Russian Federation aluminium giant UC Rusal said yesterday that the Krasnoyarsk Aluminium Smelter (KrAZ) has completed the transition to emissions-reducing EcoSoderberg technology.
Per Rusal, the technology utilizes a design that traps exhaust fumes from the production process, which, along with the optimized anode paste composition, seals off a high degree of tarry materials along the way. As a result of the just-ended second stage of modernization at the plant, total emissions have dropped by 13.7 percent, with a 30-percent drop in hydrofluoride emissions along the way.
The US$74-million project saw the modification of over 1,900 reduction cells to EcoSoderberg technology. Altogether, Rusal has invested in excess of US$390 million at the plant on modernization efforts.
“The introduction of the EcoSoderberg process is a key part of the Company’s modernization program,” explained Rusal’s CEO Evgenii Nikitin. “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.”
Rusal’s upgrades began sixteen years ago and are carried out in a two-stage process, with the first consisting of installing a gas treatment system and various new automations to the plant. The second stage is the one just completed at KrAZ. Altogether the new technology has cut total emissions by 38 percent, including a 76-percent drop in fluoride emissions. Per Rusal, the smelter’s total emissions are 4.5 times below levels measured in 1980.