Ironmaking is obtained by fully mashing iron ore, stirring it and calcining it at high temperature in a blast furnace. Blast furnace ironmaking will produce a lot of slag. The slag produced by blast furnace ironmaking does not contain gold, but contains a small amount of trace metal elements such as manganese, cadmium and nickel, because these metal elements are easy to occur in the veins of iron ore, while gold elements do not occur in the veins of iron ore. Therefore, manganese, chromium, nickel and other trace metal elements can be extracted from the slag of iron smelting furnace, but gold cannot be extracted.