March/April 2006
Briquetters and puckers add value to turnings, chips, and other loose scrap while recovering fluids, easing material handling, and doing much more.
By Lynn R. Novelli
Looking for a more efficient, more profitable way to manage metal turnings and chips? If so, there could be a briquetter or pucker in your future.
The scrap industry uses those machines mainly to compress metal chips, turnings, fines, and other loose, bulky material into dense, dry briquettes or pucks. The process, which dates back 158 years, offers various financial, environmental, safety, handling, and transportation advantages to every party in the scrap chain—generators, processors, and consumers.
Could this equipment enhance your operations? This review can help you decide.
Briquetter Basics
There are two general types of briquetters and puckers:
- rotary cylinder models, which compact material between two rotating cylinders indented with molds—also called tooling—that capture it and compress it into a briquette shape; and
- hydraulic press models, which use a hydraulic ram to compress material into hockey puck-shaped rounds, rectangles, or cylinders.
Briquetters and puckers come in many sizes and prices, from a $55,000 machine with a 5-foot by 6-foot base suitable for a small machine shop to a 15-foot by 20-foot, $350,000 machine that can handle cast iron scrap at a foundry. Note that these machines are usually part of a total scrap management system that can include an infeed conveyor, fluid collection system, crusher/shredder, and take-away conveyor.
The equipment’s processing capacity varies based on the material being compacted and the unit’s size. A small machine can compress 200 pounds of ferrous or 100 pounds of aluminum scrap an hour. Larger briquetters can process 2,240 pounds of ferrous or 1,100 pounds of aluminum an hour. Briquetters can process just about any metal scrap, and manufacturers will customize their machines as needed to accommodate specific metals.
With computer controls, today’s state-of-the-art briquetters can operate virtually unattended. Labor requirements are estimated at about 30 percent of a single employee’s time, which means that one operator can run multiple briquetters in a large operation. Even loading is automated in systems that include an infeed conveyor or gravity-feed device that dumps scrap into the hopper from above. Users can program these machines to start operation when the precharge chamber is full.
Reviewing the Benefits
Dollars and Sense: A key reason to briquette or puck material is to increase its value. In fact, William Easby invented the briquetting process in 1848 specifically to add value to fine coal. His rationale for developing the process for coal still holds true for loose turnings and similar scrap metal: “by this process an article of small value and almost worthless can be converted into a valuable article.”
Today, this value-added practice benefits scrap generators, processors, and consumers. For instance, one scrap generator—a major manufacturer of aircraft components—was getting 6 cents a pound for its loose aluminum chips. The firm installed a pucker, and it now sells the same material as pucks for 48 cents a pound.
In turn, scrap processors can sell briquetted material to foundries and steel mills at higher—and, reportedly, less volatile—prices than loose material. Mills and foundries pay more for briquettes and pucks because of the material’s density, hence its higher yield in the melt. The compacted material offers an 80 percent to 90 percent metal yield compared with 40 percent for loose material, sources note.
“Put chips into the hot metal and they’ll disintegrate or fly into the baghouse and tear it,” explains a briquetting expert. “Turnings float to the top and end up in the slag line. Pucks and briquettes are heavier, so they sink to the bottom of the melt, melt slowly, and mix in.”
Storage and Shipping Savings: Briquetters and puckers also offer huge advantages in terms of storage, handling, and transportation.
A briquetter, for instance, can reduce the volume of chips up to eightfold. That means a briquetter could compress eight 55-gallon drums of chips into a single drum of briquettes. That condensed shape and volume makes briquettes less expensive and easier to store than chips. Briquettes simply take up less floor space and store neatly in drums, stacks, or cartons. They are also much easier to handle than bushy material.
When it’s time to ship briquettes or pucks, processors can load them into a railcar or trailer more easily and more efficiently than they can load loose material thanks to their compact, uniform size. According to one briquetter manufacturer, a trailer can hold 40,000 pounds of briquettes or pucks—much more than the maximum shipping weight for a load of unprocessed chips. With transportation costs soaring, that difference can mean sizable savings for the shipper.
Environmental Pluses: Briquetting also gives scrap generators, processors, and consumers a leg up on environmental issues. During the compacting process, most of the cutting fluid in the chips is squeezed out and recovered. Manufacturers claim that their machines can recover 95 percent to 98 percent of the fluid in chips. That’s important considering that loose aluminum chips can reportedly hold 20 percent to 30 percent of their weight in fluid, and other metals can hold about 10 percent. Eliminating that moisture vastly improves the scrap’s quality.
Recovering fluid from metalworking scrap has many benefits:
- Operators often can filter the fluid and use it again, eliminating the need for and cost of new fluid.
- The fluid no longer poses environmental risks during storage or transportation of the scrap, and operators avoid the potential liability exposure of storing or transporting loose, wet material.
- The fluid no longer creates slick floors in the workplace, thus it doesn’t present a slip-and-fall hazard and related liability issues.
- Recyclers can avoid deductions for fluid contamination of material.
- For mills and foundries, dry briquettes and pucks mean fewer production problems related to moisture in the melt.
According to several equipment manufacturers, U.S. EPA is paying more attention to fluid recovery, which is boosting the demand for briquetters. “For example, if EPA requires machine shops to account for 80 percent of the cutting oil they purchase, or 80 out of every 100 gallons, briquetting can recover almost all of that fluid,” a briquetter technical specialist says. “When the recovered fluid is filtered, about one-third of it can be reused. This satisfies the EPA regulations and reduces production costs for cutting fluids by one-third.”
For scrap processors, the above points simply mean that “briquettes and pucks are hands-down more profitable and easier to manage than chips,” says the president of one of the largest metal recycling companies in the United States. And he should know—his company operates more than a dozen briquetters at various locations.
Managing Scrap
Though some foundries and steel mills run their own briquetters to close the loop in their plants, others purchase processed briquettes and pucks from scrap recyclers. Some of the largest scrap processors have briquetters in their yards, but it’s more common for processors to purchase a machine and install it at a scrap generator’s operation. In return, the generator signs a long-term scrap management contract with the processor. The generator provides the manpower and electricity to operate the equipment, and the processor picks up, transports, and sells the pucks or briquettes.
Installing a briquetter or pucker at the generator’s location can help ensure the quality and consistency of the scrap that’s generated. That’s important because briquettes and pucks command the highest price when they contain a consistent grade and chemistry of material. Scrap consumers need to know what they’re getting so they can add the material to their melting mix without a lot of analysis.
This means that large scrap-generating operations that produce one grade of material are ideal environments for briquetting. “The grade of material going into the pucker or briquetter is controlled at the source, so the final product is uniform and of known composition,” a technical expert says.
Scrap processors that handle different grades of loose turnings or chips on their own premises have a bigger challenge. It’s possible to briquette mixed grades of a single metal, though such products command a lower price than pure-grade briquettes.
Factors to Consider
The basic concept of briquetting is universal—load material, compact it, collect the cutting fluid, and discharge a briquette—but there are some differentiating features to look for when purchasing a machine.
For rotary cylinder models, the pressure exerted at the face plate during compacting is one of the most important features. “The density of the finished pucks or briquettes determines their quality and price, and the face pressure during compacting is what determines briquette density,” says a spokesperson for one manufacturer. “The higher the face pressure, the denser the briquette and the better the quality.”
The number of moving parts in the compression chamber is another consideration that relates to the machine’s service life. Briquetters are simple, hard-working machines, and fewer moving parts usually means less wear and longer machine life.
In rotary cylinder machines, it’s important to protect the molds, or tooling, in the cylinders from foreign objects or oversized pieces, as replacements can cost $2,000 to $10,000. With normal use and proper maintenance, though, the tooling should require replacement only once or twice a year, depending on the number of cycles and the material being compacted. The manufacturer can estimate the life of the tooling for specific applications.
Though hydraulic press machines have a lower initial cost than rotary cylinder models, the hydraulics require monitoring because of the high pressure they exert during compression. “Triple-lock O fittings will help prevent leakage, but no system can guarantee totally leak-free operation,” says a spokesperson for a manufacturer of hydraulic press briquetters. When considering a purchase, she suggests making sure that any hydraulics on the machine have a built-in containment system to capture leaking fluids.
For machines that work this hard, proper maintenance is essential to prevent costly repair bills. For optimal performance, users must change the oil, filter, and cooling fluid regularly. Manufacturers also recommend a regular maintenance schedule for hoses, set screws, and hydraulic filters, both to determine if these components need replacing and to make sure they remain secure during operation. The vibratory nature of the compacting process tends to loosen these parts, which detracts from operating efficiency and causes a safety hazard.
Overall, sources note, expect to spend $3,000 to $5,000 annually for maintenance on a briquetter or pucker, not including replacement costs for the tooling. Machine components, with the exception of the cylinders, usually are under warranty for a year or a specified number of cycles.
Determining ROI
In theory, briquetting sounds like a sure-win proposition. In truth, it’s not for everyone, says the president of a small briquetter manufacturer. “The most common mistake people make is not researching the market demand for briquettes in their area,” he says. “These machines are a big investment, so you have to think the whole process through very carefully to determine your return on investment.”
He advises potential buyers to evaluate the purchase price of the equipment, the volume of scrap being generated for briquetting, the labor and energy costs, and the savings from fluid recovery.
The most important point, he says, is to know your market. Most briquetters are in the Midwest, on the West Coast, and in certain areas of the South, where steel mills and foundries are concentrated. “Briquettes are a great product—but only if you have a buyer,” he says.
To assist companies in their equipment purchasing decision, most manufacturers will run a trial load of the customer’s scrap through their briquetter or pucker to make sure the resulting product meets expectations.
Some briquetter and pucker manufacturers will also ship a load of sample briquettes to the potential equipment buyer. The buyer can then explore the market potential of these samples in the area and evaluate the return on investment before buying the equipment.
Like any capital equipment purchase, buying a briquetter or pucker ultimately comes down to cost and payback. The good news, the small briquetter maker says, is that with the right combination of scrap volume and market, it’s possible to realize a return on investment with briquetting equipment in less than six months.
Lynn R. Novelli is a writer based in Russell, Ohio.
Briquetters and puckers add value to turnings, chips, and other loose scrap while recovering fluids, easing material handling, and doing much more.