Our Concentrating the MineTM concept integrates three enabling technologies that together have the potential to deliver a step change increase in the operations output, without a step change in operating and capital costs while delivering a significant reduction in energy and water use.
- Advanced Fragmentation. Developed with one of our technology partners, The University of Queensland, Advanced Fragmentation uses new blasting technologies to increase plant throughput and minimise processing costs. One of the most valuable aspects of smart blast design is the ability to blast to a fine ore fragmentation; in doing so we are able to increase volumes through the mills and therefore increase production. It is also more energy efficient because we can reduce the amount of rock we put through high energy grinding (only 1% of the energy in a grinding mill is actually used for breakage, the rest of the energy is lost in heat, vibration, etc). A further advantage is lower volumes of waste for tailings.
- Bulk sorting. We are also working on extracting metal more efficiently by separating ore from waste before it enters comminution. We are exploring pre-concentration techniques such as screening and sorting that use the natural variability of the ore body. Bulk ore sorting uses sensors to remove barren gangue from a fully loaded conveyor belt based on the grade. By rejecting the worthless rock (gangue) earlier in the process we can increase the grade, while reducing processing costs, and water and energy consumption. So it is simpler, less expensive and has a much smaller footprint than the current individual particle sorting technologies available. Progress in this space will be of huge value to us, especially in today’s low-grade mining operations.
- Coarse Particle Recovery or CPR. CPR is designed to follow the advanced fragmentation and gangue rejection technologies. It combines course particle flotation and dry stacking technologies. Essentially, it allows us to float particles at sizes two to three times larger than normal. This has two main benefits. Firstly we use less energy and can therefore increase our production rates; and secondly, we are able to easily extract water from the process leaving a waste stream that is dry and stackable. The upper size limit of coarse particle flotation has been a long-standing challenge in the industry, as the value of metal and minerals lost to tailings is often in particles too coarse to float (coarse particles are generally larger than 250 microns or 0.25mm, where, for example, 4% of Cu recovery can be lost). But regardless of how coarse one is able to process particles there has been, and always will be, a portion of ultra-fine particles that require processing. We have partnered with major chemical companies and are experimenting with new techniques to recover this previously unrecoverable metal. There are promising near term opportunities that we’re testing on metal fines making them easier to recover. Applicable across most of our core assets, CPR will allow us to reuse 80% of process water; this is an important step change given that water sent to tailings disposal often represents the largest water loss at a mine.
We are achieving outstanding results at our pilot plant in Chile, exceeding our performance targets for productivity, water and energy consumption, offset by a minor recovery loss. We are now preparing to extend the pilot from our copper to our platinum business and give momentum to this important pathway to precision processing.