S-H2S-SO3-H2SO4-CuSO4-Cu(OH)2

S+H2-->H2S2H2S+3O2-->2H2O+2SO2 , 2SO2+O2-->2SO3SO3+H2O-->H2SO4H2SO4+CuCL2-->CuSO4+2HCLCuSO4+2NaOH-->Cu(OH)2+Na2SO4