1. Iron ore mining and processing:
There are two kinds of hematite and magnetite that have better smelting performance and utilization value.
2. Coal mining and coking:
At present, more than 95% of the world’s steel production still uses the coke iron-making method invented by the British Darby 300 years ago. Therefore, coke is required for iron-making, which is mainly used as fuel. At the same time, coke is also a reducing agent. Displace iron from iron oxide.
Coke is not a mineral, but must be “refined” by mixing specific types of coal. The general ratio is 25-30% of fat coal and 30-35% of coking coal, and then put into a coke oven and carbonized for 12-24 hours. , forming hard and porous coke.
3. Blast furnace ironmaking:
Blast furnace ironmaking is to melt iron ore and fuel (coke has a dual role, one as a fuel, the other as a reducing agent), limestone, etc., in a blast furnace, so that it undergoes a reduction reaction at high temperature and is reduced from iron oxide. The output is basically “pig iron” mainly composed of iron and containing some carbon, that is, molten iron.
4. Making iron into steel:
The fundamental difference between the properties of iron and steel is the carbon content, and the carbon content is less than 2% is the real “steel”. What is commonly referred to as “steelmaking” is the decarburization of pig iron during the high-temperature smelting process, turning iron into steel. Commonly used steelmaking equipment is a converter or an electric furnace.
5. Casting billet:
At present, in addition to the production of special steel and large-scale steel castings, a small amount of cast steel ingots are required for forging processing. The large-scale production of ordinary steel at home and abroad has basically abandoned the old process of casting steel ingots – billeting – rolling, and most of them use The method of casting molten steel into billets and then rolling them is called “continuous casting”.
If you do not wait for the steel billet to cool down, do not land on the way, and directly send it to the rolling mill, you can make the required steel products “in one fire”. If the billet is cooled halfway and stored on the ground, the billet can become a commodity sold in the market.
6. Billet rolled into products:
Under the rolling of the rolling mill, the billet changes from coarse to fine, getting closer and closer to the final diameter of the product, and is sent to the bar cooling bed for cooling. Most of the bars are used for processing mechanical structural parts and so on.
If patterned rolls are used on the last bar finishing mill, it is possible to produce rebar, a structural material called “rebar”.
The above introduction about the production process of rebar, I hope it will be helpful to everyone.
Post time: Jul-22-2022