Henty

Unity Mining, formerly known as Bendigo Mining, saved Tasmania from losing its last operating gold mine when it acquired Henty from Barrick Gold in 2009. The only other gold mine in the state, Beaconsfield, had already flagged closed following a tragic rock fall and dwindling economical gold resources.

Barrick Gold was Prepared to Close up Shop and Walk Away From Their Henty Operation

Barrick gold, the world's largest gold producer, had also intended to walk away from the Henty Gold mine, until the Tasmanian government became involved which resulted in an impending closure being turned around to one of sale to another gold miner. The buyer being Unity Mining who, in taking up the Henty acquisition, saved the jobs of 180 workers. The workers welcomed the new ownership after being subjected to five ownership changes in the previous 16 years the mine had been operating. They were impressed that the mine finally had an owner willing to supply the equipment necessary to see it experience growth.

A Gold Mine Among Glaciated Mountain Ranges

Since the Henty Gold Mine opened in 1996 it has produced up to 1.3 million ounces of gold, despite only being given a life of mine expectancy of five years at the time. It is located in one of the most picturesque areas of the island among glaciated mountain ranges adjacent to the Tasmanian South West Conservation Area, 10 kilometres from Rosebery and 19 kilometres from Queenstown.

Access to Henty via Decline or Shaft

Access to the underground operations, containing over 100 kilometres of tunnels, to a depth of 800 metres, is obtained via a decline and shaft. Mining methods vary depending the geometry of the ore body being worked at the time but the most common method used is traditional long hole bench stoping, cut and fill (flat backing) and transverse open stoping. Mullock or paste fill is used to fill stopes. There is also a processing plant on site that can handle 300 thousand tonne of ore a year. The plant consists of a conventional CIL plant, gravity circuit, SAG mill and static grizzly.

Gold Refining Process at Henty

During the processing operation a substance that looks very much like sand is smelted to 1,500 degrees Celsius. It is then leached with cyanide when it becomes a liquid and poured into a rectangular container. Here it is allowed to settle, cooled down with water, brushed, and a 50/50 silver/gold dore bar the size of the average book emerges. This bar weighs approximately eight or nine kilograms and is valued at around $235,000.

Mining Leases Cover 160 Square Kilometres

The Henty Gold Mine came with six exploration and two mining leases covering an area of around 160 square kilometres. These leases cross the South Henty, North Henty and Great Lyell Faults which are all highly prospective with great mineral potential that already host the Rosebery, Mount Lyell, Hercules, Que river and Hellyer base metal deposits. The company employs 12 geologists who are continually working to expand the mining operation, buy more leases and keep up the search for more gold. Exploration in this way costs the company $10 million annually.