Peru’s Cementos Pacasmayo SAA said Wednesday its Atlanta-based subsidiary, Zemex Corp., has bought the Kings Mountain, N.C., mica operations of Oglebay Norton Specialty Minerals, Inc.  Oglebay Norton Specialty Minerals is a subsidiary of Oglebay Norton Co. Oglebay Norton said the sale was worth $15m.  "The plant has production of about 30,000t of mica a year," Cementos Pacasmayo said in a filing to the Peruvian securities regulatory agency, Conasev.  Zemex Corporation produces industrial minerals, with facilities across the U.S. and Canada.