A copper mine can produce more copper and less silver at the same time.
That complicates a familiar argument: if silver comes largely from by-product mining, expanding copper production should help replenish silver supply.
Sometimes it does. But the relationship is not automatic.
Consider a historical example from Sierra Gorda in Chile. In its July 2025 production report, KGHM reported that January–July payable copper production increased from 41,700 to 48,800 tonnes on its 55% ownership basis — roughly 17% growth.
Over the same period, payable silver production fell from 13.6 to 12.5 tonnes, a decline of approximately 8%. The same operation delivered opposite production trends for the two metals.
KGHM attributed the copper increase to higher copper content in the ore and improved recovery, despite processing less ore. It did not give a separate explanation for the cumulative silver decline in that report.
The mechanism is straightforward. Copper output can increase because each tonne of rock yields more copper, rather than because the plant processes more rock. That improvement does not establish that the same material contains more silver.
Silver ore grades vary across deposits and within individual mines. The quantity recovered also depends on processing performance. Copper production alone therefore cannot tell us how many additional silver ounces an operation will deliver.
For us, this changes how copper expansion announcements should enter a silver supply forecast. The useful questions are: how much additional ore will be processed, what silver grades does it contain, and how much silver can be recovered?
Silver’s price could double while its supply still depends heavily on decisions made at copper mines.
But even when those mines produce more copper, the extra silver still has to be demonstrated.
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