Abstract: A desiccant comprising crystalline, anhydrated nystose, which contains 70% or more of nystose and 2% or less of moisture and is in the form of a crystalline powder, is capable of maintaining water activity of a food at an extremely low level without heat drying the food or drying the food with silica gel or the like and can safely prevent deteriorations of foods and maintain the qualities at a low cost. The desiccant can be produced by anhydrating crystalline nystose hydrate under reduced pressure or in the presence of a dehydrating agent. The desiccant is used for lowering water activity of a food and maintaining the same, by directly contacting the desiccant with the food or mixing the same with the food.

Abstract: A high-concentration coal-water slurry of a coal concentration as high as 71 percent by weight at a viscosity of 2,000 cp (at 25.degree. C.) can be produced by first coarsely crushing a starting coal, further pulverizing 95 to 30 percent by weight of the coarsely crushed thus obtained, subjecting the finely pulverized coal thus obtained, together with the remainder of the coarsely crushed coal, to crushing in a wet-type crusher, and pulverizing and adjusting the coal particles to a particle size constitution of 20 to 30 percent by weight of 200-mesh size and larger and 80 percent by weight or less of 350-mesh size and smaller.

Abstract: A method of recovering fuel from coal ash containing non-combusted carbon in particulate form discharged from a pulverized coal fired boiler, a fluidized bed boiler or a coal gasification furnace together with exhaust gases. In this method, water and a binder and surfactant, if necessary, are added to the ash collected by the dust collecting device, and the mixture is agitated to form coarse particles of high carbon content. Then fine particles of high ash content are separated from the coarse particles, allowing the coarse particles separated from the fine particles to be dehydrated while tailing ash is turned white in color and the ash is put to use.

Abstract: High concentrated coal-water slurry is produced by coarsely crushing coal, thereafter pulverizing the coarsely crushed coal, together with water and a slurry dispersant, according to necessity, in a wet-type ball mill, and feeding back one portion of the finely pulverized coal slurry thus obtained into the inlet of the wet-type ball mill.

Abstract: Waste synthetic high polymer, especially those containing polyvinyl chloride and the like chlorine-containing synthetic resins are heated at 200.degree.-500.degree.C to thereby form a hot molten bath of fusible materials contained in the waste resin mixture and the chlorine-containing resins are effectively decomposed in the molten bath kept at the temperature of 200.degree.-500.degree.C with the generation of hydrogen chloride gas which can be recovered as hydrochloric acid.

Abstract: Waste synthetic high polymer, especially those containing polyvinyl chloride and the like chlorine-containing synthetic resins are heated at 200.degree.-500.degree.C to thereby form a hot molten bath of fusible materials contained in the waste resin mixture and the chlorine-containing resins are effectively decomposed in the molten bath kept at the temperature of 200.degree.-500.degree.C with the generation of hydrogen chloride gas which can be recovered as hydrochloric acid.