Basf Aktiengesellschaft

Gerhard Pforr

Hans Stark

Erfried Voelkl

Hermann P&uuml;tter

Luise Spiske

Dieter Schl&auml;fer

G&uuml;nther Huber

Max Appl

Hermann Meyer

Gerhard Peschau

Gerd Duembgen

Wilhelm Goesele

Rainer Roemer

Guenter Schippmann

A process for preparing sodium and aluminum chloride electrochemically is described in which, in an electrolytic cell containing aluminum as an anode and sodium as a cathode which are separated from one another by a sodium ion-conducting solid electrolyte, a fused electrolyte essentially containing sodium tetrachloroaluminate is electrolyzed in the anode compartment, aluminum chloride formed in this process is evaporated from the electrolytic cell and sodium is removed from the cathode compartment.

Electrolytic cell

Electrolytic method for the production of sodium and aluminum chloride

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

A flange coupling for joining multi-layer apparatus sections or pipeline sections, in which corrosive and hot gases are handled, consists of an inner lining of glass which is resistant to thermal shock, or of quartz, which is surrounded by an outer metal jacket, the interspace between the outer jacket and the lining being packed with a heat-insulating material. In the region of the ends of the lining, refractory bricks which surround the lining, support it but do not touch it over the entire surface are provided between the lining and the outer jacket; the lining, at one or both ends, does not terminate flush with the refractory bricks, and the refractory bricks surrounding the lining terminate at least substantially flush with the surrounding outer jacket, the two ends of which each merge into a flange coupling.

Flange coupling

De-dusting of gases is carried out in an apparatus containing a granular-bed filter, the pourable granular filter medium flowing downward through the bed. The apparatus comprises a vessel of rectangular cross-section with a vertical side wall (4) extending from the top to the bottom. A partition (5), arranged parallel to the side wall (4), extends from the upper end of the vessel into the interior of the vessel. The remaining three side walls of the vessel extend - at least starting from a level corresponding to the lower end of the partition (5), taperingly downward to the outlet (9). The partition (5) is supported by the two walls adjacent to the vertical wall and forms, together with these and with the talus (7) of the filter medium, which arises at the lower end of the partition, a chamber (3) into which the inlet (2) for the gas to be purified opens. At the inlet (10) for the filter medium, located at the upper end of the partition, a further talus (12) of the filter medium forms, defining a collecting chamber (16), in which the outlet (17) for the purified gas is located.

Apparatus for de-dusting gases

To destroy phosgene contained in gases, the phosgene is decomposed catalytically in the presence of active carbon by hydrolysis with water vapor, in the absence of liquid water, at above the dew point of water.

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Ludwigshafen, Germany

Gerhard Pforr