Zinc smelters bleed as TC crisis deepens: $85 benchmark and negative spot charges squeeze margins to the bone

The numbers tell a grim story for zinc smelters. In March 2026, Canadian miner Teck Resources and Korea Zinc agreed on the annual benchmark zinc concentrate treatment charge (TC) of US$85 per tonne — essentially flat from the 2025 record low of $80/t and down from $165/t in 2023 and $274/t just four years earlier. For context, treatment charges represent the fee miners pay smelters to convert concentrate into refined metal. The contraction reflects a structural shift: concentrate supply has recovered, but smelter capacity — particularly in the West — has not kept pace. (FACT: Fastmarkets, March 6, 2026; Reuters, April 2024)

Spot market conditions are even worse. Fastmarkets assessed the cif China zinc spot concentrate TC at $10–50 per tonne in late February 2026 — flat from earlier assessments but far below the benchmark itself. By May 2026, Chinese import spot TCs had compressed further to approximately $15–28 per dry metric tonne, according to market sources. High-quality material from Antamina (the massive Peruvian copper-zinc mine) has reportedly traded at negative TCs of -$40 to -$65 per dry metric tonne, meaning smelters are effectively paying miners to take their concentrate — an extraordinary inversion of normal market mechanics. (FACT: Fastmarkets, February 2026; SMM, May 2026; Metalnomist)

Smelters are increasingly dependent on by-product revenues to stay afloat. With the primary revenue stream from zinc treatment charges near zero or negative, smelters must extract value from the precious metals (silver, gold), minor metals (germanium, antimony, bismuth, indium), and other payables contained in complex concentrates. The evolving TC negotiation now involves detailed discussions of payable formulas — what percentage of silver, germanium, and other by-products the smelter can keep. As one source told Fastmarkets: "If payables are evolving, that's not exactly an increase in the [benchmark] terms. It's just changing how terms are charged." (FACT: Fastmarkets, March 6, 2026)

The result has been an implosion in Western smelter profitability. Reuters described zinc smelter charges turning negative in late 2024, recovering only to about $55/t by mid-2025 — still below the (then-record-low) 2025 benchmark of $80/t. High energy costs in Europe compound the problem; several European smelters have closed or reduced output since the energy crisis of 2022. The Australian government has faced urgent calls to save Nyrstar's zinc and lead smelters. (FACT: Reuters, July 3, 2025; Reuters, May 2026)

This smelter margin crisis is the hidden driver of zinc's supply deficit. The obvious narrative focuses on mine supply, but the real bottleneck is at the smelting stage. Global mined zinc production surged 4.8% in 2025 after three years of contraction — there is no shortage of concentrate. But smelters cannot, or will not, process it at these margins. The ILZSG notes that outside China, refined output actually contracted in 2025. Low TCs, not mine closures, are why. (FACT: ILZSG, April 2026; Reuters, May 20, 2026)

China's smelters are in a different position. Despite the low global TC environment, Chinese smelters have expanded aggressively, boosting output 6.7% in 2025. China's concentrate imports rose 30% year-on-year to 2.58 million tonnes as the country absorbs a growing share of global concentrate. But even Chinese smelters are feeling the pinch — domestic TC levels in yuan terms have been declining steadily, with SMM's Zn50 domestic TC falling 150 yuan/mt week-on-week in mid-May. (FACT: SMM, May 2026; Metalnomist)

The Kazzinc and Cajamarquilla disruptions add acute operational risk to the chronic margin problem. Neither incident was caused by TC economics — but in a sector where margins are already razor-thin, there is little buffer for unplanned downtime, repair costs, or the investment needed to improve safety infrastructure. The structural fragility of Western smelting means every operational incident carries outsized market impact. (FACT: Reuters, May 2026; Glencore, Nexa Resources statements)

The TC crisis is not a cyclical dip. It reflects a permanent shift in the industry structure: China controls nearly 50% of global refined zinc production and is adding more capacity, while Western smelters struggle with legacy assets, high costs, and no margin incentive to invest. Until TCs recover to levels that support reinvestment — historically $200–300/t — the Western smelter bottleneck will persist, and the zinc market will remain structurally tight.