Waste rock that gets mined along with the ore, lowering the grade that reaches the mill.
The unavoidable contamination of ore with waste rock during mining, which lowers the average grade of material sent to the mill. Dilution is expressed as a percentage and must be accounted for in resource estimates and mine planning.
Dilution is the gap between the grade in the resource model and the grade the plant actually sees. Narrow-vein underground mines suffer it most, and a project that models 5% dilution but delivers 25% has an entirely different cost structure than its study described.
In mining this word means rock, not shares. The financing sense of dilution is a separate concept and the two appear in the same documents.
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