Kittilä mine
Encyclopedia
Kittilä mine, also known as Suurikuusikko mine, is a gold
mine
in Kittilä
, in the Lapland Province of Finland
. The mine
is owned and operated by Agnico-Eagle Mines Limited and is located 55 kilometres (34.2 mi) north of Kittilä
. Exploration began in 1986, and production started in 2008. The mine is composed of two open pits
, with the proceeds of the operation funding an underground mining operation, accessed by a ramp from surface and utilizing both transverse and longitudinal long-hole stoping methods
. The mine utilizes on-site concentrating
to produce Doré bar
s for shipment off-site for refinement, and is scheduled to produce 150000 ounces (4,252,428.5 g) of gold in 2009.
of Finland initiated exploration which resulted in a discovery of gold mineralization
. Diamond drilling
continued up to 1991, when exploration ended. In 1998 the property was sold to Svenska Platina AB, a junior mining company which was a subsidiary of Riddarhyttan Resources AB. Permitting for an open pit mine
began in 2002, with a mining licence and permit secured in 2003. Agnico Eagle purchased a stake in Riddarhyttan (at the time feasibility studies suggested the resource was between 2—3.7 million ounces of gold) in 2004, with the remainder of the company being purchased in 2005. Diamond drilling continued in 2005, with an additional 460 holes drilled over 136000 metres (446,194.2 ft). In September 2008 an additional 60 kilometres (196,850.4 ft) of drilling resulted in a gold reserve increase of two million ounces (5.7 million ounces total), over 18.2 million tonnes of ore, grading 5.12 grams per tonne. Excavation of the open pit began in September 2007 and ore production began in May 2008. Mining in the Suuri pit began at 2500 tonnes (2,755.8 ST) per day to be increased to 3000 tonnes (3,306.9 ST) by the end of 2009.
The ore zone at the Kittilä mine (mined by what are known as the Suuri and Roura pits) is approximately 4.5 km (2.8 mi) long, 3.3 km (2.1 mi) wide, 1.1 km (0.683510010314787 mi) deep. Drilling is done using both Sandvik
and Atlas Copco
drill rigs, with ore
being loaded into Caterpillar 777 dump truck
s (pictured) by Caterpillar
385 hydraulic excavators. Mining in the pits is expected to last for up to five years. Proceeds from the pits are being used to finance the underground mining operation. The pit produces 65000 tonnes (71,650.2 ST) of material per month, removing eight tons of waste
per ton of ore. Provided they are able to acquire larger trucks, Agnico will increase their monthly tonnage to 100000 tonnes (110,231.1 ST).
, either along strike
(longitudinal) in the case of narrow areas (less than 5 metres (16.4 ft)), and perpendicular (transverse) to the ore body in the case of wider zones. Levels are designed to be 30 metres (98.4 ft) apart (from the floor to floor).
at the Kittila mine begins with a crusher
and semi-autogenous grinding mill
(SAG Mill), where ore is sized to 5.5 mm (0.216535433070866 in). The ore is then sent to flotation cells
where the gold (located in sulphide
material) is separated from gangue
material. The concentrated ore is sent to an autoclave
, and heated to 190|C at a pressure of 19 bars (1,900 kPa). This heat and the addition of oxygen separates the gold from the sulphide material. The separated material is then leached
out using carbon. The carbon is removed from the leached material and the gold is smelted
into 800 ounces (22.7 kg) Doré bar
s, which are sent off-site for further refining. Kittila realizes an average gold recovery of 92%, and has the capacity to produce up to four bars per week.
The Kittila mill also includes a bomb shelter
, a legal requirement under a 1917 Finnish law which came into effect following Finnish independence from Russia. The shelter is open for viewing by visitors and contains emergency supplies such as oxygen tanks, food, drink and a set of golf clubs.
Gold
Gold is a chemical element with the symbol Au and an atomic number of 79. Gold is a dense, soft, shiny, malleable and ductile metal. Pure gold has a bright yellow color and luster traditionally considered attractive, which it maintains without oxidizing in air or water. Chemically, gold is a...
mine
Gold mining
Gold mining is the removal of gold from the ground. There are several techniques and processes by which gold may be extracted from the earth.-History:...
in Kittilä
Kittilä
Kittilä is a municipality of Finland and a popular holiday resort.It is located in the province of Lapland, Finland. The municipality has a population of and covers an area of of which is water. The population density is ....
, in the Lapland Province of Finland
Finland
Finland , officially the Republic of Finland, is a Nordic country situated in the Fennoscandian region of Northern Europe. It is bordered by Sweden in the west, Norway in the north and Russia in the east, while Estonia lies to its south across the Gulf of Finland.Around 5.4 million people reside...
. The mine
Mining
Mining is the extraction of valuable minerals or other geological materials from the earth, from an ore body, vein or seam. The term also includes the removal of soil. Materials recovered by mining include base metals, precious metals, iron, uranium, coal, diamonds, limestone, oil shale, rock...
is owned and operated by Agnico-Eagle Mines Limited and is located 55 kilometres (34.2 mi) north of Kittilä
Kittilä
Kittilä is a municipality of Finland and a popular holiday resort.It is located in the province of Lapland, Finland. The municipality has a population of and covers an area of of which is water. The population density is ....
. Exploration began in 1986, and production started in 2008. The mine is composed of two open pits
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....
, with the proceeds of the operation funding an underground mining operation, accessed by a ramp from surface and utilizing both transverse and longitudinal long-hole stoping methods
Stoping (mining method)
Stoping is the removal of the wanted ore from an underground mine leaving behind an open space known as a stope. Stoping is used when the country rock is sufficiently strong not to cave into the stope, although in most cases artificial support is also provided...
. The mine utilizes on-site concentrating
Mineral processing
In the field of extractive metallurgy, mineral processing, also known as mineral dressing or ore dressing, is the process of separating commercially valuable minerals from their ores.-History:...
to produce Doré bar
Dore bar
A doré bar is a semi-pure alloy of gold and silver, usually created at the site of a mine. It is then transported to a refinery for further purification.The proportions of silver and gold can vary widely...
s for shipment off-site for refinement, and is scheduled to produce 150000 ounces (4,252,428.5 g) of gold in 2009.
History
In 1986 gold was discovered near the town of Kittilä. The Geological SurveyGeological survey
The term geological survey can be used to describe both the conduct of a survey for geological purposes and an institution holding geological information....
of Finland initiated exploration which resulted in a discovery of gold mineralization
Mineralization (geology)
In geology, mineralization is the hydrothermal deposition of economically important metals in the formation of ore bodies or "lodes".The first scientific studies of this process took place in Cornwall, United Kingdom by J.W.Henwood FRS and later by R.W...
. Diamond drilling
Exploration diamond drilling
Exploration diamond drilling is used in the mining industry to probe the contents of known ore deposits and potential sites. By withdrawing a small diameter core of rock from the orebody, geologists can analyze the core by chemical assay and conduct petrologic, structural and mineralogic studies...
continued up to 1991, when exploration ended. In 1998 the property was sold to Svenska Platina AB, a junior mining company which was a subsidiary of Riddarhyttan Resources AB. Permitting for an open pit mine
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....
began in 2002, with a mining licence and permit secured in 2003. Agnico Eagle purchased a stake in Riddarhyttan (at the time feasibility studies suggested the resource was between 2—3.7 million ounces of gold) in 2004, with the remainder of the company being purchased in 2005. Diamond drilling continued in 2005, with an additional 460 holes drilled over 136000 metres (446,194.2 ft). In September 2008 an additional 60 kilometres (196,850.4 ft) of drilling resulted in a gold reserve increase of two million ounces (5.7 million ounces total), over 18.2 million tonnes of ore, grading 5.12 grams per tonne. Excavation of the open pit began in September 2007 and ore production began in May 2008. Mining in the Suuri pit began at 2500 tonnes (2,755.8 ST) per day to be increased to 3000 tonnes (3,306.9 ST) by the end of 2009.
Open pit
Sandvik
Sandvik is a Swedish company founded in 1862 by Göran Fredrik Göransson in Sandviken. It is a high-technology engineering group and a world-leader in tooling, stainless steel alloys and materials technology, mining and construction...
and Atlas Copco
Atlas Copco
Atlas Copco is a Swedish industrial company that was founded in 1873. It manufactures industrial tooling and equipment.The Atlas Copco Group is a global industrial group of companies headquartered in Stockholm, Sweden. Revenues for 2009 totaled 63 billion SEK. The Group employs more than 33,000...
drill rigs, with ore
Ore
An ore is a type of rock that contains minerals with important elements including metals. The ores are extracted through mining; these are then refined to extract the valuable element....
being loaded into Caterpillar 777 dump truck
Caterpillar 777 dump truck
The Caterpillar 777 dump truck is a model of large dump trucks, typically used in open pit mining, manufactured by Caterpillar Inc.The truck's capacity is 80 tonnes....
s (pictured) by Caterpillar
Caterpillar Inc.
Caterpillar Inc. , also known as "CAT", designs, manufactures, markets and sells machinery and engines and sells financial products and insurance to customers via a worldwide dealer network. Caterpillar is the world's largest manufacturer of construction and mining equipment, diesel and natural gas...
385 hydraulic excavators. Mining in the pits is expected to last for up to five years. Proceeds from the pits are being used to finance the underground mining operation. The pit produces 65000 tonnes (71,650.2 ST) of material per month, removing eight tons of waste
Stripping ratio
In mining, stripping ratio or strip ratio refers to the ratio of the volume of overburden required to be removed to the volume of ore recovered...
per ton of ore. Provided they are able to acquire larger trucks, Agnico will increase their monthly tonnage to 100000 tonnes (110,231.1 ST).
Underground
Underground development began in October 2006. Access tunnels are 8 metres (26.2 ft) wide, which will permit the use of haul trucks up to 60-tonne capacity. Underground mining will be done using long-hole stoping methodsStoping (mining method)
Stoping is the removal of the wanted ore from an underground mine leaving behind an open space known as a stope. Stoping is used when the country rock is sufficiently strong not to cave into the stope, although in most cases artificial support is also provided...
, either along strike
Strike and dip
Strike and dip refer to the orientation or attitude of a geologic feature. The strike line of a bed, fault, or other planar feature is a line representing the intersection of that feature with a horizontal plane. On a geologic map, this is represented with a short straight line segment oriented...
(longitudinal) in the case of narrow areas (less than 5 metres (16.4 ft)), and perpendicular (transverse) to the ore body in the case of wider zones. Levels are designed to be 30 metres (98.4 ft) apart (from the floor to floor).
Processing
The millMineral processing
In the field of extractive metallurgy, mineral processing, also known as mineral dressing or ore dressing, is the process of separating commercially valuable minerals from their ores.-History:...
at the Kittila mine begins with a crusher
Crusher
A crusher is a machine designed to reduce large rocks into smaller rocks, gravel, or rock dust. Crushers may be used to reduce the size, or change the form, of waste materials so they can be more easily disposed of or recycled, or to reduce the size of a solid mix of raw materials , so that pieces...
and semi-autogenous grinding mill
Mill (grinding)
A grinding mill is a unit operation designed to break a solid material into smaller pieces. There are many different types of grinding mills and many types of materials processed in them. Historically mills were powered by hand , working animal , wind or water...
(SAG Mill), where ore is sized to 5.5 mm (0.216535433070866 in). The ore is then sent to flotation cells
Froth flotation
Froth flotation is a process for selectively separating hydrophobic materials from hydrophilic. This is used in several processing industries...
where the gold (located in 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 :...
material) is separated from gangue
Gangue
In mining, gangue is the commercially worthless material that surrounds, or is closely mixed with, a wanted mineral in an ore deposit. The separation of mineral from gangue is known as mineral processing, mineral dressing or ore dressing and it is a necessary and often significant aspect of mining...
material. The concentrated ore is sent to an autoclave
Autoclave
An autoclave is an instrument used to sterilize equipment and supplies by subjecting them to high pressure saturated steam at 121 °C for around 15–20 minutes depending on the size of the load and the contents. It was invented by Charles Chamberland in 1879, although a precursor known as the...
, and heated to 190|C at a pressure of 19 bars (1,900 kPa). This heat and the addition of oxygen separates the gold from the sulphide material. The separated material is then leached
Leaching (metallurgy)
Leaching is a widely used extractive metallurgy technique which converts metals into soluble salts in aqueous media. Compared to pyrometallurgical operations, leaching is easier to perform and much less harmful, because no gaseous pollution occurs...
out using carbon. The carbon is removed from the leached material and the gold is smelted
Smelting
Smelting is a form of extractive metallurgy; its main use is to produce a metal from its ore. This includes iron extraction from iron ore, and copper extraction and other base metals from their ores...
into 800 ounces (22.7 kg) Doré bar
Dore bar
A doré bar is a semi-pure alloy of gold and silver, usually created at the site of a mine. It is then transported to a refinery for further purification.The proportions of silver and gold can vary widely...
s, which are sent off-site for further refining. Kittila realizes an average gold recovery of 92%, and has the capacity to produce up to four bars per week.
The Kittila mill also includes a bomb shelter
Air-raid shelter
Air-raid shelters, also known as bomb shelters, are structures for the protection of the civil population as well as military personnel against enemy attacks from the air...
, a legal requirement under a 1917 Finnish law which came into effect following Finnish independence from Russia. The shelter is open for viewing by visitors and contains emergency supplies such as oxygen tanks, food, drink and a set of golf clubs.