K->KOH->Al(OH3)->Al2(OH)3->Al2(SO4)3->Al->Al2O3
K + H2O = KOH 3KOH + AL(NO3)3 = 3KNO3 + AL(OH)3↓ AL(OH)3 + Na2SO4 = AL(SO4)3 + NAOH AL(SO4)3 + 3Сu = 3CuSO4 + AL 2AL + 3O = AL2O3