In alignment with its broader Environmental Policy, UC RUSAL is implementing measures to reduce its adverse impact on the atmosphere.
The Company has set a goal for UC RUSAL enterprises to meet by 2020 atmospheric emission standards established by the laws of countries where the enterprises operate.
Total emissions of pollutants into the atmosphere in 2015 fell by 2.1% compared to the previous period, and generated 314 thousand tonnes. In addition to the presence in the reporting year, as in 2014, of mothballed capacities, the reduction in this indicator was also due to the performance of transitional measures of air protection.
The structure of overall emissions by line of production remains largely unchanged – aluminium smelters account for the largest proportion of pollutants emissions. In the reporting period their share has increased by 1 percentage point up to 73%. Alumina refineries accounted for 8% (vs. 9% in 2014), heat and electricity – also 8% (vs.10% in 2014). Other production facilities contributed to 11% of total emissions of pollutants.
Among the air pollutants discharged by UC RUSAL enterprises, the largest portion consists of carbon monoxide which has the least adverse environmental impact. In the reporting period, this indicator equalled 199.6 thousand tonnes (vs. 202.8 thousand tonnes in 2014), or 64% of the Company’s total emissions. Emissions of this pollutant were reduced by 1.6 pct compared to the previous period.
While a positive trend towards a reduction in overall emissions of pollutants can be observed, the structure of emissions of pollutants by type remains the same: the largest share are solid particles (except for benzo(a)pyrene, solid fluorine, tarry matter) - 44.2 thousand tonnes or 39% of total emissions; then sulphur dioxide - 34.8 thousand tonnes or 30%; nitrogen oxides - 17 thousand tonnes or 15%; gross fluorine (solid and gaseous) - 7.7 thousand tonnes or 7%; and other substances (9%).
In the reporting period the Company continued its work to upgrade its main production facilities and gas purification units (GPU), including the transition to the new EcoSoderberg technology.
- The pilot project of electrolysis cells (pots) modernization was completed in four buildings at KrAZ. Since 2015 the EcoSoderberg technology has spread across the whole smelter — 339 pots were converted to the new technology. It is expected that the entire plant will be converted to this environmentally advanced technology by the year 2018.
- KrAZ has launched a trial operation of the plant for sulfur recovery from gas treatment system solutions. This action allowed the running of the second step of gas purification, making it the most efficient among alternatives, reducing the degree of danger of waste being stored, and obtaining a marketable product - sodium sulfate.
- Anode production is in the process of modernization which will reduce the emissions of tarry substances.
- The environmental protection measures undertaken by KrAZ in 2015 reduced the total amount of pollutant emissions to the atmosphere in Krasnoyarsk by 1.3%
- The plant completed modernization of 90 pilot electrolysis cells with the installation of the automatic raw material feed system. The eco-friendly electrolysis cells specially designed for BrAZ are characterized by increased daily metal output with simultaneous energy savings, almost eliminating losses of fluorine-containing raw materials which are sealed to the maximum. Due to the automation of the major part of the processes with new electrolysis cells, staff labour costs were reduced.
- BrAZ continues to introduce modern gas treatment facilities. Their efficiency in terms of trapping major pollutants exceeds 99%. In the reporting year the plant has commissioned a dry gas purification unit (GPU), and construction and installation of two more units are at the stage of completion,. In total, 13 units are expected to be installed upon completion.
- Novokuznetsk Aluminium Smelter continues the conversion of Soderberg electrolysis cells to the prebaked anode technology. Five PA-167 electrolysis cells were installed in the reporting period. NkAZ plans to replace 15 electrolysis cells during 2016 and to replace the electrolysis cells part and gas purification capacities within the period 2019-2020.
- Within the frameworks of the EcoSoderberg project realization, Irkutsk Aluminium Smelter plans to convert the 1st, 3rd and 4th series of IrkAZ electrolysis to this technology*. This will reduce emissions released into the atmosphere by 30% and improve the environmental indicators of the production process. Other technological and technical events include increasing the efficiency of foam and wet gas purification units and the replacement of electric separators.
- Achinsk Alumina Refinery has launched a large-scale Program for reconstruction of its dust and gas purification equipment. In the course of reconstruction, sintering furnaces will have 36 wet-type units to be used as the second additional cleaning step, after electrostatic filters on all furnaces. The equipment will allow the smelter to reach the purification from flue gases and dust up to 98%. In 2016 the Company plans to implement such units at eight furnaces. A closed system of water use will be applied to the new cleaning equipment.
- Within the project for gas purification units reconstruction, a new electric separator has been installed in NGZ after the lime kiln No. 3. This measure will reduce the amount of kiln emissions up to the level 50 mg/nm³, which meets the national standards.
- The plant has started the operation of the unit AirPure, which collects, filters and condenses vapours of the coolant used in cold foil mill. The unit operation allows the reusing (coolant) vapour return which is no longer released into the atmosphere, thus contributing to significant environmental benefits and notably improving working conditions. Moreover, foil production costs are reduced due to the regeneration and return of trapped vapours (GM) which reduce the cost of manufacturing the foil.
Enterprises such as Kremniy and SUAL Urals Silicon continued reconstruction of the gas treatment facilities.
UC RUSAL enterprises pay considerable attention to implementation of the activities in the context of environment monitoring.
In the reporting year the sanitary and industrial laboratory of KrAZ obtained new equipment for analyzing carbon monoxide concentrations with greater precision and with a wider range of concentrations measured. Laboratory experts monitor on a regular basis concentrations of the substance in industrial emissions, working areas, as well as on the borderline of the sanitary protection zone and in five points of the residential area.
KrAZ plans to introduce automatic measuring instruments for pollutants emissions in conformity with the new requirements of the Russian laws which will take effect in 2018. The information will be sent to the state ecological monitoring fund. Some substances, such as dust, are already monitored with devices installed at KrAZ as part of the transition of factories to the EcoSoderberg technology.