Murrin Murrin Ni-Co Mine (Anaconda Nickel mine), Laverton Shire, Western Australia, Australiai

Regional Level Types
Murrin Murrin Ni-Co Mine (Anaconda Nickel mine)	Mine
Laverton Shire	Shire
Western Australia	State
Australia	Country

One of the largest nickel mines in Australia, this is a huge operation located approximately 60 kilometres west south-west of Laverton, on the north side of the Leonora to Laverton Road. The abandoned town of Murrin Murrin is some 10km to the SW.

Andrew (Twiggy) Forrest established Anaconda Pty Ltd with the express purpose of mining the deposit. The mine opened in 1999, but problems with the construction and operation of the processing plant beset the project from the very beginning. A new treatment process involving high temperature, high pressure use of sulphuric acid in autoclaves to leach the nickel and cobalt from the low grade oxidised ores was introduced. While this had worked well for many years in Cuba, the dry Western Australian clays clogged the plant, leading to the use of more acid than expected, resulting in corrosion and equipment failure.

By 2002, Anaconda had defaulted on its loans, and was restructured as Minara Resources Ltd. The mine's name changed from Anaconda to Murrin Murrin, and Glencore International AG came on-board as a partner.

The mine is different from the historic Anaconda copper mine, 12 kilometres to the south-west. This mine also changed its name to Murrin Murrin after a few years. (This mine is listed on Mindat under Anaconda). Numbered Murrin Murrin mine locations seen on maps are likely some of the many shallow pits as part of the mine complex. The last satellite image indicates 32 pits at the site, all shallow, irregular shaped, and close together. All are just north of the Leonora-Laverton Road except two which borders it to the south. New pits on rich nickel patches continue to multiply. There is little to indicate the geology of each differs markedly from this article.

The mineralisation is bounded and contained by a regional north plunging anticlinorium ( a large convex fold with superimposed smaller folds) to the east, and a synclinorium (as above but concave shaped) to the west. It is further influenced by regional north north-east striking westerly dipping fault off-shoots of the Keith-Kilkenny Fault to the south-west. Deformation caused by granite, granodiorite, and adamellite intrusions resulted in outcropping of serpentinized peridote at the main mine, Murrin Murrin North, and another deposit south of the main road at Murrin Murrin South.

There is 10 metres of overburden before the mineralized ore, which can be described in three zones, each 10 metres thick.

From the ultramafic base upwards, the first is a saprolite zone dominated by serpentine, with saponite, Mg chlorite and localised magnesite.

Next is the smectite zone, which is the most prominent of the three zones. Its colour ranges from dark green to bright apple green to chocolate brown, and locally black where Mn oxides are abundant. It is 90% smectite with minor chlorite, serpentine, goethite, hematite and Mn chromium oxides. Nontronite, beidellite and montmorillonite is also found here.

Lastly is a ferruginous zone of kaolinitic clays towards the base, and upper levels containing a hardcap of iron oxides, goethite, hematite and Mn oxides, with locally capped calcrete, magnesite, silcrete, and gypsum.

Cobalt is largely restricted to the Mn oxides, at or near the contact between the smectite and ferruginous zones. The highest concentrations of nickel is found in the smectite and upper saprolite zones, mainly in smectite clays and chlorite.

Localities in this Region

Other Regions, Features and Areas containing this locality

References