Dynamit Nobel Aktiengesellschaft

Arnold Lenz

Walter Rogler

Rainer Haase

Gerhard Kreuzburg

Otto Bleh

Volker Hunger

Otto Ackermann

Klaus Deneke

Wilhelm Joch

Ranier Haase

Harald Von Metnitz

Karl-Theo Von Meszoly

Erich Termin

A process for separating radioactive impurities from baddeleyite to obtain zirconium dioxide containing only traces of radioactive impurities, comprising grinding the baddeleyite preferably to a particle size of a maximum of 2% greater than 0.06 mm and then treating it directly with a 10 to 60% by weight aqueous alkali hydroxide solution at elevated temperatures below the boiling point of said solution at temperatures of 80.degree. to 140.degree. C. for 2 to 15 hours or until the desired degree of purity of the zirconium dioxide is obtained. In a preferred embodiment, sodium hydroxide is utilized and the ground baddeleyite preliminarily has been purified to the content of greater than 98% (zirconium dioxide+hafnium dioxide) by known methods.

Process for the separation of radioactive impurities of baddeleyite

Method of preparing granular quartz glass which comprises heating a porous granulated silica gel having an alkoxy group content equal to or less than 1 weight percent and a total impurity content of less than 1 part per million, the porous granulated silica gel obtained by hydrolysis of an orthosilicic acid ester of an aliphatic alcohol at a temperature up to 1400.degree. C.

Granular quartz glass product

A process for preparing an orthosilicic acid tetraester of a monoalkyl ether of an aliphatic glycol having 2 to 6 carbon atoms which comprises contacting silicon, iron silicide or ferrosilicon with a monoalkyl ether of an aliphatic glycol having 2 to 6 carbon atoms in the aliphatic chain in the presence of the corresponding orthosilicic acid tetraalkoxy alkyl ether at a temperature between 125 and 250.degree. C.

Process for the preparation of orthosilicic acid tetraalkoxyalkyl esters

A process for preparing an orthosilicic acid tetraalkyl ester having 2 to 6 carbon atoms in the ester group which comprises contacting metallic silicon with an alcohol corresponding to the ester group in the presence of the corresponding alkali alcoholate:

Method of preparing orthosilicic acid alkyl esters

A process for the preparation of an aqueous alkali metal polysilicate solution having an SiO.sub.2 : alkali metal oxide mole ratio of 2.5 - 5.5 : 1 and a silica content of 16 - 23% by weight which comprises contacting a tetraalkoxysilane of the formula Si(OR).sub.4 wherein each R is independently a straight or branched-chain alkyl group of 1 to 3 carbon atoms with an aqueous alkali metal hydroxide solution at a temperature between room temperature and the boiling point of the reaction mixture and at a temperature up to 100.degree. C. distilling over alcohol formed by the reaction of the silane with the alkali metal hydroxide.

Aqueous solutions of alkali polysilicates

Process for the production of granular quartz glass

Process of producing a naphthyridine or quinoline compound of the formula: ##STR1## wherein R.sub.2, R.sub.3, R.sub.4, and R.sub.6 can be alkyl, and R.sub.1 is nitrogen or CH. The corresponding pyridyl- or phenylaminomethylenemalonic acid diester is cyclized to yield said compound and an alcohol. The malonic acid diester at below reaction temperature is added to a solvent, e.g., diphenyl benzene, at above reaction temperature in proportion so that the mixture attains reaction temperature. Good yields at high throughputs are achieved.

Process of performing cyclization reactions using benzyl or pyridylamino

A process for the preparation of an alcohol-free alkali or alkaline earth metal alcoholates dissolved in inert solvent which comprises contacting at least an equimolar amount of an alkali or alkaline earth metal dissolved in an inert solvent with an alcohol at an elevated pressure and at a temperature of at least that at which crystal alcohol splits off from the corresponding alkali or alkaline earth metal alcoholate and below the temperature at which said alcoholate decomposes under the prevailing pressures.

Method for the preparation of alcohol-free alkali and alkaline earth

The hydrogenation of benzene dicarboxylic acid mono and diesters to corresponding cyclohexene dicarboxylic acid mono and diesters by carrying out the hydrogenation in the active and effective presence of alkalimetal amalgam and an alcohol in a substantially anhydrous environment. The hydrogenation reaction medium should be a mixture of the above referred to alcohol and an aromatic hydrocarbon such as toluene.

Process for the manufacture of cyclohexene dicarboxylic acid esters

Porous silicic acid having a specific surface of about 50 to 1000 m.sup.2 /g and having an anion content below the chemically determinable limit of detection is made by hydrolyzing methyl or ethyl silicate or polymethyl or polyethyl silicate with about 70 to 120% of the stoichiometric amount of water with moderate stirring. Hydrolysis activators such as acids or bases may be present as well as alcoholates of oxides of transition metals which then appear in the end product. Alcohol may also be present to facilitate hydrolysis. The products are characterized by marked purity and their specific surface can be closely and reproducibly controlled.

Porous silicic acid and its production

A process for the preparation of a vanadyl alcoholate which comprises contacting vanadium pentoxide with an alcohol in the presence of an orthoester of the formula R' . C(OR').sub. 3 wherein:

Process for the manufacture of vanadyl alcoholates

A process for the preparation of an aqueous alkali metal polysilicate solution having an SiO.sub.2 : alkali metal oxide mole ratio of 2.5 - 5.5 : 1 and a silica content of 16 - 23% by weight which comprises contacting a tetraalkoxysilane of the formula Si(OR).sub.4 wherein each R is independently a straight or branched-chain alkyl group of 1 to 3 carbon atoms with an aqueous alkali metal hydroxide solution at a temperature between room temperature and the boiling point of the reaction mixture and at a temperature up to 100.degree.C. distilling over alcohol formed by the reaction of the silane with the alkali metal hydroxide.

Method of manufacturing aqueous solutions of alkali polysilicates

Alkali metal hydrides, obtained by reacting alkali metals in liquid form with hydrogen in the presence of alkali metal hydrides, are obtained in coarsely crystalline form by continuously introducing into the reaction vessel containing constantly agitated alkali metal hydride only so much alkali metal in liquid form which corresponds stoichiometrically to the amount of hydrogen reacted and maintaining the unreacted metal concentration at 3 weight percent or less of the pre-introduced metal hydride present. In preferred aspect, the pre-introduced metal hydride is agitated by mixing means at a circumferential velocity of 0.5 to 2 meters/second and maintained at 250.degree.-310.degree.C., to yield hydride crystals in the range of 100 to 1000 microns. The hydride thus obtained may be ground in an inert hydrocarbon mixture to a finer particle material still having a relatively low surface area and recovered as a stabilized, non-sticking, non-self ignitable alkali metal hydride product.

Growing community of inventors

Cologne-Stammheim, Germany

Arnold Lenz