Sandustry

Sandustry Slag and Lava Processing Chains

Turn the constant stream of slag from your shakers into steady extra gold and spores. Build a trapped-lava auto-burner, filter only Burnt Slag into a height drop, and feed Kinetic Slag Presses without clogging.

Burnt Slag → Gold + Spore Lava auto-burner 25+ block drop

The core goal

Convert slag into gold and spores automatically

Shakers processing wet sand produce a constant stream of slag as a byproduct. The goal is to convert that slag into Burnt Slag automatically using trapped lava, then drop only Burnt Slag from sufficient height into Kinetic Slag Presses (unlocked via Refining 2). Each successful Burnt Slag hit yields 1 Gold + 1 Spore. The two failure modes are manual flamethrower grind and press clogs.

Step 1

Trap lava for a semi-permanent heat source

Moving and storing raw lava is the hardest part. The community workaround is to freeze lava into a solid, transport the solid, then re-melt it inside a trapped chamber.
1Freeze natural lava pools with snow, ice, or a Cryoblaster. The lava becomes Scoria.
2Destroy the Scoria with any tool or weapon. It becomes Cinder, a solid powder that belts, launchers, filters, and grabbers handle cleanly.
3Transport the Cinder to your factory. Belts or launchers work fine since Cinder behaves like normal powder.
4Build a shallow bucket chamber one block deep with a solid bottom where you want the lava to live.
5Place Filters set to allow only Cinder over the chamber, then drop Cinder in.
6Ignite the Cinder with a Flamethrower. It converts back to lava that stays trapped in the bucket. Passive heat sources usually do not re-melt Cinder, so use the flamethrower for this step.
Overfill the bucket slightly. Players report trapped lava lasts a long time at moderate slag rates, so you do not need to top it up constantly.

Step 2

Build the slag auto-burner over the lava

1Route slag from your shakers on belts or launchers into a burn hall positioned over the trapped-lava filters.
2Keep the space above the lava filter low, one to two blocks tall in compact designs, so slag particles pass close to the lava flames and sparks.
3Add a wall or row of Filters set to allow only Burnt Slag. Filters work sideways too, so lava sparks pass through to ignite incoming slag while burnt slag continues onward.
4Add a recirculation path at the end of the burn line. Any uncooked slag that slips through gets looped back instead of reaching the presses and jamming them.
5For higher volume, layer burner sections with burnt-slag-only filters between them. Burnt slag moves out while unburnt stays exposed longer.
Burning is not 100% efficient. Community tests put conversion around 20-25%, with the rest consumed. Continuous flow plus recirculation is what keeps output steady. Manual flamethrower or rocket napalm works early but does not scale.

Step 3

Feed only Burnt Slag into the Kinetic Slag Presses

Kinetic Slag Presses require Burnt Slag dropped from height (commonly cited 25+ blocks). Side-feeding or low drops just pile material on top and block everything. One successful Burnt Slag hit produces 1 Gold + 1 Spore.
1Filter strictly: only Burnt Slag into the drop shaft or chute. Raw slag, sand, water, or anything else either wastes the hit or clogs.
2Control the flow. Use a two-block-high conveyor or spread particles with launchers or a staircase so they lose horizontal speed and fall one at a time. Multiple particles landing during the process window fail and start clogs.
3Keep the underside clear. Gold and Spores must fall out freely. If the output pile reaches the press bottom, new hits stop. No water or lava under the press.
4Place angled Launchers along the top of the press row aimed sideways. They clear stagnant pixels that land on top without interrupting successful falling ones.
5Add extra vertical space or slow the feed if spores back up. Spores are the most common output bottleneck.

Full chain

The complete layout players use

Shaker bank (diagonal) → slag belt → lava burn trench + filters → Burnt Slag-only filter → height drop (≥25 blocks, controlled flow) → Kinetic Slag Press row → Gold collectors + Spore overflow
Keep the whole wing away from moss, flowers, and plant areas. Stray embers from the burner will destroy farms.

Key decisions

Choices to make before you build

Manual or auto burn?

Manual flamethrower or rocket napalm is fine early at low volume. Switch to lava traps as soon as you can move Cinder. Players call continuous manual flamethrower work frustrating and it does not scale.

Recirculate unburnt slag?

Always recirculate if possible. Without recirculation, unburnt slag reaches the presses and jams them, killing throughput.

Single tall drop or multiple presses?

Spread across several presses with launchers for high volume. One tall shaft works for compact builds but backs up faster under load.

How big a Cinder stockpile?

Overfill the lava bucket a bit. Trapped lava lasts longer than expected at moderate slag rates, so a larger stockpile means less frequent refills.

Common pitfalls

Mistakes to avoid

XFeeding raw slag or mixed material into presses. Instant clog. Filter strictly to Burnt Slag only.
XInsufficient drop height or dumping a whole column at once. Use 25+ blocks and meter the flow so particles fall one at a time.
XLetting output, especially spores, pile up under the press. Once the output pile reaches the press bottom, new hits stop.
XPutting liquids under the press or letting steam rain into the hall. Water and lava under the press break the drop. Steam condensation contaminates the chain.
XNo recirculation. Unburnt slag that slips past the burner reaches the presses and jams them.
XBuilding the burner too close to plant areas. Stray embers destroy moss, flowers, and farms. Keep the wing isolated.
XForgetting Filters work sideways. Sideways filters can let sparks through while sorting, which is useful, but misconfigured ones can also let the wrong material through.