GB1504819A - Method for making activated carbon - Google Patents

Abstract

1504819 Activated carbon AMERICAN MINECHEM CORP 2 July 1976 [3 July 1975] 27724/76 Heading C1A [Also in Division C5] Activated carbon is made by (a) dispersing carbonaceous and non-carbonaceous fine particles in a suspension liquid to form a slurry; (b) adding to the slurry a liquid lyophobic to the suspension liquid and the non-carbonaceous fine particles and lyophilic to the carbonaceous fine particles to form a mixture; (c) agitating the mixture to preferentially agglomerate said carbonaceous fine particles while the non-carbonaceous fine particles remain substantially unagglomerated in the mixture; (d) separating the agglomerated carbonaceous fine particles from the mixture; (e) carbonizing the separated agglomerated carbonaceous material and (f) activating the separated agglomerated carbonaceous material to form activated carbon. Preferably, the starting material is crushed non- coking anthracite or bituminous coal, in which the carbonaceous particles are coal and the non- carbonaceous fine particles are ash, but in addition lignite, carbon black and coke-oven and wood pitches may be used. Water is the preferred suspension liquid and the agglomerating liquid may be a hydrocarbon, especially light oil, light or heavy fuel oil, or kerosene. Separation may be effected by screening, elutriation or using a cyclone or spiral separator. Carbonization and activation may be effected at least partially concurrently by gas activation, preferably by heating the agglomerated carbonaceous fine particles to at least 450‹ C., desirably at least 500‹ C., in the presence of steam. Typically the carbon product has a carbon content of about 96% and an internal surface area of about 3500 sq. ft./gm. In a modification, after separating the agglomerated carbonaceous fine particles and prior to carbonizing and activating, a carbonizable binder liquid is added to the agglomerate to form a second mixture which is agitated to pelletize the agglomerated carbonaceous fine particles. Suitable binder liquid includes heavy hydrocarbons such as coke-oven coal tar, oil shale crude, petroleum crude and heavy fuel oil.