Mechanical mining is more common in soft rock than in hard rock primarily due to the limitations of current mechanical cutting technology when dealing with high rock strength and abrasiveness (Mining Magazine, 2016).
Force Requirements: Harder rocks require significantly greater forces to fracture mechanically. Machines designed for soft rock often lack the power and thrust needed to efficiently break hard rock (Inside Mines, Unknown).
Tool Wear: Mechanical cutting tools, typically equipped with tungsten carbide tips, experience rapid wear and failure when used on hard and abrasive rocks (ResearchGate, 2016).
This leads to frequent tool changes, increased downtime, and higher operational costs, making mechanical mining less economical in such conditions (Journal of Mining and Environment, 2010).
Machine Limitations: The stiffness and overall robustness of mechanical mining machines, particularly roadheaders and continuous miners, can be limiting factors in hard rock excavation. These machines may struggle to maintain effective contact with the rock face and achieve sufficient penetration in high-strength materials (Antraquip, 2016).
In contrast, soft rocks require less force to break and cause less wear on cutting tools, allowing mechanical miners to operate more efficiently and economically (ResearchGate, 2017).
As a result, mechanical methods like continuous mining are widely used in softer deposits such as coal, potash, and salt (Mining Magazine, 2016).
Why do you think mechanical mining is more effective in soft rock than in hard rock? Share your thoughts!
References:
Mining Magazine. (2016, November). MM’s technologies. https://www.miningmagazine.com/fleets/news/1261932/mms-technologies
Inside Mines. (Unknown). Performance Prediction of Mechanical Excavators. https://inside.mines.edu/UserFiles/File/earthMechanics/performance_prediction_of_mechanical_excavators/performance_prediction4.pdf
ResearchGate. (2016). A review of rock cutting for underground mining: past, present, and future. https://scielo.org.za/scielo.php?script=sci_arttext&pid=S2225-62532016001100006
Journal of Mining and Environment. (2010). A state-of-the-art review of mechanical rock excavation technologies. https://jme.shahroodut.ac.ir/article_4_72b0cc9fcdcecffc8e4b8fff3c75aa59.pdf
Antraquip. (2016). Roadheaders. https://www.antraquip.net/files/Antraquip%20WT%20Jan-Feb%2016.pdf
ResearchGate. (2017). Applicability of Continuous Miner in Room and Pillar Mining System: Higher Production and Productivity with Safety. https://www.researchgate.net/publication/312947652_Applicability_of_Continuous_Miner_in_Room_and_Pillar_Mining_System_Higher_Production_and_Productivity_with_Safety
