Modelling of gas-solid reactions - Usage of industrial off-gas for pre-reduction of manganese ores

Abstract

The traditional way of making manganese alloys are by reduction of different manganese oxides, iron oxides and silicon dioxide in a standalone electric furnace. That being said, manganese alloy producing companies may consider the implementation of a prereduction unit which will pre-reduce the ore before entering the electric furnace reducing the overall electrical consumption per ton alloy produced. How well the prereduction unit will contribute to the reduction of electrical consumption have previously been found to rely heavily on ore content. At this point, we should implement a reliable model which describes the process at hand inside a theoretical pretreatment unit.

An established framework describing the gaseous reduction of manganese oxide inside a prereduction unit has been made which relies on a continuous model taking the most important gas-solid reaction related phenomena into account. The model proved to be both fast and resilient. Several relevant cases were tested on the implemented continuous model to see how it performed. Some flaws were found. These were related to heat transfer and different kinetic parameters such as rate constants. There still exists some industrially relevant questions that go unanswered concerning prereduction. Here, our model can be used to assist further work and decisions on the matter.