VIJAYAWADA: The AP Mineral Development Corporation (APMDC) has submitted the tender document for selection of an excavation contractor for the Mangampet Barytes mine in Kadapa district to the AP Judicial Preview Commission.APMDC is India’s largest producer and supplier of barytes since 1975 from its mines in Mangampet of Kadapa. The deposit at Mangampet is the single largest deposit in the world and accounts for 95 percent of the Indian reserves.