The Roșia Poieni copper mine is a large

open pit Open-pit mining, also known as open-cast or open-cut mining and in larger contexts mega-mining, is a surface mining technique that extracts rock or minerals from the earth. Open-pit mines are used when deposits of commercially useful ore or ...

copper Copper is a chemical element; it has symbol Cu (from Latin ) and atomic number 29. It is a soft, malleable, and ductile metal with very high thermal and electrical conductivity. A freshly exposed surface of pure copper has a pinkish-orang ...

mine in the centre of

Romania Romania is a country located at the crossroads of Central Europe, Central, Eastern Europe, Eastern and Southeast Europe. It borders Ukraine to the north and east, Hungary to the west, Serbia to the southwest, Bulgaria to the south, Moldova to ...

Transylvania Transylvania ( or ; ; or ; Transylvanian Saxon dialect, Transylvanian Saxon: ''Siweberjen'') is a List of historical regions of Central Europe, historical and cultural region in Central Europe, encompassing central Romania. To the east and ...

region, northwest of

Alba Iulia Alba Iulia (; or ''Carlsburg'', formerly ''Weißenburg''; ; ) is a city that serves as the seat of Alba County in the west-central part of Romania. Located on the river Mureș (river), Mureș in the historical region of Transylvania, it has a ...

and north of the capital

Bucharest Bucharest ( , ; ) is the capital and largest city of Romania. The metropolis stands on the River Dâmbovița (river), Dâmbovița in south-eastern Romania. Its population is officially estimated at 1.76 million residents within a greater Buc ...

. Geographically the mine is located in the

Apuseni Mountains The Apuseni Mountains (, "Western Mountains"; , "Transylvanian Mountains") are a mountain range in Transylvania, Romania, which belongs to the Western Romanian Carpathians. The highest peak is the Bihor Peak at . The Apuseni Mountains have ab ...

, south of the Arieș River in

Lupșa Lupșa (; ) is a commune located in Alba County, Transylvania, Romania. It is composed of 23 villages: Bârdești, Bârzan, Curmătură, După Deal, Geamăna, Hădărău, Holobani, Lazuri, Lunca, Lupșa, Mănăstire, Mărgaia, Mușca, Pârâu ...

commune. The Roșia Poieni deposit was developed between the 1950s and 1970s within the

Abrud Abrud (;Ștefan Pascu: A History of Transylvania, Dorset Press, 1990, , ; ) is a town in the north-western part of Alba County, Transylvania, Romania, located on the river Abrud. It administers three villages: Abrud-Sat (''Abrudfalva''), Gura C ...

–Mușca–Bucium area (the Golden Quadrilateral) from the Metaliferi ('Ore') Mountains, part of the Apuseni Mountains. , the mine produced around 11,000 tonnes of

a year and the mineral deposit represented 65% of the total copper reserves in Romania. The mine is owned by CupruMin, a state-owned company. The basin has a runoff river, which flows down into the valley where the village of Geamăna once was and infamously flooded it sometime in the late 1970s with toxic sludge. The flooded village is located at .

Location and access

Access to the site is made through a south-west industrial

haul road A haul road (also ''haulage road'' or haul track) is a term for roads designed for heavy or bulk transfer of materials by haul trucks in the mining industry. It is also used for freight-only roads in other contexts, for example in South Boston leadi ...

from Cornii Valley that crosses the National Road no. 74

Alba-Iulia Alba Iulia (; or ''Carlsburg'', formerly ''Weißenburg''; ; ) is a city that serves as the seat of Alba County in the west-central part of Romania. Located on the river Mureș in the historical region of Transylvania, it has a population of ...

–

Zlatna Zlatna (; ; ) is a town in Alba County, central Transylvania, Romania. The town administers eighteen villages: Botești (''Golddorf''; ''Botesbánya''), Budeni (''Higendorf''), Dealu Roatei (''Rotberg''), Dobrot, Dumbrava, Feneș (''Wildendorf''; ...

–

when entering Abrud and through a north industrial haul road from Mușca Valley that crosses the

National Road The National Road (also known as the Cumberland Road) was the first major improved highway in the United States built by the federal government. Built between 1811 and 1837, the road connected the Potomac and Ohio Rivers and was a main tran ...

Câmpeni –

Turda Turda (; , ; ; ) is a Municipiu, city in Cluj County, Transylvania, Romania. It is located in the southeastern part of the county, from the county seat, Cluj-Napoca, to which it is connected by the European route E81, and from nearby Câmpia ...

in Mușca village,

commune.

Geology

, Roșia Poieni represented the largest copper reserve in Romania and the second largest in Europe, having estimated reserves of 1.5 billion tonnes of ore grading 0.36% copper. It is enclosed by eruptive sub-volcanic

Miocene The Miocene ( ) is the first epoch (geology), geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and mea ...

rocks (micro-

diorite Diorite ( ) is an intrusive rock, intrusive igneous rock formed by the slow cooling underground of magma (molten rock) that has a moderate content of silica and a relatively low content of alkali metals. It is Intermediate composition, inter ...

or Fundoaia

andesite Andesite () is a volcanic rock of intermediate composition. In a general sense, it is the intermediate type between silica-poor basalt and silica-rich rhyolite. It is fine-grained (aphanitic) to porphyritic in texture, and is composed predomina ...

s). The Fundoaia body has the shape of a vertical column of in height (+ → ) and in horizontal plane having the following dimensions: ÷/÷. The eruptive body comes in contact (through the tectonic

breccia Breccia ( , ; ) is a rock composed of large angular broken fragments of minerals or Rock (geology), rocks cementation (geology), cemented together by a fine-grained matrix (geology), matrix. The word has its origins in the Italian language ...

) with andesite necks ( Poieni, Curmătura, Melciu, Piatra Tichileu, and Jgheabului Hills) and with sedimentary

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 143.1 to 66 mya (unit), million years ago (Mya). It is the third and final period of the Mesozoic Era (geology), Era, as well as the longest. At around 77.1 million years, it is the ...

rocks. The

porphyry copper deposit Porphyry copper deposits are copper ore bodies that are formed from hydrothermal fluids that originate from a voluminous magma chamber several kilometers below the deposit itself. Predating or associated with those fluids are vertical dikes of ...

is made up mainly of fine disseminations, nests and veinlets (0.02÷3 cm) of

pyrite The mineral pyrite ( ), or iron pyrite, also known as fool's gold, is an iron sulfide with the chemical formula Fe S2 (iron (II) disulfide). Pyrite is the most abundant sulfide mineral. Pyrite's metallic luster and pale brass-yellow hue ...

chalcopyrite Chalcopyrite ( ) is a copper iron sulfide mineral and the most abundant copper ore mineral. It has the chemical formula CuFeS2 and crystallizes in the tetragonal system. It has a brassy to golden yellow color and a Mohs scale, hardness of 3.5 to 4 ...

, and

magnetite Magnetite is a mineral and one of the main iron ores, with the chemical formula . It is one of the iron oxide, oxides of iron, and is ferrimagnetism, ferrimagnetic; it is attracted to a magnet and can be magnetization, magnetized to become a ...

;

gold Gold is a chemical element; it has chemical symbol Au (from Latin ) and atomic number 79. In its pure form, it is a brightness, bright, slightly orange-yellow, dense, soft, malleable, and ductile metal. Chemically, gold is a transition metal ...

included in the chalcopyrite and pyrite, and secondary minerals:

bornite Bornite, also known as peacock ore, is a sulfide mineral with chemical composition that crystallizes in the orthorhombic system (pseudo-cubic). It is an important copper ore. Appearance Bornite has a brown to copper-red color on fresh surfa ...

covellite Covellite (also known as covelline) is a rare copper sulfide mineral with the formula CuS. This indigo blue mineral is commonly a secondary mineral in limited abundance and although it is not an important ore of copper itself, it is well known ...

chalcocite Chalcocite (), copper(I) sulfide (Cu2S), is an important copper ore mineral. It is opaque and dark gray to black, with a metallic luster. It has a hardness of 2.5–3 on the Mohs scale. It is a sulfide with a monoclinic crystal system. T ...

sphalerite Sphalerite is a sulfide mineral with the chemical formula . It is the most important ore of zinc. Sphalerite is found in a variety of deposit types, but it is primarily in Sedimentary exhalative deposits, sedimentary exhalative, Carbonate-hoste ...

galena Galena, also called lead glance, is the natural mineral form of lead(II) sulfide (PbS). It is the most important ore of lead and an important source of silver. Galena is one of the most abundant and widely distributed sulfide minerals. It crysta ...

molybdenite Molybdenite is a mineral of molybdenum disulfide, Mo S2. Similar in appearance and feel to graphite, molybdenite has a lubricating effect that is a consequence of its layered structure. The atomic structure consists of a sheet of molybdenum at ...

germanite Germanite is a rare copper iron germanium sulfide mineral, Cu26Fe4Ge4S32. It was first discovered in 1922, and named for its germanium content. It is only a minor source of this important semiconductor element, which is mainly derived from the p ...

malachite Malachite () is a copper Carbonate mineral, carbonate hydroxide mineral, with the chemical formula, formula Basic copper carbonate, Cu2CO3(OH)2. This opaque, green-banded mineral crystallizes in the monoclinic crystal system, and most often for ...

azurite Azurite or '' Azure spar'Krivovichev V. G.'' Mineralogical glossary. Scientific editor A. G. Bulakh. — St.Petersburg: St.Petersburg Univ. Publ. House. 2009. — 556 p. — ISBN 978-5-288-04863-0. ''(in Russian)'' is a soft, deep-blue copp ...

and is developed in microdioritic rocks.

Ore processing

The ore extracted from the

is crushed in a gyratory crusher after being transported and stored in the crushed ore storage facility located within the processing plant site. , the processing plant had a design capacity of 9 million tonnes extracted and processed per year, the process being made on 4 technological lines of 7,500 tonnes per day. The plant was launched between 1985 and 1987. The ore is subsequently processed through a classical processing flow, with a two-stage

grind A blade's grind is its cross-sectional shape in a plane normal to the edge. Grind differs from Blade#Knife blade profiles .28Patterns.29, blade profile, which is the blade's cross-sectional shape in the plane containing the blade's edge and ...

ing phase in two autogenous mills and in two

ball mill A ball mill is a type of grinder filled with grinding balls, used to grind or blend materials for use in mineral dressing processes, paints, pyrotechnics, ceramics, and selective laser sintering. It works on the principle of impact and attri ...

s, followed by flotation, which is performed in pneumomechanical cells () where the primary concentrate is obtained, which subsequently is flotated in cells of where a

copper concentrate Copper extraction is the multi-stage process of obtaining copper from its ores. The conversion of copper ores consists of a series of physical, chemical, and electrochemical processes. Methods have evolved and vary with country depending on the ...

is obtained with a content between 16.5 and 20% copper. The concentrate is thickened in sided thickeners and filtered through a pressure filter (Larox).

References

External links

Official site

{{DEFAULTSORT:Rosia Poieni Copper Mine Copper mines in Romania Open-pit mines