Characteristic value obtained from the mold material balance which estimates the wear per
100kg of cast iron for bentonite and carbon under consideration of their content in the mold material.

These wear figures enable the advanced determination of how much bentonite will be burnt (oolitized, see also Burnt bentonite) after the casting of a certain range. If the wear factor is known, the mold material recipe per batch for bentonite and carbon carriers can be calculated.

The average wear factor for bentonite ranges between 0.25 and 0.40%; that of the carbon carrier between 0.7 and 1.5%. Both depend on the casting modulus and the sand-to-iron ratio.

Therefore, for example, for a target active clay content of 8%, a high wear factor of 0.4, a batch size of 1000kg and a current sand-to-iron ratio of 3, the amount of bentonite to be dosed is approx. 11kg.

Further references:
Mold material control
Mold material cycles
Mold material management
Mold material recovery
Oolitization degree