What are the processes involved in the production of upstream steel products?
- Collection of raw materials
- Primary and secondary steelmaking
- Continuous casting
- Steel forming
The key to understanding Steel in the Philippines and in most parts of the world, whether countries that are highly industrialized or developing ones, having the proper knowledge and understanding of steel is key to ensuring that steel is used according to its intended purposes to maximize its usage.
Before going into details, there are a few basic classifications of steel that you should know, i.e. the upstream products or products that are produced in its rawest form and the downstream products which are further processed from the upstream products. Hence, the difference since down the line the upstream products are still being manufactured further.
With that being said, the two processes are not simple—they are composed of procedures that are used mostly by steel mills that took lots of research and development! Take a look at the processes included in the production of upstream steel products!
Collection of Raw Materials
Before the steelmaking process begins, you should first have the necessary resources for the job. In this case, recycled metals such as steel scraps, iron ore, coal, and limestone are all required to make the raw steel.
Take note that in recent years, recycled materials have gained popularity as an input of steel mills though traditionally steel production facilities still use iron ore and coal as the main fuel for blast furnaces, “greener” production methods are encouraged to reduce carbon footprints.
The first step in the production of upstream steel products is to create sinter—a mixture of iron ore and limestone that is heated together. This makes the iron suitable for the blast furnace. While the iron is processed, coal is heated into extremely high temperatures to create coke—a somewhat pure carbon material that is used as fuel of the blast furnace.
Take note that these processes are only important for one method of steelmaking—BOS.
This phase has two primary methods: BOS (Basic Oxygen Furnace) and EAF (Electric Arc Furnace). The BOS makes use of the aforementioned raw materials. The sinter is placed within a blast furnace along with the coke. The materials melt, leading to molten iron collecting at the bottom. By this time, a little bit of scrap steel then the molten iron is added into the BOF. Oxygen is then blown onto the molten iron to remove impurities and later converting it to steel.
The EAF is a more modern approach. It only uses scrap steel in its operations. The scrap steel is loaded into an electric arc furnace. There are many specifications and considerations that are needed in charging the EAF depending on the grade of the steel that is to be made. Once fully charged, the roof is lowered to strike an arc on the scrap, the heat that the electric arc creates melts the steel. Same as the BOF, oxygen is blown to remove any impurities.
Steel Mills have the option to use either, although depending on the region where the steel mill is located, the quality of steel scrap would vary hence could affect the outcome of the end products.
This phase involves treating the molten steel produced in the previous step in order to adjust the composition of the steel. It’s done by adding or removing certain elements into the molten iron, and/or manipulating the temperature and the environment. some notable secondary steelmaking processes include: stirring, ladle furnace, ladle injection, and degassing. All of which is but achieved and improved thru constant research and development.
Once the desired specification is achieved, the molten steel is then cast into a cooled mold causing it to solidify into steel sheets. Some steel production processes let the molten steel solidify into a variety of different slabs. But in most cases, they are formed into large rectangular chunks that are cut into desired lengths depending on the applications. Steel slabs are created for flat products, blooms for sections such as steel beams, billets for long products, or thin strips.
In essence, upstream products are composed of these steel slabs, blooms, billets and/or strips. These are then shipped into different steel mills for them to be formed into different shapes and eventually ending up with steel products such as steel plates, steel bars, and steel pipes. In the Philippines, these products are in demand, as notably the nation-building process for construction of infrastructures are mostly upstream products.
Upstream steel products are composed of the steel slabs cast or formed that are meant or intended to be further processed. With the importance of steel in the Philippines, you should be able to know that the production process of these upstream steel products should be of high quality because there are many industries that rely on the quality of steel products created!