|GRN Recycle Talk FAQ
Date: Wed, 4 Aug 1999 09:09:26 -0400 (EDT) From: FRIEDMAN.FRED@EPA.GOV (Fred Friedman) Subject: Re: Recycling of plastics, gold and silver (Hans Olsen)
August 4, 1999
Dear Hans Olsen,
Plastics, gold, and silver come from many different waste streams. The particular type of plastic will determine the type of recycling needed. As will the product source. Most plastics require regrinding or repolymerization, and that takes substantial investment. Most gold reclamation takes place from either slag piles or from computer circuit boards, and each can create more pollution than it saves. A chemical bath is necessary for gold reclamation from circuit boards and disposal of the spent chemical is a precondition to environmentally sound reclaiming of gold in this fashion. Similarly with silver, whose most common form of reclamation is from photographic film and chemicals used for photo developing and printing. In the case of silver, good manuals are available from photographic trade associations and from Eastman Kodak in Rochester, NY or from Agfa from its manufacturer in Germany. The US Bureau of Mines (and I'd suspect the counterpart in South Africa) will have technical information on the
reclaiming or claiming of gold from mined slag heaps. The American Plastics Council, as well as international bodies such as ISWA (International Solid Waste Assn.) will be a starting point for recycling plastics. But this literature is huge given the numerous types of plastics and waste streams from which they emanate. There are also many more information sources, and it makes better sense for you to find them domestically than from the US. The key issue in plastics recycling is correctly identifying the material by resin type and avoiding contamination; how you do this again depends upon the waste streams that you are using.
Another good source of info on precious metal recycling which belatedly comes to mind is the Institute of Scrap Recycling Industries, 1325 G St., NW, Suite 1000, Washington, DC 20005.
- Research Library for RCRA