Established on April 10, 1981 and listed on the Stock Exchange of Thailand on July 21, 1987, PDI operates a zinc mine in Mae Sod district and a zinc refinery in Muang district of Tak province and roaster in Rayong. PDI is the sole producer of high grade zinc in Southeast Asia with production of SHG zinc metal and alloys. The company’s vision is to be the leading provider of high quality zinc materials in South East Asia.