Spontaneous Heating & Incubation Period

-
               Spontaneous Heating

Definition:- The process of self heating of coal or other carbonaceous matter which results ignition is called Spontaneous heating.
The term spontaneous heating generally used for the coal whereas it is rare to the other materials.

 Process of Self Heating
The exposed coal to air starts absorbing oxygen and the chemical reaction starts which leads to the evolution of CO , CO2,  water vapour and heat. The process is very slow and the heat is not perceptible. This slow process slightly rise up due to rise in temperature and due to this the other part of coal become ready for oxidation. This slower process reaches a stage where temperature reaches the ignition point and the coal catches fire.
*It is necessary to take air sample constantly of return air, if any increase in CO percentage is detected then there is need of investigation.

                  Incubation Period

 The Incubation Period is the time in which the coal has to be extracted.
This is the very important term or can say important factor for spontaneous heating. It is because within this period every work should be completed and the area should be stopped.
There is no instrument to measure Incubation Period, only experience one can judge this period. The Incubation Period changes from seam to seam.


Popular posts from this blog

Secondary Blasting Technique

-
Image
In this post we will deal about the Definition of Secondary Blasting and types of Secondary Blasting . Some other Blasting are also available you can read about that. So let's start... Definition of Secondary Blasting The technique used to blast the boulders to achieve the fragmentation is called secondary blasting. This blasting is done to get the rocks which can be easily handled. Why and how to do secondary blasting? Why secondary blasting? We does secondary, in case when the primary blasting don't give fragmentation of rock which can be easily handled. The secondary blasting is followed after the primary blasting. How to do secondary blasting? To do secondary blasting we have to follow some methods which will give us batter resultant. These are here 1. Plaster shooting or Mud Capping.. As name indicates mud capping, the primer cartridge is place at top of Boulder and covered with mud. The blasting is done from the safe place by electric detonator...
Read more

Bord and Pillar Method

-
Image
Bord and Pillar Method of mining involves in the formation of roadways and the development of Mines. The first stage of working of Bord and Pillar Method is Called Development. In the development stage parallel roads are driven nearly at right angle to the first set. These roads are also use to join the separated coal blocks. The network of roads regularly increases as development of the mine. The second stage of working of Board and Pillar Method  of mining is called Depillaring. The Depillaring can be understood by It's name(De-Pillaring). In Depillaring the working involves in the extraction of coal from the Pillars. These are two stages of this mining method. The another name of Bord and Pillar method is "Pillar and Stall". For the application of Bord and Pillar Method there are some conditions to be full filled. Conditions are.... •The thickness of seam seam should be more than 1.5m. •There is less amount of dirt bands present in seams. •Se...
Read more

Shaft Sinking

-
Image
Q. What is shaft? Ans. :- It is a vertical or inclined entry made to touch seams. The word shaft is used for underground mining entrance. Q. Why shaft? Ans.:- The shaft is excavated after getting approval to mine the mineral bed by underground method of mining. Simple View of Working Shaft Shape of Shaft Generally the shaft are of circular in shape but in some mines it is of rectangular in shape. The circular shafts are best because they resist heavy side pressure and offers least rubbing surface area for ventilation. Bricking and concreting job are easy and diameter of these shaft may be varies from 4.2mts to 6.7mts. ◆The shaft sinking process is costliest and time taking process. So it is necessary to drill pilot hole within the radius of 50m of main shaft which has to be drill. This pilot hole give us an idea about the rock and how we have to encounter those problem which will we face during shaft thinking. From this we will get a data about       ...
Read more