Dry processing of magnetic iron ores – addressing cost and environmental issues
W Skinner (1) and J R Kelly (2)
AusIMM Iron Ore 2017 Conference, Perth, Australia, 24-26 July 2017. Paper Number: 86
The Iron ore industry has reached the end of an unprecedented period of expansion triggered by China‘s demand for iron ore. Currently, lower ore prices have led producers to focus on optimizing mining operations while extracting the maximum tonnage from the infrastructure presently in place or from projects already underway. The rising global surplus will further force ore prices down and lead to output curtailments which in turn will help to restore market balance. However, investment in the development of new resources and the building of new infrastructure will inevitably become necessary. Making the right decisions in relation to future upgrade processing infrastructure when demand is uncertain will not be as straightforward as in the past where expanding the scale of a proposed plant has been the answer to ensuring economic viability. Overall cost and environmental pressures particularly in relation to wet processing will dominate the decision making process. IMP Technologies (IMPTEC) has anticipated the need for a dry low cost processing alternative which can open the way for the development of lower grade magnetite deposits and ensure the sustainability of processing in Australia. The lower grade magnetite deposits are generally fine grained and require grinding to p80’s of 30 to 40 microns. Historically, the cost of grinding to these sizes has been and remains the key factor determining the economic viability of a magnetite processing operation. The proposed dry processing alternative totally eliminates grinding with coarse crushing, fine crushing and super-fine crushing down to liberation size. IMPTEC’s Super-fine Crusher in combination with its “Cyclomag” dry magnetic separator feature in a proposed low cost and environmentally friendly open circuit flow sheet producing a high-grade pellet plant feed. The Cyclomag has demonstrated the capacity to match the performance of wet drum magnetic separators over the coarser size range, while improving on the performance of the wet drum at ultra-fine size. This paper reports on the results of super-fine crushing and Cyclomag separation test-work, focused on supporting the feasibility of the proposed dry processing route for the production of high grade pellet plant feed from a typical fine grained low grade magnetic ore.
(1) Future Industries Institute – University of South Australia
(2) Director – IMP Technologies P/L
Skinner W and Kelly J R, Dry processing of magnetic iron ores – addressing cost and environmental issues. In Proceedings of the AusIMM Iron Ore 2017 Conference, Perth, Australia, 24-26 July 2017, The Australasian Institute of Mining and Metallurgy.