The King Island Scheelite project is near the town of Grassy, on the south east coast of King Island, the most western large island in Bass Strait.
This resource comprising Dolphin, Bold Head and Tailings deposits of 9,109,000 tonnes containing 81,720 tonnes of WO3. The proposed redevelopment involves reopening the former underground mine at Dolphin and constructing a processing facility to produce approximately 3,500 tonnes of WO3 concentrate per annum.
Proposed Development Overview
The former mine at Dolphin was run as an open pit up until 1975, and as an underground mine until closure in 1990, due to WO3 concentrate trading as low as US$5,000/tonne. The underground operation at nearby Bold Head also closed at this time. All equipment was removed after closure, the pit allowed to flood, and the site fully rehabilitated. The improved concentrate prices (US$32,500/tonne in February 2012) and remaining resource support a redevelopment.
The potential here is to develop a commercial project accessing the Dolphin resource via former underground workings and feeding a new processing facility with appropriate infrastructure. Reopening the Bold Head mine as well as the potential to access further tonnes below Dolphin workings are opportunities to add further value to this project.
The resource estimates are JORC (2004) compliant.
Dewater the former mine and rehabilitate the existing decline from the base of the old pit. A contractor will be engaged to operate the underground mine producing 350,000 tonnes of ore per annum using post-pillar stoping method with classified tailings for hydraulic fill.
This underground development removes the need for constructing sea and a cut-off walls previously envisaged to protect an open pit development from water ingress, thus removing substantial uncertainty and cost.
Reopening Bold Head is an opportunity which together with retreating tailings provide additional cash flow with minimal additional infrastructure.
Extension down plunge at Dolphin could provide substantial additional tonnes.
The Dolphin Project plans to construct a processing plant with annual capacity of 300,000 tonnes. Following successful metallurgical test work conducted in China. A flow sheet and mill design has been developed based on whole ore flotation techniques with positive mill performance and cost outcomes.
This mill will produce approximately 3,500 tonnes of 65% tungsten concentrate per annum. This product will be shipped to customers in "bulka bags" inside conventional shipping containers. This is expected to represent more than 5% of world tungsten supply and up to 25% of global supply outside China.
The plant will be established close to the pit, at the bottom of the Lower Grassy Dam.
A tailings dam will be built on the site of the previous dam.
King Island is positioned mid way between Victoria and Tasmania, and is well serviced by sea and air transport. The main deep water port for the island is located approximately 1 km from the mine site, and the airport is less than 30 minutes away by sealed road.
It will be necessary to provide additional power, as the island's existing supply is insufficient to meet the project's needs. The project team developed acceptable solutions to provide power.
The township of Grassy is largely privately owned. The Dolphin Project does not intend building extensive staff housing, but has the potential to access a variety of appropriate accommodation arrangements for mine personnel.