Abstract: The present invention relates to oxidation-stable iron oxide pigments which have a coating of at least one organic substance, to their preparation and to their use.

Abstract: The present invention relates to oxidation-stable iron oxide pigments which have a coating of at least one organic substance, to their preparation and to their use.

Abstract: The present invention relates to a pigment/auxiliary combination having an improved chroma and/or relative colour strength, to its production and to its use.

Abstract: The present invention relates to a process for preparing yellow iron oxide pigments by the precipitation method from iron(II) chloride or iron(II) sulphate raw material and calcium carbonate precipitant.

Abstract: Mercury is removed from solutions contaminated with mercury, the solution contaminated with mercury being introduced into a distillation column above the column bottom, solvent being distilled off and solution depleted in mercury being stripped off at the column bottom.

Abstract: Mercury is removed from solutions contaminated with mercury by filtration through a carbon filter consisting of electrode graphite.

Abstract: The invention relates to a reaction vessel (1) for producing a sample, in particular a crystal, from a substance in solution or in liquid form, having several reaction chambers (6) each forming a separate gas chamber, consisting of at least one housing part, and each reaction chamber (6) has a reservoir (7) and several reaction areas (8) co-operating therewith, connected to one another and to the reservoir (7) in order to exchange gas. The reservoirs and the reaction areas co-operating with them are disposed immediately adjacent to one another in rows, distributed in a predeterminable, identical manner, these rows running parallel with one another. Each row of reservoirs (7) therefore co-operates with at least one row of reaction areas (8).

Abstract: Alkali metal alkoxides are prepared by reacting alkali metal amalgam with alcohol in the presence of a catalyst comprising porous iron.

Abstract: The present invention relates to a process for preparing yellow iron oxide pigments by the precipitation method from iron(II) chloride or iron(II) sulphate raw material and calcium carbonate precipitant.

Abstract: Alkali metal methoxides are prepared from aqueous alkali metal hydroxide, which may have been admixed with methanol, and methanol in a reaction column having at least 5, preferably from 15 to 30, theoretical plates between the feed point for the aqueous alkali metal hydroxide and the feed point for the methanol. The gaseous methanol/water mixture formed in the reaction is fractionated in a rectification column. In one variant of the invention, the trays chosen for the reaction column configured as a bubble cap tray, valve tray or sieve tray column are trays in which not more than 5%, preferably <1%, of the liquid rains through the respective trays. In another variant of the process of the present invention, the double-wall reaction column has a temperature in the double wall which is from 3 to 10° C.

Abstract: The invention relates to a catheter arrangement for invasive medical treatment for introducing and controlling a guide wire in a vessel branch or vessel entry by bending the guide wire. The catheter arrangement comprises two catheters, each having a distal end and a proximal end and a lumen, wherein the two catheters are embodied as an inner catheter 3 and an outer catheter 2 extending coaxially within one another and arranged so as to be moveable relative to one another in an axial direction, wherein the inner catheter 3 has a pre-bent distal tip 3a of a bendable material and the outer catheter 2 has a continuous lumen 22 extending from the proximal end 20 to the distal end 21 for receiving the inner catheter 3, wherein both catheters 2, 3, at a spacing from the distal end 21, have lateral openings 23, 33 for passing the guide wire F therethrough.

Abstract: Alkali metal alkoxides are prepared by reacting alkali metal amalgam with alcohol in the presence of a catalyst comprising iron having a carbon content of at least 0.3% by weight.

Abstract: A process for preparing a high purity lithium salt from lithium carbonate comprises steps A to D as defined hereinbelow: A: treating a mixture comprising lithium carbonate and water by means of CO2 to obtain an aqueous mixture comprising lithium bicarbonate, B: passing said aqueous mixture comprising lithium bicarbonate through an ion exchanger module, C: precipitating lithium carbonate from the ion exchange module treated lithium bicarbonate mixture obtained in step B, and D: working up the precipitated lithium carbonate or converting the precipitated lithium carbonate into some other high purity lithium salt.

Abstract: A stent made of a self-expandable or balloon-expandable metal mesh fabric that can be widened to a diameter larger than that of the descending aorta. The stent has a flexible lining of vessel-replacing material, wherein the lining covers it at least partly in longitudinal direction and forms a tubular segment which projects beyond the end of the stent at least at one end and which functions as the vascular prosthesis. Such implantable arrangements (1) make it possible to achieve short surgical times, especially during the treatment of aortic arch aneurysms involving the cephalic arteries.

Abstract: A stent for treating vascular stenoses. The stent is insertable into regions of arterial vascular systems close to the ostium. The stent comprises a tubular expandable element made of a mesh fabric which is insertable into the inlet or an outlet of a vessel. The proximal end of the stent is expandable to a trumpet-shaped structure. Using the inventive stent, it is possible in a simple, rapid and safe manner to treat stenoses close to the ostiums of arterial vascular systems so that the entire stenosed region can be covered with a stent.

Abstract: Highly pure LiBF4 is prepared by preparing a solution of BF3 etherate in diethyl ether, suspending LiF in this solution, reacting to give solid LiBF4, and then separating off the solid LiBF4 formed. The LiBF4 prepared is used for producing lithium ion batteries.

Abstract: The invention relates to a reaction vessel (1) for producing a sample, in particular a crystal, from a substance in solution or in liquid form, having several reaction chambers (6) each forming a separate gas chamber, consisting of at least one housing part, and each reaction chamber (6) has a reservoir (7) and several reaction areas (8) co-operating therewith, connected to one another and to the reservoir (7) in order to exchange gas. The reservoirs and the reaction areas co-operating with them are disposed immediately adjacent to one another in rows, distributed in a predeterminable, identical manner, these rows running parallel with one another. Each row of reservoirs (7) therefore co-operates with at least one row of reaction areas (8).

Abstract: Alkali metal methoxides are prepared from aqueous alkali metal hydroxide, which may have been admixed with methanol, and methanol in a reaction column having at least 5, preferably from 15 to 30, theoretical plates between the feed point for the aqueous alkali metal hydroxide and the feed point for the methanol. The gaseous methanol/water mixture formed in the reaction is fractionated in a rectification column.

Abstract: The invention relates to a process for preparing alkali metal alkoxides by reacting alkali metals with alcohols in the presence of a catalyst, preferably a transition metal salt and especially iron(III) chloride.

Abstract: In the process for the preparation of vinylsilanes by reacting acetylenic hydrocarbons with silanes which have at least one silicon-bonded hydrogen atom in the liquid phase in the presence of a catalyst, the silane is added to the liquid phase. In particular, the reaction is carried out at superatmospheric pressure, and the spent acetylenic hydrocarbon is replenished during the reaction while maintaining a pressure which is constant during the entire reaction.