Phosphorus

Requires Factorio 2.1.23 or later in the 2.1 series.

Phosphorus

The element that punishes buffers.

White phosphorus ignites in air. Leave it waiting for 15 minutes, in a chest, on a belt, in a train or in your pocket, and it bursts into flame: the chest takes the damage, fire spreads to every stack of white phosphorus nearby, and all that's left is ash. Your usual answer to everything, a bigger buffer, is now a fire hazard.

Initially you have three choices:

• Use it right away. Plastic, lubricant, processing units and batteries all need phosphorus. Build the furnace next to the consumer and keep the belt short.
• Burn the surplus. The combustion tower burns white phosphorus into heat for your heat pipes and leaves ash, which you dissolve into phosphoric acid, pour into concrete or ship to Gleba as fertilizer.
• Make it safe. Convert it to red phosphorus in a kiln running on the tower's heat, wash it, and ship it anywhere. Red phosphorus never ignites. A retort turns it back into white right where you need it, with two slots for speed or efficiency modules.

Every one of these costs something, and working out which one each part of your base should use is the puzzle.

Later, production and utility science unlock powered preservation cabinets and two research lines: stronger phosphorus weapons and safer buildings. Space-science protection eventually cuts building damage by 99%, while preserving the spoilage and logistics problem.

Requires Space Age to be owned (for the spoiling feature), not enabled. Plays in vanilla, with Space Age, and with Brevven-style material packs up to Krastorio 2 and Space Exploration.

What you build

• Phosphorus furnace: phosphate rock, coal and stone into white phosphorus (coke, graphite electrodes and silica with material mods). Phosphate rock is a new violet ore, found away from your starting area.
• Combustion tower: burns white phosphorus into 2 MW of heat and ash. White phosphorus in its fuel slot is safe. Idle towers cool by 1 °C per second toward 15 °C; connected heat storage keeps them warm longer.
• Conversion kiln: turns white into crude red phosphorus in batches of 50, heated by the tower next to it. Reachable Magnesium supplies its lining; Antimony supplies drive bearing material.
• Phosphorus retort: turns red back into white next to the consumer. Two module slots accept speed and efficiency modules; ten red still yields nine white. Its own small red/green research follows Phosphorus processing and eligible Tellurium processing. Construction uses condenser metal and pipes, with magnesia lining and tellurium copper where available. Existing saves retain earned retort access.
• Glow marker: an unpowered green lamp that burns for 24 hours, dims, and leaves a little ash. Point at it to see how long it has left.
• Preservation cabinet: late 2×2 storage for white phosphorus only, with one input slot, one output slot and a separate ash-removal slot. Five items become five fresh items in five seconds, retaining quality. It keeps stored contents fresh for 250 kW continuously and one water per second while occupied. Power loss, water loss or circuit disablement resumes ageing. Moving water, bubbles and status lights show whether it is working.

The fire

• Without late protection research, a burning full stack destroys an iron chest. Inherent fire resistance helps, but only up to 50 %; walls keep theirs, so walls and gaps make firebreaks.
• Fire jumps to white phosphorus in neighbouring inventories, a few hops at most. Wooden buildings burn better.
• In vacuum, on thin-air worlds and under water there is no fire. It still turns to ash.
• Nothing destroys white phosphorus for free: other mods' incinerators, crushers and recyclers can't take it.
• Too harsh? The time before it ignites is a startup setting, from 2 to 120 minutes.
• Late building protection reduces the remaining phosphorus damage by 25%, 50%, then 75%. Space-science tiers reach 90%, 95%, then 99%; the final finite tier costs 20,000 of each required science pack. Contents still spoil and fire can still spread. Vehicles, characters, trains and robots do not receive building protection.
• Late weapon research gives 20%, 40%, then 60% extra phosphorus burn damage against hostile forces; infinite space-science research adds 20 percentage points per level. Accidental and friendly burns stay unchanged.

What needs it

Plastic, lubricant, processing units (doped silicon), batteries (phosphoric acid), and heat pipes and heat exchangers (red phosphorus). Each can be switched off in the startup settings.

Explosives manufacturing requires one phosphorus ash per four explosives. The normal vanilla batch makes four explosives from two coal, two sulfur, 20 water and one ash in eight seconds. Supply ash from a combustion tower. The former ash-dried alternative is removed; existing plants migrate to the normal recipe. This change has its own startup setting and recipe bypass.

Land mines also need one red phosphorus per four mines for primer components, retaining their other ingredients, crafting time per mine and combat effects. Research stays at the existing science tier. This use has its own startup setting and recipe bypass.

The rewards are optional: red phosphorus primers for more ammunition, incendiary magazines, grenades and flamethrower ammo, doped advanced circuits, etched processing units, phosphate concrete, landfill from ash, fertilized Gleba nutrients, and uranium from phosphoric acid.

Planet mods