What are the types of desulfurizers

Desulfurization agents usually refer to agents that can remove free sulfur or sulfur compounds from fuels, raw materials, or other materials; In the control and treatment of pollutants, it mainly refers to the agents used to remove sulfur oxides from waste gas. Technicians from Luoyang Hehe Industry and Trade introduced that various alkaline compounds can be used as desulfurization agents, and each has its own characteristics. The main desulfurizers used in the pretreatment process of molten iron desulfurization include NaCO3, CaC2, CaO, Mg, and composite desulfurizers based on them.


1. CaO based calcium based desulfurization agent:


The early use of CaO based desulfurizers by many enterprises was mainly a mixed desulfurizer with lime w (CaO)=about 90% and fluorite w (CaF2)=5%~10%. The addition of fluorite and Al to activated lime can significantly improve the desulfurization effect. Lime is a very easy to obtain raw material, with abundant raw materials and low prices. However, the use of lime based desulfurizers is large, with a large amount of slag and a long processing cycle. It also reflects high desulfurization efficiency when the temperature of molten iron is high.


2. Mg and Mg based desulfurization agents:


The equilibrium constant of the reaction between [Mg] and [S] at 1350 ℃ is not as high as that of the desulfurization reaction with calcium carbide and lime. However, metal magnesium and sulfur have a high affinity, and the reaction zone kinetics conditions are very good. The reaction is rapid and very strong. The MgS produced by the reaction of magnesium and sulfur in molten iron has a high melting point (2000 ℃), low density (2.82g/cm3), and is prone to slag formation. However, the activity of magnesium metal is very high, and as a desulfurization agent, passivation treatment must be carried out.


Magnesium can not only be used for desulfurization alone, but also as a magnesium based composite desulfurization agent. The magnesium powder used for magnesium based desulfurizer also needs to be passivated. This kind of magnesium powder is made by milling cutter cutting or spray method, with a diameter of 0.15~1.2mm, w (Mg)=90%, and the rest is passivated coating. Mix the flowability treated calcium oxide powder with magnesium powder to ensure smooth transportation of the concentrated phase. The desulfurization reaction mechanism of magnesium and lime composite desulfurizer is as follows: due to the addition of lime, calcium oxide powder is wrapped and dispersed to evenly distribute magnesium powder in molten iron, expanding its reaction area and slowing down the gasification rate of magnesium, improving the utilization rate of magnesium; CaO can serve as the core of the complex to transport small MgS (1-5 μ m) Aggregation can accelerate the floating of inclusions, continuously reduce the concentration of sulfur in the reflection area, and improve the desulfurization speed, which is conducive to achieving the requirements of rapid and deep desulfurization.


3. NaCO3 based sodium based desulfurization agent:


The method of using soda to sprinkle into the blast furnace tapping ditch for desulfurization is adopted. The liquid sodium oxide decomposed by soda has strong corrosiveness, and the oxide volatilizes to pollute the environment. The good fluidity of the slag generated by desulfurization with soda makes it difficult to remove the slag. Soda prices are also relatively high. So, soda as a desulfurizer is very rare.


4. CaC2 based calcium based desulfurization agent:


Calcium carbide (CaC2) has strong desulfurization ability, and research has shown that the equilibrium constant of calcium carbide powder desulfurization reaction is the highest at a temperature of 1350 ℃ for molten iron. Composite desulfurizers such as calcium carbide, dry coal powder, magnesium or calcium oxide are widely used in industry, such as CaC2 based desulfurizers used by Pangang. However, calcium carbide is highly susceptible to reacting with moisture in the air to generate acetylene gas, which is flammable and explosive. Therefore, the processing, transportation, and