Electrolytic manganese is a pure form of the metallic element manganese, Mn. It is termed “electrolytic” because a major step in the refining process involves electrolysis, a chemical reaction driven by an electric current. Less pure forms, such as ferromanganese and silicomanganese, are derived by more economical methods. The pure metal is primarily used as an alloy in the production of stainless steel and aluminum. Electrolytic manganese is also used extensively as an element in lithium-ion batteries designed for electric vehicles.
The initial stages of manganese processing involve heating the ore and using chemical treatments to remove the majority of impurities. Electrolysis is then used to further refine the metal. A solution of the material is placed in an electrolytic cell and a direct electrical current is passed through. The direct current induces a chemical reaction that separates the manganese from naturally occurring contaminants.
Electricity enters the cell through the anode, a negative electrode, and exits through the cathode, a positive electrode. Passing a direct current through the manganese solution can cause either oxidation, a loss of electrons, or reduction, a gain in electrons. This results in electrolytic manganese metal (EMM) collecting on the positive cathode and electrolytic manganese dioxide (EMD) collecting on the negative anode. The electrodes are removed periodically and the manganese deposits collected in the form of flakes. Heating the flakes to 925°F (500°C) removes latent hydrogen and results in a manganese powder with purity in excess of 99.9%.