The waiver, first implemented in August 2025, allowed miners to export up to 271,742 tonnes of copper concentrate duty-free while domestic smelters were offline, according to a government notice seen by Reuters in June. Mopani Copper Mines held the largest quota under the waiver, at 100,000 tonnes, while KCM held 12,541 tonnes, according to the notice.

KCM resumed operations at the Nchanga smelter after a shutdown that ran 46 days longer than initially scheduled, the company said on Monday September 21. It had signed a $498 million contract with China Nerin Engineering for a 70,000-tonne-per-year tailings leach plant four days earlier, according to company statements.

The Nchanga smelter was built at a cost of $350 million and commissioned in 2010. It has capacity to produce 311,000 tonnes of copper. The shutdown was initially scheduled to last 60 days, but detailed inspections identified additional critical work, KCM said.

The rehabilitation cost about $40 million and was the smelter’s first major refurbishment in eight years, the company said. In late May, KCM described the shutdown as its first major smelter maintenance in five years.

KCM signs contract with China Nerin Engineering for tailings leach plant
KCM signed the engineering, procurement and construction (EPC) contract with China Nerin Engineering on September 17 for a tailings leach plant at its operations in Chingola, Mining.com.au reported.

The plant would use hydrometallurgical processing to recover copper from existing mine tailings and would have an annual production capacity of about 70,000 tonnes, according to the report.

KCM described the facility as Africa’s largest copper tailings leach plant, a claim that could not be independently confirmed.

China Nerin’s scope covers design, equipment procurement, construction, installation and commissioning, as well as technical support, performance testing and workforce training.

The new plant would operate alongside KCM’s existing tailings leach plant at Nchanga, Business Insider Africa reported.

KCM has not disclosed a construction timetable, an expected commissioning date or how the plant will be financed.

KCM said in a statement that the plant adds to Vedanta’s $1 billion investment in KCM, which includes the Konkola Deep Mining Project. Deputy Chief Executive Officer Satish Kumar described the project as a major milestone in the company’s growth, according to local media reports.

Acid availability the constraint: trader
A trader source said the bottleneck for KCM’s leaching operations had been sulfuric acid availability from its captive smelter.

“This is for their tailings leach plant, which leaches their mixed refractory ores, but the bottleneck here has always been their captive smelter acid availability, which in turn is a function of their own mine output [from Konkola and Nchanga],” the trader said.

The trader said the involvement of a Chinese contractor was a positive signal, but that they did not expect the project to have a material influence on the copper concentrates market.

Andy Cole, Fastmarkets’ principal analyst, said KCM’s progress was still some distance from its production goal.

“It’s a step in the right direction and demonstrates Vedanta’s commitment, but there is a long way to go to reach Vedanta’s target for KCM of 300,000 tonnes per year by 2030. These are challenging operations that have suffered from a lack of investment for some years.”

Production targets
KCM produced 80,215 tonnes of copper in 2025, according to Zambia’s Mines Ministry.

KCM said the smelter maintenance was part of a broader modernization strategy aimed at lifting output toward 300,000 tonnes per year by 2030, according to Reuters. CopperTech Metals (a subsidiary of Vedanta Resources) said in June that it aimed to raise integrated production to 300,000 tonnes per year by 2031, from 140,000 tonnes in 2026.

Zambia, Africa’s second-largest copper producer after the Democratic Republic of Congo (DRC), aims to raise national output to 3 million tonnes per year by 2031, from 890,346 tonnes in 2025.

KCM is 79.4% owned by CopperTech Metals, a subsidiary of Vedanta Resources, while ZCCM Investments Holdings holds the remaining 20.6%. The latter is a Zambian state-backed mining and investment holding company that manages the government’s strategic equity stakes in the country’s mining and energy sectors

Zambian smelter outages and acid supply
Two other large Zambian smelters had planned maintenance during the same period. Mopani was scheduled to shut its Mufulira smelter for about 40-45 days between August and mid-September, a mining executive told Reuters in April, while China Nonferrous Mining Corporation’s (CNMC) Chambishi smelter was scheduled to close for about two months through August, according to the same report.

Fastmarkets could not confirm whether the shutdowns went ahead as scheduled or whether the smelters have since restarted.

When the shutdown began in late May, KCM said it would continue supplying acid to its Nchanga tailings leach plant from external sources and from its own 500-tonne-per-day acid plant.

KCM said on September 21 that the rehabilitation had included work on the sulfuric acid plant’s heat exchanger and on the wet and dry electrostatic precipitators, but it did not say whether acid production had resumed or how output would be allocated.

KCM did not respond to Fastmarkets’ request for comment by the time of publication.

Fastmarkets calculated the weekly copper concentrates treatment charge (TC) index, cif Asia Pacific — the midpoint between smelter and trader buying levels — at $(267.40) per tonne on Friday September 25, down by $3.60 per tonne from $(263.80) per tonne on September 18.

The copper concentrates TC implied smelters purchase, cif Asia Pacific, was calculated at $(233.90) per tonne on the same day, down by $3.60 per tonne from $(230.30) per tonne on September 18.

The copper concentrates TC implied traders purchase, cif Asia Pacific, was calculated at $(300.90) per tonne on September 25, down by $3.60 per tonne from $(297.30) per tonne on September 18.

From: Fastmarkets, 30 SEPT 2026.