, Former Senior Research Prgrm Mngr, UMD-NRRI
The goal of this study was to evaluate the technical and economic viability of using coarse taconite tailings for aggregate purposes in road construction. Making use of this mining byproduct makes environmental sense because it maximizes the use of a resource that has already been mined and crushed. Technical data was obtained on samples from five sites, relating geological, mineralogical, and chemical properties to performance when used in road construction. A series of aggregate tests demonstrated the suitability and durability of coarse tailings as a component of bituminous asphalt. In addition, state-of-the-art testing methods showed that none of the samples contained asbestos. In terms of the marketing potential, low-cost rail transportation and a workable distribution plan would be key for expanding the use of coarse taconite tailings as aggregate in markets beyond Northeastern Minnesota.