The Hellyer mine, near Waratah in western Tasmania, was opened in 1989 on a blind ore body discovered in 1983. The ore was concentrated on site, with the concentrates railed to Burnie for shipment. Mine development began in 1987, with the concentrator commissioned in 1989. The concentrator operated for about 11 years running at 1.5 million tonnes per annum capacity until mine closure in June 2000. During the eleven years of mining at Hellyer the ore body yielded more than 15Mt of ore from which 2.7Mt of zinc concentrate, 728,000t of lead concentrate and 601,000t of bulk concentrate were produced. The mine generated about $1.3 billion in gross revenue.
Feasibility studies were later undertaken, and a demonstration plant constructed, to assess the viability of mining tailings from the earlier operations. A total of 1.129Mt of tailings were mined during 2007 and 2008 to produce 52,600t of concentrate containing 19,200t of zinc, 6600t of lead and 10 kilograms of silver. The tailings retreatment ceased in late 2008 and the mill was sold to Bass Metals.
The tailings comprise about 11Mt of material grading three per cent zinc and 2.7 grams per tonne of gold.
The current Hellyer Mine Project (HMP) comprises the Hellyer remnant resources and the adjacent Fossey Zone prospect. Construction of the new underground mine at the Fossey deposit began in January 2010.
The Hellyer deposit is a single high grade polymetallic volcanic hosted massive sulphide ore body with the pre-mining mineral resource originally reported as being 17Mt grading 14 per cent zinc, seven per cent lead, 0.4 per cent copper, five ounces per tonne of silver and 2.5g/t of gold.
Operating. In November 2011 Bass Metals reported that ore production from the Fossey underground mine for the financial year had achieved budgeted levels in terms of tonnage and was consistently better with respect to grades of all payable metals.
The sixth milling campaign began on October 3, 2011 and concluded on October 31, 2011, having processed about 67,000t of ore, including a small proportion of spillage reclaim.
To date about 5000t of zinc and 1500t of lead concentrates had been trucked to the Burnie port with trucking operations ongoing. Preparations were underway to ship the next consignment of copper-precious metals concentrates in containers to Bass Metals' off shore customer.