Naming first, because it breaks every old guide: what the demo called Slag, Burnt Slag and the Kinetic Slag Press is now Residue, Burnt Residue and the Kinetic Press. Same pipeline, new labels — if you searched "sandustry slag", this is the page.
Residue is the guaranteed byproduct of sifting: every Wet Sand through a Shaker leaves one, which is why it piles up about four times faster than your gold. The instinct to treat it as garbage is exactly wrong — processed fully, the residue line is your second income stream and the source of every Seed your farm will ever plant.
Step one: the burn (a 25% affair)
Burnt Residue comes from setting Residue on fire, and the odds are official: each Residue has a 25% chance to become Burnt Residue; the rest simply burns away. Roughly 4 residue in, 1 burnt residue out. Fire sources, in unlock order:
- Flamethrower (400 Gold) — manual, fine for the first hours.
- Burner Belt (Tier 2, 500 Gold) — a conveyor that ignites its cargo, heated by a Thermal Buffer.
- Pyro Dispenser (Tier 3, 2000 Gold) — fires a flame burst every 3 seconds, also Thermal-Buffer-fed.
- The lava trap — the classic free automation: trap Cinder inside a Filter with a solid block beneath, ignite it once into permanently captive Lava, and belt your residue across it (the lava guide covers sourcing the cinder). No fuel, no power, runs forever.
One more wiki note: a sufficiently large ignited pile keeps burning on its own as long as you keep feeding it — the crude version works before any of the machines do.
Step two: the press (a 25-block drop)
The Kinetic Press (500 Gold) converts Burnt Residue deterministically — 1 Gold + 1 Seed each — but only if the input arrives with enough kinetic energy: it must fall at least 25 blocks before hitting the press. Short drops don't convert; the material just sits on top and blocks the machine. Two build rules follow:
- Build the press at the bottom of a tall shaft. The 25-block fall is the machine's real footprint; the press itself is the small part.
- Unclog with angled Launchers. The wiki's own fix for slow-drop pileups is launchers mounted along the press tops, flicking stalled material back up into the shaft.
Output falls through the press's underside: gold to your Collector, Seeds onward to the farm.
Why the line is worth it
Count the yield of 8 residue: the burn leaves ~2 burnt residue, the press turns those into 2 gold and 2 seeds, and each seed planted is a flower worth another gold plus 4 Amethelis. The "waste" stream from 8 sifted sands ends up worth roughly as much as the sifting itself paid — which is exactly why the community's compact factory designs (see blueprints) run the shaker staircase and the press shaft as one continuous machine.