What proportion of global silver supply comes from by‑product producers and how does that limit rapid production growth?
Executive summary
Roughly 70–75% of mined silver today is produced as a by‑product of other metal mines, leaving only about 25–30% from primary silver mines [1] [2] [3]. That production structure makes supply largely inelastic — higher silver prices do not automatically yield large, rapid increases in output, because most silver output is tied to the economics and activity of copper, lead, zinc and gold operations rather than silver itself [2] [4].
1. How much of global silver is a by‑product — the headline number and its consistency
Multiple market reports converge around the same range: analysts and academic work put by‑product (co‑product) silver at roughly 70–75% of total mined silver, with primary silver mines accounting for roughly 25–30% of supply [1] [2] [3] [4]. The ScienceDirect modelling paper cites 72% of primary silver produced as co‑product and explicitly flags that as a structural feature that inhibits rapid expansion [5].
2. Why a by‑product dominated supply profile constrains rapid growth
When silver is a by‑product, its output is governed by investment and operational decisions aimed at base metals or gold; expanding silver output therefore usually requires higher investment in copper or lead/zinc capacity or the development of new primary silver mines — the former rarely happens for silver’s sake, the latter takes many years [2] [5]. Industry pieces and forecasters stress that primary projects have long lead times (10–15 years is commonly cited) and that most near‑term growth comes from expansions at existing operations rather than quick greenfield additions [2] [3] [5].
3. Evidence that supply cannot quickly chase demand — deficits and inelasticity
Market reports document persistent structural deficits and plunging inventories even while prices rose sharply, a pattern consistent with supply inelasticity: deficits in recent years have been described as large (tens to hundreds of millions of ounces annually) and inventories like LME stocks at historic lows — signals that physical supply has been slow to respond to price signals [6] [7] [8]. Commentaries repeatedly point to the paradox that even big price moves only slowly change mine plans because most silver comes "for free" inside other miners’ output profiles [4] [8].
4. Practical limits: what higher prices can and cannot do quickly
Higher silver prices can accelerate certain responses — marginal increases in recycling, small expansions at flexible operations, and shifts in by‑product credit allocation — but these are incremental. Large swings in mined supply typically require new primary silver projects or substantial expansions of base‑metal mining capacity, both of which are time‑ and capital‑intensive and often constrained by permitting, ESG concerns, and falling ore grades [5] [9] [3]. Many analysts therefore argue that near‑term production elasticity is low: price signals alone are unlikely to eliminate structural deficits within a business cycle [2] [8].
5. Caveats, alternative views and the unknowns
Some sources emphasize degrees rather than absolutes: while the 70–75% by‑product figure is dominant in the reporting sample, estimates vary and depend on definitions (refined vs mined, co‑product accounting) and year‑to‑year swings in base‑metal output [1] [10]. Forecasters also note a path to greater supply over years via project ramp‑ups, new discoveries and secondary supply growth, meaning the constraint is strong but not immutable — it is structural and slow to unwind rather than an absolute blockade on future production [5] [3]. The reporting reviewed does not offer a unified, quantitative elasticity metric (e.g., percent supply response per dollar), so precise modelling of how fast supply could rise under specific price scenarios remains outside the scope of these sources [2] [5].