0 Introduction
In the process of infrastructure construction and mining of underground mines, it is necessary to excavate many wells and roadways to form a development system and to carry out mining, cutting, and recovery. When excavating shafts, in order to dilute and discharge the ore dust generated during the excavation process and the polluted air such as gun smoke generated after the explosion, create good mine climatic conditions, and ensure the safety and health of employees, continuous local ventilation of the driving face is required. The use of local ventilation to improve the air quality of the working face is very common. Usually the ventilation condition of the single-headed roadway is very poor, and the ventilation problem has not been solved well. According to the foreign advanced mine experience, the key is whether the appropriate diameter ventilation duct is used in the local ventilation, and the key to whether the appropriate diameter ventilation duct can be used depends on the cross-sectional size of the single-headed roadway. In this paper, the calculation formula for the diameter of the economic ventilation duct is obtained through research. For example, many working faces of Fankou lead-zinc mine use large-scale diesel machinery and equipment, and the cross-sectional area of the roadway is large.
According to relevant books on mine ventilation, the general principles for selecting the diameter of local mine ventilation ducts are: When the air supply distance is within 200m and the air supply volume is not more than 2-3m3/s, the diameter of the mine ventilation duct should be 300-400mm;When the air supply distance is 200-500m, the diameter of the applied mine ventilation duct is 400-500mm;When the air supply distance is 500-1000m, the diameter of the applied mine ventilation duct is 500-600mm;When the air supply distance is greater than 1000m, the diameter of the mine ventilation duct should be 600-800mm. Moreover, most manufacturers of mine ventilation ducts specify their products in this range. Therefore, the diameter of mining ventilation ducting used in metal and non-metal underground mines in China has basically been in the range of 300-600mm for a long time. However, in foreign mines, due to the use of large-scale equipment, the cross-sectional area of the roadway is large, and the diameter of the local mining ventilation ducts is often larger, some reaching 1500 mm, and the diameter of the branch mine ventilation ducts is generally more than 600 mm.
In this paper, the calculation formula of the diameter of the economic mine ventilation duct is studied under the minimum economic conditions of the purchase cost of the mining ventilation ducts, the electricity consumption of the local ventilation through the mining vent duct, and the daily installation and maintenance of the mining vent ducts. Local ventilation with economical ventilation duct diameter can achieve better ventilation effect.
To be continued…
Post time: Jul-07-2022
