Drones, microfurnaces, sorting robots... Quite a bit of "stuff". Theoretically, the perfect recycling machine would break even on the raw materials used when it

Drones, microfurnaces, sorting robots... Quite a bit of "stuff". Theoretically, the perfect recycling machine would break even on the raw materials used when it has processed the trash equivalent of itself. But that would be Diamond Age level technology, and even then ignoring all energy demands and plain old monetary investment. In reality, even conventional mining tends to use a lot of "helper materials" that are consumed in the ore processing but do not end up being part of the product that is sold to the next step of the supply chain. Reducing the scale from industrial to laboratory only worsens the efficiency of that material use. Energy efficiency of micro vs macro is a lost case anyway, but for the sake of utopianism I'm willing to not dwell on that to much. "Miracle energy source" would be one of the less fantastic assumptions required to make these microfactories actually rise.