Regarding the ash fusion point of coal, I would appreciate some guidance from experienced teachers
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I would like to ask whether national standards specify any requirements regarding the size of the ash cone in the tests for the ash fusion behavior of coal We have two ash fusion point instruments from different manufacturers. Using the same sample and the same method, the results obtained with the two different instruments differ significantly in terms of temperature. Moreover, the two instruments require different sizes for the ash cone. I would like to know whether the size of the ash cone affects the results? The difference between the softening temperature and the flow temperature is only 1-2 degrees; is this also related to the size of the ash cone?
So could you tell me what might be the possible reasons for such large differences in data between two instruments when I use them in the same way? There are also national standards that specify requirements regarding the particle size of ash samples. The standard coal used by me comes from the **Coal Quality Supervision and Inspection Center**, but it seems to have a coarser particle size compared to the ash samples we usually use – is this related to that? Thank you
For certain coal types, the transition from softening to flowing may occur over a range of about ten degrees. This phenomenon is often accompanied by a lower ash content on an air-dried basis for the coal sample, usually around 5%. 2. The coal ash is reddish-brown with a high iron content. 3. Coal ash shrinks significantly when heated. So there may be a difference of a few degrees between the softening temperature and the deformation temperature. It is a normal phenomenon. Some are grayish in color, and indeed have a coarser particle size. If the measured value falls within the range of the standard value and its uncertainty, it’s OK. If the measured value differs from the standard value by 40 degrees, a weakly reducing atmosphere is considered acceptable
Oh, I see. Thank you so much. Are there any books on this topic, or could you recommend any training institutions that offer courses on this subject?
I would like to ask whether you are working in a weakly reducing atmosphere or an oxidizing atmosphere. In an oxidizing atmosphere, there shouldn’t be significant deviations; in a weakly reducing atmosphere, could the presence of air leaking into the instrument be causing such issues? We are using the AF3000 from Changsha Kaiyuan. This kind of situation you mentioned has occurred before; we mainly check whether there is any damage to the furnace chamber and sealing gaskets, and whether they need to be replaced