Suggestion: Steel
Use: as a replacement for refined iron in higher-level creations, such as an ADV. Circuit, ADV. Machine, etc. also, possibly a replacement for iron/refined iron in IC tools, such as the mining drill.
recipe: 2 Iron dust + 1 coal dust (shapeless?) yields 2 steel dust. smelting provides a steel bar, 4 steel bars in a square make a steel block, for easy construction once you have a steady supply.