SMELTING AND REFINING COSTS Copper concentrate smelting and refining costs are being negotiated with a 30% increase, in LME; rumors indicate that those of zinc would rise something of 40%.
But the price of zinc could rise more than that %.
They are already talking about a deficit of zinc production levels of 100k/150k per quarter in 2022.
https://www.metalbulletin.com/Article/4021127/Citi-predicts-global-zinc-market-deficit-of-over-100000-tonnes-in-Q1-2022.html