Furnaces

Furnaces are the containers used to turn ores into ingots. Cooking food requires a stove, creating low tiered ingots requires a cobblestone furnace, creating medium tiered ingots requires a steel furnace, and the highest tiered ingots are crafted with a osmium furnace.

New furnaces
As you read above, there are four different kinds of furnaces. The regular one, which is a cobblestone furnace, is used to smelt ingots up to and including silver. The cobblestone furnace has three input slots, one heating slot and one output slot.



The steel furnace is required to smelt hardened steel and better. The furnace has five input slots, three heating slots and one output slot.

The osmium furnace is required to smelt mithril and better. This furnace has ten input slots, five heating slots and one output slot.

The stove is used to cook all kinds of food and green dye. This furnace is the same as the vanilla furnace.

Multiple heating slots
Because of the heat required to smelt five ores at the same time, steel furnaces have three heating slots. The amount of time there's a fire in the furnace is the average burning time from all the materials in the heating slots. That means if you were to put one coal in each of the slots, the fire would be able to smelt 8 ingots.

$$\text{Total ingots to smelt} = ((s^{1} + s^{2} + s^{3}) / s)$$

where sn is how many ingots the material in the slot can smelt and s is amount of slots.

The osmium furnace has five heating slots. Smelting high tiered ores requires infernostone. Infernostone in the osmium furnace will only smelt one ingot.