Making Metal Ore and Chlorine Renewable: The Rust Maker

[JDL]

One of the best parts of Oxygen Not Included is building interesting resource loops that allow sustainable gameplay.

However, there are some resources that can be difficult to source renewably.

In particular, metal ore is unable to be made in renewable quantities without rocketry, This in turn prevents renewable use of the metal refinery, one of the best methods of making heat on demand without using geysers.

Another non-renewable resource without rocketry or geyser use is chlorine, as there are no renewable resource loops which produce this element, only consumers.

To allow renewable production of metal ore and chlorine, I'd suggest a possible new resource conversion machine: The Rust Maker.

At an operation cost of 480 W, the rust maker consumes 1,000 g of steel and 324 g of water per second, and produces 1,285 g of rust and 39 g of hydrogen per second.

This ratio is based on the molar mass of Fe2O3, the most common form of rust, and makes the building slightly power negative if recycling the hydrogen.

However, with this conversion, it's possible to recycle the rust via rust deoxidizer back into iron ore, chlorine gas and oxygen.

The interesting part of this cycle comes from the choices it enables, such as using the heat of a metal refinery producing steel with high temperature coolant to melt rust at 1:1 into iron, giving 1,285 g of iron for each 700 g used. Alternatively, via rust deoxidizer the iron is produced at a net relative mass loss, returning 685 g of iron for each 700 g used, but making useful byproducts in the process.

The conversion of steel to rust adds incentive for building both ore melting systems via high temperature transfer, as well as powered machinery to enable access to the byproducts.