Abstract: A method for treatment of water works sludge. Water works sludge is a waste product that at present is returned to the recipient that the water works takes it water from. This cannot continue in the long run. The water works sludge must be taken care of. Significant for the method according to the invention is that the water works sludge is dried in a first step is dried, then the water works sludge is air-dried in a second step to a dry matter content of 30-80%. According to a preferred embodiment of the invention the dried water works sludge is further processed to an absorber, especially absorbers for oil or urine from cats, the dried water works sludge being crushed or subjected to further drying.

Abstract: An apparatus for producing expanded thermoplastic microspheres, including a belt conveyor (A) having an endless belt (1) for conveying microspheres. A device (B) for infrared (IR) heating, including a plurality of IR lamps (4) is located above the belt (1). A dosing device (C) for the dried unexpanded microspheres is located at one end of the belt conveyor and in conjunction with the belt (1). A collecting device (D) for expanded microspheres is located at the other end of the belt conveyor and in conjunction with the belt (1).

Abstract: The present invention relates to a method for producing expanded thermoplastic microspheres by heating. Unexpanded microspheres are dried under agitation to a dry solids content exceeding 98% by weight, preferably 99% by weight, before heating. The dried microspheres can be rewetted and then expanded by heating. The microspheres thus produced contain but minor amounts of agglomerates, The invention also comprises an apparatus for expanding the dried spheres. The apparatus has a belt conveyor (A), a device (B) for IR heating, a dosing device (C) for unexpanded spheres, and a collecting device (D) for expanded spheres.