DCT unit targets slag recycling dust

A tower-mounted mister unit from Dust Control Technology (DCT), Peoria, Illinois, is helping to contain fugitive dust emissions at a slag crushing and recycling operation in Rancho Cucamonga, California.

A Canadian environmental solutions firm operating a slag recycling plant in California is using the industrial atomized mist technology to satisfy strict state air quality regulations, according to a DCT news release.

Tervita Corp., based in Calgary, Alberta, Canada, was tasked with controlling dust while conserving water in Rancho Cucamonga, an area known for high winds. The firm has accomplished it with the help of a tower-mounted DustBoss DB-60, sent in a modified shipping that stabilizes the unit and protects electronics. The result is “a drastic reduction in fugitive dust emissions, improved regulatory compliance and better community relations,” says DCT.

In 2012, steelmaker Gerdau Corp. chose Tervita to take over operations of the slag processing plant, which serves the company’s steel mill located nearby. Facing a transition that required updated equipment in a strict regulatory environment, Tervita managers worked closely with the South Coast Air Quality Management District (SCAQMD) and local leaders to create an air quality management plan designed to make the operation compliant and more efficient.

Tervita receives approximately 300 tons of material per a day in dump trucks, which are offloaded into a 200-foot-deep by 100-foot-wide storage area separated into two sections. Nearly a third of the temperature of the surface of the sun, newly delivered slag -- approximately 2,500 to 3,000 degrees Fahrenheit -- is wetted, cooled, mixed and cured by a combination of water, front loader and time.

“When we installed the new state-of-the-art crusher, we streamlined the recycling process into a faster operation that is dust-free because of the bag house filtration system,” says Carson Swartz, operations supervisor for Tervita. “But the storage and cooling area was a big issue. Whether offloading, churning or moving the slag to the crusher, it’s constantly being disrupted, causing a lot of dust.”

Prior to installing the DB-60, the company tried using a moveable sprinkler irrigation system left in place by the previous operators. Tervita found the sprinkler system only saturated the surface material, which caused large amounts of runoff and did not properly address the fugitive dust, says DCT.

Atomization can introduce more droplets into the air than hoses or sprinklers, using a fraction of the water volume. Because the mist is propelled by a fan rather than water pressure, the DB-60 uses less water to cover the area. Not only do the atomized droplets capture airborne particles, once they land they also quench the storage piles, offering surface suppression with far less runoff and product loss, according to DCT.

“As much as we run the machine, we’ve been impressed by how well it’s held up,” Swartz says of the DB-60. “Since the installation, the couple of times we’ve called DCT, they were very responsive and even came out to visit just to see the setup. Their service matches the quality of the equipment.”