2K[Sb(OH)6] + 6HI Sb2O3 + 2I2 + 2KI + 9H2O
Potassium hexahydroxoantimonate(V) react with hydrogen iodide to produce antimony(III) oxide, iodine, potassium iodide and water. Hydrogen iodide - concentrated solution. The reaction takes place in a boiling solution.