Orkedalsøren has been used as a loading port for ore from the copper mines at Kvikne and Løkken, from as early as the start of the seventeenth century. Supplies and equipment for the mines were also brought in through here. In the 1860s the Thams family, after whom the harbour Thamshavn was named, founded a large sawmill for the production of prefabricated wooden houses.
In 1904 Christian Thams founded Orkla Grube Aktiebolag, (The Orkla Mining Company), the forerunner to the present day Orkla A.S. This marked the transition to a modern industrialised form of mining at Løkken, as well as the modernisation of the transport of copper pyrites ore to Thamshavn. The Thamshavn Railway, which was built to transport the pyrites ore to the harbour, was opened in 1908 and was the first electric railway to be constructed in Norway.
In 1930 Orkla built a smelting plant to process the copper pyrites ore from Løkken into pure sulphur and copper matte. In 1964, the first smelting furnace for the production of ferrosilicon commenced operation. In 1981 production was increased with the building of a second larger furnace. An advanced energy recovery and cleansing unit has subsequently been added to the plant. In 1986 the works became a part of the Elkem group of companies.
Elkem Thamshavn is famous for its energy recovery system. It was one of the first smelter plants in the world to use this technology. Today, the plant’s ER system recovers about 30% of the electricity consumed. Elkem Thamshavn is in terms of its products, production equipment, technology, safety and environmental record one of the most modern plants of its kind in the world today.
Metallurgical silicon from Thamshavn is used in the production of silicones, production of polysilicon, production of ceramics and as an alloying element to aluminium.
The filtration of dust in the exhaust gases from the smelting furnaces gives microsilica( 971 grade is only produced in Thamshavn.), the other main product from Elkem Thamshavn.