Abstract: Granular activated carbon is manufactured from sub-bituminous coal by crushing and screening the as received coal containing about 10 to about 25% moisture by weight to produce 8/30 mesh granules, treating the granules with a dilute aqueous solution of inorganic acid at a concentration from about 1 to about 25% by weight to reduce the volatile content and thereby increase the fixed carbon content, the particular concentration being selected to provide the desired activity and porosity of the activated carbon, comprising: mixing the granules with the acid, washing off the acid, and drying the granules at least partially to a moisture content below about 25% by weight. The granules are mixed with from 0 to about 15% by weight of coal tar pitch.

Abstract: Granular activated carbon is manufactured from briquettes of about 1".times.2", formed from brown coal, from which iron material has been extracted and which has a moisture content of about 15% by weight, by crushing and screening the pretreated coal briquettes to produce 8/30 mesh granules, treating the granules with a dilute aqueous solution of inorganic acid (H.sub.2 SO.sub.4, H.sub.3 PO.sub.4 or HCl) at a concentration of about 1 to about 10% by weight to reduce the volatile content and thereby increase the fixed carbon content comprising: mixing the granules with the acid, washing off the acid, and drying the granules at least partially to a moisture content below about 25% by weight. In one case the washed granules are dried partially to a moisture content of about 10 to about 25% by weight without the addition of a carbonaceous binder such as coal tar pitch. In the other case the granules are dried thoroughly and mixed with about 5 to about 15% by weight of coal tar pitch.

Abstract: Granular activated carbon is manufactured from briquettes of about 1.times. 2" mesh formed from brown coal from which iron material has been extracted and which has a moisture content of about 15% by weight, by crushing and screening the pre-treated coal briquettes to produce 8/30 mesh granules, which are treated by mixing with about 5% by weight of concentrated inorganic acid (H.sub.2 SO.sub.4, H.sub.3 PO.sub.4, or HCl), without the addition of a carbonaceous binder such as coal tar pitch. The so treated granules are ground to form fine powder of more than about 65% by weight -325 mesh powder, more preferably 75 to 85% by weight -325 mesh, which powder has a moisture (including acid) content of about 21% by weight, as a temporary binder, and which powder is compressed into shapes such as pellets of 0.5" diameter and 0.5" long under a pressure of 40,000 to 80,000 psi, and then granulated to obtain 6/20 mesh granules.

Abstract: Granular activated carbon is manufactured from sub-bituminous coal by crushing and screening the as received coal containing about 10 to about 25% moisture by weight to produce 8/30 mesh granules, treating the granules with a dilute aqueous solution of inorganic acid at a concentration from about 1 to about 25% by weight to reduce the volatile content and thereby increase the fixed carbon content, the particular concentration being selected to provide the desired activity and porosity of the activated carbon, comprising: mixing the granules with the acid, washing off the acid, and drying the granules at least partially to a moisture content below about 25% by weight. The granules are mixed with from 0 to about 15% by weight of coal tar pitch.

Abstract: Granular activated carbon is manufactured from low rank agglomerating but not good coking bituminous coal by crushing and screening the as received coal to produce 8/30 mesh granules, which are treated with a dilute aqueous solution of inorganic acid to prevent fusion of the granules during subsequent devolatilization comprising: mixing the granules with the acid (H.sub.2 SO.sub.4, H.sub.3 PO.sub.4, HCl or mixtures thereof) at a concentration of about 1% to about 15% by weight, washing off the acid, drying the granules thoroughly and thereafter mixing the granules with about 5 to about 15% by weight of a carbonaceous binder such as coal tar pitch. The so treated granules are ground to at least about 65% by weight -325 mesh powder, which is compressed into shapes such as pellets of 0.5 inch diameter and 0.5 inch long under a pressure of 40,000 to 80,000 psi, and then granulated to obtain 6/20 mesh granules. These granules are first charred by heating to 250.degree. C at 150.degree.

Abstract: Granular activated carbon is manufactured from sub-bituminous coal by crushing and screening the as received coal containing 17% moisture by weight to produce 8/30 mesh granules which are treated by mixing with about 5% by weight of concentrated inorganic acid (H.sub.2 SO.sub.4, H.sub.3 PO.sub.4 or HCl), without the addition of a carbonaceous binder. The so treated granules are ground to more than 65% by weight -325 mesh powder, preferably 75 to 85% by weight -325 mesh, which powder has a moisture (including acid) content of about 21% by weight, as a temporary binder, and which powder is compressed into pellets of 0.5 inch diameter and 0.5 inch long under a pressure of 40,000 to 80,000 psi, and then granulated to obtain 6/20 mesh granules. These granules are devolatilized by heating to 450.degree. C at 300.degree. C/hour in an atmosphere of N.sub.2 and the volatiles and by maintaining the temperature for 1 hour, and then activated by heating to 800.degree. to 900.degree. C in an atmosphere of N.sub.