Comminution circuit design and simulation for the development of a novel high pressure grinding roll circuit

• Main Author: Rosario, Persio Pellegrini
• Language: English
• Published: University of British Columbia 2010
• Online Access: http://hdl.handle.net/2429/30231

The application of High Pressure Grinding Roll (HPGR) in comminution circuits is well established in processing cement, diamonds and iron ore. Recently, the application of HPGR has been extended to high-tonnage precious and base metals operations with hard ore. This is due to the HPGR: being more energy-efficient than grinding mills, not requiring steel grinding media, and providing higher throughputs than cone crushers. Although HPGR circuits are being used in high-tonnage precious and base metals, there is limited quantitative knowledge to indicate the true benefits or drawbacks of HPGR compared to Semi-autogenous mill (SAG). This lack of knowledge restricts the ability of designers to determine the optimal circuit. To address this lack of knowledge the research in this thesis: • Reviews the basics of the HPGR machine, its benefits and shortcomings. • Details the development of the SAG circuits and explains how the new generation of crushing circuits, with HPGR for tertiary crushing, are starting to replace SAG circuits in hard-rock mining. • Presents a structured methodology for comparison of the energy requirements for HPGR versus SAG complete circuits. The process is based on industrial best practices and advanced modelling tools, and is demonstrated through the evaluation of two hypothetical mining projects (based on real ore data). • Investigates the feasibility of a novel AG-Crusher-HPGR circuit using rock samples from a large copper-gold mining project. The approach was to develop and evaluate the circuit design for high-tonnage operations with mixed hardness ores containing clay. Previously, HPGR was considered only suitable for very hard ores and the technology was rejected for other cases. A unique pilot-plant test program was developed as a basis for experimental simulation. As a result the suitability of the circuit was demonstrated. The development of this novel circuit along with the findings of this research have the potential to improve future mining operations dealing with similar orebodies that, in fact, are major sources of base metals worldwide. The potential for significant savings in energy and steel media have been demonstrated. This may also lead to the selection of more sustainable circuits for a broader range of orebodies. === Applied Science, Faculty of === Mining Engineering, Keevil Institute of === Graduate