Ore becomes ingots, ingots become alloys. There are three furnaces for that, and every alloy needs a specific mix at a specific temperature and pressure. Here is how it fits together – with the values from the game.
Three furnaces
| Furnace | Base draw | What it does |
|---|---|---|
| Furnace | 5 W | basic metals and alloys, 1,000 litre chamber |
| Advanced Furnace | 100 W | also all super alloys, with built-in gas intake and output in litres per tick |
| Arc Furnace | 5 W | basic metals and charcoal only, with electricity instead of fuel – a fixed time and energy per ingot |
The arc furnace is the easiest start: ore in, press Activate, ingot out. It has no gas output – whatever gas the ore releases ends up in the air around it. Values per ingot from the game data:
| Ingot | Time | Energy |
|---|---|---|
| Ingot (Iron) | 1 s | 200 J |
| Ingot (Copper) | 3 s | 500 J |
| Ingot (Silicon) | 3 s | 100 J |
| Ingot (Lead) | 5 s | 1,000 J |
| Ingot (Nickel) | 5 s | 1,000 J |
| Ingot (Silver) | 5 s | 1,000 J |
| Ingot (Gold) | 6 s | 2,000 J |
For alloys you need the furnace or the advanced furnace.
The window of temperature and pressure
In a gas furnace the ore melts as soon as the chamber is at least as hot as its flash point – metal ores from 373.15 K (100 °C), coal from 323.15 K, ice from 273.15 K. The contents collect inside. An ingot forms when three things match:
- the mix of contents is right,
- the temperature is inside the window,
- the pressure is inside the window.
On top of that the mould has to be open (Open = 1) – before that no ingot comes out. Every unit of mix makes one ingot: 30 iron and 10 carbon become 40 steel ingots. Only for the super alloys does one ingot take 4 units.
For basic metals the window is generous: from a minimum temperature and from 100 kPa, open upwards. Ingot (Iron) needs at least 800 K, lead only 400 K. Alloys are stricter:
- Steel: 75 % iron and 25 % carbon (or hydrocarbon from Ore (Coal)), from 900 K and from 1,000 kPa.
- Solder: iron and lead half and half, only between 350 and 550 K, from 1,000 kPa. Too hot is a real problem here.
- Invar: iron and nickel half and half, 1,200–1,500 K and 18,000–20,000 kPa.
- Electrum: gold and silver half and half, from 600 K, 800–2,400 kPa.
- Constantan: copper and nickel half and half, from 1,000 K and from 20,000 kPa.
The chart shows all windows side by side. Temperature on the left, pressure on the right (logarithmic):
The super alloys (Astroloy, Hastelloy, Inconel, Stellite, Waspaloy) are only made in the advanced furnace. Their pressure windows are high: Waspaloy, for example, needs at least 50,000 kPa – close to the gas pipe limit of 60,795 kPa.
Example: steel
Steel is the first alloy almost everyone needs. The recipe in detail:
How to do it:
- Keep the mould closed (
Open= 0). - Put iron ore and coal into the furnace at a ratio of 3 : 1.
- Bring the furnace up to at least 900 K using its gas.
- Keep the pressure inside at 1,000 kPa or more.
- Once everything has melted and temperature and pressure fit, open the mould. Now the steel ingots come out.
Why open it only at the end? With the mould open, the furnace checks every tick whether the contents fit a recipe. While only the iron has melted, the recipe for iron ingots fits – and those come out instead of steel. If the contents fit no recipe at all, it ejects them as slag.
Gases from the ore
Ores release gas when they melt. One piece of Ore (Iron), for example, releases 0.5 mol of carbon dioxide and 2 mol of pollutant. Over many ores that adds up – the furnace needs a gas outlet, otherwise the pressure keeps rising. What each ore releases is shown on its page under “Material, fire and recycling”.
Watching the furnace with IC10
Furnace and advanced furnace expose Temperature and Pressure as logic values. The other values mean:
| Value | Meaning |
|---|---|
Open | mould: 1 = open, ingots or slag come out |
Activate | ignition button: a 5 J spark into the chamber, melts one piece of ice from the import slot; drops back to 0 after 0.1 s |
RecipeHash | hash of the ingot the contents would currently make, otherwise 0 |
Mode | 1 when a recipe currently fits – but only refreshed while the game is rendering the furnace, never on a dedicated server |
Setting | basic furnace: no effect; advanced furnace: the same as SettingOutput |
SettingInput, SettingOutput | advanced furnace only: litres per tick drawn from the input pipe or pushed into the output |
For a chip, RecipeHash is therefore the better choice than Mode. How to address devices by name is explained in IC10: control a device by name.
Further reading
- All windows and mixes: Furnaces and alloys
- Work out a furnace charge for an alloy: Furnace calculator
- Fuel and combustion: Gases