Industry: Mine extraction

Mine underground gas and multi-component toxic gas monitoring solution

MA certified mining equipment, featuring dual coverage of fixed and portable models, with dual power supply from lithium battery and solar energy

Industry Pain Points

Underground mines are characterized by extremely complex working conditions involving a quintuple combination of "gas (CH4) + carbon monoxide (CO) + carbon dioxide (CO2) + hydrogen sulfide (H2S) + hypoxia", coupled with high dust levels, high humidity, and an explosion-proof environment. The lower explosion limit of coal mine gas is 5%, the upper limit is 16%, and a concentration of 1% underground must trigger evacuation and immediate cessation of mining activities. Spontaneous combustion of coal seams produces CO (CO > 24 ppm, indicating a continuous increase, which must be addressed immediately according to the Coal Mine Safety Regulations). The concentration of H2S in sulfur-bearing coal seams can suddenly reach hundreds of ppm. After blasting, the concentration of NO2 and CO in the mined-out area is extremely high. The monitoring system must provide 24/7 full coverage, be explosion-proof (Ex d I Mb level), vibration-resistant, and dust-proof (IP67), and the data must be integrated into the coal mine safety monitoring system (KJ system) and the regulatory platform of the Emergency Management Bureau. A single instance of gas overrun and missed reporting will result in a fine of 500,000 yuan and production suspension for rectification.

Solution Overview

Yourui'an complies with the coal mine underground gas monitoring scheme of the AQ 1029-2019 + GB 3836 series: ① Fixed multi-parameter integrated substation for CH4 + CO + O2 + CO2 + H2S + wind speed + temperature, with deployment density strictly in accordance with Article 487 of the "Coal Mine Safety Regulations"; ② Mine-used intrinsically safe portable 4-in-1 (CH4 + CO + O2 + H2S) device, one per team, with mandatory startup upon entering the mining face; ③ Protocol-level docking with the coal mine safety monitoring system (KJ95N / KJ90 / KJ70) (CAN bus / MA standard), achieving remote real-time monitoring + over-limit power cut-off + automatic personnel evacuation; ④ Mobile portable gas sampling instrument for before and after blasting (CO + NO2 + oxygen), meeting the special requirements of AQ 1052 for ventilation after blasting. Key nodes: fully mechanized mining face, fully mechanized tunneling face, return air lane, coal bunker, belt conveyor lane, electromechanical chamber, and shaft bottom yard.

## Key Locations (Mandatory Requirements According to Regulations)

– **Fully mechanized mining/tunneling face**: CH4 is detected at a distance of 5m from the heading in the return air duct of the working face; T2/T3 alarm thresholds are 1.0%/1.5%
– **Return air duct / main return air**: Conduct joint measurement of CH4, CO, and wind speed. An alarm must be triggered if CH4 > 0.75%
– **Near the mined-out area**: CO (spontaneous combustion monitoring) + CO2 (asphyxiation), the upward trend of CO is more important than its absolute value
– **Coal bunker / Tripper room**: dust + CO + CO2
– **Electromechanical chamber / substation**: CH4 + CO + smoke
– **Return air shaft portal (ground level)**: Total return air concentration of CH4 + CO, triggering ground-level emergency response if exceeding the limit

## Key Technical Specifications

– Explosion-proof: Ex d I Mb (specially designed for underground coal mines)
– Protection: IP67 (high dust + water droplet)
– Operating temperature: -20℃ ~ +50℃
– Communication: CAN bus / RS485, compliant with KJ95N protocol
– Mine-used product safety mark (MA)
– Battery life: portable ≥ 14 hours (for one shift)

## Implementation Essentials

1. **Over-limit power-off automatic logic**: If CH4 > 1.5%, immediately shut down the extraction machine + local fan → evacuate personnel
2. **CO Trend Alarm**: CO increase > 5 ppm/h for 3 consecutive hours → spontaneous combustion warning, initiate nitrogen injection / grouting
3. **Special Monitoring After Blasting**: After blasting, it is necessary to wait until CO < 0.0024% and NO2 < 0.00025% before re-entry
4. Calibration cycle: Calibrate CH4 with standard gas every 7 days (routine calibration by gas inspector) + calibrate at the instrument verification center every 6 months

## Regulatory Basis

– Articles 487-509 of the "Coal Mine Safety Regulations" (2022 Edition)
– AQ 1029-2019 "General Technical Requirements for Coal Mine Safety Monitoring Systems"
– AQ 1052-2008 "Requirements for Mine Air Testing after Blasting"
– GB 3836-2021 "Electrical Apparatus for Explosive Gas Atmospheres"
– MT/T 1004 Series Standard for Monitoring and Control Devices Used in Coal Mines

## Applicable Customers

National Energy / Middling Coal Energy / Shanxi Coking Coal / Yanzhou Mining Group / Shaanxi Coal and other coal groups; non-coal mines (metal / nonferrous / chemical mines); portable equipment for mine rescue teams.

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