What Is Manganese Sulfide?
Manganese sulfide is a compound of manganese and sulfur.
It occurs in minerals such as alabandite and rambergit. Manganese sulfide is generally found in the monosulfide or disulfide state. In addition, Manganese Sulfide (II) has three transformations: α, β, and γ.
A similar name is manganese sulfate, but it is a completely different compound with or without oxygen.
Uses of Manganese Sulfide
Manganese sulfide is mainly used as an additive to improve the machinability of sintered parts in the field of powder metallurgy.
Powder metallurgy is a manufacturing process in which metal powders are formed and sintered to produce metal products. Small motor parts for washing machines, fans, hard disks, etc. are examples of products processed by this powder metallurgy process.
Properties of Manganese Sulfide
- Manganese Sulfide (II) Alpha Form
It is a green cubic crystal. Its melting point is 1,620℃ and it is antiferromagnetic. - Manganese Sulfide (II) Beta Form
Red cubic crystal - Manganese Sulfide (II) Gamma Form
Pale red cubic crystal. p-type semiconductor at 700℃.
Among manganese sulfide (II), β- and γ-forms are unstable. The β and γ forms are unstable in manganous manganese sulfide (II) and are quickly oxidized to the α form. When used in powder metallurgy, the stable α-form is used.
Manganese sulfide (IV), on the other hand, is a blackish-brown cubic crystal. It is anti-ferromagnetic.
Structure of Manganese Sulfide
Manganese sulfide (II) has the chemical formula MnS and a molecular weight of 87.00. The alpha form of manganese sulfide (II) has a sodium chloride type structure with a Mn-S distance of 0.261 nm and a density of 4.05 g/cm3.
The beta form of Manganese Sulfide (II) has a zinc shear zinc ore type structure with a Mn-S distance of 0.243 nm and a density of 3.27 g/cm3.
Manganese sulfide (II) has a wurtzite-type structure with a Mn-S distance of 0.241 nm and a density of 3.26 g/cm3.
On the other hand, manganese sulfide (IV) has the chemical formula MnS2, with a molecular weight of 119.07. It has a pyrite-type structure. Its density is 3.463 g/cm3, Mn-S distance is 0.259 nm, and S-S distance is 0.209 nm.
Other Information on Manganese Sulfide
1. How Manganese Sulfide (II) Is Produced
Manganese sulfide (II) is also called manganese monosulfide. The alpha form of manganese sulfide (II) occurs naturally as sphalerite. Manganese sphalerite is a mineral that contains cubic manganese (II) sulfide.
Sphalerite is also called manganite sulfide or arabite. The alpha form of Manganese Sulfide (II) can be obtained by boiling an aqueous solution of manganese (II) chloride in the presence of a small amount of potassium oxalate, adding a slight excess of ammonia water, and passing hydrogen sulfide through it. The beta form of manganese sulfide (II) can be formed by passing hydrogen sulfide through an aqueous solution of manganese (II) acetate when cold.
The gamma form of manganese sulfide (II) can be obtained as a precipitate by boiling an aqueous solution of manganese chloride (II), adding ammonium chloride, and passing hydrogen sulfide through the solution while adding ammonia water.
2. Method of Producing Manganese Sulfide (Iv)
Manganese sulfide (IV) is also called manganese disulfide. It occurs naturally as a hauerite. Manganese sulfide (IV) can be obtained by adding sulfur and potassium polysulfide to an aqueous solution of manganese (II) sulfate and heating in a sealed tube.
When heated, manganese sulfide (IV) decomposes to release sulfur. Manganese sulfide (IV) reacts with hydrochloric acid to form manganese chloride (II).