Interstate Shredding is located on a 28-acre facility in Girard, Ohio and is an operation that dates back to the 1950s. In 2008 the new owners upgraded the facility’s entire infrastructure with the goal of increasing profitability.
Interstate collects, processes, recycles, trades and brokers metal, both ferrous and nonferrous. The metal is purchased from industrial manufacturers, auto salvage facilities and metal dealers, and generally comes from obsolete machinery and equipment – mostly autos and home appliances.
One of the earlier upgrades at Interstate was with the installation of a Metso/Texas 85x104 automobile shredder, a unit with the capacity of shredding 10,000 to 15,000 tons of scrap per month. The company also purchased their first electric-powered material handler, in early 2009 – an electric-powered Sennebogen pedestal mounted 835 C Series machine, which was specifically designed to feed their shredder.
“This was a totally new operation from the ground up, even though we transformed another existing scrap facility on this site,” says Interstate Co-President, Michael Clayman. “Every piece of equipment is brand new and we are creating ways to get more revenue by pulling out more metal from scrap and not sending it to the landfill.”
Along with their new Metso/Texas shredder and electric-powered Sennebogen material handler, Interstate has invested heavily in separation equipment right from the start by purchasing ProSort and FinesSort metal recovery systems, as well as drum magnets, pulley magnets and eddy current separators, all from Pennsylvania-based Eriez Magnetics.
“Our parent company, Liberty Iron and Metal, has used Eriez equipment for many years and it was through their positive experience that we considered installing Eriez metal separation products at the Interstate facility,” Clayman explains. “We met with Eriez and they helped us determine the best equipment for what we were trying to accomplish.”
A system-wide approach
Once scrap metal arrives at Interstate, it is processed by sorting, shredding, torching and baling. The company says their Metso/Texas 85 x 104 shredder can reduce auto bodies, home appliances and other metal into fist-sized pieces. (85 x 104 refers to the size of the outstretched hammer diameter multiplied by the nominal rotor width.)
Shredded material is then carried by conveyor under Eriez’ magnetic drums which attract the ferrous metals and separate them from the nonferrous metals. Dual 60-inch x 96-inch electro agitating drums are set at an 11-inch gap and pull ferrous metals from the edges, resulting in better metal recovery and cleaner frag. The remaining shredded pieces head downstream for further separation.
Next, a set of 24-inch x 48-inch Eriez AIP magnetic pulleys capture additional ferrous metals after the magnetic drums, such as crankshaft journals and larger chunks of iron. The separation process continues when remaining ferrous works its way through a set of 18-inch x 36-inch AIP Pulleys, which capture smaller ferrous, including wires and small clumps of magnetic fuzz.
According to Eriez, operation of the AIP magnetic pulley is relatively simple. They are used as head pulleys on Interstate Shredding’s belt conveyors. As the scrap metal comes within the pulley’s magnetic field, the ferrous scrap is attracted and held to the belt until it reaches the underside, passes out of the magnetic field and is separately discharged.
The recovery process continues when post magnetic pulley automobile shredder residue (ASR) passes through twin 60-inch Eriez Xtreme eddy current separators which further separate out nonferrous metals.
ProSort and FinesSort
Using magnetic drums, pulley magnets and eddy current separators to separate larger pieces of scrap metal for re-sale is enough for some salvage facilities, but according to Eriez, operations such as Interstate are taking total metal recovery to the next level, by installing their ProSort and FinesSort metal recovery systems from the start.
“After magnetic drums, you’ll typically have a screen that will split product by size,” explains Darrel Milton, the Canadian sales manager for Eriez Magnetics. “With our system, the fine material, which is typically minus 1-inch to minus 1-1/4-inch will go to the FinesSort, which is essentially a specialized, high-grade eddy current separator. Two products are created, ferrous and nonferrous, in two stages. Then the oversize (1-inch to 1-1/4 inch) goes to an eddy current separator. The fluff from the eddy current goes to the ProSort, which is a single-stage airless separator – essentially a scavenging device.”
“When you’re talking fine material, say minus 1-1/4, it accounts sometimes for about 50 percent of the weight of fluff, and in there, there could be 10 to 15 percent metals (potentially),” continues Milton. “After the eddy current separator you’re going to lose about five percent. The ProSort is designed to capture that five percent.”
“With the FinesSort, when people see material going in, it looks like a big compost pile, and you run your hands through it and can’t find a piece of metal anywhere. Then it’s run through the machine and it starts spitting out all this nonferrous.”
At the Interstate facility, their ProSort and FinesSort systems are definitely making a significant difference. Any metal missed by the eddy current separators travels by conveyor belt to a 90-inch wide ProSort metal recovery system that recovers the majority of nonferrous and stainless steel greater than one inch.
As opposed to traditional air-based separation, the ProSort airless system uses high-sensitivity metal sensors aligned with low energy electromagnetically driven paddles to separate valuable metals from waste material. According to Eriez, by replacing expensive air compressor plants, valves and airlines with energy efficient electromagnetic drives, the ProSort recovery system requires less than 25 percent of the electricity needed to operate an air-powered sorter.
For Interstate, this lower cost of operation was an important consideration, since each ton of nonferrous recovered by their ProSort goes to the company’s bottom line.
Prior to the ProSort and eddy current separators, Interstate’s minus one inch fines are screened out and conveyed to a 60-inch wide FinesSort metal recovery system, which recovers the small ferrous and nonferrous metals. Three product streams are created at this stage: a clean ferrous stream, nonferrous metals – typically Zorba 95 – and a waste stream.
The ferrous stream is first separated using a powerful Rare Earth Pulley that pulls the ferrous material out. An adjustable gap magnetic drum further separates the saleable ferrous materials from residual waste that is entangled with the ferrous. The clean ferrous is dropped onto a cross conveyor and into a collection bin and the waste onto a waste conveyor.
The second stage reclaims the valuable nonferrous metals. A special high speed eddy current separator repels fine nonferrous metals and the waste drops onto a waste conveyor. The recovered nonferrous then drops onto a cross conveyor and from there into collection bins. One additional benefit of the ProSort is that it is engineered to operate efficiently in cold weather conditions. This is important for operations such as Interstate, with its location in Northeast Ohio.
According to Milton, there are two installations in Canada that are using FinesSort and ProSort machines in a similar way to Interstate (Steel Pacific in Victoria, B.C. and Glenview Iron & Metal in Smith Falls, Ontario.)
“If you look at our ProSort machine in Smith Falls, in the Ottawa region, it sits out in the elements all year,” says Milton. “It doesn’t even have a cover on it.” “Because it doesn’t operate with air, but with our electromagnetic paddles, there are no airlines to freeze up. The electromagnetic paddles are oblivious to the weather.”
Exceeded expectations
Interstate’s Gary Clayman says their new equipment has exceeded expectations at their facility. “Everything is as represented when we bought the Eriez system,” says Interstate’s Gary Clayman. “We’ve been very pleased with the products during our start-up phase and beyond. The frag is exceptionally clean, as is the aluminum, and there is very little metal – if any – in the shredder fluff.”
Gary’s brother, Michael Clayman adds, “The Eriez equipment, especially the ProSort and FinesSort, is capturing metals that used to end up in landfills. Now we have more valuable metals to sell to our primary markets: foundries and steel mills. ProSort and FinesSort are like pennies from heaven.”
