Fusheng Lead-zinc Mine Ventilation And Cooling Methods

High temperature in mine pit severely affects working crew's efficiency and health, even could probably lead to accidents, which put great threats to mine production and management. Research of technique in temperature reduction of mine pit is becoming one of the important fields in mine safety study at home and abroad. Technique studies of temperature reduction varies, mainly include studies on method of ventilation inside the pit, manual cooling, sprinkling, compressed air expansion, and precooling of the incoming air, among of which, ventilation is the main object of study. With the main theme of temperature reduction by ventilation, and the main object of temperature reduction project for lead zinc mine pit of Fu Sheng, this thesis firstly discussed about the heat conduction of rocks, and then conducted research and comparison between ventilation cooling method and partial cooling method, based on theory of mine ventilation, thermodynamics and aerodynamics. With reference to former research achievements, this thesis mainly discussed about the followings.1. Temperature control based on thermal properties of rocks. With analysis of thermodynamic parameter of rocks and influencing factors, discussed about the theory and method of heat control and temperature reduction from the perspective of heat conduction of rocks.2. The modified formula of heat conduction for under passage inside mine pit. For passage with relatively great partial and frontal resistance, modified the traditional heat conduction formula, to make the theory, process and results more practical, which is better for ventilation grid structure arrangements. Meanwhile, this thesis analyzed the contradiction between size reduction to reduce heat radiation and size enlargement to reduce wind pressure. Referring to formula for friction resistance and heat conduction, and based on the circumference of passage section, the thesis attempted to infer the relation between pressure of the fan and temperature of the passage. On the premise of temperature reduction, the attempt provided proof for optimization of choosing fans.3. With reference to formula of heat conduction and natural ventilation pressure, this thesis discussed about the calculation method for natural ventilation pressure from the perspective of deep pit heat conduction. When the temperature for through airshaft is constant, the natural ventilation pressure tends to be stable. Mechanical ventilation could lead to the formation of stable and natural ventilation pressure. According to the value of natural ventilation pressure, fans of lower capacity could be chosen to save energy.4. This thesis discussed about the calculation method with heat factor involved in ventilation network. Air expansion under heat in one section caused heat transfer resistance. Referring to the relation between friction resistance of passage ventilation and specific friction resistance, analyzed the design formula for heat transfer resistance, probed into the concept and formula of heat transfer resistance, and introduced the heat transfer resistance into ventilation network, to analyze its effects on ventilation.5. This thesis analyzed the application of compressing air to reduce temperature in one section or in the middle, and probed into its economic effects. This thesis firstly discussed about confirmation of isenthalpic, isenthalpic formula and the method of choosing optimized high-pressure spot for compressor, and then studied on three manway shafts in the middle of lead zinc mine of Fu Sheng. With the key of compressed air expansion, combined with heat transfer equation, this thesis discussed about the temperature reduction in two different ways for one section or middle section because of compressed air expansion.6. This thesis discussed about calculation method of water sprinkling quantity and analyzing method of temperature reduction effects, and suggested control measures for high humidity. For those mine pits close to water source, with better water intake and drainage, water sprinkling could be used for temperature reduction, but it might raise the humidity inside the pit. Therefore, this thesis not only discussed about temperature reduction by water sprinkling, but also analyzed the control method for humidity inside the mine pit.7. Temperature reduction by ventilation underground is the main method in this these, and this thesis also discussed about way of compressed air expansion and sprinkling. This thesis had a research into high temperature for lead zinc mine of Fu Sheng. With the implementation of the project, the average temperature of the mine decreased from 33.7℃to 26.30℃; temperature for No.2 passage in 1496 main laneway decreased from 28.07℃to 26.89℃; temperature of manway shaft decreased from 28.09℃to 27.32℃; temperature for mining surface in the 1550 main laneway is 26.40℃, and the humidity is 0.0082 kg/kg; temperature for passage in the 1550 and 1526 main laneway remains 25.40℃, and the humidity keeps 0.0120kg/kg. The application of ventilation method for lead zinc mine of Fu Sheng had good outcome in temperature reduction.