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Masters DonNTU

Dubik Maryna Sergeevna

Department:  Geotechnology and Management Speciality:   labor activity safety Theme of master's work: Cul-de-sac degasification in customary and emergency regimes Chief scientist:  “Labor protection and aerology” department associate professor Tchystuhin Viatcheslav Vladimirovych

ABSTRACT

CONTENTS

1.INTRODUCTION

      Mine degasification is the whole set of activities aimed at methane escaping from different sources extraction and recovery, its insulated removal to the surface, providing for methane physical and chemical binding before its movement into course [1].

      Degasification method selection is to be done grounding on gas balance structure, taking into account possible degasification efficiency factors in specific conditions. It is the source emitting the biggest methane amount to be degassed first.

2. THE AIM OF THE WORK

3. “MAKEYEV COAL” STATE ENTERPRISE“SEVERNAYA” MINE CHARACTERISTICS

     “Severnaya” mine was put into commission in 1971, rank of coal – coke OC, incidence angle – 6-9gr, the mine is dangerous in sudden emissions, maximum mining depth – 720m, coal bed preparation scheme - horizon-oriented, authoring system – combined, shift quantity - 3, mining coal bed m₃, 1,0-1,23m thickness. Methane distribution in the coal beds is not even, being determined by complex tectonic pattern, large tectonic faults.

     Coal bed m₃ characterized by high gas content, occur in active methane gas area. Expected coal bed gas content in western panel is measured to be 27 up to 36m³/t.s.b.m. at the depth of 550-1250m, and 36 up to 38m³ /t.s.b.m. at the depth of 1250-1450m.

4. CUL-DE-SAC DEGASIFICATION

     Degasification is maintained only during exceeding 3m³/minute methane emission into the course. When the course does not exceed 200m, barrier wells are drilled in the full length of the course. With the course longer, barrier wells are drilled in chambers on the both sides of course within thin and middle-thick coal beds. When a coal bed is 1,5m thick, there drilled a well at the distance of 1,5-2,5 m from each course with the well length 200mm and diameter 50-100mm.

     The distance accepted between stables during massif degasification by means of barrier wells is 15-20m shorter than the well length.

     During field coal bed preparation degassing wells are drilled in field courses in the direction to development drift area in the coal bed.

     Upper layer course degassing with flat thick coal bed layer working is maintained by means of wells drilled in courses out of stables.

     Development drift degasification characteristics are considered to be appropriately chosen when the methane emission decreased in 30-60% as a result of degassing. Every borehole mouth is sealed hermetically at the depth of 1,5m by a mechanical hermetizing seal while the boreholes are plugged into gas pipeline. The vacuum size must not be less than 50 mm of mercury column. Methane emission into the development drifts as a result of a borehole degassing can be reduced in 1,5-2 times. [2]

Figure 1. Coal massif degasification scheme during excavation.
Animation option: frame count=6, cycle index=7

     Applying mine degasification 3 main gas removing ways are possible:

• Emitted gas is removed by gas pipelines out of degassing area for further its air rarefaction at the areas with less gas content.
• Gas removed by means of exhausters goes via gas pipes on the surface and then released into the atmosphere.
• Removed gas with high methane content is utilized in the steam boiler fire chambers.

5. TECHNICAL EFFICIENCY OF DEGASIFICATION METHODS APPLICATION.

      The main efficient coal mine degasification methods’ criterion is the low gas content course decrease level, which is estimated by degassing efficiency factor.

К_д=(q'-q")/q'

Where q', q" – relative course gas content before and after methane emission source degasification respectively, m³/t; J', J"- absolute course gas content before and after degasification respectively, m³/minutes.

6. CONCLUSION

     Introduction of degasification at the “Makeyev coal” State Enterprise “Severnaya” mine will enable to reduce block gas content in 60-70%, remove longwall downtime because of gassing, increase longwall workload, development drift maintaining speed and to escalate labor safety in the areas of high gas content.

7. REFERENCE LIST

1. http://bse.sci-lib.com/article021257.html Значение слова «Дегазация шахт» в Большой Советской Энциклопедии.

2. Руководство по дигазации угольных шахт. – М.:Недра.1975, 189с.

3. Дегазация угольных пластов и вмещающих пород при проведении горных выработок. Временное руководство и типовой проект. -М.:ГОСГОРТЕХИЗДАТ. 1962г, с.38-40.

4. Дегазация выработанных пространств (Обзор). – М. 1976, 56с.

5. Патрушев М.А. и др."Совершенствование проветривания угольных шахт из опыта оазработки и внедрение эффективных схем проветривания"Донецк."Донбасс", 1976.- 126с.

6.  Руководство по проектированию вентиляции угольных шахт.- Киев.:"Основа",1994.-311с.

7. Ушаков К.З., Бурчаков А.С., Пучков Л.А.,Медведев И.И."Аэрология горных предприятий": Учебник для ВУЗов,-М.:Недра,1987.-421с.

8. Инструкция по расчету количества воздуха необходимого для проветривания действующих угольных шахт.М.:Недра,1975г.

9. Правила безопасности в угольных и сланцевых шахтах.- М.:Недра,1976г.

10. Шевяков Л. Д. /Разработка месторождений полезных ископаемых/. – М.: Углетехиздат, 1956г.

11. Задачник по подземной разработке угольных месторождений. Учебное пособие для ВУЗов/Сапицкий К. Ф., Дорохов Д. В., Зборщик М. П., Андрушко В. Ф. – 4-е издание. М.: Недра, 1981. – 311с.

12.Производственные процессы в очистных забоях угольных шахт /И.Ф. Ярембаш, В.Д. Мороз, И.С. Костюк, В.И. Пилюгин. – Донецк, РИА ДонГТУ, 1999. – 120 с.

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