It is difficult to imagine something more indispensablefor humanity, than coal. Its application is so multifunctional that sometimes it's just amazing. At such moments, doubt involuntarily creeps in, and in the head sounds quite a logical question: "What? Is it all coal ?! ". Everyone has got used to consider coal as only combustible material, but, in fact, the range of its application is so wide that it seems simply incredible.
The appearance of coal on Earth refers tothe distant Paleozoic era, when the planet was still in the development stage and had a species completely alien to us. The formation of coal beds began about 360,000,000 years ago. This was mainly in the bottom sediments of prehistoric water bodies, where organic materials accumulated for millions of years.
Проще говоря, уголь - это останки тел гигантских animals, tree trunks and other living organisms, submerged on the bottom, decaying and pressing under the water column. The process of reservoir formation is quite long, and for the formation of a coal seam it takes at least 40,000,000 years.
People have long understood how importantindispensable for coal, properties and the application of it could be assessed and adapted with such a scope relatively recently. Large-scale development of coal deposits began only in the XVI-XVII centuries. in England, and the extracted material was used mainly for smelting pig iron, which is necessary for making guns. But its production by today's standards was so insignificant that it can not be called industrial.
Large-scale mining began only closer to themid-nineteenth century, when the development of industrialization has become simply necessary for coal. Its application, however, at that time was limited solely to burning. Now hundreds of thousands of mines are working all over the world, a day extracting more than a few years in the XIX century.
Deposits of coal seams can reach depths of several kilometers, leaving into the earth's thickness, but not always and not everywhere, because it is heterogeneous in content and appearance.
There are 3 main types of this fossil: anthracite, brown coal, as well as peat, which is very remotely resembles coal.
Anthracite is the oldest education on the planetof this kind, the average age of this species is 280,000,000 years. It is very hard, has a high density, and the carbon content in it is 96-98%.
The hardness and density of brown coal is relativelyis small in the same way as the carbon content in it. It has a unstable, loose structure and is also oversaturated with water, the content of which can reach up to 20%.
Peat is also referred to as a coal species, but not yet formed, so it has nothing to do with coal.
Now it is difficult to imagine anotherthe material is more useful and practical than coal, the basic properties and application of which deserve the highest evaluation. Thanks to the substances contained in it and compounds, it has become simply irreplaceable in all spheres of modern life.
The composition of hard coal looks like this:
the average content of volatile substances reaches 35-40%;
the average ash content does not exceed 15-18%;
the average moisture content fluctuates between 12-15%;
the average calorie content is equal to 5500-7000 kcal / kg.
All these components make coal,the use and use of which is so multifunctional. The volatile substances contained in the coal provide a rapid ignition with the subsequent achievement of high temperatures. The moisture content simplifies the processing of coal, caloric content makes its use indispensable in pharmaceutics and cosmetology, ash itself is a valuable mineral material.
Various applications of minerals. Coal was originally only a source of heat, then energy (turning water into steam), now in this sense, the possibilities of coal are simply unlimited.
Thermal energy from coal combustion is convertedin the electric, from it they make coke and chemical products and extract liquid fuel. Coal is the only rock in which impurities contain rare metals such as germanium and gallium. It produces coke oven gas, which is then processed into benzene, from which the cumarone resin is extracted, which is used to make all kinds of paints, varnishes, linoleum and rubber. Aromatic hydrocarbons, phenols and pyridine bases are obtained from coal. When processing, coal is used in the production of vanadium, graphite, sulfur, molybdenum, zinc, lead and many other valuable and irreplaceable products.
