In part two of our series, we’re following manganese as it advances in the process and becomes a refined product.
Manganese Refining Process
After manganese ore is sent to the “mix house” where it is combined with other raw materials according to a special “recipe,” the mix is then added to a submerged arc electric furnace, where it is smelted. Smelting is the process of heating ore, causing it to react with other materials to remove impurities and extract a purer form of metal. Temperatures inside the furnace can reach a scorching 1,600 degrees!
After smelting, for Eramet Marietta’s ferromanganese product, the refining process continues. The molten metal undergoes an oxygen spargging process which helps to further purify the product.
Manganese Tapping
Once the manganese alloys have been smelted, and have reached the desired temperature, the furnace is “tapped” and the molten material flows from the furnace into a ladle.
Impurities rise to the top, which are then poured off into a series of cascading slag pots. The result of this tapping and pouring process is a purer manganese product. Once the product is sufficiently separated from the impurities or “slag,” it is poured into casting “beds” to mold into a workable shape.
Manganese Cooling and Stacking
In the final step of this phase, large slabs of manganese alloy are cast, cooled and transported to the Product Yard to continue cooling.