FOSSIL COAL - solid fossil fuels, the product conversion plants. Main components: coalified organic matter, mineral impurities and moisture. Occurs usually in the form of layers of sedimentary rocks. Subdivided into brown coal, bituminous coal and anthracite. Coal resources are mainly used in power engineering, for metallurgical coke in the chemical industry. Main technical characteristics: ash content, moisture content, sulfur, volatile substances. World reserves of 3700 billion tons
Kuzbass is the main base of Russia for solid fuels. Technical analysis of coals (Russian coal).
All types of solid fuels combine two components: organic matter and mineral component, which primarily considered as ballast, but now increasingly considered a source of valuable minerals, including rare and trace elements. To assess the capabilities and modes of processing of fossil fuels used technical analysis, which allows to determine the direction of their use as an energy and chemical raw materials. Under the technical analysis refers to the definition of indicators provided by the technical requirements on the quality of coal.
In technical analysis methods are usually combined for determining in the coal and oil shale ash content, moisture content, sulfur and phosphorus, the yield of volatile matter, calorific value, sintering, and some other characteristics of quality and technological properties. Complete technical analysis is not always, it is often sufficient to reduce technical analysis, which consists in determining the moisture content, ash content and yield of volatile substances.
Due to the fact that water molecules may be associated with surface coal forces of different nature (absorption at the surface and in pores, hydrating polar groups of macromolecules, the occurrence of the crystalline mineral fraction) at different ways to release moisture from the coal, we obtain different values of its mass of dehydrated and, consequently, different values of humidity.
The mass of coal with moisture content, which he shipped to the consumer, is called the working masses of coal, and the moisture that is released from it by drying samples to constant weight at 105oC, called the general moisture of the working masses of coal.
The moisture content of fossil fuels is characterized by its moisture content. This value is expressed by the ratio of the mass released at the temperature of dehydration of water to the mass of the analyzed sample. Humidity is denoted by the letter W (Wasser).
Moisture reduces the useful coal mass transportation on its evaporation spent a lot of heat from fuel combustion, in addition, in the winter damp coal gets frozen.
The total moisture content varies depending on the degree of coalification fossil in the next row.
Turf> Brown coal> Anthracite> Fossil fuels.
In the fossil coals contain a significant amount (2-50%) minerals, which form the combustion ash. Bottom ash is formed after calcination of coal in an open crucible in a muffle furnace at a temperature of 850 ± 25 ° C.. Ashes to 95-97% consists of oxides of Al, Fe, Ca, Mg, Na, Si, K. The rest - the connection P, Mn, Ba, Ti, Sb, and rare and trace elements. Ash be designated by the letter Ad (Asche) and expressed in wt.%. The total moisture content and ash called ballast. The content of the actual mineral substances designated by the letter M. It is determined by physical and physico-chemical methods (eg, microscopic, fluoroscopic, radioisotope).
Volatile matter - vapor and gaseous products evolved during the decomposition of organic matter in the solid fossil fuel when heated under standard conditions. Devolatilization is denoted by V (volativ), access to the analytical sample Va, on the dry matter Vd, dry and ash-free Vdaf. This characteristic is important to assess the thermal stability of the structures that make up the organic mass of coal. Volatile matter on ignition was the basis for one of the classifications of coal marks.