Mining

Why does recovered metal fall short of the resource model?

The model promises one number and the mill delivers another. The gap has a name, and a dollar value.

June 20264 min read

Where the gap opens

Reconciliation compares grade and metal across four stages: the reserve model, the ore-control model, delivered to mill, and received at mill. Over-optimistic models, poor selectivity, and unplanned dilution open the gap, and each stage carries a direct dollar value.

Measure the mine-call factor

The factors track it: F1 for orebody knowledge and selectivity, F2 for dilution and ore loss into the mill, and the mine-call factor F3 for how much reserve metal you actually recover. A persistent F3 below one is leaking revenue. The framework is set out by bodies like AusIMM.

Where the ERP closes the loop

On Hudace, grade-control assays, weighbridge and conveyor tonnage, and mill metallurgical accounting feed one system, so the factors compute continuously instead of in a monthly spreadsheet. Xenon AI shows where dilution or ore loss concentrates, by bench, blast, or shift, and flags drift.

A geologist or metallurgist investigates and signs off. AI does not re-classify reserves.

The numbers to watch

Reconcile the chain, do not average it away.

Mine-call factor (F3)

Received-at-mill metal / reserve metal depleted. How much you actually recover.

F1 factor

Ore-control metal / reserve metal. Orebody knowledge and selectivity.

F2 factor

Received / delivered metal. Unplanned dilution and ore loss into the stream.

Grade variance

Modelled vs delivered grade. Where the reconciliation gap concentrates.

See live reconciliation on Hudace

Talk to our team about computing the mine-call factor continuously.

Request a demo