How does silicon reduce manganous oxide in low-carbon ferromanganese production?

In the production of low-carbon ferromanganese, silicon acts as a chemical reducing agent to convert manganous oxide (MnO) into manganese metal. The process involves fusing manganese ore, lime flux, and coal to create a melt rich in MnO, which is then brought into contact with silicomanganese or low-carbon silicomanganese.1

During this reaction, the silicon present in the alloy reduces the MnO to manganese metal, while the silicon itself is oxidized and transferred into the slag. The carbon content of the final ferromanganese product is determined by the specific silicomanganese agent used; for instance, using standard silicomanganese typically results in about 1 percent carbon, whereas using low-carbon silicomanganese can reduce the carbon content to approximately 0.1 percent. This method is essential because, while higher manganese oxides can be reduced by carbon monoxide, the reduction of MnO to metal typically requires higher temperatures and specific chemical interactions to achieve the desired low-carbon and low-silicon specifications.12