Desulfurizer and its producing technique

Abstract

The invention discloses a novel desulfurizing agent which can be used for desulfurizing molten iron or molten steel and its manufacturing process. It is composed of stabilizer and binder. It is mixed evenly according to its weight percentage, and then mechanically formed and put into use after drying. In the process of iron or steel tapping, this desulfurizer can be directly added to the iron or steel ladle without Other equipment is easy to operate and has a certain deoxidation effect. It does not cool down during the desulfurization process, the desulfurization product is stable, does not produce sulfur back phenomenon, and the desulfurization rate is stable. It can be popularized and applied in the metallurgical and mechanical industries.

Description

technical field [0001] The invention relates to a novel material and manufacturing process for molten iron or molten steel desulfurization. Background technique [0002] In most cases, sulfur is a harmful element in iron or steel. It is easy to form manganese sulfide network inclusions at the grain boundaries, resulting in reduced plasticity and toughness of steel. At the same time, it also affects the processability, mechanical properties, and toughness of steel. Connectivity and corrosion resistance. In order to reduce the sulfur content in steel, the following four methods are usually adopted: ①removal in blast furnace; ②removal in tapping process or in ladle; ③removal in steelmaking furnace; ④removal in ladle, generally the most economic The process plan is to use the desulfurization outside the molten iron furnace and deep desulfurization of the molten steel in the ladle according to the steel type. At present, there are four generations of desulfurizers, namely soda ...

AI Technical Summary

Problems solved by technology

At present, there are four generations of desulfurizers, namely soda or sodium carbonate, lime, calcium carbide base and magnesium base, etc. The use of soda or sodium carbonate for desulfurization has the following disadvantages: soda or sodium carbonate desulfurization is an endothermic process, and the generated slag is harmful to The lining has a strong erosion effect, and the generated slag is a very dilute fluid that is not easy to separate from the molten iron. During the treatment process, a large amount of smoke and dust are generated, and the sodium oxide in it seriously pollutes the environment; the use of lime desulfurization has the following disadvantages: the desulfurization kinetics conditions are poor, and its Solid reactants and solid products hinder the reaction, so it is necessary to use ultra-fine lime to expose a large reaction area for melting, but fine lime powder will absorb a lot of water, the amount of desulfurizer used is large, and the amount of slag produced is also large, resulting in metal loss It is very sensitive to the blast furnace slag being brought into the molten iron tank. The desulfurization reaction is an endothermic reaction and the temperature drop is large. The disadvantage of using calcium carbide as a desulfurizer is that the transportation and storage of calcium carbide powder must be protected by inert gas, and the amount of use is large. Large-scale and anti-riot protection devices are required, the amount of slag is large, and the amount of metal taken away is large. The processed slag contains unreacted calcium carbide, and the slag needs to be treated separately, and calcium carbide is sensitive to blast furnace slag; The disadvantages of desulfurization agent are: the cost of desulfurization agent is high, magnesium is easy to burn, the melting point and boiling point are low, the desulfurization effect is closely related to the depth of molten pool, the utilization rate of magnesium is not high, and the desulfurization product magnesium sulfide is not very stable. Sulfur reversion is easy to occur under the environment, so the slag removal method must be adopted

From the above four situations, they all need to establish special desulfurization equipment, such as injection equipment and slag removal equipment, so the equipment investment is large, the operation is complicated, and the promotion and application are difficult.