### Clue: Working men in rage smelt this (4,3)
### Answer: IRON ORE 
 ### Explanation: Definition: smelt this
 [ ON(working, as with an electrical appliance, say) + OR(abbrev. for "other ranks", non-commissioned men in the military) ] **contained in**(in) IRE(rage;anger).
Defn: The "this" that goes through smelting to retrieve pure metal.