Basf Aktiengesellschaft

Hermann Meyer

Gerd Wunsch

Volker Kiener

Gerhard Pforr

Wolfram Treptow

Gotthard Csizi

Hans Stark

Hugo Boehn

Wilhelm Goesele

Rainer Roemer

Sodium sulfate-containing residues are worked up by reducing the sulfate by a process in which the sulfate or a mixture or solution of the sulfate is thermally cleaved by adding oxygen, air or oxygen-enriched air at above 1000.degree. C., in particular above 1200.degree. C., under reducing conditions to give gaseous sulfides and oxides of sulfur as well as alkaline slag. The sulfur compounds contained in the gaseous reaction products can be further processed to sulfur, sulfur dioxide and sulfuric acid.

Working up sodium sulfate-containing residues

Anhydrous aluminum chloride is prepared by reacting .gamma.-alumina with carbon monoxide and chlorine and/or phosgene in a fluidized bed at from 400.degree. to 700.degree. C. The .gamma.-alumina used gives, with CuK.sub..alpha. radiation, an X-ray diffraction pattern whose intensity at the diffraction angle 2.sup..crclbar. =42.8.degree..+-.0.4.degree. divided by the intensity at the diffraction angle 2.sup..crclbar. =45.7.degree..+-.0.2.degree. is .ltoreq.0.38.

Preparation of anhydrous aluminum chloride

In an electrolysis cell with anodes and cathodes which are provided with openings, the cathode chamber is separated from the anode chamber by a diaphragm. The latter consists of a porous layer of oxides or oxidic compounds of the elements of sub-group 4B of the periodic table, of aluminum, of the rare earths or of chromium. The diaphragm is applied to that side of one of the electrodes which faces the counter-electrode.

Electrolysis cell

Manufacture of electrodes consisting of bases of valve metals with electrochemically active coatings applied thereto. The electrodes are pre-treated before the said coatings are applied, the pre-treatment comprising treating the base with hydrogen.

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Mannheim, Germany

Hermann Meyer