First level of my hause is made of those "slagblock". And yes, it was created specificaly to remove some od ash created in coal powerplants (at least in Poland).

Good idea.

That's an interesting idea, AI

Looks interesting.
I got one idea, if you would want to implement v2 maybe. In USSR concrete blocks used waste products like metallurgical slag as a filler. They were literally called "slagblocks" and contained up to 50-60% of slag by weight.

In the game, there's no slag, but there's ash, a final product of waste burning. Ash has no other purpose as being exported at customs.
You might give it another purpose by using it as an ingredient for concrete blocks.

I like the placement of the cargo stations, nice work.