Block similar to furnace but you can use FE/RF and fuels like coals with its custom recipe type you can make alloys

Made with

3 Blackstone 2 Redstone Dust 1 Blast Furnace 3 Iron Ingot

{
  "type": "corewithstuff:alloy_smelting",
  "ingredients": [
    {
      "item": "corewithstuff:celestial_cheese"
    },
    {
      "item": "minecraft:nether_star"
    }
  ],
  "result": {
    "count": 8,
    "item": "corewithstuff:space_block"
  },
  "craftTime": 200,
  "energy": 6000
}