Powdered Slag
Ground slag, future mortar or fertilizer.
Ground Slag, one for one in a quern, and the mod's own phosphate fertilizer: 20 P and 5 K with a permanent 5 P boost, and it dissolves in water, so it goes straight on the soil rather than into a barrel. It is also half of a mortar batch. See Slag and its products for the rest of what slag makes.

Used in
Slaked lime 1L + Powdered Slag x 8 in a barrel: Mortar x 4
Needs: 1L Slaked lime, 8 Powdered Slag; makes 4 Mortar