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Acid Plant Database  September 10, 2021


Padaeng Industry Public Co., Ltd.

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15 Padaeng
Tambol Maptaphut
Amphur Muang
Rayong 21150


Background The company was established on April 10, 1981 with original registered capital of Bt20 million invested by the Thai public (Ministry of Finance), private investors and Belgian private company Vieille Montagne SA. Padaeng Industry has since engaged in mining and refinery operations with the objective of producing zinc metal and zinc alloys to satisfy customer demand. The company’s mine is located in Mae Sot district, Tak province, which borders Myanmar. The smelter is located in the city of the same province. The roaster plant is located in Rayong and the company’s head office is in Bangkok. The company has also engaged in zinc ore exploration programmes in Thailand and in neighbouring countries.
Website www.padaeng.com
Plant -
Coordinates 12° 41' 13" N, 101° 7' 31" E
Type of Plant Metallurgical
Gas Source Zinc Roaster
Plant Capacity 420 MTPD
Status Shutdown
Year Built 1994
Technology Lurgi
Contractor -
Remarks -

Since 1995, Padaeng Industry has imported zinc sulphide as a feedstock for the refinery. Because of its slightly different properties, zinc sulphide must first be roasted to form the oxide “calcine” before the zinc can be extracted.

The company has converted its operations to include a facility to produce zinc oxide (calcine). This facility is located on the grounds of the Padaeng Industrial Estate at Map Ta Phut in Rayong province on the eastern seaboard of Thailand, which began operations mid-1995. Zinc sulphide is converted into calcine during the roasting process, while the sulphur constituent is converted into saleable sulphur acid. The calcine is then delivered to the zinc smelting plant in Tak province.

References -
News April 4, 2008 - Nyrstar NV (“Nyrstar”), the world’s largest producer of zinc metal and alloys, today announced that it has reached agreement to divest its 24.9% minority shareholding in Padaeng Industry Public Company Limited (Padaeng) to a consortium of investors, represented by Asia Plus Securities Public Company Limited, for €34 million in cash.  The shareholding had a book value of €50 million at 31 December 2007, which was based on Padaeng’s share price at the time Nyrstar was established. Accordingly, and based on the current exchange rate, the transaction will result in a loss of €16 million, reflecting the decline in Padaeng’s share price since 31 August 2007 as well as the decrease in the value of the Thai baht against the Euro.  Umicore SA/NV, one of Nyrstar’s founding shareholders, also announced that it has divested its 22% shareholding.
Padaeng, listed on the Stock Exchange of Thailand, operates a silicate zinc mine and a smelter in Tak province, as well as a roaster plant located in Rayong province. Production of zinc metal and alloys is focused on the domestic Thai market.
Nyrstar felt that its minority investment in Padaeng, without the potential for operational control, meant that it was a non-core asset. Any increase to Nyrstar’s holding reaching 25% of the total voting shares in Padaeng would have resulted in Nyrstar being required to launch a mandatory tender offer for all outstanding shares. However, due to Thai regulations restricting foreign ownership of natural resource assets to less than 50%, Nyrstar would have been precluded from acquiring control of the business.  “Our minority interest in Padaeng meant we had limited influence over the company and due to Thai regulations would not have been able to secure control. Our decision to sell releases additional capital that can be better deployed elsewhere.” said Paul Fowler, chief executive officer of Nyrstar.

MTPD - Metric Tonne per Day           STPD - Short Ton per Day
MTPA - Metric Tonne per Annum      STPA - Short Ton per Annum
SA - Single Absorption
DA - Double Absorption

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