Hoechst Aktiengesellschaft

Ursus Thummler

Hugo Werner

Horst Staendeke

Gero Heymer

Hans-Werner Stephan

Bernhard Kuxdorf

Klaus Lehr

Peter Luhr

Franz-Josef Dany

Joachim Kandler

Joachim Wortmann

Wilhelm Adam

Jurgen Svara

Friedrich-Wilhelm Dorn

Harry Sander

Walter Klemm

In a stabilized, pulverulent red phosphorus comprising phosphorus particles having a maximum particle size of 2 mm whose surface is covered with a thin layer of an oxidation stabilizer, the oxidation stabilizer is composed of tin oxide hydrate.

Stabilized red phosphorus

For removing hydrogen phosphide from waste air, the hydrogen phosphide-containing waste air is passed at temperatures from 50.degree. to 350.degree. C. over a catalyst which is composed, at least on its surface, of at least one metal which, in a 1-molar acidic aqueous solution, has a potential which is at least 200 mV more positive than that of the standard hydrogen electrode.

Process for removing hydrogen phosphide from waste air

Stabilized pulverulent red phosphorus consisting substantially of particles with a size of at most 2 mm, encapsulated in a thin layer of an oxidation stabilizer consisting of at least one scarcely water-soluble or water-insoluble metal hydroxide and a melamine/formaldehyde-polycondensation product.

Stabilized red phosphorus and process for making it

The disclosure relates to a process for making phosphorus pentoxide by subjecting elemental yellow phosphorus to combustion with dried air inside a steel-made combustion chamber with utilization of the reaction heat for the production of energy. To this end, the disclosure provides for the combustion to be effected inside a combustion chamber of which the walls are arranged so as to form a cooling system with cavities therein; for water or a water/steam-mixture as a heat carrier abstracting the reaction heat to be circulated through the cooling system, the water or water/steam-mixture assuming an increased temperature being circulated, preferably under increased pressure; for steam formed in the cooling system to be continuously taken therefrom; for an equivalent proportion of fresh desalted water to be introduced into the cooling system; for hot gaseous phosphorus pentoxide issuing from the combustion chamber to be condensed or worked up into phosphoric acid; for the steam taken from the cooling system to be passed through a steam delivery pipe disposed in the upper portion of the combustion chamber, or through a delivery conduit for product gas containing phosphorus pentoxide; for the steam to be heated therein to a temperature of 400.degree. to 600.degree. C. under constant pressure, and for the steam so superheated to be used.

Process for making phosphorus pentoxide and optionally phosphoric acid

The disclosure relates to a process for making phosphorus pentoxide by subjecting elemental yellow phosphorus to combustion with dried air inside a steel-made combustion chamber with utilization of the reaction heat for the production of energy. To this end, the disclosure provides for the combustion to be effected inside a combustion chamber of which the walls are arranged so as to form a cooling system with cavities therein; for a liquid or liquid/steam-mixture as a heat carrier abstracting the reaction heat to be circulated through the cooling system, the liquid or liquid/steam-mixture assuming an increased temperature being preferably so circulated under increased pressure; for steam formed in the cooling system to be continuously taken therefrom; for an equivalent proportion of fresh liquid to be introduced into the cooling system; for hot P.sub.2 O.sub.5 issuing in vapor form from the combustion chamber to be condensed or worked up into desirable final product, the combustion chamber being a cylindrical vessel with a height/diameter-ratio of 2.5:1 to 5:1 and having 1 to 10 burners disposed axisymmetrically in its circular base plate. The disclosure also relates to an apparatus for carrying out the process.

Process and apparatus for making phosphorus pentoxide with utilization

The invention relates to an apparatus for making red phosphorus by subjecting molten yellow phosphorus to a thermal conversion reaction in a closed reaction zone. To this end, a hollow shaft-provided and closed ball mill is preheated to a reaction temperature within the range 280.degree. to 590.degree. C. Yellow phosphorus is continuously introduced into the ball mill through the hollow shaft in quantities per unit time which permit the reaction temperature prevailing inside the ball mill to be maintained without supply of heat from the outside. More particularly, decreasing quantities of yellow phosphorous are introduced per unit time at increasing temperature and increasing quantities of yellow phosphorus are introduced per unit time at decreasing temperature within the limits specified. Red phosphorus is allowed to cool inside the ball mill, water is poured over it and the whole is subjected to wet-grinding. An aqueous suspension of red phosphorus is finally removed from the ball mill.

Apparatus for making red phosphorus

The invention relates to a process for making red phosphorus by subjecting molten yellow phosphorus to a thermal conversion reaction in a closed reaction zone. To this end, a hollow shaft-provided and closed ball mill is preheated to a reaction temperature within the range 280.degree. to 590.degree. C. Yellow phosphorus is continuously introduced into the ball mill through the hollow shaft in quantities per unit time which permit the reaction temperature prevailing inside the ball mill to be maintained without supply of heat from the outside. More particularly, decreasing quantities of yellow phosphorus are introduced per unit time at increasing temperature and increasing quantities of yellow phosphorus are introduced per unit time at decreasing temperature within the limits specified. Red phosphorus is allowed to cool inside the ball mill, water is poured over it and the whole is subjected to wet-grinding. An aqueous suspension of red phosphorus is finally removed from the ball mill.

Process for making red phosphorus

The invention relates to an apparatus for the production of phosphoric acid by subjecting yellow phosphorus to combustion inside a combustion tower, the apparatus comprising a cone-shaped shell with a flat bottom of acidproof material forming the combustion tower, the cone ratio of the shell being 1:10 to 1:12. An upwardly-directed off-gas outlet is secured to the lower portion of the shell and a plurality of downwardly directed spray nozzles is arranged so as to open through the middle portion of the shell into the interior of the combustion tower. An acid-receiving cup with an overflow weir is positioned near the upper end of the shell, the acid-receiving cup surrounding the combustion tower concentrically, being gas-tightly connected to, and supporting, a self-supporting cone-shaped tower cover having a passageway passed centrally through it. The overflow weir is formed of a tubular-annular structure disposed completely horizontally inside the acid-receiving cup. The tower cover forms, with respect to the horizontal, an angle .alpha. of at least 19.degree.. A water-cooled air inlet and a tubular holding means terminating in a phosphorus spray nozzle are hooked concentrically with respect to one another in, and are passed through the passageway in the cover.

Apparatus for the production of phosphoric acid

The invention provides stabilized pulverulent red phosphorus comprising a homogeneous blend of red phosphorus particles with a size of at most about 2 mm, aluminum hydroxide and a further metal hydroxide as oxidation stabilizers, wherein the metal hydroxide is lead hydroxide. The homogeneous blend contains aluminum hydroxide and lead hydroxide in a total proportion of about 0.1 to 6 weight %, based on the quantity of red phosphorus, the aluminum hydroxide and lead hydroxide, calculated as Al.sub.2 O.sub.3 to PbO, being used in a quantitative ratio of about 0.5 to 2.0.

Self-cleaning bucket wheel lock comprising several cells or compartments. The apparatus which permits coalescent material to be introduced into a closed apparatus comprises a casing with a material inlet and discharge outlet, and a rotor basket. The rotor basket is mounted in position on a drive shaft passing through the casing and an elastic hose is secured to the rotor basket. The hose enables the volume of each cell to be varied whenever the drive shaft is caused to rotate.

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Erftstadt, Germany

Ursus Thummler