Recovery of gold and/or palladium from an iodide-iodine etching

Details Recovery of gold and/or palladium from an iodide-iodine etching Recovery of gold and/or palladium from an iodide-iodine etching

1980-10-03

1982-03-16

Hearn, Brian E.

Specialized metallurgical processes, compositions for use therei

Processes

Free metal or alloy reductant contains magnesium

75118R, 75121, 156642, 156664, C22B 1104, B44C 122

Patent

active

043199232

ABSTRACT:
A method of recovering gold and palladium from a spent aqueous potassium iodide-iodine etching solution, and regenerating the etching solution for reuse, involves adjusting the spent solution to a strongly basic pH (e.g., 12.5) by the addition of an alkaline compound (e.g., potassium hydroxide) to precipitate metallic gold from the solution. Metallic palladium is precipitated from the resulting alkaline solution by the addition of a borohydride, (e.g., potassium borohydride). Following removal of the precipitated gold and palladium, the spent alkaline solution is made acidic-to-neutral in pH to change potassium hypoiodite and some potassium iodide in the solution to iodine. The solution then is adjusted back upward to a slightly alkaline pH value (e.g., 9.0), and precipitate is removed at room temperature. Potassium iodide and iodine crystals then are added to the solution, as necessary, to regenerate the solution to substantially its original composition and strength for reuse.

REFERENCES:
patent: 3390981 (1968-07-01), Hoffman
patent: 3495976 (1970-02-01), Bazilevsky
patent: 3709681 (1973-01-01), Wilson
patent: 3778252 (1973-12-01), Wilson
patent: 3957505 (1976-05-01), Homick
patent: 4190489 (1980-02-01), Bahl
patent: 4260451 (1981-04-01), Schmeckenbecker
Western Electric Technical Digest, No. 45, Jan. 1977, pp. 22, 23.
IBM Technical Disclosure Bulletin, vol. 18, No. 2, Jul. 1975, p. 413.

Affiliated with

Also associated with

Rating

Recovery of gold and/or palladium from an iodide-iodine etching does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Recovery of gold and/or palladium from an iodide-iodine etching , we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Recovery of gold and/or palladium from an iodide-iodine etching will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-1640296