The dry closed circuit ball mill circuits of Tata Steel’s pelletizing plant in IJmuiden receive a variable mixture of ores to produce a dry ground iron ore mixture. A population balance model was developed to help study circuit unit performance, the impact of installation modifications and influence of input materials on the performance of the circuits. Batch grinding tests were done on input materials, measuring size distribution as function of time using high resolution laser diffraction measurements. Data from the tests were fitted to a breakage and selection function model as well as a cumulative rate model. A population mass balance model of the circuit was developed based on the breakage and selection function model, as it showed a better fit to the batch data for the majority of materials. The circuit model also incorporates a mill model and model for the various classifier stages. The circuits were sampled at various locations in the flow sheet, showing fair overall agreement with model calculations. Differences between model and observations are highlighted and improvements in the modelling technique as well as the sampling discussed.

中文翻译：

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艾默伊登球团厂铁矿石干磨的群体平衡模型验证


塔塔钢铁公司位于艾默伊登的球团厂的干式闭式球磨机回路接收各种矿石混合物，以生产干磨铁矿石混合物。开发了一个总体平衡模型来帮助研究电路单元性能、安装修改的影响以及输入材料对电路性能的影响。对输入材料进行批量研磨测试，使用高分辨率激光衍射测量测量尺寸分布随时间的变化。将测试数据拟合到破损和选择函数模型以及累积率模型。基于破损和选择函数模型开发了电路的总体质量平衡模型，因为它显示出与大多数材料的批次数据更好的拟合。电路模型还包含磨坊模型和各个分类器阶段的模型。电路在流程图中的不同位置进行了采样，显示出与模型计算的总体一致性。重点介绍了模型和观测值之间的差异，并讨论了建模技术和采样的改进。