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64-582: The mine was due to be shut down in 2019, but due to an increase in demand for pyrite from Yara in Siilinjärvi, mining was extended to continue approximately 14 more months. Pyrite is a byproduct of copper and zinc mining. As of now, mining is going to be continued until spring 2021. Above-ground refining will continue until 2025. Callio is a project to oversee the reuse of the Pyhäsalmi Mine once mining activities are halted permanently. The aim

128-475: A 900 000 euro budget per episode. The mine served as one location for filming, with sets both above and below ground, where a special film set was built 660 meters underground in abandoned storage tunnels. Filming in Pyhäsalmi took place between November 2018 and April 2019 with a film crew of 50 people. Most of the extras required were locals and even miners themselves. Other productions have also taken note of

192-435: A Fe face-centered cubic sublattice into which the S 2 ions are embedded. (Note though that the iron atoms in the faces are not equivalent by translation alone to the iron atoms at the corners.) The pyrite structure is also seen in other MX 2 compounds of transition metals M and chalcogens X = O , S , Se and Te . Certain dipnictides with X standing for P , As and Sb etc. are also known to adopt

256-448: A demo model of a pumped hydroelectric energy storage facility in the Pyhäsalmi Mine. The purpose of this co-operation is to design and develop on a smaller scale a pilot facility which can later be implemented in a full-scale version. Work is already underway, including the technical plans, timetables, and financing of the project. This is the first phase of Callio's plans for a pumped hydroelectric storage facility in Pyhäsalmi Mine. Once

320-602: A foul odor and corrosion of copper wiring. In the United States, in Canada, and more recently in Ireland, where it was used as underfloor infill, pyrite contamination has caused major structural damage. Concrete exposed to sulfate ions, or sulfuric acid, degrades by sulfate attack : the formation of expansive mineral phases, such as ettringite (small needle crystals exerting a huge crystallization pressure inside

384-403: A local farmer discovered gossan ore during a well construction. Shortly after a sample was delivered to Outokumpu Corporation for analysis and a more thorough geological survey was commenced, revealing a rich volcanogenic massive sulfide ore deposit (VMS-deposit) rich in zinc and copper . In 1959 a decision was made to open a new mine in the area and after few years of construction the mine

448-480: A resemblance to the conditions of pressurized lava tunnels in Mars and as such provide a good environment to test out such innovations. The project will also compare the differences in production above ground and underground. In July 2019 the first insect farm was built 1430 meters underground. It was announced on December 4, 2019 that Pumped Hydro Storage Sweden AB and Callio have signed a co-operation agreement to build

512-534: A sample of pyrite was placed against a circular file to strike the sparks needed to fire the gun. Pyrite is used with flintstone and a form of tinder made of stringybark by the Kaurna people of South Australia , as a traditional method of starting fires. Pyrite has been used since classical times to manufacture copperas ( ferrous sulfate ). Iron pyrite was heaped up and allowed to weather (an example of an early form of heap leaching ). The acidic runoff from

576-584: A simple liquid-phase exfoliation route. This is the first study to demonstrate the production of non-layered 2D-platelets from 3D bulk FeS 2 . Furthermore, they have used these 2D-platelets with 20% single walled carbon-nanotube as an anode material in lithium-ion batteries, reaching a capacity of 1000 mAh/g close to the theoretical capacity of FeS 2 . In 2021, a natural pyrite stone has been crushed and pre-treated followed by liquid-phase exfoliation into two-dimensional nanosheets, which has shown capacities of 1200 mAh/g as an anode in lithium-ion batteries. From

640-567: A thorough training program for professionals in the mining industry. At the same time experience is gained from whether a mine heading toward closure could be transformed into a state of the art training center. The approach of the program is holistic, providing attendees with training spanning the whole life cycle of a mine. The Pyhäsalmi Mine is especially well equipped for this, because it encompasses all aspects of mining from excavation to mill processing. The program provides lectures as well as hands on learning opportunities and can be tailored to suit

704-553: A total of 16 grand prix competition a year. The event was open to the public and televised as 12 strongmen from several countries participated in six events held on the mine mill grounds, as well as underground on the main level and in the open rock pit. Pyhäsalmi Mine is serving as the location for the MINETRAIN project created by Callio. The MINETRAIN project is coordinated by the Oulu Mining School and aims to create

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768-465: Is cubic and was among the first crystal structures solved by X-ray diffraction . It belongs to the crystallographic space group Pa 3 and is denoted by the Strukturbericht notation C2. Under thermodynamic standard conditions the lattice constant a {\displaystyle a} of stoichiometric iron pyrite FeS 2 amounts to 541.87 pm . The unit cell is composed of

832-551: Is a Finnish-Swedish science fiction drama television series. It was co-created by Aleksi Salmenperä, Mikko Pöllä and Roope Lehtinen. The first season premiered on SVT1 in Sweden on September 20, 2020, and on YLE TV1 in Finland on November 15, 2020. It was directed by Aleksi Salmenperä (episodes 1–4) and Anna Zackrisson (episodes 5–8). Although the story is set to occur in a fictional mining city in northern Sweden, site of

896-404: Is a common accessory mineral in igneous rocks, where it also occasionally occurs as larger masses arising from an immiscible sulfide phase in the original magma. It is found in metamorphic rocks as a product of contact metamorphism . It also forms as a high-temperature hydrothermal mineral , though it occasionally forms at lower temperatures. Pyrite occurs both as a primary mineral, present in

960-465: Is about 1 atm . A newer commercial use for pyrite is as the cathode material in Energizer brand non-rechargeable lithium metal batteries . Pyrite is a semiconductor material with a band gap of 0.95 eV . Pure pyrite is naturally n-type, in both crystal and thin-film forms, potentially due to sulfur vacancies in the pyrite crystal structure acting as n-dopants. During the early years of

1024-458: Is accelerated by the action of Acidithiobacillus bacteria which oxidize pyrite to first produce ferrous ions ( Fe ), sulfate ions ( SO 4 ), and release protons (   H , or H 3 O ). In a second step, the ferrous ions ( Fe ) are oxidized by O 2 into ferric ions ( Fe ) which hydrolyze also releasing   H ions and producing FeO(OH). These oxidation reactions occur more rapidly when pyrite

1088-423: Is accounted for by point symmetry groups C 3 i and C 3 , respectively. The missing center of inversion at S lattice sites has important consequences for the crystallographic and physical properties of iron pyrite. These consequences derive from the crystal electric field active at the sulfur lattice site, which causes a polarization of S ions in the pyrite lattice. The polarisation can be calculated on

1152-554: Is also the fastest growing in terms of the unroasted iron pyrites imports, with a CAGR of +27.8% from 2007 to 2016. In July 2020 scientists reported that they have observed a voltage-induced transformation of normally diamagnetic pyrite into a ferromagnetic material, which may lead to applications in devices such as solar cells or magnetic data storage. Researchers at Trinity College Dublin , Ireland have demonstrated that FeS 2 can be exfoliated into few-layers just like other two-dimensional layered materials such as graphene by

1216-428: Is an iron sulfide with the chemical formula Fe S 2 (iron (II) disulfide). Pyrite is the most abundant sulfide mineral . Pyrite's metallic luster and pale brass-yellow hue give it a superficial resemblance to gold , hence the well-known nickname of fool's gold . The color has also led to the nicknames brass , brazzle , and brazil , primarily used to refer to pyrite found in coal . The name pyrite

1280-432: Is an umbrella organization for a variety of non-mining activities in and around the mine. Of these, Callio Lab oversees scientific research and development. Proposed new activities include a secure underground data center , pumped hydroelectrical energy storage , plant and fungus growing laboratories, breeding sites for insects and fish, and several other types of underground businesses. One major project Callio pioneered

1344-526: Is brighter yellow with a greenish hue when wet and is softer (3.5–4 on Mohs' scale). Arsenopyrite (FeAsS) is silver white and does not become more yellow when wet. Iron pyrite is unstable when exposed to the oxidizing conditions prevailing at the Earth's surface: iron pyrite in contact with atmospheric oxygen and water, or damp, ultimately decomposes into iron oxyhydroxides ( ferrihydrite , FeO(OH)) and sulfuric acid ( H 2 SO 4 ). This process

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1408-443: Is brittle, gold is malleable. Natural gold tends to be anhedral (irregularly shaped without well defined faces), whereas pyrite comes as either cubes or multifaceted crystals with well developed and sharp faces easy to recognise. Well crystallised pyrite crystals are euhedral ( i.e. , with nice faces). Pyrite can often be distinguished by the striations which, in many cases, can be seen on its surface. Chalcopyrite ( CuFeS 2 )

1472-548: Is derived from the Greek πυρίτης λίθος ( pyritēs lithos ), 'stone or mineral which strikes fire', in turn from πῦρ ( pŷr ), 'fire'. In ancient Roman times, this name was applied to several types of stone that would create sparks when struck against steel ; Pliny the Elder described one of them as being brassy, almost certainly a reference to what is now called pyrite. By Georgius Agricola 's time, c.  1550 ,

1536-449: Is finely dispersed (framboidal crystals initially formed by sulfate reducing bacteria (SRB) in argillaceous sediments or dust from mining operations). Pyrite oxidation by atmospheric O 2 in the presence of moisture ( H 2 O ) initially produces ferrous ions ( Fe ) and sulfuric acid which dissociates into sulfate ions and protons , leading to acid mine drainage (AMD). An example of acid rock drainage caused by pyrite

1600-458: Is not a formally recognised mineral, and is named after the Peruvian scientist Jose J. Bravo (1874–1928). Pyrite is distinguishable from native gold by its hardness, brittleness and crystal form. Pyrite fractures are very uneven , sometimes conchoidal because it does not cleave along a preferential plane. Native gold nuggets , or glitters, do not break but deform in a ductile way. Pyrite

1664-464: Is operated around the clock in three shifts. Pyhäsalmi Mine has hosted numerous events due to its attraction as a unique location. It has hosted the deepest concert in the world (by Agonizer at 1271 m) as well as dance performances. The 11 km long spiral-shaped main tunnel has also seen several uphill running and cycling competitions. Activity has increased in recent years as Callio Pyhäjärvi has worked to create publicity and new opportunities for

1728-662: Is piloting underground insect production and is a two-year project beginning in December 2018. It is a joint collaboration between the following entities: city of Pyhäjärvi , Pyhäsalmi Mine Oy, Entocube Oy, Probot Oy, M-Solutions Oy, Muon Solutions Oy and Callio Pyhäjärvi . The aim is to build an ecological and efficient product plant. Principle characteristics of this type of production are remote control and -supervision and circular economy. Applications of technologies encompassing these characteristics can be found in subterranean living and space habitats. The tunnels of Pyhäsalmi Mine bear

1792-430: Is sprayed onto the exposed coal surfaces to reduce the hazard of dust explosions . This has the secondary benefit of neutralizing the acid released by pyrite oxidation and therefore slowing the oxidation cycle described above, thus reducing the likelihood of spontaneous combustion. In the long term, however, oxidation continues, and the hydrated sulfates formed may exert crystallization pressure that can expand cracks in

1856-419: Is the 2015 Gold King Mine waste water spill . Pyrite oxidation is sufficiently exothermic that underground coal mines in high-sulfur coal seams have occasionally had serious problems with spontaneous combustion . The solution is the use of buffer blasting and the use of various sealing or cladding agents to hermetically seal the mined-out areas to exclude oxygen. In modern coal mines, limestone dust

1920-424: Is the scientifically oriented Callio Lab . Callio Lab is a multidisciplinary R&D environment aiming to utilize better the unique infrastructure and facilities of the Pyhäsalmi Mine. The underground environment has numerous possibilities for research and experimentation in fields of physics, geosciences, underground construction, microbiology, food production, and life sciences. Callio Lab aims to bring new users to

1984-487: Is to make the mine into a hospitable operating environment for businesses and an underground research facility. It is a joint project by the town of Pyhäjärvi and the University of Oulu . The mine was opened in 1962 by Outokumpu , sold to Inmet mining in 2002, and obtained by First Quantum Minerals in 2013. Mining activities are projected to end in 2019, but above-ground operations will continue until 2025. In 1958

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2048-571: Is used to make marcasite jewelry . Marcasite jewelry, using small faceted pieces of pyrite, often set in silver , has been made since ancient times and was popular in the Victorian era . At the time when the term became common in jewelry making, "marcasite" referred to all iron sulfides including pyrite, and not to the orthorhombic FeS 2 mineral marcasite which is lighter in color, brittle and chemically unstable, and thus not suitable for jewelry making. Marcasite jewelry does not actually contain

2112-608: The Baltic region . Callio Lab's largest underground laboratory, Lab 2, was previously the prime candidate for the LAGUNA project, which fell through due to funding issues. LAGUNA is a proposed very large volume underground neutrino observatory , designed to study e.g., the excess of matter over antimatter in the universe. Pyhäsalmi mine would have been at the optimal distance from the CERN particle accelerators, which would have provided

2176-432: The 20th century, pyrite was used as a mineral detector in radio receivers, and is still used by crystal radio hobbyists. Until the vacuum tube matured, the crystal detector was the most sensitive and dependable detector available—with considerable variation between mineral types and even individual samples within a particular type of mineral. Pyrite detectors occupied a midway point between galena detectors and

2240-527: The Iberian Peninsula. In the beliefs of the Thai people (especially those in the south), pyrite is known as Khao tok Phra Ruang , Khao khon bat Phra Ruang (ข้าวตอกพระร่วง, ข้าวก้นบาตรพระร่วง) or Phet na tang , Hin na tang (เพชรหน้าทั่ง, หินหน้าทั่ง). It is believed to be a sacred item that has the power to prevent evil, black magic or demons. White Wall (TV drama) White Wall

2304-538: The Pyhäsalmi mine for destruction at the Forcit ammunition factory in Vihtavuori , where (after a year in storage) the container started to heat up and smoke. The reason for this potentially dangerous situation was revealed to be careless handling and packaging at the mine. This prompted significant changes in the safety protocols, and since 2013 all hazardous waste is destroyed on-site in Pyhäsalmi. The "main level" of

2368-452: The arrangement of the metal and diatomic anions differ from that of pyrite. Despite its name, chalcopyrite ( CuFeS 2 ) does not contain dianion pairs, but single S sulfide anions. Pyrite usually forms cuboid crystals, sometimes forming in close association to form raspberry-shaped masses called framboids . However, under certain circumstances, it can form anastomosing filaments or T-shaped crystals. Pyrite can also form shapes almost

2432-426: The basis of higher-order Madelung constants and has to be included in the calculation of the lattice energy by using a generalised Born–Haber cycle . This reflects the fact that the covalent bond in the sulfur pair is inadequately accounted for by a strictly ionic treatment. Arsenopyrite has a related structure with heteroatomic As–S pairs rather than S-S pairs. Marcasite also possesses homoatomic anion pairs, but

2496-515: The challenge was the environmental conditions, as the run was constant uphill, the temperature over 23 °C and humidity varying between levels of 50%-100%. Runners all had to wear safety helmets fashioned with headlights. Strongman Championships League Callio World Record Breakers competition was organized by Callio at Pyhäsalmi Mine on 7.9.2019. The competition was a part of the Strongman Champions League- circuit which has

2560-438: The concrete pores) and gypsum creates inner tensile forces in the concrete matrix which destroy the hardened cement paste, form cracks and fissures in concrete, and can lead to the ultimate ruin of the structure. Normalized tests for construction aggregate certify such materials as free of pyrite or marcasite. Pyrite is the most common of sulfide minerals and is widespread in igneous, metamorphic, and sedimentary rocks. It

2624-492: The creation, testing and optimizing it this demo facility for use is completed, Callio will move to phase two. Phase two aims to negotiate the fulfillment of a full-scale 75MW facility. In late 2022, the European Union approved €26.3 million for the 530 MWh project, equivalent for 7 hours. Pyrite The mineral pyrite ( / ˈ p aɪ r aɪ t / PY -ryte ), or iron pyrite , also known as fool's gold ,

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2688-481: The elevator (average speed 8 m/s, maximum 12 m/s (39 ft/s, 43 km/h, or 27 mp/h)). The same descent takes about 30 minutes by car or lorry, along the 11 km long decline access tunnel. Normal working hours in the mine are from 5 am to 10 pm. Blasting is done after 10 pm when the mine is empty due to safety protocols. Above ground facilities include the mill, hoisting towers, open blasting pit, waste pools, as well as workshops and warehouses. The mill

2752-419: The gold is "invisible gold" incorporated into the pyrite (see Carlin-type gold deposit ). It has been suggested that the presence of both gold and arsenic is a case of coupled substitution but as of 1997 the chemical state of the gold remained controversial. Pyrite gained a brief popularity in the 16th and 17th centuries as a source of ignition in early firearms , most notably the wheellock , where

2816-585: The heap was then boiled with iron to produce iron sulfate. In the 15th century, new methods of such leaching began to replace the burning of sulfur as a source of sulfuric acid . By the 19th century, it had become the dominant method. Pyrite remains in commercial use for the production of sulfur dioxide , for use in such applications as the paper industry , and in the manufacture of sulfuric acid. Thermal decomposition of pyrite into FeS ( iron(II) sulfide ) and elemental sulfur starts at 540 °C (1,004 °F); at around 700 °C (1,292 °F), p S 2

2880-404: The last decades, and the underground mine has become a test bed for new (often award-winning) access control, monitoring and automation technology. Underground accidents in Pyhäsalmi are very rare, and the last fatality occurred in 1995. Several easily contained on-ground refinery fires have however occurred at the site during the 2000s. In 2012, explosives contaminated with pyrite ore were sent from

2944-523: The mine and facilitate the beginning of new projects. Open call is continuous and new experiments or research plans can be proposed on their website. Callio Lab's workers assist new operators in getting started, this includes providing information, safety training and transportation in the mine as well as working as a liaison between them and the mine personnel. Callio Lab is a member of the BSUIN network, which consists of underground laboratories and facilities in

3008-432: The mine in multiple fields, such as film production, public events, as well as training and education. Pyhäsalmi Mine can be recognized as a filming location for the new sci-fi television series White Wall , with a cast led by Aksel Hennie , Vera Vitali and Eero Milonoff when it premieres in 2020. It is a Finnish-Swedish collaboration between Yle and SVT and is the most expensive Finnish television series made, with

3072-407: The mine is at 1400 meters depth and can be accessed with either the mine hoist or via the access tunnel. The main level houses a cafeteria, washrooms, showers, workshops, storage facilities, as well as a safety area. It is also home to the world's deepest sauna , at 1,410 metres (4,626 ft) underground. ( Guinness World Records ). Accessing the main level from the surface takes just 3 minutes using

3136-420: The mineral marcasite. The specimens of pyrite, when it appears as good quality crystals, are used in decoration. They are also very popular in mineral collecting. Among the sites that provide the best specimens are Soria and La Rioja provinces (Spain). In value terms, China ($ 47 million) constitutes the largest market for imported unroasted iron pyrites worldwide, making up 65% of global imports. China

3200-450: The more mechanically complicated perikon mineral pairs. Pyrite detectors can be as sensitive as a modern 1N34A germanium diode detector. Pyrite has been proposed as an abundant, non-toxic, inexpensive material in low-cost photovoltaic solar panels. Synthetic iron sulfide was used with copper sulfide to create the photovoltaic material. More recent efforts are working toward thin-film solar cells made entirely of pyrite. Pyrite

3264-733: The neutrino beams for the experiment. Plant Production in Mine was a project and study conducted by the Natural Resources Institute of Finland (LUKE) in Callio Lab laboratories at 660 meters underground. The goal of the project was to study how plant production can be implemented in a controlled underground environment. The experiment began with growing common hop ( Humulus lupulus ) in April 2018 using hydroponic technology. Fertilization, watering, air ventilation and temperature

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3328-715: The original sediments, and as a secondary mineral, deposited during diagenesis . Pyrite and marcasite commonly occur as replacement pseudomorphs after fossils in black shale and other sedimentary rocks formed under reducing environmental conditions. Pyrite is common as an accessory mineral in shale, where it is formed by precipitation from anoxic seawater, and coal beds often contain significant pyrite. Notable deposits are found as lenticular masses in Virginia, U.S., and in smaller quantities in many other locations. Large deposits are mined at Rio Tinto in Spain and elsewhere in

3392-444: The oxidation state of molybdenum is Mo . The mineral arsenopyrite has the formula Fe As S. Whereas pyrite has [S 2 ] units, arsenopyrite has [AsS] units, formally derived from deprotonation of arsenothiol (H 2 AsSH). Analysis of classical oxidation states would recommend the description of arsenopyrite as Fe [AsS] . Iron-pyrite FeS 2 represents the prototype compound of the crystallographic pyrite structure. The structure

3456-471: The participants previous experience. The first course was held in August 2019 with a class of 15 international professionals. The project leaders believe that through immersive training programs such as these, future mining operations can become more efficient and sustainable. They help the industry gain more knowledge and adopt a holistic point of view towards production and planning. The Pyhäsalmi mine will be

3520-528: The perspective of classical inorganic chemistry , which assigns formal oxidation states to each atom, pyrite and marcasite are probably best described as Fe [S 2 ] . This formalism recognizes that the sulfur atoms in pyrite occur in pairs with clear S–S bonds. These persulfide [ S–S ] units can be viewed as derived from hydrogen disulfide , H 2 S 2 . Thus pyrite would be more descriptively called iron persulfide, not iron disulfide. In contrast, molybdenite , Mo S 2 , features isolated sulfide S centers and

3584-685: The pyrite structure. The Fe atoms are bonded to six S atoms, giving a distorted octahedron. The material is a semiconductor . The Fe ions is usually considered to be low spin divalent state (as shown by Mössbauer spectroscopy as well as XPS). The material as a whole behaves as a Van Vleck paramagnet , despite its low-spin divalency. The sulfur centers occur in pairs, described as S 2 . Reduction of pyrite with potassium gives potassium dithioferrate , KFeS 2 . This material features ferric ions and isolated sulfide (S ) centers. The S atoms are tetrahedral, being bonded to three Fe centers and one other S atom. The site symmetry at Fe and S positions

3648-643: The rock and lead eventually to roof fall . Building stone containing pyrite tends to stain brown as pyrite oxidizes. This problem appears to be significantly worse if any marcasite is present. The presence of pyrite in the aggregate used to make concrete can lead to severe deterioration as pyrite oxidizes. In early 2009, problems with Chinese drywall imported into the United States after Hurricane Katrina were attributed to pyrite oxidation, followed by microbial sulfate reduction which released hydrogen sulfide gas ( H 2 S ). These problems included

3712-564: The same as a regular dodecahedron , known as pyritohedra, and this suggests an explanation for the artificial geometrical models found in Europe as early as the 5th century BC. Cattierite ( Co S 2 ), vaesite ( Ni S 2 ) and hauerite ( Mn S 2 ), as well as sperrylite ( Pt As 2 ) are similar in their structure and belong also to the pyrite group. Bravoite is a nickel-cobalt bearing variety of pyrite, with > 50% substitution of Ni for Fe within pyrite. Bravoite

3776-542: The site of Finland's first underground fire-, rescue- and safety training center. As of now, the closest training center of this type is in Norway. The project aims to utilize the soon to be closed mine and its already existing facilities and infrastructure. The main coordinator is Callio and the city of Pyhäjärvi with numerous professional partners and businesses, that specialize in fire extinction and safety systems, ICT solutions, and tunnel- and shaft rescue operations. Callio

3840-487: The term had become a generic term for all of the sulfide minerals . Pyrite is usually found associated with other sulfides or oxides in quartz veins , sedimentary rock , and metamorphic rock , as well as in coal beds and as a replacement mineral in fossils , but has also been identified in the sclerites of scaly-foot gastropods . Despite being nicknamed "fool's gold", pyrite is sometimes found in association with small quantities of gold. A substantial proportion of

3904-515: The unique location and in October 2019 the film Hiidenkirnu Giants Kettle will film scenes at the mine. Callio Extreme Run was held 19.5.2018 with over 50 participants treading the whole 11 km from the main level at 1410 meters underground to the top via the main access tunnel. The mine tunnel network consists of hundreds of kilometers of tunnel, so for the safety of the participants all other intersections and pathways were cordoned off. Adding to

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3968-433: Was controlled through automation and remote control. If optimal growing conditions can be characterized, this would broach the possibility of year-round production of hops with hundreds of harvests instead of just one. This could have the potential of replacing foreign imported hops for national breweries. Other plants that have been grown in the labs are potato, woad, and common nettle. Callio Edible Insects from Mine project

4032-419: Was opened on March 1, 1962. Pyhäsalmi mine was worked as an open cast pit until 1967, when underground mining operations commenced. In 1975, open cast mining was stopped. During the years the underground mine has been made gradually deeper. The so-called Olli Shaft was completed in 1985, making the mine 730 metres (2,400 ft) deep. New ore was discovered yet deeper, and a depth of 1,050 metres (3,440 ft)

4096-433: Was reached in 1996. Later a new shaft, called Timo Shaft was built to exploit the ore deposit between 1,050 and 1,440 metres (3,445 and 4,724 ft). Timo Shaft's construction work completed in 2001. By 2003, 38.2 million tons of ore have been processed, containing 1.2% copper, 3.1% zinc, gold 0.46 grams per ton, and silver 14.6 grams per ton. 15.6 million tons of ore remained. The mine safety has improved significantly over

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