Abstract: A method of asbestos treatment in which an asbestos-containing waste material of arbitrary configuration can be detoxified completely and safely. The method of asbestos treatment comprises impregnating an asbestos-containing waste material with an acid so as to cause at least the asbestos at the surface of the waste material to be nonasbestous and further treating the treatment product in a cement production plant. In particular, the treatment in a cement production plant is a fusion treatment by means of a cement kiln. Therefore, not only can the asbestos-containing waste material be detoxified completely and safely but also a cement reusing the waste material can be produced.

Abstract: A method of asbestos detoxification in which an asbestos-containing waste material in any form is made harmless while preventing asbestos particles or dust from flying or scattering. The asbestos content can be easily reduced in a short time to 0.1 wt. % or lower, which is prescribed by the Ministry of Health, Labor, and Welfare. The waste can be perfectly made harmless. Also provided is an aqueous solution for asbestos detoxification which is for use in the method.

Abstract: An object of the present invention is to manufacture a material for concrete by using a fresh concrete sludge as a starting material. The invention relates to a method of manufacturing a material for concrete in which a material for concrete is manufactured from a slurry composed of a fresh concrete sludge obtained by treating a fresh concrete waste to separate a coarse aggregate and a fine aggregate. The manufacturing method comprises a grinding step of obtaining a product containing fine particles with a mean particle size of 10 ?m or less by wet grinding the slurry under a condition of water content of 60 wt. % or more.

Abstract: The invention provides an exhaust gas treatment agent characterized in that it comprises calcium silicate hydrate particles having a mean particle diameter of 0.2 to 4 &mgr;m and a specific surface area of not less than 60 m2/g and calcium hydroxide particles having a mean particle diameter of not more than 4 &mgr;m and the content of calcium hydroxide particles in both particle components is within the range of 20 to 60% by weight; a method of producing the exhaust gas treatment agent; and a process for the treatment of exhaust gases and soot and dust which uses the exhaust gas treatment agent.