Long Operation

Ownership
IGO 100%

Location
56km south of Kalgoorlie.

Located on the on the traditional lands of the Ngadju People of the Goldfields region of WA.

Long Operation - Regional geology
Figure - Long Operation - Regional geology, tenure, nickel shoots and targets.

Background and History

IGO acquired the Long Operation, from BHP Billiton Nickel West Pty Ltd (formerly WMC Resources Ltd) in September 2002. The mine was successfully re-commissioned in October 2002 and has been operating successfully and safely since then. Since October 2002, IGO has produced over 3.4Mt of nickel ore, producing approximately 133,000t contained nickel through to June 2017. Over the period, exploration has seen the discovery of the McLeay (2005) and Moran (2008) ore bodies and historically enabled the operation to maintain a reserve base to support a two to three year mine life. Based on current life of mine plans, the Long Operation will reach the end of its Ore Reserves and cease mining operations towards the end of FY18. The Company currently expects the mine will go into Care and Maintenance and to continue exploration.

Geology

The Long Operation comprises approximately 1,830km2 of tenements stretching 7.5km in strike length along the eastern flank of the Kambalda Dome in the South Central portion of the Archaean Norseman-Wiluna Greenstone belt of the Yilgarn Craton. The Kambalda Dome is a double-plunging antiform with a core of granodiorite flanked by meta-tholeiitic basalt which is overlain by komatiite and intercalated chemical sediments. The host rocks and associated contacts have been subjected to lower amphibolite metamorphism, structural modification, and intrusion by multiple felsic to intermediate igneous dykes.

The “world class Kambalda Sulphide Nickel” orebodies are associated with Achaean ultramafic lava channels where molten liquid nickel sulphides pooled at topographic lows along the komatiite channel. Subsequent folding has rotated the channels from 30° to vertical dip to the east, 10° plunge to the south as well as resulting in the remobilisation of some of the original sulphides into new structurally imposed positions. The sulphidic nickel ore bodies are narrow, ribbon like accumulation of massive to semi-massive sulphides to disseminated sulphide ore up to 12m thick.

Mining

The Long Operation is an owner operation mechanised underground mine that primarily uses long-hole open stoping and long-stoping with backfill. Mining is carried out using a fleet of 1700 & 1300 Caterpillar Load Haul Dumps and 45t & 50t Caterpillar trucks. Ore is hauled to surface by truck to ore stockpiles and then transported ~1km to the nearby BHPB Nickel West concentrator for processing.

Offtake Agreement

IGO has an agreement with BHPB Nickel West whereby the ore produced from the mine is delivered to the adjacent BHPB Nickel West, Kambalda Nickel Concentrator for toll treatment and production of nickel concentrate. The current offtake agreement expires in 2019.

FY17 Production

In FY17, production came from the Moran, McLeay, Victor South and Long ore bodies. Total mining was 205,372t of ore (FY16 215,377t) at an average grade of 4.11% Ni for 8,433t of contained nickel. 

Long successfully achieved better than guidance performance on production and costs in all four quarters of FY17. This was a result of the dedicated effort by the team who worked diligently to consistently meet production requirements.

FY18 Guidance

Guidance for the Long Operation for FY18 is for production of between 5,400 and 6,000t of contained nickel at cash costs plus royalties of $4.40 to $4.90/lb payable nickel, net of copper credits. Sustaining capital and exploration expenditure are forecast to be $0.5 to $1 million and $1 to $2 million respectively.

Long Operation - Longitudinal Projection showing target areas
Figure - Long Operation - Longitudinal Projection showing target areas, TEM conductors and significant intercepts

Near Mine Exploration

During FY17, reprocessing and reinterpretation of 3D seismic data has resulted in the development of a number of exploration targets at Long. These targets will be tested as part of the FY18 exploration program.