As a key pillar of the national economy, metal mines’ safe production is directly related to resource supply security and the safety of workers. However, extreme environments such as high ground pressure, high temperature, high humidity, and multiple hazards pose significant challenges to traditional safety technology models. Gas accidents such as gas explosions and toxic gas leaks are frequent, causing significant loss of life and property, and negatively impacting society. Gas detectors, as the “first line of defense” for mine safety, are reshaping the safety ecosystem through intelligent upgrades.
What are the harmful gases in mines?
Mine operating environments are complex and volatile. Ground air enters the mine shaft and becomes mine air. Major threats include: decreased oxygen content; increased levels of toxic and harmful gases; increased dust concentration; and changes in the air’s physical state, such as temperature, humidity, and pressure.
Carbon Monoxide (CO)
Carbon monoxide is a colorless, odorless gas that is slightly soluble in water, flammable, and explosive. It can explode at concentrations of 12.5% in air.
Carbon monoxide is highly toxic. The degree of poisoning is related to the concentration, duration, respiratory rate and depth, and the individual’s physical condition. A notable characteristic is a cherry-red discoloration of the mucous membranes and skin.
The main sources of carbon monoxide in mines include blasting operations, mine fires, and gas and dust explosions.
Hydrogen sulfide (H2S)
Hydrogen sulfide is a colorless, slightly sweet gas with a slight rotten egg odor. It is highly soluble in water and explosive at concentrations of 4.3% to 46%. Hydrogen sulfide is highly toxic and can cause blood oxygen deprivation, leading to poisoning.
The main sources of hydrogen sulfide in mines include the decay of organic matter such as pit wood; the hydration of sulfur-containing minerals; and release from accumulated water in old goafs and lanes.
Sulfur dioxide (SO2)
Sulfur dioxide is a colorless gas with a strong sulfurous and sour odor. It is highly soluble in water and has the highest density among the harmful gases underground, often accumulating at the bottom of underground tunnels.
Sulfur dioxide is highly toxic. Sulfur dioxide in the air reacts with water to form sulfuric acid, which is irritating to the eyes. Miners call it “blinding gas.”
The main sources of sulfur dioxide in mines include: the oxidation and combustion of sulfur-containing minerals; blasting within sulfur-containing minerals; and escaping from sulfur-containing materials.
Methane (CH4)
Methane is the most common asphyxiating and explosive gas. It is lighter than air, easily diffuses, has strong permeability, and can burn or explode. Gas explosions are one of the major hazards in coal mines.
The main source of methane in mines is coalbed methane.
Nitrogen dioxide (NO2)
Nitrogen dioxide is a reddish-brown gas with a strong, pungent odor and is readily soluble in water.
The main hazard of nitrogen dioxide is that it forms highly corrosive nitric acid when dissolved in water, which is highly irritating and corrosive to the eyes, respiratory mucosa, and lungs. Nitrogen dioxide poisoning has an incubation period, and victims may develop yellow spots on their fingers.
The main source of nitrogen dioxide is: underground blasting.
Ammonia (NH3)
Ammonia is a colorless, strongly smelling gas that is readily soluble in water. When the ammonia concentration in air reaches 11-14%, it will ignite in the presence of open flames. The primary hazard of ammonia is its irritation to the skin and respiratory mucosa, which can cause laryngeal edema.
Major sources of ammonia include blasting, gel injection, water firefighting, and naturally occurring ammonia in some rock formations.
Hydrogen (H2)
Hydrogen is a colorless, odorless, and non-toxic gas. Its primary hazard is its explosiveness. When the hydrogen concentration in air is 4% to 75%, an explosion hazard exists.
Major sources of hydrogen include hydrogen released during charging of underground batteries, hydrogen naturally occurring in some moderately metamorphic coal seams, and hydrogen generated during coal oxidation.
Mine Gas Safety Solution
Chicheng Electric’s mine gas safety solution utilizes gas detectors, temperature and humidity sensors, and liquid level meters to monitor gas concentrations and environmental parameters in real time across various areas, centrally managing and monitoring the data.
By analyzing, analyzing, and assessing the monitoring data, safety managers can gain a comprehensive and timely understanding of gas leak activity in each area and take appropriate measures to keep on-site gas concentrations within safe limits. This effectively addresses the pain points of traditional manual inspections, such as limited blind spot coverage, delayed response times, and data silos.
Portable gas detectors offer a portable safety line.
Chicheng Electric’s CD3(A) multi-parameter gas detector and JD4 multi-parameter gas detection alarm effectively ensure safety in the mining, beneficiation, and smelting processes of tin, iron, and copper mines. Equipped with industrial-grade, high-precision sensors, these instruments simultaneously detect key gas parameters such as carbon monoxide, oxygen, and nitrogen dioxide. Their large LCD display clearly displays real-time data even in low-light conditions underground. The instruments feature triple alarms – audible, visual, and vibration – and integrate robust protection, multi-gas simultaneous measurement, precise monitoring, and intelligent early warning, creating a 24/7, on-the-go safety line for workers!
Importantly, Chicheng Electric’s CD3(A) multi-parameter gas detector and JD4 multi-parameter gas detection alarm have obtained Mining Product Safety Mark Certificates (KA and MA) and are used in multiple mine operations. With reliable quality assurance and practical support, users can purchase with confidence!
In mining operations, every fluctuation in gas concentration can mean a life-or-death difference. Leveraging its technological foundation, Chicheng Electric’s intelligent gas detectors create a mine-wide “safety net,” enabling miners to move from fear to peace of mind. With the deep integration of technologies such as the Internet of Things, big data, and cloud computing, Chicheng Electric is helping mine safety move towards “zero accidents and zero casualties”!
