Krasnoyarsk smelter runs with Eco Soderberg technology

Rusal has completed the conversion of its aluminium smelter in Krasnoyarsk to Eco Soderberg technology.

Rusal a leading global aluminium producer, has announced that its Krasnoyarsk Aluminium Smelter (KrAZ) has completed its transition to the Eco Soderberg technology. The recently completed retrofitting project on the smelter involved modifying a total of 1954 reduction cells to use the Eco Soderberg process. During this environmental retrofitting stage alone, USD 74 mln was invested in the project. In total, between 2004 and 2019, KrAZ allocated over USD 390 mln towards the implementation of various modernization projects.

The Eco Soderberg process was developed by the Engineering and Technology Centre of Rusal. It was also included in the Reference of the Best Available Technologies in the Aluminium Production section approved by Rosstandard. Experts have concluded that the Eco Soderberg process is one of the most efficient and environmentally-friendly production processes in the aluminium industry to date.

The Eco Soderberg process uses an improved design of the exhaust fume removal system which ensures a high degree of hermetic sealing as well as an optimized anode pastе composition. This results in a significant reduction of emissions, particularly for the emissions of tarry materials. During 2011-2020, the second stage of KrAZ eco-modernization allowed the smelter to reduce total emissions by 13.7 %, while hydrofluoride emissions reduced by 30 %.

“The introduction of the Eco Soderberg process is a key part of the Company's modernization program. At the moment, in addition to KrAZ, the process is being introduced at Rusal's other smelters, such as BrAZ, IrkAZ, NkAZ and VgAZ. In total, we plan for 400 reduction cells across five smelters to changeover to the new process this year. A new system of gas treatment has improved hermetic sealing of the cells, allowing us to effectively catch more than 99 % of fluorides, 99.5 % of benz (a) pyrene, and at least 96.5 % of sulphur oxide. The next stage of our retrofitting efforts will involve deployment of inert anode reduction cells,” noted Rusal CEO Evgenii Nikitin.

The comprehensive environmental program at KrAZ was launched in 2004 and comprised two stages. The first stage focused on the smelter building and involved commissioning new gas treatment systems, installing an automated production process management system, and introducing the dry anode process. The second stage involved introducing the best available technologies including the modification of KrAZ reduction cells to utilise the Eco Soderberg process.

As a result of the 16-year environmental program, the smelter's total emissions have been cut by 38%, while fluoride emissions are down by 76 %. Today, the smelter's emissions, which end up in the air of the city, are 4.5 times less than they were back in 1980.