Degussa Aktiengesellschaft

Roland Gerner

Wolfgang Weber

Hans-Hermann Beyer

Klaus Zimmermann

Karlheinz Kleiss

Dieter Hollmann

Wear-resistant hard material layers are prepared on a metal support by applying onto said support a mixture of hard material particles, solder particles and organic binding agents and thereafter soldering the layer by heating. The mixture thus obtained can be applied by means of immersing, screen printing, brushing, spraying or spreading. The stable suspension required for the above steps is prepared by homogeneously grinding the particles together to a particle size from 1 to 20 .mu.m and adding an organic solvent to the binding agent.

Process for the preparation of wear-resistant hard material layers on

A process for the separation of rhodium from rhodium containing organic solutions, organic-aqueous mixtures or aqueous solutions containing complexing agents is disclosed. Metallic bismuth, bismuth oxide, bismuth hydroxide or another reducible bismuth compound is added to 50.degree. to 250.degree. C. as a precipitating agent, optionally with a reducing agent, and the precipitate is separated. The corresponding antimony compounds can also be used in place of bismuth.

Process for the separation of rhodium from organic solutions

In order to produce dustfree silver nitrate which can be readily dosed, silver nitrate is atomized in a molten state. A purity of the silver nitrate of greater than 99%, a pH of 2 to 6, and the exclusion of light during the atomizing are necessary.

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Rodenbach, Germany

Roland Gerner