Abstract
One of the biggest challenges facing mineral processing plants is the high variability in mined ore properties such as hardness, particle size, and composition. Technology to measure these properties online is still limited. Even when imperfect measurements exist (e.g. online particle size or grade analysers), not all operations have the flexibility to mix, divert or blend ore streams to try to reduce the variations. However, when this is the case, the question arises, what strategies exist to control and smooth variations in a way that reduces the impact on the processing plant and how should these be evaluated? In this paper, I highlight two fundamental methods of dealing with disturbances—buKer tanks and ratio control—and draw attention to the existing academic literature on these topics, which provides valuable insights on the selection and design of ore blending and smoothing systems. Using numerical simulations, I illustrate the main properties, benefits, and limitations of each. The simulations also reveal how system design, physical constraints, and measurement inaccuracy limit the ability to reject or attenuate disturbances in ore properties.