Coal India Mining Overman Interview Questions, Process, and Tips

The suitable bench height for a 2cu.m shovel depends on various factors such as the type of material being mined and the equipment used.

• The bench height should be determined based on the reach and capacity of the shovel.

• It should allow for efficient loading and dumping of material.

• The bench height should also consider the stability and safety of the mining operation.

• Factors like the type of material, equipment limitati...read more

The maximum width of the gallery in Indian coal mines varies depending on the specific mine and its regulations.

• The maximum width of the gallery is determined by safety regulations and guidelines set by the Indian government.

• Different coal mines may have different maximum width requirements based on factors such as the type of coal being mined, the depth of the mine, and the mining method used.

• For example, in undergrou...read more

The maximum length of the trailing cable depends on various factors such as power requirements, voltage drop, and safety regulations.

• The length of the trailing cable is determined by the distance between the power source and the equipment it needs to supply.

• Power requirements of the equipment play a role in determining the maximum length of the cable.

• Voltage drop, which can affect the efficiency of power transmission, ...read more

Detonating fuse consists of a core

• The core of a detonating fuse is the central part that initiates the explosion

• The core is typically made of a highly reactive material, such as a mixture of powdered metals or chemicals

• The core is surrounded by a protective casing to prevent accidental ignition

• Examples of core materials include lead azide, mercury fulminate, or PETN

The VOD of detonating fuse is the velocity at which the detonation wave travels along the fuse.

• VOD stands for Velocity of Detonation.

• It is a measure of how fast the detonation wave propagates through the fuse.

• The VOD of a detonating fuse depends on factors such as the type of explosive used and the composition of the fuse.

• A higher VOD means the detonation wave travels faster, resulting in a quicker explosion.

• Different ...read more

The priming charge in a detonator is the initial explosive charge that initiates the main explosive charge.

• The priming charge is a small amount of explosive material that is sensitive to heat, shock, or friction.

• It is designed to ignite quickly and reliably to initiate the main explosive charge.

• The priming charge is usually contained within a small metal or plastic capsule.

• Examples of priming charges include lead azide...read more

A sheathed explosive is coated with a protective covering.

• The sheath provides a layer of protection to the explosive material.

• The sheath can be made of materials like plastic or rubber.

• The purpose of the sheath is to prevent accidental ignition or detonation.

• Examples of sheathed explosives include dynamite and blasting caps.

The gelling agent in slurry explosive is typically a mixture of water and a thickening agent.

• The gelling agent is used to increase the viscosity of the explosive mixture.

• Common thickening agents used in slurry explosives include guar gum, carboxymethyl cellulose (CMC), and xanthan gum.

• The gelling agent helps to suspend solid particles in the explosive mixture, allowing for better distribution and control of the explosi...read more

The VOD of emulsion explosive refers to its Velocity of Detonation.

• VOD is a measure of how fast the explosive reaction propagates through the material.

• It is an important characteristic for determining the efficiency and safety of explosive materials.

• Higher VOD explosives are typically used for blasting hard rock formations.

• Lower VOD explosives are used in situations where a controlled and less destructive explosion is

The output capacity of the dragline with 4.5 to 7.5 cu.m is in million cu.m per year.

• The output capacity of the dragline depends on the size of the bucket it uses.

• A larger bucket size allows for a higher output capacity.

• The dragline's efficiency and operating conditions also affect its output capacity.

• The output capacity can be calculated by considering the average number of cycles per hour and the bucket fill factor.

• F...read more