*G. BALLANTYNE1,2 & A. GIBLETT3
SAG Conference Vancouver, Canada September 22 – 26, 2019
Newmont has a demonstrated history as a leading investor in comminution technology developments. Most notably the cornerstone high pressure grinding rolls (HPGR) demonstration plant at the Lone Tree operation in 2003, which contributed to paving the way for the subsequent acceptance of HPGR technology in the hard rock mining industry. Newmont endeavours to evaluate grinding circuit performance at its global operations, allowing continuous improvement of operating facilities and practical insights to be applied to new plant designs. This approach was demonstrated by a global mine-to-mill operations review in 2009, incorporating circuit sampling and standard ore characterisation testwork to facilitate the assessment of circuit performance efficiency and increased circuit productivity. This effort, and an ongoing commitment to performance analysis, has resulted in a performance-based dataset defining 15 individual comminution circuits. The database further provides a useful basis for comparing the available techniques to define circuit comminution efficiency.
In this paper, the authors will review various methods for assessing comminution circuit efficiency in the context of the Newmont database, including the Bond, Morrell, and size specific energy (SSE) methodologies. The authors will show that SSE method generates a relative efficient measure that allows equipment performance to be assessed in isolation and is in that sense comparable to the Morrell approach, whereas the published Bond approach is better suited to overall circuit analysis. The combination of these three methods allows a comprehensive understanding of the effectiveness of each comminution circuit, highlighting improvement opportunities, and providing a baseline from which the potential of new technologies can be measured.
The results of this analysis were also plotted on the comminution energy curves, a free platform provided by the Coalition for Eco Efficient Comminution (CEEC) and the Julius Kruttschnitt Mineral Research Centre (JKMRC). The energy intensity of each Newmont site was assessed using four individual energy indices.
In this paper, the authors will discuss the insights generated from each analysis method and demonstrate their relative merits as observed for the operations studied in this assessment.
Energy efficiency, SAG milling, Ball milling, Bond, Morrell