56km south of Kalgoorlie.
Located on the on the traditional lands of the Ngadju People of the Goldfields region of WA.
Figure - Long Operation - Regional geology, tenure, nickel shoots and targets.
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 3.2Mt of nickel ore, producing approximately 124,600t contained nickel through to June 2016. 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. The current life of mine plan supports the next 18 months.
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.
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.
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.
Production for FY16 came from the Moran, McLeay, Victor South and Long ore bodies. Total production was 215,300t of ore (FY15: 258,600t) at an average grade of 3.9% nickel for 8,493t of contained nickel.
Guidance for the Long Operation for FY17 is for production of between 7,400 and 8,200t of contained nickel at cash costs plus royalties of $3.50 to $3.90/lb payable nickel, net of copper credits. Sustaining capital and exploration expenditure are forecast to be $1 million and $2 to $3 million respectively.
Figure - Long Operation - Longitudinal Projection showing target areas, TEM conductors and significant intercepts
Drilling that targeted potential resource extensions at Moran South and McLeay South were ceased in December 2015, in line with the updated business plan which focused on the most profitable parts of the mine. No new resources or reserves were developed at Moran South or McLeay South.
During FY17 exploration at Long will recommence designed to continue to extend the life of mine.