Hoechst Aktiengesellschaft

Joachim Stendel

Herbert Diskowski

Georg Strauss

Wilhelm Portz

Hans Ebert

Winfried Kern

Hans Rabowsky

Gunther Moormann

Bernhard Schafgen

Karl Rottgen

Heinrich Weiler

Horst Witt

The disclosure relates to a process for removing foreign components, especially zinc, from the product cycle during the production of yellow phosphorus inside and electrothermal furnace. To this end, the disclosure provides for molten ferrophosphorus and a calcium metasilicate slag and also a dust-containing gas mixture consisting essentially of carbon monoxide and phosphorus in vapor form to be taken from the furnace charged with phosphate pellets, coke and gravel. After electrostatic separation of the dust from the gas mixture, the dust is water-treated and made into a dust suspension. Crude phosphate is granulated on a granulating means using a mixture of dust suspension and binder which preferably is a clay suspension. The granulated material is calcined on a sintering device and made into phosphate pellets. A portion of the molten slag taken from the electrothermal furnace is allowed to solidify and the solidified slag is ground. The ground slag and at least a portion of dust suspension are granulated on a granulating means. The granulated slag and dust suspension are dried. It is possible for the dried granulated matter to be ground once again, to be granulated once again together with a further portion of dust suspension, and to be dried again. The dried and granulated matter is ultimately calcined and made into pellets.

Process for the electrothermal production of yellow phosphorus

The invention provides carbon carriers of improved reactivity suitable for use in slag-forming electrothermal reduction processes. The improved carbon carriers contain 5 to 80 weight % of the particular slag formed in the reduction process. The invention also provides a process for making the carbon carriers.

Carbon carrier suitable for use in electrothermal reduction processes,

Pellet-shaped calcium hydroxide forming part of the mixture of flux and ores in electrothermal calcium carbide furnaces is calcined. The pellets are made by granulating or briquetting moist calcium hydroxide, delivered to a sintering grate and conveyed thereon through a heating zone, wherein high temperatures are produced by the combustion of gas, above the grate, and wherein the combustion gas is exhausted, below the grate. The calcium hydroxide pellets are more especially placed on to the grate, covered with a layer of broken limestone and the undried pellets are directly conveyed through the heating zone, in an apparatus for carrying out the process.

Process for calcining pellet-shaped calcium hydroxide

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Bruhl, Germany

Joachim Stendel