The development of a simulative hybrid model for optimising the production of a high-carbon ferromanganese furnace.

[摘要] ENGLISH ABSTRACT: A project was initially commenced for optimising the production output at a specifichigh-carbon ferromanganese furnace. Since operational difficulties were experiencedin this furnace and with a lack of reliable data for the year 2007, it was decided thatdata from a more stable high-carbon ferromanganese furnace should be analysedinstead. Three key performance indicators (KPI's) were selected to give an indicationof overall process performance. These were: (1) the total tonnes of high-carbonferromanganese produced per tonne of feed material, (2) the percentage recovery ofmanganese to the alloy product, and (3) the alloy:slag ratio. Maximisation of each ofthese would contribute to the overall improvement of the process.To achieve the objectives of the project, a hybrid model was developed to characterisethe production behaviour of the furnace and to optimise the proposed KPI's. Thehybrid model consisted of two modelling branches, viz. equilibrium and dynamicmodelling. An equilibrium sub-model was created and the output results were thenused as inputs into a dynamic sub-model, which not only considered the effects ofthermo-equilibrium interactions, but also the faster-changing electrical dynamics offurnace control. The final modelling step involved genetic optimisation, wherebymodel variables were manipulated to optimise the proposed KPI's. In other words,operating conditions were established to improve furnace performance.It was determined that significant improvement in the values of the KPI's may beexpected if the optimised setpoints are implemented on-site. The existing setpoints forelectrical operation should be maintained while the power expended per tonne of alloyshould be altered (by tapping more regularly). Specific adjustments to the proportionsof the feed recipe should also be made.

[发布机构] Stellenbosch University