Mt Windsor

The Mt Windsor Joint Venture is an unincorporated joint venture between Grange’s wholly owned subsidiary, BML Holdings Pty Ltd (BML) 30% and Thalanga Copper Mines Pty Limited (“TCM”) 70%, the manager. The project comprises the Highway and Reward open pit copper mines; the Reward Deeps underground copper mine and exploration activities within the surrounding project tenements.

The project is located approximately 37 km south of Charters Towers in North Queensland.

Mt Windsor Project Location

The first mineralisation was discovered at Highway in 1953 when barite and gold mineralisation was exposed in a road cutting. Exploration by several companies over the next 30 years lead to a small open pit gold mine being developed in 1987 by North Queensland Resources. Subsequent exploration around the open pit by the first Mt Windsor joint venture resulted in the discovery of the Reward massive sulphide deposit by City Resources Limited in 1987 and the adjacent Highway massive sulphide deposit by Barrack Mines Limited two years later.

The Reward, Highway and Conviction deposits are composed of massive pyrite containing chalcopyrite in near vertical pipe like bodies cross cutting the host volcanic rocks. Exploration for additional massive sulphide deposits within the joint venture tenements is continuing.

Mining of copper ore from Reward commenced in 1998 and from Highway in late 1999. During this time exploration was successful in discovering a third massive sulphide pipe at Conviction to the south of Highway and also in delineating further deposits of copper mineralisation in the Reward pipe at North Reward and Reward Deeps. During 2001 the development of an underground mine was commenced to provide access to the Reward Deeps and Conviction deposits. Production of copper concentrates from the Reward Deeps project commenced at the end of October 2002.

Reward Deeps Mine – Location of Copper Deposits

 
Mining and milling operations ceased in July 2005 following the exhaustion of ore reserves.  Rehabilitation of the mine site has been completed and an environmental monitoring programme is ongoing.
Prior to the closure of the operation ore from the mine site was trucked 100km on sealed roads to TCM’s concentrator located at Thalanga, 60km due west of the mining operations.

Copper concentrate containing approximately 27.5% copper was then railed from Thalanga to Townsville for export.

Highway and Reward Open Pits and Portal to the Reward Deeps Underground Mine

The Reward deposit was mined by open pit during the period July 1998 to July 1999 and the project produced 165,000 tonnes of concentrate grading 29.1% copper and 3.2 g/t gold from 571,000 tonnes of ore grading 9.3% copper and 1.4g/t gold.

The Highway deposit was mined by open pit mined during the period November 1999 to March 2002 and the project produced 317,500 tonnes of copper concentrate grading 27.1% copper from 1.7 million tonnes of ore grading 5.5% copper.

The Reward Deeps and Conviction deposits were mined from underground and produced 200,300 tonnes of copper concentrate grading 26.3% copper from 1.4 million tonnes of ore grading 4.2% copper.