smelter workers tapping raw matte slag inside a furnace hall — glowing molten material pours into metal containers as laborers guide the flow with long iron tools amid flames, smoke and intense heat - 長柄勺 幅插畫檔、美工圖案、卡通及圖標
antique image: scientific experiment, liquefaction of air by charles e tripler, crushed iron dipper - 長柄勺 幅插畫檔、美工圖案、卡通及圖標