| The usefulness of a refractory clay depends very much on the quantity
of free silica (quartz) in the clay and has to be determined before the
clay is mined. It has been found that the quartz content can be correlated
with loss on ignition (LOI), Pyromctric Cone Equivalent (PCE),
water of plasticity and Bulk Specific Gravity (BSG) and calcining
temperature ofthe clay. All these correlations indicate that a suitable
clay should not contain more than 20-25 ~,;; quartz for refractory
use. |
