Deutsche Gold- Und Silber-scheideanstalt Vormals Roessler

Degussa Aktiengesellschaft

Hans Klebe

Gerd Knippschild

Hubert Schuster

Ludwig Lange

Bernhard Beck

Gerhard Fratzer

Erwin Dold

Josef Schmid

Dieter Schutte

Dieter Kerner

Axel Volling

Detlev Koth

Jean Diether

Manfred Schmid

Pyrogenically produced silica after separation of the hydrogen halide is mixed with nitrogen and conveyed into a cyclone. After separation of the gases, which are returned into the cooling stretch of the production apparatus, the silica is first mixed with organohalosilane and nitrogen and subsequently with steam and nitrogen. Subsequently the hydrophobization reaction is carried out in known manner in a fluidized bed reactor. The reaction waste gases are returned into the cyclone.

Process for the hydrophobization of pyrogenically produced silica

There is produced a stabile per salt which contains simultaneously sodium percarbonate and sodium perborate by introducing a solution supersaturated with both sodium percarbonate and sodium perborate to nuclei which consist of sodium percarbonate and/or sodium perborate.

Process for the production of a stable per salt

Monolithic carrier matrixes are formed from high grade steel, consisting of alternating smooth and corrugated layers of sheet metal and/or screen cloth, which may be combined with layers of smooth screen cloth or of smooth or corrugated sheet metal, wherein the layers may be coated on their surfaces with a catalysis-promoting carrier material. These carrier matrixes may be used to produce catalysts for the purification of exhaust gases.

Apparatus containing a carrier matrix for catalysts

There is provided a pyrogenic process for the production of finely divided oxide of a metal and/or a metalloid in which there is employed as the starting material a vaporizable halogen compound of a metal and/or metalloid. Because of the starting material there is formed elemental halogen which is an impurity in the oxide formed. To remove the halogen there is supplied to the cooling section of the production plant a mixture of hydrogen and inert gas.

Process for the pyrogenic production of finely divided oxide of a metal

An improved carrier matrix for catalysts is described wherein layers are disposed one on top of the other consisting of highly temperature resistant and non-scaling steel formed into a smooth screen into which closed hollow or open supporting profiles of a larger cross section than the screen are woven in or on at parallel distances. Layers of screens provided with profiles may be combined with layers of flat screens or smooth or corrugated sheet metal. The carrier matrix may be coated with a catalytically active carrier such as gamma-aluminum oxide and then receive a coating of a catalytically active metal whereby the resulting product may be used to treat auto exhaust gases for purification.

Carrier matrix for catalysts and a process for the production of same

Carrier matrix for catalysts and process for its production

In case of the pyrogenous production of metal oxides or metalloid oxides, whenever a halogen compound is used as a starting material, an elementary halogen is formed as a byproduct. This may be converted in the cooling section of the reaction apparatus with hydrogen into hydrogen halide. For a better temperature control and prevention of uncontrolled deflagration of the hydrogen in case of the halogen detonating gas reaction, according to the invention the hydrogen is introduced into the cooling section by means of a double jacket pipe, whereby an inert gas is introduced additionally by way of the interstice between the inside wall and the outside jacket of the double jacket pipe into the cooling section.

Process for the pyrogenous production of very finely divided oxides of a

There are prepared sodium percarbonate particles comprising a sodium percarbonate nucleus encased in a layer of a mixture of dehydrated sodium perborate and sodium silicate prepared by spraying the sodium percarbonate with a supersaturated solution of sodium perborate and a sodium silicate solution and drying to at least partially remove the added water.

Process for the production of stabilized sodium percarbonate

Sodium percarbonate is stabilized with highly dispersed silica. The sodium percarbonate containing 1 to 10 weight % of water is mixed with the silica and subsequently dried. The highly dispersed silica has an average particle size of 2-100 microns, preferably 7-20 microns. The product is sodium percarbonate particles encased by a sodium silicate jacket.

Process for the stabilization of sodium percarbonate

There are prepared sodium percarbonate particles comprising a sodium percarbonate nucleus encased in a layer of dehydrated sodium perborate or a mixture of dehydrated sodium perborate and sodium silicate with or without additional water binding materials chemically inert to sodium percarbonate and dehydrated sodium perborate.

Sodium percarbonate particles (A)

There are prepared sodium percarbonate particles consisting essentially of a sodium percarbonate nucleus encased in a layer of sodium silicate and sodium percarbonate and/or sodium tripolyphosphate.

Sodium percarbonate particles (B)

A compact, abrasion resistant sodium percarbonate is produced by reacting sodium carbonate with hydrogen peroxide. There is employed a solution saturated in sodium percarbonate and also containing (1) sufficient sodium carbonate that there is present sodium carbonate decahydrate as a solid phase, (2) sodium chloride in an amount of 100 to 200 grams per liter, (3) an active oxygen stabilizer and (4) sodium hexametaphosphate in an amount of 0.1 to 1.9 grams per liter. There is added hydrogen peroxide in an amount about equivalent to the dissolved sodium carbonate which results in a supersaturated solution of sodium percarbonate. The supersaturation is broken down by precipitation of sodium percarbonate during the addition of the hydrogen peroxide and up to 60 minutes thereafter. The entire process is carried out at a substantially constant temperature within the range of 10.degree. to 20.degree. C. The precipitated sodium percarbonate is separated and dried and the mother liquor can be returned to the first step of the process.

Process for the production of compact, coarse sodium percarbonate

A compact, abrasion resistant sodium percarbonate is produced continuously by reacting sodium carbonate and hydrogen peroxide in the presence of sodium percarbonate inocculant seeds, sodium chloride, an active oxygen stabilizer and sodium hexametaphosphate at 10-20.degree. C, the process comprises feeding into the preliminary inocculant and aqueous hydrogen peroxide solution containing an active oxygen stabilizer and simultaneously either (1) a filtered solution saturated in sodium carbonate and containing 40-100 grams per liter of sodium percarbonate, 0.1-1.0 gram of sodium hexametaphosphate per liter, 100-200 grams of sodium chloride per liter and an active oxygen stabilizer or (2) a mother liquor containing 40-100 grams of sodium percarbonate per liter, 0.1-1.0 gram of sodium hexametaphosphate per liter, 100-200 grams of sodium chloride per liter and an active oxygen stabilizer, with the proviso that when the mother liquor is employed there is also fed into the preliminary inocculant such an amount of calcined soda that no sodium carbonate decahydrate forms as a solid phase in the preliminary inocculant, the amount of hydrogen peroxide employed being approximately equivalent to the amount of dissolved sodium carbonate for reaction, the temperature is maintained constant during the entire process of precipitating sodium percarbonate, the supersaturation initially formed upon addition of the hydrogen peroxide being reduced by the precipitation of the sodium percarbonate, the precipitated sodium per carbonate is separated and dried.

Continuous process for the production of a compact, coarse sodium

Process for the production of a finely divided oxide of a metal or silicon by the hydrolytic conversion of a volatile corresponding metal halide or silicon halide in a flame, said process comprising feeding the volatile halide in a mixture with a combustible hydrogen-containing gas and air or oxygen to a burner provided with a mouth emitting a flame, burning the mixture in a fire tube to form a first portion of water vapor, said burner surrounded by an annular chamber forming a nozzle through which hydrogen is passed to keep the mouth of the burner free of attachments of solid substances, the quantity of oxygen or air being sufficient for the practically complete combustion of the combustible gas, and the quantities of oxygen or air and combustible gas being sufficient to produce the first portion of water vapor which will at least suffice for the hydrolysis of the volatile halides, and further wherein said flame is allowed to burn in an atmosphere consisting of gases containing a second portion of water vapor, to avoid the formation of halogen gas in waste gases and separating the resulting oxide from other reaction products. The finely divided oxides are useful as additives and fillers in the manufacture of coatings, adhesives and elastomers.

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Rheinfelden, Germany

Hans Klebe