Investigating the size reduction and energy performance of the innovative GRolls® crushing technology on porphyry copper gold and magnetite ore feed materials

Comminution in mineral processing circuits is dominated by dry crushing followed by energy and water intensive tumbling mills in grinding circuits which require grinding media. Emerging ore bodies are increasingly more complex, lower grade and located in remote locations with limited energy and water infrastructure. Dry comminution technologies such as the high pressure grinding rolls and vertical roller mills are increasingly adopted to reduce energy, water and grinding media consumption. The GRolls® technology extends energy efficient crushing mechanisms to achieve fine dry comminution without grinding media. Laboratory-scale testing was conducted on three representative ores, a porphyry Cu Au and two magnetite ores, across a range of feed sizes, operating configurations and moisture conditions using a laboratory scale GRolls400 unit. The crushing technology generated consistent steep narrow sized discharge products between 75 μm and 425 μm, under both dry and wet conditions, demonstrating stable performance across variable feed characteristics. These results indicate that GRolls® comminution may enable efficient early-stage gangue rejection and reduced reliance on energy intensive wet grinding circuits. The approach provides a potential pathway for processing complex ores in water and energy constrained environments. Gyratory Roller Crusher (GRolls®). New comminution technology for secondary grinding applications targeting early gangue rejection. Demonstrated high size reduction for very hard to soft ore feeds to 37 mm, ideal for <5 mm feeds. Short residence time in multiple crushing chambers across the rollers generates consistent steep narrow sized products between 75 μm and 425 μm with variable feed, dry or wet and no over-grinding. No grinding media. • Laboratory GRolls400 generates large size reduction and steep psd curves within a consistent narrow range in a single pass dry or wet without media • Energy consumption from 4 to 7 kWh/t for <5 mm feeds and to 10 kWh/t for coarser ore feeds • Performance favourable for secondary grinding and early gangue rejection