Ferromanganese is a high-carbon ferro alloy with a high manganese concentration that is processed in the FERRO MANGANESE PLANT. Ferromanganese may contain up to 80 percent manganese by weight. It is produced by heating a combination of the oxides Manganese dioxide and Iron III oxide, together with carbon, whether in a blast furnace or a submerged arc furnace-type system. In the furnaces, the oxides undergo carbo thermal reduction, yielding ferromanganese. Steel is treated with ferromanganese as a de-oxidizer. In addition to all this, ferro manganese is mostly used to mitigate the negative effects of sulphur.