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43-486: The Tagebau Hambach is a large open-pit coal mine ( German : Tagebau ) in Niederzier and Elsdorf , North Rhine–Westphalia, Germany. It is operated by RWE and used for mining lignite . The mine is on the site of the ancient Hambach Forest , which was purchased by RWE in 1978. The company then cut most of the forest down and cleared it to mine. Only 10% of the forest area remains. RWE planned to clear half of

86-506: A capacity of ten gigawatts could be installed as a floating solar park, as has already been realised in other parts of the world. According to Erfurt, the construction of a state-of-the-art plant for cell and module production is currently being evaluated. In an interview with Radio Rur, Uwe Rau replied that such an idea was feasible, as a major advantage of the Hambach open-cast mine was the power transmission lines already in place due to

129-447: A mine that contribute to this load: drilling , blasting, loading, and hauling . Waste rock is hauled to a waste dump. Waste dumps can be piled at the surface of the active pit, or in previously mined pits. Leftover waste from processing the ore is called tailings , and is generally in the form of a slurry . This is pumped to a tailings dam or settling pond, where the water is reused or evaporated. Tailings dams can be toxic due to

172-429: A number of worked-out mines. After mining ends at a location, the mine area may undergo land rehabilitation . Waste dumps are contoured to flatten them out, to further stabilize them. If the ore contains sulfides it is usually covered with a layer of clay to prevent ingress of rain and oxygen from the air, which can oxidize the sulfides to produce sulfuric acid , a phenomenon known as acid mine drainage . This

215-470: A pumped-storage plant in the Hambach open-cast mine can be realized and can provide many times the pumped-storage capacity currently available in Germany. The increased use of renewable energy makes this option more important and is being followed with interest by the mining authority. On 6 May 2020, Meyer Burger , a manufacturer of solar cell production machinery, presented its idea for a huge solar park in

258-477: A result of room and pillar mining . Untopping removes the overburden from above this, opens up the mine from above, and then allows the previously 'trapped' minerals to be won. Untopping was a feature of Welsh slate workings in the 1930s and 2000s, where Martyn Williams-Ellis, manager at Llechwedd found that earlier Victorian workings could be kept profitable with the newly mechanised techniques for bulk excavation to extract their pillars, and more recently across

301-456: A settlement with around two dozen tree houses and numerous road barricades. The barricades were erected to prevent mining company and police vehicles from entering. In November 2017, environmentalists entered the mine and temporarily halted operations. They were met with police using horses and pepper spray. In 2004, Greenpeace activists demonstrated against climate damage in the Hambach mine due to power generation using lignite. They flew over

344-559: A size of 85 km. It is the deepest open pit mine with respect to sea level : the bottom of the pit, with up to 500 metres (1,640 ft) from the surface, is 299 metres (981 ft) below sea level, the deepest artificially made point in North Rhine–Westphalia. The open pit operator RWE, then known as Rheinbraun , initiated the permitting process for open-pit mining in 1974 and was able to commence operations in 1978. The first excavator began its work on 15 October 1978. This

387-450: Is a crucial aspect of determining whether or not a geotechnical engineering design for open-pit slopes is attainable. Groundwater control systems, which include dewatering and depressurization wells, may also have a large impact on local groundwater. Because of this, an optimization-based version of the control system is required to ensure that local and regional hydro-geological impacts are within acceptable ranges. Open Pit depressurization

430-509: Is determined by the size of the equipment being used, generally 20–40 metres wide. Downward ramps are created to allow mining on a new level to begin. This new level will become progressively wider to form the new pit bottom. Most walls of the pit are generally mined on an angle less than vertical. Waste rock is stripped when the pit becomes deeper, therefore this angle is a safety precaution to prevent and minimize damage and danger from rock falls. However, this depends on how weathered and eroded

473-401: Is the process of removing tensions or pressure from different areas of a mine. Depressurization helps to make open-pit mines more stable and secure. By using an integrated mine slope depressurization program the likelihood that mine plans can be achieved, and at an acceptable level of risk increase drastically. Depressurization allows considerable expansions of a mine, and can extend the life of

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516-559: Is then generally covered with soil , and vegetation is planted to help consolidate the material. Eventually this layer will erode, but it is generally hoped that the rate of leaching or acid will be slowed by the cover such that the environment can handle the load of acid and associated heavy metals. There are no long term studies on the success of these covers due to the relatively short time in which large-scale open-pit mining has existed. It may take hundreds to thousands of years for some waste dumps to become "acid neutral" and stop leaching to

559-655: Is transported via the Hambach industrial spur  [ de ] to Bergheim – Auenheim, and from there via the North–South industrial spur  [ de ] to the power stations Niederaussem , Neurath , Frimmersdorf , and Goldenberg  [ de ] , near Hürth-Knapsack . The overburden was, until 16 April 2009, partially transported by conveyor belt to the Bergheim mine, which has run out of coal and therefore been refilled and recultivated. The visible mark of

602-668: The Lusatian Lake District , the Central German Lake District or the Upper Palatinate Lake District. A particular concern in the formation of these lakes is acid mine drainage . Open-pit mines create a significant amount of waste. Almost one million tons of ore and waste rock can move from the largest mines per day, and a couple thousand tons moved from small mines per day. There are generally four main operations in

645-594: The Philippines and Indonesia . In 2024, nickel mining and processing was one of the main causes of deforestation in Indonesia . Open-pit cobalt mining has led to deforestation and habitat destruction in the Democratic Republic of Congo . Open-pit mines operating in an area with heavy groundwater features may eventually face hydrology-related problems. This includes heaving and bursting of

688-418: The mineral resource is exhausted, or an increasing ratio of overburden to ore makes further mining uneconomic. After open-pit mines are closed, they are sometimes converted to landfills for disposal of solid waste. Some form of water control is usually required to keep the mine pit from becoming a lake. Several former open-pit mines have been deliberately converted into artificial lakes, forming areas such as

731-606: The Hambach open-cast mine. This would generate electricity with a capacity of around ten gigawatts, which would roughly correspond to the capacity of the Weisweiler, Neurath, Niederaussem, and Frimmersdorf coal-fired power plants, which are currently dependent on the open-cast mines. Considerations for later use of the area of fifty square kilometres include flooding to form a lake landscape. According to Meyer Burger CEO, Gunter Erfurt, it would be conceivable to cover Lake Hambach with solar modules. Up to fifty million solar modules with

774-402: The areas surrounding open-pit mines. Open-pit gold mining is one of the highest potential mining threats on the environment as it affects the air and water chemistry. The exposed dust may be toxic or radioactive, making it a health concern for the workers and the surrounding communities. Open-pit nickel mining has led to environmental degradation and pollution in developing countries such as

817-645: The complainants, it is difficult to prove the mining operator guilty. The newly formed brown coal committee therefore decided on 16 April 2010 to set up the Bergschaden Braunkohle NRW reclamation service for damage victims in the Rhenish lignite mining area. The former chairman of the Higher Regional Court Hamm Gero Debusmann was appointed chairman of the recourse office. In November 2012 and March 2013,

860-488: The deepest point of the Hambach open-pit mine forms the deepest artificial depression in North Rhine-Westphalia. Since 1995, the giant bucket-wheel excavator Bagger 293 is used to remove the overburden. It holds several Guinness records for terrestrial vehicles. The open-cast mine annually produces a spoil amount of 250 to 300 million m³. The ratio of overburden to coal is 6.2:1. The extracted lignite

903-472: The environment. The dumps are usually fenced off to prevent livestock denuding them of vegetation. The open pit is then surrounded with a fence , to prevent access, and it generally eventually fills up with ground water . In arid areas it may not fill due to deep groundwater levels. In Germany, the world's largest producer of lignite (virtually all of which these days is mined open-pit), the former mines are usually converted to artificial lakes . To mitigate

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946-429: The hole. The interval of the benches depends on the deposit being mined, the mineral being mined, and the size of the machinery that is being used. Generally, large mine benches are 12 to 15 metres thick. In contrast, many quarries do not use benches, as they are usually shallow. Mining can be conducted on more than one bench at a time, and access to different benches is done with a system of ramps. The width of each bench

989-454: The mine by 10 to 15 years. One technique used in depressurization is annealing. Annealing is the slow heating and cooling of a metal, alloy or glass. This slow heating and cooling relieves the internal stress of surrounding areas. Annealing will increase a material's workability and durability, which overall increases open-pit mine safety. When groundwater pressures cause problems in open-pit mines, horizontal drains are used to aid in accelerating

1032-450: The mine floor due to excessive uplift pressure. A groundwater control system must be installed to fix problems caused by hydrology. The formation of an appropriate open-pit slope design, changes throughout the life of a mine. It is based mainly on an ever-increasing understanding of the rock mass conditions, including groundwater and associated pressures that may be acting within the slopes. The reduction of groundwater related to pore pressures

1075-471: The open pit is the Sophienhöhe spoil tip, which is considered to be the largest human-made hill, towering over the flat landscape by 200 metres. From 2013, the open-pit area is to be extended southeast. For this, the villages of Morschenich  [ de ] and Manheim  [ de ] must be relocated. The A4 motorway and the Hambach industrial spur, by which the lignite is transported to

1118-616: The open pit with a hot air balloon, occupied an excavator for several days, and painted it partly pink. On 13 May 2009, the joint activity of the local action group of citizens' initiatives against the relocation of the A4 and Friends of the Earth Germany (BUND) failed before the Federal Administrative Court. The plaintiffs tried to stop the relocation of the A4, which was deemed necessary for the planned extension of

1161-487: The open-pit mine and justified this, inter alia, with feared noise pollution, as well as the possible threat to the protected Bechstein bat and other species. In 2009, construction of the new section of motorway began. In September 2014, it was opened to traffic. Since 2008, there have been increasing complaints about possible damage to the hill in the Elsdorf-Heppendorf area. Since the burden of proof lies with

1204-497: The overburden was being transported by conveyor belt to refill the now-exhausted Bergheim mine. Due to the accumulation of about 1 km of material at the Sophienhöhe and the extracted coal, a residual hole was created, which is set to be filled with water after the completion of mining activities. In addition to complete flooding, a pumped-storage power plant is also an option on the site. A patent from 1995 states that such

1247-577: The police cleared tent and hut camps of mining opponents in the remaining Hambach Forest. In 2012, a squatter had to be fetched from a six-metre deep tunnel and the following year, two activists were roped off a tree platform. Later, a new camp was built at another location in the Hambach Forest. In September 2018, a journalist died after falling from the tree structures built by activists. Open-pit mining Open-pit mines are used when deposits of commercially useful ore or rocks are found near

1290-617: The power plants, which could thus continue to be used. RWE Power AG announced in May 2020 that photovoltaic projects for the Sophienhöhe are conceivable. Andreas Pinkwart , Minister for Economic Affairs, Innovation, Digitisation and Energy of North Rhine-Westphalia, also expressed his support for the project. Since around 2012, an area within the remaining part of the Hambach Forest has been occupied by environmentalists to prevent its planned destruction by RWE. The occupation involves

1333-474: The power stations, were laid around three kilometres to the south, parallel to the Cologne-Aachen railway line. In addition, a small piece of the federal highway 477 was moved east. The open-pit mine was put into operation in 1978. Every year, about 0.3 cubic kilometres are moved, so that coal and soil with a volume of about 18.6 km will be mined by the time the coal runs out in 2040. By April 2009,

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1376-446: The presence of unextracted sulfide minerals , some forms of toxic minerals in the gangue , and often cyanide which is used to treat gold ore via the cyanide leach process . If proper environmental protections are not in place, this toxicity can harm the surrounding environment. Open-pit mining involves the process of disrupting the ground, which leads to the creation of air pollutants. The main source of air pollutants comes from

1419-407: The problem of acid mine drainage mentioned above, flooding is often done with the water of nearby rivers instead of using groundwater alone. In some cases, calcium oxide or other basic chemicals have to be added to the water to neutralize the pH -value. Gold is generally extracted in open-pit mines at 1 to 5 ppm (parts per million) but in certain cases, 0.75 ppm gold is economical. This

1462-473: The remaining area between 2018 and 2020. This plan was met with massive protests in the autumn of 2018 and was temporarily stopped in October 2018 by the supreme administrative court of North Rhine–Westphalia (Oberverwaltungsgericht für das Land Nordrhein-Westfalen). Begun in 1978, the mine's operation area currently (as of end of 2017) has a size of 43.8 km, with the total area designated for mining having

1505-404: The rocks are, and the type of rocks involved. It also depends on the amount of structural weaknesses occur within the rocks, such as a faults , shears , joints or foliations . The walls are stepped. The inclined section of the wall is known as the batter, and the flat part of the step is known as the bench or berm. The steps in the walls help prevent rock falls continuing down the entire face of

1548-412: The slope depressurization process. Which helps to prevent large scale slope failure in the mine. Horizontal drains are used to lower pore pressure by reducing groundwater head, which enhances slope stability. A form of open-cast quarrying may be carried out as 'untopping'. This is done where a previous underground mine is becoming uneconomic or worked-out, but still leaves valuable rock in place, often as

1591-558: The surface where the overburden is relatively thin. In contrast, deeper mineral deposits can be reached using underground mining. Open-pit mining is considered one of the most dangerous sectors in the industrial world . It causes significant effects to miners' health, as well as damage to the ecological land and water. Open-pit mining causes changes to vegetation, soil, and bedrock, which ultimately contributes to changes in surface hydrology, groundwater levels, and flow paths. Additionally, open-pit produces harmful pollutants depending on

1634-416: The transportation of minerals, but there are various other factors including drilling, blasting and the loading and unloading of overburden. These type of pollutants cause significant damage to public health and safety in addition to damaging the air quality. The inhalation of these pollutants can cause issues to the lungs and ultimately increase mortality. Furthermore, the pollutants affect flora and fauna in

1677-517: The type of mineral being mined, and the type of mining process being used. Miners typically drill a series of test holes to locate an underground ore body. From the extracted samples, they can determine the extent of the ore. This helps them determine the likely location of the veins or benches of ore and its commercial value. Open-pit mines that produce building materials and dimension stone are commonly referred to as quarries . Open-cast mines are dug on benches , which describe vertical levels of

1720-466: The wall. In some instances additional ground support is required and rock bolts , cable bolts and shotcrete are used. De-watering bores may be used to relieve water pressure by drilling horizontally into the wall, which is often enough to cause failures in the wall by itself. A haul road is usually situated at the side of the pit, forming a ramp up which trucks can drive, carrying ore and waste rock. Open-pit mines are typically worked until either

1763-526: Was accompanied by the resettlement of local villages and towns and the largest forest area in the region, the Hambach Forest, was largely cleared. On 17 January 1984, the first brown coal was mined. Hambach is the largest open-pit mine in Germany, with an area of 3,389 hectares (as of 2007), with an approved maximum size of 8,500 hectares. About forty million tons of lignite are produced annually in this mine. It has recently been estimated that 1,772 million tons of lignite are still available for mining. The lignite

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1806-524: Was achieved by bulk heap leaching at the Peak Hill mine in western New South Wales , near Dubbo , Australia . Nickel , generally as laterite, is extracted via open-pit down to 0.2%. Copper can be extracted at grades as low as 0.11% to 0.2%. Open-pit mining is a common method to extract minerals and samples from the Earth. Due to being cost-effective, this method is very popular and is used all over

1849-642: Was created from extensive forests and bogs, which developed in the Lower Rhine Bay between thirty and five million years ago. The geology of the Lower Rhine Bay is characterized by long-lasting subsidence movements in the last thirty million years, which led to the deposition of up to 1,300 m-thick sediment layers through the North Sea and many rivers. This today consists of lignite seams up to 100 m thick. At 299 m below sea level,

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