| Abstact:With the rapid development of China's nuclear power and nuclear military industry,the sustainable supply of nuclear raw materials will have an increasingly important impact.Natural uranium is an important metal raw material in nuclear materials,and the extraction of natural uranium from ore is its main source.The heap leaching of uranium-molybdenum ores containing uranium is a common method for the leaching of uranium-molybdenum ore.Heating the heap-leaching uranium-molybdenum ore is a key process for improving the leaching efficiency of uranium-molybdenum ore.At present,the heating process of heap leaching uranium-molybdenum silos has problems such as long heating period,uneven heating temperature distribution and low energy utilization rate,which has great influence on uranium element leaching efficiency.Therefore,in this paper,the fluid software fluent is used to simulate the steam heating process of the bunker,and the simulation results are analyzed.According to the deficiencies in the results,the structure of the bunker is improved and the parameters are optimized to improve the temperature uniformity in the bunker during heating.Shortening the heating cycle,improving energy efficiency,and finally achieving the goal of increasing the efficiency of uranium element leaching,the research project is of great significance for improving uranium element production and saving energy.There are many influencing factors in the heating process of heap leaching uranium-molybdenum silos.The main factors are the steam inlet velocity V,the inlet diameter d and the diameter of the floral tube D.These parameters are optimized to obtain the effect of heating the silo.Uniform temperature distribution of the optimal parameter combination.The main research contents and results of this paper are as follows:(1)A three-dimensional model of the heated silo and a fluid zone model were established.Based on the principle of heat exchange and the convection heat transfer principle,the fluent software was used to simulate the heating process of the 3D model of the silo,and the temperature distribution cloud map was analyzed,and the temperature of the heating process monitoring point was increased.Graphs,velocity profiles,temperature distribution maps for each plane,and changes in the temperature uniformity coefficient show that the temperature inside the silo rises slowly,the temperature distribution inside the silo is very uneven,and the heating time is longer.(2)The structure of the silo is improved.On the basis of the original silo,a row of air intakes is added at the bottom of the silo,four air outlets at the bottom are changed into air intakes,and a flower pipe is added in the middle of the silo to improve After the numerical simulation of the structure,comparing the results before and after improvement can be obtained: After the improvement of the heating effect,shorten the heating cycle,temperature uniformity has also been greatly improved.(3)The main parameters affecting the heating process of the bunker include the steam inlet velocity V,the inlet diameter d,and the diameter of the floral tube D.The three parameters are studied using the single-factor optimization method,and then the orthogonal test design method is used.The three parameters were optimized using the three factors and five levels.The results of the orthogonal experiment indicated that the primary and secondary sequences that affect the heating process of the silo and the uniform temperature distribution parameters were V>d>D,and the best combination of the three parameters was obtained.The optimal combination of parameters affecting the heating effect and temperature uniformity of the silo is the inlet velocity V = 1.2m/s,the inlet diameter d = 200 mm,and the floral tube diameter D = 500 mm. |
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