Dear All,
Our plant is using High grade limestone as filler for cement grinding. We are going to change the limestone source, but this material is contaminated a bit clay and dolomite. Anyone can share me the limit of clay can be contaminated in limestone without effect on cement quality? and how can we measure the % of clay in limestone.
Many thanks for your sharing.
Tam Nguyen
Hello Tam.
I have seen values of >2% clay in concrete quoted as causing problems.
I believe there is a titration method for estimating clay contents using methylene-blue dye, but unfortunately I don't have any references. Google?
Best Regards,
Ted.
Thanks, Ted.
Tam
The European norm EN 197-1 2000 states that the amount of clay in limestone used for the production of blended cement must not be over 1,2%.
The quantity of clay is determined by methylene blue test. Procedure is described in norm EN 933-9.
The norms can be purchased from the normalisation institute of any member state, for example at http://www.bsi-global.com/ (British Standards Institute)
Best regards