>>2338
Metals dissolve into one another very easily. If everything is molten, there's basically no energy barrier to prevent atoms from moving through the mixture freely. Because it's hot, the atoms move fast, so because of thermodynamics they form an equal mixture.
Below 1000 kg, you can basically just throw in the ingots, keep it above the highest possible melting point for 10 seconds and have a homogeneous distribution.
If you're below the highest melting point, you need to wait for the solid lumps to dissolve in the liquid. If you try to make bronze but are below the melting point of copper, using copper shavings would indeed make waiting shorter.