Developing a stepwise approach to simulate a hammer mill through the Whiten model - the adherence for a gold ore

Abstract Comminution represents a large portion of the capital and operating cost of a mineral processing plant. In 1983, Cohen estimated that comminution processes could account for 30% to 50% of the power consumption of the mill, and typically represents 50% of the operating costs of a mine. Therefore, its optimization is directly related to reduction of these operating costs. Among the crushing equipment, the hammer mill is one which is dedicated to operations that aim for a high reduction ratio with the controlled generation of fines. This crusher is recommended for friable and low abrasive ores presenting a high productive capacity. This study aims to develop a stepwise approach that allows the use of the classical crusher model (Whiten-Andersen) in modeling and simulation of circuits containing a hammer mill, simulating the resulting product according to variation of rotation speed within the equipment. The existing model for crushers developed by Whiten-Andersen considers the Perfect Mixing Model, which represents crushing through equations related to selection and breakage functions, that provide an equilibrium condition. This study aims to develop a stepwise approach that allows the use of the classical crusher model in modeling and simulation of circuits containing a hammer mill, by simulating the effect that the variation of rotation speed within the equipment implies in the generated product. The comparisons between the experimental and simulated data indicated that the model fits the data for both, P80 values and percentage passing in 19.1 mm sieve. The model created was validated based on specific experimental campaign.

摘要 矿石粉碎工序在选矿厂的基建与运营成本中占比极高。1983年，Cohen经估算指出，破碎磨矿流程的能耗可占选矿厂总能耗的30%~50%，且通常占矿山运营总成本的50%。因此，对该工序的优化可直接实现上述运营成本的削减。在各类破碎设备中，锤式破碎机（hammer mill）是专为实现高破碎比且可控生成细粒级产物的作业设计的设备，适用于易碎、低磨蚀性且产能较高的矿石。本研究旨在开发一套分步式方法，以实现在包含锤式破碎机的破碎流程建模与仿真中应用经典破碎机模型——怀滕-安德森（Whiten-Andersen）模型，并基于设备转速的变化对最终产物进行模拟。怀滕-安德森开发的现有破碎机模型以完全混合模型（Perfect Mixing Model）为基础，通过与选择破碎函数（selection and breakage functions）相关的方程描述破碎过程，该类函数可满足平衡条件。本研究通过模拟设备转速变化对生成产物的影响，实现将经典破碎机模型应用于含锤式破碎机的破碎流程建模与仿真。实验数据与仿真结果的对比表明，该模型对P80（P80）值以及19.1 mm筛的过筛率均具有良好的拟合效果。本研究所构建的模型已通过针对性试验批次完成验证。