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Abstract

Содержание

Relevance of the topic

Donbass is one of the major coal regions, which produces up to 80% of Ukraine's coal, which are used as energy fuel or as feedstock to produce coke. However, the Donetsk coal – is a high–ash (up to 40% in coal rank and file) organic compounds containing large amounts of pyritic sulfur (4–10%). Therefore, before using in production processes ordinary coal must pass a preliminary stage in the enrichment of mineral processing plants. After the coal preparation wastes are – coal sludge that accumulate in sumps or ilonakopitelyah not found wide practical application, and are a constant source of pollution.

Today, at 56 processing plants and landfill ilonakopitelyah Ministry of Coal Industry of Ukraine and Ukrkoks zaskladirovano 160 million tons of coal sludge off–balance sheet or the flotation tailings, which may be an additional source of energy [1]. Ash content of this rock in dumps in the range 30–70%, and the organic residue is 30–50%.

However, the technology used for extraction of off–balance sheet products of carbon–containing fuel component does not allow you to do it in full. They also can not be used in the manufacture of building and road materials, since the organic carbon content in the rock balance of more than 12% [2].

Therefore, given the shortage of energy resources is to conduct relevant to the extent of the coal industry targeted research to develop new technologies that reduce to a minimum loss of coal waste, as well as involvement in the use of heat power off–balance sheet products – waste and flotation coal cleaning, which will significantly reduce the material cost of producing one unit of output.

1. The purpose and objectives of the study

Objective:

To study the factors affecting the enrichment of coal slurryby gravity methods.

Objectives of work:

  1. The study of the effect of the concentration parameter table to theenrichment of coal slurry;
  2. study the influence of the characteristics of the source power to theenrichment of coal slurry;
  3. comparison of theoretical data and data derived from case studies of the process.

    2. Concentrating tables as a method of enrichment of sludge

    concentration on the table – the process of separation of mineral particles by density in a thin layer of water flowing down an inclined plane, which performs reciprocating motion in a horizontal plane perpendicular to the motion of water.

    concentration on the tables used for the separation of ores of tin, tungsten, rare, precious, ferrous metals and other minerals in the size of the material 0,01 – 3 mm. Concentrating tables can be used for enrichment and desulfurization of coal particle size to 13 mm, and in the process flotogravitatsii.

    Concentrating tables are one of the most ef fective devices, used for finishing rough con tsentratov obtained with the other dressing machine, to remove harmful contaminants and increase their content of minerals.

    The concentration tables can be easily and quickly change the degree of enrichment and produce concentrates of high concentration. The process of concentration on the table is easily adjustable, allows you to visually assess the nature and quality of incoming ore and emissions.

    concentration on the table is used not only as a basic process of enrichment, but also as an additional process in the flotation, jigging, magnetic separation, after the sluices, spiral separators, etc. Often

    technological indicators of enrichment obtained on jigs, spiral separators and gateways are compared with those obtained in the concentration tables as devices, providing more reliable high enrichment.

    3. Theoretical basis of mineral processing in the concentration tables

    Process of concentration was carried out prior to the fixed and mobile (round and tape) tables, which are now completely out of use because of their low productivity and replaced with swinging tables.

    swinging.

    Concentration tables consist of the following main components:

    1. deck (the plane) with attached strips on it (flute), feeding and distribution devices; on the deck there is a division of the material on the specific weights;
    2. supporting device and a mechanism to regulate cross–slope of the deck;
    3. reception facilities for discharged from the deck preparation products;
    4. drive mechanism, informing the deck continuous asymmetric reciprocation;
    5. gutter flushing Bodi, for uniform distribution of feed and transporting the liquid flow over the surface of the deck.

    Concentrating tables are mounted on the frame and supporting foundation.

    deck table has a rectangular or rhombic shape, made wood or aluminum alloy and covered with linoleum, rubber or fiberglass.

    Despite the fact that there are cataclysmic tables apply from the beginning of last century, the first description of the noun sion of the enrichment process in such tables appear only at the end of the last century in the works, and Robert Richards. [3–5]. The movement of mineral particles in the layer of water flowing down an inclined plane was investigated Rittingerom. Shparo [7–8] and Simons [9], but the theoretical basis of this process has been given for the first time Finkeem [9]. He believes that the velocity of a particle moving in an inclined jet of water on a flat solid surface is greater, the larger the diameter of the particle and the angle of the surface and the lower the proportion of particles. The same question was studied by VG Derkach [10], who pointed out some erroneous assumptions made in the paper by Finkeya. For example, Fink comes from the fact that the strength of the internal friction of a liquid is proportional to the normal mal pressure, ie, it applies the law of friction between solids to the internal friction of the fluid.

    The process of separation in terms of specific weights and particle size of staring vye has been experimentally studied by F. C. Dyer [11] for wooden and metal beads vyannyh of various sizes (Fig. 3a), which he subjected the cataclysmic movements in a glass vessel. As a result of vibration or shaking the bottom layer was composed of small metal balls (Fig. 3b). Above it is a layer of large metal metallic beads, the intervals between them filled with small wooden beads. Located just above a layer of fine wood, and even higher – a layer of large wooden beads. In the same paper FS Dyer pointed to the effective sion of the bundle of material of varying size, depending on the STI horizontal agitation or loosening. This phenomenon should also occur in cataclysmic tables, is confirmed by the distribution of grains in unit weight, cereals sion and shape of the surface of the deck as a fan. Lighter, large and elongated grains are located in the upper layers, while the heavier and smaller mineral grains occupy the bottom layer.

    4. Why is the concentration of interest tables

    Many researchers have noted that a properly set up concentration table is one of the most effective concentration apparatus capable of processing very wide range of particle size with a high recovery of the concentrate and the degree of enrichment [13].

    Concentration table is neither a high nor a compact car. However, thoughtful and reasonable space arrangement concentrator module type can significantly reduce the significance of these deficiencies.The main parameters affecting the separation process of the material, is the performance of the concentration table, the stroke length and stroke rate in December, the angles of the transverse and longitudinal slope, the amount of flushing water system narifleny.

    Such a set of control factors has none of the machines used to enrich the sludge. Due to the unique ability to manage the listed factors is achieved by the most high technological efficiency of the separation of various materials, including coal slurry ilonakopiteley.In addition is an effective desulfurization of coal – reducing pyritic sulfur in the 2 ... 3 times.

    Conclusion

    At a time when such huge reserves of coal slurries in ilonakopitelyah their permanent formation during extraction, transportation, and during the immediate enrichment, reprocessing of ground material is the priority issue of any processing plant.Removing the combustible matter of coal sludge requires considerable effort and expense, and loss of valuable components from waste has long lagged behind modern features and technology.

    Enrichment on the concentration table shows the highest extraction, this process requires a comprehensive approach to a wide choice of control parameters, and careful selection of these factors to the specific recyclable materials.Unfortunately, the enrichment in concentration tables can not find wide application in industry, due to the low performance of specific devices, but ways to improve in the future, not small, it needs to spend as much of the experimental trials and research. If the problem of poor performance will be resolved, concentration tables will replace a number of enrichment devices sludge exceeding them in qualitative terms.

    Scheme of the concentration of particles in the table (section view)

    Scheme of the concentration of particles in the table (view sverzu)

    List of sources

    1. Лобанов А.В., Иванова Е.В., Пейчев И.Д., Шифрин С.И., Черненко .А.К. Установка для сушки отходов флотации, извлекаемых из илонакопителей // Уголь Украины.–1996.–N12.–С. 32–34.
    2. Жаров Ю.Н., Новикова Н.Н., Клер В.Р. О стабильности состава отходов обогащения угля // Уголь.–1990.–N12.–С. 56 – 57.
    3. Richards, Robert H. Sorting before Sizing, Trans. Am. Ins. Win. Engrs., 1897. 27, 26, 76—106.
    4. Richards, Robert H. The Anaconda Round Table, thd Wttfley table and the Ten—Spigot Classifier. Min. Met. 1934. 15, 342–343.
    5. Richards, Robert H. The Wilfley Table. Trans. Am. Ins. Min. Engrs. 1907. Part 1 38, 556–580 1908. Part 11. 39, 303.
    6. Лященко П. В. Гравитационные методы обогащения ОНТИ, 1940
    7. Таггарт А. Ф. Справочник по обогащению полезных ископаемых, том III. Металлургиздат, 1952.
    8. Theodor Simons. Ore Dressing Principles and Practice, New York –London, 1924, p. 167.
    9. Финкей И. Научные основы мокрого обогащения, часть I. ОНТИ, 1932.
    10. Дер к а ч В. Г. Динамика водного потока (движущегося равномерно по наклонной плоскости) и анализ процесса разделения в этом потоке. «Горный журнал», 1938, № 7.
    11. Дайер Ф. С. О расслоении металлических и деревянных шариков по удельному весу и крупности. Engineering and Mining Journal, 1929, № 26.
    12. Берт Р.О. Технология гравитационного обогащения. – М.: Недра, 1990.–574 с.
    13. Великанов М. А. Движение наносов. Речиздат, 1948.