Millhead grade refers to the metal content or concentration of valuable minerals in the ore as it is delivered from the mine to the processing mill. It represents the average grade of the ore fed into the mill for processing, which is critical for determining the potential profitability and operational efficiency of a mining project.
This grade is typically expressed in units such as grams per tonne (g/t) for precious metals like gold or as a percentage for other metals. The millhead grade is often lower than the reserve grade due to dilution by non-ore materials during mining.
A higher millhead grade means that less ore needs to be processed to extract a unit of metal, which can reduce processing costs and environmental impact. Conversely, a lower millhead grade requires processing more material, increasing costs and potentially affecting economic viability.
In summary, millhead grade is the concentration of metal in the mined ore as it enters the mill, serving as a key indicator of ore quality and a fundamental factor in mining economics and operational planning.
