Mine Management, Legislation & General Safety
1. There has been considerable increase in mechanization of underground and opencast mines. Discuss the adequacy of the provisions of Coal Mines Regulations, 1957 in respect of qualifications and appointment of Safety Officers, First Class and Second Class Managers and Engineers in mines. Assume your own condition.
2. (i) What is meant by remote operation of coal face apparatus with pilot core protection? Discuss the associated voltage and current limits.
(ii) Describe a transwitch unit used belowground. What are (a) it’s special features and (b) the protective devices incorporated in it?
3. (a) What are bye-laws? How are they framed?
(b) Frame a set of bye-laws for use of continuous miner in a degree-l seam.
4. An explosion has occurred in a Degree – III mine in a depillaring district with stowing. How will you determine the cause of the explosion and its point of origin? How would you ascertain whether the explosion has occurred due to inflammable gas or coal dust or both? Assume your own conditions.
5. Write short notes on:
(i) Initial and periodical medical examination
(ii) Workmen’s Inspectors and their duties.
(iii) Medical attention in case of injury.
(iv) Disability allowance and compensation occupational disease
6. Describe the provisions of the Mines Act 1952 in respect of the following:
(i) Duties and responsibilities of owners, agents and managers.
(ii) Powers of inspectors of mines.
(iii) Annual leave with wages.
7. What are statutory provisions in respect of:
(i) Precautions after a fire has broken out.
(ii) Danger from underground inundation,
(iii) Splits and airways.
8. A thick coal seam that was developed in two sections was being extracted by opencast mining. There was active fire on coal face and a shovel was under operation at a distance of 50 metres on a lower coal bench of the same seam. Suddenly, water gas explosion occurred and the shovel was covered by hot ash/dust etc. causing instantaneous death of the shovel operator. Write an enquiry report of the accident suggesting out contravention, responsibilities and suggestions to prevent similar accidents in future. Assume you own conditions.
Winning & Working
1. Write short notes on the following:
(i) Hard roof Management,
(ii) Wide stall method,
(iii) Cable bolting,
(iv) Design of shaft pillar.
(v) Use of computers in Mine Planning & Design.
2. Describe in detail the methodology for the determination of physico-mechanical properties of the rock and its applications in design of roof supports.
3. What are the limitations of Surface Miners? Give a layout for a production of 6.0 million tons per year from an opencast mine with Surface Miners. Specify HEMM required and organization chart. Stripping ratio is 1 in 3. Assume you own conditions.
4. What are the different instruments available for the determination of ground movement in underground coal mines. Describe their applications in the prediction of roof falls.
5. Describe suitable method for working 4.0m thick coal seam, dipping at 1 in 8 and producing 2.0 million tonnes per year. Maximum depth is 500 m. State equipment details, organization and productivity. Assume suitable data wherever required.
6. Describe with neat sketches – Mechanised drivage of stone drift, dipping at 1 in 4 with a dimension of 4.2 m width and 3,4 height and 2.0 kilometers length. State cycle of operations, manpower, required and daily progress.
7. Describe with sketches – system of Mining with continuous miner technology and strata monitoring system. Thickness of coal seam is 4.5 m, dipping at 1 in 10. State machinery and manpower required, cycle of operations and production capacity.
8. Give a layout a quarry producing 10 million tonnes coal per year. Stripping ratio is 1:2. State selection of equipment and organization required. Assume your own conditions.
Mine Ventilation, Explosion, Fires & Inundation
1. Write short notes on the following:
(i) Self Rescuer and their use in underground.
(ii) Peripheral ventilation system.
(iii) Methane drainage.
(iv) Emergency organization in a coal mine.
(v) Tele Monitoring system.
2. What are the requisite properties of stone dust for use in underground coalmines? What objects do stone dust barriers serve in controlling explosion in coalmines? How far apart they should be placed? Give constructional details of such a barrier along with nature and quantity of dust used.
3. What is Ventilation Survey? How would you conduct such a survey in a coal mine? What precautions are necessary to secure accuracies?
4. What are the risks of installing and using booster and auxiliary fans in hot, humid and gassy coal mines? In case it is necessary to install one, what factors would you consider regarding the fan and its site of installation in relation to the existing ventilation and how would you proceed to do so?
5. What precautions will you take for an early detection of fire in a coal seam liable to spontaneous heating? What are the measures to control the Tire after it has been detected?
6. After explosion in a depillaring district of degree-Ill gassy mine being worked by bord and pillar method, describe what principal dangers are likely to be met with while exploring and restoring underground workings and how to overcome the same ? What measures can be taken to prevent such explosions?
7. What is the effect on the water gauge while the fan is running at a constant speed:
(i) If the main separation doors between intake and return are accidently left open.
(ii) If the evasee is completely closed.
(iii) If the air is coursed through two splits instead of one.
(iv) If there is considerable drop of temperature on surface.
(v) If there is a large fall of roof in main return, considerably, restricting the passage of air.
Give reason in each case.
8. A 1000 m long and 3×4 m cross-section drift is ventilated by a fan connected to two ducts of 400 mm and 300 mm diameter installed in parallel and extending to within 10m of the face. Calculate the delivery through each duct if the fan pressure is 3 K P assuming a coefficient of friction of 0.003 Ns2m-4 for the duct which may replace the two ducts without affecting the ventilation at the face? Neglect leakage.