Abstract: A gas fired melting apparatus for particulate material. The melting apparatus has four successively connected vertically disposed sidewall members, a floor member and a roof member. These members define a cubic melting chamber for containing a freestanding generally conical pile of particulate material to be melted. The sizes, shapes and positions of the chamber radiating surfaces as well as their relative distances from the pile surfaces promote heat transfer to the pile. A high temperature gas fired burner is mounted in each sidewall adjacent to the corner formed by the tail end of one sidewall and the head end of a successive sidewall member. The axis of each burner is parallel with its successive wall member so the combined effect of the burners is to produce a toroidal flow of combustion products in the melting chamber around its central vertical axis.