摘要:
A method for recovering high grade gold alloy in an unoxidized condition from karat gold clad to a base metal substrate without significant oxidation of the substrate, wherein the substrate is employed as an anode in an aqueous solution of from about 0.02 to about 2% by weight nitric acid and is subjected to electrolysis at a temperature of from about 48.degree. C. to about 94.degree. C. for sufficient time to delaminate karat gold from the substrate in particulate form and deposit same in the solution, from which the delaminated karat gold may be separated. Also disclosed is an apparatus suitable for carrying out such process, comprising an electrolysis tank wherein the karat gold-clad base metal substrate is mounted in spaced relationship to a cathode, with filtration means disposed in the tank for collection of delaminated karat gold formed during the electrolysis, and means for draining or otherwise withdrawing electrolyte solution from the tank after termination of the electrolysis conditions, whereby the delaminated karat gold may be recovered from the electrolyte solution.
摘要:
A gold based alloy containing gold, silver, copper, zinc, silicon, iron, boron, nickel and indium for the manufacture of gold articles is described which has a lower melting point, extended remelting capabilities, high resistance to cracking, improved color consistency and increased ductility.
摘要:
An indium-free, gold-colored, tarnish and corrosion-resistant alloy having no greater than 10% by weight gold and a color value, as measured according to the Cielab Color Measurement System, of approximately L=87.4, a=1.1, b=15.3. The alloy comprises 28-35% copper, 19.5-22.5% silver, 6-11% palladium, 22-32% zinc, 0.1-1% aluminum, and 0.5-3% platinum.
摘要:
A strip of silver-copper brazing alloy, connected to the positive terminal of a rectifier, is passed through an acid treatment bath containing a cathode adjacent each face of the strip. The strip is resistively heated to a temperature of at least 350.degree. C. prior to its entry into the treatment bath by passing an electric current through the strip and the treatment bath to the cathodes. Copper oxide is electrolytically dissolved from the surface of the strip in the treatment bath.