Lava is reported as a contained heat source for a small slag test.

Direct answer

The frozen evidence reports lava as a heat-stage component.

The community post describes putting lava inside a filter and letting slag pass over the top so the slag cooks automatically. A developer reply calls that setup an autoburner, but the complete machine behavior remains version-sensitive.

Processing use

Separate the heat zone from the rest of the line.

1. Contain lava inside the filter area described by the discussion.
2. Send a small slag batch over the heat zone.
3. Keep a visible route for processed output and a separate route for unprocessed material.
4. Use a recirculation check only after observing the current build's result.

Community report

The reported behavior includes a narrow planter interaction.

The same discussion contains a later player note about a planter box above the lava box. That observation is COMMUNITY evidence and does not establish a general lava, plant, or combustion system.

Evidence boundary

No exact temperature, ratio, or permanent recipe is claimed.

This is a COMMUNITY-guided layout test. Confirm current build behavior before routing a production line through lava or treating a screenshot as a complete blueprint.