The effect of atmosphere on the ash fusion point
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The inside of the gasification furnace has a reducing atmosphere, whereas the ash fusion point is determined in an oxidizing atmosphere; as a result, the obtained ash fusion point is likely to differ to some extent from the actual ash fusion point inside the gasification furnace. Some sources state that the ash melting point obtained in an oxidizing atmosphere is 50 degrees higher than that in a reducing atmosphere. I wonder if this is actually the case. Please ask an expert to clarify this
That’s what it says in the materials I’ve seen as well! The reason is iron. In a reducing atmosphere, iron exists in the form of ferrous oxide (melting point 1420). In an oxidizing atmosphere, it exists in the form of iron oxide (melting point 1535). The two are different, and iron also forms eutectics with silicates. As for 50 degrees, it is not a fixed value but rather a trend that is related to the content. But it’s probably just in the low tens of degrees. It’s just my personal opinion; I hope it can help you. If there are any mistakes, I hope experts can correct them so we can all learn together*:)
2# Fan Qiang: The amount of iron oxide in the ash varies greatly depending on the type of coal; it can be as low as 1% in some cases and over 30% in others, which has a significant impact on the melting point of the ash
This post was last edited by GSP on 2010-5-4 at 11:25. When carbon or coke is added in a confined space and undergoes incomplete oxidation to produce carbon monoxide, a weakly reducing atmosphere is present during the determination of the ash melting point; who said it’s an oxidizing atmosphere?
Different methods – what if I have more oxygen? Isn’t it just an oxidizing atmosphere?
3# cf19491949 Thank you!
The melting point analysis of coal ash that is carried out nowadays can be done in either a reducing or an oxidizing atmosphere; the client just needs to inform the analysts when planning to conduct the coal sample analysis! According to the information, there are differences under different atmospheres.
What was said on the 7th floor is correct; you can just refer to the national standards. Both oxidizing and reducing atmospheres can be used. Considering the operating conditions of the gasification furnace, a reducing atmosphere is more appropriate as it better reflects the actual working conditions. Additionally, some experts suggest using the average of the oxidizing and reducing atmospheres
There is also information on this issue on the forum; I’m uploading it in the hope that it will be helpful to everyone. http://www.namipan.com/d/%e7%85%a4%e7%81%b0%e7%86%94%e8%9e%8d%e6%80%a7.pdf/0ac9fd39696bffab3659b4db87b8c062001f63c761fb0100