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US 8,721,785 B2Granted
Method for treating particulate material
AssigneeUnited Arab Emirates University
InventorsAbdel-Mohsen Onsy Mohamed, Maisa Mabrouk El Gamal
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AssigneeUnited Arab Emirates University
InventorsAbdel-Mohsen Onsy Mohamed, Maisa Mabrouk El Gamal
Estimating the term…
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.
A method for the carbonation of a solid, inorganic and alkaline particulate material which contains alkaline metal salts, which method uses a fluidized bed reactor to effect the carbonation, wherein the material is hydrated cement kiln dust (CKD) having a moisture content of 20% by weight or less.
A method for treating CKD containing alkaline metal salts, which method comprises (1) a hydration step, (2) a drying step and (3) a carbonation step, wherein the carbonation step is carried out in a fluidized bed reactor, and wherein if the hydrated CKD resulting from step (2) comprises particles greater than 10 mm in size at their widest point the method further comprises a fractionating step between steps (2) and (3), which fractionating step involves removing particles greater than 10 mm in size at their widest point.
Treated CKD which leaches less than 200 mg/l SO42−, less than 800 mg/l Cl−, less than 15 mg/l Cr, less than 1 mg/l Sr, less than 300 mg/l Ca, less than 1000 mg/l K and/or less than 150 mg/l Na, when tested according to the British Standard BS EN12457:
Dependencies are inferred from the claim text.