Each of these eight pallets of kaolin are being sampled to screen them for oversize particles. The 50 gram samples needed can be taken without having to open the bags, they are filled through a valve at the top and it can be opened easily. Kaolins and ball clays especially are suspect and body manufacturers must be vigilant about this (each can tell you disaster stories about making product with faulty raw materials containing grit, carbon and iron particles). The samples will be washed through 70, 100 and 150 mesh screens to spot any particles that could introduce grit or fired speckle into the bodies.
Ceramic materials are employed in the ceramic industry to make glazes, bodies, engobes and refractories. We study them at the mineral, chemical and physical levels.