Tailings

Tailings could not be found in Module:ItemData.

Tailings are pollution-causing blocks that are created when using the Screening Machine, Froth Floatation Cell, or Sensor Based Belt Sorter to create Concentrated Ores.

Tailings and Wet Tailings are similar items but are produced by different crafting tables.

Stockpiles and other storage (including vehicles) containing them will leak pollution into surrounding blocks. Only burying them under a significant amount of material will reduce them from polluting the surface.

Pollution Spread

If they are not stored correctly, they will pollute outward from their location. The pollution will spread in all directions and over time will increase the pollution level of the affected blocks.

Once they are moved or mitigated by burying, polluted blocks will take some time to recover back to normal.

They will continue to pollute at the same rate indefinitely, with no dropoff over time. There is no difference in the pollution emitted by them when stored in a stockpile or when placed outside of a stockpile.

Preventing Pollution

There is no way to totally prevent pollution. The amount of pollution caused by tailings can, however, be mitigated by burying them underground.

They must be buried under solid blocks (not rubble, such as Stone, for example). Dirt is the most economical choice, but almost any block can be used. The hole you bury them in does not need to be lined with any specific block, and can even be open underground as long as there are blocks above them.

Burial is the key to mitigating pollution. The deeper you bury the tailings from the surface block, the less leakage occurs. By 25-30 blocks below the surface, pollution leakage is small.

Specifics

They pollute ~50% less for every 5 blocks down you bury them. As in at a depth of 5 they will produce 50% of its pollution; at a depth of 10 it will produce 25%, and at 15 it will produce 12.5%. Going on infinitely until it approaches zero pollution, but technically it will always release some amount of pollution. [1]

The surface/top block is where it begins the depth calculation before reaching the tailings. If you placed a single block 1000 meters in the air above a tailing, it would effectively be buried at a depth of 1000 meters. That's partially why giant towers of tailings end up not polluting as much as you think they will - that and the height differences make pollution spread slower. [2]

Storing in vehicles

While it is possible to store in vehicles, they will emit pollution as if they were not mitigated at all, even if the vehicles are buried. They must be taken out of the vehicle inventory and buried in Stockpiles or individually on the ground.

Crafting

Crafting Recipes

Crafting Station	Item				Materials				Level Needed	Crafting Time (mins)	Labour Cost	XP Gained
Screening Machine	Iron Concentrate x1		Tailings x1		Crushed Iron Ore x3				Mining Level 1	1.2	120	1
Sensor Based Belt Sorter	Iron Concentrate x2		Tailings x1		Crushed Iron Ore x5				Mining Level 1	0.4	150	1

Used in Recipes

None

History

Changes
9.0.0 Beta	Slag was introduced and replaced Tailings at certain Crafting Tables like the Bloomery. Wet Tailings was introduced as another way to process Ores.