How is potassium dichromate prepared from chromite are ?

Explanation

(1) Chromite ore is heated with sodium carbonate in excess of air to form sodium chromate.
`4FeCr_(2)O_(4)+8Na_(2)Co_(3)+7O_(2)to8Na_(2)CrO_(4)+2Fe_(2)O_(3) +8C0_(2)`
(2) Sodium chromate is filtered and acidified with sulphuric acid to give sodium dichromate.
`2Na_(2)CrO_(4)+H_(2)SO_(4)toNa_(2)Cr_(2)O_(7)+Na_(2)SO_(4)+H_(2)O`
(3) Sodium dichromate is treated with KCl to form potassium dichromate.
`Na_(2)Cr_(2)0_(7)+2KCIKtoCr_(2)O_(7)+2NaCI`