Unloading Consumer Goods
It is possible to transform raw metal into "consumer goods"--things like cell phones and flat-panel televisions--as you unload the metal onto a world.
The "consumer goods" unloaded in this way disappear--they are snapped up by an eager population. It is no longer metal, and cannot be used again. The main reason to do this is to attempt to win back converts, those unfortunate members of your population who have fallen under the influence of an enemy Missionary.
Each consumer good unloaded has a 50% chance of un-converting one convert, so it is most practical to use this technique while there are still relatively few converts at a world.
If you are a Trader, you also gain points for unloading consumer goods, whether or not there are converts at a world.