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Dachkovskaya Victoria

Dachkovskaya Victoria

Institute of Mining and Geology

Safety of labor activity

Theme of master's work:

The choice and substantiation of technological solutions for reduction of negative impact of dust and gas formation, measures on improving safety and working conditions of miners in Kirova mine

Scientific adviser: Nikolaev Evgeniy

Materials on the theme of master's work: |About myself|
The choice and substantiation of technological solutions for reduction of negative impact of dust and gas formation, measures on improving safety and working conditions of miners in Kirova mine.

Substantiation of the topic and its actuality

Constant deepening of mining in Donbass mines leads to more frequent and more powerful gas dynamic phenomena, the number of seams which are likely to outburst suddenly and to produce dust as well. The rate of mining work slows down because of these factors, labour intensity decreases and occupational diseases happen more often.
Work objective is to choose rationally the parameters for the scheme which aims at dust and gas reduction in Kirova mine.

Tasks

To do the analysis of the dust regime in coal mines, the normative base and methods of dust and burst safety control of mine workings.
To develop an effective method of dust reduction which can be used in Kirova mine.

General information on the mine

Kirova mine is situated on the territory of gornyatsky district of the town of Makeyevka Donetsk region. Joint venture "Kirov mine" was opened in 1996 on the base of the mine office of the same name, which included two mines : mine №1 named after S.M. Kirov and Kirovskaya-Zapadnaya mine . Mine №1. was opened in 1947 with capacity of 90 000 tons a year. Kirovskaya-Zapadnaya mine was opened in 1948 with capacity of 100 000 tons a year.
The capacity of the mine on 1.01.2007 is 600 000 tons a year. It develops 2 seams l1 and h10в. The category of the mine according to methane – dangerous of sudden outbursts. As far as coal dust explosions are concerned seam l1 is considered to be a hazardous one, seam h10в is non-hazardous. Seam l1 belongs to hazardous from the depth of 320 m., and seam h10в – from the depth of 230 m.
The field of the former mine №1 named after S.M.Kirov is cut open with two vertical shafts (cage shaft over the area l81 , which is not in use at the moment) and ventilation one on the horizon of 475 m, which is inclined by an additional shaft towards seam l81 (which is not in use either). For fresh air stream there is a air supply borehole d=3.2m on the horizonн of 475 m. The ventilation shaft of the horizon of 475 m and air supply borehole are used for developing seam l1 and in the future they will be used for mining development of seams of "Kamenskaya" series.The field of the former mine "Kirovskaya – Zapadnaya" is cut open with two centrally located vertical shafts (cage one and skip one), pit-hole №"0" and two inclined shafts over the area h10в (inclined air supply shaft over the area of h10в and inclined conveyer shaft over seam h10в.).
Coal commercial reserves of the mine on 1.01.2006 года are 20342 000tons.
Gas content of the mine: absolute – 37,72 m /min; relative – 40,0m3/min.[1]

Characteristics of the coal seams.

Seam l1 – of a complex structure mainly consists of 5patches. The stratum is clay slate or coal-clay one, width 0.02 – 0.05m. The coal is semibright, mangy, thin-bended, medium-hard coal with hackly structure and prismatic jointing.
It can be characterized by the following parameters: S=1,5%; W=1.8%; V=23,5%; Aс=32.,0–36,0%.
Natural gas content 21 m3/t.d.a.m., it is coal dust explosion hazardous, spontaneous firing hazardous. The seam is sudden coal and gas outburst hazardous from the depth of 320 m.
Adjacent strata: hanging wall – sandy, clay slate; footwall – sandy clay.
Seam h10в – of a complex structure. It consists of two coal patches, which are divided with stratum of gritty clay with width of 0.04–0.09 m. The coal is black, semibright, mangy, in the hanging wall layer of laminated structure. Hardness – 1,7 width 0.94–1.07m. Resistance of pure coal to cutting –120 kg/sm, with stratum and dirt 140 kg/sm. S=2.7–3.8%; W=2.0%; V=9.8%–11%; A =20–26%.
The seam is not coal dust explosion hazardous, it is sudden coal and gas outburst hazardous from the depth of 230 m, natural gas content is 45–25 m3/t.d.a.m., it is not spontaneous firing hazardous.
Adjacent strata : hanging wall – clay slate; footwall – sandy clay, sandstone.
Seam l4 – of a simple structure. The coal is semibright, banded, mangy, it has single sulphur kidneys. The seam is sudden coal and gas outburst hazardous from the depth of 320 m. Natural gas content is 20 m3/t, it is not of a blower character, coal dust explosion hazardous, it is not spontaneous firing hazardous. Maximum depth of the workings is 500m.
The seam can be characterized by the following parameters: S=1,4%; W=1,2%; V=21,7%; A=9,4%
Adjacent strata: hanging wall – sandstone, sand slate; footwall – sand slate, sandstone.
Seam k5 – is 25m lower than seam k5’, It is of continuous formation. The width is 0,45–1,0m, more often 0,6–0,7m. The seam of a simple structure. Most of the seam consists of sand slate, sometimes of sandstone and clay slate. The width of clay slate is 3,0–7,2m. Most of the footwall consists of sandstone with width of 4–26m. The maximum depth of the workings is 575m.
Seam k42Н – is of a complex structure. It consists of two coal patches which are divided with stratum of sand slate. The coal is black, semibright, bended, it has hackly fracture and sulphur kidneys. The seam can be characterized by the following parameters : S=3,5%; W=2,0%; V=17,5%; A =24,8% The seam is coal dust explosion hazardous, sudden coal and gas outburst hazardous from the depth of 320 m, natural gas content is 15,0 m3/t, it is not spontaneous firing hazardous .
Adjacent strata: hanging wall – sand slate, sandstone; footwall – sandstone. Maximum depth of the workings is 575m. [3,4]
The main dust sources at the site are :
  1. Coal extraction with coal cutter–loader.
  2. Coal extraction by a cleanout machine in holes.
  3. Coal transportation by drift belt.
  4. Goaf pack building.
  5. Sloping blast-holes.
  6. Cal unloading from one drift belt to the other one.
  7. Rock blasting in the belt road.
  8. Ground breaking by a cleanout machine in the airway.
For dust control the following methods are used:
  1. Coal prewetting in the solid.
  2. Dust elimination of the air flow.
  3. Spraying of collar of the blast-hole.
  4. Dust control while having blasting workings.
  5. Spraying while coal unloading from one drift belt to the other one.
  6. Spraying on the coal cutter-loader.
  7. Spraying of loosened coal in the holes.
  8. Use of personal protective equipment. [2,10]

Coal prewetting in the solid

Coal prewetting means filling the solid with water until its destruction (it is most common coal deposits development). It is done via the wells which are drilled over the seam in parallel or perpendicularly with the plate of the working face, development faces, as a rule in the plate of the face. There is a low pressure (from the water main) and a high pressure (from the pump) prewetting.

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The main parameters on which the effectiveness of this method depend are pressure and water rate , the distance between the wells, the depth of the hermetization of the wells, water consumption and the time between water infusion and coal extraction. The parameter values depend on the coal seam characteristics. Air dust content is reduced while developing wetted solids because of total wetness content of the destructing material is decreased, it is weakened as a result of physical and chemical and hydrodynamic processes of the contact between water and the solid and dust wetting, which is present in the solid before its destruction. The effectiveness of prewetting is 60-80%. Sometimes in order to increase it water solutions of moistures, electrolytes, etc. are used. Prewetting has economical effect by means of the solid weakening (by 20-40%), gas content reduction of the faces (at 10-20%) and firing hazard reduction (while having antipyrogen delivery. [7]

Literature

  1. Правила технической эксплуатации угольных и сланцевых шахт (Недра,1976 г.)
  2. Положение о порядке расследования и ведения учета несчастных случаев, профессиональных заболеваний и аварий на производстве и непроизводственного характера. – Донецк, 2001. – 77 с.
  3. Методические указания к деловой игре «Расследование несчастных случаев и аварий в угольных шахтах» (для студентов горных специальностей) Сост.: Ю.Ф. Булгаков, В.В. Яйло, А.Л. Кавера – Донецк: ДонНТУ, 2002. 31с.
  4. Руководство по борьбе с пылью в угольных шахтах – 1979 год.
  5. «Инструкция по предупреждению и локализации взрывов угольной пыли способами, основанными на применении воды» – 2003 год.
  6. Указывая по проектированию трубопроводов в подземных выработках угольных шахт – 1971 год.
  7. Правила безопасности в угольных и сланцевых шахтах.
  8. Руководство по проектированию вентиляции угольных шахт (под ред. Г.П. Яковенко). Киев, «Основа», 1994, 312с.
  9. Сборник инструкций и других нормативных документов по технике безопасности в угольной промышленности А.О. Бабокин, Москва, Недра,1978,743 с.
  10. Основы охраны труда М.Н.Гандзюк, Киев,383с

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