
Cao | Sio2 | Al2O3 | SO3 | Mgo | L.O.I | F.L | SUM |
64.3 | 21 | 3.8 | 2.7 | 2 | 0.57 | 4.7 | 99 |
LSF | S.M | A.M | C3S | C2S | C3A | C4AF | 2C3A+C4AF |
93.9 | 2.4 | 0.74 | 42.7 | 28 | 1.42 | 15.3 | 18.2 |
Cao | Sio2 | Al2O3 | SO3 | Mgo | L.O.I | F.L | SUM |
64.3 | 21 | 3.8 | 2.7 | 2 | 0.57 | 4.7 | 99 |
LSF | S.M | A.M | C3S | C2S | C3A | C4AF | 2C3A+C4AF |
93.9 | 2.4 | 0.74 | 42.7 | 28 | 1.42 | 15.3 | 18.2 |

Hello Sunlight.
Please have a look at this thread;- http://www.cemnet.com/Forum/thread/150028?page=1 (especially the photo of the interior of the clinker boluders on page 2)
It sounds like you may have a similar problem. Have you broken open the clinker balls and looked inside? Chemical testing of the outer, middle and centre portions of the balls would also be useful.
The high SO3 and Free Lime in these balls indicates that the centre still contains unburned material. This can only happen if large slabs from smoke-box/preheater buildups (or lumps of a sulphur-rich ring near the kiln inlet) break off and pass through the burning zone, creating large clinker balls which are still unburned in the centre.
If this is the case, the cause is invariably reducing conditions (high CO) in the kiln inlet due to insufficent oxygen. This results in strongly increased sulphur recirculation and subsequent sulphur rich buildups or rings which may periodically break loose and pass through the kiln, ending up as large "clinker" balls. Some balls may even grow and form huge boulders as they roll around behind a ring further down the kiln.
Regards,
Ted.

Good day.
Yes you are right, i did notice a small change approx. 10 mins less on the initial setting time. The 28 days strength remains basically the same though.
Thank you very much for your help
One final question though, just to confirm if you did not say already, the small increase in sulfate, will it cause unstable burning conditions in the kiln?
Thanks

Hello Stephen,
No, the change in clinker SO3 that you have described here would not cause unstable burning conditions. Theoretically, there should be a slight improvement in burnability due to a very slight increase in liquid phase, but it is more likely that this small change would not be significant.
Regards,
Ted.