Basic Oxygen Steelmaking: Introduction
The purpose of the Basic Oxygen Steelmaking (BOS) process is to refine the hot metal produced in the blast furnace into raw liquid steel, which may be subsequently refined in the secondary steelmaking shop.
The main functions of the Basic Oxygen Furnace (BOF) are to decarburize and remove phosphorus from the hot metal, and to optimize the steel temperature so that any further treatments prior to casting can be performed with minimal reheating or cooling of the steel.
The exothermic oxidation reactions that occur during BOS generate a lot of heat energy - more than is necessary to attain the target steel temperature. This extra heat is used to melt scrap and/or iron ore additions.
Typical compositions and temperatures of the hot metal charge and tapped steel are as follows:
%C %Mn %Si %P %S %O Temperature / °C
Hot metal 4.7 0.2-0.3 0.2-1.5 0.06-0.12 0.02 0.0 1350-1400
Steel 0.05 0.1 0.0 0.01-0.02 0.01-0.02 0.06 1620-1720
Learning Outcomes for this Section
After completing this section, you should be able to:
* Describe the BOS process
* List and explain the main chemical reactions that take place during the BOS process, especially with regards decarburization, slag formation and control and dephosphorization
* Take charge of a virtual BOS plant and convert, at minimum cost, hot metal from the blast furnace or desulphurization plant into steel ready for secondary steelmaking
* Decide during the simulation: what additions to make and when to make them; when to blow O2 and when to stop; what process parameters to measure and monitor;
how to respond to events that might occur; when to tap
* Describe the BOS furnace and some of the auxiliary equipment
* Explain the various process control parameters, sensors and models
http://www.steeluniversity.org/content/html/eng/default.asp?catid=24&pageid=2081272081Now don't forget to click the "Next" button to continue viewing and digesting the entire module... You may just learn something new here! ;)
respectfully,
Henry
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