Dust suppression at Linwood’s limestone plant

Linwood Mining has reduced downtime at its limestone mining operation with a high-powered dust suppression system from Dust Control Technology.

Linwood had previously been using hoses and truck-mounted spray bars to help control dust at the crusher and transfer points, but results were always marginal. An electronic monitor constantly samples air quality in the mining area and the data is forwarded to both Linwood’s control room and to the Iowa Department of Natural Resources (DNR). Dust emissions from Linwood’s plant must remain within a specified range, in order to comply with strict government standards. If the DNR air monitor readings exceed pre-set limits, a shut-down is mandatory until the 24-hour averages return to acceptable levels.

By avoiding forced shutdowns due to high dust readings that had plagued the site, the portable equipment has saved thousands of dollars in lost production, while allowing reassignment of manpower previously spent handling water hoses.

The solution

Linwood officials visiting the ConEXPO / ConAgg trade show came upon a booth hosted by Dust Control Technology. Here, the company saw the DustBoss^Ò DB-60 - a portable suppression unit designed with special atomising nozzles to create a fine mist of water droplets that are the optimum size for dust control, launching them great distances with a powerful 25 HP fan. Linwood rented the DB-60 on a trial basis and used it to cover the area immediately surrounding the primary impact crusher, a Universal 4650 that reduces the freshly-mined stone to 5 in minus.

The DB-60 quickly proved successful, helping to reduce shutdowns as a result of dust emissions. Linwood officials reported a rise in production levels and, as a result, decided to purchase the machine.

In addition to a reduction in airborne particles and reduced labour costs, the DustBoss has also eliminated troublesome oversaturation of material. Plant Manager, Jim Petersen, noted: “Material purity is a critical issue, and you might not think dust control is part of that, but dirt and other contaminants contribute to the formation of air pockets in asphalt, and can also cause cracking or pop-outs on the surface of finished concrete.

“Since it’s portable and can be aimed as needed, the DustBoss provides flexibility when dealing with the wind,” Petersen continued. “The unit’s performance has definitely met and even exceeded our requirements. We’ve run the DB-60 over the dustiest materials we process, and it’s done exactly what we’ve needed it to."

Adapted from press release by Callum O’Reilly

The full version of this article will be published in the October 2012 issue of World Cement

Read the article online at: https://www.worldcement.com/the-americas/01102012/dust_suppression_linwood_mining_limestone_plant/