Powder and ash smelters.
Heavy metals in ashes can be stabilized and powders sintered or unharmed. (Asbestos.)
These smelters are also used for the production of Nanopowders. The slurry is injected into the tail pipe of a pulse combustor. Due to the force of the explosions in a pulsating combustor the result is a very active and open powder, with a high surface to weight ratio.