· In plants where silica flour is to be produced, drying is often necessary. Drying is done in rotary, oil or gas fired dryers. Dry grinding to minus 100 or minus 200 mesh is done in Mills with silica or ceramic lining and using flint pebbles or high density ceramic or porcelain balls. This avoids any iron contamination from the grinding media.
Knouz was a small silica and feldspar powder producer in Sadat city of Egypt, and they bought a ball mill plant from another China supplier. But it was a very bad quality. Because of no good protection for the classifier wheel, the silica powder wear it very quickly in short time, and they have to make protection themselves.