In most metal mining operations the in-situ ore is separated from the waste rock and is subjected to a series of breakage and separation processes to recover the valuable material from the waste. Profitability in this industry depends on how efficiently the in-situ rock is converted into the final valuable product.
Despite of the fact that the breakage and separation processes that take place at the mine and mill are inter-dependent, traditionally, mining and milling processes are managed and optimised as separate cost centres with little understanding of the impact of one process over the other. In the late 1990's, researchers at the University of Queensland have proposed a concept popularly called "Mine to Mill Optimisation" and demonstrated that all the processes in the mine to mill value chain are inter-dependent and blast fragmentation (or particle size distribution) play a critical on downstream processes especially on the downstream AG/SAG mills. During the initial stages, the focus was on producing finer fragmentation from blasts such that the fine particles can increase SAG/AG mill throughput where there is enough capacity in the ball mills. However, the first generation mine to mill strategy has the following limitations:
- Finer fragmentation from the blasts made the circuit ball mill constrained limiting mill throughput and or making circuit to grind coarser, effecting recovery.
- Indiscriminate increase of blast energy without understanding its impact on dilution and damage lead to poor overall meal output and higher risks of wall damage.
The Advanced Mine to Mill concept recognised these limitations and developed practical strategies to address them. A brief list of some of these strategies is given below:
- Produce optimum size distribution (not just finer) and balancing the transfer size between the SAG and ball mill to improve the overall circuit throughput (Powell et.al 2018).
- Implement production schedules and blending strategies to main consistent and optimum feed size and hardness to the mill.
- Implement strategies to minimise dilution, ore loss and damage from blasting without compromising on fragmentation (Picorelli et. al. 2018).
- Techniques to quantify the ore variability from advanced laboratory tests and by using the measure while drilling parameters from blasthole drilling (Parades et.al 2018, Faramazari et.al 2018).
This workshop is designed to explain the basic principles of Advanced Mine to Mill strategies and then how to apply them in the field. It provides practical solutions and case studies to demonstrate the potential value of these strategies. Finally, the workshop will increase the awareness and communication between mining engineers and metallurgists to work collaboratively by providing them with practical problem solving exercises.
This workshop is aimed for drill and blast engineers, mine superintendants, metallurgists, plan superintendants, mine managers, concentrator managers, general managers, asset optimization managers and business improvement managers - personnel responsible to improve the overall productivity of operations.