Crushed stone quarries. Diamond quarry Diavik. Basic concepts and definitions

The most ancient, but still relevant to this day, mining technology is open-pit mining. Already in Ancient Egypt they knew what a quarry was, and the first open-pit mine workings are known to us from the Paleolithic era. In the ancient world, a similar technology was used to extract marble. The greatest successes were achieved by the builders of Ancient Greece.

Until the 20th century, this method of extracting sand, marble, stone, coal, chalk, limestone and other building materials was the leading one in the world. This is due to the lack of high-performance equipment for opening the upper layers of the lithosphere and removing mineral deposits directly. The relevance of quarries has remained to this day, but the share of their participation in the mining industry has decreased somewhat.

Advantages of quarries

In order to understand what a quarry is, you need to get acquainted with the open-pit mining method. The essence of this method is that resources are extracted directly from the surface of the earth by opening the upper layers of the lithosphere. And the collection of mine workings or enterprises is called a quarry.

Quarrying has a number of advantages compared to obtaining minerals underground:

1. High degree of security.
2. More comfortable conditions for workers.
3. Ease of organization of work.
4. Short construction time.
5. Low capital investment.
6. More complete resource extraction.

But what does this quarry not allow to once again become the main place of mining? The main factor can be called a decrease in economic benefits: the longer the earth's surface is mined, the deeper the quarry becomes, which increases the cost of delivering material to processing plants. At this stage of development of the mining industry, this is the main barrier to the development of open-pit mining.

Basic elements of a quarry

The easiest way to imagine a quarry is in the form of a cone, the top of which is immersed in the earth's surface. Inside such a “cone” you can see spiral ramps, which are formed by ledges. The main elements that can characterize any quarry, be it a stone or a sand quarry, are:

1. The bottom of the quarry is the surface of the lower ledge, which is also called the bottom. If morphologically complex and extended rocks are being mined, the bottom may have a stepped structure.
2. Pit depth is the distance of the top cut to the lowest point of the mining operation. This value can reach 1000 meters.
3. Maximum depth - the maximum distance from the top edge to the bottom contour at which mining is economically feasible.
4. Limit contour - the contour of the quarry for the period of its closure due to low economic efficiency.

The main element, without which it is impossible to imagine what a quarry is, is a ledge. Its main characteristics - height, angle of repose, dimensions of the upper and lower working platform - depend on the massiveness and value of the rocks being mined.

Extraction technology

Open-pit mining is carried out by two types of work - stripping and mining. At the first stage, the earth's surface is "opened" - the top layer of the lithosphere is cut off, a pit is dug, thereby opening access to minerals. Then they begin directly to extract resources.

As the layers of “earthly wealth” are mined, the diameter and depth of the quarry increase, and the working ledges move from the center to the edges. Obtaining almost any type of resource involves drilling and blasting. Depending on the local conditions, their share can be 25-30% of the cost of the extracted material.

Economic efficiency

When developing marble, limestone rocks, or creating any open-type mining, including a sand quarry, they strive to reduce costs. For this purpose, rotary excavators and heavy-duty vehicles are used: mainly BELAZ vehicles, which reduces transportation costs.

Often, the open-pit method of mining underground resources is used to produce coal. At the same time, it is possible to reduce the costs associated with delivery directly to consumers, which makes it accessible to the general public. In addition, the open-pit method of coal mining is the safest, but the quality of the raw materials leaves much to be desired due to the presence of a large number of impurities.

The influence of quarries on the environmental situation

Quarry development has a negative impact on the ecological situation of the developed area. Firstly, the top fertile layer of the earth is completely destroyed, which subsequently cannot be restored. Secondly, the hydrogeological conditions of the site and the terrain change significantly.

Thirdly, the land allocation area is polluted by generated waste and wastewater. In addition, one cannot ignore the noise impact on the environment, as well as the release of large amounts of carbon monoxide. Similar negative effects are observed when both a granite quarry and any other open-pit mine are created.

Creating artificial islands or destroying natural mountains: people are constantly changing the face of the planet. And the miners cope excellently with this task by changing ever larger areas of the landscape. Some pits dug by crushers in an attempt to extract ore are true marvels of technology, and the largest of them are visible from space.

Some of these amazing examples of human ability to subjugate nature are created in the form of open pits. This mining method is used when resources lie too close to the surface and the soil composition does not allow tunneling. Through the efforts of miners, careers grow until resources are exhausted. After the quarries are depleted, they turn into landfills or artificial lakes, but despite this they continue to amaze the imagination with their scale. We invite you to see the best of the largest quarries in the world.

Diamond tube "Mir"

Owner: Alrosa
Resources: diamonds
Location: Russia, Mirny
Development started in 1957

Currently, it is the second largest man-made crater in the world. This diamond mine is located in Russia, near the city of Mirny. “The World” is so huge that flights are prohibited over it, since the mine workings create a very strong downdraft of air. The quarry, whose development began in 1957, produced up to 10 million carats of diamonds per year until its closure in 2011. "The World" was notorious for its terrible conditions. In winter, the temperature in the quarry drops so much that it freezes engine oil and rubber, and leads to the gradual collapse of the quarry. By the time the mine was closed, the time it took to lift the car from the bottom of the quarry to the surface had reached 2 hours.

Diamond tube "Davik"

Owner: Rio Tinto (60%), Harry Winston Diamond Corporation (40%)
Resources: diamonds
Location: Canada
Development started in 2003

The Diavik diamond pipe is located in Canada and is no less impressive than the Mir, despite the fact that it is significantly smaller than its Russian counterpart. Diavik produces 8 million carats of diamonds per year, and the development of the mine began in 2003. It is most notable for the fact that it is located on the island of Lac De Grace, which allows you to observe amazing metamorphoses: in the summer the quarry is surrounded by crystalline water, and in winter it is shrouded in an icy desert. There is a winter road leading to Diavik - the seasonal road is accessible only two months a year, it stretches along the surface of a frozen lake 375 km north of Yellowknife. The rest of the time, you can only get to Diavik by air.

Bingham Canyon

Owner: Rio Tinto
Resources: copper
Location: Utah, USA
Development started in 1904

Visible from space and also known as Kennecott, the Bingham Canyon copper mine is the deepest mine in the world. The discoverers of the mine were the Mormons - who discovered it in the mid-19th century, at that time the deposit reached 1.2 km deep, 2.5 miles wide and occupied an area of ​​more than 7.7 km 2. Surprisingly, despite the fact that the quarry is being developed since 1904, production at the field is expected to continue until 2030.

Calgory Super Pit

Owner: Kalgoorlie Consolidated Gold Mines
Resources: Gold
Location: Calgory, Australia
Development began in 1989.

The Phemiston Open Pit gold mine is the largest gold mine in the world and is commonly referred to as the Super Pit. The oblong-shaped section is located in western Australia, reaches 3.5 km in length, 1.5 km in width and drops to a depth of more than 320 meters. Super Pit produces more than 850 thousand ounces of gold per year.

Hal-Rust-Mahoning Quarry

Owner: Hibbing Taconite
Resources: Iron Ore
Location: Minnesota, USA
Development started in 1893

The Mahoning quarry began to be developed as an underground mine, but the iron ore turned out to be too close to the surface and the development had to be carried out using an open pit method. Now the Mahoning quarry reaches 8 km in length, 3.2 km in width and 180 meters in depth. During the development of the field, it was decided to combine several smaller workings into one large quarry. For such a “merger” it was necessary to move the city of Hibbing, located in close proximity to the quarries. Relocating the city took 2 years and $16 million, during which time nearly 200 residential buildings and 20 office buildings were moved. At its peak between World War I and World War II, the mine produced 14 percent of all iron ore produced in the United States. Today, almost 100 years later, the Hibbing Taconite Company still uses Mahoning for mining.

Toquepala

Owner: Southern Copper Corporation
Resources: Copper
Location: Tacna, Peru
Development started in 1960

The Andes are home to several of the world's largest mines. Toquepala reaches 700 meters in depth, and the diameter reaches more than 2.5 km. Looking at the photograph taken by a NASA satellite, you can see the giant rock dumps that have formed artificial mountains along the northern part of the mine.

Diamond pipe "Ekati"

Owner: BHP Billiton
Resources: Diamonds
Location: Northwest Canada
Development started in 1998

Ekati is located 300 km from Yellowknife, and was discovered during the gold rush. Since the project opened in 1985, lands from the Great Lakes to the Arctic Circle have been resold like geological lottery tickets. The scientific discovery that proved that kimberlite pipes are a sign of a diamond deposit made Yekati another Jack later in this lottery.

Kimberley Quarry

Owner: Da Beers
Resources: diamonds
Location: Kimberley, South Africa
Development started in 1871

The name - Giant Hole - is what really lets your imagination run wild. The section, 240 meters deep, is the largest mine in the world where mining was carried out manually. The field was originally owned by the Da Beer brothers, which led to a battle over patent licenses with Hal-Rust-Mahoning.

After 16 years of excavations in extremely harsh conditions, small quarries located in the region came to the decision to create a conglomerate, and unite all workings in one company, Da Beers Consolidated Mines Limited. After lying abandoned for more than 100 years, the mine was turned into a UNESCO World Heritage Site.

Grasberg Quarry

Owner: Freeport-McMoRan
Resources: copper, gold
Location: Papua, Indonesia
Development started in 1990

The Grasberg deposit is the largest gold mine in the world and the third largest copper mine. Grasberg's turbulent past includes dozens of expeditions, a rebel attack and $55 million in over-budget construction.
In the 1930s, a Dutch scientific expedition set out to explore one of the highest peaks in the Dutch East Indies. The expedition report reported the discovery of reserves of gold and copper, which later became the Ertsberg Quarry. Due to inaccessibility - the field is located in a mountain range at an altitude of more than 4,100 meters above sea level - construction costs were estimated at $175 million; the project involved the construction of 116 km of roads, an airstrip, a power plant and a port. In 1977, a group of rebels attacked the mine and caused sabotage by planting explosives on the railway line.

Ten years after the attack, Freeport concluded that production had been depleted and began exploring the area around the field in hopes of producing smaller associated deposits. The company hit the jackpot at the Grasberg deposit, located 3 km from Ertsberg with maximum copper reserves of $40 billion. In the aerial photographs below you can see what Grasberg looks like now. And although Östberg began to be developed in the 30s and about $175 million was invested in it, it is too small to be visible.

Chuquicamata

Owner: CODELCO
Resources:: copper, gold
Location: Chile
Development started in 1882

If we talk about volumes, you will not find production larger than the Chilean Chuquicamata. Having moved to the state property after the Chilean nationalization of 1970, the workings reached 4.3 km long, 3 km wide and almost 900 meters deep.

For a brief period, Chuquicamata held the largest annual production volume. Prior to its merger with the Escondida quarry in 2002, the quarry operated the largest smelter and largest electrolytic refinery in the world. It is obvious that the area in the mine area was used for many hundreds of centuries; 17 years after the start of work, a “copper man” dating back to 500 BC was discovered in a blocked temporary working.

Escondida

Owner: Minera Escondida
Resources: Copper
Location: Atacama Desert, Chile
Development started in 1990

Escondida produces more copper than any other quarry in the world. In 2007, Minera Escondida produced more than 1.5 million tons of copper worth more than $20 billion. Construction of the quarry began after studies showed a high probability of the existence of a copper belt in the region, just 300 km from the Chuquicamato quarry.

Berkeley Pete

Owner: Atlantic Richfield Company
Resources: copper, silver, gold
Location: Montana, USA
Development started in 1955

The development of the mine was stopped 30 years ago. Since then, without water pumps to keep the quarry open, the 540-meter pit has filled with rainwater. Despite the fact that the water appears crystal clear from above, in fact it contains a real soup of heavy metals and dangerous chemical elements - such as arsenic, sulfuric acid and cadmium. In fact, the water in the quarry is so rich in minerals that Montana Resources extracts 180 thousand tons of copper per month pumping water into the surrounding ponds.

The mine opened in 1955, production was in the region of 1 billion tons of resource and subsequently grew so much that the owner of the Anaconda deposit bought a neighboring city to continue expansion.

Yuba Goldfields

Owner: Western Aggregate
Resources: Aggregated
Location: California, USA.
Development started in 1848

Yuba Goldfrieds is located along the Yuba River in California. The deposit was established during the gold rush of 1848-55. Being located in the river bed, the mine was in its infancy, but as soon as word spread about the prospects of the region, large mining companies began to actively invest in projects in the region. To minimize production, companies began opening mines using the pressure of water jets in the foothills of the Sierra Nevada. Soon, so much waste and debris was dumped into the river that the river bed rose 100 feet and in some areas destroyed and flooded communities in the river area.

The area has now exhausted its gold reserves and although it is still used for the extraction of concrete components, there are plans to turn it into a nature reserve. Yuba Goldfrieds are known for their unusual appearance, when looking at aerial photography you can see how mountains, streams, and pits created under the influence of many years of mining - like a gut, stretch along the river bed.

Diamond pipe “Udachnaya”

Owner: ALROSA
Resources: Diamonds
Location: Republic of Sakha, Russia
Development started in 1988

The depth of Udachnaya reaches more than 600 meters, although it is not as wide as Mir. Discovered a little later than Mir, Udachnaya is so remote from civilization that the project had its own small town built for the mine workers, named after the deposit. Since 2010, Alrosa has changed the type of mining at the mine to underground, since open-pit mining has become no longer profitable.

Olympic Dam

Owner: BHP Billiton
Resources: copper, gold, silver, uranium
Location: South Australia
Development started in 1988.

Although BHP Billiton's underground mine has plans to expand into the world's largest open pit mine, it already stretches a long way from what was once Roxby Downs Ships station. Imagine that this deposit contains tons of copper, uranium, gold and silver.

Olympic Dam has the world's fourth largest copper reserve and is the world's largest uranium deposit. Even without expanding the area of ​​the Olympic Dam quarry, it consumes 35 million liters of water daily.

When using such concepts as “mine”, “mine” and “mine”, there is usually no difficulty in determining whether an object belongs to the extraction of a type of natural resource. What is a quarry? Is this also an artificial industrial facility or is it still a natural depression?

Definition

A quarry is an artificially formed excavation in the surface of the earth’s crust for the extraction of an underlying layer of natural resources using an open sampling method. As a rule, it has a funnel shape, tapering downward. The territory is limited by the formed planes. At the initial stage of development, the top layer of soil is removed and moved outside the mining zone.

The concept of “quarry” arose from the word carriere, borrowed from the French language, which was used to designate places where natural stone was mined and processed. It can also be used to highlight the specialization of an enterprise whose activities are related to open-pit mining of natural resources.

Varieties

Excavation using a closed method without removing the top layer is usually called a mine. In open-pit coal mining, the term open pit is used. When mining minerals to extract metal ores and crystals, the concept of a mine (mine) is more often used.

In all cases, we can say that a quarry is an open-pit mine for industrial sampling of rock that lies at depth. Depending on the deposit, it can be sand, clay, gravel, limestone. Extraction of fossil fuels is carried out in peat, shale, and coal quarries. For the chemical industry, samples are made to extract phosphites, apatites, sulfur, arsenic and other salts from the depths of the planet. Non-metallic materials include quarries for the extraction of alabaster, talc, and mica.

Metals are extracted from ore. Its extraction is most often also carried out using the quarry method. This is how raw materials are extracted for the production of ferrous metals (iron, manganese, chromium) and non-ferrous metals (copper, zinc, tin). The same principle is used to sample ores of noble, radioactive and rare earth metals. A mining and processing plant is usually built near such deposits.

Granite mining

The method of opening depends on the nature of the deposit. Typically a vertical trench is used, directed into the excavation. The peculiarity of the quarries is that the material is used to make facing stones and blocks. The main task is to ensure maximum safety of the monolith of extracted blocks.

Granite has the property of splitting along the plane of the rock. This feature is used in wedge mining. Several technological methods are used. The simplest is drilling a well and then planting explosives. During blasting, the rock is exposed. Large pieces are used for cutting slabs. The disadvantage of this method is the large amount of waste that goes into crushed stone. In large parts, the likelihood of microcracks, which will appear during processing, increases. A more gentle method is to pump compressed air into the borehole, which leads to cracking of the formation.

Granite quarries at the preparation stage during field development are cheaper than marble ones. But during the production process, due to complex technology, the cost of production increases. The best results in terms of product quality are obtained by cutting the rock layer directly into blocks. But this option is the most expensive.

Intensive construction requires a lot of concrete. Sand is an indispensable component in its composition. The presence of deposits of this material at shallow depths in close proximity to the city limits has a positive effect on construction costs. When assessing a deposit, the chemical composition (SiO 2 content), the presence of impurities, fire resistance, rock structure, and its physical and mechanical properties are taken into account.

The shallow depth of the deposit makes it possible to open the deposit using wheeled equipment: scrapers, bulldozers. Sampling is carried out by draglines and multi-bucket excavators, and transportation is carried out by road. A sand quarry is a relatively shallow excavation (up to 15 m). The peculiarity is that the material is free-flowing. It is not possible to ensure the stability of frontal dumps due to the danger of collapses. Another feature is the likelihood of groundwater flooding, which requires its diversion or the use of “wet” extraction technology.

May 26th, 2016

Somehow, probably half a year ago, everyone seriously rushed to discuss mining projects on asteroids. They planned how they would pick them, and some even wanted to collect them in traps and transport them to Earth. But it’s not for nothing that they say that we still don’t know enough about our planet, and especially about the World Ocean.

As mineral resources on land become depleted, their extraction from the ocean will become more and more important, since the ocean floor is a colossal, almost untouched storehouse. Some minerals lie openly on the surface of the seabed, sometimes almost close to the shore or at relatively shallow depths.

In a number of developed countries, reserves of ore, mineral fuels and some types of construction materials have become so depleted that they have to be imported. Huge ore carriers ply across all oceans, transporting purchased ore and coal from one continent to another. Oil is transported in tankers and supertankers. Meanwhile, there are often sources of mineral resources very close by, but they are hidden under a layer of ocean water.

Let's see how it will be mined in the future...

Photo 2.

Closer to the outer edge of the shelf, nodules containing large amounts of phosphorus have been found in many parts of the world's oceans. Their reserves have not yet been fully explored and calculated, but, according to some data, they are quite large. Thus, off the coast of California there is a deposit of about 60 million tons. Although the phosphorus content in the nodules is only 20-30 percent, its extraction from the seabed is quite economically profitable. Phosphates have also been found on the tops of some seamounts in the Pacific Ocean. The main purpose of extracting this mineral from the sea is to produce fertilizers; but, in addition, it is also used in the chemical industry. Phosphates also contain a number of rare metals as impurities, in particular zirconium.

In some areas of the shelf, the seabed is covered with green “sand” - an aqueous oxide of iron and potassium silicates, known in mineralogy as glauconite. This valuable material is used in the chemical industry, where potash and potash fertilizers are obtained from it. Glauconite also contains rubidium, lithium and boron in small quantities.

Sometimes the ocean presents the researcher with absolutely amazing surprises. Thus, near Sri Lanka, at a depth of thousands of meters, accumulations of barite nodules were discovered, three-quarters consisting of barium sulfite. Despite the great depth, the development of the deposit promises significant benefits, since the chemical and food industries are constantly in need of this valuable raw material. Barium sulfite is added as a weighting agent to clay solutions when drilling oil wells.

In 1873, during the English expedition around the world on the Challenger, strange dark “pebbles” were raised from the bottom of the ocean for the first time. Chemical analysis of these nodules showed a high content of iron and manganese. It is currently known that they cover significant areas of the ocean floor at depths from 500 meters to 5-6 kilometers, but their largest accumulations are still concentrated deeper than two to three kilometers. Ferromanganese nodules have a round, cake-shaped or irregular shape with an average size of 3-12 centimeters. In many areas of the ocean, the bottom is completely covered with them and resembles a cobblestone road in appearance. In addition to the two indicated metals, the nodules contain nickel, cobalt, copper, molybdenum, that is, they are multicomponent ores.

According to recent estimates, the world reserve of iron-manganese nodules is 1,500 billion tons, which far exceeds the reserves of all currently developed mines. The deposits of ferromanganese ore are especially large in the Pacific Ocean, where the bottom is in some places covered with nodules in a continuous carpet and in several layers. Thus, in terms of providing iron and other metals, humanity has very favorable prospects; All that remains is to establish production.

This was first started in 1963 by an American company that previously specialized in shipbuilding. With a good manufacturing base at their disposal, shipbuilders created a device designed to collect nodules at relatively shallow depths and tested it off the coast of Florida. The technical side of the enterprise completely satisfied the designers - they achieved production of nodules on an industrial scale from a depth of 500-800 meters, but the business turned out to be unprofitable economically. And not at all because ore mining was too expensive. The trouble was different - it turned out that shallow Atlantic nodules contain much less iron than in similar deposits in the depths of the Pacific Ocean.

An ingenious method that allows one to lift nodules from the ocean floor without great expense was proposed by the Japanese. There are no collectors, pipes, or powerful pumps in their design. The nodules are collected from the bottom of the sea using wire baskets, similar to those used in supermarkets, but, of course, more durable. A series of such baskets are attached to a long cable, shaped like a giant loop, the upper part of which is on the ship, and the lower part touches the bottom. With the help of the ship's winch drum, the cable continuously moves up in the bow of the ship and runs out to sea behind its stern. The baskets attached to it pick up the nodules from the bottom, bring them to the surface and dump them into the hold, after which they are lowered for a new portion of ore. The system gave good results at depths of up to 1,400 meters, but it is also quite suitable for working at a depth of 6 kilometers.

In the minds of the inventors, another, at first glance, absolutely fantastic design was born, which already exists in the drawings, but has not yet been brought to life. Typically, nodules lie on more or less level and sufficiently hard ground that allows a crawler scraper to be driven over it. Having filled the ballast tanks with sea water, the scraper sinks to the bottom and crawls along it on caterpillars, raking concretions with a wide knife into a voluminous bunker. Energy for operation is supplied via cable from the vessel, and control is carried out from there, with the operator guided by the underwater television system. Once the bunkers are full, water is removed from the ballast tanks and the scraper is raised to the surface. With modern technical capabilities, it is quite possible to build such a machine. Here it is appropriate to emphasize once again that the design of underwater industrial enterprises of the future is very far from creating the notorious underwater cities.

Among the richest offshore deposits that are being successfully developed today are titanomagnetite sands off the coast of Japan and tin-bearing (cassiterite) sands off Malaysia and Indonesia. The underwater tin ore deposits are a shelf extension of the world's largest onshore tin belt, stretching from Indonesia to Thailand. Most of the explored reserves of this tin are concentrated in coastal valleys and their underwater continuation. Heavier productive sands, containing from 200 to 600 grams of tin per cubic meter of rock, are concentrated in depressions in the area. As shown by the results of drilling at sea, their thickness in some places reaches 20 meters.

Far beyond the Arctic Circle, at 72 degrees north latitude, on Vankina Bay of the Laptev Sea, our country’s first floating tin mining enterprise has recently been put into operation. Tin-bearing soil is extracted from a depth of up to 100 meters by a dredger capable of mining not only in clean water, but also under ice. Primary processing of the rock is carried out by a floating processing plant located on one of the vessels of the flotilla. The Polar Plant can operate year-round.

The development of underwater placers produces a significant amount of diamonds, amber and precious metals - gold and platinum. Like tin ores, these placers serve as a continuation of the land ones and therefore do not go far under water.

The only platinum deposit in the United States is located on the northwest coast of Alaska. It was discovered in 1926 and began to be exploited the following year. Prospectors, moving along small rivers, came close to the coast, and in 1937 work began directly in the bay. The depth from which rock containing grains of platinum is extracted is constantly increasing.

The sea placers of Australia and Tasmania, stretching for more than a thousand kilometers, are world famous. Platinum, gold and some rare earth metals are mined here.

In some cases, marine placers are characterized by a much higher content of valuable minerals than similar deposits on land. Waves constantly agitate and mix the rock, and the current carries away lighter particles, causing the sea to act as a natural enrichment factory. Off the coast of South India and Sri Lanka there are thick ilmenite and monocyte sands containing iron-titanium ore and phosphates of the rare earth elements cesium and lanthanum. A multi-kilometer strip of enriched sand can be traced in the sea at a distance of up to one and a half kilometers from the coast. The thickness of its productive layer in some places reaches 8 meters, and the content of heavy minerals sometimes reaches 95 percent.

One of the largest diamond deposits, as is known, is located in South Africa. In 1866, a little girl from a poor Dutch village, playing on the banks of the Orange River, found a sparkling pebble in the sand. The visiting gentleman liked the toy, and the girl’s mother, Madame Jacobe, gave the guest a shiny trinket. The new owner showed the curious find to one of his friends, and he recognized it as a diamond. After some time, Mrs. Jacobs was stunned by the unexpected wealth that fell upon her - she received as much as 250 pounds sterling, exactly half the cost of the shiny stone her daughter found.

Soon South Africa was struck by diamond fever. Now, income from the development of diamond mines constitutes a very significant item in the South African budget. Surveys in 1961 showed that diamonds are found in alluvial deposits consisting of sand, gravel and boulders, not only on land, but also underwater at depths of up to 50 meters. The first sample of sea soil weighing 4.5 tons contained 5 diamonds worth a total of $450. In 1965, almost 200 thousand carats of diamonds were mined from the sea in this area, a hundred years after the discovery of the first diamond.

50-60 million years ago, northern Europe was covered with continuous coniferous forests. Four species of pine and one species of fir grew here, which no longer exist. Resin flowed from cracks in the tree bark down powerful trunks. During floods, its frozen drops and lumps fell into rivers and were carried out to the sea. Over the centuries, the resin hardened in salt water, turning into amber.

The most powerful placers of amber are located on the coast of the Baltic Sea near Kaliningrad. Beautiful yellow “stones” are hidden from view in bluish fine-grained glauconitic sands of marine origin, on top of which later strata have formed. Where the amber-bearing layer reaches the sea, the surf constantly destroys it, and then pieces of rock fall into the water. Waves easily wash away the sand and clay lumps and release the amber contained in them. Being only slightly heavier than water, in calm weather it falls to the bottom, but in the weakest waves it begins to move.

Like any other light objects, amber is sooner or later thrown onto the beach by the waves. This is where the ancient inhabitants of the Baltic coast found it. Phoenician ships sailed to the amber coast and took away a huge amount of exchanged “electron”. Archaeological finds make it possible to trace the long route along which amber and products made from it, thanks to barter, reached from the Baltic Sea to the Mediterranean.

The jewelry value of amber has survived to this day. The best, transparent and large pieces are selected for products, while the bulk of small amber is used in industry. This material is used to make high-quality varnishes and paints, is used as an insulator in the radio industry, and is used to prepare biostimulants and antiseptics. A modern amber plant is a mechanized enterprise where the rock is washed and enriched, and the extracted valuable material is sorted and subjected to further processing. In 1980, an amber museum was created in Kaliningrad, which displays products made from this material and unique finds.

Some mineral deposits are hidden in the depths of the seabed. Their development is technically more difficult compared to placers. In the simplest case, the opening of the ore layer is carried out from the shore. For this purpose, a vertical shaft of the required depth is drilled, and then horizontal or inclined passages are laid towards the sea, along which they reach the deposit. This can be done when the development site is located near the coast. Similar mines, the faces of which are located under the seabed, exist in Australia, England, Canada, the USA, France and Japan. They mainly mine coal and iron ore. One of the world's largest "offshore iron ore" mines is located on a small island in the Strait of Belle Isle. Some of its sections go far from the shore, and above the faces there is a 300-meter layer of rock and a hundred-meter layer of water. The mine's annual production is 3 million tons.

It is estimated that the seabed off the coast of Japan stores at least 3 billion tons of coal, and 400 thousand tons are extracted from this reserve every year.

If a deposit is discovered far from the coast, it is not economically profitable to open it using the described method. In this case, an artificial island is poured and minerals are penetrated through its thickness. Such an island was created in Japan at a distance of two kilometers from the coast. In 1954, a vertical shaft of the Miki mine was laid through it.

Experience in the construction of underwater tunnels allows them to be used not only as transport arteries, but also to get closer to mineral reserves along the seabed. The finished reinforced concrete sections of the tunnel are laid on the bottom and the shaft excavation begins from the last section.

At a significant distance from the shore and at sufficient depth, you will have to do without a tunnel. In this case, it is supposed to vertically install a large-diameter reinforced concrete pipe on the bottom and then remove the soil from the inside. As it depletes, the pipe will lower slightly under the influence of its own gravity. There is no need to transport the extracted soil anywhere; it is simply thrown outside, and it will settle around the pipe, creating an embankment that prevents sea water from penetrating into the pipe. Upon completion of construction, miners will be lowered into the mine through this pipe, and ore or coal will be lifted up.

In order not to raise the mined ore to the surface of the ocean, one English company has developed a project for an underwater nuclear ore carrier. Although such a vessel has not yet been built, it has already received the name “Moby Dick” in honor of the legendary white sperm whale described in the novel of the same name by the American writer G. Chalkville. The underwater ore carrier will be able to transport up to 28 thousand tons of ore per voyage at a speed of 25 knots.

The development of minerals hidden in the depths of the seabed requires constant monitoring of water entering the mine, which can easily seep through cracks. The risk of flooding increases in seismically active areas. Thus, in some offshore mines in Japan, it was noticed that after each earthquake, the influx of water increases approximately three times. More attention has to be paid to the possibility of rock collapse, therefore in a number of offshore mines, especially where the faces are separated from the water by a small layer of rock, it is necessary to limit the excavation, leaving part of the ore-bearing layer as supports.

The extensive practical experience gained in extracting oil from the bottom of the sea turned out to be useful in the development of such a completely solid mineral as sulfur, deposits of which are also found in the soil layer on the seabed. To extract sulfur, a well is drilled, similar to an oil well, and a superheated mixture of water and steam is injected into the formation under high pressure. Under the influence of high temperature, the sulfur melts, and then it is pumped out using special pumps.

But what plans are already being actively implemented.

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In the spring of 2018, in the Bismarck Sea at a depth of 1600 m, Nautilus Minerals will begin commercial development of the Solwara 1 hydrothermal copper ore deposit. The commercial success of this project could trigger the process of massive “immersion” of mining companies to the ocean floor in pursuit of colossal mineral reserves.

The idea of ​​thoroughly rummaging through the “Davy Jones chest,” as British sailors call the ocean depths, is not new. The first who managed to put his hand into the bins of the sea devil was the Scottish engineer George Bruce, who in 1575 built a coal mine in the middle of Culross Bay with a waterproof headframe and a caisson-type mouth. And although in 1625 Davy Jones returned his, sending a storm of unprecedented force to Culross, which overnight smashed Bruce's brainchild into pieces, the technology quickly spread throughout the Old World. In the 17th-19th centuries, from Japan to the Baltic, coal, tin, gold and amber were mined in the sea using the Bruce method.

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Diamonds from sand porridge

At the end of the 19th century, when powerful steam engines appeared in the arsenal of miners, a simple and flexible “horizontal” scheme for underwater gold mining was developed in Alaska using floating dredge pumps, dredges and dinghy barges onto which the rock was unloaded. Over time, due to the use of heavy special equipment for underwater work, the possibilities of horizontal mining have expanded significantly. Today, in shallow sea waters, everything from construction gravel and iron ore to rare earth monazite and precious stones is mined in this way.

For example, in Namibia, the De Beers company has been successfully extracting diamonds for more than half a century from sandy deposits, which for millions of years were carried to the shores of the Atlantic by the waters of the Orange River. At first, production was carried out at depths of up to 35 m, but in 2006, after the depletion of easily accessible deposits, De Beers engineers had to replace conventional dredgers with floating drilling rigs.

Solwara 1 deep sea quarry
The area of ​​the Solwara 1 site, located on top of an extinct underwater volcano, is small by earthly standards - only 0.112 km2, or 15 football fields. But several thousand such deposits have already been discovered at the bottom of the World Ocean.

In 2015, specifically for the development of the Atlantic 1 concession (depth 100-140 m), Marine & Mineral Projects built for De Beers a new remote-controlled crawler “vacuum cleaner” - a 320-ton electro-hydraulic giant capable of clearing sand from an area two sizes in an hour. football fields. The short process cycle is completed on the support vessel Mafuta, where the precious sludge is continuously fed to a sorting conveyor. Every 24 hours, De Beers private special forces deliver about 700 large diamonds of the highest quality from Mafuta to the mainland.

Photo 5.

However, gold and diamonds are trifles in comparison with the real treasures waiting in the wings of the deep ocean. In the 1970s and 1980s, as a result of large-scale oceanographic research, it became clear that the seabed was literally strewn with giant deposits of polymetallic ores. Moreover, due to the specific conditions of ore formation, the metal content in them is an order of magnitude higher than in deposits on land. True, lifting ore onto land is not an easy task.

The first to try to do this was the German company Preussag AG, which in 1975-1982, under a contract with the authorities of Saudi Arabia, carried out exploration of the Atlantis II Deep basin, discovered in the Red Sea at a depth of over 2 km ten years earlier. Exploration drilling over an area of ​​about 60 km2 showed that the dense “carpet” of mineralized silt up to 28 m thick contains, in terms of pure metal, about 1,830,000 tons of zinc, 402,000 tons of copper, 3,432 tons of silver and 26 tons of gold. In the mid-1980s, in cooperation with the French company BRGM, the Germans developed and successfully tested a “vertical” deep-sea mining scheme, which was broadly copied from offshore drilling platforms.

During testing of the equipment - a suction unit with a hydraulic monitor mounted on a supporting pipeline 2200 m high - more than 15,000 tons of raw materials were lifted onto the auxiliary vessel, the quality of which exceeded the metallurgists' expectations. But due to a sharp drop in metal prices, the Saudis abandoned the project. In subsequent years, the idea was revived many times and again shelved. Finally, in 2010, it was announced that development of Atlantis II Deep, one of the world's largest deep-sea copper-zinc deposits, would begin. When this will happen is unknown. In any case, not before the stainless steel robots of Nautilus Minerals go to visit Davy Jones.

Photo 4.

Washing and rolling

The deal satisfied both parties. The islanders can now count on handsome rents, and the Canadians, having received 17 more licenses for deposits covering an area of ​​450,000 km2 in the Bismarck Sea, have provided themselves with work for the next decade. Today Nautilus is perhaps the only company in the world with sophisticated technology and unique equipment for deep-sea mining. The water-slurry ore mining scheme, adapted by Nautilus engineers to the conditions of Solwara 1, consists of three basic elements: underwater remote-controlled mining equipment, a vertical slurry lifting system and an auxiliary vessel. A key element of the technology is the world's first dedicated deep-sea mining vessel, construction of which began in April 2015 at China's Fujian Mawei shipyard. The 227-meter Nautilus flagship, equipped with a high-precision positioning system with seven tunnel thrusters and six Rolls Royce azimuth steering columns with a total power of 42,000 hp, is expected to roll off the slipways in April 2018. The “shoulders” of this floating mine will support, literally and figuratively, the entire technological cycle of the field: delivery of equipment to the diving point; lowering, lifting and servicing of machines; lifting, draining and storing sludge.

Photo 6.

All underwater technology for Nautilus was developed by the British company SMD. It was planned to create a complex multi-operational combine harvester capable of operating for months in an aggressive environment at zero temperature and enormous pressure. But after consulting with experts from Sandvik and Caterpillar, it was decided to make one specialized crawler robot for each of the three basic operations - leveling the working bench, opening the rock and lifting cuttings up the mountain. “Dry” tests of the steel monsters, worth a total of $100 million, took place in November 2015, and next summer they will undergo a series of tests in shallow water.

The first violin part in this trio is played by the Auxiliary Cutter, equipped with a dual milling ripper on a long rotating beam. Its task is to form a flat platform for the future quarry, cutting off uneven terrain. To maintain stability in areas with a strong slope, the Auxiliary Cutter will be able to use lateral hydraulic supports. Next will be the main “getter” of Nautilus - a heavy cutting machine Bulk Cutter weighing 310 tons with a huge cutting drum. Bulk Cutter function - deep opening, crushing and grading of rock into shafts.

Photo 7.

The most complex operation of the cycle - collecting and feeding the water-sludge mass into the riser-sludge lifter - will be performed by a Collecting Machine “vacuum cleaner”, which is equipped with a powerful pump with a cutting-suction nozzle and connected to the riser with a flexible hose. The geometry and cutting power of the cutting machines are calculated by SMD engineers so that the output is rounded pieces of rock about 5 cm in diameter. This will achieve optimal slurry consistency and reduce abrasive wear and the risk of plugging. According to SMD experts, the Collecting Machine will be able to collect from 70 to 80% of the volume of the exposed rock.

On the ship, the sludge will be stored in holds and then transferred to bulk carriers. At the same time, at the insistence of environmentalists, the “bottom” sludge water will have to be filtered and reinjected to depth. Overall, the Nautilus harvesting scheme poses no more threat to the ocean environment than trawling fisheries. Local deep-sea biological systems, according to scientists, are restored within a few years after the cessation of external influence. Man-made accidents and the notorious human factor are a different matter. But Nautilus has an effective solution here too. All processes on Solwara 1 will be managed by a system developed by the Dutch company Tree C Technology.

If all goes according to plan, the sharp teeth of the mining machine will tear the first ton of rock from the surface of the ancient Solwara volcanic plateau in the spring of 2018. I would like to hope that this “small step” into the abyss that Nautilus dared to take will become a huge step for all of humanity.

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sources
The article “Davy Jones's Chest” was published in the magazine “Popular Mechanics” (No. 162, April 2016).

Open-pit mining is one of the most widely used methods in the world. It is used when mineral deposits are located close to the Earth's surface, and they are simply excavated using large quarry equipment or extracted through a series of controlled explosions.

This is one of the simplest and cheapest mining methods, however, it leaves giant craters on the surface that look very fascinating. Today we want to show you photographs of the ten largest open-pit mines in the world and tell you a little about them.

10. Escondida Copper Mine

Located in the Chilean Atacama Desert, this copper mine consists of two open pits - Escondida Pit and Escondida Norta. Dimensions: 3.9 kilometers long, 2.7 kilometers wide and 645 meters deep. In terms of depth, this is the third quarry of this type in the world.

9. Udachny Diamond Mine

This quarry is located in the Russian part of Eastern Siberia and is one of the largest in Russia. Now managed by the state company ALROSA, it was opened in 1971, and it is planned to close it this year, 2015. But only open-pit mining will stop; underground mining will continue, since according to the company, another 108 million carats of diamonds can be extracted from the ground.

8. Chuquicamata Copper Mine

For more than a century, the Chuquicamata copper mine, located near Santiago, Chile, has produced enormous quantities of copper ore. It is 4.3 kilometers long, 3 kilometers wide and over 850 meters deep, making it the second deepest in the world. In 2018, open-pit mining there will cease and operations will be moved underground, where 1.7 billion tons of copper ore still remain.

7. Grasberg deposit

This "Holy Grail" of quarries is located in the Indonesian province of Papua. It ranks second in the world in gold and copper mining. Its depth reaches 550 meters.

6. Mahoning Mine

This quarry is interesting because mining there began with underground operations and only then came to the surface, although usually everything happens the other way around. This iron mine is called the “Grand Canyon of the North” and is located in the US state of Minnesota. Dimensions: 8 kilometers long, 3.2 kilometers wide and 180 meters deep.

Since its opening in 1985, the quarry has produced 800 million tons of iron ore and excavated 1.4 billion tons of earth over an area of ​​8 million m2. It is so gigantic that it has become a national monument in Minnesota.

5. Diamond quarry Diavik

This Canadian diamond mine was opened in 2003 and produces up to 8 million carats of diamonds per year. In width it reaches a size of 7 kilometers. Also unusual is that it is located on the island of Lac de Grace in Canada's Northwest Territories.

4. Kimberley Diamond Quarry

This quarry is located in South Africa and belongs to the famous De Beers company. This is the largest quarry in the world, the development of which was carried out without the use of special equipment; in fact, it was completely dug by hand. Its diameter is about 1.6 kilometers, and its depth is more than 200 meters. Although it was closed back in 1914, it is still visited by crowds of tourists and is now in the process of being registered as a UNESCO World Heritage Site.

3. Kalgoorlie Super Quarry

Australia's largest open pit gold mine, the Kalgoorlie gold mine is 3.8 kilometers long, one and a half kilometers wide and approximately 600 meters deep, making it third in our list of the world's largest open pit mines.

2. Diamond mine Mir

Located in Eastern Siberia, this Russian diamond mine operated from 1957 to 2001 and produced up to 10 million carats of diamonds in its best years. It is now closed, but it is still the largest quarry in the world excavated without the use of explosives. Its diameter is 1.2 kilometers and its depth is 525 meters.

1. Bingham Canyon

Our winner, the largest and deepest open pit mine in the world, is located in the US state of Utah, southwest of Salt Lake City. This gigantic quarry is 4 kilometers wide and 1200 meters deep. It was opened in 1848 for the extraction of copper ore and since then copper, gold, silver and molybdenum have been mined there in large quantities.