lime stone screening for gypson board Consultax
lime stone screening for gypson board It can be seen from Table 1 that the mean values of the activity concentrations of 226 Ra 232 Th and 40 K measured in the gypsum and limestone samples are significantly lower than the median values in the earths crust 35 Bq kg 1 for 226 Ra 30 Bq kg 1 for 232 Th and 400 Bq kg 1 for 40 K except the mean value of the activity