Metal Volcano

Metal Volcanoes are geysers that erupt molten metal at very high temperatures. They are one of the most useful renewable resource sources in the game, but also one of the most dangerous to tame because they inject both matter and heat into the surrounding area. Most Metal Volcanoes follow the standard geyser cycle of dormant, active, and idle phases, with the ejection phase occurring during the active period.

The main challenge is heat management. During the ejection phase, hot metal must be captured in a buffer that can absorb the thermal load without overheating. During the idle phase, that stored heat must be moved away so the setup is ready for the next eruption. The dormant phase provides downtime, but it should not be relied on as the only cooling window. For most Metal Volcanoes, the erupting material is easier to cool while it is still liquid than after it becomes debris, so enclosing the volcano and handling the output as a liquid stream is usually the most effective approach.

A common high-efficiency solution is to use a water or steam buffer with a Steam Turbine. Under ideal conditions, a self-cooled Steam Turbine can delete 292.53 kDTU/s of heat. The amount of water needed depends on the metal’s eruption temperature, freezing point, and specific heat capacity, so there is no single universal design that works perfectly for every metal volcano. In practice, the required buffer size is based on how much heat must be removed before the metal solidifies and how much heat the chosen buffer medium can absorb before leaving its safe temperature range.

• For gold, iron, and aluminum volcanoes, the average output over the active period is a better sizing reference than lifetime average output, since the eruption burst can easily overwhelm underbuilt cooling.
• The output rates of metal volcanoes are generally in the 200–400 kg/cycle range, while Niobium Volcanoes are much larger, producing about 800–1600 kg/cycle.
• Niobium Volcanoes are a special case: they erupt huge quantities of very hot liquid Niobium and can quickly entomb themselves in solid Niobium if handled like other metal volcanoes. They require a different taming strategy.

In the early game, Sand can be dumped into a Metal Volcano as a low-tech way to produce Glass and refined metal. Sand has a higher heat capacity than Granite and Sandstone, but lower than Igneous Rock, and its melting point is also higher than those common raw minerals. If the Sand melts, it becomes Liquid Glass, which can later cool into Glass debris and be collected. When the hot metal transfers heat to the Sand, it solidifies into Refined Metal, which can then be moved into a storage bin submerged in liquid to finish cooling.

This method can be surprisingly efficient: adding small amounts of Sand every few eruptions can produce Glass at a 1:1 ratio, which is far better than a Glass Forge’s 4:1 ratio and does not require a large power setup. If Glass is not needed, dumping a large amount of Sand can be a simple long-term solution, especially if the volcano is sealed with Insulated Tile and placed in a vacuum room so heat does not spread into the rest of the base. An Auto-Sweeper can then collect the cooled Refined Metal automatically.