Dilution is a critical factor in mining that directly impacts ore quality, operational efficiency, and overall project economics. Understanding its root causes is essential for effective mine planning and control. This discussion outlines the primary geological and operational factors contributing to dilution during the mining process.
Geological Causes
- Orebody Geometry and Boundaries: Irregular shapes, indistinct boundaries between ore and waste, and complex orebody structures make it difficult to extract only the valuable material(Jorquera, n.d.).
- Internal Waste Zones: Waste or low-grade material embedded within the orebody, which cannot be mined separately, leads to unavoidable internal dilution(Understanding the Operation of Grinding Mills in the Mining and Mineral Processing Industry – NEWS – SMMVIK Machinery, n.d.).
- Structural Complexity: Features such as faults, fractures, and varying rock characteristics can promote the mixing of waste and ore.
Operational Causes
- Inaccurate Drilling and Blasting: Misaligned drill holes and excessive breakage during blasting can lead to the extraction of surrounding waste.
- Inappropriate Equipment or Mining Methods: Using oversized equipment or methods with low precision can result in mining beyond the ore boundaries, increasing dilution(Mining Dilution: Increasing Productivity with Pitram – Micromine – Technology for Mining, n.d.).
- Poor Extraction Sequence and Stope Design: Inefficient planning or design of stopes and mining sequence can expose more waste, raising dilution levels.
- Improper Backfilling: Failing to properly manage or maintain backfill integrity can lead to waste or backfill material being mined along with the ore.
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Reference:
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Jorquera, M. (n.d.). Underground mining dilution: Management, trends and the role of machine learning.
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Mining Dilution: Increasing productivity with Pitram—Micromine—Technology for Mining. (n.d.). Retrieved October 13, 2025, from https://www.micromine.com/mining-dilution/
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Understanding the operation of grinding mills in the mining and mineral processing industry—NEWS – SMMVIK Machinery. (n.d.). Retrieved September 17, 2025, from https://www.millvik.com/news/understanding-the-operation-of-grinding.html
