Complex sentence: Processing of raw zisha yixing clay involves removing the clay from the underlaying strata, drying it under the sun in open stall, and then pulverizing the dried clay particles, and using air screening to isolate clay particles of the finest grit size.
Split into simpler sentences: Processing of raw zisha yixing clay involves removing the clay from the underlaying strata, drying it under the sun in open stalls, and then pulverizing the dried clay pieces into fine particles. The clay powder then undergoes air screening to isolate clay particles of the finest grit size.