Hydrated Lime Feeding for Water Treatment at Gold King Mine

Alexco Environmental offered an onsite solution including a 75-ton silo and feed system to feed hydrated lime to treat 200 to 800 gallons per minute of influent. Alexco contacted Vibra Screw Inc. of Totowa, New Jersey, for expertise on equipment for handling bulk powders to see what was needed and what could be shipped within a week. The company offered a volumetric screw feeder with variable speed drive and a controller with 4-20 mA remote speed input, which would allow the lime feed to automatically adjust to the changing pH of the influent. The higher the acidity, the more lime was continuously fed. The system would also treat the heavy metals

The system was up and running within weeks. It operates around the clock, even through the tough Colorado winter.