Abstract: Methods can be used for producing three-dimensional objects by powder bed fusion, using inks containing superparamagnetic particles and solvents. Sintering is performed by a magnetic field having a frequency of 50 kHz to 5 GHz.

Abstract: The present invention relates to a method of purifying strong acids or strongly acidic media to remove di- and higher valent metal ions, which can be used within the context of the production of high-purity silica. The invention further relates to the use of special ion exchangers for carrying out the method according to the invention and the resultant high-purity silicas.

Abstract: The present invention relates to a process for preparing aqueous colloidal silica sols of high purity from silicate solutions, to aqueous colloidal silica sols with a specific profile of impurities, and to the use thereof. The invention further encompasses high-purity aqueous silica obtained as an intermediate in the course of the purification process, high-purity silicon dioxide obtainable by dewatering, and the use thereof.

Abstract: Organofunctional silicon particles are covalently functionalized on their surface with at least one organic compound, for example a plurality of —O—(C1-C48)-alkyl compounds. The functionalization of the surface of the silicon particles makes it possible to adjust the properties of fluids in terms of their profile of properties by addition of the modified silicon particles. For instance, the alkoxy-functionalized silicon particles may preferably be added to a motor oil as additives for reducing viscosity.

Abstract: It has been found that conventional cheap waterglass qualities in a strongly acidic medium react to give high-purity silica grades, the treatment of which with a base leads to products which can be processed further to give glass bodies with low silanol group contents.

Abstract: The present invention relates to a method of purifying strong acids or strongly acidic media to remove di- and higher valent metal ions, which can be used within the context of the production of high-purity silica. The invention further relates to the use of special ion exchangers for carrying out the method according to the invention and the resultant high-purity silicas.

Abstract: The present invention relates to a method of purifying strong acids or strongly acidic media to remove di- and higher valent metal ions, which can be used within the context of the production of high-purity silica. The invention further relates to the use of special ion exchangers for carrying out the method according to the invention and the resultant high-purity silicas.

Abstract: It has been found that conventional cheap waterglass qualities in a strongly acidic medium react to give high-purity silica grades, the treatment of which with a base leads to products which can be processed further to give glass bodies with low silanol group contents.

Abstract: The present invention relates to a process for preparing aqueous colloidal silica sols of high purity from silicate solutions, to aqueous colloidal silica sols with a specific profile of impurities, and to the use thereof. The invention further encompasses high-purity aqueous silica obtained as an intermediate in the course of the purification process, high-purity silicon dioxide obtainable by dewatering, and the use thereof.

Abstract: The present invention relates to a process for producing SiO2 mouldings, comprising the preparation of a free-flowing aqueous SiO2 composition, solidification of the aqueous SiO2 composition and drying of the solidified SiO2 composition, wherein the aqueous SiO2 composition is a self-assembly composition. The present invention further relates to a moulding obtainable by the process according to the invention.

Abstract: The present invention relates to an improved process for producing silicon, preferably solar silicon, using novel high-purity graphite mouldings, especially graphite electrodes, and to an industrial process for production of the novel graphite mouldings.

Abstract: The present invention relates to processes for industrial pyrolysis of a carbohydrate or carbohydrate mixture with addition of amorphous carbon, to a pyrolysis product thus obtainable and to the use thereof, especially as a reducing agent in the production of silicon from silica and carbon at high temperature.

Abstract: The invention relates to a complete method for producing pure silicon that is suitable for use as solar-grade silicon, comprising the reduction of a silicon oxide, purified by acidic precipitation from an aqueous solution of a silicon oxide dissolved in an aqueous phase, using one or more pure carbon sources, the purified silicon oxide being obtained, in particular, by the precipitation of a silicon oxide dissolved in an aqueous phase in an acidifier. The invention also relates to a formulation containing an activator and to a device for producing silicon, a reactor and electrodes.

Abstract: The invention relates to a complete method for producing pure silicon that is suitable for use as solar-grade silicon, comprising the reduction of a purified silicon oxide using one or more pure carbon sources, the purified silicon oxide, which was purified as silicon oxide dissolved in an aqueous phase, having a content of other polyvalent metals or metal oxides, in relation to the silicon oxide, of less than or equal to 300 ppm, preferably less than 100 ppm, especially preferably less than 50 ppm and according to the invention less than 10 ppm of the other metals and being obtained advantageously by gel formation in alkaline conditions. The invention also relates to a formulation containing an activator and to the use of purified silicon oxide together with an activator for producing silicon.

Abstract: The present invention relates to a system for producing silicon, preferably high-purity silicon, particularly solar silicon, and to a method for producing silicon, preferably high-purity silicon, in particular solar silicon, in each case with particularly effective resource utilization and reduced emission of pollutants.

Abstract: The object of the invention is a more energy-efficient system for utilizing waste heat and residual gases from the engineered generation of carbon compounds, such as carbon black, graphite or from sugar pyrolysis, using a coupling of energy-heat or a thermal heat-generating plant for generating electrical energy, in particular for operating melt furnaces, and/or for utilizing the waste heat in endothermal processes. The invention also relates to the use of waste heat.