Simulation And Optimization Of Rotary-Distribution-Air Burner Scheme In Copper Flash Furnace

Flash furnace is the important equipment in copper metallurgical process because of its great influence on the quality of matte and cost of production. Taking advantages of modern numerical simulation technology, understandings of the multi-phase flow inside the furnace and the distributions of fields such as velocity, temperature and concentration becomes possible, thus helpful for optimizations of operation parameters, improvement of gas-particle mixing and intensification of smelting process.Based on the structure of flash furnace and features of the flash smelting process, a numerical model was developed and a coupling computation of multi-phase flow was carried out with the commercial software FLUENT. An industrial test was then made to verify the numerical model. An deviation of less than 6.5% was found between the results of the simulation and the industrial test, which proves the reliability and accuracy of the simulation model.The main work and conclusions of this dissertation are as follows.(1) With the typical equipment and production conditions of the flash furnace, it can be obviously seen in the reaction shaft that the burning of concentrate particles delays and the gas-particle mixing intensity is not enough. This is the main reason which results in the high temperature area moving downwards, the smelting reaction condition worsening and the efficiency of oxygen usage decreasing.(2) A rotary-distribution-air burner scheme was put forward and a numerical simulation was proceeded. It turned out that the rotary-distribution-air is helpful to enhance the gas-particle mixing and smelting reaction efficiency. However, the dust generation rate may increase because gas influences more significantly on small particles.(3) Optimization numerical simulation was proceeded on radial and tangential components of the velocity of the distribution air. It can be concluded that the radial velocity of distribution air is the main force of distributing concentrate particles, while the tangential velocity of the distribution air is the main force of enhancing gas-particle mixing crosswise. So increasing the tangential velocity of the distribution air is helpful to enhance the gas-particle mixing and the smelting reaction process. However, the value of tangential velocity of distribution air should be controlled within a proper range in order to avoid eroding reaction shaft wall by concentrate which is overly distributed.(4) For the rotary-distribution-air burner scheme, it can be found that the value of the radial velocity of the distribution air must be controlled in a proper range. On this basis, a bigger radial/tangential momentum ratio of the distribution air is helpful to enhance the gas-particle mixing. Limited by the structure of the flash furnace modeled in this study, the radial/tangential momentum ratio of the distribution air is suggested to be controlled in the range of 0.33～1.