NRRI > Investigate Ideas for Further Processing of Taconite Coarse Tailings at the Plant Before Haulage and Stockpiling
Last Update Sun Mar 3 14:22:00 CST 2013
NRRI Duluth and Coleraine will work with each taconite facility to assess how and where coarse taconite tailings are produced in the facility`s flow sheet, and to determine if simple physical methods can be used to efficiently, cost-effectively recover one or more gradations from the process stream cost-effectively. Proposed work would include: 1) taconite plant visit and flow sheet evaluation; 2) development of sample collection/recovery strategy; 3) collect sufficient sample for physical, chemical, and mineralogical characterization; 4) suggest possible recovery methods; 5) estimate cost and benefit of implementing recovery methods; 6) summarize results and produce a final report of investigation.No new progress in the second half of 2012 due to ongoing and competing project commitments. Completing the final report in the first half of 2013 is anticipated, possibly augmented by some additional friction aggregate testing.
Based on its taconite aggregate investigations to date, the NRRI feels there is an excellent opportunity for generating value-added products on a modest scale at taconite facilities that make use of the full gradation spectrum of taconite coarse tailings. For example, plants that use spiral classifiers to separate fine and coarse tailings are already doing much of what a commercial aggregate washing/screening plant does to recover aggregate products like sealcoat chips, which are a premium-value aggregate product. Depending on the gradation, such products can sell for $15 to $20 per ton, FOB producer. Some specialty friction products, when dried and bagged, can sell for considerably greater amounts, e.g., over $150 per ton.
Investigation showed that it would take considerable effort and cost to implement a system to recover size-bracketed coarse tailings fractions at their point of generation, especially within taconite plants. An in-plant recovery system would be better suited for designing into a new operation’s process flow-sheet prior to construction, rather than retrofitting an existing one; space constraints and potential disruption of operations would pose challenges. Field sampling conducted by NRRI outside of a taconite facility, however, suggests that selective recovery – e.g., at a tailings basin discharge point – might be a simpler, more flexible, cost-effective alternative. This project also evaluated physical and mineralogical/microscopic properties of the tailings. A final report was in preparation, but due to other current and competing project commitments, completion of the final report was delayed. The final report is expected to be completed in the second half of 2012.
Start Date 05/01/2010
End Date 12/31/2012
Steven Hauck undefined