Aluminum Recycling Breakthrough Means Potential Boon for Automakers; Laser Separates Aluminum by Alloy, Increases Scrap Value
25 October 2000
Aluminum Recycling Breakthrough Means Potential Boon for Automakers; Laser Separates Aluminum by Alloy, Increases Scrap Value
DETROIT, Oct. 25 A new recycling process using advanced
lasers to improve automotive scrap sorting can help bring even more
environmentally friendly cars and trucks to market, according to an
announcement today by the auto and aluminum industries, made through their
Auto Aluminum Alliance, in conjunction with the U.S. Department of Energy.
By employing lasers to identify and recover metals from scrapped vehicles,
researchers have demonstrated the ability to separate cast from wrought
alloys, as well as the ability to separate wrought alloys from each other at
commercially viable rates.
The announcement is a potential boon to automakers and suppliers since
this advanced recycling process promises to improve economic efficiency by
recovering greater quantities of high value, high strength, high performance
aluminum from scrapped motor vehicles. Ultimately, this will allow greater
use of either recycled or primary automotive aluminum -- which weigh
significantly less than steel -- and will help produce even more
environmentally friendly autos since lighter vehicles get higher gas mileage
and emit fewer emissions.
For the 2001 model year, aluminum passed plastics and became the third
most-used material in cars and trucks. Nearly ninety percent of automotive
aluminum today is recovered and recycled. While this aluminum represents less
than 10 percent of the average motor vehicle by weight, it already accounts
for roughly half of the vehicle's value as scrap.
"The techniques we're exploring will allow us to recapture more of the
value and performance capability of the many high quality aluminum alloys that
are used in our vehicles. Current separating techniques only allow us to
separate aluminum from other materials in scrapped vehicles. The recovered
aluminum is then recycled into castings. But the new techniques will enable
us to separate cast aluminum from wrought and even differentiate between
wrought alloys," said Jim Quinn, staff engineer, General Motors Corporation
and Chairman of the U.S. Automotive Partnership, Automotive Metals, United
States Council for Automotive Research (USCAR).
"Each year, automakers are using greater amounts of aluminum to help boost
fuel economy and performance while maintaining safety. This advanced scrap
sorting process will help ensure that automakers have a more affordable supply
of recycled aluminum for the future. It also shows the great strides that can
occur when the auto, the aluminum and the scrap industries work together to
solve technical challenges," added Dr. Richard Klimisch, Vice President of The
Aluminum Association.
This advanced method of separating scrap materials is being evaluated by a
Belleville, Mich. metals processing firm, Huron Valley Steel Corporation. The
Auto Aluminum Alliance is working with Huron Valley as part of a one-year
agreement launched
August 24.
Using a sophisticated technique called Laser Induced Breakdown
Spectroscopy (LIBS), the new process uses a laser to first clean the surface
of the particle by laser ablation, and then it employs a laser pulse to hit
the same spot on the particle as it moves down a conveyer belt. This second
laser pulse vaporizes a small amount of material from the metal's surface
creating a small, highly luminescent plume of plasma, or ionized gas. To
quantitatively determine the metal's chemical makeup, the plume is then
analyzed by a technique called optical emission spectroscopy. Once the
verification is made, the scrap is sorted by alloy on a piece-by-piece basis.
This breakthrough process is significant because it provides a practical
way of sorting the scrap at commercially viable rates. Up to now, such alloys
were sorted manually, which is a slow and costly process. It is estimated
that the first commercial sorting center will be able to analyze and sort 100
million pounds of aluminum per year.
Increasing the efficiency of recycling aluminum does more than add value
to recycling aluminum for automakers, it also reduces energy consumption. The
production of recycled aluminum requires just five percent of the energy
needed to produce primary materials.
The Auto Aluminum Alliance is an inter-industry collaborative research
effort between USCAR and The Aluminum Association, Inc., and it is reviewing
technical projects to further accelerate the use of new and improved aluminum
technologies for motor vehicles.
USCAR is the umbrella organization of DaimlerChrysler, Ford and General
Motors, formed in 1992 to further strengthen the technology base of the
domestic auto industry through cooperative, pre-competitive research, carried
out in conjunction with the U.S. Department of Energy.
The Aluminum Association, based in Washington, D.C. with offices in
Detroit, Mich., represents primary producers of aluminum, recyclers and
producers of semi-fabricated products. Member companies operate almost 200
plants in 37 states.