Manganese(II) sulfate Manganese(II) sulfate Manganese(II) sulfate usually refers to the inorganic compound with the formula MnSO·HO. This pale pink deliquescent solid is a commercially significant manganese(II) salt. Approximately 260 thousand tonnes of manganese(II) sulfate were produced worldwide in 2005. It is the precursor to manganese metal and many other chemical compounds. Mn-deficient soil is remediated with this salt. Like many metal sulfates, manganese sulfate forms a variety of hydrates: monohydrate, tetrahydrate, pentahydrate, and heptahydrate. The monohydrate is most common. All of these salts dissolve to give faintly pink solutions of the aquo complex [Mn(HO)]. The pale pink colour of Mn(II) salts is
Manganese ferromanganese (usually about 80% manganese) is the intermediate in modern processes. Small amounts of manganese improve the workability of steel at high temperatures by forming a high-melting sulfide and preventing the formation of a liquid iron sulfide at the grain boundaries. If the manganese content reaches 4%, the embrittlement of the steel becomes a dominant feature. The embrittlement decreases at higher manganese concentrations and reaches an acceptable level at 8%. Steel containing 8 to 15% of manganese has a high tensile strength of up to 863 MPa. Steel with 12% manganese was discovered in 1882 by Robert Hadfield and is