Your smelters are full of cadmium. Right now it goes up the chimney.
Fume scrubbers pull that metal-bearing dust out of the air around your furnaces and boilers into filters, and clean up a little pollution while they're at it. Wash the loaded filters for cadmium, plate steel parts with it, and you get cheaper engines, and the hardware your rockets and nuclear reactors need. The dirtier the air around a scrubber, the faster it works, so the smokiest corner of your factory becomes your best cadmium mine.
It starts after sulfur processing. There are no ore patches to find: put scrubbers among your furnaces and boilers, keep them supplied with filters, and wash what comes back.
Factorio 2.1 only. Space Age is optional.
What it adds
- Fume scrubbers, with red and green science. A scrubber turns a filter (steel and coal) into a loaded filter every 240 seconds and removes a little pollution while it runs.
- Filter washing in a chemical plant with sulfuric acid: one cadmium sponge per filter, and the filter comes back 80% of the time. Smelt the sponge into cadmium plates.
- Cadmium-plated hardware: one plate, one steel and a little acid make four.
- Engine with plated bearings: 2 steel, 2 gears, 2 pipes and 1 hardware make 3 engines, about a third less iron per engine. The ordinary engine recipe stays.
- Rocket parts need plated hardware: two per part without Space Age, one with it.
- Rails with plated fasteners: twice the rails per steel and iron stick. The ordinary rail recipe stays.
- Flying robot frames need one plated hardware; roboports, steam turbines, centrifuges and Space Age's big mining drill need a few. Only buildings whose research already comes after sulfur processing are charged.
- Nuclear reactors need 50 neutron absorber assemblies, each made from 2 cadmium plates and 1 steel. Fusion reactors (Space Age, Krastorio 2) need 50 too, Krastorio 2's nuclear locomotive 10, and portable fission reactors (and Space Exploration's portable fusion reactor) 5.
- Electrostatic precipitators, with blue science: a 4×4 scrubber with three times the throughput and four times the pollution removal.
- Impregnated filters, with purple science: treated filters that scrub twice as hard and yield one or two sponge per wash.
Fume bands
With pollution enabled, a scrubber works faster the dirtier its chunk is. The chunk's pollution is shared among all scrubbers in it. Below 50 per scrubber they run at base speed; from 50, 150 and 400 they gain +50%, +100% and +150% speed, and use that much more power. Alt-mode shows the bonus above each scrubber.
With pollution disabled, scrubbers simply run at base speed, so cadmium production works in every game.
Early scrubbers barely dent pollution: on steam power, their own electricity cancels most of what they remove. Real cleanup needs precipitators, impregnated filters and clean power.
Space Age
Only Nauvis has airborne pollution, so scrubbers switch themselves off on the other planets and cannot be placed on space platforms. The other planets have their own sources:
- Vulcanus: acid neutralisation with cadmium recovery. It neutralises twice the acid for twice the steam, takes 50% more calcite, and has a 5% chance of cadmium sponge per batch. Unlocked with calcite processing.
- Fulgora: scrap leaching. 20 scrap and sulfuric acid give one sponge plus some iron and copper. Unlocked with recycling.
- Gleba and Aquilo import plated hardware. It weighs 1 kg, so one rocket carries 1,000.
Other mods
| Mod | What changes |
|---|---|
| Tellurium | Optional filter washes use a little more acid and recover tellurium residue now and then; the ordinary washes keep working. When Tellurium puts tellurium metal into solar panels (and K2 advanced solar panels), Cadmium replaces that ingredient with cadmium telluride, made from one cadmium plate and one tellurium metal. |
| Krastorio 2 | Fume scrubbers and electrostatic precipitators are available as usual. K2's own air purifier stays K2's pollution cleaner, and its used filters can be leached with sulfuric acid for cadmium. With Brass Tacks, zinc enrichment gets an optional cadmium-recovery variant. |
| Space Exploration | Cargo rocket sections need plated hardware, and cadmium sponge, plates and hardware fit the delivery cannon. With Tellurium, gamma-ray detectors and night vision need cadmium zinc telluride crystals. |
| Brass Tacks | Zinc purification: refine zinc in a chemical plant with sulfuric acid and recover cadmium — the richest source, about four scrubbers' worth per plant. Ordinary smelting stays. |
| Magnesium | Magnesia can replace coal in scrubber filters, a third more filters per steel. |
| Phosphorus | Phosphate rock carries cadmium: a phosphorus furnace recipe that also collects cadmium-rich dust, washed into cadmium sponge. Filters can also be washed with phosphoric acid instead of sulfuric acid. |
| Gallium | Loaded filters can be washed for arsenic instead of cadmium: one arsenic oxide per filter, two per impregnated filter, and the filter comes back as often as usual. Brass Tacks zinc purification now and then leaves mineral residue for gallium. With Tellurium and Space Exploration, gamma-ray detectors and night vision take a gallium detector assembly in place of the crystal: the same crystal with gallium arsenide readout. |
| Neodymium | The fume scrubber gets an optional magnet recipe. With If Nickel, nickel-metal-hydride batteries use lanthanum instead of cadmium. |
| Caesium | Caesium's well treatment station is built with cadmium-plated hardware. |
| Antimony | Cadmium-plated hardware goes into Antimony's shoreline coolant outlets when available at the thermal workshop's research tier. |
| If Nickel | Nickel-cadmium batteries: nickel and cadmium instead of lead, zinc, graphite and acid. The ordinary recipe stays. |
Getting started
Research Fume scrubbing after sulfur processing. Build a few scrubbers in your smelting and boiler area, feed them filters and take out the loaded ones. Wash those in a chemical plant, send the returned filters back and smelt the sponge.
At base speed a fume scrubber makes one sponge every four minutes, so plan on a small group rather than a single machine: about 15 keep 45 chemical science per minute supplied when every engine uses plated bearings. Then research Cadmium plating. The research for robots, roboports, steam turbines, centrifuges, the rocket silo and nuclear power requires it. Adding Cadmium to an existing save? Robot frames and rocket parts need plated hardware from then on; the FAQ explains how to ease in.
Startup settings let you change how much pollution scrubbers remove, or leave individual recipes unmodified. Map settings control the fume bands.
For recipes, numbers and settings, see the FAQ tab.
Credits
Cadmium is by fluffy_penguin. Thank you to the artists whose work it uses:
- Fume scrubber building and icons: Hurricane046, from Hurricane Graphics (MIT © 2023 Nicholas Gower). The precipitator is the same building, tinted and scaled up.
- Scrubber filter icons: Byzzee, from Better Ecology (MIT).
- Cadmium sponge icon: MrSmoothieHuman1, from Periodic Madness (MIT).
- Activated carbon badge on the impregnated filters: tirisabella, Johanna Spieker and _traum, from Sosciencity Graphics (CC BY 4.0). The badge is layered over the tinted filter icons; the image itself is unchanged.
The thumbnail is original. The cadmium plate, plated hardware, neutron absorber and cadmium telluride icons were made with image-generation tools. Cadmium's code and original artwork use the MIT license; the credited artwork keeps its own license, and the full texts ship in THIRD-PARTY-NOTICES.txt inside the mod. Factorio assets remain Wube's.