铁矿山矿石破碎能量与粒度关系

Energy-size relationship of ore comminution in iron mine

摘要:

为研究铁矿石破碎能量与粒度的理论关系,将铁矿石从原矿破碎至精矿粒度的所有阶段看作一个破碎系统.首先对矿石破碎能量与粒度关系的基础理论进行整合分析,构建铁矿石破碎能量理论模型；然后通过现场调研的方法分析铁矿石破碎能量的变化特征,开展室内试验分析各破碎阶段铁矿石样品的粒度分布特征；最后采用数值拟合的方法分析铁矿石破碎系统单位能量随粒度的变化特征,使用矿山各破碎阶段的单位能量、矿石特征粒度和中值粒度验证铁矿石破碎能量理论模型的可靠性.研究结果表明,随着破碎阶段的变迁,铁矿山矿石破碎能量指数增加,且分布不合理,矿石粒度依次呈现指数函数分布、多项式函数分布和朗缪尔幂函数分布的特征,破碎系统单位能量与矿石粒度呈负相关的函数关系,在矿石中值粒度d₅₀为12 mm或特征粒度d₈₀为25 mm时,系统单位能量的变化速率出现转折.所构建的铁矿石破碎能量理论模型扩大了能量计算的粒度范围,可用于拟合铁矿石阶段破碎单位能量与入破粒度和产品粒度的函数公式,为铁矿山矿石破碎能量计算提供理论依据.

Abstract:

All the comminution stages of iron ore from raw ore size to the concentrate size were taken as one comminution system to research the theoretical relationship between comminution energy and particle size. Firstly, the basic theories of relationship between comminution energy and particle size of ore were analyzed to establish a theoretical model of comminution energy of iron ore. Secondly, the change patterns of comminution energy were analyzed in site investigation, and particle size distribution characteristics in each comminution stage were analyzed in indoor experiments. Lastly, the change patterns of specific energy of the comminution system were analyzed with the method of numerical fitting, and the reliability of the theoretical model of comminution energy was verified with the data of the specific energy, characteristic size, and medium size of the iron ore in each comminution stage. Results showed that the comminution energy of iron ore increased exponentially, the distribution of comminution energy was unreasonable, and the product granularity was characterized by exponential distribution, polynomial function distribution, and Langmuir power function distribution in turn along with the alteration of comminution stage in the system. There was a negative correlation function between the specific energy of the comminution system and the particle size of ore. The change rate of specific energy of the comminution system turned into a turning point when the medium size was 12 mm or the characteristic size was 25 mm. The established theoretical model of comminution energy has larger range of particle size in energy calculation compared with classical models. It can be used to fit the function formulas between specific energy of stage comminution and the size of feed and product and provides theoretical basis for the calculation of comminution energy in iron mine.