537 posts
Re: Clinker Stored in an Open Yard
norew:
Prior to storage fCao is only 1.98 several days after it was placed in our open yard fCaO rose to 3.57 that was after drying.
That is exactly what you would expect after a few days. The additional 1.59% Free Lime is actually Ca(OH)2, which is released from the reaction of clinker minerals with water.
If you analysed the clinker by XRD, you would find that the actual Free CaO had slightly dropped, due to hydration of Free CaO close to microscopic open pores. After several weeks of exposure to water, the XRD free lime would have dropped dramatically. Eventually, so would the result obtained by the glycol/ethanol titration method. This is due to the reaction of Ca(OH)2 with atmospheric CO2 to form CaCO3.
Regards,
Ted.
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99 posts
537 posts
Re: Clinker Stored in an Open Yard
Hello Norew,
As well as the increase in Ca(OH)2, the quality of the clinker is reduced by the loss of clinker minerals due to hydration. The reaction with water therefore reduces the overall amounts of C3S, C2S and C3A present in the clinker. If this loss is not compensated for, there is likely to be a serious reduction in cement performance.
Also clinker grindability may be negatively affected due to the strengthening of the clinker nodule matrix. ie open pores and cracks reinforced with hydration products and nodules being cemented together into hard lumps.
Regards,
Ted.
99 posts