GB1355674A - Production of regeneratable active carbons - Google Patents

Abstract

1355674 Active carbon; water purification DEUTSCHE GOLDUND SILBER-SCHEIDEANSTALT 2 July 1971 [4 July 1970] 31039/71 Headings C1A and C1C A regeneratable active carbon suitable for water purification comprises carbon grains having an inner surface area of more than 1000 m.<SP>2</SP>/g., iodine adsorption numbers of more than 1000 mg./g. of carbon, an adsorption capacity with respect to tetrapropylene benzene sulphonate of at least 12% by weight, a total pore volume of at least 1À20 ml./g. of carbon and a fatigue factor i.e. reduction in adsorption capacity in the dechlorination of drinking water of less than 1À5. The carbon is made by forming a paste of powdered carbon with wood tar and as catalyst an alkali compound in an amount of from 12 to 20% by weight of the wood tar and carbon mix, compacting the mix under an absolute pressure of from 20 to 150 kp./cm.<SP>2</SP>, size reducing and sifting the compact mixture, low-temperature carbonizing the mixture, e.g. at 400-450‹ C. and activating the carbonized product, e.g. with steam. The catalyst may be KOH and/or K 2 CD 3 . Specified carbons are charcoal, carbon black, mineral coal, lignite, peat, coke and petroleum coke. The carbon product may include non-carbon materials such as magnesium, aluminium, chromium, silver or manganese oxides, copper carbonate, silicas and kieselguhr. These optional additives function as flocculating, germ removing, filtration and deodorizing aids. Drinking water, free from colour and odour, are obtained by passing water, aqueous solutions and suspensions through a layer of the above active carbon.