Sustainability Gets the Green Light
The metalcasting industry sees itself as a leader in recycling. But when it comes to engaging local government, communities and customers, metalcasters can improve their message of waste reduction and beneficial reuse.
Nicholas Leider, Associate Editor
(Click here to see the story as it appears in June's Modern Casting.)
Many in the metalcasting industry refer to themselves as “the world’s original recycler.” The saying is perfect for a bumper sticker, but metalcasters have a problem when it comes to a deeper discussion of environmentally sustainable practices. The industry is conscious of reducing wastes, reducing costs and fulfilling a vital role in industrial sustainability, but such efforts often fall on deaf ears of local communities, government officials and customers.
Because a reduction in waste or decrease in consumption is financially beneficial does not make it any less environmentally friendly. Metalcasters need to be aware that successfully implementing sustainability programs can make economic sense and also improve relations with their neighbors. Fortunately, metalcasting has a number of inherent positives in regards to sustainability, which is a great way to begin a conversation on the topic of going green.
“There isn’t another industry, in terms of raw materials, that recycles as much as we do,” said Mike Lenahan, CEO of Resource Recovery Corporation, Coopersville, Mich., and president of AFS-FIRST (Foundry Industry Recycling Starts Today). “Look at the national average for household recycling. The numbers are between 22-30%. In addition to recycling foundry sand within the casting process, a foundry with a strong beneficial use program may be recycling as much as 95% of its discarded sands and slags. That’s incredible.
“On top of that, guess what they’re consuming as feed stock? They’re accepting somebody’s old washing machine or a 20-year-old engine block that’s otherwise useless and turning it into something brand new.”
In addition to conversations with the surrounding community and local government, customers are beginning to ask suppliers about sustainability and corporate responsibility, and metalcasters, if they aren’t already, will need to prepare an answer.
Buyers want to know a supplier’s plan to thrive for the foreseeable future. It’s about risk management—the supply chain won’t break when a metalcaster operates as expected.
Making the Most of Metal
The metalcasting industry reuses huge amounts of scrap from other manufacturing industries. Other manufacturing processes, like stamping, forging and machining, can produce usable scrap. Additionally, when a metal component reaches the end of its life, it can be scrapped and reused. The environmental benefits and reduced pressure on landfills are obvious. Metalcasters use what otherwise would be unwanted leftover material, which reduces a casting’s final cost.
“You’d raise the price of the casting by 20-40% if you weren’t able to utilize the recycled material,” said Gene Muratore, metalcasting industry consultant. “Whatever you pay for those raw materials will affect the price of what you’re selling.”
According to the U.S. Environmental Protection Agency, recycling steel reduces air pollution by 86%, water use by 40%, water pollution by 97% and mining wastes by 97% in comparison to using virgin iron. Additionally, using scrap metal requires less energy, which can mean additional savings for a metalcasting operation.
Internally, all gates, risers and runner bars will be separated from the casting before it’s ready to be shipped. Approximately 1% of metal will be lost during the melting process in dross and slag. Depending on the casting, machining also may result in metal loss. But for the large majority of casting operations, somewhere in the neighborhood of 95% of the as-cast part will eventually exit the metalcasting facility as the finished casting.
Costs are involved in processing and reusing metal, but the overall efficiency of the operation means waste remains relatively small. Additionally, the castings that exit a metalcasting facility could potentially become scrap that may head to another metalcasting facility for a second or third life.
“Metal doesn’t have a memory,” said Geoffrey Sigworth, GKS Engineering, Dunedin, Fla. “It doesn’t know or care it was a casting yesterday.”
Reclaiming and Reusing Sand
Foundry sand, which is used by 60% of metalcasters for molds and cores, represents a significant industrial byproduct. Due to increasing regulatory control and disposal costs in the last 30 years, metalcasters have reduced the amount of sand headed to landfills.
The industry discards between 5-8 million tons of sand annually. However, according to a recent industry study, prior to being discarded, the average sand grain is reclaimed and reused by the metalcaster an average of eight times.
Additionally, approximately 30% of foundry sands are reused in non-landfill applications, including geotechnical fills, road sub-base, embankment construction and soil additives. Despite the advancement of recycling initiatives, it is not necessarily a revenue-generating endeavor. Processing costs to get the material to “product quality” typically consume any margin in the sale price. However, beneficial reuse minimizes disposal costs and produces environmental benefits—a win-win for the metalcaster and its community.
For an industry with a significant number of small facilities, metalcasters should engage government officials and community leaders to explore possible beneficial reuse programs. Bryant Esch, environmental coordinator, Waupaca Foundry Inc., Waupaca, Wis., encourages dialogue between metalcasting facilities and the local community and government.
“Everyone should interact with their state regulators. Have a discussion—this is what we have, this is what we want to do,” Esch said. “Start with smaller projects to get you going. Each foundry needs to pick projects that are feasible. Whether it’s a project with the local community that is great PR, whether it’s a small project that allows you to start beneficial reuse, you need to pick the project that works for you. And, as you’re doing it, make sure to stay focused on project management.”
According to EPA estimates, beneficial use of discarded sand is saving more than 202 billion BTUs per year and reducing CO2 emissions by 20,000 tons. EPA has determined a vast majority of foundry sands are considered non-hazardous solid wastes. Individual states, however, retain regulatory authority over the materials, even when they are comparable in physical and chemical nature to non-regulated materials.
“We’ve run into regulatory challenges, but we’ve made progress,” Lenahan said. “Everybody is into green initiatives. The timing is right for the use of recycled sand to be accepted. I think people are more receptive to using material, but also our industry has gotten better at marketing the material.”
Regulations can prove cumbersome, but the general public has become more amendable to reusing an industrial byproduct. When engaging potential partners, metalcasters are beginning to emphasize the uniformity of discarded sand and its tightly controlled properties.
Energy: The Next Frontier?
Unlike the industry’s highly optimized recycling processes with metal and sand, improved energy efficiency remains in the early stages of development for many metalcasters. Progress in this area can reduce waste and cost, which bolsters a metalcaster’s overall message of corporate responsibility.
One trend that is beginning to take hold in the industry is waste heat recovery. For example, a facility’s engineers can modify the melting system to more efficiently use waste heat. If heat from a furnace otherwise escapes without purpose, it can be used to preheat the material for the next charge.
Historically, metalcasting facilities have received a single utility bill for electricity or gas usage. But specialized measuring systems are becoming more prevalent in the industry. Energy experts have developed sub-metering practices that measure consumption on specific pieces of equipment, allowing metalcasters to see exactly where energy is used.
Brian Reinke, an energy consultant with TDI Energy Solutions, Lemont, Ill., sees process improvement as another area of potential savings. For example, improving training procedures for those operating furnaces, aircompressors and dust collectors, can lead to reductions in energy consumption.
“This is something we run into constantly,” he said. “Inconsistent operations and insufficient training can be very costly, but largely hidden in day-to-day operations. Once discovered, they can be easily addressed.”
Additionally, programs are available to provide energy audits of manufacturing facilities. Energy consultants evaluate an entire operation, and many state and local governments and universities offer audit programs. Industry trade groups, including AFS, offer audits specific to the metalcasting industry.
Considering the growing emphasis on increasing efficiency and reducing waste, the general public is becoming more receptive to smart, safe uses of industrial byproducts. Still, metalcasters can actively work to ease remaining skepticism from community leaders and government officials.
“There is an up swell of desire to reuse industrial products, but you still are fighting perceptions of people who don’t understand,” Esch said. “The kneejerk reaction can be negative and that’s why getting involved with your community is so important. Communication is vital. Once the community is informed, they can be really receptive.”