Potential industrial clays of Alberta : a preliminary assessment, Part II

The oldest rocks tested in this study that have ceramic potential are the basal clays of the Lower Cretaceous McMurray Formation. Some of these clays can be used for low heat duty refractories but most of the material is more suitable for structural clay products or pottery. In the Peace River region pressed bricks made from shales of the Shaftesbury Formation probably could be fired successfully. From the same area, samples of Kaskapau Formation dry well, firing range is moderate to long, and the milk chocolate brown colour could be acceptable in "earth colour" pottery or structural clay products. A sample from the Bearpaw Formation in the Foothills has a long firing range and reasonable drying characteristics, which suggests that further testing of Foothills material may be desirable. Use of clays from the Eastend and Whitemud Formations for ceramic purposes is expected to continue. Shales from the Porcupine Hills Formation seem best suited for their present use as raw material for expanded aggregate production. Structural clay products could be produced from sediments of the Brazeau Formation if the good drying characteristics, moderate to long firing range, low fired absorption, and acceptable fired colours are maintained by active quality control methods. Clays and shales of the Paskapoo Formation have potential for use in the production of structural clay products if blended with grog, quartz or other clays to reduce the tendency to curl on firing.