My two miners in Dwarf Fortress dropped their pickaxes

Couple of options:

  1. Assign two other dwarves the mining labor, they should go grab the picks. If so, then something has happened to your miners - perhaps they're injured somehow?

  2. Make sure the picks are forbidden/marked for dumping or smelting or something.

  3. Make sure the miners didn't get activated as soldiers with kits that prevent picks.

As a final option you can try building a weapons stockpile and get the picks moved there - if they don't go, then something is preventing dwarves from interacting with the picks themselves.