Question

Carbonate ores are converted into oxides by

Answer 1

carbondioxide only ok

Answer 2

Carbonate ores are converted into oxides by a process called as Calcination.

Calcination is the process in which  a carbonate ore is heated strong in the absence of air to convert into metal oxide.

Example :

Zinc carbonate is heated in absence of air  to give zinc oxide.

ZnCO3(s) ------> ZnO (s)+CO2(g)