Paper
ABOUT TINFOS
Tinfos Manganese Plant in Kvinesdal, Norway, also known as Øye Smelteverk, was built in 1974.
Silicomanganese is the main product with an annual production capacity of 180,000 tons made up of standard, low carbon and low boron qualities. The furnaces may also produce high carbon Ferro-manganese with a production capacity of 240,000 tons per year.
The silicomanganese is produced in three 45 MVA submerged arc furnaces, using Søderberg type electrodes. The third furnace was set in to production 23 rd. October 2000, and is running at full capacity. This new furnace has increased the production capacity by approximately 50 %.
The off-gases from the furnace go through several steps before emission to air. The gas is washed with water in venturi scrubbers and passed through cyclones, and then the remaining CO containing gas is burned in the steam boiler of the Tinfos Thermal plant. The thermal plant recovers 10-15 % of the total initial electricity input.
Figure 1 Layout of furnace and cleaning facilities
In 1993 Mercury (Hg) was discovered in the off-gas system at Tinfos. Soon it was discovered that one of the Mn-ores was the largest contributor to the Hg content in the off-gases, also other raw materials contain Hg in various amounts. About 100 kg of Hg has been released per year to the air, as the present limits does not allow more than 15 kg of Hg per year (~ 40 m g/Nm3).
Tinfos has since 1993, in corporation and with financial support from SFT (The Norwegian Pollution Control Authority), carried out several investigations to find an effective way of removing Mercury.