Abstract: Nanoscale, pyrogenically produced oxides and/or mixed oxides having a BET surface area of between 1 m2/g and 600 m2/g and a chloride content of less than 0.05 wt. % are produced by converting organometallic and/or organometalloid substances into the oxides at temperatures of above 200° C. The oxides may be used as a polishing agent in the electronics industry (CMP).

Abstract: A suspension, dispersion or emulsion is introduced into a burner. An optionally two-stage after-treatment is then carried out. The resulting powder can be employed as a catalyst.

Abstract: Process and apparatus for the thermal treatment of pulverulent substances, in which the pulverulent substance is dispersed in a carrier gas and is passed in a continuous manner through a heated reactor where it is thermally treated and is then quenched by a cooling medium and is collected in a gas-solids separating unit.

Abstract: A process for preparing grit blasting particles coated with titanium dioxide by sinter-fusing titanium dioxide on the surface of grit blasting particles made of a base material. A mixture of finely divided titanium dioxide and grit blasting particles is passed continuously through the flame in a flame reactor, with the aid of conveying air, wherein the titanium dioxide is sinter-fused on the surface of the grit blasting particles over an average residence time of 0.1 to 5 seconds in a temperature range from 600 to 1200° C. An increase in the adhesive bond between metal framework and a facing material made of plastics in dentures can be achieved when metal framework is grit blasted with a grit blasting agent containing titanium dioxide coated grit blasting particles and then the grit blasted and titanium dioxide coated surface is treated with a silane bonding agent.

Abstract: A suspension, dispersion or emulsion is introduced into a burner. A two-stage after-treatment is then carried out. The resulting powder can be employed as a catalyst.

Abstract: A process for preparing grit blasting particles coated with titanium dioxide by sinter-fusing titanium dioxide on the surface of grit blasting particles made of a base material. A mixture of finely divided titanium dioxide and grit blasting particles is passed continuously through the flame in a flame reactor, with the aid of conveying air, wherein the titanium dioxide is sinter-fused on the surface of the grit blasting particles over an average residence time of 0.1 to 5 seconds in a temperature range from 600 to 1200° C. An increase in the adhesive bond between metal framework and a facing material made of plastics in dentures can be achieved when metal framework is grit blasted with a grit blasting agent containing titanium dioxide coated grit blasting particles and then the grit blasted and titanium dioxide coated surface is treated with a silane bonding agent.

Abstract: Granular products with individual granules with virtually spherical particles of a homogeneous density distribution are produced by converting solids into suspensions, atomizing the suspensions and drying them by sublimation drying.

Abstract: Nanoscale, pyrogenically produced oxides and/or mixed oxides having a BET surface area of between 1 and 600 m2/g and a chloride content of less than 0.05 wt. % are produced by converting organometallic and/or organometalloid substances into the oxides at temperatures of above 200° C.

Abstract: A suspension, dispersion or emulsion is introduced into a burner. A two-stage after-treatment is then carried out. The resulting powder can be employed as a catalyst.

Abstract: A method of producing hydrogen cyanide by the gas-phase reaction of methane with ammonia at elevated temperature and an ammonia/methane ratio of 1.001 to 1.1. The conducting of the gaseous reaction mixture through a corona discharge causes the reaction to start at temperatures below 1000.degree. C. without the action of a catalyst. This results in considerable savings of the necessary investment expenses as well as of the running costs for energy.

Abstract: An apparatus (10) to carry out a process for the in situ generation of agglomerate structures and the controlled influencing of the resulting agglomerates contains a closed flow duct (12) through which is directed an aerosol containing particles (14). For the purpose of the bipolar charging of the aerosol, at least one electrode pair (20, 22) is arranged in the flow duct (12), the electrode (20) being wired, so as to be ungrounded, to the negative pole of a current source, the strength of which is sufficient to produce a corona discharge between the electrodes (20 and 22). The electrodes (20 and 22) of each electrode pair are designed to be needle-shaped and are arranged to be insulated with respect to the flow duct walls, such that their tips (26) are disposed opposite each other.

Abstract: A gas phase process for the production of titanium dioxide powders having well-controlled crystalline and surface area characteristics is disclosed. In this process, which is preferably carried out in a laminar diffusion flame reactor, vapor phase TiCl.sub.4 and oxygen are mixed in a reaction area which is heated externally. The titanium dioxide powder formed is then collected. It is preferred that the heat source used be a hydrocarbon fueled (e.g., methane) flame. Optionally, a vapor phase dopant (such as SiCl.sub.4) may be added to the reaction mixture to desirably affect the physical properties of the titanium dioxide produced. In a particularly preferred embodiment, a corona electric field is positioned across the area where the combustion reaction takes place (i.e., the reaction area). High anatase, high surface area titanium dioxide powders made by this process are excellent photocatalysts. The products of this process and the use of those products as photocatalysts are also disclosed.

Abstract: An apparatus (10) to carry out a process, in particular for the electrically induced agglomeration of gas-borne particles, contains a closed flow duct (12) through which is directed an aerosol containing particles (14). For the purpose of the bipolar charging of the aerosol, at least one electrode pair (20, 22) is arranged in the flow duct (12), the electrode (20) being wired, so as to be ungrounded, to the negative pole of a current source, the strength of which is sufficient to produce a corona discharge between the electrodes (20 and 22). The electrodes (20 and 22) of each electrode pair are designed to be needle-shaped and are arranged to be insulated with respect to the flow duct walls, such that their tips (26) are disposed opposite each other.

Abstract: A gas phase process for the production of titanium dioxide powders having well-controlled crystalline and surface area characteristics is disclosed. In this process, which is preferably carried out in a laminar diffusion flame reactor, vapor phase TiCl.sub.4 and oxygen are mixed in a reaction area which is heated externally. The titanium dioxide powder formed is then collected. It is preferred that the heat source used be a hydrocarbon fueled (e.g., methane) flame. Optionally, a vapor phase dopant (such as SiCl.sub.4) may be added to the reaction mixture to desirably affect the physical properties of the titanium dioxide produced. In a particularly preferred embodiment, a corona electric field is positioned across the area where the combustion reaction takes place (i.e., the reaction area). High anatase, high surface area titanium dioxide powders made by this process are excellent photocatalysts. The products of this process and the use of those products as photocatalysts are also disclosed.