硫化矿石动态自热率测定装置及其数值模拟

Reaction Device for Measuring the Dynamic Spontaneous Heating Rate of Oxidation for Sulfide Ore Sample and Its Numerical Simulation

针对已有研究中硫化矿石自热特性测定方法的不足,设计了一种适用于用圆柱坐标一维导热方程和有关边界条件及初始条件就可以计算硫化矿石矿样的动态氧化自热速率的测定装置。该测定装置的主体为耐高温石英玻璃特殊反应器。反应器的长度远大于其直径,矿样的上下都有绝热层;通过分析反应器的排气口气体成分确定需要的氧气流量,以保证氧气供需平衡;供给的氧气经过预热,不会由于氧气温度低于矿样温度而吸收一部分矿样的氧化热。利用有限元分析软件ANSYS得出反应器内部硫化矿样各点在不同时刻的温度场分布,实现了温度场可视化三维输出。通过改变矿样参数,得出矿样不同松散系数时的温度变化,并比较了其自热的难易程度。模拟结果表明,将有限元分析技术与硫化矿样自热模拟实验相结合,实现温度场动态模拟的方法是可行的;克服了实验条件单一、周期长等不足,通过改变矿样参数进行多次计算,达到优化实验参数的目的。

As the existing methods for measuring self-heating characteristics of sulfide ores suffer from some drawbacks, this paper proposes an experimental device and method, which combines with cylindrical coordinate one dimensional heat conduction equation, relevant boundary and initial conditions, to determine the dynamic spontaneous heating rate of oxidation for sulfide ore samples. The main body of the device is a special quartz glass reactor of high temperature resistance. The length of reactor is much longer than that of its diameter; with heat insulating layers on both bottom and top of ores. The oxygen flow is determined by analyzing the gas compositions in exhaust port to keep an equilibrium between supply and consumption of oxygen. The supplied oxygen is preheated, so it will not absorb some oxidation heat of ores. By ANSYS software, the inner temperature field of ores in the reactor at different instants can be calculated, with a visualized three dimensional output of temperature. By varying the material properties of ores, temperature fields of two ore samples were obtained, and their liabilities of self-heating were compared. The results show it is practical to combine ANSYS analysis with the experiment of spontaneous heating for sulfide ore sample to simulate dynamic temperature field. By this method, some shortcomings such as lack of variability, time consuming and high cost of experiment can be overcome, and the experimental parameters can be optimized through varying the parameters and several repeated calculations.