I was a major in geological engineering, in the practice of mineral petrology, the teacher asked, "the mineral composition of coal?" Is a mineral petrology, coal chemistry is not in, please master, senior students. Thank you
One, the carbon in coal is generally believed that coal is composed of large aromatic rings with a fat side chain and condensed ring composed of. These fused rings are made of carbon. Therefore, the carbon element is the most important element of organic polymer. At the same time, there is a small amount of inorganic carbon in coal, mainly from carbonate minerals, such as limestone and calcite.
Oxygen in coalOxygen is the third important component of coal. It exists in two states: organic and inorganic. Organic oxygen is mainly found in oxygen-containing functional groups, such as carboxyl (--COOH), hydroxyl (--OH) and methoxy (--OCH3) and so on. Inorganic oxygen is mainly found in water, silicate, carbonate, sulfate and oxide. The organic oxygen in coal decreases with the deepening of coal, and tends to disappear. When the content of dry ash free carbon is less than 70%, the oxygen content of lignite can reach more than 20%. When the carbon content of bituminous coal is near 85%, the oxygen content is almost less than 10%. When the carbon content of anthracite is above 92%, the oxygen content is reduced to less than 5%.
Hydrogen in coalHydrogen is the second important component of coal. In addition to organic hydrogen, there is also a small amount of inorganic hydrogen in coal minerals. It is mainly present in the crystallization of mineral water, such as kaolin (Al203 / 2Si02, 2H2O), gypsum (CaS04 / 2H20) and other crystalline water. In the whole process of coal metamorphism, with the deepening of coalification degree, the content of hydrogen decreases gradually, and the coal with low coalification degree has high hydrogen content. The general rule is that the hydrogen content decreases with the increase of carbon content. Especially in the anthracite phase is particularly evident. When the carbon content increases from 92% to 98%, the hydrogen content decreases from 2.1% to less than 1%. When the carbon content is between 80 and 86%, the hydrogen content is the highest. In the coal gas and coal, hydrogen content can be as high as 6.5%. When the carbon content is 65 ~ 80%, the content of hydrogen is less than 6%. However, the trend is that the hydrogen content decreases with the increase of carbon content.
The composition of coal is mainly composed of organic matter, which is mainly composed of carbon, hydrogen, oxygen, nitrogen and other elements. There are ten kinds of elements in coal, but the elements of coal are usually composed of five elements, namely carbon, hydrogen, oxygen, nitrogen and sulfur. In coal, the content is very small, a large variety of other elements, generally not as the composition of the elements of coal, but only as an element or trace elements in coal.
