Abstract: A smelting apparatus for smelting metallic ore comprising a furnace having a continuous curved wall and end walls defining a longitudinal volume having a longitudinal axis in a horizontal direction. The continuous curved wall has a lowermost area. The longitudinal volume is divided in at least three longitudinal layers comprising a top layer within which gasified fuel is combusted for creating a hot gas composition to release, from the metallic ore, at least molten metal and slag, a lowermost layer at the lowermost area for holding molten metal, and a mid-layer above the lowermost layer in which the slag accumulates. The present document also describes processes using the smelting apparatus for producing ferrous and non-ferrous minerals from a metallic ore.