1 furnace + 2 coal + 2 iron + 4 brick blocks -> 1 fusion furnace.

Fusion furnaces take the same fuel that vanilla furnaces do, but cook slower (600 ticks per operation, rather than 200), so they consume more fuel.

Fusion furnace recipes have the general form of:

              [catalyst]
                  V  
    [input1]->[output]<-[input2]

               [fuel]

For example, the steel nugget & chunk recipes:

coal/charcoal + iron + coal/charcoal(C) => steel nugget
coal/charcoal + iron + gunpowder(C) => medium steel chunk
coal/charcoal + iron + redstone(C) => large steel chunk

Shorthand representation for the above recipes would be:

coals + iron ingot + coals/gunpowder/redstone (S/M/L) => steel nugget/medium chunk/large chunk.
or just:
coals + iron ingot + coals/gunpowder/redstone (C) => steel (S/M/L).

• Steel: coals + iron ingot + coals/gunpowder/redstone (C) => steel (S/M/L)
• Bronze: copper ingot + tin ingot + bone meal/gunpowder/redstone dust(C) => bronze (S/M/L)
• Thyrium: mythril ingot + adamantium ingot + redstone dust/lapis lazuli/glowstone dust(C) => thyrium (S/M/L)
• Sinisite: mythril ingot + onyx gem + glowstone dust/blaze powder/ghast tear(C) => sinisite (S/M/L)
• Fusion Recycling

Large chunks can be smelted like raw metal to form metal ingots. (Unlike raw metal, you cannot make storage blocks out of them, yet.) Nuggets and medium chunks have to be crafted together into large chunks; they cannot be smelted.

2 medium chunks + 1 nugget -> 1 large chunk 5 nuggets + 1 medium chunk -> 1 large chunk 1 large chunk -> 2 medium chunks (yes, this is a lossy conversion; intentionally so) 4 nuggets -> 1 medium chunk 9 nuggets -> 1 ingot (as per vanilla).

• Top: inserts into catalyst slot
• Bottom: extracts from output slot
• Back, Front: inserts into fuel slot.
• Left: inserts into left input slot
• Right: inserts into right input slot