Youanmi Gold Mine
Encyclopedia
The Youanmi Gold Mine is a gold mine 82 km south-south-west of the town of Sandstone
. It is near the abandoned town of Youanmi
, in the Murchison Region of Western Australia
.
The mine, owned by APEX Minerals NL, has been placed in care and maintenance since 1997. Youanmi was part of a three mine production strategy, together with the Wiluna Gold Mine
and the Gidgee Gold Mine
, and was scheduled to commence ore production in 2009. APEX has since abandoned plans to mine at Youanmi in the near future, relying on its other two mines instead.
In 1994, Youanmi became the first mine to commercially use the BACOX process (previously owned by BacTech Mining Corp, which is now REBgold Corp). This patented process, which is a proprietary of REBgold and BacTech Environmental, is a process of bacterial oxidation
and bioleaching
technologies that liberate precious metal
s from difficult-to-treat sulphide
ores and concentrates, using naturally occurring bacteria
. Incidentally, the Wiluna mine uses a similar process, the BIOX process.
The name Youanmi derives from a spring in the area and was first recorded in 1887. It was given to a surveyor by an old Aboriginal accompanying him, but its meaning is unclear.
-based company Bewick Moreing.
The current mine has its origins in the 1980s, when an open pit operation
commenced. In 1995, the mine moved to underground mining, where between 50,000 and 60,000 ounces of gold were mined per year, at an average grade of 11.5 g/t. In November 1997, the mine was closed because low gold prices, below A$400 per ounce, made the Youanmi mine uneconomic. At the time of its closure, Youanmi had produced 670,000 ounces of gold throughout its lifetime.
On 27 June 2000, Aquilia Resources Limited was listed on the Australian Securities Exchange
, thereby becoming the owner of the mine, taking over from their parent companies, Quartz Mountain Mining Pty Ltd and Australian Mineral Investors Pty Ltd .
In October 2003, Aquilia sold the Youanmi mine, which id called its Enterprise/Penny West Project, to Goldcrest Resources for A$2.75 million.
APEX purchased Youanmi in May 2007 from Goldcrest Resources Ltd for A$10 million, half of this in cash. It was purchased almost simultaneously with the Gidgee Gold Mine from Legend Mining for A$11 million.
APEX's initial plan was, to refurbish and enlarge the Gidgee processing plant and use it as a central processing facility for ore from Younami and Gidgee, where it would mine the Wilson deposit. Production was to commence in 18 to 24 month. Parts of the Younami processing plant were to be relocated to Gidgee while the remainder would be used for the company's Aphrodite project. Younami was to initially contribute 170,000 tonnes of ore to the future gold production, sourced from the existing underground operations below 600 meters, which would have to be dewatered and refurbished first.
With the acquisition of the Wiluna Gold Mine
in June 2007, Wiluna replaced Gidgee as the location of the central processing facility. Gidgee, like Youanmi, were to serve as mining locations only, with ore from Youanmi to be transported to Wiluna, over 320 km north-east of Youanmie. APEX also increased their production target from 120,000 to 200,000 ounces per annum because of the larger Wiluna plant and the lack of need to move parts of the Youanmi plant to Wiluna.
APEX announced first successful drilling results from Youanmi in December 2007 and anticipated that mining at Youanmi would commence in 2009.
In January 2008, APEX begun to dewater the open pit at Youanmi in order to gain access to the submerged underground portal, the pit being filled with 1.8 million cubic meters of water. It anticipated that the pit would be dewatered by the end of 2008, underground dewatering would start in early 2009 and ore production in the third quarter of 2009.
The company revised this plan, however and decided to only proceed with the development of the Wiluna mine, deferring mining at Youanmi to 2010. It halted all exploration activities at Gidgee and Younami, too. Difficulties encountered in the underground mining and plant commissioning at Wiluna forced APEX to go through a number of capital raisings, the latest in September 2009, when the company raised A$108 million. Consequently, APEX share price fell from a height of A$1.40 in early 2008 to below 4 cent by the end of 2009.
Subsequently, APEX returned to its previously abandoned strategy of sourcing ore from Gidgee as well as Wiluna for its processing facility. It now plans to commence mining at Gidgee once more in March 2010, while production from Youanmi is not planned any more at this time. In late December 2009, APEX announced a further delay with the development of the Gidgee mine because of the need of an upgrade of the Gidgee - Wiluna
road. APEX anticipates that mining could be delayed another two or three month.
The company has no immediate plans with Youanmi at the time and has not stated whether it is still continuing to dewater the operation, making a reopening in the near future unlikely.
In April 2010, APEX announced that it was considering selling the mine as it didn't consider it a core asset anymore.
Sandstone, Western Australia
Sandstone is a small town located in the Mid West region of Western Australia. The town is located 157 kilometres east of Mount Magnet and 661 kilometres north of the state capital, Perth...
. It is near the abandoned town of Youanmi
Youanmi, Western Australia
Youanmi is the name of an abandoned town in the Murchison Region of Western Australia.The town was gazetted in 1910 but abandoned in 1942, after the local gold mine was closed.-History:...
, in the Murchison Region of Western Australia
Western Australia
Western Australia is a state of Australia, occupying the entire western third of the Australian continent. It is bounded by the Indian Ocean to the north and west, the Great Australian Bight and Indian Ocean to the south, the Northern Territory to the north-east and South Australia to the south-east...
.
The mine, owned by APEX Minerals NL, has been placed in care and maintenance since 1997. Youanmi was part of a three mine production strategy, together with the Wiluna Gold Mine
Wiluna Gold Mine
The Wiluna Gold Mine is an active gold mine in Western Australia near the town of Wiluna. The mine was active from 1984 till its closure in 2007; when it was put into care and maintenance; and again since late 2008....
and the Gidgee Gold Mine
Gidgee Gold Mine
The Gidgee Gold Mine is a gold mine in Western Australia, 82 km north of the town of Sandstone. The mine was, until recently, owned by APEX Minerals NL, but purchased by Panoramic Resources in February 2011. The mine is currently in care and maintenance....
, and was scheduled to commence ore production in 2009. APEX has since abandoned plans to mine at Youanmi in the near future, relying on its other two mines instead.
In 1994, Youanmi became the first mine to commercially use the BACOX process (previously owned by BacTech Mining Corp, which is now REBgold Corp). This patented process, which is a proprietary of REBgold and BacTech Environmental, is a process of bacterial oxidation
Bacterial oxidation
Bacterial oxidation is a biohydrometallurgical process developed for pre-cyanidation treatment of refractory gold ores or concentrates. The bacterial culture is a mixed culture of Thiobacillus ferrooxidans, Thiobacillus thiooxidans and Leptospirillum ferrooxidans...
and bioleaching
Bioleaching
Bioleaching is the extraction of specific metals from their ores through the use of living organisms. This is much cleaner than the traditional heap leaching using cyanide...
technologies that liberate precious metal
Precious metal
A precious metal is a rare, naturally occurring metallic chemical element of high economic value.Chemically, the precious metals are less reactive than most elements, have high lustre, are softer or more ductile, and have higher melting points than other metals...
s from difficult-to-treat sulphide
Sulfide
A sulfide is an anion of sulfur in its lowest oxidation state of 2-. Sulfide is also a slightly archaic term for thioethers, a common type of organosulfur compound that are well known for their bad odors.- Properties :...
ores and concentrates, using naturally occurring bacteria
Bacteria
Bacteria are a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria have a wide range of shapes, ranging from spheres to rods and spirals...
. Incidentally, the Wiluna mine uses a similar process, the BIOX process.
The name Youanmi derives from a spring in the area and was first recorded in 1887. It was given to a surveyor by an old Aboriginal accompanying him, but its meaning is unclear.
History
After a first gold discovery in 1896, gold mining at Youanmi was carried out around 1908 and carried on until 1942, when the Youanmi Gold Mine was shut for the first time. The town of Youanmi rose and fell with the mine, finding itself deserted after the closure of the mine. The mine was, in those days, owned by LondonLondon
London is the capital city of :England and the :United Kingdom, the largest metropolitan area in the United Kingdom, and the largest urban zone in the European Union by most measures. Located on the River Thames, London has been a major settlement for two millennia, its history going back to its...
-based company Bewick Moreing.
The current mine has its origins in the 1980s, when an open pit operation
Open-pit mining
Open-pit mining or opencast mining refers to a method of extracting rock or minerals from the earth by their removal from an open pit or borrow....
commenced. In 1995, the mine moved to underground mining, where between 50,000 and 60,000 ounces of gold were mined per year, at an average grade of 11.5 g/t. In November 1997, the mine was closed because low gold prices, below A$400 per ounce, made the Youanmi mine uneconomic. At the time of its closure, Youanmi had produced 670,000 ounces of gold throughout its lifetime.
On 27 June 2000, Aquilia Resources Limited was listed on the Australian Securities Exchange
Australian Securities Exchange
The Australian Securities Exchange was created by the merger of the Australian Stock Exchange and the Sydney Futures Exchange in July 2006. It is the primary stock exchange group in Australia....
, thereby becoming the owner of the mine, taking over from their parent companies, Quartz Mountain Mining Pty Ltd and Australian Mineral Investors Pty Ltd .
In October 2003, Aquilia sold the Youanmi mine, which id called its Enterprise/Penny West Project, to Goldcrest Resources for A$2.75 million.
APEX purchased Youanmi in May 2007 from Goldcrest Resources Ltd for A$10 million, half of this in cash. It was purchased almost simultaneously with the Gidgee Gold Mine from Legend Mining for A$11 million.
APEX's initial plan was, to refurbish and enlarge the Gidgee processing plant and use it as a central processing facility for ore from Younami and Gidgee, where it would mine the Wilson deposit. Production was to commence in 18 to 24 month. Parts of the Younami processing plant were to be relocated to Gidgee while the remainder would be used for the company's Aphrodite project. Younami was to initially contribute 170,000 tonnes of ore to the future gold production, sourced from the existing underground operations below 600 meters, which would have to be dewatered and refurbished first.
With the acquisition of the Wiluna Gold Mine
Wiluna Gold Mine
The Wiluna Gold Mine is an active gold mine in Western Australia near the town of Wiluna. The mine was active from 1984 till its closure in 2007; when it was put into care and maintenance; and again since late 2008....
in June 2007, Wiluna replaced Gidgee as the location of the central processing facility. Gidgee, like Youanmi, were to serve as mining locations only, with ore from Youanmi to be transported to Wiluna, over 320 km north-east of Youanmie. APEX also increased their production target from 120,000 to 200,000 ounces per annum because of the larger Wiluna plant and the lack of need to move parts of the Youanmi plant to Wiluna.
APEX announced first successful drilling results from Youanmi in December 2007 and anticipated that mining at Youanmi would commence in 2009.
In January 2008, APEX begun to dewater the open pit at Youanmi in order to gain access to the submerged underground portal, the pit being filled with 1.8 million cubic meters of water. It anticipated that the pit would be dewatered by the end of 2008, underground dewatering would start in early 2009 and ore production in the third quarter of 2009.
The company revised this plan, however and decided to only proceed with the development of the Wiluna mine, deferring mining at Youanmi to 2010. It halted all exploration activities at Gidgee and Younami, too. Difficulties encountered in the underground mining and plant commissioning at Wiluna forced APEX to go through a number of capital raisings, the latest in September 2009, when the company raised A$108 million. Consequently, APEX share price fell from a height of A$1.40 in early 2008 to below 4 cent by the end of 2009.
Subsequently, APEX returned to its previously abandoned strategy of sourcing ore from Gidgee as well as Wiluna for its processing facility. It now plans to commence mining at Gidgee once more in March 2010, while production from Youanmi is not planned any more at this time. In late December 2009, APEX announced a further delay with the development of the Gidgee mine because of the need of an upgrade of the Gidgee - Wiluna
Wiluna, Western Australia
Wiluna is a complex town in the Mid West region of Western Australia. It is situated on the edge of the Western Desert at the gateway to the Canning Stock Route and Gunbarrel Highway. It is the service centre of the local area for the local Aboriginal people, the pastoral industry, mining, and...
road. APEX anticipates that mining could be delayed another two or three month.
The company has no immediate plans with Youanmi at the time and has not stated whether it is still continuing to dewater the operation, making a reopening in the near future unlikely.
In April 2010, APEX announced that it was considering selling the mine as it didn't consider it a core asset anymore.
Ownership
Previous owners of the Youanmi Gold Mine:| Company | From | To |
| Aquila Resources Ltd | June 2000 | October 2003 |
| Goldcrest Resources Ltd | October 2003 | May 2007 |
| APEX Minerals NL | May 2007 | present |
Further reading
- Jean M. Hooper : Youanmi : A Story of Murchison Gold, Hesperian Press, published: 1987, ISBN 0-85905-104-8
Sources
- The Australian Mines Handbook: 2003-2004 Edition, Louthean Media Pty Ltd, Editor: Ross Louthean
- Western Australian Mineral and Petroleum Statistics Digest 2008 Page 34: Principal Mineral and Petroleum Producers - Gold