Smelting Complex Bor Research Articles

Air Quality Benefits From Implementing Best Available Techniques in Copper Mining and Smelting Complex Bor (Serbia)

Since 2016, the impact of the best available techniques (BAT) on air quality in Bor is significant. Its performance is presented by the air quality assessment with respect to the average annual sulfur dioxide (SO2) emitted concentrations and the total SO2 volume emitted per year from the smelter and sulfuric acid plant, relative to the quantity of processed concentrate in the period when production was conducted with the old technology, in 2013. Air quality in Bor was categorized as category III, i.e., the air was heavily polluted due to the exceeded tolerance of SO2 values. In the agglomeration Bor, during 2016/2017, air was of the category I, i.e., clean or slightly polluted air. The data illustrated that the temporal (yearly) variation of SO2 concentration was more influenced by human-related factors, especially by secondary industry share, as SO2 is mainly produced and discharged in the process of industrial production. The spatial variation of such concentration was more affected by meteorological indicators, especially by wind direction. In the period of the new technology, a significantly greater volume of concentrate was processed and a considerably larger quantity of cathode copper produced, and at the same time, total volume of emitted SO2 and measured heavy metals (lead-Pb, arsenic-As, cadmium-Cd, and nickel-Ni) was substantially reduced.

Treatment of the acidic effluent from a copper smelter by flotation tailings

Since commissioning in 1961, the copper mine Majdanpek, a part of the Mining and Smelting Complex Bor (RTB Bor), produced approximately 378 million tons of flotation tailings. Semi-quantitative mineralogical analysis of the flotation tailings revealed significant content of carbonate minerals (approximately 20-25 %), indicating high acid neutralization capacity. Also, approximately 70 % of copper is in the form of the oxide mineral cuprite (Cu2O). Copper can be easily leached from cuprite by using sulphuric acid. The RTB Bor copper smelter generates 8.7 m3h-1 of extremely acidic waste effluent (142.4 kgm-3 of sulphuric acid, pH -0.464) with relatively high concentrations of dissolved metals and metalloids (Cu, Fe, Zn, Pb and As). The effluent is currently treated with hydrated lime. The present study focused on application of flotation tailings as a neutralizing agent for acidic effluents. Laboratory experiments followed by computer simulation of the industrial process showed that 99% of the acid can be neutralized with flotation tailings in a series of six reactors resulting in the final copper concentration of 1.55 gL-1. Benefits of the proposed process are: lower environmental impact of the process and reduced costs of neutralization of the acidic effluent from the copper smelter.

The effect of multiple contamination of soil on LMW and MMW PAHs accumulation in the roots of Rubus fruticosus L. naturally growing near The Copper Mining and Smelting Complex Bor (East Serbia).

Samples of roots and spatial soils of native Rubus fruticosus L. were collected from the spots positioned at different distances from the copper smelter and city heating plants in the industrial zone of the town of Bor (Serbia) and subjected to chemical analyses in order to determine the content of several heavy metals, and 15 priority polycyclic aromatic hydrocarbons (PAHs). In this study, the results for 9 low and medium molecular weight PAHs (LMW and MMW PAHs) are represented and processed using the calculation of bio-concentration factors and statistical methods such as hierarchical cluster analysis and Pearson's correlation study with the aim of investigating the plant capabilities for their uptake from the soil and later accumulation into the root tissue, under the hostile circumstances of multiple contamination. The obtained data revealed different accumulation rates for the investigated PAHs and showed that in several cases, the contents of root PAHs were under the strong influence of present contaminants such as soil copper and some soil PAHs, indicating at the same time that R. fruticosus can regulate the processes of LMW and MMW PAHs extraction/accumulation using different mechanisms, depending on the existing environmental circumstances. The used mechanisms could be exploited in phytoremediation methods based not only on the extraction and concentration of PAHs in plant roots but also on PAH degradation or stabilization in the soil. Also, the results of this study confirmed that, except in the case of naphthalene and fluoranthene, there was no PAH pollution, which originated solely from the industrial zone.

Bioaccumulation of HMW PAHs in the roots of wild blackberry from the Bor region (Serbia): Phytoremediation and biomonitoring aspects

In this work, the samples of roots and soils from the rooting zone of wild blackberry were collected from the urban-industrial and rural locations near “The Copper Mining and Smelting Complex Bor” (Serbia); they were analyzed by gas chromatographic-mass spectrometric method to determine the content of high-molecular weight polycyclic aromatic hydrocarbons (HMW PAHs). The obtained results were further processed using bio-concentration factor, Pearson's correlation study and hierarchical cluster analysis with the aim of investigating if they may be in favor of wild blackberry as a suitable plant for biomonitoring or phytoremediation purposes. In spite of the fact that numerous complex factors can affect the assimilation and accumulation of PAHs in plants, the obtained data expressed clearly many interesting specifics related to HMW PAH accumulation in roots of wild blackberry that naturally grows in an area, which is heavily polluted by heavy metals. The accumulation of individual PAH compounds in plant roots was at different level. The most abundant compound in all plant samples was benzo[a]pyrene and based on the results obtained for this environmental indicator of carcinogenic PAHs, it was possible to make several central conclusions: wild blackberry showed an excellent potential for its extraction from the soil and further accumulation in root tissues which indicate that this plant species may be applied in phytoremediation procedures based on mechanisms such as phytoextraction/phytoaccumulation in roots; phytostabilization and rhizodegradation are also possible as remediation mechanisms; utilization of plant roots in soil monitoring is possible but in this case, only the combination with soil data can provide correct information.

Impact of administrative measures on electrical energy costs in copper production

The Mining and Smelting Complex Bor (RTB) is one of the biggest electrical energy consumers in Serbia, with costs that exceed 3 million USD per month, or between 30 and 40 million USD per year. A complex technological process of copper production comprises mining, concentrate production (flotation), smelting and electrolytic refining. In all these stages a large amount of energy is consumed. The electricity is supplied from the power plants using 5 substations: two of them located in Bor, and the remaining three in Majdanpek. The conditions for delivery and billing of the electrical energy were defined by the contract with the supplier. The methods of billing (calculation) the electrical energy costs were changed several times in the previous 25 years. Although the consumed energy is the largest part of the overall costs, there were also some indirect costs affecting the final monthly price. It is clear that even a minor percentage decrease of costs can lead to substantial savings in the total amount. Hence, different technological and organizational activities were undertaken to reduce these costs. The paper presents primarily the effects of administrative measures on the amount of total electrical energy costs in copper production.

Phytoremediation potential of the grapevine in regard to lithium

In this paper, the phytoremediation potential of the grapevine (Vitis vinifera) cv Tamjanika in regard to lithium (Li) was investigated using chemical and statistical analysis, as well as the calculation of bioaccumulation and enrichment factors. Plant and soil material was collected from the Bor region. Based on the obtained results it can be concluded that plants of the grapevine cv Tamjanika acted as exluders of Li which may candidate this plant species as a suitable choice for phytostabilization purposes. Its application in phytoextraction could not be estimated due to the fact that detected Li concentrations in the aboveground parts could not be considered as a real bioaccumulation. However, based on Li contents in unwashed aboveground parts (especially in leaves) it was possible to detect that particular part of Li load which came from the atmosphere, i.e. from the industrial facilities of the Copper Mining and Smelting Complex Bor which may point to their biomonitoring potential.

Plant parts of the apple tree (Malus spp.) as possible indicators of heavy metal pollution

The content of Cu, Zn, Pb, As, Cd, and Ni was determined by ICP-OES in spatial soil and parts (root, branches, leaves, and fruit) of the apple tree (Malus spp.) from polluted sites near The Mining and Smelting Complex Bor (Serbia). The aim of this study was to examine if the obtained results can be used for biomonitoring purposes. Data recorded in plant parts, especially leaves, gave very useful information about the environmental state of the Bor region. Conveniently, these data described well the capability of investigated plant species to assimilate and tolerate severely high concentrations of heavy metals in its tissues, which may further allow the possibility for utilization of the apple tree for phytostabilization.

Iron content in the fruits of the grapevines and peach trees growing near the mining and smelting complex Bor, east Serbia

The samples of fruits of the grapevine (Vitis vinifera, cultivar Tamjanika) and the peach tree (Prunus persica L. Batech) from the Bor region were analyzed using an ICP-OES to determine the content of iron (Fe). This was done in order to assess possible health risks related to this essential element; the region of Bor?s municipality is known as one of the most polluted areas in Serbia. The content of Fe in unwashed grapes seems not to be affected by the mining/metallurgical activities, as it was either in the normal concentration range or was at even lower than critical deficiency concentration in plants (21.8-98 mg/kg). The level of Fe in the samples of peaches ranged from 62.4 to 1418 mg/kg, which is much higher than that in grape samples and in one case, even higher than the phytotoxic threshold. The values of the enrichment factor (EF) were lower than 2 in the case of grape samples, while for peach samples, these values ranged from rather low (0.99) to extremely high (22.66). Based on the herein obtained results, in the region of Bor, it seems that the cultivation of grapevine should be favored over the cultivation of peach trees.

Assessment of the quality of polluted areas based on the content of heavy metals in different organs of the grapevine (Vitis vinifera) cv Tamjanika.

In this study, the samples of the spatial soil and organs of the grapevine (Vitis vinifera) cultivar Tamjanika were collected from the selected zones near the Mining and Smelting Complex Bor (East Serbia). They were analyzed by ICP-OES to determine the content of Cu, Zn, Pb, As, Cd, and Ni with the aim of ascertaining if these data may help in the assessment and improvement of the quality of environment in polluted areas such as Bor and its surrounding area. The results obtained from the calculated biological and enrichment factors, as well as from the Pearson correlation study and hierarchical cluster analysis confirmed that very useful information is recorded in plant organs: root, stem, leaves, and fruit. Yet, when the atmospheric pollution is the sphere of interest, the most informative data are found in unwashed leaves. The results of this study indicated also that the investigated plant species has some highly effective strategies involved in tolerance to the stress induced by heavy metals, which makes it an excellent candidate for phytostabilization purposes. Planting of this grapevine cultivar can be recommended in all areas that are severely polluted with heavy metals.

10.5937/mmeb1403153j = Technological investigations of sulphide oxidation from flotation tailings in order to increase the degree of copper leaching

The off-balance resources present the environmental problem and potential resource for copper extraction. This paper presents the results obtained using different reagents for the process of sulphide form oxidation of copper from flotation tailings. For the investigation in this paper work, the samples of flotation tailings were taken from the Old Flotation Tailing Dump of the Mining and Smelting Complex Bor in Eastern Serbia. Experimental testing was carried out in order to increase the leaching degree of copper with addition of oxidants during leaching. Using the Fe 2(SO 4)3 as an oxidant, the achieved copper leaching degree was 76.8%. The effect of thermal destruction of sulfide copper from flotation tailings in the presence of concentrated sulfuric acid was also investigated. After leaching of calcine with water, the degree of copper leaching was attained of 92%. Solutions after leaching are suitable for the SX-EW process of obtaining the copper.

Investigating the Impacts of Winds on SO2 Concentrations in Bor, Serbia

Air pollution is one of the most important environmental problems in the town of Bor, situated in the eastern of Serbia. The main source of air pollution with sulphur dioxide, heavy metals and other toxic and carcinogenic elements present in particulate matter (PM) and aero sediments is the Copper Mining and Smelting Complex Bor. The distribution of air pollutants is mainly determined by the copper smelter operation mode, as well as by meteorological parameters such as wind speed and direction. While information on air pollution with heavy metals and carcinogenic elements in the form of PM has been monitored and reported for longer period, availability of data related to the relationship between air pollutants and meteorological parameters in the Republic of Serbia is still limited. In the present study, the relationships between daily mean concentrations of SO2 and the speed and wind direction were analysed. The analysis includes data collected in 2011 from the four monitoring stations (Park, Jugopetrol, Institute, and Brezonik) situated in a wider town area. Pearson correlation coefficients between daily average SO2 and daily average speed and direction of winds are calculated. High wind speed reduces SO2 concentration due to the dilution effect. Hence, correlations between SO2 and the speed and direction of winds at almost all monitoring stations were negative, with one exception (Jugopetrol). This could be explained by the fact that winds, blowing from the north-west (NW) direction, carry polluted air towards this station. Moderate negative correlation found between SO2 and wind direction at monitoring station Park. Generally, the observed correlations between SO2 and wind speed and direction are weak, due to frequent changes in SO2 emissions, wind speed and direction during the day.

Microbial diversity and isolation of multiple metal-tolerant bacteria from surface and underground pits within the copper mining and smelting complex Bor

The bacterial diversity of the surface and deep sediment of the Copper Mining and Smelting Complex Bor, Serbia, was investigated using culture-dependent and culture-independent approaches. Sequencing analysis of 16S rDNA libraries revealed greater bacterial diversity in the surface sediment of the mining complex (MS) in comparison to deeper mine sediment (MU). While in the MS sample members of seven different phylogenetic groups were detected, in the MU sample library representatives of only three different groups were detected. The use of a culture-dependent approach revealed the presence of only three bacterial groups in both samples: Actinobacteria, Firmicutes and Proteobacteria, while six isolates exhibiting the highest metal tolerance were members of Arthrobacter and Staphylococcus genera. The most promising isolate, MSI08, was able to grow in the presence of high concentrations of Cd2+ (535 μM), Ni2+(17 mM) and Cr6+ (38.5 mM) and as such this indigenous strain has potential in the bioremediation of the contaminated surrounds of the city of Bor.

Half a Century of Computing in the Serbian Copper Mining and Metallurgy Industry

The Copper Mining and Smelting Complex Bor (RTB Bor) in the Republic of Serbia has a long history of computer control and computer-aided data processing. Working within the confines of the Cold War era, RTB implemented and developed four generations of computers, becoming a major influence in the IT sector and the primary computer training resource in the region.

Metal concentrations in the soils and native plants surrounding the old flotation tailings pond of the Copper Mining and Smelting Complex Bor (Serbia)

In this study concentrations of metals in the native plants and soils surrounding the old flotation tailings pond of the copper mine were determined. It has been established that the soil is heavily contaminated with copper, iron and arsenic, the mean concentrations being 1585.6, 29,462.5 and 171.7 mg kg(-1) respectively. All the plants, except manganese, accumulated metallic elements in concentrations which were either in the range of critical and phytotoxic values (Pb and As) or higher (Zn), and even much higher (Cu and Fe) than these values. Otherwise, the accumulation of Mn, Pb and As was considerably lower than that of Cu, Fe and Zn. In most plants the accumulation of target metals was highest in the root. Several plant species showed high bioaccumulation and translocation factor values, which classify them into species for potential use in phytoextraction. The BCF and TF values determined in Prunus persica were 1.20 and 3.95 for Cu, 1.5 and 6.0 for Zn and 1.96 and 5.44 for Pb. In Saponaria officinalis these values were 2.53 and 1.27 for Zn, and in Juglans regia L. they were 8.76 and 17.75 for Zn. The translocation factor in most plants, for most metals, was higher than one, whereas the highest value was determined in Populus nigra for Zn, amounting to 17.8. Among several tolerant species, the most suitable ones for phytostabilization proved to be Robinia pseudoacacia L. for Zn and Verbascum phlomoides L., Saponaria officinalis and Centaurea jacea L. for Mn, Pb and As.

Analysis of air pollution caused by particle matter emission from the copper smelter complex Bor (Serbia)

The main aim of this paper is to present analyses of temporal variations of particulate matter in Bor (Serbia) influenced by copper production at the Copper Smelter Complex Bor. Particulate emissions are of concern because the presence of fine particles (PM2.5 - particles with diametar less than 2.5 ?m) and ultrafine particles (PM0.1 - particles with diametar less than 0.1 ?m) assume higher risk for human health. Such particles can penetrate deeper into respiratory organs and, at the same time, a probability for such penetration and deposition in the respiratory system is greater. The analysis is based on comparison of SO2 and PM measurements at several locations in the area of Bor town in the close vicinity of Copper Smelter. PM concentrations were highly correlated with sulfur dioxide and inversely correlated with local wind speed during pollution episodes. Presented results indicate that the dominant source of coarse and fine particles in Bor town is the Copper Smelting Complex Bor. The most significant factors for particulate matter distribution are meteorological parameters of wind speed and direction. It was found that exceeding of daily limit values of concentrations of PM10 (50 ?g/m3) usually occurs due to very high concentrations in a period of several hours during the day.

Determination of sulphide concentrates of ore copper by XRPD and chemical analysis

Roasting process of sulphide copper concentrates in fluo-solid reactor is an oxidation process, and presents the first stage of copper concentrate processing in Copper Mining and Smelting Complex Bor, RTB Bor. Therefore, the importance of accurate and up to date process control is an apparent precondition for the correct treatment in the following stages and also for of high grade cathode copper. As concentrate is fed into the roaster, it is heated by a stream of hot air to about 590?C. The process takes place between solid and gaseous phases without the appearance of a liquid phase. The heat generated by the exothermic oxidation reaction of sulphur from cooper and iron minerals (chalcopyrite and pyrite) is sufficient to carry out the entire process autogenously at temperature from 620 to 670?C. The temperature of sulphur firing which defines the start of roasting depends on physical traits, particle size of sulfides and characteristic product of oxidation. The obtained products of the roasting process are: calcine, ready for smelting in the furnace and gas-rich sulphure dioxide (SO2), well suited for the production of sulfuric acid. The relationship between the quantitative mineral composition of the charge and of the calcine directly points out to the efficiency of the roasting process in fluo-solid reactor. The amount of bornite and magnetite, resulting from the sulfide oxidation is the most important parameter. Hence, quantitative determination of mineral composition is of great interest. In this work, the results of the determination of quantitative mineral composition of the copper sulphide concentrate (charge) and products of their roasting (calcine and overflow) in fluo-solid reactor in the RTB Bor are presented. The aim was to compare the results of the iron, copper, sulfur and oxygen contents determined by two independent techniques, the chemical (HA) and X-ray powder diffraction analysis (XRPD) that is based on the quantitative mineral composition. Differences in the obtained results are evident, but small enough to confirm the reliability of measurement.

Selective removal of heavy metals from metal-bearing wastewater in a cascade line reactor.

This paper is a part of the research work on 'Integrated treatment of industrial wastes towards prevention of regional water resources contamination - INTREAT' the project. It addresses the environmental pollution problems associated with solid and liquid waste/effluents produced by sulfide ore mining and metallurgical activities in the Copper Mining and Smelting Complex Bor (RTB-BOR), Serbia. However, since the minimum solubility for the different metals usually found in the polluted water occurs at different pH values and the hydroxide precipitates are amphoteric in nature, selective removal of mixed metals could be achieved as the multiple stage precipitation. For this reason, acid mine water had to be treated in multiple stages in a continuous precipitation system-cascade line reactor. All experiments were performed using synthetic metal-bearing effluent with chemical a composition similar to the effluent from open pit, Copper Mining and Smelting Complex Bor (RTB-BOR). That effluent is characterized by low pH (1.78) due to the content of sulfuric acid and heavy metals, such as Cu, Fe, Ni, Mn, Zn with concentrations of 76.680, 26.130, 0.113, 11.490, 1.020 mg/dm3, respectively. The cascade line reactor is equipped with the following components: for feeding of effluents, for injection of the precipitation agent, for pH measurements and control, and for removal of the process gases. The precipitation agent was 1M NaOH. In each of the three reactors, a changing of pH and temperature was observed. In order to verify. efficiency of heavy metals removal, chemical analyses of samples taken at different pH was done using AES-ICP. Consumption of NaOH in reactors was 370 cm3, 40 cm3 and 80 cm3, respectively. Total time of the experiment was 4 h including feeding of the first reactor. The time necessary to achieve the defined pH value was 25 min for the first reactor and 13 min for both second and third reactors. Taking into account the complete process in the cascade line reactor, the difference between maximum and minimum temperature was as low as 6 degrees C. The quantity of solid residue in reactors respectively was 0.62 g, 2.05 g and 3.91 g. In the case of copper, minimum achieved concentration was 0.62 mg/dm3 at pH = 10.4. At pH = 4.50 content of iron has rapidly decreased to < 0.1 mg/dm3 and maintained constant at all higher pH values. That means that precipitation has already ended at pH=4.5 and maximum efficiency of iron removal was 99.53%. The concentration of manganese was minimum at pH value of 11.0. Minimum obtained concentration of Zn was 2.18 mg/dm3 at a pH value of 11. If pH value is higher than 11, Zn can be re-dissolved. The maximum efficiency of Ni removal reached 76.30% at a pH value of 10.4. Obtained results show that efficiency of copper, iron and manganese removal is very satisfactory (higher than 90%). The obtained efficiency of Zn and Ni removal is lower (72.30% and 76.31%, respectively). The treated effluent met discharge water standard according to The Council Directive 76/464/EEC on pollution caused by certain dangerous substances into the aquatic environment of the Community. Maximum changing of temperature during the whole process was 6 degrees C. This technology, which was based on inducing chemical precipitation of heavy metals is viable for selective removal of heavy metals from metal-bearing effluents in three reactor systems in a cascade line. The worldwide increasing concern for the environment and guidelines regarding effluent discharge make their treatment necessary for safe discharge in water receivers. In the case where the effluents contain valuable metals, there is also an additional economic interest to recover these metals and to recycle them as secondary raw materials in different production routes.