Manufacturers everywhere — and especially metalcasters — have numerous widely used and frequently repeated catchphrases to describe their projects and strategies, terms such as “carbon footprint,” “going green,” “zero discharge,” and “beneficial reuse.” The purpose of these phrases is persuasion: to persuade us of the importance of preserving natural resources for future generations’ use and benefit. Some people adopt this jargon to be fashionable, while others are totally committed to the cause of reducing environmental impacts.
A medium-sized foundry accumulated over 6,200 tons of metal fines from its melting operation, with no place except the dump to dispose of that waste material. Not accepting the dump as an option, a team of foundry engineers began researching other possibilities.
It was at this point that Didion enters the story: A series of tests were conducted to determine the useable metallic content of the waste stream that had been accumulating at the foundry over the previous four years.
The first test was completed, the results tabulated, and the material was returned to the foundry. Not long after receiving the test results and the material, the foundry operators called to request a second test: They couldn’t believe the waste stream had such a high — i.e., valuable — metallic content. Perhaps they had drawn the sample from a rich part of the pile? After a second and third test were completed, confirming the original results, the foundry managers and operators were truly excited by the possibilities of financial recovery, and the anticipated cost savings for their future.
Recovery Strategy
To recover metal fines from their operation’s waste stream, the foundry purchased a Didion® Rotary Separator / Metal Reclaimer with a variable jet burner and a Conveyor Dynamics Feed Conveyor. This system was designed with a dust-tight Load Hopper to be loaded by a front-end loader and metered into the Didion Rotary Separator / Metal Reclaimer. To-date, this un-manned, stand-alone system, installed at a location outside the plant (close to the charging/melt department) has reclaimed over 2,000 tons of valuable metal — material that otherwise would have gone into a landfill as waste, and a lost opportunity for cost savings.
“When we started accumulating the metal fines waste stream four years ago we couldn’t even give it away for free, much less sell it,” according to the foundry’s staff environmental engineer.
“With the addition of the Metal Fines Reclaim System we will continue to recover 1% of metal for every ton of metal melted, permanently increasing our utilization of scrap while taking another step in reaching our company goal of net-zero waste.”
Now, the foundry’s general supervisor refers to that same waste pile as “our bank account.” “The system has proven to be very efficient,” he said recently. “We are one year ahead of schedule in our effort to clean up the site.”