Not only are cement clinker and gypsum used in the production of cemen
t, but in many cases limestone is also added as an interground additiv
e. The CO2 content, which originates almost entirely from the CaCO3 co
ntent of the limestone, is used as the control variable for the metere
d addition of limestone during cement grinding. At present special car
bon analyzers are generally used for determining the CO2 content of th
e cement. However, incorporating this equipment in an automated labora
tory is technically complicated and therefore also very cost-intensive
. A technically problem-free and more economical method for the determ
ination of CO2 is X-ray diffraction. X-ray diffraction analyzers are n
ow established items of equipment in every automated laboratory. The C
O2 content in cement is determined indirectly by measuring the X-ray d
iffraction intensity of a chosen CaCO3 peak. The diffraction intensiti
es are directly proportional to the CO2 contents. The results of inves
tigations carried out show that a measurement accuracy of significantl
y better than +/- 0.1 % can be achieved by X-ray diffraction.