26 posts
burnability index test method
Dear Ted
I intend to establish a raw mix burnability diagram for my plant, so I would grateful if you let me have any literature on this following :
- Standard burnability index test
- BI (burnability index) reference table base on extensive tests with numerous raw meal samples in order to find BI corresponding to each sample. etc
- the right way to calculate specific heat consumption,should we use the G.C.V (gross calorific value) or N.C.V (net calorific value)? I have seen some calculation that use N.C.V
If you don’t mind, I would be interested to receive further details of these documents as soon as possible. Thank a lot and wish you have a nice day!
Regards
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537 posts
re burnability index test method
Hello Phanminh,
Sorry to take so long to answer your question but I have been on annual leave for a month or so.
Unfortunately the literature I have concerning burnability testing is proprietry information and, as such, I can't release the exact test details publicly. However, I can tell you that the method involves burning nodulised raw meal + coal ash in a laboratory furnace at clinkering temperature for a period equal to the residence time in the burning zone and then testing the resultant clinker for free lime. (you will need a furnace that is capable of 1500degC)
The higher the free lime of the clinker produced, the harder the raw meal is to burn. A scale similar to the following is normally used;-
Free CaO Burnability
0 - 1% Excellent
1 - 2% Very Good
2 -3% Good
3 - 4% Good - Moderate
4 - 5% Moderate
5 - 6% Moderate - Poor
6 - 7% Poor
7 - 8% Very Poor
>8 Extremely poor
NOTE: This method is comparative. Therefore you have to perform quite a lot of base-line tests on your normal kiln feed before making any improvements to the burnability of the kiln feed. But once you have this 'normal' base-line data, this test will tell you if any changes to the process have significantly improved the kiln feed burnability or not.
More can be found regarding raw meal burnability in this paper by Linda M. Hills et al;-
http://www.asocem.org.pe/bivi/sa/dit/icem/G2-2002.pdf
To calculate the specific heat consumption you need to use the net calorific value (N.C.V) of the fuel(s). The N.C.V. allows for the energy lost due to the formation and vaporisation of water (both water contained in the fuel and water formed from the hydrogen and oxygen in the molecular structure of the fuel itself.)
Hope this helps...
Regards,
Ted.
26 posts
re burnability index test method
Dear Ted
Thank for your suggestions. Its very helpful for my plant.
About the specific heat consumption, it could be more exactly if we use Net C.V of the finecoal (include the kiln dust) to make a calculation, right?
best regards
phanminh
537 posts
re burnability index test method
Hello Phanminh,
Yes, since fine coal rate is normally measured fairly accurately it is the best measure of coal usage for the specific heat consumption calculation. However, you must use the N.C.V. of the fine coal reported on an 'as received' basis. The N.C.V. calculation must also take into account the total moisture remaining in the fine coal.
Regards,
Ted.