JOHANNESBURG (miningweekly.com) – Diversified miner Vedanta Resources' Zinc International business recorded a 25% year-on-year decrease in production to 32 000 t  for the quarter ended June 30 – the first quarter of its 2018 financial year.

The decrease was mainly as a result of an planned plant shutdown at the acid plant, as well as lower recoveries at the Skorpion zine mine, in Namibia, in June, the company reported on Wednesday.

Production at Skorpion during the quarter was 42% lower year-on-year and 36% lower quarter-on-quarter at 14 000 t.

Mined metal content production for the quarter was 4% lower year-on-year and 7% lower quarter-on-quarter to 18 000 t, largely as a result of lower feed grades.

GAMSBERG
Meanwhile, first production from the Gamsberg zinc project, in the Northern Cape, in South Africa, remains on track for mid-2018, with the project progressing well, the company reported.

Pre-start activities and waste-stripping at the project have progressed well, with the completion of the north access ramp, which is a critical milestone and part of the openpit development, achieved to schedule. The north pit prestripping also fully ramped up in the first quarter.

To date, Vedanta has excavated more than 22.5-million tonnes of waste rock. All major orders for the integrated process plant, water and power, mining and other prestart activities have already been placed.

Manufacturing of critical machinery such as the mills, crusher and transformers is progressing well. Major contractors have been mobilised to the site, with site activities including civil works, power lines and water lines under way.
 
The first phase of the project is expected to have a mine life of 13 years, replacing the production lost by the closure of the Lisheen mine, in Ireland, and restoring Zinc International’s volumes to more than 300 000 t/y. There is also significant potential for further optimisation at the Gamsberg North deposit.

At Skorpion, the Pit 112 extension project is also progressing well, with most equipment in place. Waste mining started in April.

The extension project involves a pushback of the high wall of the existing pit and will increase the mine life from 0.5 years to three years. It will also increase current reserves from 900 000 t, at 6.5% grade, to 4.2-million tonnes at 9.9% grade. 

Vedanta expects production volumes to be around 160 000 t/y in the 2018 financial year. 

ZAMBIA COPPER
Vedanta’s Zambia copper operations, meanwhile, achieved a production improvement at the Konkola underground copper mine and the Nchanga openpit, with integrated production up 9% quarter-on-quarter.

Mined metal production was up by 35% quarter-on-quarter to 20 000 t during the period. This was as a result of improvement in equipment availability at the Konkola mine, increased throughput at the Nchanga operations and an improvement in tailings leach plant (TLP) availability. 

Fleet availability at the Konkola mine further improved to 53% in the current quarter, compared with 23% in the previous quarter.

Productivity improvements at the Nchanga openpits, in addition to concentrator plant availability of 88% and TLP availability of 86%, led to integrated production of 8 000 t in June, with the trend having continued into July.

Mined metal production was, however, 30% lower year-on-year, mainly as a result of lower equipment availability at Konkola mine and availability at TLP compared with last year. This has now improved significantly, according to Vedanta.
 
Custom volumes were 56% higher year-on-year to 27 000 t, owing to improved third-party concentrate availability and the company’s ability to handle feed rates greater than 70 t/h at the smelter, following the biennial shutdown during the third quarter of the 2017 financial year.

Custom volumes, however, fell by 17% quarter-on-quarter as a result of relatively lower availability of local concentrate. 

Vedanta CEO Tom Albanese noted in a statement released on Wednesday that Vedanta was working to optimise costs at its Zambia Copper operations.

Vedanta further reported that Phase 1 of the elevated temperature leaching project targeted at improving TLP recoveries is under stabilisation, with the company in the process of appointing an engineering consultant for Phase 2.

Meanwhile, construction of the heap leach pilot test pads is progressing well, with commissioning expected before the third quarter of the current financial year.

Further, preliminary proposals have been received on the cobalt project and the identification of an offtake and techno-economic partner through a request for proposal-led process is under way. This is expected to be completed before the third quarter of the 2018 financial year.
 
Water levels at the Kariba dam are also improving and currently sit at 56%, compared with 34% in the previous year.

Power cuts in the country have been stopped; however, the force majeure declared by State-owned power supply company Zambia Electricity Supply Corporation and Copperbelt Energy Corporation continues.

Further, Reuters on Wednesday also reported that operations at the Nchanga underground mine would be halted indefinitely owing to the theft of high-voltage electricity distribution cables.

Meanwhile, Vedanta expects its integrated production to reach 95 000 t to 110 000 t for the full year, while custom smelting production is expected to be between 80 000 t and 90 000 t.