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Introduction
In the metallurgical production process, the steel three deslagging is an important key link before steel smelting process. It can not only effectively reduce the silicon, phosphorus and sulfur content in molten iron, but also reduce impurities and improve the quality of molten iron. In the process of steel three deslagging, it is essential to accurately measure the content of silicon, phosphorus and sulfur in molten iron. Therefore, it is of great significance to measure the content of silicon, phosphorus and sulfur in molten iron before steel three deslagging.
1. Analysis of silicon content
Silicon is the most abundant element in molten iron after iron, and its content in molten iron greatly affects the performance of the steel. Therefore, it is very important to accurately measure the content of silicon in molten iron before steel three deslagging. In practice, silicon is usually determined by ignition loss. The representative type of experiment is the weight method, which generally uses filter sample. After filter sample is collected from molten iron, the sample is filtered, dried, weighed and placed in a drying box for dehydration for several hours. After dehydration and cooling, the original sample mass is measured. The dehydration process is completed when the sample mass does not change. Later, the sample is weighed, placed in a corundum crucible, and ignited in a furnace, and finally weighed and calculated to get the silicon content.
2. Analysis of phosphorus content
Phosphorus can increase the hardness, strength and wear resistance of steel, but too much phosphorus will make steel brittle, reduce welding and cold processing performance, and even produce hydrogen embrittlement of steel. Therefore, it is very necessary to accurately measure the content of phosphorus in molten iron before steel three deslagging. In practice, the molybdenum blue spectrophotometric method is usually used to analyze the phosphorus content in molten iron. In the experiment, the test solution is obtained by adding nitric acid and sodium hydroxide to the sample, and then adding an appropriate amount of molybdenum blue solution, amorphous carbon powder and reducing agent. After the reaction is completed, the absorbance of the solution is measured with a spectrophotometer to calculate the phosphorus content.
3. Analysis of sulfur content
Sulfur has a great influence on the performance of steel, and over-sulfur decreases the mechanical properties and welding performance of steel. Therefore, it is of great significance to accurately measure the content of sulfur in molten iron before steel three deslagging. In practice, the combustion method and the acid titration method are usually used. The combustion method usually uses the mass spectrometer to analyze the sulfur content of molten iron. The acid titration method is to take a certain amount of molten iron sample, add nitric acid and hydrogen peroxide, boil for about 30 minutes, and cool to room temperature. After cooling and standing for about one hour, the sulfur content can be tested by titration with standard potassium permanganate solution.
Conclusion
In summary, it is very important to accurately measure the content of silicon, phosphorus and sulfur in molten iron before steel three deslagging. The commonly used methods for measuring the content of silicon, phosphorus and sulfur in molten iron are as described above. Accurately measuring the content of silicon, phosphorus and sulfur in molten iron before steel three deslagging can not only improve the quality of steel, but also help to control the production cost.
