RTB Bor Research Articles

Dynamic Modelling, Experimental Identification and Computer Simulations of Non-Stationary Vibration in High-Speed Elevators

Modelling the dynamic behaviour of elevators with high lifting velocities (contemporary elevators in building construction and mine elevators) is a complex task and an important step in the design process and creating conditions for safe and reliable exploitation of these machines. Due to high heights and lifting velocities, the standard procedures for dynamic exploitation are not adequate. The study presents the method of forming a dynamic model to analyse nonstationary vibrations of a rope with time-varying length with nonholonomic boundary conditions in the position where the rope is connected with the cabin (cage) and in the upcoming point of its winding onto the pulley (drum). A unique method was applied to identify the basic parameters of the dynamic model (stiffness and damping) based on experimental measures for a concrete elevator. Due to the verification of this procedure, the experiment was conducted on a mine elevator in RTB Bor, Serbia. Using the obtained computer-experimental results, the simulations of the dynamic behaviour of an empty and loaded cage were shown. In addition, the study shows the specific method as the basis for forming a control program that would enable the decrease in vertical vibrations during an elevator starting and braking mode.

Analiza dinamičkih parametara liftova sa rešenjem zbirne akvizicije podataka tokom eksperimentalnih istraživanja

Modelling of the dynamic behaviour of elevators with high lifting velocities (contemporary elevators in building construction and mine elevators) is a complex task and an important step in the design process and creating conditions for safe and reliable exploitation of these machines. Due to high heights and lifting velocities, the standard procedures for dynamic exploitation are not adequate. With the purpose of identifying the basic parameters of the dynamic model (stiffness and damping), a unique method was applied, based on experimental measures for a concrete elevator. Due to the verification of this procedure, the experiment was conducted on a mine elevator in RTB Bor, Serbia. Simulations of the dynamic behaviour of an empty and loaded cage are presented using the obtained computational-experimental results

Kisele rudničke vode iz rudnika bakra u jugoistočnoj Srbiji - lokalni problem sa uticajem na međunarodnom nivou

Through this study special attention was paid to AMDs, originating from copper mines, containing different heavy metal ions, and a certain amount of sulphuric acid. The research was conducted on the territory encompassing the RTB Bor mines (now Serbia Zijin Bor Copper). The AMDs occurrences, their water composition, metal potential, and impact on the local surface waters were determined. The major amount of mine waters flow into the Krivelj River damaging extremely its water quality. The research also included monitoring the Timok river water quality along its course from the Krivelj River inflow to the confluence with the Danube. Evaluating the metal losses, it was found that every year around 360 tons of copper, >500 tons of iron, and 30 tons of zinc from mine waters are lost, as being transported via the Krivelj River to the Timok and then to the Danube.

Contribution to the Examination of the Mechanisms of Copper Loss with the Slag in the Process of Sulfide Concentrates Smelting

This paper presents the results of an experimental investigation into the distribution of copper in the slag of an industrial reverberatory furnace sulfide concentrates smelting process in the copper smelter RTB Bor (Serbia). The influence of copper content in the matte, the temperature and the height of the slag on the content of copper in the slag was determined as Cuoxide, Cusulfide and Cutotal and was based on possible mechanisms for the loss of copper in a silicate slag from the smelting of sulfide copper concentrates. The greatest quantity of copper in the silicate slag was found in the form of matte particles, which were captured in the slag as a result of the “flotation” of SO2 gas which was formed by magnetite reduction with FeS at the slag–matte interphase boundary.

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 possibility of the application of copper slag in asphalt mixtures

Rapid industrial development over the last decades has led to the creation of a diversified industrial waste that poses serious environmental problems. On several occasions attempts have been made to increase the reuse of waste and alternative materials for the construction of civil engineering structures. One of these materials is the copper slag that is byproduct of melting and processing of copper ore. The objective of this paper is to investigate the possibility of using copper slag from RTB Bor in asphalt mixtures for wearing courses of pavement structures. For this purpose, the testing of two asphalt mixtures AB11s with different percentages of the content of copper slag, as a partial replacement of the natural aggregate, was carried out. The replacement percentage of copper slag was 25% and 50% of fractions 2/4, 4/8 and 8/11.2 mm. The obtained results were compared with the control mixture. In addition to the physico - mechanical characteristics of the slag (density, water absorption, toughness and abrasion characteristics, affinity between slag and bitumen, particle shape), the subject of this research is the design of asphalt mixtures according to the Marshall method and testing of the water resistance, stiffness and resistance to permanent deformation of asphalt mixtures with slag. The results of these tests show that asphalt mixtures with cooper slag have better water resistance, but lower resistance to permanent deformation, lower stiffness at low frequencies (high temperatures) and higher stiffness at high temperatures (low frequencies).

MINING-METALLURGICAL SOURCES OF POLLUTION IN EASTERN SERBIA AND ENVIRONMENTAL CONSCIOUSNESS

The ethics of environmental protection is based on the moral responsibility of a man not to endanger his living environment because it is the only way for creating the conditions for a better life quality. Environmental consciousness (EC) is characterized by a high awareness about the environment, especially in urban areas with mining-metallurgical sources of pollution. Raising EC in such environments causes acceptance and ecological and social responsibility. A mining-metallurgical complex plant represents an important source of pollution of urban areas. In that sense, Bor is an interesting urban area having in mind that it represents one of the most important ore and metal production centers in South-East Europe. What defines the EC of Bor inhabitants is derived from the very town and its economy. The research encompasses concrete environmental problems of the mining town Bor and its surroundings. The components of the EC of people living in Bor were analyzed according to the awareness, knowledge and attitude method, having in mind the extent to which the environment has been polluted in this area. It has been concluded that the perception of people living in Bor about the state of the environment depends on numerous factors – first, whether the employee works for the RTB Bor Company or not.

Evaluation of the sustainable development benefits in the Serbian mining companies

Sustainable development is the most current topic of today; it means a moderate development that meets the needs of the present generation, and does not interdict the needs of future generations. An analysis of the sustainable development benefits in the mining companies (Mining and Smelting Basin Bor, RTB) presents a problem that can be solved using the multi-criteria decision-making methods (MCDM). The interest in analyzing the benefits of sustainable development in the Mining and Smelter Basin Bor originated from the fact that the benefits influence the growth, development and survival of the company. One approach based on the AHP method is proposed to solve the complex problem in this paper. The usability and effectiveness of the AHP approach has been considered in the empirical application of the proposed method for assessment the sustainable development benefits in the mining companies of Serbia (RTB Bor).

The effect of smelting and granulation on some properties of smelter slag

The technogenic copper deposit of slag Depo 1 is located in the industrial district of the Smelter and Refineries of RTB Bor. Exploitation reserves are 9 190 940 t of slag with the average copper content of 0.715%. Sample of this deposit was melted in a furnace and then cooled with a jet of water when it was poured into a thin jet, whereby the small - granulated pieces were formed. Comparison of some properties of this sample was done with the sample in the form in which it was deposited in the deposit. This paper presents the chemical analysis, SEM - EDS analysis, Bond working index in a rod and ball mill, grinding kinetics and experiments of flotation concentration of copper depending on the grinding fineness in the range of 60 - 95% - 0.075 mm.

Reprocessing of the old flotation tailings deposited on the RTB Bor tailings pond - a case study

Flotation waste, which was produced through seventy years of copper ore processing in RTB Bor, Serbia, is deposited in a flotation tailings pond. In total, almost 26.4 Mt could be considered as available for eventual reprocessing and reuse. Chemical analysis has shown that an average concentration of targeted metals in the tailings is: 0.183% Cu, 0.35 g/t Au and 2.17 g/t Ag. The tailings contain 60 to 70% of SiO2, 10 to 17% of Al2O3 and pyrite 5 to 8%. Flotation tailings reprocessing consisted of acid leaching followed by re-flotation of the leach residue. Leaching of the tailings resulted in leach liquors containing Cu2+ ions from 50 to 580 ppm. The average copper removal degree in the leaching stage was 70%. After re-flotation, the total copper removal degree reached 83 to 85%. Sulphur removal degree reached 77%. Sulphur concentration in the treated tailings was reduced almost 5 times compared to the inlet concentration. An equivalent amount of iron was also reduced through the flotation process. Concentration of total copper was reduced 3 times.

Treatment of Wastewater from New Copper Smelter RTB Bor

RTB Bor smelter and sulfuric acid plant modernization project includes reconstruction of an old wastewater treatment plant (WWTP). The task for a team from the Innovation Center of TMF was technical-technological solution for the reconstruction of WWTP with a new wastewater treatment process. Wastewater from the primary copper smelter is very acidic, with a high content of dissolved heavy metals and arsenic. Treatment of wastewater includes the neutralization of the acid, precipitation of the heavy metals in the form of hydroxides by using hydrated lime, and the arsenic co-precipitation with iron(III) hydroxide. Material and energy balances of the process are determined by simulating the wastewater treatment in Superpro Designer software package with thermodynamic parameters defined in HSC Chemistry program. The simulation results were confirmed by experimental tests at the pilot plant level. The designed process is applied in WWTP exploitation within the new copper smelter RTB Bor. Treatment of 8,7 m2/h of wastewater generates 7,2 m2/h of treated wastewater and 10,3 t/h of wastewater treatment (WWT) sludge. The WWT sludge is characterized as hazardous waste requiring treatment prior to disposal. A proposed treatment for WWT sludge is solidification/stabilization (S/S) using a mixture of fly ash and hydrated lime. Results of laboratory scale tests, which included standard leaching tests EN 12457 and TCLP, as well as the compressive strength testing of obtained solidificates, shows that the S/S treatment leads to stabilization of more than 99% of the heavy metals and more than 90% of arsenic. The treated sludge has the characteristics of non-hazardous waste and is suitable for disposal.

Thermal shock properties of glass-ceramics synthesized from a glass frit

In this study, the behavior of glass-ceramics synthesized from a glass frit of FFW (Final Flotation Waste) originated from the RTB Bor Company was investigated. Thermal shock resistance was monitored in order to assess the possibility of application of such waste material. Thermal shock of the samples was conducted using water quench test. Image analysis and ultrasonic measurements were used as nondestructive methods for quantification of thermal shock damage at the surface and in the bulk of the specimens. Phase composition of samples was determined by X-ray powder diffraction (XRPD). The degradation level of samples was about 43 % after 20 cycles of water quench tests. The results pointed out that glass-ceramic material exhibited good thermal shock resistance.

Application of the final flotation waste for obtaining the glass-ceramic materials

This work describes the investigation of the final flotation waste (FFW), originating from the RTB Bor Company (Serbia), as the main component for the production of glass-ceramic materials. The glass-ceramics was synthesized by the sintering of FFW, mixtures of FFW with basalt (10%, 20%, and 40%), and mixtures of FFW with tuff (20% and 40%). The sintering was conducted at the different temperatures and with the different time duration in order to find the optimal composition and conditions for crystallization. The increase of temperature, from 1100 to 1480?C, and sintering time, from 4 to 6h resulted in a higher content of hematite crystal in the obtained glass-ceramic (up to 44%). The glass-ceramics sintered from pure FFW (1080?C/36h) has good mechanical properties, such as high propagation speed (4500 m/s) and hardness (10800 MPa), as well as very good thermal stability. The glass-ceramics obtained from mixtures shows weaker mechanical properties compared to that obtained from pure FFW. The mixtures of FFW with tuff have a significantly lower bulk density compared to other obtained glass-ceramics. Our results indicate that FFW can be applied as a basis for obtaining the construction materials.

Multicriteria ranking of workplaces regarding working conditions in a mining company

Ranking of workplaces with respect to working conditions is very significant for each company. It indicates the positions where employees are most exposed to adverse effects resulting from the working environment, which endangers their health. This article presents the results obtained for 12 different production workplaces in the copper mining and smelting complex RTB Bor – ‘Veliki Krivelj’ open pit, based on six parameters measured regularly which defined the following working environment conditions: air temperature, light, noise, dustiness, chemical hazards and vibrations. The ranking of workplaces has been performed by PROMETHEE/GAIA. Additional optimization of workplaces is done by PROMETHEE V with the given limits related to maximum permitted values for working environment parameters. The obtained results indicate that the most difficult workplace is on the excavation location (excavator operator). This method can be successfully used for solving similar kinds of problems, in order to improve working conditions.

Characteristics of Wastewater Streams Within the Bor Copper Mine and Their Influence on Pollution of the Timok River, Serbia

Wastewaters produced by mining and metallurgical treatment of polymetallic sulfide ores have polluted the Timok River in Serbia for more than 100 years. We have characterized seven different wastewater streams within the RTB Bor facilities, investigating their influence on pollution of the Timok River before its confluence with the Danube River. Their relative contribution was calculated by considering the contaminant load of each wastewater stream and non-conservative transport along their flow paths. Three sampling spots in the Timok River, before and after its confluence with the Borska River, were also monitored.

Environmental impact of mining activity in Bor area as indicated by the distribution of heavy metals and bacterial population dynamics in sediment

The environmental impact of inorganic pollution is pronounced in water adjacent to Bor Copper Smelter Complex (RTB Bor, Serbia), with Cu, Zn, Pb, and As being the main determinants of aquatic pollution pattern. Communities of microorganisms present in the sediments are mainly affected by heavy metal pollution. Some groups of bacteria can be considered pollution bio-indicators, due to their sensibility and ability to bioaccumulate heavy metals, thus contributing to reducing pollution. This study investigates the relationships between trace element accumulation and heterogeneity in sediment bacteria community structure found in water streams adjacent to the Bor Copper Smelter Complex (RTB Bor, Serbia). Our results showed no contamination with copper, zinc, nickel, iron, and chromium, but did show a low to moderate contamination with lead and a moderate to high contamination with arsenic in aquatic sediments within the area of interest. Spatial heterogeneity in sediment-associated bacterial communities did not relate significantly to location of sampling sites, except for iron reducing bacteria. Iron reducing bacteria and nitrifying bacteria were the best distinguishing groups of bacteria. However, only iron reducing bacteria were significantly influenced by sampling locations. The iron reducing bacteria has correlated negatively with the degree of sediment contamination with lead, and therefore, we suggest that this group of bacteria could serve as potential bio-indicators of inorganic water contamination in Bor RTB area.

Possibility for application of GIS technologies in RTB Bor group

Possibility for application of GIS technologies in RTB Bor group

Characterization of soil in the coastal area of the Bor River abstract

Production process of copper obtaining in the Mining and Smelting Company (RTB) Bor directly affects the environmental pollution in Bor and surrounding area. Harmful elements present in the air are deposited on the surface and due to the effects of atmospheric precipitation penetrate into deeper layers of soil. On the other hand, in the area of RTB Bor activity, the significant pollution of rivers and soil are present in coastal area due to the increased concentrations of present heavy metals. The Bor River is particularly endangered where the waste industrial and mining waste water flew for many years. The Bor River has become on time one of the most polluted rivers in Europe. This paper presents the results of physico-chemical characterization of soil samples from the coastal areas of the Bor River. The following parameters were analyzed: moisture content, pH value, bulk density, specific gravity, grain size distribution, chemical composition, toxic characteristics-TCLP Method and leaching test - Method for characterization of waste leaching. The obtained results indicate that the soil is contaminated with heavy metals and that a significant deviation from the permissible concentrations was found in particular for the following elements: Cu, As, and Pb. The soil in the coastal area of the Bor River belongs to the category of hazardous waste and the preventive measures are necessary in accordance with defined regulations.

Conversion of flotation processing using the heap leaching method in the mine Cementacija - Kraku Bugaresku in the Copper mine Bor

RTB Bor is planning to expand the capacity of mining and processing at the Cementacija Kraku Bugaresku site from the current 2.5 million tons per year to 5.5 million. The current processing technology - the classic flotation of the entire excavated ore, without the separation of oxide and sulfide ores, due to the low copper recovery from oxide ore, has achieved the modest financial results. This article discusses an alternative method of copper obtaining using the hydrometallurgical heap leaching and SX / EW extraction method from leach solutions, in terms of economics, i.e. comparative analysis of cash flow and discounted cash flow for both cases (scenarios). The analysis is performed in a software for strategic planning and design in mining - Whittle Fx , with the input techno-economic data for both cases [7]. Due to the frequent breakdowns and causing the accidental situations on the current infrastructure installations of the processing plants, pipeline for pulp-hydro transport from the site to the flotation plant, in conclusion, to emphasize the comparative advantages of hydrometallurgical processing are emphasized in the conclusion not only in terms of the economy but also the environmental protection. In the world, the world's largest copper producers have a tendency to make, besides copper is necessary and valuable metal, also the 'green' metal.

Mineralogical characteristics of slag (from the Flotation plant of RTB Bor) granulated in the laboratory conditions

A sample of slag from the Flotation Bor, RTB Bor, was mineralogical tested after granulation in the laboratory conditions. Minerals contained in the sample of granulated slag are: fayalite and ferrite that form the basis with rarely sprayed fine particles of magnetite, pyrite, chalcopyrite, bornite, copper matte and elemental - native copper [6, 7]. Granulation of slag was conducted in the laboratory conditions on the device specially designed for this purpose.