N.D. company turns coal byproduct into jobs
article provided by Minnkota Power Cooperative
Each day at Abrasives, Inc., workers are turning waste into worth.
The North Dakota company takes one of the byproducts of coal combustion – bottom ash, also known as slag – and gives it new life in the form of sandblasting media, roofing granules and “sand” for golf course bunkers.
All of the coal combustion residuals (CCRs) processed at Abrasives’ Glen Ullin facility come from Minnkota Power Cooperative’s Milton R. Young Station. Abrasives operates a fleet of trucks between the plant and Glen Ullin, transporting bottom ash for screening and grading.
Rather than Minnkota disposing of these inert CCRs in a landfill, Abrasives recycles them into Black Magic, a truly “green” product that conforms to environmental and safety standards. The materials are low-dusting, chemically inert and have low free silica content.
“We’re taking what would otherwise be considered a waste product and recycling it,” said Abrasives President Russell Raad. “By taking the coal byproduct and reusing it, we’re able to put a highly effective, environmentally compatible product into the marketplace.”
The core product is a sandblasting media that is used to remove surface coatings such as rust or paint. It is primarily applied to bridges, oil field equipment, rail cars and machinery that require cleaning or coating.
Black Magic is also used for roofing granules, including headlap, backsurfacing and mineral surfacing granules. Abrasives has even found a niche in the golf world. Black Magic bunker slag gives several area courses, including Bismarck’s Hawktree Golf Course, a distinct, stylish black “sand” bunker.
“There is such a wide variety of uses for the product, and we’re seeing an increase in demand,” Raad said.
The company has rail access to deliver large quantities anywhere in the United States or Canada. At peak production times, Abrasives has about 20 employees on site.
The Young Station uses about 4.3 million tons of lignite coal each year, resulting in 340,000 tons of coal ash. Approximately half of the ash produced is bottom ash. Of that, Abrasives purchases roughly 100,000 tons per year.
“The product that we get from Minnkota is better than what our competitors receive,” Raad said. “The difference in the coal is a big part of it, but it’s also how the coal is burned. The mixture of North Dakota lignite and the cyclone-fired burners makes for a very hard product.”
Bottom ash that Abrasives does not purchase is beneficially used on site by Minnkota (for dust control in landfills, pipe bedding material and drain applications in landfill construction) and by BNI Coal, the plant’s coal provider, on muddy roads. Several thousand tons each year are also donated to state and county road departments for ice control during the winter.
“It’s important to reuse an inert coal combustion byproduct like boiler slag from a cyclone boiler,” said Craig Bleth, Minnkota plant environmental superintendent. “It has value, has many potential uses and it should be reused. It is particularly good when a local company can provide a value-added product, and in the process employ a local workforce to do it.”
The coal combustion process also produces fly ash, which is collected from the flue gas by electrostatic precipitators that are installed on both units. The fly ash is collected in hoppers and trucked to permitted landfills by plant personnel. Fly ash was formerly used as a reagent in the Young 2 scrubber; however, it is no longer used for that purpose.
The recycling and beneficial reuse of coal ash has been a great success for utilities throughout North Dakota. Even when it is not able to be recycled, coal ash is disposed of in landfills permitted and monitored by the North Dakota Department of Health.
Despite environmental benefits and sound management by utilities and state officials, the Environmental Protection Agency (EPA) is considering two new options for coal ash management, including one that would treat it as a hazardous waste for the first time.
Under Subtitle C of the Resource Conservation and Recovery Act (RCRA), CCRs would be designated as hazardous waste and subjected to federal hazardous waste management requirements. This would be a costly proposal for utilities and ratepayers and could also cause irreparable damage to coal ash recycling efforts.
“It’s something that could potentially shut us down,” Raad said.
The other option the EPA is considering is Subtitle D, which would designate coal ash as nonhazardous solid waste. This option is similar to requirements currently in place in the state of North Dakota.
On four prior occasions the EPA has determined that coal ash does not warrant the hazardous designation. The agency is expected to issue a ruling within two years.
“Regulating CCRs as a hazardous waste would result in fundamental changes to the way we operate and maintain the boiler and all ash handling equipment,” Bleth said. “Costs are undetermined but maintenance and disposal costs would be much higher.”
A letter signed by a bipartisan group of 45 U.S. senators was sent to President Obama on May 26 concerning the EPA’s proposed rulemaking for regulation of coal ash. The letter asked the Administration to “rapidly finalize” a rule regulating coal ash as nonhazardous. The letter stated that the Subtitle D designation will “improve the standards for CCR disposal, ensure a viable market for the beneficial use of CCRs and achieve near term meaningful environmental protection for disposed CCRs.”