This U.S. industry comprises (1) establishments primarily engaged in developing the mine site and/or mining kaolin or ball clay (e.g., china clay, paper clay, and slip clay) and (2) establishments primarily engaged in beneficiating (i.e., preparing) kaolin or ball clay. Cross-References. Establishments primarily engaged in calcining, dead burning, or otherwise processing (i.e., beyond basic preparation) kaolin and ball clay are classified in U.S. Industry 327992, Ground or Treated Mineral and Earth Manufacturing.