Abstract: An activated carbon fiber spun yarn having excellent workability and adsorptive property is disclosed. The activated carbon fiber spun yarn comprising activated carbon fibers having a specific surface area of 500 to 1,500 m.sup.2 /g, a ductility of at least 0.5%, and a tensile strength of at least 10 kg/mm.sup.2 and derived from acrylonitrile-based fibers. The spun yarn has a twist coefficient of 30 to 60.

Abstract: Fibrous activated carbon having a pH not more than 5 which is suitable for recovering halogenated hydrocarbon solvents is disclosed. The fibrous activated carbon is obtained by acid treating raw fibrous activated carbon.

Abstract: A method for manufacturing activated carbon fibers is disclosed. The method is comprised of the steps of:(1) causing an acrylic fiber to contain therein a treating agent selected from the group consisting of phosphorus and boron compounds in a concentration of 0.01 to 0.3% by weight as phosphorus or boron based on the weight of the fiber;(2) preoxidizing the acrylic fiber in an oxidizing atmosphere at a temperature exceeding 200.degree. C. and giving a core ratio of 18% until the amount of bonded oxygen becomes not less than 15% by weight based on the weight of the fiber thereby producing a preoxidized fiber;(3) adjusting the concentration of the treating agent in the preoxidized fiber to a level in the range of 0.04 to 1% by weight based on the thus obtained preoxidized fiber; and(4) thereafter activating the fiber at a temperature in the range of 900.degree. to 1,300.degree. C. The resulting fiber has improved high strength, high adsorbing ability and high processibility.