Ernest henry

The Ernest Henry Mine is an underground operation that mines and processes magnetite, gold and copper. The mine is located in North West Queensland 38 kilometres from Cloncurry on the cattle property, Fort Constantine. Fort Constantine is the cattle station developed by Roger Sheaffe on which his friend and prospector, Ernest Henry, discovered a number of rich ore bodies in 1866.

GlencoreXstrata First Mined the ore Body as an Open Pit

Glencore's Ernest Henry mine commenced commercial production in March 1998 as an open cut operation. Underground mining began at the site in December 2011 as part of the company's $589 million upgrade to extend the life of the mine to around 2024.

Ore now Trucked to the Surface via a Decline

The three million tonnes of ore a year that is extracted from the Ernest Henry underground mine is trucked to the surface by means of a decline. This ore is reduced to 35,000 ounces of gold and 25,000 tonnes of copper in concentrate form. Work commenced on a 1,000 metre deep shaft at the mine in 2012 and when it is completed in 2013 production rates will double. This means future annual production will be in the vicinity of six million tonnes, producing 70,000 ounces of gold and 50,000 tonnes of copper in concentrate form.

Ernest Henry Mine On Site Processing

The ore removed from the mine is processed on site at the company's concentrator plant where the copper, gold and magnetite is separated. The copper concentrate, which still contains gold, is then transported by road transport to Glencore's copper smelter at Mount Isa where it is smelted into anode form. This is then taken by rail to the company's copper refinery at Townsville where it is refined into cathode. It is this copper cathode that is sent to Glencore customers both within Australia and those it is exported to in overseas countries from the port at Townsville. The magnetite concentrate is exported from Townsville is its concentrate state. Ore reserves at the Ernest Henry mine stood at 88 million tonnes in June 2010. These reserves contained 23 percent magnetite, 0.5 grams a tonne of gold and one percent copper.

Gold and Silver Exported as Tankhouse Slimes

During refining gold and silver is captured from the copper anode and sold off as 'tankhoue slimes.' It is exported in this state for further processing overseas. Magnetite is a highly magnetic mineral that is used primarily in steel making and in the washing of coal. The 95 percent magnetite concentrate produced at the Ernest Henry mine is a very high grade of iron ore. This concentrate is stockpiled at the mine site before being taken from the site in especially built haulage trucks to the rail load out and storage facility at Cloncurry. It is then transported by rail to Townsville for export.

Open pit Closed in 2011

The now closed open pit at the Ernest Henry mine was opened in 1997 and it continued a high level of production until it was closed in December 2011. Ore mined from the open pit was extracted in the conventional drilling, blasting shovelling and trucking method. The ore was blasted as the need arose and the resulting broken ore removed from the pit with 140 tonne dump trucks. Each truck was able to haul a 220 tonne load that was processed at the on site concentrator plant. The pit eventually grew to a size of one and a half kilometres long by 1.3 kilometres wide and 530 metres deep. Almost 700 million tonnes of ore was mined from the pit during its lifetime. It now serves as a portal for the underground operation.

Note- GlencoreXstrata was formed following a merger of Glencore International and Xstrata, the merger was completed in May 2013. But a decision was made by the Company's shareholders during the annual general meeting and the announcement was made in May 2014 that Glencore will drop Xstrata and be simply known as Glencore.