A Concise Method for Mine Soils Analysis

Abstract

A large number of abandoned hard rock mines exist in Colorado and other mountain west states, many on public property. Public pressure and resulting policy changes have become a driving force in the reclamation of these sites. Two of the key reclamation issues for these sites is the occurrence of acid forming materials (AFMs) in mine soils, and acid mine drainage (AMD) issuing from mine adits. An AMD treatment system design project for the Forest Queen mine in Colorado's San Juan mountains raised the need for a simple, useable method for analysis of mine land soils, both for suitability as a construction material, and to determine the AFM content and potential for acid release. We have developed a simple, stepwise, go-no go test for the analysis of mine soils. Samples were collected from a variety of sites in the Silverton, CO area, and subjected to three tiers of tests including: paste pH, Eh, and I 0% HCl fizz test; then total digestion in HNO,IHCl, neutralization •potential, exposure to meteoric water, and toxicity content leaching procedure (TCLP). All elemental analyses were performed with an inductively-coupled plasma (ICP) spectrometer. Elimination of samples via the first two testing tiers left two remaining samples, which were subsequently subjected to column and sequential batch tests, with further elemental analysis by ICP. Based on these tests, one sample was chosen for suitability as a construction material for the Forest Queen treatment system basins. Further simplification, and testing on two pairs of independent soil samples, has resulted in a final analytical method suitable for general use.

A Physical and Chemical Assessment of the Maude Monroe Mine Site

“…This is a key reason why the Mine Waste Decision Tree (MWDT) was created (Wildeman, Smith, and Ranville, 2007). The MWDT and the tests and observations that accompany it were developed by research at the US Geological Survey (USGS) (Smith, et al, 200, Hageman andBriggs, 2000, Hageman et al, 2005) and the Colorado School of Mines (CSM) (Winkler et al 1999, Herron et al, 2001, Heflin et al, 2004 to provide a comprehensive structure for assessing whether questionable mine wastes present a physical and chemical danger to the environment. The purpose of this paper is to offer an example of how this all encompassing tool can be useful for the training of environmental engineers and others who are perhaps not specialized in the remediation of mine spoils.…”