Opportunities to improve mill operations are often cited by mining companies and recognised in many concentrators spread throughout the world but are not always followed through. Copper-molybdenum concentrator operations are challenged by a continuously increasing list of detrimental factors. They include deteriorating ore characteristics and poor mineralogical information on deeper ores, water quality and availability, steel wear and increasing power costs. Rapidly declining productivity, sustainability and environmental factors, new taxes, mining industry global skill set shortages, to name but a few, must also be considered. The days of maximising value by just increasing production or simple cost cutting are fading and will not be sufficient for the future of more complex mineral processing operations and larger plants. As a result, FLSmidth's Global Process Technology Group has launched a plant and process optimisation program based on mineralogical and metallurgical surveys.
Copper-molybdenum concentrators of the future need a paradigm shift. Modelling and simulation tools alone are not the answer to complex mineralogical associations and larger scale equipment and operations. Detailed area by area review aimed at identifying process constraints in terms of equipment and operating practice in conjunction with robust diagnostic work, ie mineralogical and metallurgical characterisation, are mandatory for process optimisation. The navigational beacon, for all operations who want to remain competitive, will be ‘process efficiency'. Since the use of automated mineral analysers has become more readily available and reliable, mineralogical-metallurgical plant surveys have proven themselves as the most efficient tool for optimising plant performance.
The following paper will illustrate how operations can move
toward eliminating under-performing flow sheets, fixing run-away flotation
conditions, maximising individual process equipment performance, preventing
shortcuts in Bond work index testing which may cause the failure of comminution
models and minimising costly and time-consuming ‘debottlenecking'. As previous
plant surveys have shown, the net project cash flow can be increased by 50 to
200 per cent if a combination of robust ore characterisation and plant process
mineralogy is performed. The combined plant survey approach has been
demonstrated successfully in a multitude of operations. This includes the use of
key ore types in concert with statistically sampled process streams, bench-scale
metallurgical tests and automated mineral analysis on a size-by-size basis.
Meadows, D, Hall, G, Rose, D,
Thompson, P, Baum, W, Zahn, R and Yu, S, 2014. Copper-molybdenum concentrator
surveys using mineralogy and process benchmarking tools to improve overall plant
performance, in Proceedings 12th AusIMM Mill Operators' Conference
2014 , pp 315–322 (The Australasian Institute of Mining and Metallurgy: Melbourne).