FexOy + KHSO4 + KNO3

6FexOy + aKHSO4 + (6x – 4y)KNO3 —> 3xFe2(SO4)3 + bK2SO4 + (6x – 4y)NO + H2O
2FexOy —> 2xFe+3 + 2yO-2 + (6x – 4y)e
N+5 + 3e —> NO
Theo K: a + 6x – 4y = 2b
Theo S: a = 9x + b
—> b = 15x – 4y và a = 24x – 4y
6FexOy + (24x – 4y)KHSO4 + (6x – 4y)KNO3 —> 3xFe2(SO4)3 + (15x – 4y)K2SO4 + (6x – 4y)NO + (12x – 2y)H2O