Abstract: Highly fluorinated carboxylic acids can be removed from exhaust gas streams by scrubbing with concentrated alkali solutions if these alkali solutions have a density high enough for the salt of the highly fluorinated carboxylic acid to separate out as an independent phase. An apparatus suitable therefor contains a scrubber and a separation vessel which is advantageously equipped with a conveying element, a collection vessel connected via an overflow and a circulation line for the scrubbing liquor.

Abstract: By means of a 3,3'-dichlorobenzidine dihydrochloride suspension in hydrochloric acid, comprising the componentsa) 35 to 63.5% by weight of 3,3'-dichlorobenzidine dihydrochloride;b) 11 to 24% by weight of hydrogen chloride;c) and 25 to 55% by weight of-water, in each case relative to the total weight of the suspension (100% by weight) and with the proviso that the components a), b) and c) together make 100% by weight;and whose viscosity is in the range from 80 to 1400 mPa.s,3,3'-dichlorobenzidine dihydrochloride can be stably suspended in hydrochloric acid at high concentration and consequently low water content and at the same time a suspension having low viscosity can be obtained, so that the slurry flows out of containers without problems even after relatively long static storage.

Abstract: A fine-grained polyether-ketone powder, having a particle size with a d.sub.50 value smaller than or equal to 40 .mu.m and a grain size distribution range smaller than or equal to 55 .mu.m, is obtained by cold-grinding of coarse-grained polyether-ketone in a fluid-bed opposed-jets mill, which is provided with a grinding chamber (2) subjected to gas jets, a grinding material-charging device, a screening device (5) for separating coarse material (11) and fine material (10), and a bottom (3) underneath the grinding chamber for added material to be ground and coarse material flowing back from the screening device, the material to be ground and the coarse material flowing back from the screening device being cooled by means of a cryogenic refrigerant.The powders obtained in this way are used for producing surface coatings or composites.

Abstract: In a vibrating stirred ball mill, a stirred ball mill is mounted on a bearing which is provided with an eccentric drive. The stirrer is connected to the stirrer drive via an articulated shaft.

Abstract: Fluidized-bed counter-jet mills are gas-jet mills with which extremely fine milling results can be produced with very little wear and tear. An improvement in the milling results can be achieved by cooling the gas jets with a refrigerant, but the improvement that can be achieved is not substantial and the consumption of refrigerant is very high. In order to lower the consumption of refrigerant while considerably improving the fineness of the milled material, the coarse material which is separated by the grader of the mill is cooled by the refrigerant within the fluidized-bed counter-jet mill and fed back into the milling chamber. Liquid nitrogen is the preferred refrigerant with which the sump of the mill is cooled.

Abstract: Metal ions are reduced from a higher to a lower oxidation stage using ferrophosphorus as the reductant.

Abstract: The invention relates to a process for preparing compositions for coating metal substrates or work pieces in an aqueous bath, in which the substrate forms the cathode.In this process 5-35% by weight of at least one epoxy resin, 2-20% by weight of at least one ketone and/or hydrocarbon resin, 15-60% by weight of at least one cationic synthetic resin having functional groups--this compound is a 10-50% by weight dispersion or solution--, 5-30% by weight of at least one organic cross-linking agent, which is solid at ambient temperature and 0-73% by weight of pigments and/or conventional adjuvants are processed together in one or more stages in a grinding apparatus to form a homogeneous coating composition. At least one stage being a wet operation. The composition has a particle size of less than 100 .mu.m, preferably less than 15 .mu.m. The grinding bath is adjusted with water to the solids content required for application.

Abstract: The invention provides a process for the manufacture of a polyethylene wax micro-powder, 99 weight % of which has a grain size of less than 15 microns, for the dulling of varnishes. Such a micro-powder generally cannot be obtained without difficulty by grinding; in accordance with the invention this is possible, however, by grinding the polyethylene wax together with an amide wax.

Abstract: A method of reducing the particle size of cellulose compounds selected from the group consisting of cellulose and ether derivatives thereof which comprises grinding said compounds in a vibration mill in the presence of air and in the presence of sufficient water to yield a product having a water content of from 2 to 10% by weight, wherein at least 50% of the particles in the product have a particle size of 100 .mu. or less, a product obtained by said method and a binder composition containing said product.

Abstract: A continuous process for preparing copper phthalocyanines by caking a mixture of phthalodinitrile, and a copper salt which comprises carrying out the reaction in a continuously working, heatable, tubular vibration mill, which contains iron or steel bars in the grinding room.In comparison with the continuous processes hitherto known this process requires a considerably smaller amount of thermal energy from outside, since the amount of heat formed in the strongly exothermic condensation process is, to a considerable extent conducted away from the reaction zone, with the aid of heat-conducting grinding bars, and is used in order to heat up the freshly introduced starting product to room temperature.