In 1984, Padaeng Industry constructed a zinc refinery in Tak province, 96 kilometres from the Mae Sot Mine, for the production of zinc ingots. The initial production capacity of 60,000 metric tons per year was increased to 72,000 metric tons per year in 1987. In 1988, zinc die-casting alloy No. 3 was added as an additional product, and in 1997, the overall production capacity reached 110,000 metric tons per year.
With the reduction of raw material resources available at Mae Sot Mine, Padaeng Industry changed its smelting process in 1995, and began incorporating calcine as a feedstock. With the new smelting process, Padaeng Industry became one of the few smelters in the world capable of using both zinc silicate and zinc sulphide in the same production process.
2009 : Re-cretificated the ISO 9001:2008 accreditation for quality management, the ISO 14001:2004 accreditation for environmental management and the OHSAS 18001:2007/TIS 18001:1999 occupational health and safety accreditation. 2007 : ISO/IEC 17025 : 2005 recertification for its testing laboratory in the scope of accreditation for testing zinc ingot, zinc alloy, zinc oxide and zinc silicate from the Thai Industrial Standards Institute (TISI). 2006 : ISO 9001 recertification for quality management system ISO 14001 certification for environmental standards TIS / OHSAS 18001 recertification for management of occupation health and safety standards from SGS (Thailand)
2008 : Received the outstanding labour relations and welfare from the Department of Labour Protection and Welfare, Ministry of Labour. 2008 : Received the outstanding metallurgy industry award from the Department of Primary Industries and Mines under the Ministry of Industry. 2008 : Received the outstanding award for safety, occupational health and working environment from the Ministry of Labour. 2005 : Received award for good performing metallurgical plant from Department of Primary Industry and Mines (DPIM), Ministry of Industry. 2005 : Received award for the outstanding enterprises in labour relations and labour welfare from Department of Labour Protection and Welfare, Ministry of Labour. 2005 : Received the outstanding energy conservation award from the Ministry of Energy .
94 Moo 1, Ban Klonghuaysai Asian Highway 409-410, Nongbuatai subdistrict, Muang district, Tak 63000, Thailand