Reactivity
Highly reactive with oxygen, water vapor and acids due to its pure metallic shape.
It reacts slowly with cold water, but violently with hot water or steam:
Mn+2H2O→Mn(OH)2+H2↑
Oxidation states
Common oxidation states are +2, +4, +6 and +7.
In EMM, manganese is mostly in the 0 oxidation state (metallic form).
Reaction with acids
Readily soluble in dilute sulfuric acid (H2SO4) or hydrochloric acid (HCl):
Mn+H2SO4→MnSO4+H2↑
Forms flammable hydrogen gas (requires ventilation).
Oxidation in the air
At room temperature, it forms a protective oxide layer (MnO2) that prevents further oxidation.
When heated in air, it burns in a powdered state, forming manganese oxides:
3Mn+2O2ΔMn3O4
Redox behavior
A strong reducing agent in acidic/alkaline environments (e.g., reduces NO3- to NH3).
Formation of alloys
It combines with iron, aluminum, and copper to form corrosion-resistant alloys (e.g., stainless steel).
Catalytic activity
It acts as a catalyst in organic synthesis and hydrogenation reactions.
Effects on cleanliness
High purity (≥99.7%) minimizes unwanted adverse reactions in industrial processes.
Basic safety instructions:
Flammability: Fine powder is an explosion hazard; keep away from sparks/open flames.
Corrosiveness: Reacts with moisture to release hydrogen gas (ensure dry storage).
Industrial significance:
Stability in alloy matrices increases the steel's resistance to oxidation and sulfideation.
It is necessary for the synthesis of manganese-based chemicals (e.g., KMnO4, MnO2 for batteries).
These properties make EMM indispensable in metallurgy, chemical manufacturing, and energy storage technologies.
