Optimization of a pellet plant process parameters using six sigma methodology
CIM Montreal 2011
Andrea McGlynn, Joël Fortin, Sheryl Morris,
With a rising demand for iron ore, most pellet plants are looking to increase throughput. Optimization studies can be of use but difficulties arise due to the many variables and interactions involved, compounded by multiple pellet types. This can be overcome using six sigma methodology, a systematic analysis that identifies easy gains to increase production capacity and reduce operating costs. Using this strategy, it was determined that there was a potential capacity increase of roughly 15% in the filtering and balling area at IOCC (Iron Ore Company of Canada, Labrador City).
First, a capacity study was done to determine the possible gains. Then, a screening DOE (Design of Experiment) was performed with several variables, to evaluate the importance of each and identify interactions. Finally, an optimization DOE quantified the impact of the factors. The results show that recommended operating conditions of temperature and pressure are dependent on the pellet type. For SA pellets, a higher temperature reduced additive consumption by 5-10%. For DR pellets, a higher density and lower temperature increased throughput by 1-6%.
This methodology can be applied to other areas of the plant. It allows us to better understand the process and, therefore, it is useful for process control, expert system or future expansion plans.