11 O₂ + 4 FeS₂ → 8 SO₂ + 2 Fe₂O₃

This is an oxidation-reduction (redox) reaction:

FeS₂ is a reducing agent, O₂ is an oxidizing agent, FeS₂ is a reducing agent.

Reactants:

• O₂
  • Names: Dioxygen , Oxygen , Oxygen (liquefied) ... show moreO2 , O₂ , Oxygen gas , Molecular oxygen , Oxygen, refrigerated liquid , LOX , Liquid oxygen show less
  • Appearance: Odourless compressed gas ; Liquefied gas. colourless-to-blue extremely cold liquid
• FeS₂
  • Names: Ferrous disulfide , Fool's gold , Iron disulfide ... show moreIron persulfide , FeS2 show less

Products:

• SO₂ – Sulfur dioxide
  • Other names: Sulfurous anhydride , Sulphur dioxide , Sulfurous acid anhydride ... show moreSulfurous oxide , Sulfur oxide , Sulphur dioxide , sulfur dioxide , SO2 , R-764 show less
  • Appearance: Colorless gas ; Colourless gas or compressed liquefied gas with pungent odour ; Colorless gas with a characteristic, irritating, pungent odor. [Note: A liquid below 14°F. Shipped as a liquefied compressed gas.]
• Fe₂O₃ – Iron(III) oxide
  • Other names: Ferric oxide , Hematite , Ferric iron ... show moreRed iron oxide , Rouge , Maghemite , Colcothar , Iron sesquioxide , Rust , Ochre , Iron oxide dust and fume (as Fe) , Iron oxide red , Red oxide , Anhydrous ferric oxide , Iron (III) oxide , Diiron trioxide , Iron trioxide , Ferric sesquioxide , Iron(III) oxide [Iron oxide dust and fume (as Fe)] , Iron(III)oxide [Rouge] show less
  • Appearance: Red-brown solid ; Reddish brown-to-black crystals or powder ; Reddish-brown solid. [Note: Exposure to fume may occur during the arc-welding of iron.] ; A fine, red powder of ferric oxide. [Note: Usually used in cake form or impregnated in paper or cloth.]