Blast furnace slag;; blast furnace slag (ggbs) is the smelting of pig iron from the blast furnace as a slag discharged. In the blast furnace pig iron, the raw material from the blast furnace to join, in addition to iron ore and fuel (coke), but also by adding flux. When the furnace temperature reached 1400 a 1600 ℃, the flux occurred with the high-temperature reaction of iron ore pig iron and slag. Blast furnace slag from the gangue, ash, flux and other impurities can not enter in the composition of pig iron, is a fusible mixture. From the chemical composition point of view, portland blast furnace slag are of quality materials. 1t per pig iron production, blast furnace slag as the emissions of ore grade and metallurgical methods vary. For example, when the use of depleted iron ore, per ton of pig iron output of 1.0 a 1.2t blast furnace slag; with rich iron ore, each t only the output of pig iron blast furnace slag 0.25t. Mineral and iron because of modern technology, the improvement of blast furnace slag per ton of pig iron output volume has declined dramatically.
As the iron species and composition of raw materials and changes in the operation of process factors, the composition and nature of the slag are also different. In accordance with the varieties of pig iron smelting, blast furnace slag can be divided into cast iron slag, steel slag and special pig iron pig iron slag. Accordance with the chemical composition of blast furnace slag in the amount of alkaline oxides. Blast furnace slag slag can be divided into basic, neutral and acid slag slag.