Mining companies have limited control over declining ore grades, but they can determine how efficiently each tonne of increasingly difficult material is processed. That is making crushing and grinding a major focus of mining technology development, as producers look for ways to reduce energy consumption while maintaining metal output.
Grinding Efficiency Becomes Critical
Weir is developing processing flowsheets that combine high-pressure grinding rolls (HPGR), large-format screening, stirred milling and coarse-particle flotation. The company has highlighted potential energy reductions of up to approximately 40% from HPGR technology and around 38% from stirred milling in suitable applications. Metso is addressing the same challenge through technologies including HPGR, fine grinding and vertical roller mills. Its Loesche-based dry-grinding solutions have been presented as capable of reducing energy requirements by up to roughly 40% for appropriate ore types.
Actual savings vary significantly depending on the deposit, ore characteristics and overall processing flowsheet. The potential impact is substantial because comminution represents one of the largest electricity demands at many hard-rock mining operations.
Lower-Grade Ores Increase Processing Pressure
The challenge is particularly significant for copper mines, where maintaining production from lower-grade resources can require substantially more material to be mined, transported and milled. More efficient comminution can therefore influence far more than electricity costs.
Reducing energy consumption per tonne can affect operating expenditure, processing capacity and infrastructure requirements, potentially allowing projects to meet production targets with lower energy demand. A mine that requires less power may also need less additional generation capacity, transmission infrastructure and backup supply. That can reduce capital requirements and potentially shorten development timelines.
Equipment Selection Is Changing
These pressures are also changing the way mining companies evaluate processing equipment. Rather than focusing primarily on throughput, operators are increasingly examining energy consumption per tonne, wear rates, maintenance requirements and downstream recovery when selecting crushers, mills and other comminution equipment. Suppliers that can improve several of these performance measures at the same time can gain an advantage as miners seek to control costs across the entire processing circuit.
The importance of comminution is likely to increase as accessible, higher-grade resources become harder to develop. The mining industry cannot depend on continuously discovering richer deposits to offset declining resource quality. Instead, producers will increasingly need to extract more valuable material from lower-grade and more challenging ores. That makes efficient comminution more than an environmental or energy-saving initiative. It is becoming a fundamental response to the changing quality of mineral resources and a key area for improving the economics of future copper, gold and other hard-rock mining projects.
