Methane Control | Indian Minerology

-

Part 4: Methane Control

Key Learning Objective: Master methane management techniques as per CMR 2017 Chapter VII (Reg 112-132), DGMS Methane Policy 2020, and practical opencast/underground control measures.

4.1 Methane Monitoring Procedures

🚨 STATUTORY METHANE LIMITS 🚨
Return Airway: <1 continuous="" face:="" goaf:="" monitoring="" small="">
Location Max CH₄ Limit Action Required CMR Reference
Return Airway 1.0% Increase ventilation CMR 117(1)
Working Face 1.25% Stop mechanical extraction CMR 117(2)
Goaf Edge 0.5% Seal barriers, withdraw men CMR 132
Intake Airway 0.5% Investigate source CMR 116

4.2 Ventilation Strategies for Methane Control

💨 Auxiliary Ventilation

Auxiliary Fan
  • Forcing/ Exhausting type
  • Min 3m/s velocity
  • Flexible ducting
  • 30,000 CMH capacity

🌪️ Main Fan Management

Main Fan
  • Water-gauge monitoring
  • Auto-reverse facility
  • 75,000-5,00,000 CMH
  • Daily quantity survey

🛠️ Stone Dusting

Stone Dust
  • 15% incombustible content
  • Roadways: 2.5kg/m²
  • Goaf: 40% coverage
  • Monthly sampling

4.3 Methane Drainage Systems

Mandatory for gassy seams (>9m³/tonne gas content)

Drainage Methods:

  • In-seam boreholes: 50-100m horizontal
  • Goaf edge drainage: Vertical wells
  • Pre-drainage: Before extraction
  • Ventilation through pipes: To surface
  • Cross-measure drilling: 30° angle

Success Criteria: CH₄ reduced to <0 .5="" at="" face="" p="">

4.4 Emergency Response for Methane Alarms

🚨 METHANE ALARM PROTOCOL 🚨

1% CH₄ = YELLOW ZONE → 1.25% = RED ZONE

  1. All electrical equipment OFF
  2. Stop conveyor/haulage
  3. Increase ventilation (aux fans)
  4. Withdraw to fresh air base
  5. Continuous monitoring every 15 min
  6. Manager approval for re-entry

4.5 Preventive Measures

  • Pre-shift gas checks (mandatory)
  • Two-fan ventilation systems
  • Methane forecasting from degasification data
  • Gas emission rate surveys
  • Seal integrity testing (weekly)
  • Power cut-off at 1.5% CH₄ (auto)

⚠️ Exam Must-Know Facts:

  • CMR 117(3): >1.5% CH₄ = All men withdrawn
  • Aux fan capacity: 0.3m³/s per 100m duct
  • Stone dust sampling: Form V-26
  • Methane ignition temp: 540-630°C
  • Goaf drainage: 50% emission control

Comments

Post a Comment

Popular posts from this blog

ADVANCING AND RETREATING LONGWALLS

-
Image
ADVANCING AND RETREATING LONGWALLS:- Advancing Longwalls:- In this method, the face start point is close to the main headings, usually leaving a barrier pillar to protect them. Once the face equipment is installed, extraction commences working away from the main headings towards the block limit. Obviously the main and tailgates do not exist prior to the start of extraction and have to be formed at each end of the face as mining progresses. The gate roads are effectively in the goaf and a false rib has to be installed on one side, usually by constructing a small pillar, sometimes using stone cut from the roof in thin seams or using some type of cementitious material brought into the mine. Such gate roads tend to require a very heavy support system (yielding steel arches have often been used). Principle of advancing longwall Advancing longwalls were once common in Europe in relatively thin seams where packs were constructed using stone, which had ...
Read more continue...... »

Continuous Miner

-
Image
Continuous Miner:- Continuous Miner:- A continuous miner is a mining machine that produces a constant flow of ore from the working face of the mine. The machine continuously extracts as it is loading coal with a cutting steel drum and conveyor system. Continuous miners are typically used in room and pillar mining operations. The continuous miner is different from conventional or cyclical mining methods, which halt the extraction process in order for ore-loading to proceed. Continuous miners, which began to take off in the mining industry in the 1940s, make up of 45 percent of the underground coalmine production. Today, continuous miners are being developed as driverless machines controlled via remote control. History:- Early Miners:- The continuous miner has been available in some form since the late 1800s. The first machine to resemble a continuous miner was known as the English Channel Machine. The pneumatically driven machine could travel 1.5 miles (2...
Read more continue...... »