How does an electrolytic cell deposit pure manganese on a cathode?

To produce pure manganese through electrolysis, manganese ores are first roasted to create an MnO calcine, which is then dissolved in sulfuric acid to produce a manganous sulfate solution. This solution undergoes a purification process where impurities such as iron, aluminum, arsenic, copper, zinc, lead, cobalt, and molybdenum are precipitated out using ammonia and hydrogen sulfide.1

Once purified, the solution is fed into the cathode portion of an electrolytic cell. When an electric current is passed through the cell, manganese is deposited in layers onto a stainless-steel cathode sheet. These cathode sheets are extracted periodically, and the accumulated manganese deposits are removed by hammering. Finally, the resulting flakes are heated to 500 °C (925 °F) to remove hydrogen, yielding a product with a purity greater than 99.9 percent.1