Aluminum Plant Research Articles

Characterization of the submarine disposal of a Bayer effluent (Gardanne alumina plant, southern France): I. Size distribution, chemical composition and settling rate of particles forming at the outfall

The submarine discharge of the high pH clarified Bayer effluent of the Gardanne alumina plant (Marseille region, France) leads to the formation of concretions at the outfall 324 m underwater and to a plume of white particles. The bulk chemical composition of the concretions has been determined by SF-ICP-MS. Mg and Al are the major elements measured with concentrations of a few hundred mg g−1. Ca and S are also found at concentrations in the range of mg g−1. Among the measured trace elements there is a specific interest in As and V because of environmental concerns pointed out by regulation authorities. Their concentrations are of tens to thousands μg g−1, respectively. Concentrations of the other elements are in the range of a few ng g−1 to few hundreds μg g−1. In order to constrain the dispersion of particles in the environment and to understand how chemical elements can be scavenged from or released to seawater, the size distribution of particles composing the concretions has been measured by settling rate experiments and, for each size class of particles, their chemical composition has been determined. For example, As and V are mainly associated to particles with mean diameters between 15.6 and 63 μm and settling rates around 96 m d−1. Overall, all the main elements (Mg, Al, Ca, S) composing concretions are associated to this size class of particles which represents 53–60% of the total concretion mass.

Failure Analysis of Hydraulic Cylinder Bolt on Turntable Vibrating Compactor in Aluminum Processing Plant

The aluminum and its alloy have several characteristics i.e. relatively low density, high electrical and thermal conductivity and also good in corrosion resitance. The molding process of green anode blocks at an aluminum plant is carried out by an anode forming system. In this system, there is a printer called as turntable vibrating compactor or referred to as a ‘shaking machine’. During 55 seconds of anode block compaction, the fluctuating stress would be received by hydraulic cylinder bolt due to vibrations of the turntable vibrating compactor. Fluctuating stress that works continuously on the bolt can increase the tendency of failure. This paper aims to find out the causing factors and alternative solution for failure of the hydraulic cylinder bolt. To determine the cause of failure, several methods are carried out, i.e. fractography investigation, metallography examination according to ASTM E3-95, hardness testing according to ASTM E92-17 and tensile testing according to ASTM E8/E8M-16a. Fractography investigation show the failure mode of low cycle fatigue due to the application of high nominal stress. This is indicated by the presence of ratchet, beach mark, river mark and shear lip. The short life of the bolt due to the hardness and strength of the bolt after undergoing the heat treatment process Q + T cannot increase its endurance limit.

Applying Capability Indices with Moving Average and Range Control Charts to Evaluate a Product in a Local Aluminum Plant

Applying Capability Indices with Moving Average and Range Control Charts to Evaluate a Product in a Local Aluminum Plant

Investigation of The Effects of Red Mud Addition on The Properties of Ceramic Wall Tile Body

Endüstriyel atıkların depolanması ve bertaraf edilmesi çevresel etki açısından en önemli problemlerden birisidir. Bu atıkların yeniden kullanılması hem çevrenin korunması açısından hem de alternatif hammadde potansiyellerinden dolayı diğer sanayi dallarının ilgisini çekmektedir. Özellikle de seramik sektöründe giderek artan hammadde maliyetleri ve azalan hammadde kaynakları bu atıkların değerlendirilmesinin önemini artırmaktadır. Bu çalışmada, Konya Seydişehir Alüminyum tesislerinin atığı olan kırmızı çamur alternatif bir hammadde kaynağı olarak kullanılmıştır. Yapılan çalışmada seramik duvar karosu reçetelerinde maksimum % 30 oranında kaolin yerine kırmızı çamur ve kalsit yerinede mermer tozu kullanılmıştır. Numuneler 1130 ° C de 60 dakika süre ile laboratuar koşullarında pişirilmiştir. Numunelerin pişme küçülmesi, su emme ve eğme dayanımları gibi teknolojik özelliklerinin yanı sıra sinterleme ve mikroyapı analizleri de araştırılmıştır. Yapılan testler sonucunda kırmızı çamur ilaveli bünyelerin pişme ve ham mukavemet değerleri artmıştır. Ayrıca herhangi bir pigment ilavesi olmadan sadece kırmızı çamur ilavesi ile kırmızı renkli bünyeler elde edilmiştir.

The benefits and challenges of a continuous improvement area in a manufacturing plant

A área de Melhoria Contínua é uma parte da empresa que busca suportar a implementação e execução de tarefasvoltadas às melhorias dos processos, o que pode vir a gerar maior valor agregado nas linhas produtivas. Nesse contexto, oobjetivo desse trabalho foi identificar os benefícios que a área de Melhoria Contínua fornece à produção da planta, bemcomo os principais desafios que enfrenta durante a aplicação do seu programa em todos os níveis de uma unidade de fabricaçãode bobinas de alumínio. A metodologia utilizada para atingir essa meta foi composta por entrevistas qualitativas com24 profissionais da empresa estudada, incluindo líderes de área, técnicos mecânicos, técnicos elétricos e líderes de primeira,segunda e terceira camadas, e da análise dos dados a partir do confronto com a literatura. Os principais resultados do trabalhoindicaram que os benefícios que a área de Melhoria Contínua fornece à produção da planta são compostos pela reduçãodos desperdícios, capacitação da força de trabalho e pelo desdobramento dos objetivos corporativos em objetivos tangíveispara a planta. Quanto aos principais desafios que enfrentaram durante a aplicação de seus programas, eles se relacionaramcom pessoas que não estão dispostas a mudar a forma que executam seus trabalhos e em encontrar a melhor forma de secomunicar com os envolvidos no programa.

The accumulation of fluoride by leaves of woody plants growing in the area of sanitary protection zones in the industrial region of Zaporizhzhya

Abstract Vegetation serves as a universal filter that is capable of protecting the environment from pollution by industrial emissions given the availability of appropriate technical facilities. The aim of this study is to determine the ability of leaves of various species of woody plants growing in the area of sanitary protection zones to accumulate fluorine and to establish the most informative indicators of environmental pollution by its compounds. The object of the study was the species of woody plants growing in the area of protective plantations of a number of enterprises of Zaporizhzhya: Zaporizhzhya Titanium & Magnesium Combine, Zaporizhzhya Aluminium Plant PJSC, Zaporizhzhya Abrasive Plant PJSC, Zaporizhstal PJSC, ‘Zaporizhcoke’ PJSC (KOKS), Zaporizhzhya Ferroalloy Plant PJSC, Zaporizhvohnetryv (‘Vohnetryv’) PJSC, PrJSC ‘Ukrgrafit’ and Zaporizhtransformator PJSC. Under the conditions of sanitary protection zones of enterprises the leaves of woody plants accumulate significantly more fluoride compared to the control specimens. We have established that a gradual accumulation of the element occurs during the vegetation period being the most intense in young leaves. In senescent leaves, the activity of its accumulation begins to diminish. The maximum amount of fluoride was detected by us at the end of the vegetation period. Its highest concentration was found in the leaves of woody plants growing in the forest belt near the Zaporizhzhya Aluminium Plant. According to the level of accumulation of the said phytotoxicant in the leaves of plants growing in the area of sanitary protection zones, industrial enterprises of Zaporizhzhya may be ranked as follows: Zaporizhzhya Aluminium Plant PJSC > Zaporizhzhya Ferroalloy Plant PJSC ≥ ‘Zaporizhcoke’ PJSC > Zaporizhstal PJSC > Zaporizhvohnetryv (‘Vohnetryv’) PJSC > ‘Ukrgrafit’ PJSC> Zaporizhzhya Abrasive Plant PJSC > Zaporizhzhya Titanium & Magnesium Combine > Zaporizhtransformator PJSC. The largest amount of fluorine accumulated by the leaves can be attributed to such tree species as: Catalpa bignonioides, Ailanthus altissima, Acer platanoides, Populus nigra, Armeniaca vulgaris, Tilia cordata, Acer pseudoplatanus, Platanus orientalis, which is a distinguishing characteristic of the sanitary protection zones of various enterprises in the city of Zaporizhzhya. Variations of fluorine accumulation in different experimental plots for the same species of woody plants are expressed in quantitative terms. These plants are capable of being the most efficient at purifying the atmospheric air from gaseous fluoride compounds. The highest coefficient of relative accumulation of fluorine in the leaves is found in the following species of woody plants: Catalpa bignonioides, Ailan-thus altissima, Acer platanoides, Populus nigra, Armeniaca vulgaris, Tilia cordata, Acer pseudoplatanus, Platanus orientalis, thus they have a potential to be considered for use as phytoindicators of environmental pollution by the fluorine compounds. The aforementioned coefficient appears to be the lowest in the following species: Morus alba, Elaeagnus angustifolia, Juglans regia and Fraxinus lanceolata.

Thermodynamics, kinetics, and isotherms for phenol removal from wastewater using red mud

Abstract The phenol removal through adsorption using industrial waste has been studied. The red mud generated as waste in the aluminum plants was used in this research. The surface characterizations of red mud were assessed. The batch experiment was investigated with pH (2–12), adsorption period (120–600 min), phenol content (40–200 mg/L), adsorbent dose (2–7 g/L), and temperature (30–50 °C). At the optimum operating condition, the percentage of phenol removal was 87.5%. The pseudo-second-order kinetic model (r2 = 0.98625–0.99994) fitted better than the pseudo-first-order kinetic model. The Freundlich isotherm model was best fitted (r2 = 0.99734–0.99955) among Langmuir, Dubinin–Radushkevich (D-R), and Temkin isotherms. The Langmuir monolayer adsorption capacity was 49.30966 mg/g at 30 °C. The adsorption mechanisms were supported by Reichenberg, Fick, Elovich, Furusawa, and Smith and Boyd models (r2 > 0.8). The thermodynamics suggested endothermic, random, and spontaneous adsorption above 50 °C. The scale-up design using the Langmuir isotherm, and the disposal of used adsorbent after incineration, was established in this study. The research concludes that the red mud generated from the aluminum plant can be used to remove the phenol from wastewater.

Trade-offs in the process of enrichment of tree plantations in sanitary protection zones of enterprises regarding the peculiarities of potential accumulation of toxicants in the leaves of trees

Plants serve as a versatile filter that is capable of purifying the atmospheric air from various toxic substances. In this study we investigate the green areas of sanitary protection zones of PrJSC Ukrgrafit and Zaporizhzhya Aluminium Plant PJSC industrial enterprises in the city of Zaporizhzhya, Ukraine. The forest stands growing in these zones were surveyed using the route method and the level of accumulation of water-soluble phenolic compounds, sulfur and fluorine in the leaves of plants was determined. On the basis of the data obtained during our investigation, compromise plans were proposed for enriching the tree flora growing in the area of green spaces of sanitary protection zones of PrJSC Ukrgrafit and Zaporizhzhya Aluminium Plant PJSC industrial enterprises, taking into account both their current and potential gas absorption capacity. Taking into account the environmental conditions and the natural resistance of plants, as far as protective plantations of the PrJSC Ukrgrafit enterprise and the species composition of forest belts of the Zaporizhzhya Aluminium Plant PJSC, the second and the fifth variants in the first case, as well as the fifth and the sixth variants in the second case, were determined as being the best options available for the purpose of tree flora enrichment.

Fluorine enrichment of vegetables and soil around an abandoned aluminium plant and its risk to human health.

In the process of electrolytic aluminium production, a large amount of fluoride is deposited into the surrounding environment. The growth of crops within these areas creates a state of high stress in plants that can easily result in excessive fluorine enrichment in agricultural products, which in turn poses a health threat to humans via the food chain. However, it is not clear what the degree of influence is or how long the impacts of fluorides in soil and agricultural products last for. In this study, 122 vegetable species and 36 surface soil samples were collected within 10km of an aluminium plant that had been abandoned for five years. The single factor index and the geological accumulation index methods were used to evaluate the degree of fluorine pollution in vegetables and soil within the study area. The hazard index and the hazard quotient were used to assess vegetable and soil health risks, respectively. The results showed that the fluorine content of 89.26% of agricultural products exceeded the Chinese Maximum Levels of Contaminants in Foods and was higher than in other regions, indicating that the emissions of fluoride from the aluminium plant still had a significant effect on fluorine accumulation in vegetables. The total fluorine (Ft) content in the surrounding surface soil (average value 1328.32mgkg-1) was similar to the soil fluorine background in the nearby uncontaminated settlement area, but the soil water-soluble fluorine (Fw) was very high, indicating that the fluorine pollutants emitted from the aluminium plant had gradually been diluted by the high background of the original soil, but the solubility of these pollutants was higher (average 15.00mgkg-1) and would continue to threaten the safety of agricultural products in this region. Within 1km of the abandoned aluminium plant, the degree of fluorine enrichment in vegetables, and Ft and Fw in soil were significantly higher than other ranges, indicating that this was the main fluoride deposit area. Based on the HI and HQ evaluation, vegetables and ground dust around the aluminium plant still had high non-carcinogenic risks for children, even though it has been abandoned for more than five years.

Opportunities for sustainability improvement in aluminum industry

AbstractThe aluminum consumption in India of 2.5 kg per capita is way below the global average of 11 kg per capita. In the future, India will require additional annual consumption of 16 million tons of aluminum. Due to the energy‐intensive nature of aluminum production coupled with its projected growth, there are sustainability concerns for this industrial sector. This paper examines some opportunities available for sustainability improvement in an existing aluminum plant using coal‐based electricity. An industrial sustainability index (ISI), as previously developed by the authors, is here to quantitatively evaluate the magnitude of sustainability improvement through a natural gas‐based combined cycle (NGCC) power generation. Two modes of sustainability improvement are examined: (a) NGCC with surplus power generation and (b) NGCC with doubling of production capacity. It is observed that the ISI values can be increased by 5 to 6 times through the above modes, as compared to the existing model. The investment required for such sustainability improvement is expected to be less than that required for setting up a totally new plant. The direct carbon emissions for the existing plant are nearly 6.4% of the total carbon emissions, which may be eliminated by adopting new smelting technology now available, with the further possibility of sustainability improvement.

Изучение биоиндикационного значения беспозвоночных животных серо-бурых почв загрязненных отходами алюминиевого и трубопрокатного заводов г. Сумгаита

Soil animals are a very important biological factor in soil formation and the formation of high soil fertility. The soil is abundantly inhabited by numerous representatives of different groups of animals, for which it represents not only the habitat but also the result of their combined activity. Changes in soil invertebrate complexes are important indicators of industrial pollution. A study conducted on a natural cenosis grey–brown soils under wormwood–ephemeral vegetation contaminated waste Aluminum Plant and Tube–rolling Mill of Sumgait. Our purpose is to carry out soil and zoological research (as well as samples taken for microbiological analyzes) and on basis collected material and subsequent detection of a theoretical analysis of the major dominant groups bioindicators. Soil and zoological studies will help the future identify invertebrates that are most resistant to pollution factors, which can also be used as bioindicators of technologically polluted soils.

Scenario-based DEA assessment of energy-saving technological combinations in aluminum industry

This study deals with technology evaluation by employing the data envelopment analysis (DEA) methodologies from a life-cycle analysis (LCA) perspective. Aluminum production is associated with high electricity consumption. Thus, the environmental pressures of the whole production chain largely rely on the electricity generation process. This is particularly true for China, because coal-fired power generation dominates China’s electricity supply. Many of aluminum plants in China consume electricity which is directly supplied by coal-fired plants. Given these facts, LCA perspective in this study is believed to be of distinctive significance. Therefore, this paper discusses the process requiring high-energy consumption and causing high pollution from the LCA perspective and combines data envelopment analysis with LCA to evaluate and select energy-saving technological routes throughout for the complete supply chain. In total, 16 technological combinations are considered, and three models are established for different sets of efficiency indicators: energy performance indicator, energy performance indicator with undesirable output, and total performance indicator. Moreover, four scenarios with different policy considerations are designed: baseline scenario, subsidy scenario, low-carbon-price scenario, and high-carbon-price scenario. The results show that upon only considering energy input and output at the same price, a power generation mode has the greatest impact on energy consumption. After considering undesirable output, such as pollutant emissions, the technological routes including coal-fired power generation have the worst performance. Considering all inputs and outputs with the same price, the most crucial factor affecting efficiency is cost, followed by anode; subsidies have a low effect. For the four scenarios, two technological routes including a biomass-integrated gasification combined cycle power generation and inert anode rank in the top 50% decision-making units with three efficiency indices. This paper proposes an effective decision-making method for evaluating and selecting energy-saving technology routes for the aluminum industry, which can be easily applied to other sectors with similar characteristics. This provides a generic framework for a profound analysis to promote clean production and environmental sustainability.

Εnergy-exergy analysis of ultra-supercritical biomass-fuelled steam power plants for industrial CHP, district heating and cooling

The use of biomass in combined heat and power (CHP) plants with district heating and cooling is necessary for achieving decarbonization targets. While in traditional biomass plants steam temperature is below 520 °C, new developments can lead to ultra-supercritical (USC) designs with steam temperatures of 600 °C. The present study investigates the performance of such plants for covering the heat demands of the aluminum and pulp and paper industrial processes, while also producing district heating and cooling. Plant performance is assessed through sensitivity analyses covering a wide range of heat demand scenarios. In the electricity-only scenarios, the electric and exergetic electric efficiencies of the aluminum/pulp and paper plants are 43.45/44.22% and 38.93/39.62%, respectively. In the CHP scenario, when the heat demand is maximized, the electric, exergetic electric, CHP and exergetic CHP efficiencies of the aluminum/pulp and paper plants are 21.81%/34.32%, 19.54%/31.70%, 92.50%/86.76% and 39.43%/39.01%, respectively. With the integration of cooling, the electric and CCHP efficiencies of the aluminum plant are 21.60% and 89.23%, respectively. Most of the exergy is destroyed during the combustion and steam generation processes, corresponding to 67–70% and 13–16% of the total exergy destruction, respectively.

Energy intensity in the EU chemical industry halved over a 26-year period

•This study provides a novel analysis of energy and technology use in Vietnam’s aluminum industry. Vietnam has the world’s fourth largest bauxite reserves, and is developing a full aluminum supply chain, from bauxite mining to aluminum smelting. Aluminum production is one of the most energy-intensive industrial processes, yet Vietnam has relatively few domestic energy resources, and no data on energy use in its aluminum industry. This paper quantifies energy intensity in each phase of aluminum production in Vietnam in comparison to global estimates. The paper finds that Vietnam’s aluminum production is more energy intensive than the global average, driven by high energy intensity in the alumina production phase. The paper identifies broad barriers to industrial energy efficiency in Vietnam and similar countries, and how these challenges can be incorporated in future research. Potential retrofit technologies are identified for Vietnam’s alumina plants, including cost and energy saving potential for each technology. Analysis of net present value, including policy scenario analysis, indicates that some of these retrofit technologies are promising investments in the near term, with simple payback periods of less than ten years for four out of the five technologies identified. The energy footprint of Vietnam’s aluminum industry is an important consideration for policymakers in Vietnam, given Vietnam’s need for energy resources, and promoting efficient operation of Vietnam’s aluminum industry will require additional technology and policy changes. This research demonstrates a mixed-methods approach that can be applied to address the challenges data-constrained planners face in developing energy-intensive industries worldwide.

Оценка компонентов нижних ярусов растительного покрова в антропогенно нарушенных березняках Красноярской лесостепи

The vegetation cover characteristics of anthropogenically disturbed birch stands of Krasnoyarsk forest-steppe are studied. The research purpose is to study the current state of under story vegetation cover of the birch stands, which have been exposed to recreational and anthropogenic impacts for a long time, as well as to assess the degree and nature of its changeover the 12-year period since the last research. The studies were carried out on the sample plots laid out in mixed herbs birch stands. Cenosises are characterized by V–VI age classes,II–IV quality classes, and 0.6–0.9 density of stocking. The birch stands are located in the main transfer of Krasnoyarsk industrial emissions. Phytocenoses were under significant anthropogenic and recreational impact for a long time. At each facility, 30 sites (1 m2 each) were laid, where species composition, horizontal and vertical structure, projective cover and occurrence of undergrowth and forest live cover species were assessed. The comparative analysis of floristic lists was performed using the Sorensen-Czekanowski coefficient (Ksc). The degree of species diversity was estimated by using the Shannon index; the degree of recreational transformation – synanthropization index. Cuttings were taken from 10 sites (20 × 25 cm each) for recording the phytomass stock of forest live cover on each sample area. Plants were cut off at the litter level, sorted by species, dried and weighed. Rating scales of digression were used to study the recreation influence. The degree of anthropogenic impact was determined by the content of toxic ingredients in plants of living ground cover. It is found that the toxic elements concentration in plants does not reach excessive values at which homeostasis disturbance happens. It was concluded that the changes in vegetation cover observed in 2017 in relation to the state of 2005 are more due to recreational than anthropogenic impact; which changed due to the introduction of a new technology at the JSC “RUSAL Krasnoyarsk Aluminum Plant”, which made it possible to reduce toxic industrialemissions. According to the study results, the species composition of the undergrowth and forest live cover was determined, the features of its change over a 12-year period were revealed. It is noted that species diversity has decreased and the proportion of synanthropic species has increased across all plots. Total forest live cover phytomass and individual species phytomass are determined at each plot. The regularities of change in different species contribution to the total stock of phytomass, depending on recreational impact changes, were identified. The ground cover recreational digression stages are determined by analyzing the changes in species diversity, the quantitative ratio of ecological-cenotic groups, the structure and the absolute value of phytomass. For citation: Goncharova I.A., Skripal’shchikova L.N., Barchenkov A.P., Shushpanov A.S. Understory Vegetation Cover Components Assessment in Anthropogenically DisturbedBirch Stands of Krasnoyarsk Forest-Steppe. Lesnoy Zhurnal [Russian Forestry Journal], 2020, no. 1, pp. 75–87. DOI: 10.37482/0536-1036-2020-1-75-87 Funding: The study was carried out within the framework of the basic research projects of the Sukachev Institute of Forest SB RAS “Biodiversity of Indigenous Coniferous and Derivative Forest Ecosystems” (No. 0356-2016-0301) and “Dynamics of Siberian Forests in a Changing Climate. Monitoring of the Living State, Productivity and Ranges of the MainForest-Forming Species of Woody Plants” (No. 0356-2018-0739).

MATHEMATICAL MODELING OF THE DEVELOPMENT OF CHRONIC FLUORINE INTOXICATION IN ALUMINIUM INDUSTRY WORKERS

Introduction. Chronic fluorine intoxication prevails among the newly discovered occupational diseases in aluminum industry workers. Mathematical modeling is one of the helpful tools in ensuring better risk management with respect to the development of occupational fluorosis. Objective. Developing a logistic regression model predicting a probability of occupational fluorosis development in an occupational staff of aluminum plants in order to suggest adequate prophylactic strategies. Material and methods. A logistic regression model predicting a probability of the development of occupational fluorosis in aluminum industry workers of the Sverdlovsk region was constructed. The model embraced the results of a univariate analysis conducted with respect to major occupational exposures and health characteristics of 201 workers. Results. Six major factors were identified as being predictive of occupational fluorosis development in aluminum industry workers: age (fluorosis risk increases with age); type 2 diabetes mellitus; atrophic gastritis; kidney cysts; X-ray examination data (fluorosis risk increases with the stage as determined by X-ray); the hydro fluoride concentration increases by more than 2 occupational exposure limits. The developed model was verified by clinical cases and showed a high predictive ability (86.2 %). Both sensitivity (true positive rate) and specificity (true negative rate) of the model amounted to 86.2 %. Conclusion. By multivariate analysis the significant, mutually independent factors were identified, their combination being associated with chronic fluorine intoxication in an occupational staff of aluminum plants. The developed mathematical model has a high predictive ability and can be recommended as a sure tool to forecast the course of occupational fluorosis development in the workers at the aluminum industry.

ВЛИЯНИЕ ПОВЫШЕННОГО ТЕХНОГЕННОГО ЗАГРЯЗНЕНИЯ ОКРУЖАЮЩЕЙ СРЕДЫ НА ЗДОРОВЬЕ И ДЕМОГРАФИЧЕСКОЕ ПОВЕДЕНИЕ ЖИТЕЛЕЙ г. КРАСНОЯРСК

The article considers negative trends in demographic processes associated with the impact of the environment on the life and health of the Krasnoyarsk city population. Methodological features of the study of the research subject are discussed, as well as the elaboration of the problem within the framework of specific sciences is analyzed. To what extent does the habitat with an increased level of technogenic pollution affect the subjective attitudes of residents, their needs, opinions, plans, and decision-making regarding demographic aspects of life? The presented results of expert interviews with specialists in the field of environmental protection and public health were taken by the author in November 2020. They indicate a truly deplorable situation in one of the major industrialized cities of Russia, Krasnoyarsk. The main pollutants are supposed to be transport, the RUSAL aluminum plant, the private sector with coal-fired heating and three coal-fired power plants. The Krasnoyarsk hydroelectric power station has a negative impact as well. The experts point to the obvious insufficiency of studying the problem of the impact on the demographic indicators and behavior of citizens, which is associated with the lack of open information about the level of the Krasnoyarsk urban environment pollution and specialized research in this direction.

The content of water-soluble phenolic compounds in the leaves of woody plants growing in the area of sanitary protection zones of enterprises of the industrial region of Zaporizhzhya

The article presents the results of studying the accumulation of water-soluble phenolic compounds in the leaves of woody plants growing in the area of sanitary protection zones of a number of enterprises of Zaporizhzhya: Zaporizhzhya Titanium & Magnesium Combine, Zaporizhzhya Aluminium Plant, Zaporizhzhya Abrasive Plant, Zaporizhstal, Zaporizhcoke, Zaporizhzhya Ferroalloy Plant, Zaporizhvohnetryv, Ukrgrafit and Zaporizhtransformator. The concentration of phenolic compounds was found to be significantly higher under the technogenic conditions compared to the relatively "clean" area. Their highest concentration was found in the leaves of woody plants growing in the forest belt near the Zaporizhcoke plant. For the level of accumulation in the organs of assimilation of trees, and thereby for the degree of air pollution by the phenolic compounds, enterprises can be ranked as follows: Zaporizhcoke > Zaporizhstal ≥ Zaporizhzhya Ferroalloy Plant > Zaporizhvohnetryv > Ukrgrafit > Zaporizhzhya Aluminium Plant > Zaporizhzhya Titanium & Magnesium Combine > Zaporizhzhya Abrasive Plant > Zaporizhtransformator. Depending on the level of accumulation of phenolic compounds in the leaves, the plants have been divided into three groups. The largest amount of the pollutant, compared to the other species of woody plants, is being accumulated by the leaves of the following species: Ailanthus altissima, Betula pendula, Juglans regia, Populus alba, Populus nigra, Populus piramidalis, Populus simonii, Elaeagnus angustifolia, and the least amount – by Morus alba, Robinia pseudoacacia, Tilia cordata, Ulmus carpinifolia, Armeniaca vulgaris, Fraxinus lanceolata. The following species occupy the intermediate position between the two groups: Acer negundo, Acer platanoides, Aesculus hippocastanum, Catalpa bignonioides, Salix alba, Ulmus laevis. The tree species that can be characterized by their capacity to accumulate the highest concentration of water-soluble phenolic compounds may be recommended for the purpose of purification of atmospheric air. The following plant species, which turned to be the most sensitive indicators of air pollution, have been listed in a descending order according to the value of the coefficient of relative accumulation of phenolic compounds. Such species include Betula pendula, Catalpa bignonioides, Elaeagnus angustifolia, Ailanthus altissima, Populus simonii, Acer negundo, Ulmus laevis and Fraxinus lanceolata.

Reductive Smelting of Neutralized Red Mud for Iron Recovery and Produced Pig Iron for Heat-Resistant Castings

The chemical and mineral composition of the red mud from the Ural Aluminum Plant were studied by XRF, XRD, and Mössbauer spectroscopy. Experiments on reductive smelting of red mud were carried out in a range of temperatures (1650–1750 °C) to recover iron from the aluminum production waste with maximum efficiency. It was found that it is possible to obtain pig iron with a high content of titanium, phosphorus, and vanadium, and low sulfur content. The efficiency of iron recovery at 1750 °C was found to be around 98%. Thermodynamic calculations were carried out to assist in finding the optimal conditions for the process (e.g., carbon content, furnace temperature, slag liquidus temperature). It was also found that the pig iron phase obtained at 1650 to 1700 °C is not separated from the slag phase into ingot compared with the sample obtained at 1750 °C. Pig iron obtained at 1750 °C can be used to produce molds for the steel-casting equipment.

Analysis of Technological Issues, Related to Processing of Alunite at Ganja Alumina Plant (GAP), and Ways of Their Solving

In 1965, the Ganja Alumina plant (GAP) started implementing an alkaline reduction technology for processing of alunite ore on an industrial scale. Technological deficiencies, together with design errors, led to unprofitable production. Since the plant was established, studies have been conducted to eliminate deficiencies in the reduction process, through alkaline technology and hardware design. A “reversed” scheme was developed for hydrochemical processing of alunite restored with the conversion of sodium sulphates using a KOH solution. Despite the elimination of several shortcomings in alkaline reduction technology, certain drawbacks remained, in particular: 1) significant emission of gas and dust from the kilns of fluidized bed furnace during roasting and recovery; 2) insufficient time for recovery of alunite powder, which complicates and worsens the technological and economic aspects of the process; 3) passivation of alumina in the roasting and reduction processes; 4) low yield alumina yield in the commercial product (≤ 75%); and 5) a significant amount of solid waste: 5 tonnes of red sludge per 1 tonne of AL2O3, and errors. As a result, the alunite ore processing line ceased production in 1992 and has not operated since.
 
 This article is devoted to the development of new technologies and the improvement of a new potash-alkaline method and new soda-alkaline technology for processing alunite ores. The replacement of potash with soda (sodium carbonate), using new soda-alkaline technology, is proposed. Processing of solution from the first leach with sodium sulphate by conversion with KCl leads to production of K2SO4 and NaCl. Use of the soda-alkaline technology allowed us to obtain the same products as with potash-alkaline technology, with an additional product – table salt. The fluidized bed furnace was replaced by a new type of kiln.