During the quarter, the company also extracted itself from its failed push into Thailand, selling its remaining 13% shareholding, or 19.1 million shares, in Thai zinc smelting company Padaeng Industry Plc at a profit.
Closer to home, WestMet officially ceased operations at its Hellyer lead-zinc mine in 80km south-west of Burnie, Tasmania.
“It’s now business as usual,” said managing director, Rod Webster. “It will pick up further in the next quarter and the one after that.”
Copper cathode production at Mt Gordon reached 10,308 tonnes for the quarter, a 42% increase on the previous quarter.
Although repairs to the main cellhouse rectiformer/transformer shut production down for seven days in the first week of June, plant availability average 92% and cash cost have fallen to below US40c per pound.
“Unfortunately, problems with the transformer have masked the true performance of the plant. The plant has been operating as wanted all year,” Webster said.
WestMet’s Lennard Shelf operations in Western Australia’s Kimberley produced a record 71,217t of zinc concentrates in the quarter, up from 64,319t in the previous period, despite the loss of a week’s production in April from Cyclone Rosita.
Mill production for the final quarter hit a record 652,429t with zinc recoveries increasing to 95.9%. Construction work on expansion of the mill at Pillara, one of WestMet's three Lennard Shelf mines, commenced in June.
With the Goongewa mine also scheduled to close in November, production at Pillara will increase to 1.8Mtpa to make up the shortfall.
WestMet plans to ensure it always has at least two mines feeding its central Pillara plant, which will give it much greater flexibility in getting new projects on the Lennard Shelf off the ground.
Exploration on the Lennard Shelf and at Mt Gordon finally got underway during the quarter after an extensive and late wet season.
The company has only recently been able to get onto its Fossil Downs ground, across the Margaret River to the north of Pillara. Webster said it is looking promising with drilling revealing several high grade intersections.
Drilling has confirmed that the Pillara resource now extends 250m north of the previous drilling.
Hole PD629 intersected three zones of mineralisation, with the best result being 5.95m grading at 11.4% zinc and 0.8% lead from a depth of 718.55m.
This drilling added 360,000t at 10.5% zinc and 0.7% lead to the inferred resource at Pillara.
Underground drilling has also continued on the northern extent of the F10 ore zone and has been successful at intersecting narrow high grade zones within the F10-B Lode structure. A total of 1.4 million tonnes at 16.4% zinc and 4.8$ lead has been converted to indicated resources by this drilling.
In the Mt Gordon area, drilling, regional mapping and sampling programmes tried to generate new targets on leases away from the Mt Gordon mine area.
Drill testing at the northern end of the Esperanza pit, Pluto area was successful in locating mineralisation along the strike of known mineralisation.
The mineralisation was sporadic native copper with chalcocite and cuprite in a strongly leached zone with haematite, chlorite and silica alteration. The best intersection that correlates with the Esperanza position was SD362, with 12.1m at 3.1% copper from 311m.
At the Mammoth lode, surface drilling confirmed E Lens grades and thickness.
