Osram Sylvania Inc.

Raj Pal Singh Gaur

David L Houck

Thomas A Wolfe

Robert G Mendenhall

Michael R Pierce

Scott A Braymiller

A dispensable brazing paste useful in lamp manufacturing includes a brazing powder and a water soluble vehicle that has water, glycerin, a binder, and a dispersant that includes ammonium stearate and ammonium citrate. Preferably, the brazing powder is 84-87 wt % of the paste, the water is 3-5 wt %, the glycerin is 3-4 wt %, the binder is 1-2 wt %, and the dispersant is 4-6 wt %, and a weight of the water is within a range of 60-90% of a weight of the dispersant. The brazing paste does not include the troublesome organic solvents of the prior art.

Dispensible brazing paste

A method for the dissolution and purification of tantalum ore and synthetic concentrates is described. The method preferably uses ammonium bifluoride as the fluoride source in place of the hydrofluoric acid used in the conventional methods. Other fluoride compounds such as NaF, KF, and CaFmay be used alone or in combination with ammonium bifluoride. The tantalum concentrate and fluoride source are combined with sulfuric acid to form a solution containing tantalum values and impurities. The tantalum values are then separated from the impurities by solvent extraction.

Tantalum concentrates dissolution and purification method

An electrochemical displacement-deposition method for making composite metal powders is described. The method is carried out by combining tungsten or molybdenum metal particles with particles of silver oxide or copper oxide in an aqueous hydroxide solution. Heat is applied to the solution to cause the oxide particles to convert to silver or copper metal particles which are substantially adhered to the refractory metal particles. Unlike conventional methods, it is not necessary to heat the oxide powders to a very high temperature in a reducing atmosphere in order to form the composite metal powder.

Growing community of inventors

Athens, PA, United States of America

Raj Pal Singh Gaur