Granulated activated carbon for water treatment
OwnerKen K. Robinsoninventor
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Abstract
A granulated activated carbon is produced by spherically agglomerating activated carbon powder in an aqueous slurry in the presence of a bridging liquid and a binder. At least about 50% of the carbon powder has a surface area of from about 2800 to about 3500 m.sup.2 /gm, an iodine number of from about 2500 to about 3500 mg/gm, a total pore volume of from about 1.0 to about 2.8 cc/gm, and a bulk density of from about 0.27 to about 0.32 gm/cc. The granules are activated by treatment with steam to provide granules having particle diameters of from about 0.17 to about 0.71 mm, and pore size distribution and adsorptive capacity essentially unchanged from that of the carbon powder. The granules are particularly effective for the treatment of drinking water to reduce the level of undesirable contaminants.
Claims9
A process of preparing a spherically-shaped, agglomerated granuled carbon composition from an activated carbon powder, the major portion of which is a carbon powder having a surface area of from about 2800 to about 3800 m.sup.2 /gm and exhibiting a trimodal pore volume distribution of peak volumes in the micropore size of <10 A.degree., the meso-pore size of from about 40 to about 200 A.degree., and a macro-pore side of >1000 A.degree., which process comprises the steps of:
- (a) mixing with agitation to form spherically-shaped granules an aqueous slurry of the carbon powder with from about 40 to about 60%, based on the weight of the carbon, of a hydrocarbon bridging liquid, and from about 5 to about 25%, based on the weight of the carbon, of a binder selected from the group consisting of clays and organic polymer adhesives;
- (b) separating and drying the granules;
- and
- (c) activating the granules by steam treatment at a temperature of about from 105.degree. to about 120.degree. C. to produce granules having particle diameters of from about 0.17 to about 0.71 mm.
A process for preparing a spherically-shaped, agglomerated granulated carbon composition from an activated carbon powder, the major portion of which is a carbon powder having a surface area of from about 2800 to about 3800 m.sup.2 /gm and exhibiting a trimodal pore volume distribution of peak volumes in the micropore size of <10 A.degree., the meso-pore size of from about 40 to about 200 A.degree., and the macro-pore size of >1000 A.degree., which process comprises the steps of:
- (a) mixing with agitation to form spherically-shaped granules an aqueous slurry of the carbon powder with from about 40 to about 60%, based on the weight of the carbon, of a hydrocarbon bridging liquid, and from about 5 to about 25%, based on the weight of the carbon, of a binder selected from the group consisting of kaolin, dolomite, and talc;
- (b) separating and drying the granules;
- and
- (c) activating the granules by steam treatment at a temperature of from about 105.degree. to about 120.degree. C. to produce granules having particle diameters of from about 0.17 to about 0.71 mm.
Dependencies are inferred from the claim text.