Rock hardness is a critical factor in the efficiency of mechanical rock breaking. Generally, as rock hardness increases, the efficiency of mechanical breaking decreases (ResearchGate, 2022).
Harder rocks require more energy and force to fracture, leading to slower breaking rates and increased power consumption. The cutting tools used on mechanical breakers must also be sufficiently hard and durable to effectively break the rock without excessive wear or failure (MDPI, 2019).
For example, roadheaders, which are effective in softer to medium-hard rock, face limitations in very hard rock due to the machine’s stiffness and the capacity of the cutting tools (Antraquip, 2016).
Similarly, the efficiency of continuous miners in coal mining is influenced by the hardness of the coal seam. In contrast, softer rocks like limestone can be broken more efficiently with lower energy requirements and less wear on equipment (HCROT, 2025).
The choice of mechanical breaking method and the design of the cutting tools are often dictated by the hardness of the rock to be excavated (ResearchGate, 2022).
Why is it harder to break very hard rocks with machines? Share your thoughts!
References:
ResearchGate. (2022). (PDF) MECHANICAL ROCK BREAKAGE MACHINES. https://www.researchgate.net/publication/361029430_MECHANICAL_ROCK_BREAKAGE_MACHINES
MDPI. (2019). Methods of Mechanical Mining of Compact-Rock—A Comparison of Efficiency and Energy Consumption. https://www.mdpi.com/1996-1073/12/18/3562
Antraquip. (2016). Roadheaders. https://www.antraquip.net/files/Antraquip%20WT%20Jan-Feb%2016.pdf
HCROT. (2025, May 6). How Does a Rock Breaker Work? A Comprehensive Guide for the Mining Industry. https://www.hcrot.com/how-does-a-rock-breaker-work-a-comprehensive-guide-for-the-mining-industry
