Sampling Mine Tailings and Measuring In-situ Density at the Lordsburg Mine, New Mexico

Mining has been an important part of New Mexico’s history for more than a century, leaving behind several mine tailings that provide valuable information on historical mining practices and mineral resources. Tailings are solid materials remaining after extraction of ore from physical processes (e.g. crushing, grinding) and chemical processes such as flotation, gravity and magnetic separation, cyanidation, and usually deposited in tailings storage facilities.

The Economic Geology Group at the NMBGMR is sampling mine wastes and tailings across New Mexico under the USGS Earth MRI funding critical minerals in mine waste program. As part of the ongoing mine wastes program, the Economic Geology team visited the Lordsburg Mine, Hidalgo County, in southwestern New Mexico to collect representative tailings samples and measure the in-situ density of the tailings deposit.

Representative composite samples were collected from several locations across the tailings pile using standard field sampling procedures. Each sampling location was documented by taking GPS coordinates, and samples were properly labelled before being transported to NMBGMR Economic Geology laboratory for further analysis. In addition to sampling, in-situ density test was conducted using the sand cone method to determine the bulk density of the tailings under natural field conditions.

Laboratory characterization will include particle-size analysis, specific gravity, mineralogy and whole-rock geochemical analysis to determine the minerals, major and trace elements present in the tailings. The data will contribute to ongoing research at NMBGMR evaluating critical mineral potential of mine wastes.