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43-676: The Sunrise Dam Gold Mine is located 55 km south of Laverton, Western Australia , on the eastern margin of Lake Carey . It is fully owned by AngloGold Ashanti and comprises a large-scale mechanized underground mine with a conventional gravity and leach process plant. In 2015 the mine accounted for 5% of the company's production. The gold deposit was originally co-owned by the Granny Smith Joint Venture ( Placer Pacific Ltd and Delta Gold NL), which called its eastern portion "Sunrise", and by Acacia Resources Ltd, which called its western portion "Cleo". The Sunrise portion

86-596: A major cutback at the end of 2001, mining in the Mega Pit reached full capacity in the first half of 2002. A smaller cutback, in the Watu section of the pit, was approved during the year. In December 2002 AngloGold purchased the Sunrise lease from Placer Dome , obtaining control of the entire mineralised system at Sunrise Dam. During the first half of 2004 an underground scoping study was completed. Deep drilling indicated

129-466: A natural gas infrastructure company for the transportation of natural gas to Sunrise Dam and Tropicana Gold Mine . Production was 46,000oz lower in 2015 due to lower mined grades, with underground mining primarily on the periphery of the main ore bodies. The mine began transitioning to the Vogue ore body. A study commenced to assess the viability of an underground crusher and conveyor system for haulage via

172-802: A new decline at the northern end of the operation. Completion of the Eastern Goldfields Pipeline in December 2015 delivered natural gas ahead of schedule to Sunrise Dam and Tropicana Gold Mine . The switch to natural gas at Sunrise Dam involved the installation of two new gas generation sets. The pipeline was officially opened by the Western Australian Minister for Mines and Petroleum , the Honourable Bill Marmion , in February 2016. Mining

215-756: A nickel strike prompted the Poseidon bubble . The deposit was developed by Western Mining and its partners into the Windarra Nickel Project, which mined and processed nickel ore from 1974 to 1991. Laverton is primarily a mining area. There are two major operating gold mines in the district: the Wallaby Mine near Granny Smith , owned and operated by Gold Fields , and the Sunrise Dam Gold Mine , owned and operated by AngloGold Ashanti . Both open pit and underground mining

258-447: A single approach. Breast stoping is a method used in horizontal or near-horizontal ore bodies, where gravity is not usable to move the ore around. Breast stoping lacks the characteristic "steps" of either underhand or overhand stoping, being mined in a singular cut. Room and pillar is a type of breast stoping. Stull stoping is a form of stoping used in hardrock mining that uses systematic or random timbering ("stulls") placed between

301-449: Is a highly selective and productive method of mining and can cater for varying ore thicknesses and dips (0 – 90 degree). It differs from manual methods such as timbered and shrinkage as once the stope has begun blasting phase it cannot be accessed by personnel. For this reason the blasted rock is designed to fall into a supported drawpoint or removed with remote control LHD (load, haul, dump machine) . The biggest limitation with this method

344-601: Is a town in the Goldfields region of Western Australia , and the centre of administration for the Shire of Laverton . The town of Laverton is located at the western edge of the Great Victoria Desert , 957 kilometres (595 mi) north-northeast of the state capital, Perth , and 124 kilometres (77 mi) east-northeast of the town of Leonora , with an elevation of 461 metres (1,512 ft). About 20% of

387-564: Is carried out by contractors and ore is treated in a conventional gravity and leach process plant, which is owner-managed. The majority of the mine workers are on a fly-in fly-out roster, with National Jet Express providing a charter service twice-daily from Monday to Friday. Sunrise Dam supports the Laverton community through its involvement with the Laverton Mining Liaison Committee and representation on

430-614: Is conducted at these mines. The Murrin Murrin laterite nickel project is located 55 kilometres (34 mi) to the west, midway between Laverton and Leonora. The area has a long history of pastoralism with sheep, cattle and goats, and a substantial area of land is used in this way. According to census results from the Australian Bureau of Statistics , the population of the Laverton urban centre fell 23%, from 439 to 340 in

473-533: Is flat, tilted or vertical), the width of the deposit, the grade of the ore, the hardness and strength of the surrounding rock, and the cost of materials for supports. It is common to dig shafts vertically downwards to reach the ore body and then drive horizontal levels through it. Stoping then takes place from these levels. When the ore body is more or less horizontal, various forms of room and pillar stoping, cut and fill , or longwall mining can take place. In steeply-dipping ore bodies, such as lodes of tin ,

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516-561: Is structurally and lithologically controlled within gently dipping high strain shear zones (for example, the Sunrise Shear) and steeply dipping brittle-ductile low strain shear zones (for example, the Western Shear). Host rocks include andesitic volcanic rocks, volcanogenic sediments and magnetic shales. Past production figures were: Laverton, Western Australia Laverton , originally known as British Flag ,

559-434: Is the length of holes that can be accurately drilled by the production drill, larger diameter holes using in the hole hammer drills can be accurate to over 100 m in length while floating boom top hammer rigs are limited to ~30 m. Holes drilled underground are generally drilled perpendicular, in a radial pattern around the drive. For the blastholes to successfully extract the ore material they must be able to fire into

602-497: The 15 years from 2001 to 2016. Over this same period, the population of Indigenous Australians decreased from 37.6% (165 people) to 20.8% (71 people) of the town. Laverton has a semi-arid climate with hot summers and mild to cool winters. Stoping The earliest forms of stoping were conducted with hand tools or by fire-setting ; later gunpowder was introduced. From the 19th century onward, various other explosives, power-tools, and machines came into use. As mining progresses

645-685: The Laverton Leonora Cross Cultural Association. Sunrise Dam also supports and encourages the development of a number of local businesses, including Carey Mining, an indigenous-owned mining contractor. Sunrise Dam continues to maintain certification to OHSAS 18001 , ISO 14001 and the International Cyanide Management Code . A mine closure plan is in place, with waste dumps and paddock tailings dams progressively rehabilitated in line with this plan. Gold ore at Sunrise Dam

688-485: The Laverton area, including John Forrest , David Carnegie and Frank Hann . Gold was discovered in the British Flag area in 1896 and many prospectors and miners moved into the area. Among them was Dr Charles W. Laver, who became an enthusiastic supporter and promoter of the region. One of the most successful mines was Craiggiemore, and by 1897 a residential and business area known as British Flag had sprung up on

731-411: The antiquated method of squareset timbering. Shrinkage stoping is most suitable for steeply dipping ore bodies (70°—90°). In shrinkage stoping, mining proceeds from the bottom upwards, in horizontal slices (similar to cut and fill mining), with the broken ore being left in place for miners to work from. Because blasted rock takes up a greater volume than in situ rock (due to swell factor ), some of

774-418: The blasted ore (approximately 40%) must be removed to provide working space for the next ore slice. Once the top of the stope is reached all the ore is removed from the stope. The stope may be backfilled or left empty, depending on the rock conditions. Long hole stoping as the name suggests uses holes drilled by a production drill to a predetermined pattern as designed by a mining engineer. Long hole stoping

817-592: The expansion initially designed for 2.5Mtpa, however by year-end plant throughput had been further increased to 3Mtpa. As a result, gold production increased by 31% in 2001, to 295,000oz. A major cutback in the Cleo pit was completed during the year, whilst the corporate office was restructured and relocated from Melbourne to Perth . Following the capital expansions undertaken the previous year, gold production increased by 30% in 2002 to 382,000oz, as plant throughput rose by 41% to an annual rate of 3.4Mtpa. After completion of

860-469: The first quarter of 2009. 2007 saw production increase by 29% to a record 600,000 ounces. The GQ zone in the open pit provided the anticipated large volumes of high grade ore. Approximately 79,000 ounces of gold production was sourced from the underground mine. Progress was made in developing access to the Cosmo, Dolly and Watu lodes. A cutback of the north wall of the open pit began (North Wall Cutback), while

903-505: The foot and hanging wall of the vein. The method requires that the hanging wall and often the footwall be of competent rock as the stulls provide the only artificial support. This type of stope has been used up to a depth of 3,500 feet (1,077 m) and at intervals up to 12 feet (3.7 m) wide. The 1893 mining disaster at Dolcoath mine in Cornwall was caused by failure of the stulls holding up a huge weight of waste rock. Square-set timbering

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946-422: The invention of rock blasting and powered tools. In overhand stoping, the deposit is worked from the bottom upward, the reverse of underhand stoping. With the advent of rock blasting and power drills, it became the predominant direction of stoping. In combined stoping, the deposit is simultaneously worked from the bottom upward and the top downward, combining the techniques of overhand and underhand stoping into

989-542: The mine through a takeover of Acacia Resources Ltd, a move that also gained it a 33% stake in the Boddington project, which it sold in early 2009 for $ 1.5 billion. Acacia, originally formed and listed in 1994 when Shell Australia divested its gold and base metal activities, was delisted from the Australian Stock Exchange on 11 January 2000. An upgrade to the processing plant took place in 2001,

1032-406: The mineral deposit, such as sinking shafts and winzes , carving adits , tunnels, and levels, and establishing ventilation and transportation. A stope can be created in a variety of ways. The specific method of stoping depends on a number of considerations, both technical and economical, based largely on the geology of the ore body being mined. These include the incline of the deposit (whether it

1075-416: The pit early in 2004. As a result, mining moved into the higher-grade Watu section of the orebody, with production increasing by 15% to 410,000 ounces. First gold produced from the underground mine was in the fourth quarter of 2004. In 2005, open cut mining continued in the high-grade areas in the first half of the year, then onto the lower grade northern section of the pit from the third quarter. Open pit ore

1118-720: The population is of Aboriginal descent. The area is semi-arid, with a mean annual rainfall of 233 millimetres (9.2 in). It is also quite warm, with mean daily maximum temperatures ranging from 17 °C (62 °F) in July to 36 °C (97 °F) in January. Laverton is the westernmost town on the Outback Way  – a proposed highway which goes through the Northern Territory to Winton in outback Queensland. A number of early explorers travelled over

1161-541: The previous year, together with improved grades from the North Wall Cutback area of the pit. An insurance payout of A$ 30 million related to the 2011 pit wall failure was offset against cash costs. After more than 17 years of operation, the open pit was completed in 2013 to a depth of 490m below surface. Production increased to 276,000oz as higher grade ore from the Crown Pillar in the base of the open pit

1204-467: The stope has reached its engineered height, it may be left open or backfilled for support. A common historical method of hydraulic fill involved dumping waste rock into a completed stope, then slurrying in a mixture of mill sand and water. The water drains away leaving the sand to lock the fill in place. Other methods of hydraulic fill using cement and mill sand, such as paste fill, are more contemporary methods of stoping and unlikely used in conjunction with

1247-431: The stope is often backfilled with tailings , or when needed for strength, a mixture of tailings and cement. In old mines, stopes frequently collapse at a later time, leaving craters or flashes at the surface. They are an unexpected danger when records of underground mining have been lost with the passage of time. Stoping is considered "productive work", and is contrasted with "deadwork", the work required merely to access

1290-419: The stopes become long narrow near-vertical spaces, which, if one reaches the surface is known as a gunnis or goffen. A common method of mining such vertical ore bodies is stull stoping, see below. Open stoping is generally divided into two basic forms based on direction: overhand and underhand stoping, which refer to the removal of ore from above or below the level, respectively. It is also possible to combine

1333-520: The sub-vertical, high-grade zones, that had been a feature of open-cut mining at Sunrise Dam, continued at depth. Underground mining commenced later that year, initially as a three-year feasibility project incorporating two declines in the vicinity of defined underground reserves. The primary decline was named the Daniel Decline, after prominent local indigenous businessman Daniel Tucker. Abnormally heavy rainfall limited access to high-grade ore in

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1376-417: The two in a single operation. Underhand stoping, also known as horizontal-cut underhand or underbreaking stoping, is the working of an ore deposit from the top downwards. Like shrinkage stoping, underhand stoping is most suitable for steeply dipping ore bodies. Because of the mechanical advantage it offers hand tools being struck downward (rather than upward, against gravity), this method was dominant prior to

1419-623: The underground life of mine study was completed. Production decreased by 28% in 2008 to 433,000 ounces, as mining of the high-grade ore in the base of the Mega Pit was completed, with the pit reaching a depth of 440 metres. Mill feed comprised stockpiled ore and approximately 73,000 ounces of gold production was sourced from the underground mine. Open pit mining continued in the North Wall Cutback throughout 2009, whilst underground tonnage increased by 15%, yielding approximately 111,000oz. Overall production for 2009 decreased by 7%, to 401,000oz, equivalent to 9% of group gold production. A paste fill plant

1462-412: The west side of the mine. In March 1898 a townsite was approved as Laverton, in honour of Laver. In 1899, the residents sought to have a townsite surveyed, but by then the original Craiggiemore location had become unsuitable, so a new site was chosen about 3 kilometres (1.9 mi) north of the original lots. The new site was surveyed in July 1899 and the town of Laverton gazetted in July 1900. Laverton

1505-441: The work required to re-establish production. A study was undertaken during 2011 to test the potential for a bulk-cave operation to more efficiently extract underground ore over an extended life of mine. The study demonstrated that substantial tonnage could be mined via more productive and cost effective long hole open stoping methods. Production rose by 5% to 258,000oz in 2012, as Sunrise Dam recovered from flood-related disruptions

1548-613: Was 67,000 ounces. Record throughput of 3.9Mtpa was achieved in the process plant as a result of additional crushing and grinding circuit optimization. In 2006, AngloGold Ashanti signed a contract for conversion of its diesel power generators to liquefied natural gas (LNG) as a cost-saving measure as well as to protect the environment. The conversion was delayed by an explosion at the Varanus Island gas production installation and subsequent 2008 Western Australian gas crisis . The LNG-powered facility at Sunrise Dam began operation in

1591-608: Was constructed to enable larger stopes to be extracted. 396,000oz was produced in 2010, with the North Wall Cutback providing over 80% of production. Ore continued to be sourced from a combination of underground and open pit operations, with the use of lower-grade stockpiles to supplement the ore feed to the plant. The transition to underground ore continued during 2010. There were two significant events during 2011 that negatively impacted production, with production falling to 246,000oz. A major flood occurred in February, when 220mm of rain fell in two storms, less than five days apart. This

1634-620: Was found in August 1988, after a 500m by 500m BLEG survey. The Sunrise mine commenced operations in May 1995. The Cleo portion was first indicated by tenement-wide rotary air blast and aircore drilling in 1991. Acacia Resources commenced production in February 1997, with the first gold pour in March that year. The Sunrise Dam gold mine was officially opened by Premier of Western Australia Richard Court on 6 August 1997. In 1999, AngloGold acquired

1677-571: Was invented in the Comstock Lode , Virginia City, Nevada in the 1860s. Square-set stoping is a historical method of stoping which relies on interlocking timbers set into place forming a grid, wedged tightly against the rock. As the mining progresses, generally upwards, new timber sets are added to fill the void. Ore is dropped through the sets freely or fed into chutes and either loaded into ore cars or mucked out from there. Depending on rock conditions and other technical considerations, once

1720-486: Was processed. During the year studies were undertaken into the feasibility and advantages of piping natural gas for power generation, as an alternative to diesel. The underground mine transitioned to become the primary source of mill feed in 2014, delivering 2.43Mt of ore to the mill for the year. Stockpiled intermediate grade ore (average 1.45g/t) was blended with the underground ore to meet the processing plant capacity. In July 2014, AngloGold Ashanti signed agreements with

1763-408: Was supplemented in the processing plant by higher grade underground ore. Gold production increased by 11% to 455,000 ounces. Production increased slightly in 2006 to 465,000 ounces. Mining concentrated on the high-grade GQ lode in the open pit. Mining from the known underground reserves increased significantly, especially in the Sunrise and Western Shear zones. Gold production from the underground mine

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1806-415: Was the highest rainfall recorded in the 129 years of records for the Laverton district. In April, a wall failed in the south-eastern portion of the open pit, which prevented access to the open pit working areas. A new access ramp was constructed, which took approximately six months. The flood event impacted underground production for approximately four months. No injuries were sustained in either event, or in

1849-467: Was the terminus of a branch line of the Kalgoorlie to Leonora railway line , with the junction at Malcolm. By the late 1960s, Laverton was in decline, mainly because of the very low price of gold. In 1968 a Poseidon prospector Ken Shirley discovered nickel-bearing rocks at Windarra, 24 kilometres (15 mi) northwest of Laverton. In 1969 Poseidon began drilling Windarra. In September rumours of

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