Abstract: New glass fibers having an average length of about 100 to 400 &mgr;m and an apparent density of about 1 to 0.2 g/cm3 are produced by spinning glass fibers, comprising spinning glass fibers into bundles, cooling with liquid to form wet bundles, directly cutting such bundles in the wet state, without previous drying, grinding said bundles to milled glass fibers in a high-efficiency mixer with the addition of a liquid, and then drying. The fibers are especially suited for filling polyurethanes by the PUR-RIM process.

Abstract: Preparation of a raw mix for use in the production of cement and sulphuric acid by the cement-sulphuric acid process, wherein coke is comminuted to a degree that at most 10% by weight of the coke has a particle size of less than 0.1 mm and at least 90% by weight has a particle size of less than 20 mm, but at least 60% by weight has a particle size greater than 0.2 mm, after which the thus comminuted coke is mixed with a mixture, of fine particle size, comprising calcium sulphate and the remaining additives.

Abstract: A pasty composition for the room temperature crosslinking and curing of a vulcanizable organopolysiloxane, comprising a crosslinking agent for an organopolysiloxane, a curing catalyst therefor, and about 3-40% by weight of the total amount of the pasty composition of active hydrophilic silica as a thickener. The pasty composition may additionally contain up to about 40% by weight of at least one inactive filler. Advantageously, the organopolysiloxane is in one tube and the pasty composition is in another; lengths of material are squeezed out in easily ascertained proportions and are mixed in the presence of water, e.g. water vapor in the atmosphere, the mixture setting to a silicone rubber.

Abstract: A process for purifying waste gypsum from the wet phosphoric acid process to a maximum fluorine content of 0.25 % by weight based on the anhydride, which comprises adding active silicic acid in two portions during the course of the phosphoric acid process, wherein at least half the total amount of silicic acid added is added during the decomposition of the crude phosphate and the remainder is added after the end of the decomposition but before the waste gypsum is filtered off, and the waste gypsum, after it has been filtered, is made into a suspension with water, separated from the liquid phase and dried.