Understand the technological process and principle of blast furnace smelting.

Blast furnace production is continuous. The first generation blast furnace (from blowing-in to overhaul and shutdown) can be continuously produced for several years to more than ten years. During production, iron ore, coke and flux are continuously loaded from the furnace top (generally, the furnace top is composed of materials and hoppers, while the modern blast furnace is bell-shaped valve top and bell-less top), hot air (1000 ~ 1300℃) is blown from the tuyere at the lower part of the blast furnace, and fuels such as oil, coal or natural gas are injected. The iron ore charged into the blast furnace is mainly a compound of iron and oxygen. At high temperature, the carbon in coke and injection and carbon monoxide produced by carbon combustion take away the oxygen in iron ore and get iron. This process is called reduction. Iron ore is refined into pig iron through reduction reaction, and molten iron is discharged from the taphole. Gangue in iron ore, ash in coke and injection are combined with flux such as limestone added into the furnace to generate slag, which is discharged from the taphole and slag outlet respectively. The gas is led out from the top of the furnace and used as industrial gas after dust removal. Modern blast furnaces can also use the high pressure at the top of the furnace and some derived gases to generate electricity.

Principle:

The principle of ironmaking (how iron ore is ironed) uses reducing agent to reduce iron oxide in iron ore to metallic iron.