Mining leases to the Padaeng zinc deposit were granted by the Thai government in 1972 to the Thai Zinc Company. Zinc ore had been mined for several years before the government granted Padaeng Industry in 1982 a 25-year concession to mine zinc ore on a 250-rai (40-hectare) area in Mae Sot district, Tak province. A large deposit of zinc silicate was found. Consequently, a zinc mine named “Padaeng Mine” based on an open ladder structure was opened in 1984.

The Mae Sod mine completed its last zinc ore production in June 2016 after 32 years of operation. In 2016, it produced 279,081 tons of zinc silicate which was 7 % higher than the set target, with a zinc content of 34,500 tons.

After the closure of the mine, PDI restored the environment and turned it back into its original fertile natural forest, in line with the Company’s environmental restoration plan. PDI will hand over the land to the Royal Forestry Department in 2017, in order to develop it into the Royal initiated project called Educational Promotion Project for Environmental Conservation and Restoration.

In addition, PDI has set up Doi Padaeng Zinc Mine Museum as a learning center for the zinc mining and smelting industry. The Company will also construct the Padaeng Mine Relic Pagoda as a spiritual center for the public.