Abstract: A process for separating 1,5-dinitroanthraquinone and 1,8-dinitroanthraquinone by heating a dinitroanthraquinone mixture, in a mixture of from 5 to 85 per cent by weight of N-methylpyrrolidone and from 95 to 15 per cent by weight of an organic liquid which boils at from 80.degree. to 210.degree. C and is miscible in all proportions with N-methylpyrrolidone, at from 60.degree. to 180.degree. C, and separating off the undissolved material, at the extraction temperature, after the solution equilibrium has been reached. The insoluble material contains more than 85 per cent by weight, and as a rule more than 90 per cent by weight, of 1,5-dinitroanthraquinone. From the extract, it is possible to isolate the dissolved 1,8-dinitroanthraquinone together with the dissolved 1,5-dinitroanthraquinone and any byproducts which may be present.

Abstract: To separate solid particles from liquids or gas, the liquid or the gas is passed through a coil, formed from one or more threads wound on a carrier. After subsequent washing and drying, the solid which has been filtered out during the filtration process is removed by unwinding the coil from the carrier, the latter consisting of a permeable hollow cylinder closed at both end faces by means of end plates, and provided with a feed orifice.

Abstract: A process for the production of milled particulate resins which comprises carrying out the reaction of the resin components in a moving reaction vessel containing carrier bodies. The new process is particularly suitable for the production of pigmented resins, for example daylight fluorescent pigments.