1. The underground air quality should meet the following requirements:
1 The dust content of the wind source and the mining face should not exceed 0.5mg/m 3 ;
2 The air composition calculated by volume in the inlet surface of the underground mining face, the oxygen should not be lower than 20% , and the carbon dioxide should not be higher than 0.5% ;
3 The harmful substances in the air at the underground operation site shall comply with the current national regulations on occupational exposure limits for harmful factors in the workplace;
4 Mines with radioactive elements, the concentration of radon and its daughters in the underground air should comply with the relevant national regulations.
Second, the mine should take the following dust prevention measures:
1 Do not pile sand and other dust-producing materials near the wellhead of the wind cage. Dust-proof measures shall be taken for the discharge of cement, sand and other materials;
2 It is not advisable to set up ore slipping wells in the main wind tunnels;
3 separate ventilation and dust removal devices shall be provided in the pit breaking system;
4 Purification measures shall be taken for mines with excessive dust content in the wind flow;
5 Mining and excavation work faces shall adopt comprehensive measures such as wet rock drilling, spray watering, water sealing blasting, wall washing, ventilation and dust removal and personal protection;
6 should be equipped with dust and exhaust gas measurement and analysis instruments.
3. The air temperature of the inlet and outlet tunnels and the underground mining face shall comply with the following requirements:
1 The air temperature in the wind inlet lane should be higher than 2 °C in winter ; when it is lower than 2 °C, there should be warm air measures;
Weather conditions 2 mining operations should be consistent with the location specified in Table 1, does not meet the provisions of Table 1 should be taken to cool down or other protective measures.
1 In the severe cold area, all lifting wells and wind wells as safety exits shall have insulation measures to prevent icing at the wellhead and wellbore;
2 The air entering the mine should not be heated directly by open flame;
3 In addition to radioactive mines, it is advisable to use the rock temperature of existing waste tunnels or goafs to preheat the cold air sent into the well;
4 large and medium-sized mines should be preheated with air heaters;
5 Small mines without concentrated heat source. The mine antifreeze can be preheated by hot air stove. The position of the hot blast stove should be such that the air entering the wellbore is not polluted and should meet the fire protection requirements.
5. The mine cooling should meet the following requirements:
1 When using non-artificial cooling to cool down, according to the specific conditions of the mine, comprehensive use of natural cold source, increase of air supply or increase local wind speed at the concentration of workers, ventilation methods that are conducive to cooling, avoiding downhole heat sources, and isolating or reducing heat sources should be adopted. Measures to dissipate heat, drain or block hot water, personal protection, etc.
2 When using artificial cooling to cool down, it should be based on mine geological conditions, development system, roadway layout, mine ventilation system, cooling and cooling range, depth of mining, cold load, mine water inflow and water quality and water temperature, return air volume and temperature, degree of mechanization of mining , heat and the mine conditions similar experience, after technical and economic feasibility, the choice of underground or mobile air-conditioning refrigeration and other local air cooling measures, ground central air conditioning systems, ground and underground combined air-conditioning cooling system embodiment; 3 radioactive mines , should not use the existing waste tunnel or gob to cool down.
1 The dust content of the wind source and the mining face should not exceed 0.5mg/m 3 ;
2 The air composition calculated by volume in the inlet surface of the underground mining face, the oxygen should not be lower than 20% , and the carbon dioxide should not be higher than 0.5% ;
3 The harmful substances in the air at the underground operation site shall comply with the current national regulations on occupational exposure limits for harmful factors in the workplace;
4 Mines with radioactive elements, the concentration of radon and its daughters in the underground air should comply with the relevant national regulations.
Second, the mine should take the following dust prevention measures:
1 Do not pile sand and other dust-producing materials near the wellhead of the wind cage. Dust-proof measures shall be taken for the discharge of cement, sand and other materials;
2 It is not advisable to set up ore slipping wells in the main wind tunnels;
3 separate ventilation and dust removal devices shall be provided in the pit breaking system;
4 Purification measures shall be taken for mines with excessive dust content in the wind flow;
5 Mining and excavation work faces shall adopt comprehensive measures such as wet rock drilling, spray watering, water sealing blasting, wall washing, ventilation and dust removal and personal protection;
6 should be equipped with dust and exhaust gas measurement and analysis instruments.
3. The air temperature of the inlet and outlet tunnels and the underground mining face shall comply with the following requirements:
1 The air temperature in the wind inlet lane should be higher than 2 °C in winter ; when it is lower than 2 °C, there should be warm air measures;
Weather conditions 2 mining operations should be consistent with the location specified in Table 1, does not meet the provisions of Table 1 should be taken to cool down or other protective measures.
Table 1
4. Mine anti-freezing should meet the following requirements: 1 In the severe cold area, all lifting wells and wind wells as safety exits shall have insulation measures to prevent icing at the wellhead and wellbore;
2 The air entering the mine should not be heated directly by open flame;
3 In addition to radioactive mines, it is advisable to use the rock temperature of existing waste tunnels or goafs to preheat the cold air sent into the well;
4 large and medium-sized mines should be preheated with air heaters;
5 Small mines without concentrated heat source. The mine antifreeze can be preheated by hot air stove. The position of the hot blast stove should be such that the air entering the wellbore is not polluted and should meet the fire protection requirements.
5. The mine cooling should meet the following requirements:
1 When using non-artificial cooling to cool down, according to the specific conditions of the mine, comprehensive use of natural cold source, increase of air supply or increase local wind speed at the concentration of workers, ventilation methods that are conducive to cooling, avoiding downhole heat sources, and isolating or reducing heat sources should be adopted. Measures to dissipate heat, drain or block hot water, personal protection, etc.
2 When using artificial cooling to cool down, it should be based on mine geological conditions, development system, roadway layout, mine ventilation system, cooling and cooling range, depth of mining, cold load, mine water inflow and water quality and water temperature, return air volume and temperature, degree of mechanization of mining , heat and the mine conditions similar experience, after technical and economic feasibility, the choice of underground or mobile air-conditioning refrigeration and other local air cooling measures, ground central air conditioning systems, ground and underground combined air-conditioning cooling system embodiment; 3 radioactive mines , should not use the existing waste tunnel or gob to cool down.
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