ENVIRONMENTAL AND HEALTH IMPACT ASSESSMENT OF MINING TAILINGS: A CASE STUDY FROM THE RANDSBURG MINING COMPLEX, CALIFORNIA

Mining tailings are waste deposits left after mining operations conclude, found in large quantities worldwide after the extraction of valuable materials like gold, silver, and tungsten. The decomposition of these tailings involves the absorption of atmospheric carbon and the leaching of harmful contaminants, such as heavy metals, into the environment. As tailings break down, their constituent materials interact more with their surroundings. Elements like magnesium and calcium can bond with atmospheric carbon, sequestering it as calcium carbonate, which is beneficial for the environment. However, leftover materials like tungsten, sulfur, and lead, especially in wet or humid conditions, pose significant environmental and human health risks. This study evaluates the environmental impacts using samples from the Atolia Mining Camp and Blackhawk Mine of the Randsburg mining complex in the Mojave Desert and the Basin and Range, California. Field surveys reveal large patches of yellow material on the surface of Blackhawk's tailings pile. We conduct mineralogical and heavy metal analyses using X-Ray Diffraction (XRD) and X-Ray Fluorescence (XRF) on samples from these sites. The yellow material is identified as sulfur deposits through XRD analysis. Preliminary results also indicate high amounts of quartz, feldspar, and calcite, along with sulfate-related minerals such as gypsum. Further analysis seeks to quantify these findings and identify specific minerals that may pose health hazards. Through comprehensive characterization, we aim to enhance the understanding of the environmental impacts of mining tailings and contribute to improved waste management practices.