Potassium permanganate is one of the best known manganese products. It is a powerful oxidising agent with bactericidal and algicidal properties, which enable it to be used in purifying drinking water and treating waste water. It is also used for odour control, including deodorisation of discharges from paint factories, fish-processing plants, etc. Permanganate has a variety of other applications as an oxidant.

Ferrite components
Photo by THOMSON-CSF/LCC
Jacques Pierre

An important application for manganese is “Maneb” (manganese-ethylene bisdithiocarbamate), an organo-chemical compound sold in the form of a yellow powder. It is sold under different trade names as an agricultural fungicide and is widely used for controlling crop and cereal diseases, downy mildew in vines, scab in fruit trees, banana and peanut diseases among others. Some 200 000 tons of Maneb is estimated as a world-wide consumption figure.

An organic manganese compound known as MMT (methylcyclopentadienyl manganese tricarbonyl) is used on a small scale as an octane booster or anti-knock agent in gasoline. MMT can dramatically improve oil combustion, reducing boiler clogging and soot levels. This application is important from an environmental point of view as it allows lead to be replaced, but it has not yet been fully developed. There are numerous other applications of manganese oxide and salts. Manganese dioxide is used as a catalyst in the production of artificial flavours like vanilla. It is also used as an oxidising agent in treating uranium ore to produce the oxide-concentrate known as “yellow cake”. Other applications include the colouring of bricks and tiles, driers and as a pigment for paints, etc.

Manganese sulphate is widely used as an end product in fertilisers and animal feed, and as an intermediate product in the chemical industry. Manganese phosphatation is used to produce surface films which, when sealed with oil or wax, can protect steels for internal or outdoor uses (when conditions are less severe). Manganese phosphating improves wear resistance, prevents welding of metals under load, increases lubrication efficiency by oil absorption and assures rapid and safe running-in of moving parts.

Another important material is manganese ferrite, a soft ferrite widely used in electronics. Large amounts are consumed in the manufacture of television circuit boards. Manganese for this purpose can come from ore, oxides, carbonates and even metallic manganese. Manganese is used in the process of making electrolytic zinc. In Mn0₂ form it is used to purify the leach solution by oxidising the iron; as MnS0₄ it can be added to the electrolyte to reduce corrosion of the lead anode. By forming a light coating on the cathode, it also facilitates stripping of the zinc deposit.

A novel application under development is that of manganese organo-metallics : they provide an intermediate step in the synthesis of fine organic chemicals of high added value.