Longwall Mining at Shallow Depth of Cover in India

By Tapan Kumar Mozumdar and Biswanath Pan

The method of mining under specific mining conditions was for the first time implemented in India with success. Similar conditions may arise in other coalfields, and the detailed study would surely guide the operators to overcome any problems likely to arise during actual mining operations.

• Language: English
• Publisher: Partridge Publishing India
• Release date: Mar 21, 2015
• ISBN: 9781482844429

Tapan Kumar Mozumdar

Both the authors are experienced and qualified experts in their own field of specialization, namely, safety and mining operations respectively. Enclosed CVs will justify the above statements.

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Copyright © 2015 by Tapan Kumar Mozumdar; Biswanath Pan.

ISBN:      Softcover      978-1-4828-4443-6

                eBook         978-1-4828-4442-9

All rights reserved. No part of this book may be used or reproduced by any means, graphic, electronic, or mechanical, including photocopying, recording, taping or by any information storage retrieval system without the written permission of the publisher except in the case of brief quotations embodied in critical articles and reviews.

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Contents

PREFACE

1.0 ABSTRACT

2.0 INTRODUCTION

3.0 REVIEW OF PAST EXPERIENCE

4.0 LONGWALL MINING, PRESENT EXPERIENCE IN SECL

4.1 GEO-TECHNICAL DETAILS & ASSESMENT OF SUPPORT CAPACITY:

4.2. CASE STUDY -1: PANEL P-1 & P-2 OF BALRAMPUR U/G MINE

4.3 RAJENDRA UNDERGROUND MINE: PANEL P-16

5.0 DISCUSSIONS

5.1 LOAD ON SUPPORTS AND SUPPORTS CAPACITY:

5.2 CONVERGENCE AND RATE OF ADVANCE:

5.3 INDUCED CAVING FROM SURFACE:

5.4 SUBSIDENCE AND ITS EFFECT ON LONGWALL OPERATION:

5.5 EFFICIENCY OF HYDRAULIC SYSTEM SUCCESS OF OPERATION OF LONGWALL:

5.6 STRATA CONTROL MONITORING:

6.0 MANAGEMENT OF MEN & MACHINES

6.1 OPERATIONAL PROBLEMS

6.2 PRODUCTIVITY & PROFITABILITY

7.0 RECOMMENDATIONS

8.0 FUTURE SCOPE OF APPLICATION

9.0 ACKNOWLEDGMENT

BIBLIOGRAPHY

S.N.   LIST OF FIGURES   Fig No.

1   Litholog at different positions along the travel of Longwall face in Panel-1 of Balarampur mine.   Fig-(BRP)1

2   Litholog along the travel of Longwall face in Panel-2)at Balarampur Mine.   Fig-(BRP)2

3   Litholog along the Panel- 16 of Rajendra underground Mine   Fig-(RP)3

4   Variation of Mean/Load density (After cut) against face advance)at Balarampur Mine.   Fig-(BRP)4

5   Variation of Mean/Load density (After cut) against face advance)at Balarampur Mine.   Fig-(BRP)5

6   Maximum cumulative convergence during periodic weightings)at Balarampur Mine.   Fig-(BRP)6

7   Convergence after different cuts in Balrampur Panel-1   Fig-(BRP)7

8   Curve showing subsidence profile along the Panel for different face advances)at Balarampur Mine.   Fig-(BRP)8

9   Subsidence profile across the Panel along 210m line from start of the Panel)at Balarampur Mine.   Fig-(BRP)9

10    Zone wise Mean Load Density in diff. Long wall Panels)at Balarampur Mine..   Fig-(BRP)10

11    Pressure Distribution between Front and Rear Legs at Diff. face advance in Long Wall Panel)at Balarampur Mine..   Fig-(BRP)11

12    Periodic Weighting at Face Advance -179m)at Balarampur Mine..   Fig-(BRP)12

13   Mean Load Density (MLD)along the Face P-16 when Max. Loading at Mid Zone)at Balarampur Mine..   Fig-(BRP)13

14   Interval of Weightings Before and After Blasting)at Balarampur Mine..   Fig-(BRP)14

15   Panel-Wise Breakdown Analysis)at Balarampur Mine..   Fig-(BRP)15

16   Delay Analysis of PSLW Panels)at Balarampur Mine..   Fig-(BRP)16 

S.N   LIST OF TABLES   Table No.

1   Minimum thickness of hard cover and weathered mass in panels worked at Jhanjra under Raniganj Coal Field (RCF).   Table No 1

2   Rock properties overlying E3 panel of Jhanjra Long wall face (Borehole E-3/1)   Table No 2:

3   Rock properties overlying E3 panel of Jhanjra Long wall face (Borehole E-3/1)-Contd.   Table No 3:

4   Lithological Information of Panel-P-1 &P-2 of Balarampur mine.   Table No (BRP) 4

5   Lithological Information of Panel-16 of Rajendra Underground Mine   Table No (RP) 5

6   Physico- mechanical Properties of different panels of Balarampur Mine.   Table No. (BRP) 6

7   BH - 1734 (105 M) Physico- mechanical Properties of panel- P-16 of Rajendra Underground Mine.   Table No. (RP) 7

8   Details of panel geometry for panels P-1 & P-2 of Balarampur Mine.   Table no. (BRP) 8

9   Technical details of supports of Balarampur Mine.   Table No. (BRP) 9

10   Technical details of Shearer Balarampur Mine.   Table No. (BRP) 10

11   .Details of Explosives Charge at Balarampur Mine.   Table No. (BRP) 11

12   .Trend of Loading of Supports before and after Blasting at Balarampur Mine.   Table No. (BRP)- 12

13   Interval Between The Periodic Weightingsat Balarampur Mine.   Table (BRP)- 13

14   Convergence At The Long Wall Face at Balarampur Mine.   Table No. (BRP) 14:

15   Leg Circuit Condition Monitoring-(Total Number Of Leg Circuits -206)at Balarampur Mine.   Table No. (BRP) 15.

16   Loading frequency & MLD during periodic weighting at Balarampur Mine.   Table No. (BRP) 16

17   Frequency Of Periodic Weighting at Balarampur Mine.   Table No. (BRP) 17

18   Convergence During Periodic Weighting In Panel P-2 at Balarampur Mine.   Table No. (BRP) 18

19   Average cumulative convergence in mm/mt of the face advance at Balarampur Mine.   Table No. (BRP) 19

20   Max convergence in mm/ mt during individual cut at Balarampur Mine.   Table No. (BRP) 20:

21   Loading frequency and MMLD during periodic weighting at Rajendra Mine.   Table (RP) 21

22   Effect of Blasting on Face conv. During periodic weighting at Rajendra Mine.   Table No. (RP)22

23   Frequency of weighting at different distance of blasting at Rajendra Mine.   Table No. (RP) 23

24   Effect of Induced Caving on periodic weighting at Rajendra Mine.   Table No. (RP) 24

25   Cumulative convergence in mm/mt of face advance at Rajendra Mine.   Table No. (RP) 25

26   Cumulative Convergence in mm/hr. at Rajendra Mine.   Table No. (RP) 26

27   Effect of Induced Caving on Subsidence at Rajendra Mine.   Table No. (RP) 27

28   Management