Course Objectives

• To understand the concept of underground coal mining
• To understand the concept of bord and pillar mining .
• To understand the concept of pillar extraction.
• To understand the concept of longwall mining.
• To understand the concept of roof support.
• To understand the concept of thick seam mining.

Learning Outcomes

• To understand development of pillar , extraction of pillar and Longwall mining method.
• To understand panel system of mining and mechanized extraction of longwall panel .
•   To understand the concept of underground coal mining and all other operations that are concerned with the underground coal mining.

Course Syllabus

UNDERGROUND COAL MINING

MODULE I

Bord and Pillar Mining:

Choice of methods of mining coal seams; factors affecting choice of mining methods. General principles of Bord and Pillar (B&P) development, different schemes of development and associated merits/demerits; Design of B&P workings, statutory provisions related to B&P workings, Semi-mechanized and mechanized schemes of B&P development; Mechanized face loading. Conditions suitable for mechanical loaders and continuous miners.

Pillar extraction:

Preparatory arrangement for depillaring operation, statutory provisions on depillaring; principles of designing pillar extraction, factors affecting choice of pillar extraction; partial and full extraction; depillaring with caving and stowing; mechanization in depillaring operation. Local and main fall, indications of roof weighting, measures to bring down roof at regular interval; air blast and measures to minimize its effects; precautions during depillaring operation against fire and inundation; multi-section and contiguous workings. Extraction of pillars in seams prone to bumps.

MODULE II

Longwall Mining:

Factors affecting longwall mining, longwall face layouts, advancing and retreating faces, single versus double unit longwall faces, orientation of longwall faces; single versus multiple heading gate roads, factors affecting length and width of longwall panel. Extraction of Longwall panel, working with shearer and plough, support system of longwall face and gate roads, monolithic packing in longwall advancing gate roads; case studies of longwall faces in India.

Thick seam mining:

Board and pillar and long wall mining in multi section, multi slice method, incline slicing, horizontal slicing and cross slicing in ascending and descending order, under winning method, sub level caving, integral caving – horizontal slicing with caving / stowing – blasting gallery. Method – sub level caving with mechanizes long wall. horizon mining – merit – demerit – application & limitation. Modern method – applicable condition of plough, method of working by plough, unidirectional ploughing method, bi – directional ploughing method over passing hydraulic mining merit & demerit applicable condition of underground gasification of coal merit, demerit of gasification of coal, method of extraction of gasification & contiguous seam.

MODULE III

Roof Supports:

Timber props and cogs; friction/hydraulic props and chocks; other steel supports; types of roof bolts; function, applicability and advantage of roof bolting and cable bolting; powered supports; systematic support rules; supporting scheme of development gallery, B&P and L/W faces, depillaring district; withdrawal of support. Conditions requiring stowing in mines; types of stowing; suitable materials for hydraulic stowing; stowing plant and stowing range; hydraulic gradient and hydraulic profile.

Reference book:

1. Elements of mining technology Vol 1 by D J Deshmukh , Denett publisher Nagpur.

2. Principle and practice of modern coal mining by RD Singh , New age international publisher.

Session Plan

Session 1

LECTURE:

Choice of methods of mining coal seams; factors affecting choice of mining methods.

WEB LINK:

Session 2

LECTURE:

General principles of Bord and Pillar (B&P) development, different schemes of development and associated merits/demerits.

WEB LINK:

Session 3

LECTURE:

Design of B&P workings, statutory provisions related to B&P workings.

WEB LINK:

Session 4

LECTURE:

Semi-mechanized and mechanized schemes of B&P development; Mechanized face loading.

WEB LINK:

Session 5

LECTURE:

Conditions suitable for mechanical loaders and continuous miners.

WEB LINK:

Session 6

LECTURE:

Preparatory arrangement for depillaring operation.

WEB LINK:

Session 7

LECTURE:

statutory provisions on depillaring

WEB LINK:

Session 8

LECTURE:

principles of designing pillar extraction, factors affecting choice of pillar extraction

WEB LINK:

Session 9

LECTURE:

partial and full extraction; depillaring with caving and stowing.

WEB LINK:

Session 10

LECTURE:

mechanization in depillaring operation.

WEB LINK:

Session 11

LECTURE:

Local and main fall, indications of roof weighting, measures to bring down roof at regular interval; air blast and measures to minimize its effects.

WEB LINK:

Session 12

LECTURE:

precautions during depillaring operation against fire and inundation; multi-section and contiguous working.

WEB LINK:

Session 13

LECTURE:

Extraction of pillars in seams prone to bump

WEB LINK:

Session 14

LECTURE:

Factors affecting longwall mining, longwall face layouts, advancing and retreating faces, single versus double unit longwall faces, orientation of longwall faces.

WEB LINK:

Session 15

LECTURE:

single versus multiple heading gate roads, factors affecting length and width of longwall panel.

WEB LINK:

Session 16

LECTURE:

Extraction of Longwall panel, working with shearer and plough, support system of longwall face and gate roads.

WEB LINK:

Session 17

LECTURE:

monolithic packing in longwall advancing gate roads; case studies of longwall faces in India.

WEB LINK:

Session 18

LECTURE:

Board and pillar and long wall mining in multi section, multi slice method, incline slicing, horizontal slicing and cross slicing in ascending and descending order.

WEB LINK:

Session 19

LECTURE:

sub level caving, integral caving – horizontal slicing with caving / stowing – blasting gallery.

WEB LINK:

Session 20

LECTURE:

Method – sub level caving with mechanizes long wall. horizon mining – merit – demerit – application & limitation.

WEB LINK:

Session 21

LECTURE:

Modern method – applicable condition of plough, method of working by plough, unidirectional ploughing method, bi – directional ploughing method over passing hydraulic mining merit & demerit applicable condition of underground gasification of coal merit, demerit of gasification of coal.

WEB LINK:

Session 22

LECTURE:

method of extraction of gasification & contiguous seam.

WEB LINK:

Session 23

LECTURE:

Timber props and cogs; friction/hydraulic props and chocks; other steel supports; types of roof bolts; function, applicability and advantage of roof bolting and cable bolting.

WEB LINK:

Session 24

LECTURE:

powered supports; systematic support rules; supporting scheme of development gallery.

WEB LINK:

Session 25

LECTURE:

B&P and L/W faces, depillaring district; withdrawal of support.

WEB LINK:

Session 26

LECTURE:

Conditions requiring stowing in mines; types of stowing; suitable materials for hydraulic stowing.

WEB LINK:

Session 27

LECTURE:

stowing plant and stowing range.

WEB LINK:

Session 28

LECTURE:

hydraulic gradient and hydraulic profile.

WEB LINK: