硫铁矿沸腾焙烧炉多相流动反应
特性的数值模拟研究
穆玺文,张浩*,安希忠
多金属共生矿生态化冶金教育部重点实验室,东北大学冶金学院,沈阳,110819
摘要:沸腾焙烧炉作为硫铁矿焙烧制酸流程中的第一步,其能否稳定运行对整套工艺至关重要。由于当前沸腾焙烧炉大多工作年限较久,易出现炉内温度失稳、残硫率升高等问题。鉴于此,本研究采用双流体方法对硫铁矿在沸腾焙烧炉内的多相流动反应特性进行数值模拟研究。首先通过与现场数据及相关文献结果进行对比,验证了模型的有效性。而后开展大量数值仿真得到了不同工况下的炉内温度分布、各组分分布以及反应速率等关键信息。重点探究了硫铁矿焙烧工艺及颗粒尺寸对上述因素的影响,而后提出了增大底部进气速度、预热底部进气温度、减少冷排数量和减少冷排内水流量四种解决方案。数值模拟结果表明,通过上述方案,均可有效改善炉内温度失稳的问题,促进炉内硫铁矿的氧化反应速率,降低炉渣中的残硫率。最后,特别关注颗粒尺寸对硫铁矿焙烧工艺的影响,讨论了颗粒尺寸变化所能引起的安全隐患,提出了相应的解决方案,并进一步开展了更多的数值模拟工作,以证明所提出的想法的可行性。本研究的结果可为沸腾焙烧炉的生产工艺优化和炉内结构优化提供理论支持。
关键词:硫铁矿;多相流动反应;沸腾焙烧炉;数值模拟;残硫率
Numerical investigation on multi-phase reaction flow characteristics in pyrite fluidized roasters
Xiwen Mu, Hao Zhanga*, Xizhong An
Key Laboratory for Ecological Metallurgy of Multimetallic Mineral of Ministry of Education, School of Metallurgy, Northeastern University, Shenyang, 110819, PR China
As the first step in the sulfuric acid production process of pyrite roasting, the stable operation of the boiling roasting furnace is crucial to the entire process. Due to the long service life of most current boiling roasting furnaces, it is easy to encounter problems such as unstable temperature inside the furnace and high residual sulfur rate. In view of this, this study adopts a dual fluid method to numerically simulate the multiphase flow reaction characteristics of pyrite in a fluidized bed roaster. Firstly, the effectiveness of the model was verified by comparing it with on-site data and relevant literature results. Subsequently, a large number of numerical simulations were conducted to obtain key information such as temperature distribution, component distribution, and reaction rate in the furnace under different operating conditions. We focused on exploring the influence of pyrite roasting process and particle size on the above factors, and then proposed four solutions: increasing the bottom inlet velocity, preheating the bottom inlet temperature, reducing the number of cold discharges, and reducing the water flow rate inside the cold discharge. The numerical simulation results show that the above scheme can effectively improve the problem of temperature instability in the furnace, promote the oxidation reaction rate of pyrite in the furnace, and reduce the residual sulfur rate in the slag. Finally, special attention was paid to the impact of particle size on the roasting process of pyrite, and the safety hazards caused by changes in particle size were discussed. Corresponding solutions were proposed, and further numerical simulation work was carried out to demonstrate the feasibility of the proposed idea. The results of this study can provide theoretical support for the optimization of production process and internal structure of fluidized bed roaster.
Keywords: Pyrite; multiphase flow reactions; fluidized roaster; numerical simulation; residual sulfur rate
Biography: Xiwen Mu (1998- ), male, master student. Northeastern University, China. One journal papers published. Research interests: CFD, DEM, Multiphase flow, Process engineering.
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