Mine Management, Legislation & General Safety
1. You are the manager of a mine which uses continuous miners and shuttle cars for extraction of pillars at a depth of about 400 m. The seam dips at 1 in 5 and has a thickness of 4.0 m. Immediate roof is hard sandstone.
(a) List what you would consider the five major risks in such an operation which are needed to be managed.
(b) List and describe control measures for the three highest ranked risks.
(c) Who would you involve in the risk assessment process.
2. A 6.0 m thick coal seam was being extracted by opencast method deploying HEMMs. The overburden consisted of a 25 m thick cover of soft soil followed by shale and sandstone. A sudden failure of benches for length of about 400 m and part of a dump lying near the edge of the query occurred buying two shovels and four dumpers resulting in death of six operators and an overman. Write an enquiry report of the accident bringing out contraventions, responsibilities and suggestion to prevent similar accidents in future. Assume your own conditions.
3. In the present day context of heavy mechanization and outsourcing, give you views on adequacy of the provisions of Mines Vocational Training Rules. Suggest improvements and steps to be taken to make vocational training effective.
4. Design and emergency plan of a belowground mine with dangers from spontaneous heating and inflammable gas. How can you make it effective?
5. Describe different type of man-riding systems available and their limitations. Discuss safety provisions of each system.
6. What are notified diseases? Which of other diseases you would like to be included in notified diseases. Discuss the system of “Occupational Health Surveillance” in your organization, its short coming and suggest improvement.
7. Discuss the following:-
(i) Information Technology in mines safety.
(ii) Development of communication systems in mines.
(iii) Use of site mixed slurry explosives with special reference to safety,
(iv) Electronic detonators.
8. Write detailed note on the following as per IER, 1956.
a. Overhead lines in opencast mines
b. Precautions to be taken in use of electricity in degree III gassy mines.
Winning & Working
1. An underground mine having a seam of 4 meter thick and dipping at 1 in 20 with hard floor and moderate roof is having standing pillars in already developed panels. The panels are to be depillared by continuous miner for a production of 1500 tonnes/day. Give the layout of the panel and describe with backup matching transport system along with the major machinery to be deployed and support system to be adopted. Assure your own conditions. Also give the minimum manpower structure/day.
2. A development panel of 6 headings is approaching within 45 m of railway acquired land. What are the statutory requirements and precautions to be taken for development within 45 meters and also beneath railway acquired land? Assume your own conditions.
3. You are the manager of an underground mine having a production capacity of 1200 T.P.D. and presently producing 800 Tonnes/day from 3 bord and pillar districts at an overall O.M.S. of 0.8 tonnes, and incurring a loss of about Rs. 400/tonne.
Propose a suitable approach and suggest remedial measures to be taken to make the mine economically viable. Coal is of grade ‘B’. Assume your own condition.
4. Give a layout of opencast mine having an annual capacity of 10 million tonnes and 45 million Cu.m. of over burden removal, shovel dumper and dragline combination. The coal seams are 20 m thick and 10 m thick with 25 meters parting and dipping at 1 in 20 gradient and lying at a depth of 50 meters to 160 meters. Indicate the number and capacity of major earth moving machines and minimum statutory manpower required per day.
5. In an underground mine it is proposed to depillar a panel with L.H.Ds with a production of 400 T.P.D. Assume your own conditions and give the panel layout, number and type of equipment, support plan and daily manpower required. Describe your propose method of working.
6. One 3.5 meter thick degree- ll gassy seam with a gradient of 1 in 15 lying at a depth of 180 meters having massive sandstone roof and strong floor is to be worked by longwall retreating with caving method for an output of 2500 tonnes/day. Give layout for the longwall panel indicating equipment details, powered roof supports, cycle of operation, face organization, ventilation layout, total investment, productivity and expected cost/tonne.
7. Write short notes on any three:
(i) Shortwall mining, i.e. extraction of developed pillars by longwall
(ii) Blasting gallery method.
(iii) Inpit crushing in opencast mine,
(iv) Nonel system of blasting in opencast mine.
8. You are the manager of an underground mine and the mine is being developed on board and pillar method with depth of cover ranging between 45 m to 200 m. The immediate roof is shaly strata with particular problems of strata in junction and dip-rise galleries.
Answer the following:
(i) Suggest measures for safe/improved strata control.
(ii) Give a suitable support system.
Mine Ventilation, Explosion, Fires & Inundation
1. Write short notes on:
(a) Coal bed methane
(b) Use of explosive in Degree III gassy mine.
(c) Automatic fire protection system in mine
(d) Noise levels and noise induced hearing loss among mine workers.
2. (a) What are the statutory provisions against dangers of spontaneous heating?
What additional precautions would you take for early detection of fire in a highly gassy seam liable to spontaneous heating?
(b) A district sealed off due to fire is proposed to be reopened. What are the various factors to be considered before deciding to reopen? Describe in brief the dangers associated and precautions to be taken during recovery work.
3. What is the advantage of self-contained self rescuer over filter type self rescuer? Discuss the salient points for use, care and maintenance of self-contained self rescuer in a mine. How will you access the requirement of self-contained self-rescuer in a mine?
4. (a) What are the statutory provisions for ventilation standards of a mine?
(b) A large mechanized mine is being planned for production of 2000 TPD through a pair of incline and an air shaft. Seam is Degree-Ill gassy. Explain in detail the ventilation requirement, capacity of main mech ventilator and related infrastructure.
Assume your own conditions.
5. (i) Discuss the following:
(a) Local methane detector
(b) Coal mine methane and abandoned mine methane.
(c) Precautions against airborne dust.
(ii) A fan delivering 8000 m3/min at 40 mm w.g. is run by a 3.3 kv AC motor drawing 40 amps at a power factor of 0.85 lagging. Calculate the overall efficiency of the fan. Assuming power cost to be Rs. 4/KWH, Calculate the annual cost.
6. Describe the ventilation arrangements in a long coal heading being driven with a road header in a gassy mine of Illrd Degree. Suggest a suitable methane monitoring system.
7. (i) What do you understand by natural ventilating pressure? What is its effect on the mechanical ventilation?
(ii) What do you understand by explosibility of coal dust? Suggest the preventive actions to control harmful coal dust from explosion as well as health hazard.
8. (i) What are the statutory provisions of precautions against danger of inundation from underground?
(ii) What precaution would you suggest for developing a seam while approaching the stowed goaf of underlying seam lying at a parting of 6 m?