What can be done with Tin/Copper/Molybdenum ingots?
Once you've smelted the metal rock to make plain metal ingots, and converted that plain metal, into one of the actual metal ingots (tin/copper/molybdenum) using the alchemical tongs: what can be done with it now? Make tools? But how?!
Apparently sell it for great amounts of currants.
Um, but yeah - there was no instructions or quest related with that, so I don't even know if it's been fully implemented yet.
Soon enough, they will be requirements in certain kinds of projects. And you'll be able to make tools with them. And, later, they will be base inputs in to Future Technologies.