Stability of water treatment sludge, Climax Mine, Colorado Part I: Chemical and mineralogical properties

Ponds have been used as reactors for lime neutralization water treatment at the Climax Molybdenum Mine since 1977, with sludge disposed of in two of the three tailings impoundments at the site. Proposed changes to the water treatment process resulted in a program to determine the long-term geochemical stability of sludge in the Mayflower impoundment. Sludge samples were collected from four locations in the Mayflower impoundment to evaluate the spatial variability of water treatment products throughout the water pool. Bulk chemical analyses, static acid generation tests, X-ray diffraction and electron microprobe analyses were performed, and indicate that the samples can be subdivided into those dominated by water treatment sludge and those with a significant tailings component, derived from the underlying impoundment.