Methods of carbon production

Carbon dioxide, methane, separately carbon, can be obtained chemically, that is, by intentional synthesis. However, this is not profitable.

Gas carbon and its solid modifications are easier and cheaper to produce in passing with coal.

About 2 billion tons of this mineral are extracted annually from the earth’s interior. Enough to provide the world with technical carbon.

As for diamonds, they are extracted from kimberlite pipes. These are vertical geological bodies, lava-cemented rock fragments.

It is in such diamonds that diamonds are found. Therefore, scientists suggest that the mineral is formed at depths of thousands of kilometers, in the same place as magma.

Deposits of graphite, in contrast, are horizontal, located at the surface.

Therefore, the extraction of the mineral is fairly simple and not costly. About 500,000 tons of graphite are extracted from the earth’s interior every year.

To get activated carbon, you have to heat the coal and treat it with a jet of water vapor.

Scientists even figured out how to recreate the proteins of the human body. Their basis is also carbon. Nitrogen and hydrogen are an amino group adjacent to it.

Oxygen is also needed. That is, the proteins are built on an amino acid. It is not at everyone’s hearing, but life is much more important than others.

Popular sulfuric, nitric, hydrochloric acids, for example, the body needs much less.

So, carbon is something worth paying for. We will find out how much the variation of prices for different goods from the 6th element is great.

For life, as it is easy to understand, carbon is priceless. As for other spheres of life, the price depends on the name of the product and its quality.

For diamonds, for example, they pay more if the stones do not contain third-party inclusions.

Airgel samples, for now, cost dozens of dollars for a few square centimeters. But, in the future, manufacturers promise to supply the material with rolls and reduce the price.

The carbon industry is considered the cause of the greenhouse effect. Enterprises are obliged to pay for emissions, in particular, CO2.

This is the main greenhouse gas and, at the same time, an indicator of air pollution.


Ways of using carbon

The use of an element and its derivatives is as extensive as their number. The carbon content in a person’s life is greater than it may seem.

Activated charcoal from the pharmacy is the 6th substance. A diamond in a ring from a jewelry store – it’s the same.

Graphite in pencils is also carbon, which is also necessary in nuclear reactors and contacts of electric machines.

Methane fuel is also on the list. Carbon dioxide is needed for the production of soda and can be dry ice, that is, a refrigerant.

Carbon dioxide serves as a preservative, filling vegetable stores, and more, is needed to produce carbonates.

The latter are used in construction, for example, limestone. And sodium carbonate comes in handy in soap making and glass production.

The carbon formula also corresponds to coke. He is useful metallurgists.

Coke serves as a reducing agent during the remelting of ore, extraction of metals from it.

Even ordinary carbon black is used as a fertilizer and a filler of rubbers.

Have not thought why car tires are black? It’s soot. It gives the rubber strength.

Soot, also, is included in shoe polish, printing inks, mascara. The popular name is not always used. Industrialists call soot carbon black.

The mass of carbon begins to be used in the field of nanotechnology. Made ultra-small transistors, and still tubes, which are 6-7 times stronger than steel.

Here you and the non-metal. By naught, scientists from China have joined the research. Of carbon pipes and graphene, they created an airgel.

It is a solid and durable material. It sounds weighty. But, in fact, the airgel is lighter than air.

In iron, carbon is added to produce so-called carbon steel. It is firmer than usual.

However, the mass fraction of the 6th element in the alloy should not exceed a couple, three percent. Otherwise, the properties began to decline.

Development of graphite fields

The development of graphite ores is carried out by open and underground methods. Among the three operated graphite deposits in Russia, two (Noginskoye, Botogolskoye) are being developed underground and one (Taiginskoye) is open.

The sizes of the quarry with open development at the Taiginskoye deposit of crystalline graphite have a length of about 3 km, a width of 200-250 m and a depth of more than 50 m. Losses in production are about 1%, dilution is negligible.

In the United States, the open mining of graphite ore is carried out using drilling and blasting operations with the subsequent transportation of ore by road to the concentrators.

The original system of development of graphite deposits is applied in the Republic of Madagascar. Openly processed are the upper, weathered graphite ores to a depth of 30-40 m. The work is carried out by terraces with the descent of ore to the lower horizons, from where the ore enters the concentrator.

The Noginsk graphite deposit, developed by the underground method (mine and mine), is characterized by a dilution rate of 2.8%, an ore humidity of 4.5%, a loss of 17.8%.

The Botogol deposit of high-quality, dense-grained graphite is developed by the tunnel method. The extraction is carried out by horizontal layers from the bottom upwards, with a bookmark of clearing space. Losses in production are about 8%.

Development of diamond fields

Indigenous diamond deposits, developed by the open method, or combined:

The upper horizons are open, and the deeper horizons are underground. In Russia, diamonds are mined only in the open way.

The open method of developing pipes is approximately the same in all fields. Consider it on the example of the pipe Fischi (South Africa).

The tube has an oval horizontal section and almost vertical contacts with the surrounding rocks. The zone of weathering of kimberlites extends to a depth of 60 m. A secondary phase, saponite, a swelling mineral that absorbs a large amount of water, occupies a significant amount in the composition of kimberlites. For this reason, the tube’s ore is hygroscopic and, when moistened, it quickly loses its strength properties, therefore special methods are used to isolate the surface of kimberlite from water, and when drilling wells dry dust collection is used.

The development of an open-pit tube began in 1966, and by 1990 the depth of the pit reached 423 m with an average annual decrease of 18-20 m. Over 97 million tons of kimberlite (about 5 million tons per year) were extracted and 55 million tons T of waste rock. The quarry area on the surface is 550,000 m2. This method of mining provided stable operation of the mine and good technical and economic indicators: a low overburden, a systematic transition to the underground method. An inclined trunk with a length of 1300 m at an angle of 12 ° from the surface to the quarry at a depth of 280 m was traversed in the enclosing rocks. It housed a conveyor for transportation of ore to the concentrating mill and an underground crushing plant, which made it possible to sharply reduce the number of working dump trucks.

Under the underground method, several systems of underground mining of diamond-bearing tubes are used.

The chamber system provides for the penetration of 8-meter chambers with a height of 12 m, separated by temporary 8-meter lobes, on each working horizon along the short axis of the tube. Kimberlite, taken out from the chambers and from the ends of the overlying horizon, under the influence of the weight of the collapsed rocks, falls on the bottom of the workhole, where it is loaded into trolleys and rolls back to the ore deposit located in the enclosing rocks, along which the kimberlite is fed to the main hauling horizon.

The method of slot development is used on the Premier tube (South Africa). As the tube was being developed on each working horizon, the main drifts ran parallel to the slit at intervals equal to half the distance from the gap to the boundaries of the ore body. At a depth of 270 m, the ore was discharged from the ore discharges into trolleys and transported along the haulage drifts. Further, the ore was fed into the crusher, crushed and transported to the surface. The most progressive method of development is a floor self-destruction; It provides high productivity (up to 5 million tons of kimberlite per year) at low cost and relatively small application of manual labor. Under this system, the destruction of kimberlite occurs under the influence of gravity, the number of working horizons and loading points is sharply reduced. The essence of the system consists in the fact that a scraper drift passes at a distance of 14 m from each other, from the gangway, oriented across the tube, at intervals of 3-5 m on both sides, square niches of 1-2 m in size are arranged in staggered order. The niches are rising up in the form of a funnel, rising to a height of 7.6 m above the level of the sole. The kimberlite blocks are then completely cut, and layers with a thickness of 18 m are produced in such a way that kimberlite breaks down and collapses into conical rebels. As a result, a compensating gap of 2.2 m in height is formed on the whole area of ​​the tube. After that, a massless kimberlite mass is left above the compensation space, which gradually under the influence of its own weight collapses onto the outlet funnels. As the kimberlite collapses, it is partially discharged to restore the compensation space, so the level of the kimberlite that is falling is constantly rising until it reaches the rocks of the overlying horizon. After that, the ore output continues at a certain rate, until an empty rock appears in the scrapers. The development of this horizon ends here, after which they start working on the underlying one.

Placer deposits with a depth of occurrence up to 40-45 m are processed by the open method. In the Republic of Sakha (Yakutia), production is carried out in the summer by bulldozer-hydraulic method. Sands fed by bulldozers are washed on a grid of a hydrocrocker with a cell size of 30-50 mm. The surface material is removed by the jet of water, and the sub-slurry pulp is transported through the pipes by a distance of 20, -2.5 km to the seasonal stationary concentrating mill. From a valley of long placers, diamonds are mined in a dredging way. Draghi move from the bottom up the river valley in transverse or longitudinal strokes. After the depletion of the main reserves, the dredges are re-promoted from the top down, with a shift in the moves relative to the primary ones.

Natural and technological types of diamond-bearing ores

The natural types of ores are diamondiferous kimberlites and diamondiferous lamproites, which are subdivided on the basis of the proportions of kimberlite itself and xenogeneic material and structural and texture features, on diamondiferous massive kimberlites, kimberlite breccias, tuff breccias, xenotubrubricchia, tuffs and tuffaceous sedimentary rocks.

There is no uniform technological classification of diamond-bearing ores. In the technical and economic typification of ores, two main technological types are distinguished: breccias with a clay content of less than 20% and breccias with a clay content of more than 20%. When processing these ores, both technological schemes and the cost of mining differ.

In general, as practice shows, the technological classification of ores is developed in each case independently during the exploration and subsequent exploitation of the deposit. Often, when the kimberlite body is composed of rocks of different phases of implantation, clearly differing in structural and texture features and the level of diamond content, the natural types of ores practically coincide with the technological ones. The main factor is the content of diamonds. Thus, in the Dalnyaya tube (Sakha-Yakutia) two natural types, kimberlite breccias and massive kimberlites, are distinguished here in terms of the level of diamond content by an order of magnitude and are also technological types. However, for example, during the operation of the Mir tube, six technological types of ores were distinguished, differing in nuances of structure and diamond content, whereas there were only two implant phases.

Technological types of diamond-bearing sands are isolated, based on their ripeness, clayiness, rinsing, etc.

Natural and technological types of graphite ores.

The graphite ores are typified by texture-structural features. Graphs are divided into explicitly and cryptocrystalline. Among the clearly crystalline isolates are denser-crystalline and scaly varieties. The dense graphite graphite is subdivided into coarse-grained graphite with an average crystal size of more than 50 μm and fine crystalline.

By the size of the scales, their diameter, flake graphites last for coarse-scaly (100-500 microns) and finely scaly (1-100 microns).

The cryptocrystalline graphites are composed of crystals having a value of less than 1 μm. Dense and finely dispersed or diffuse differences are distinguished. In the latter, the crystallites of graphite are scattered in the host rock. In dense differences, the graphite crystals form the bulk of the graphite rock. Only dense differences of cryptocrystalline graphite have an industrial significance.

On the level of carbon content, natural graphite consists of six commodity groups (%):
– crystalline lumpy – 92-95;
– crystalline large-scaly – 85-90;
– crystalline medium-scaly – 85-90;
– crystalline small-scaly – 80-90;
– crystalline powders with a size of up to 0.074 mm and graphite carbon content of 80-99.

Exploration of graphite deposits of other industrial types, having deposits of irregular shape or lenticular and rod-shaped, is also carried out by core drilling wells in combination with mine workings.

When assessing and exploring graphite deposits using drilling, the absence of selective core attrition is established, which is possible with an uneven distribution of graphite concentrations, in the form of enriched areas represented by a network of veins, lenses, nests, and the like. For this purpose, the graphite content in the drilling mud and slurry should be monitored. If necessary, pass checks with gross testing.

Industrial types of diamond and graphite deposits

The deposits of diamonds are divided into alluvial and indigenous, among which types and subtypes are distinguished, differing in terms of occurrence, the shape of ore bodies, concentrations, quality and stocks of diamonds, extraction and enrichment conditions.

Indigenous deposits of kimberlite-type diamonds are the main objects of operation throughout the world. Of these, about 80% of natural diamonds are mined. According to diamond stocks and sizes, they are divided into unique, large, medium and small. With the highest profitability, the upper horizons of the unique and large deposits emerging on the day surface are worked out. They contain the main reserves and forecasted diamond resources of individual diamondiferous kimberlite fields. Kimberlites are “volcanic vents” filled with breccias. Breccia consists of debris and xenoliths surrounding and deposited from above rocks, from debris of rocks taken from depths of 45-90 km and more.

The cement is a volcanic material, tuffs of alkaline-ultra-basic composition, the so-called kimberlites and lamproites. Kimberlite pipes are located on platforms, lamproite – in their folded frame. The time for the formation of tubes varies from Archaean to Cenozoic, and the age of diamonds, even the youngest, is about 2-3 billion years. The formation of the tubes is associated with a breakthrough upward through narrow channels at a high pressure, at a depth of more than 80 km, at a temperature of about 1000 alkaline-ultrabasic melts. Most of the well-studied kimberlite bodies have a complex structure; In the most simplified case, the structure of the tube involves two main varieties of rocks formed during two consecutive phases of introduction: breccia (1st stage) and massive “large-porphyry” kimberlite (2nd stage). In the structure of some kimberlite pipes, kimberlite dikes and veins associated with tubes were also identified. Blind bodies, formed by portions of kimberlite magma, did not reach the surface of the day. Deposits associated with dikes and veins of kimberlites are usually classified as small, less often average in diamond reserves. In many cases, a breakthrough has reached the paleo-surface, but many explosion tubes can be “blind” and have not yet been eroded by erosion .e. Lie somewhere in the depths. But even on the surface of the Earth there are places where there are enough pressures to form a diamond. These are the places of impact of meteorites, where the diamond is found not only in the Earth, but also in a number of meteorites themselves.

The velocity of the breakthrough magma probably could be very large, about 800 km / h, magma tore and carried up fragments of different composition. If they contained diamonds, the tube became diamond-bearing. Diamonds themselves are the most stable polymorphic modification of carbon in the deep zones of the Earth.

Lamproite type of diamond deposits was discovered relatively recently (1976) in Western Australia, where a large Argyll deposit is being exploited. In their structure, lamproite deposits are generally similar to kimberlite deposits. Judging by the Argyll exploration data, lamproite tubes somewhat wedge to a depth where they pass into dikes. The system of mining of these deposits and the technology of enrichment are the same as those at kimberlite objects.

Kimberlite-lamproite type is represented by a diamond deposit in the Arkhangelsk region, where the content of indicator minerals is significantly lower than in “classical” kimberlites, the overwhelming majority of diamonds are represented by the curved forms.

Ring impact structures ranging in size from the first to hundreds of kilometers are associated with super-powerful explosive processes, the source of which, according to different researchers, was either extraterrestrial (the fall of large celestial bodies) or endogenous in nature. In Russia, one deposit of this type was discovered – Popigajskoe on the eastern slope of the Anabar crystalline massif. In terms of ore reserves and the content of diamonds, the deposit exceeds hundreds of times the largest in kimberlites. However, diamonds in impact fields are encased in strong dense effusive rocks and are represented exclusively by technical varieties with admixture of lonsdaleite (a polymorphic modification of carbon, found in the form of plates alternating with graphite, but located perpendicular to its plane).

The metamorphogenic type is also represented by one deposit in Kazakhstan, where diamonds are found in biotite gneisses, biotite-quartz, garnet-pyroxene and pyroxene-carbonate rocks. According to the reserves and the content of diamonds, it is ten times higher than the largest high-diamond-bearing kimberlite pipes. Diamonds have an extremely small crystal size, and jewelry and high-quality technical varieties have not yet been found.

General characteristics of graphite

Graphite is a gray-black crystalline substance with a metallic luster, greasy to the touch, harder than paper.

The structure of graphite is layered, within the layer the atoms are bound by mixed ion-covalent bonds, and between the layers – by essentially metallic bonds.

The carbon atoms in graphite crystals are in sp2-hybridization. The angles between the directions of the bonds are 120 *. As a result, a grid is formed, consisting of regular hexagons.

When heated without air access, graphite does not undergo any change to 3700 * C. At this temperature, it is expelled without melting.

Crystals of graphite are, as a rule, thin plates.

Due to the low hardness and very perfect cleavage, graphite easily leaves a trace on paper, greasy to the touch. These properties of graphite are due to weak bonds between atomic layers. Strength characteristics of these bonds characterize the low specific heat of graphite and its high melting point. Due to this, graphite has an extremely high refractoriness. In addition, it conducts electricity and heat well, is resistant to many acids and other chemical reagents, mixes easily with other substances, has a low coefficient of friction, high lubricity and cover ability. All this led to a unique combination of important properties in one mineral. Therefore, graphite is widely used in industry.

The carbon content of the mineral aggregate and the structure of graphite are the main attributes that determine the quality. Graphite is often called a material, which, as a rule, is not only monocrystalline, but also monomineral. In general, the aggregate forms of graphite matter, graphite and graphite-bearing rocks and enrichment products are meant. In them, besides graphite, there are always impurities (silicates, quartz, pyrite, etc.). The properties of such graphite materials depend not only on the content of graphite carbon, but also on the size, shape and mutual ratios of graphite crystals. From texture-structural features of the material used. Therefore, in order to evaluate the properties of graphite materials, it is necessary to take into account both the features of the crystalline structure of graphite and the texture-structural features of their other constituents.