Havneholmen 2, 1-3
2450 Copenhagen SV
Denmark
The main challenge for the customer, a South American copper miner, at the initial stage was to keep a healthy level of inventory in the feeders to ensure a consistent feed between the rolls.
The attached graph shows the benefits obtained when implementing Expert Control for the HPGRs. The analysis shows an increase of 1745 t/h in throughput when Expert Control in turned on, this accounts for an increase of around 21%. The increase in tonnage for the HPGRs can be attributed to the tight control over the bin levels, by manipulating the moving bin and the feeders. These actions are taken every minute and have a significant impact on operational continuity and overall tonnage delivered to the grinding stage.
Another objective achieved by implementing Expert Control in the HPGRs is the increase in comminution energy by increasing power in the rolls. Figure 3 shows an increase in power of 680 kWt with the Expert System turned on, an increase of around 17.5%. By operating with higher power, you ensure that breakage occurs between the particles, alleviating the ball mills and increasing overall throughput. The average pressure between the rolls was also maximised which resulted in a finer product being discharged from the HPGRs.
To close the loop of benefits obtained with Expert Control we analysed the circulating load when the system is on. Figure 5 shows a decrease of 4.9% in circulating load for the crushing stage. This is because the expert system ensures a smaller ore when the system is on, by keeping an optimum layer of material between the rolls and by increasing power. By lowering the circulating load in crushing we can increase the fresh load that is fed to the equipment and also a finer ore will be fed to the grinding stage.
The main challenge for the customer, a South American copper miner, at the initial stage was to keep a healthy level of inventory in the feeders to ensure a consistent feed between the rolls. A layer of ore between the rolls helps the compression forces to break the particles more effectively and consequently a softer ore will be fed to the next stage.
To keep this layer of material at its desired level the operator must constantly monitor the level of the four discharge bins, making sure they don’t get too full (this can cause the feeder to get stuck between the discharge bins) or too empty (causing the rolls to stop resulting in a decrease in overall throughput). The process to fill the bins happens relatively quickly and the operator must monitor other equipment in the area at the same time, making the task of keeping everything at an optimal operation daunting.
Another challenge with the HPGRs is to maximise the comminution energy by increasing the power in the rolls. With hardness changes it is necessary to adjust the pressure dynamically to produce a softer ore for the ball mills.
