Hoechst Aktiengesellschaft

Messer Griesheim Gmbh

Hans-Werner Stephan

Gero Heymer

Klaus Lehr

Klaus Jodden

Ursus Thummler

Georg Elsner

Friedrich-Wilhelm Dorn

Hermann Klein

Gunther R Schimmel

Norbert Weferling

Reinhard Gradl

Eberhard Preisler

Bernd Lippsmeier

Gunter Reichert

Theodor Auel

Hilmar Roszinski

Gerhard Nolte

Herbert Panter

Manfred Wolter

Hermann Schrodter

Gerrit Marcks

Friedrich-Karl Frorath

Siegfried Pottkamper

Hartmut Behringer

In a process to transport acetylene which is dissolved in a solvent in a pressurized, insulated tank, the acetylene-to-solvent mass ratio of the solution is 0.30 at the maximum, whereby the solution has a temperature of up to -55.degree. C. [-67.degree. F.]. The surface of the solution in the tank is covered by a multilayer configuration consisting of pieces of floating material.

Process to transport acetylene

Tertiary alkylphosphines of the general formula R.sub.3 P, in which R stands for identical or different, linear, unsubstituted alkyl groups having 3 to 20 carbon atoms, with the proviso however that one of the alkyl groups may be a secondary butyl group, are made by reacting hydrogen phosphide PH.sub.3 with an appropriate alkene or alkenes in stoichiometric excess, if desired, at elevated temperature and under increased pressure in contact with a radical-yielding agent. 2,2'-azobis-(2-methylbutyronitrile) is used as the radical-yielding agent in the absence of whatever alien solvent.

Process for making tertiary alkylphosphines

The disclosure relates to a process for removing organic compounds from wet-processed phosphoric acid with the aid of an adsorbant. To this end the disclosure provides for the acid to be heated to at least 250.degree. C. prior to treating it with the adsorbant. The disclosure also relates to an apparatus for carrying out the process.

Process for removing organic contaminants from wet-processed phosphoric

The disclosure relates to a process for the discontinuous separation of a solid consisting predominantly of carbon black from its aqueous suspension by filtration. To this end, the disclosure provides for use to be made of a tube pressure filter which is operated under a final pressure of 30 to 100 bars.

Process for separating carbon black from an aqueous suspension

The disclosure relates to a process for making titanium dioxide concentrates from material containing titanium oxide and iron oxides. More particularly, the titanium oxide-containing material is calcined at temperatures of 870.degree. to 1300.degree. C., and then treated with a chlorine-containing gas at temperatures of 800.degree. to 1300.degree. C., if desired with addition of carbon.

Process for making titanium dioxide concentrates

A device for metering liquid yellow phosphorus into a rotating ball mill for the production of red phosphorus therein includes a stationary outer tubular structure surrounding an inner tubular structure rotatably mounted therein. A valve having a valve rod associated with it is installed within the inner tubular structure near its end close to the ball mill. A plug provided with a central bore receiving the valve rod is installed within the inner tubular structure near its end remote from the ball mill. A bellows surrounds a portion of the valve rod inside the inner tubular structure, the bellows being tightly connected to the plug and valve rod.

Metering device

The disclosure provides an electrolytic cell sealed in gas-tight and liquid-tight fashion. The cell is comprised of a box-shaped cell tank open at its top and provided with at least one intake duct, at least one overflow duct and at least one discharge duct. A cover is placed on the cell tank and two opposed flanges receiving electrode supporting frames are secured to the inside of the cell tank near the upper end thereof. A chemically resistant and electrically insulating coating is applied to the inside of the cover and cell tank and a plurality of semi-circular recessed grooves spaced apart from each other are formed in the upper rim portion of at least one of the side walls of the cell tank, the recessed grooves receiving semi-circular current beams projecting outwardly. A first elastic packing structurally conformed to the upper rim portion of the cell tank including the recessed grooves is placed thereon and a second elastic packing arranged at the underside of the cover co-operates with the upper side of the current beam and the first elastic packing whereby the electrolytic cell becomes gas tightly sealed. A main current rail is arranged to run outside the cell tank laterally with respect thereto and so as to be spaced therefrom, the rail providing large contact areas supporting the projecting end of the current beams. The electrode supporting frames and the current beams are electrically conducting inside the electrolytic ce

Electrolytic cell

Phosphorus in vapor form and phosphanes are separated from gas mixtures which consist of carbon monoxide, with or without hydrogen, nitrogen and steam. Concerned are more particularly the off-gases of phosphorus-producing furnaces. To this end, the gas mixture is admixed with at least the stoichiometric amount of oxygen and/or of oxygen-containing gases necessary to achieve conversion of the total phosphorus contained in the gas mixture to oxidation level V. The resulting mixture is introduced into a reaction zone maintained at a temperature within the range 200.degree. to 700.degree. C. and allowed to remain therein over a period of 0.5 to 20 seconds. Resulting phosphorus-V compounds are finally separated from the gas mixture.

Process for removing phosphorus in vapor form and phosphanes from gas

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 aqueous phosphorous acid solutions by admixing an aqueous sodium phosphite solution with hydrochloric acid. More specifically, phosphorous acid solutions substantially free from sodium in hydrochloric acid are produced by introducing hydrogen chloride, into the sodium phosphite solution until the latter is saturated therewith and separating precipitating sodium chloride from the resulting phosphorous acid solution in hydrochloric acid.

Production of phosphorous acid

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

Organic phosphines are produced by reacting an alkylene, cycloalkylene or aralkylene in the presence of a free radical-yielding catalyst. More specifically, a pressure reactor, which is provided in its interior with mixing elements, kept free from oxygen, and subdivided so as to comprise an upper cooling zone and a lower reaction zone, is continuously supplied from above with (a) a solution of the alkylene, cycloalkylene or aralkylene and the catalyst in an inert solvent, and (b) a stoichiometric excess of hydrogen phosphide, the said (a) and (b) reactants being supplied jointly with but separately from one another; the (a) and (b) reactants are mixed in the upper cooling zone of the reactor at about 0.degree. to 35.degree. C. and under a PH.sub.3 -pressure of about 80 to 300 bars; the resulting mixture, which travels downwardly in the reactor, is reacted in the lower reaction zone at about 90.degree. to 190.degree. C., the reactants being allowed to remain in the reactor for a period of time about 13 to 15 times longer than the half life period of the catalyst; the reaction mixture is removed through the bottom portion of the reactor and subjected to distillation so as to separate the organic phosphines.

Continuous production of organic phosphines

O,O-dialkylthionophosphoric acid chlorides are produced by chlorinating a dialkyldithiophosphoric acid in two stages. In the first stage, the acid is reacted with chlorine in a molar ratio of 1:1.15 to 1:1.50, resulting sulfur is separated, the liquid phase is admixed with a distilled product of a previous batch chlorinated in the second stage and with a further 0.25 to 0.7 mol of O,O-dialkyldithiophosphoric acid per mol of acid initially used, and desirable final product is distillatively separated from said mixture. In the second stage, the distillation residue of the first stage is reacted with a total proportion of 0.9 to 1.0 mol of chlorine per mole of acid initially used, precipitated sulfur is separated from the second stage chlorination product, the liquid phase is distilled off, and resulting distillate is recycled to the first chlorination stage.

Production of O,O-dialkylthionophosphoric acid chlorides

Production of substantially water-insoluble linear ammonium polyphosphates of the general formula (NH.sub.4 PO.sub.3).sub.n, in which n is a number between 10 and 1000. To this end, substantially equimolecular proportions of ammonium orthophosphate and phosphorus pentoxide are reacted by heating them to temperatures within the range 170.degree. and 350.degree.C in the presence of gaseous ammonia. The reaction is effected while continuously and simultaneously mixing, kneading and comminuting the reaction material in a reactor. The reactor is closed, provided with means for the supply of solid feed material, a gas inlet and a gas outlet, a discharge opening for the removal of final product, and with mixing, kneading and comminuting implements which are rotatably secured to the inside of the reactor.

Process for the production of substantially water-insoluble linear

Production of 2-phenyl-ethylene phosphonic acid by reacting styrene with phosphorus pentachloride in a molar ratio of about 1 : 2 in liquid phase and hydrolyzing the resulting complex 2-phenyl-ethylene phosphonic acid tetrachloride with water. The reaction is more particularly started with the use as the liquid phase of the equimolar mixture of 2-phenyl-ethylene phosphonic acid dichloride and phosphorus oxychloride obtained as an intermediary product; styrene and phosphorus pentachloride are introduced thereinto with continuous agitation; resulting complex 2-phenyl-ethylene phosphonic acid tetrachloride is partially hydrolyzed by adding a predetermined quantity of water to an equimolar mixture of 2-phenyl-ethylene phosphonic acid dichloride and phosphorus oxychloride; a portion of the resulting clear solution is continuously used as the liquid phase and phosphorus oxychloride is continuously distilled off under reduced pressure from the balance portion of the solution; remaining 2-phenyl-ethylene phosphonic acid dichloride is hydrolyzed by continuous addition of overstoichiometric proportions of water to an aqueous solution of 2-phenyl-ethylene phosphonic acid; the aqueous solution is cooled and crystalline phosphonic acid is precipitated therefrom.

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Cologne, Germany

Hans-Werner Stephan