Recycling Fly Ash And Sludge For Profit

Mary Carpenter

Finding innovative uses for fly ash is nothing new for Milwaukee-based Wisconsin Electric (WE). Approxi-mately 15 years ago, the company launched an aggressive ash utilization program and since has marketed its ash by-products successfully to the construction industry. A $22 million light-weight aggregate plant, lo-cated in the company's Oak Creek, Wis., power plant, is WE's latest effort to manufacture a product from fly ash.

Now in its third year of operation, the plant is the world's only commercial-scale facility that produces structural-grade lightweight aggregate from coal combustion fly ash and municipal and paper mill wastewater sludges.

Using a unique process developed by WE and its affiliate, Minergy Corp. (both Wisconsin Energy Corp., Milwaukee, subsidiaries), the wastes are converted to an environmentally-benign, structural grade lightweight aggregate for construction use. The stone-like end product, Minergy LWA, is suitable for use in concrete products and in geotechnical, landscaping and asphalt-paving applications, or any application requiring stone, sand or gravel.

Historically, fly ash and sludges have been landfilled at a substantial cost. The Minergy process, however, can convert nearly all of these waste materials to a marketable product and to useful heat energy.

The technology combines fly ash from the Oak Creek power plant with wastewater sludge from the Milwau-kee Metropolitan Sewerage District and paper mill sludge from southern Wisconsin paper mills.

The sludges are proportioned, mixed and then fed to a pelletizer that creates pellets about 11/42-inch in diameter, according to plant manager Dick Dowdell.

"Dried pellets are fed to a rotary kiln for firing at temperatures near 2000Degrees Fahrenheit," he explained. "All the organic and volatile materials in the pellets are burned out, leaving a durable, light weight, ceramic-like aggregate."

Unlike conventional lightweight aggregate manufacturing processes that rely on a large amount of energy to power the process, the ash and sludges serve as fuel for most of the plant energy needs. To boost the process efficiency further, future plans include the installation of a waste-heat recovery boiler with a steam generating capacity of 40,000 pounds per hour, roughly equivalent to four megawatts of electricity.

After the aggregate product meets quality assurance requirements, it is stockpiled before it goes through a crushing and screening process to meet market needs. The product then is sold by WE under the Minergy LWA trademark.

LWA is the only structural grade lightweight aggregate produced in the upper Midwest and has been used in projects in five states and Canada. "We're seeing success in a number of construction projects, including an award-winning bridge in Sheboygan and numerous multi-story structures such as hospitals, libraries and office buildings," said Kevin Cavanaugh, LWA regional sales manager.

In addition, LWA is more environmentally benign than the two feedstocks. "All organic compounds in the fly ash and sludge are destroyed in the combustion process," said Dowdell. "Analysis of the heat-hardened aggregate shows that the leachate meets federal U.S. Environ-mental Protection Agency drinking water standards."

The Oak Creek processing facility is on schedule to achieve its design capacity to process 60,000 tons of sludge and 85,000 tons of fly ash into about 90,000 tons of lightweight aggregate per year. "The aggregate facility has advanced our goal of utilizing 100 percent of the coal fly ash from our power plants," said Tom Jansen, manager of LWA sales and marketing. "We currently market about 60 percent of the ash we produce compared to the industry ash utilization rate of 25 percent."

"The Minergy technology can be used wherever there is a potential market for lightweight aggregate and wherever fly ash and sludges can be economically shipped to one site," explained Tim Nechvatal, Minergy Corp.'s vice president.

In an industry that is rapidly moving beyond the traditional business of producing and delivering electricity, WE's LWA plant provides a glimpse of the effect growing competition will have on energy companies as they explore ways to enter new markets and offer new services.

Contracts Rader Resource Recovery Inc., Mem-phis, Tenn., has received a contract from Reciclados Industriales de Mexico (RIMEX) to supply material handling equipment for a new interim bottle facility in Mexico City, N.M.

The Florida Department of Environ-mental Protection has awarded Rust Environment and Infrastructure, Greenville, S.C., a four-year contract, valued at $8 million, for comprehensive environmental services at its statewide hazardous waste site/dry-cleaning solvent cleanup programs.

Distributor Mid-Atlantic Plastic Systems, Inc., Roselle, N.J., has been appointed the U.S. Agent for Julien Environmental Technology, Belgium., a manufacture of recycled plastic lumber molding machines and recycled plastic pallet molding machines.

Funding The Bedford Capital Co., New York, offers the Bedford Recycling Fund which focuses on firms engaged in one or more aspects of recycling, including processing, fabrication, manufacturing and marketing of recyclable materials collected from any source. For more information call (212) 688-5700.

Grant The California Integrated Waste Management Board, Sacramento, has awarded $3 million in grants to 34 local governments throughout the state to establish and expand programs to keep household hazardous wastes out of landfills.

Legislation Hollis Devoe, St. Paul, Minn., was convicted for dumping 95,000 tires in Olmsted County, Minn. Devoe was sentenced to 30 days in jail and received a $7,200 fine.

John Carr and Donald Wimmer, co-owners of Electro Precision Inc., each pled guilty to illegally storing and disposing of hazardous waste, ac-cording to Minnesota Pollution Control Agency, St. Paul. Carr will serve 120 days in jail; Wimmer will serve 60 days.

New Office ERL, Bloomfield, Conn., has opened a Southeast Regional Office. The address is 1132 Hemingway Ln., Roswell, Ga. 30075. (770) 643-6504. Fax: (770) 643-6507. ERL provides environmental consulting in hazardous waste compliance.

New Facility Waste Control Specialists, Abilene, Texas, has opened a new hazardous waste facility in Andrews County, Texas. The new facility includes an advanced research and development center focusing on waste treatment and reduction.

Request For Partnership Abu Sultan Trading & Cont. Est., Omani, desire to expand their waste and disposal services within the Muscat capital area. They are looking for overseas partners to provide the technology and financing. Contact: Ram Seshan, Abu Sultan Trading & Cont., P.O. Box 2513 Ruwi, Postal Code 112, Sultanate of Oman. Phone: 590968 or 591806. Fax: 591808

BATON ROUGE, La. - A specialized training program for compost facility managers/operators, originally in-tended to help operators become certified - a requirement in Louisiana by 1997 - has evolved into one of the country's premier educational composting programs.

The Compost Facility Operator Training Program is a three-and-a-half day classroom and laboratory course, which has been offered by the Louisiana State University's Agricul-tural Center since 1993. Some 120 students have taken the course, and de-mand for instruction is greater than it can accommodate. This year's training dates are set for May 13-16 and Octo-ber 14-17. It is funded through a grant from the U.S. Department of Agriculture's Natural Resources Con-servation Service.

Program topics include field dem-onstrations, compost biology, micro-organisms of composting, compostable materials, systems, mixing and recipes, material preparation and handling, facility safety, managing the process, quality and standards, marketing and economics, lab operations, regulations, odor control, sampling and testing techniques.

Course instructors include personnel with the LSU Ag Center's educational and research branches, the Louisiana Cooperative Extension Ser-vice, the Louisiana Agricultural Ex-periment Station and compost industry professionals such as Phil Leege, Procter & Gamble Co.'s senior compost engineer and chair of the Na-tional Composting Council's, Alex-andria, Va., Standards and Practices Committee.

"We've been concentrating on producing compost," Leege said. "Now we need to understand the users of it so that we understand their needs and are able to focus our production based on specific customer needs."

In addition to the course, the LSU Ag Center has an outdoor compost teaching facility, located near the campus in Baton Rouge. Currently, the facility is being considered for pilot testing of national compost standards. The training facility also soon will be expanded to a new 8.5-acre site near the present facility.

To learn more about the LSU Ag Center's Compost Facility Operating Training course, contact Bill Carney, LSU Agricultural Center, P.O. Box 25100, Baton Rouge, La. 70894-5100. (504) 388-6998. Fax: (504) 388-2478. E-Mail: [email protected]

Funding The Bedford Capital Co., New York City, offers the Bedford Recycling Fund which focuses on firms en-gaged in one or more aspects of re-cycling, including processing, fabrication, manufacturing and market- ing of recyclable materials collected from any source. For more information call (212) 688-5700.

Merger Republic Industries Inc., Ft. Lauder-dale, Fla., has merged with Taro-mina Industries, Anaheim, Calif. The $250 million transaction will be ac-counted for as a pooling of interest.

People Leach Co., Oshkosh, Wis., has ap-pointed Bruce D. Yakley as its new chief operating officer. Hollis Devoe, St. Paul, Minn., was convicted for dumping 95,000 tires in Olmsted County, Minn. Devoe was sentenced to 30 days in jail and received a $7,200 fine.

John Carr and Donald Wimmer, co-owners of Electro Precision Inc., each pled guilty to illegally storing and disposing of hazardous waste, ac-cording to Minnesota Pollution Control Agency, St. Paul. Carr will serve 120 days in jail; Wimmer will serve 60 days.

New Office ERL, Bloomfield, Conn., has opened a Southeast Regional Office. The address is 1132 Hemingway Ln., Roswell, Ga. 30075. (770) 643-6504. Fax: (770) 643-6507. ERL provides environmental consulting in hazardous waste compliance.

New Facility Waste Control Specialists, Abilene, Texas, has opened a new hazardous waste facility in Andrews County, Texas. The new facility includes an advanced research and development center focusing on waste treatment and reduction.

Request For Partnership Abu Sultan Trading & Cont. Est., Omani, desire to expand their waste and disposal services within the Muscat capital area. They are looking for overseas partners to provide the technology and financing. Contact: Ram Seshan, Abu Sultan Trading & Cont., P.O. Box 2513 Ruwi, Postal Code 112, Sultanate of Oman. Phone: 590968 or 591806. Fax: 591808