The modernisation programme is being implemented at the Krasnoyarsk (KrAZ) and Bratsk (BrAZ) aluminium smelters, the company's two largest production facilities.
Until 2020, Rusal plans to switch nearly 2.1 million tonnes of its aluminium production capacities to EcoSoederberg technology (out of 2.3 million tonnes currently running on Soederberg).
The first experimental EcoSoederberg cells were launched at KrAZ back in 2009. Since 2010, 286 of the facility's cells have been switched to the new technology, including 89 cells in potrooms 3-6 in 2013. The amount of aluminium produced at the plant's EcoSoederberg cells was 160 kt in 2013, or 16% of the total output. In 2013, KrAZ emissions were cut by 3% y-o-y, according to preliminary estimates. 2014 will see cell retrofitting start at KrAZ potrooms #1, 2, 9, 11-23, while BrAZ will continue EcoSoderberg introduction at its experimental potroom (#8).
Commercial operation of the technology at KrAZ has confirmed the environmental and economic effectiveness of introducing the EcoSoederberg technology. The use of EcoSoderberg technology allows carrying out cell retrofitting with no more than 300 USD/t Al of capital cost. It also reduces the volume of liquid aluminium used in cell (the technology reduces the amount of metal in cell by 30%) that leads to a decrease in working capital. Moreover, it improves a number of technical indicators, in particular, higher energy efficiency decreases production costs by nearly USD 4.5/t.
The introduction of EcoSoederberg which is a unique development of the Engineering and Technological Centre of RUSAL (ETC) involves a number of innovations: Improvement of the design of the Soederberg cells, lining, gas evacuation system and the use of entirely new raw material – colloidal anode paste.
Colloidal anode contains a much lower amount of pitch, which is the main source of tar substance emissions. Improved gas evacuation system enhances cells’ structure that results in substantial emissions reduction.
“In terms of eco-efficiency, EcoSoederberg is very close to the cleanest technologies used in the industry, in partiular, to the baked anode technology. It is EcoSoederberg that will open a new page in life of the world’s two largest aluminium smelters,” said Viktor Mann, Technical Director of UC RUSAL.
The target to develop EcoSoederberg technology was set in 2002. In 2005, EcoSoederberg R&D programme was officially launched. Investments in the R&D project from 2005 to 2014 totalled USD28.9 million (VAT included). Investments in EcoSoderberg introduction programme from 2010 to 2020 are expected to reach USD122 million.