摘要:
To produce valve-metal anodes for electrolytic capacitors, reducing agents are added to the already sintered and/or unsintered anode bodies to improve the electrical properties, whereupon heating is carried out at temperatures above the melting point of the reducing agents and below the temperatures conventionally used for sintering the valve-metal anodes.
摘要:
The invention relates to a process for treating the surface of valve metals, in particular niobium and tantalum, in the form of agglomerated or non-agglomerated powders, thin foils or molded articles prepared from powder, for use as electrolytic capacitor electrodes, these metals being heated in at least one stage to temperatures of 300.degree. to 2,000.degree. C. under a high vacuum or an inert gas atmosphere and in the presence of chalcogens or chalcogen compounds, excluding oxygen.
摘要:
The invention relates to an improvement of the flowability and an increase in the bulk density of high-surface area valve metal powders by means of the addition of finely divided extraneous metal oxides in quantities of up to 5000 ppm, relative to the quantity of metal, before the powder-metallurgical processing of the valve metal powder.
摘要:
The invention describes a method and a device for simultaneously determining the mass, volumes or types of substance samples in a plurality of small cavities (2), particularly of wells in microtiter plates. According to the method, energy is supplied by an energy source (5) to the wells, which are partially or completely filled with samples. Depending on the mass thereof, the samples thus heat up more or less strongly. The determination of the substance volumes in the individual cavities is therefore based on temperature measurement. The simultaneous capturing of the sample temperature in the individual cavities can advantageously be performed by an infrared camera functioning as a detector (6). By implementing suitable calibration and measurement routines in an evaluation unit (7), the entire system, which substantially comprises an energy source and a detector, can be configured such that the substance volumes in the individual cavities are displayed directly.
摘要:
A process for recovering one or more nonradioactive transition metal compounds from an ore containing one or more compounds of said transition metal or metals and further containing at least one complex of a member selected from the group consisting of uranium, thorium, radium, titanium, and rare earth metals, which comprises decomposing said ore in crushed condition by means of an acid so that a portion of the ore is brought into solution in a liquid phase and another portion of the ore remains in a solid phase, said compound or compounds of the transition metal or metals to be recovered passing into only the liquid or into only the solid phase, the uranium in the crushed ore being treated so as to cause substantially all of said uranium to be present in an oxidation state in which it cannot, during the decomposition step, pass into the phase containing the transition metal compound or compounds.