an apparatus and method operable to : feed a granulated feedstock into a chamber ; apply a melting or sintering energy in programmable scans producing a material deposit overlaid with slag in the chamber ; position a slag removal device such that its cutting surface is coincident with a top surface of the material deposit ; cut or break the slag free from the material deposit with the slag removal device ; separate the removed slag from a reusable portion of the granulated feedstock in a separator ; and feed the reusable portion of the granulated feedstock to the top surface of the material deposit for repeating the above operations .