Authors:
I. Nolet, J. Nell
International FerroAlloys Conference, Helsinki, Finland, June 6 - 9, 2010
Abstract
A typical Manganese Oxygen Refining (MOR) process involves the injection of inert gases through bottom tuyeres and top lance injection of oxygen to de-carburise a charge of HC FeMn, containing about 7%C, down to a carbon content of 1.5-2%C. The melt temperature typically needs to be controlled below 1750oC to protect vessel refractories, and to minimise Mn losses to the gas phase. Fluxes can be added to adjust slag chemistry. In order to study optimal process conditions, a dynamic model of this process, incorporating kinetic and thermodynamic aspects, has been developed using Metsim™. Non-ideal solution models have been incorporated for the metal and slag phases. The bubble interface is modelled using a Free Energy Minimiser (FEM) to which a metal and slag flow is directed, thereby controlling mass transfer between the reaction site and each of the bulk phases. Logic controllers have been included to modify top and bottom blowing rates based on blowing time and trigger/stop material additions based on totalising instruments and time of the cycle. The main input values and other tuning parameters can be readily modified by the user via a user-friendly Excel interface handling the simulation input and results. A large number of usercreated objects facilitate model input management from the interface. Examples are presented to demonstrate the model behaviour for changes in process conditions such as metal fines addition, slag chemistry and top blowing rate.
