing operation. The system for calcining calcium carbonate lime mud produced from a re-causticizing manufacturing operation and converting it to re-burned lime and CO2 comprises a calciner and a combustor linked by a moving media heat transfer (MMHT) system or apparatus. The MMHT system or apparatus thermally links separate fluid bed combustion (exothermic) and calcination (endothermic) stages with a solid particulate media. The system further comprises a flash dryer or spray dryer that utilizes exhausted heat from the calcination stage.
摘要:
An environmentally friendly process for the production of precipitated calcium carbonate suitable for industrial application from a calcium carbonate-rich by-product of a nitrophosphate fertilizer plant. The process employs purification steps of calcination, carbonation and optional treatment with an emulsion of fatty acid or fatty acid derivatives.
摘要:
The instant disclosure sets forth a process for re-activating a mineral residue. The process includes providing a mineral residue, which includes a core and a shell around the core. In certain examples, the core comprises calcium (Ca), magnesium (Mg), or a combination thereof. The Ca and Mg is not present as elemental Ca or Mg but rather as a compound of Ca or of Mg, such as but not limited to Ca(OH)2 or Mg(OH)2. In certain examples, the shell comprises an oxide, a hydroxide, a carbonate, a silicate, a sulfite, a sulfate, a chloride, a nitrate, or nitrite, of calcium (Ca) or of magnesium (Mg), or a combination thereof. The process includes (a) fractionating the mineral residue; (b) contacting the mineral residue with an acid and fractionating the mineral residue; or (c) contacting the mineral residue with a base and fractionating the mineral residue. As a result, the mineral residue's core is exposed. In some examples, the shell is passivating and inhibits the Ca or Mg, or both, in the core from reacting with carbon dioxide (CO2). By exposing the core as described herein, a mineral residue's reactivity with carbon dioxide is increased.
摘要:
The invention features methods and systems for producing commercial quality carbon dioxide (CO2) of 90% to +99% purity using, wet calcium carbonate lime mud produced in a manufacturing operation, for instance, Kraft pulp mill lime mud (a.k.a., “lime mud”) as a feedstock to a multi-stage lime mud calcination process. This process may be fueled with waste water treatment plant (WWTP), sludge biomass, precipitated lignins, coal, or other low cost solid fuels. High reactivity “soft-burned” lime product (“calcine”) required in the mill's chemical recovery circuit is also produced, and steam and heated boiler feed-water is generated and exported to the mill's steam distribution and generation system as well as hot process water for use in the mill's boiler house and manufacturing operation. The system for calcining calcium carbonate lime mud produced from a re-causticizing manufacturing operation and converting it to re-burned lime and CO2 comprises a calciner and a combustor linked by a moving media heat transfer (MMHT) system or apparatus. The MMHT system or apparatus thermally links separate fluid bed combustion (exothermic) and calcination (endothermic) stages with a solid particulate media. The system further comprises a flash dryer or spray dryer that utilizes exhausted heat from the calcination stage.