Cellphones and high-definition TVs are not the only technologies making remarkable leaps forward. When it comes to sorting nonferrous metals downstream of an auto shredder, several companies have vastly improved technology.
One such machine from Best Process Solutions (BPS), Brunswick, Ohio, claims it can recover metal pieces as small as 1 millimeter. Called the Recover Max Separator AMS-1600, it sorts auto shredder residue (ASR) into an almost pure lot of copper or another valuable metal.
Tim Conway, president of BPS, says, “It will sort anything larger than 1 millimeter at 99 percent purity.”
The $3 million device, which is designed to process 10 tons per hour, might not be for everyone, but it promises a pay-back within roughly one year, depending on the tonnage processed and the number of hours the machine is in operation. While a smaller shredder probably could not justify the cost of the system, operations set up to handle ASR from a number of regional plants could turn a tidy profit on the machine, according to the manufacturer.
“If you have sufficient quantity, it will pay for itself quickly,” Conway says.
Bill Close of Wendt Corp., headquartered in Buffalo, New York, says that company has a large installed base of optical sensors (using near infrared, or NIR, spectroscopy) in ASR recovery plants. He says, “Our technology has evolved where the optical sensors are now replaced with metal detection sensors (Finders). The Finders are a lower cost to purchase, lower cost to operate and have a higher reliability compared to optical sensors.”
Close adds, “Technology and process are both evolving, allowing fewer machines to solve the same problems. Plants are getting smarter, smaller and lower cost.”
“Sorting for microfines is a huge step in the right direction for recovery of metals out of ASR material that some still consider waste,” says Ryan Njavro, a nonferrous recovery specialist for U.S. Shredder and Castings Group, Miramar Beach, Florida.
He agrees with the others that newer technology can recover ½-inch and smaller material.
BPS, U.S. Shredder and Wendt are not the only companies pushing ASR recovery forward.
“We have unique processes totally different from every other system supplier,” says Marlin Bills, president of Hammermills International, Tulsa, Oklahoma. Unfortunately, he adds, the company is not ready to discuss its technology.
Indeed, this industry segment is moving forward at such speed that some companies are reluctant to talk publicly about the designs they are testing.
Recyclers are undoubtedly hungry for such technology for sorting ASR. BPS says it has demonstrated its new patent pending technology many times and has had more than 50 customer tests at its Brunswick site, near Cleveland. Two installations are underway as of press time.
“You can generate an additional $18 per ton out of outbound ASR,” Conway says of operations using his company’s equipment.
The system has a 75-foot-by-200-foot footprint and screens 12 millimeter material to minus-3-millimeter material at a maximum capacity of 20,000 tons per month, according to BPS.
ECONOMICS OF ASR
“The only thing holding back growth for some at the moment is the market,” Njavro says. He says he sees quite a few people getting ready for the market to rebound, positioning themselves for the upturn. “Others are sitting tight just trying to stay in business,” Njavro says.
In the United States, roughly 9 million tons of ASR are produced each year. After the material goes through a typical screening process, residual ASR is landfilled at a cost ranging from $12 to $35 per ton. Sadly, that includes at least 1 percent copper as well as precious metals—silver, gold and platinum. In addition, ASR also can contain a sizable amount of lead, which, while not a “precious” metal, is certainly a challenge when it comes to landfill leaching and similar problems.
“In all, that is a revenue loss of $165 million,” Conway says.
Maximizing recovery from ASR is just as critical in Europe, where the European Union has increased end-of-life vehicle recovery mandates from 85 percent to 95 percent. While recovering more nonferrous metals may only increase the recovered fraction by a couple of percentage points, it will make it more economical.
In most recycling operations, material smaller than ?-inch, or 12 millimeters, is not processed, sources say. Sometimes, however, it is run across a high-frequency eddy current.
“Purity is key,” Conway says, noting that BPS’ equipment is designed to recover metals from the remaining ASR at a purity of 98 percent or better.
No equipment can perform optimally unless the ASR is first presented properly. “Presentation is 95 percent of separation,” Njavro says. “Vibratory equipment can help the presentation in so many ways.”
He continues, “Aspiration and proper presentation can really help optical sorters perform well in the rough environments we face.
“Air separation is huge,” adds Njavro. “An air plant can be half the size when aspiration is added after sizing.”
In addition to recovering leachable heavy metals, the BPS system produces larger pieces of zorba, according to the company. Zorba is made up of a combination of nonferrous metals, such as copper, aluminum, lead, magnesium, stainless steel, nickel, tin and zinc. A product termed zorba 90 features 90 percent nonferrous metals.
Among the special considerations Close cites to optimize the recovery of nonferrous metals from ASR are consistent shred density and feedstock, uniform flow rates and proper materials preparation.
He says Wendt offers a number of “bolt-on” solutions, such as air classification and product cleanup, that are implemented easily within existing plants, producing minimal disruption.
“We also offer stand-alone processes that can be easily implemented at any time and augment nonferrous recovery and nonferrous sorting operations,” Close says.
BPS says its AMS-1600 produces a high-copper zorba product at refining grade. Conservatively, zorba brings about 58 cents per pound in the mid-2016 market. High-copper zorba can fetch $1.50 per pound when it is recovered from ASR.
The first step with the Recover Max is screening out the 12 millimeter material. (Anything larger than 12 millimeters goes back to the original process.) The second step recovers material ranging in size from 12 millimeters to 4 millimeters, and the third step recovers material smaller than 4 millimeters. The result is a tighter particle size for density sorting.
A zig-zag separator then removes dust and fiber. While this material is probably only 7 percent of the total by weight, it is upward of 30 percent by volume as material cascades down through the air current, BPS says.
By the time the material is sorted to minus 4 millimeters, most of the plastics and wood are gone. The Recover Max takes the resultant material through a magnet to remove any remaining ferrous metal, including iron dirt. At this point, 85 percent of the sort is glass and rock and the remaining 15 percent is metal, according to the company.
The sorted material, red with copper, advances to the polishing step. Light material goes to the wire plant. A minus-3-millimeter sort takes out worthless aluminum and tiny plastic parts. The material appears washed, even though it has not been.
Lastly, an optical sort of the 3 millimeter to 6 millimeter material is completed. What started as a 10-ton-per-hour process is now down to half a ton per hour as material goes through the 30-inch optical sorter, wh
ich produces zorba. Of the 15 percent of the material that goes through the metals process, about 1.5 percent is minus-3-millimeter high-copper zorba, 3 percent of the material is 3 millimeter to 6 millimeter material and 1.7 percent is larger than 6 millimeters.
“You are now shipping value, not waste,” Conway says. The cost per ton averages $23.26, or roughly a penny per pound. With a 15-horsepower motor, the system is energy stingy.
The bottom line is that even a smaller ASR sorting operation can realize $1.67 million income on 1,500 tons of processed material worth $120 per ton. At that point, a recycler remodeling an existing facility might want to push a pencil on the value of installing any system for screening material smaller than 12 millimeters to recover metals.
ON THE DRAWING BOARD
Other corporations have new technology coming off their drawing boards. The question for many recycling operations will be whether it is worthwhile to wait and see if it is an improvement over what is available at the moment.
Among other options recyclers might consider for sorting metals from ASR, Close recommends air separation as a pretreatment to eddy current separators and FOX (Finders, optical, X-ray) sensors to increase recovery efficiencies and to improve product quality. “They are recommended best practices that we implement in our plants,” he says, explaining that air prep is not only good for the equipment and the products produced, it is also good for the scrap yard’s employees because it can create healthier air quality in the plants.
Recyclers will want to consider the overall market before investing in downstream nonferrous recovery technology for their operations. “Plants creating mixed metals packages of zorba, zurik and ASR wire are at risk when China pulls out of the market,” Close says.
At that point, recyclers might want to consider some other solutions to get to base metals in the ASR. These include X-ray systems to convert zorba into aluminum packages, X-ray systems to convert zurik into stainless steel packages or wire chopping systems to convert ASR wire into copper packages.
Even given these new technologies, it still makes sense to pay attention to basics, Njavro says. “Aspiration plays a huge part in separation, cleanliness of the final product and the rate at which separation equipment can process material,” he adds.
Njavro continues, “Buying right is something people need to focus on.”
He emphasizes how important it is to know what is in an operation’s scrap and the yields commonly produced by the material suppliers that systems operators work with regularly.
Regarding the current market, Close says it might be time to diversify an operation’s customer base. “Capitalize on market spreads as they come up and protect yourself when your current customers disappear,” he advises.