Cadmium FAQ

What does Cadmium add?

Fume scrubbers that capture metal-bearing dust into filters, a washing step that recovers cadmium from them, and cadmium-plated hardware for engines, rockets and nuclear reactors. Scrubbers work faster in polluted chunks and remove some pollution while they run. There is no cadmium ore: it all comes from the air around your factory, or from the planet-specific sources in Space Age. Factorio 2.1 is required; Space Age is optional.

What are the recipes?

These are the base recipes before quality. Acid quantities are fluid units. Scrubbing times are at crafting speed 1.

Removal is at base speed with plain filters. Impregnated filters double it without using more power.

Cadmium has four core technologies. Fume scrubbing (red and green, after sulfur processing) unlocks scrubbers, filters, washing and plates. Cadmium plating (red and green, after engines) unlocks plated hardware and the engine recipe; the rail recipe unlocks with Railway. Electrostatic precipitation needs blue science and Impregnated filters purple. With Krastorio 2, Purifier filter leaching is added, and with If Nickel, Nickel-cadmium batteries.

How do fume bands work?

Every few seconds Cadmium reads the pollution of each chunk that contains scrubbers and divides it by the number of scrubbers in that chunk. That share sets each scrubber's band:

Sponge output, pollution removal and power use rise together. A scrubber keeps its band until the share drops below 85% of the threshold, so a scrubber that cleans its own chunk does not flicker between bands. Alt-mode shows the current bonus above each scrubber.

Crowding many scrubbers into one chunk splits its fumes between them. Spread them over the dirty chunks around your furnaces and boilers instead. Speed from your own beacons adds to the fume bonus.

The Fume band threshold multiplier map setting scales the 50, 150 and 400 thresholds. Faster scrubbing in polluted areas turns the bands off; scrubbers then always run at base speed.

Does Cadmium work with pollution turned off?

Yes. Scrubbers run at base speed and cadmium production works normally; there is no fume bonus and nothing to clean. A fume scrubber then makes one sponge every four minutes. For 45 chemical science per minute, with every engine using plated bearings, plan on about 15 fume scrubbers or 5 precipitators, or 4 precipitators with impregnated filters.

Do scrubbers really clean the air?

A little early on, noticeably later. A fume scrubber removes 2 pollution per minute at base speed, but on steam power its own 90 kW emits 1.5 of that back, so it keeps a quarter. A precipitator on steam keeps about half, and three quarters with impregnated filters. On solar or other clean power, scrubbers keep all of it: 20 precipitators at +50% remove 240 pollution per minute, about a sixth of what a 45 SPM base emits.

Treat the first scrubbers as a cadmium source rather than a pollution fix. The washing chemical plants add a little pollution of their own. The Scrubber pollution removal startup setting scales removal; at 0, scrubbers are a pure cadmium source.

Why do scrubbers stop on Vulcanus, Fulgora, Aquilo and Gleba?

Scrubbers capture airborne pollution, and only Nauvis has it. Vulcanus, Fulgora and Aquilo have no airborne pollutant, and Gleba's is spores. On those planets a scrubber shows "No airborne pollution on this surface" and stops. Scrubbers cannot be placed on space platforms.

The other planets get their own sources:

• Vulcanus: acid neutralisation with cadmium recovery neutralises twice the acid for twice the steam, takes 50% more calcite, and has a 5% chance of one cadmium sponge per batch. It is unlocked alongside the ordinary acid neutralisation, with calcite processing.
• Fulgora: scrap leaching in a chemical plant turns 20 scrap and 40 sulfuric acid into 1 sponge, 2 iron plates and 1 copper plate in 4 seconds. It works only on Fulgora and is unlocked with Recycling.
• Gleba and Aquilo import plated hardware. It weighs 1 kg, so one rocket carries 1,000.

Neither planet recipe accepts productivity.

Which vanilla recipes change?

• Rocket part: +2 plated hardware without Space Age (200 per rocket), +1 with Space Age or Space Exploration.
• Flying robot frame: +1 plated hardware.
• Roboport +5, steam turbine +5, centrifuge +10 and (Space Age) big mining drill +10 plated hardware.
• Nuclear reactor: +50 neutron absorber assemblies; portable fission reactor +5. The assembly unlocks with the research of whichever of these comes first.
• Fusion reactor (Space Age, Krastorio 2) +50, nuclear locomotive (Krastorio 2) +10 and portable fusion reactor (Space Exploration) +5 neutron absorber assemblies.
• The research that unlocks each of these requires Cadmium plating.
• Engine unit and rail: unchanged. The plated recipes are alternatives: engines use about a third less iron, rails twice as many per steel and iron stick.

Building charges only apply where the building's research already comes after sulfur processing, so Cadmium never delays early machines such as trains. Other ingredients are preserved. Each change can be bypassed; see below.

What happens with Krastorio 2?

Cadmium plays the same way as without K2, including the 4×4 electrostatic precipitator and the same research. K2's own air purifier stays K2's pollution cleaner, and Cadmium does not change it. Purifier filter leaching (after K2's air purification and Fume scrubbing) washes a used pollution filter with 25 sulfuric acid into 3 cadmium sponge, returning the filter 80% of the time; K2's own biomass restore recipe stays.

With Brass Tacks as well, zinc enrichment with cadmium recovery is an optional variant of K2's enrichment: 2 more sulfuric acid and a 2.5% chance of cadmium sponge per zinc ore. The ordinary enrichment is unchanged.

How does Cadmium work with Tellurium?

Tellurium is optional. When it is installed:

• Each filter wash gets a variant with tellurium recovery. It uses 10 more sulfuric acid and adds a 10% chance of one tellurium residue. The ordinary washes stay, so the byproduct is your choice. The plain variant unlocks with Fume scrubbing, the impregnated one with Impregnated filters.
• When your Tellurium version puts one tellurium metal into each batch of solar panels, Cadmium replaces it with cadmium telluride: one cadmium plate and one tellurium metal, crafted in 4 seconds. The panels still carry just one charge. Solar energy research then requires Fume scrubbing. With Tellurium 0.2.1 and Krastorio 2 the same swap applies to advanced solar panels (1 per 4 panels).

The recovery washes are a supplement, not a replacement for Tellurium's own recovery. A fume scrubber at base speed yields about 0.025 residue per minute, 13% of one Tellurium copper recovery plant. A precipitator at +150% matches one plant.

What about Space Exploration and Brevven's mods?

Space Exploration: every cargo rocket section needs 2 plated hardware and satellites' rocket parts need 1 each. Cadmium sponge, plates and hardware can be shipped by delivery cannon. Scrubbers work on planets and moons with airborne pollution. With Tellurium installed too, each gamma-ray detector and each night vision equipment needs one detector crystal — cadmium zinc telluride (1 cadmium + 1 zinc + 1 tellurium → 2) where Brass Tacks zinc exists, cadmium telluride (1 cadmium + 1 tellurium → 1) otherwise — unlocked with the gamma-ray telescope or night vision.

Brass Tacks: zinc purification is the richest cadmium source. It refines zinc in a chemical plant with sulfuric acid — as fast per building as a steel furnace, never faster — and recovers one sponge per 40 zinc ore, about four fume scrubbers' worth per plant. Ordinary zinc smelting keeps working; the recipe unlocks with Fume scrubbing. Under Krastorio 2 it keeps K2's zinc yield.

If Nickel: nickel-cadmium batteries make 4 batteries from 2 nickel, 1 cadmium plate, 4 iron and 40 water — no lead, zinc, graphite or acid. The ordinary battery recipe stays. Research Nickel-cadmium batteries after Fume scrubbing and Battery.

What does Cadmium cost in UPS?

Very little. Scrubbers are ordinary crafting machines; each has a hidden beacon that carries its fume bonus. A small script checks a few chunks every 12 ticks, visiting every chunk with scrubbers about every five seconds. In a benchmark with 1,000 fume scrubbers, four per chunk in 250 polluted chunks, the script averaged 0.019 ms per tick, with a 99th percentile of 0.26 ms and a maximum of 0.32 ms (Factorio 2.1.20).

Can I add Cadmium to an existing save?

Yes. No map regeneration is needed because no resources are placed. When you load the save, research you have already completed unlocks its Cadmium recipes.

From then on, rocket parts, flying robot frames, roboports, steam turbines, centrifuges, big mining drills, nuclear and fusion reactors and portable reactors need plated parts or absorbers (cargo rocket sections too with Space Exploration, and gamma-ray detectors and night vision need detector crystals with Space Exploration and Tellurium). Robot frame and rocket part production stops until you have plated hardware, so research Fume scrubbing and Cadmium plating and build a few scrubbers soon after adding the mod, or list those recipes under unmodified recipes until you are ready. Back up your save first.

Can I remove Cadmium?

Yes, but back up your save first. Factorio removes Cadmium's buildings, items and recipes from the save, including filters and hardware in chests and the hidden beacons behind the fume bonus. The recipes Cadmium charged go back to their ordinary ingredients. Pollution the scrubbers were removing is no longer absorbed.

Can I bypass a recipe change?

Use the Unmodified recipes startup setting, with comma-separated internal recipe names. It accepts:

• Host recipes Cadmium changes: rocket-part, flying-robot-frame, roboport, steam-turbine, centrifuge, big-mining-drill, nuclear-reactor, fission-reactor-equipment, fusion-reactor, kr-fusion-reactor, kr-nuclear-locomotive, se-fusion-reactor-equipment, se-cargo-rocket-section, and with Tellurium solar-panel, kr-advanced-solar-panel, se-gammaray-detector and night-vision-equipment.
• Cadmium's alternatives: cadmium-engine-unit, cadmium-rail, cadmium-acid-neutralisation, cadmium-scrap-leaching, cadmium-zinc-purification, cadmium-enriched-zinc, cadmium-nickel-battery, cadmium-filter-washing-tellurium and cadmium-impregnated-filter-washing-tellurium.

A bypassed host recipe keeps its ingredients, and its research does not gain a Cadmium prerequisite. A bypassed alternative is not added. Log Cadmium changes writes every recipe and research change to the Factorio log.

What do the other settings do?

• Scrubber pollution removal (startup, 0–4, default 1): multiplies how much pollution scrubbers remove. At 0 they are a pure cadmium source.
• Faster scrubbing in polluted areas (map, default on): turns the fume bands on or off.
• Fume band threshold multiplier (map, 0.1–10, default 1): scales the pollution needed per scrubber for each band.