Coal fire

1. MAN MADE DISASTERS
COAL FIRE
PRESENTEDBY
OMKARSWAMI CH [9917]
PARVATI DU [9918]
PRESENTED TO
Dr.KIRAN B O
ASST. PROFESSOR
DEPT. OF ENVIRONMENTAL SCIENCES
COA HANUMANAMATTI

2. The term "Coal fire" refers to a burning or smoldering coal
seam, coal storage pile or coal waste pile.
Two major causes have been identified for coal fires
 Natural causes:coal seam or dust can be exposed by the
erosion or a subsidence event, strike by lightning or
ignite by a wildfire.
 Human causes:friction, electricity or oxygen can ignite
coal peat or dust during regular extraction, illegal
mining, transportation.
Introduction

3. AnnaWasteDump,AachenAnthraciteCoalField, Alsdorf,
Germany
Brennender Berg(BurningMountain),Saarland,Germany
SmokingHillsinCanada'sNorthwestTerritories
BenxihuColliery(1942)–China
CourrieresCoalMine(1906) –France
MitsubishiHojyoCoalMine(1914) -Japan
OaksCollieryExplosion(1866) -UnitedKingdom
DhanbadCoalMine(1965and1975) -India
Active coal seams and coal fire mines

4. COAL FIELDS-WORLD

6. 'Spontaneous Combustion' means that coal
can start to burn without any recognizable
outer influence.
Spontaneous combustion depends, amongst
others:
 On coal type
 Temperature
 Availability of oxygen
 Exposure to surface
 Thickness of coal seam
Spontaneous combustion

7. Based on barometric pressure, underground
coal fire development
Stage I
 Cracks and fissures allow air to enter the
ground and reach abandoned mine
workings or sealed-off areas.
 Breathing starts as a result of changing
barometric pressure and residual coal is
supplied with sufficient oxygen to ignite.
 The process of spontaneous combustion
has begun.

8. Stage II
Once sufficient draught has been
created by the spreading fire, areas of
exclusive in- and out breathing
develop.
A continuous air circulation loop forms
that enables the fire to progress
steadily.

9. CAUSES OF DISASTER IN COAL MINE
 Presence of explosive mixture
Firedamp alone
Coal dust alone
 Suitable source of ignition
 Accidental fire
 Spontaneous heating
1. Explosion
2. Roof fall
3. Fire

11. Chemical indication / Fire Ratios
The composites of gas concentrations
Some of these are as follows:
Graham's ratio [CO]/402
Willet's ratio CO2/[excess N2 + CO2 + combustibles]
As a thumb rule it can be taken that
-0.4% or less indicates normal value
-0.5% necessity for a thorough a checkup
1% existence of heating-
2% serious heating approaches active fire action
fire with certainty
23% and aboveDiem tubingdd notes
DETECTION OF SPONTANEOUS COMBUSTION

17. IMPACT ON ATMOSPHERIC ENVIRONMENT
 According to the IPCC, Release of carbon dioxide is
one of the major cause to climate change and global
warming.
 Coal is the largest contributor to the human-made
increase of CO, in the atmosphere.
 According to Guan et al.,
 Coal fires in northern China discharge into the
atmosphere each year
490,200 t of carbon monoxide (CO),
514,700 t of sulfur dioxide (SO2),
300,000 t of nitrogen dioxide (NO2),
112,000 t of dust,as well as other harmful gases

18. IMPACT ON SOIL ENVIRONMENT
 Coal fires change the
physico-chemical properties
of soil.
 Soil becomes fragile with
very low organic matter
content and only small
numbers of microorganisms

19. IMPACT ON HUMAN HEALTH
Coal tar is a respiratory carcinogen
identified by the International Cancer
Research Institution of the World Health
Organization.
Arsenic contained in coal fire discharge can
cause chronic intoxication with after-effects
such as pigment deficiency, over-
pigmentation, and skin cancer.

20. COAL FIRE MITIGATION
 Trench cutting and filling with incombustible
materials
 Surface sealing with soil (soil with high water
retaining capacity)
 Creation of water pools on the surface, water
circulation under pressure, flooding of fire areas
 Inert gas and/or foam infusion
 Cementing and grouting, flushing with bentonite
and/or fly ash
 It was found that a 10 cm layer of bentonite can
reduce air permeation by up to 90 %.

21. CONCLUSION
 India coal mining industry
strive toward zero disaster
 proper Vigilance
 Environmental tele-
monitoring in fire prone areas.