The precipitator works as a dust collector before gases enter the smoke stacks. A sonic boom shakes off the dust collected on special wires in the precipitator. The dust, or particulates, is taken away by truck or slurried and stored on site.

When the company first started running the precipitator, 100 tons of dust a day was collected from emissions, but now 150 tons per day is being collected, Wilson said.Installation of 10 additional spray nozzles in each open hearth scrubber located in the smoke stack has also increased particulate removal, Wilson said. The scrubber operates with a fine mist that coats particulates.

The mist becomes a cloud, and once water droplets coat particulates, they become heavy and condense. The water-coated particulates run down through a pipe as slurry and are pumped into a pond.

What remains is a red dust that is 68 percent iron and is actually rust. Geneva hopes to reclaim that iron in the future and put it back into the blast furnace, Erickson said.