\(\left(1\right)2Al_2O_3\xrightarrow[Na_3AlF_6]{đpnc}4Al+3O_2\uparrow\)
\(\left(2\right)2Al+3H_2SO_4--->Al_2\left(SO_4\right)_3+3H_2\uparrow\)
\(\left(3\right)Al_2\left(SO_4\right)_3+3BaCl_2--->3BaSO_4\downarrow+2AlCl_3\)
\(\left(4\right)AlCl_3+3NaOH--->Al\left(OH\right)_3\downarrow+3NaCl\)