Steel Making in an Oxygen Bottom Blown Converter Furnace
Steel making is the process of adding specific elements and mixtures to carbon-rich iron ore to create a steel alloy with a variety of beneficial properties. This process is done in large-scale industrial furnaces, such as oxygen bottom-blown converters, which are designed specifically to prevent heat loss and facilitate precise regulation of temperature. The purpose of this report is to provide an overview of how steel is made in an oxygen bottom-blown converter furnace.
At the beginning of the steel making process, raw materials such as iron ore, known as “charge stock,” and a variety of alloying elements are introduced into the furnace. The converter is then filled with some of these raw materials and heated up to 1,700 degrees Celsius (3,092 degrees Fahrenheit). At this temperature, the charge stock, which consists primarily of iron ore and other alloy-bearing elements, creates a slag. This slag, a mixture of iron oxides lead by their respective alloys, is then “skimmed” off of the surface of the furnace, along with the excess unburned materials, and collected for disposal. The remaining molten material, known as “hot metal,” is now ready to be further processed.
The next step in the steel making process for an Oxygen Bottom-Blown Converter Furnace is the de-sulphurization of the hot metal. This is done by adding a precise amount of powdered limestone, which is used to bind with and remove the sulfur impurities present in the hot metal. The hot metal is then agitated with oxygen, which raises its temperature to 1,890 degrees Celsius (3,424 degrees Fahrenheit) and helps to further break down the remaining impurities.
At this point, the oxidizing agent, oxygen, is allowed to enter the furnace through a series of openings at the bottom surface of the converter. This oxygen combines with impurities present in the hot metal and causes them to oxidize and bind to the walls of the furnace, producing a slag layer. The slag protects the hot metal from contamination by impurities, facilitates the de-sulfurization process, and aids in the homogenization of the hot metal.
In the final step of the steel making process, excess impurities are then further removed from the hot metal by the introduction of additional alloy-bearing materials. These materials, such as manganese, chromium, and nickel, are added to create the desired steel alloy. Once all of the desired impurities have been removed, the molten metal is tapped, or drained, out of the furnace and cooled to room temperature, at which point it is ready for additional processing and/or purification.
The basic steel making process in an oxygen bottom-blown converter furnace is a complex process, but it is essential for the production of commercial-grade steel. The temperature and atmosphere of the furnace must be carefully controlled to ensure that the steel alloy is created with the desired properties, making it a vital element of the steel making process.
