Tag Archives: nickel

Zenith Energy helps Independence go solar at Nova nickel-copper operation

Independence Group’s Nova nickel operation is set to play host to Australia’s first fully-integrated commercial hybrid diesel/solar photovoltaic (PV) facility after the company signed a contract amendment with remote power generation specialist Zenith Energy.

The changes to the existing power purchase agreement, signed by Zenith and Independence back in 2015, will incorporate a solar PV facility with a forecast 12.5 GWh/y.

Zenith’s subsidiary, Zenith Pacific, will now build, own and operate a hybrid diesel/solar PV power station of around 26 MW in installed capacity to “reliably and efficiently service the power needs of the Nova operation”, the company said.

Zenith has made huge strides since becoming a public entity via the ASX in May, sealing contracts with the likes of Gascoyne Resources, for its Dalgaranga gold project, and Dacian Gold, for its recently opened Mt Morgans gold mine.

Managing Director of Zenith Energy, Hamish Moffat said: “This development represents the first fully integrated and commercial hybrid diesel/solar PV facility in Australia and is a step forward in future renewable energy solutions.”

The solar PV will include “state-of-the-art PV modules, single axis tracking, inverters, communications and control system technology”, Zenith said.

The hybrid power station will incorporate high efficiency diesel-fuelled generators and solar PV generation.

The integrated facility is expected to be completed within the first quarter of Zenith’s 2020 financial year (to end-June, 2020). The initial supply period is for six years with an option for Zenith to extend for a further two years.

Independence Group’s Managing Director, Peter Bradford said: “The development of this innovative hybrid energy solution will…improve our cost structure with targeted renewable power insertion of up to 50% of demand via the solar PV facility.”

Nova is in the Fraser Range of Western Australia, some 160 km east-northeast of Norseman. It produced 22,258 t of nickel and 9,545 t of copper in its first full year of operation in the 2018 financial year.

Ivanhoe Mines’ Platreef Shaft 1 intersects ‘Flatreef’ PGM deposit

Ivanhoe Mines and sinking contractor Aveng Mining have reached a new milestone at its Platreef PGM-nickel-copper-gold project in South Africa with Shaft 1 now at the top of the ‘Flatreef’ deposit, 780 m below surface.

At the Shaft 1 intersection, the flat-to-gently-dipping deposit is an estimated 26 m thick, making it amenable to the sort of bulk-scale mechanised mining most PGM operators would dream of.

This is the first time Platreef, in the Northern Limb of South Africa’s renowned Bushveld complex, has been intercepted by underground mining activity, according to Ivanhoe Mines.

The mining team has now delivered first ore from the underground mine development to a surface stockpile for metallurgical sampling. “The estimated thickness of the mineralised reef (T1 and T2 mineralised zones) at Shaft 1 is 26 m, with grades of platinum-group metals ranging up to 11 g/t 3PE (platinum, palladium and rhodium) plus gold, as well as significant quantities of nickel and copper,” the company said.

The 26 m intersection is expected to yield some 3,000 t of ore, estimated to contain more than 400 oz of PGMs.

The 750 m station on Shaft 1 will provide initial, underground access to the orebody, enabling mine development to proceed during the construction of Shaft 2 – the mine’s main production shaft.

The mining zones in the current Platreef mine plan occur at depths ranging from approximately 700 m to 1,200 m below surface.

Shaft 1’s 750 m station will also allow access for the first raisebore shaft, which will have an internal diameter of 6 m, to provide ventilation to the underground workings during the mine’s ramp-up phase.

As shaft-sinking advances, two additional shaft stations will be developed at mine-working depths of 850 m and 950 m. Shaft 1 is expected to reach its projected, final depth of 980 m below surface, complete with the stations, in early 2020.

Shaft 2

Excavation of the Shaft 2 box cut to a depth of approximately 29 m below surface is progressing well, according to Ivanhoe.

Completion of the box cut will allow for the construction of the concrete hitch (foundation) for the 103 m-tall concrete headframe that will house the shaft’s permanent hoisting facilities and support the shaft collar.

Shaft 2, around 100 m northeast of Shaft 1, will have an internal diameter of 10 m, will be lined with concrete and sunk to a planned, final depth of 1,104 m below surface. It will be equipped with two 40 t rock-hoisting skips with a capacity to hoist a total of 6 Mt/y of ore. This is the single largest hoisting capacity at any mine in Africa, according to Ivanhoe.

Headgear for the permanent hoisting facility was designed by South Africa-based Murray & Roberts Cementation.

In July 2017, Ivanhoe issued an independent, definitive feasibility study (DFS) for Platreef covering the first phase of production at an initial mining rate of 4 Mt/y. The DFS estimated Platreef’s initial, average annual production rate would be 476,000 oz of platinum, palladium, rhodium and gold, plus 21 MIb (9,525 t) of nickel and 13 MIb (5,897 t) of copper.

Vale Canada set for Sudbury emissions cut with Clean AER operation

Vale’s Sudbury, Canada, operations are set for an 85% reduction in sulphur dioxide emissions after the Brazil-based company completed its C$1 billion ($792 million) Clean AER (Atmospheric Emission Reduction) project.

The project is the largest single environmental investment in Sudbury’s history and, on top of the sulphur dioxide emission cut, will also see metal particulate emissions come down 40%, according to Vale.

Work began on the project in 2012 and included the construction of two new converters, a wet gas cleaning plant, a new secondary baghouse and fan building and reconstruction of the smelter converter flues. Due to close coordination between the project and operations, this construction took place safely while the Copper Cliff smelter continued to operate.

Ricus Grimbeek, Chief Operating Officer of Vale’s North Atlantic Base Metals Operations and Asian Refineries, said: “The completion of our Clean AER project is a historic milestone that demonstrates how far we have come as a company in reducing our environmental footprint.”

Emissions are set to come down so significantly with the project that Vale’s Sudbury operations will no longer require its iconic “Superstack”, according to Dave Stefanuto, Vale’s Vice President of North Atlantic Projects.

The Superstack is the tallest chimney in Canada and the Western hemisphere, measuring in at 380 m. It entered full operation in 1972.

Two new 137 m stacks are currently being constructed in the Copper Cliff smelter, which will require far less energy to operate than the Superstack and reduce greenhouse gas emissions from the smelter by some 40%, Vale said. Following construction of the concrete shells, steel liners will be installed in the new stacks in 2019.

In 2020, the Superstack’s steel liner will be removed and the Superstack will be taken out of service and placed on care and maintenance. It is expected that removal of the concrete shell will begin thereafter and continue over several years.

Vale’s operations in Sudbury are home to one of the largest integrated mining complexes in the world with five mines, a mill, a smelter and a nickel refinery.

Former Talvivaara nickel mine on the rebound under Terrafame

The former Talvivaara nickel mine in central Finland is back in the black and looking to new developments four years after the previous owner went bankrupt.

Operating under Terrafame, majority owned by the Finnish government through the Finnish Minerals Group, the mine is finally making good on its early promise.

On a site visit to the mine this week, part of the Finland Mine Safari programme for analysts and investors, CEO Joni Lukkaroinen talked about getting back to planned capacity of 35,000 t/y of nickel, 75,000 t/y of zinc, 1,400 t/y of cobalt and 5,000 t/y of copper.

The company hasn’t set out to change any major part of the process flowsheet to do this – it is still using a two-stage bioheapleaching process to produce a nickel-rich pregnant leach solution that is precipitated as sulphides in the plant – but it has refined the operations Talvivaara started up almost a decade ago.

On top of this, the company is looking to bolt on a hydrogen sulphide line that could see the company produce 170,000 t/y of nickel sulphate and 7,400 t/y of cobalt sulphate for the emerging electric vehicle battery market, in addition to 115,000 t/y of ammonium sulphate for fertilisers.

And, it also has a near-completed uranium plant that could potentially produce yellowcake in the medium term should it receive an environmental permit from the relevant authorities.

Talvivaara may be best known for the gypsum pond leak that occurred in late 2012 and saw nickel, uranium and other toxic metals go into the nearby environment, but even before this event led Talvivaara Sotkamo to eventual bankruptcy, it was struggling to achieve the production numbers it had previously forecast as the bioleaching process that justified mining the low-grade ore got the better of it.

Terrafame, which was formed in 2015 specifically to turn the operation around, has already surpassed the former owners’ production record and, earlier this year, started generating postive earnings.

EBITDA excluding work in progress (ore within the leaching pads) came in at a slim €1.6 million ($1.85 million) in the March quarter and more than doubled to €3.3 million in the most recent June quarter.

This is some change from the -€33.3 million and -€24.2 million the company posted in the same periods a year earlier.

Improved year-on-year metal prices have helped this recovery, but the company has also gone from producing 9,791 t and 4,787 t of zinc and nickel concentrate, respectively, in the March quarter of 2017, to a record 15,008 t of zinc and 6,421 t of nickel in the same quarter of 2018.

While these numbers are still some way off full capacity, they are significantly more than the circa-14,000 t per quarter Talvivaara produced at its peak.

There was at least one obvious change to the process Talvivaara set up when IM visited – Terrafame is now using Wirtgen surface miners to improve the material feed that is stacked and reclaimed from the leach pads and moved onto the metals plant – but the improvement in performance has been achieved through several tweaks, according to Lukkaroinen.

He told IM that the company has, among other things, put much more emphasis on improving the agglomeration of the ore, ensured the material on the leachpad is effectively aerated during both leaching stages and monitored the temperature of the exothermic process much more closely. The latter, in particular, is very important in judging success of the leaching.

This is really now starting to pay dividends during the 50 months, combined, the ore sits on the primary and secondary leach pads.

It has also given the company confidence to invest in a hydrogen sulphide plant that could see the company increase its exposure to the EV battery market.

As it stands, the company already sells around 50% of its nickel concentrate to this market, but the production of nickel and cobalt sulphates is likely to see the company retain more value for its product and provide further sales opportunities.

The fully-financed sulphide plant build will take some two years to construct, with start up, subject to regulatory approvals, planned for the second half of 2020. The company is just months away from awarding the major contracts for the construction.

The process, already proven on a commercial scale, will see nickel-cobalt sulphide from the existing production plant processed in an autoclave, before nickel cobalt and impurities are extracted. It will finally move on to a crystallisation phase where two separate sulphate products are produced.

The 170,000 t/y nickel capacity would make the company one of the biggest sulphate producers in the world.