Mining-induced seismicity, particularly high-energy seismic events, is a major factor giving rise to dynamic phenomena within the rock strata. Rockbursts and stress relief events produce the most serious consequences in underground mines, are most difficult to predict and tend to interact with other mining hazards, thus making control measures difficult to implement. In the context of steadily increasing mining depth within copper mines in the Legnica-Głogów Copper Belt Area (Poland) alongside the gradually decreasing effective mining thickness, a study of the causes and specificity of mining-induced seismicity in specific geological and mining settings may improve the effectiveness of the prevention and control measures taken to limit the negative impacts of rockbursts in underground mine workings, thus ensuring safe working conditions for miners. This study investigates the presumed relationship between the mined ore deposit thickness and fundamental parameters of mining-induced seismicity, with the main focus on the actual locations of their epicenters with respect to the working face in commonly used room-and-pillar systems. Data recalled in this study was supplied by the O/ZG Rudna geophysics station. Based on information about the actual ore deposit thickness in particular sections of the mines (Rudna Główna, Rudna Północna, Rudna Zachodnia) and recent reports on seismic activity in this area, three panels were selected for further studies (each in different mine region), where the ore deposit thickness was varied (panel G-7/5 – Rudna Główna, panel XX/1 – Rudna Północna, panel XIX/1 – Rudna Zachodnia). Data from seismic activity reports in those regions was used for energetic and quantitative analysis of seismic events in the context of the epicenter location with respect to the selected mining system components: undisturbed strata, working face and abandoned excavations. In consideration of the available rockburst control methods and preventive measures, all events (above 1 × 103 J) registered in the database were analysed to infer about the global rockburst hazard level in the panel and phenomena induced (provoked) by blasting were considered in order to evaluate the effectiveness of the implemented control measures.
The article discusses the validation process of a certain method of balancing gas contained in the pore space of rocks. The validation was based upon juxtaposition of the examination of rocks’ porosity and the effects of comminution in terms of assessing the possibility of opening the pore space. The tests were carried out for six dolomite samples taken from different areas of the ‘Polkowice-Sieroszowice’ copper mine in Poland. Prior to the grinding process, the rocks’ porosity fell in the range of 0.3-14.8%, while the volume of the open pores was included in the 0.01-0.06 cm3/g range. The grinding process was performed using an original device – the GPR analyzer. The SEM analysis revealed pores of various size and shape on the surface of the rock cores, while at the same time demonstrating lack of pores following the grinding process. The grain size distribution curves were compared with the cumulative pore volume curves of the cores before grinding. In order to confirm the argument put forward in this paper – i.e. that comminution of a rock to grains of a size comparable with the size of the rock’s pores results in the release of gas contained in the pore space – the amount of gas released as a result of the comminution process was studied. The results of gas balancing demonstrated that the pore space of the investigated dolomites was filled with gas in amounts from 3.19 cm3/kg to 45.86 cm3/kg. The obtained results of the rock material comminution to grains comparable – in terms of size – to the size of the pores of investigated rocks, along with asserting the presence of gas in the pore space of the studied dolomites, were regarded as a proof that the method of balancing gas in rocks via rock comminution is correct.
The current rockburst hazard conditions in the copper mines are the consequence of mining-induced seismicity of the rock strata whilst the majority of registered rockbursts have been caused by high-energy seismic events. T he analysis of seismic activity in recent years indicates that the region of the Rudna mine is the region of the highest seismic activity. This paper is an attempt at evaluating the seismicity levels in the Rudna mine in the period from 2006-2015, within the entire mine and in its particular sections. Key parameters of seismic activity include the number of registered seismic events, total energy emission levels, and a unit energy factor. The variability of Gutenberg -Richter (GR) parameters are analyzed and the epicenters’ locations are investigated with respect to the stope position. T he distinction is made between low-energy (103 ≤ As < 105 J) and high-energy (As ≥ 105J) seismic events ahead of the stope, in the opening-up cross-throughs and in the gob areas. It appears that the risk level of a high-energy event occurrence in the R udna mine has not changed in recent years and has remained on a high level whilst the differences in seismic activity, in particular mine sections, are attributed to the varied extraction height and varied thickness of rockburst-prone carbonate layers in the roof of the copper ore deposit. The analysis of the epicenters’ locations with respect to the stope reveals that no matter what the seismic energy levels, the largest number of rockbursts are registered in the opening-up cross-through zone. Low-energy tremors are mostly located in the gob areas, high-energy events occur mostly ahead of the stope. T hus, the evaluation of the seismicity conditions in the Rudna mine seems to positively verify the relationship between the number of registered events and the levels of generated seismic energy, taking the local geological and mining conditions and the specificity of the room and pillar mining method into account.
In the world-class Cu-Ag deposits of the Legnica-Głogów Copper District (LGCD), constant bulk density values are adopted to estimate the ore and metal resources within them based on the results of previous studies of the LGCD deposits carried out at the stage of their exploration and documentation: 2.6 Mg/m3 for the carbonate series, 2.5 Mg/m3 for the shale series, and 2.3 Mg/m3 for the sandstone series. The main purpose of research was to analyze the range of possible differences at local scale of observation between constant values of bulk densities (hereinafter referred to as reference values) assigned during deposit documentation to the main lithological units and bulk densities of these units determined based on the results of experimental sampling of individual lithological units within the exploited copper and silver deposits (Lubin, Polkowice-Sieroszowice and Rudna). In general, when it comes to Cu-Ag LGCD deposits (or their large parts), the relative diversity of estimates of average bulk densities of ores based on the results of experimental sampling (more than 1,600 samples from different individual lithological units were collected at 500 sampling points in mining excavations) and reference values is low (with a median not exceeding 3%). The results of studies indicate, however, that the application of reference bulk densities at the local observation scale may result in significant underestimation (up to nearly 20%) or overestimation (up to 11%) of real bulk densities of the main lithological units. This may have a noticeable impact on the correct estimation of ore and metal resources in small parts of deposits and, as a consequence, hinder the reconciliation of the planned and actual ore mining production.
The work presents experiment results from the area of copper casting technology and chosen examples of alloyed copper. At present, copper casting technology is applied in many branches of industrial manufacturing, especially in the sector of construction, communications, arms and power engineering. Alloyed copper, containing slight additions of different elements and having special physio-chemical properties, is used in a special range of applications. Copper technology and alloyed copper analyses have been presented, these materials being used for cast manufacturing for power engineering. The quality of casts has been assessed, based on their microstructure analysis, chemical content and the cast properties. During the research, special deoxidizing and modifying agents were applied for copper and chosen examples of alloyed copper; also exemplary samples were tested with the help of metallographic analysis, electrical conductivity and gaseous impurities research.
There are presents the internal recycling in anode furnace, in addition to mainly blister copper and converter copper. During the process there arise the two types of semi-finished products intended for further pyro metallurgical processing: anode copper and anode slag. The stream of liquid blister copper enters into the anode furnace treatment, in which the losses are recovered, e.g. copper, resulting from oxidation and reduction of sulfides, oxides and the oxidation of metallic compounds of lead, zinc and iron. In the liquid phase there are still gaseous states, which gives the inverse relationship relating to the solid phase, wherein the gases found an outlet in waste gas or steam. The results of chemical analysis apparently differ from each other, because crystallite placement, the matrix structure and the presence of other phases and earth elements are not compared, which can be regained in the process of electrorefining. One should not interpret negatively smaller proportion of copper in the alloy, since during the later part of the production more elements can be obtained, for example from sludge, such as platinum group metals and lanthanides. According to the research the quality of blister copper, to a large extent, present in the alloy phase to many other elements, which can be recovered.
Concentrations of four trace elements, copper (Cu), zinc (Zn), manganese (Mn) and seleni- um (Se), have thus far proven to be affected by lentiviral infections in people and rhesus monkeys. As small ruminant lentivirus (SRLV) infection is responsible for one of the most important goat diseases, caprine arthritis-encephalitis (CAE), we evaluated serum and liver concentrations of Cu, Zn, Mn, Se in goats severely affected by symptomatic CAE and compared them with litera- ture reference intervals. Serum and liver samples of dairy goats euthanized due to severe clinical form of CAE were collected and screened for the concentration of Cu, Zn, Mn (54 serum sam- ples, 22 liver samples), and Se (36 serum samples, 22 liver samples) using flame atomic absorption spectrometry for Cu, Zn, Mn and graphite furnace atomic absorption spectroscopy for Se. In both serum and liver samples concentration of Zn was the highest, followed by Cu concentration, and then by Mn and Se. There was no relationship between serum and liver concentrations of trace elements. Liver concentrations of all four trace elements and serum Cu concentration fell within literature reference intervals, although liver Se concentration was mainly in the lower marginal range (between 0.4 and 1.0 mg/L). Serum Zn concentration was elevated (>1.2 mg/L) in all goats, serum Mn concentration was elevated (>0.04 mg/L) in 42 (78%) goats and serum Se concentra- tion was elevated (>1.6 mg/L) in 13 (36%) goats. Concluding, severe symptomatic CAE does not appear to be associated with the level of any of the four trace elements.
The extraction of mineral deposits is usually charged with additional taxes or royalty fees that go beyond the general income tax. As a rule, countries prefer stable sources of fiscal revenues based on the volume of raw material extraction, and investors prefer models based on profit tax, i.e. taking operating costs and risks lower than the expected profitability of the project into account. As a rule, too high a burden for the mining sector affects investors’ decisions regarding the introduction of new investments. There are a number of examples where excessive fiscal burdens force investors to move to countries with more favorable tax systems. An analysis of various forms of taxation of mining enterprises around the world has been presented and compared with the system implemented in Poland. Usually, the countries that apply the royalty fee in the mining sector at the same time introduce a number of adaptation mechanisms. This is crucial for new investments due to the fact that they may to some extent compensate for the high costs of transition from the investment to the operational phase. In most cases, several incentive mechanisms are used at the same time, e.g. the accelerated settlement of investment expenditures and the unlimited settlement of losses. The copper and silver mining tax introduced in Poland increased the discounted effective tax rate (ETR) from 38.5% to 89% for the entire investment period, which resulted in a 11-year return on investment, as well as a drop in the internal rate of return (IRR).There are currently no mechanisms in Poland which would balance the burden of this tax for a new investor. In order to balance the extraction tax for certain minerals in terms of the IRR and ETR key indicators, the introduction of several adaptation mechanisms has been proposed. For new investments the most essential mechanism is the preferential settlement of capital expenditures incurred in the pre-production phase of an investment. The others include accelerated amortization, the ability to deduct certain expenses for the exploration phase from the tax base, along with an extended tax loss settlement period, or a mechanism for deducting a certain percentage of investment expenses directly from the tax.
The presented article describes the relationship between lithological and facies development of reservoir rocks in the area of the roof elevation of the Weissliegend sandstones, with a particular emphasis on the influence of elevation on the occurrence of low mineralization zones in the deposit area. To illustrate the variability of the deposit parameters, closely related to the facies and lithological conditions of the host rocks, three-dimensional lithological and geochemical models for two research areas were developed using the geostatistical methods and based on field observations and the sampling of the deposit. The research area includes parts of the Northern Elevation of Rudna and the surrounding depressions within the boundaries of the Sieroszowice and Rudna deposits. Based on cross-sections of the 3D models, a different deposit formation in the roof elevation area of sandstone formations has been characterized; the lithological profile is defined as „atypical” due to the absence of a copper-bearing shale series, the most characteristic layer for copper ore deposits in the Fore -Sudetic monocline. Large variations in the shape of the deposit and the irregular boundaries of both balance mineralization and enclaves of gangue have been confirmed. The presence of large-scale enclaves of igneous rock in the entire profile of the Lower Zechstein rocks (areas without the balance copper mineralization) and small areas of gangue (sandstone) enriched with anhydrite binders adjacent to the parts of balance deposit located in argillaceous sandstone has been revealed. The possibility of the occurrence of gangue, in the area of the roof elevation of the Weissliegend sandstones directly adjacent to the border with calcareous dolomite, and irregular gangue partings in sandstone formations in the balance deposit was indicated. In addition, small areas of strong enrichment in Cu sulphides were observed in the contact zones between sulphate and clay binders in the Weissliegend sandstone series.
In this work, steady flow-field and heat transfer through a copper-water nanofluid around a rotating circular cylinder, dissipating uniform heat flux, with a constant non-dimensional rotation rate varying from 0 to 5 was investigated numerically using a finite-volume method for Reynolds numbers from the range 10–40. Furthermore, the range of nanoparticle volume fractions considered is 0–5%. The variation of the local and the average Nusselt numbers with Reynolds number, volume fractions, and rotation rate are presented for the range of conditions. The average Nusselt number is found to increase with increasing the nanoparticle volume fractions and decrease with increasing value of the rotation rate.
The separation or beneficiation processes are conducted in many devices and concern many various types of minerals and raw materials. The aim of conducting these processes is always to achieve the best possible results allowing as much of the useful component as possible to be obtained by maintaining reasonable costs of the process. Therefore, it is important to have the possibility to monitor the process effects and to have efficient tools to evaluate the course of it. Generally, the ore’s ability to partition into concentrate and tailings is called its efficiency, upgradeability etc. It can be said that there is no unambiguous measure of upgradeability and there are many factors in use which enable to evaluate it qualitatively. Among them are such commonly known parameters as: recovery, losses, yield, upgrading ratio and many others. They are based on three principal parameters that is the average content of the useful component α, the contents of this component in concentrate β and the contents of this component in tailings ϑ. For a given ore (assuming that α = constant), the multi-product separation results can be treated as points of a trajectory located on the surface of factor w in a three dimensional space (β, ϑ, w). The course of the trajectory depends on the ore petrographic and mineralogical properties preparation for the process. For these reasons, searching for optimal (potential) possibilities of the ore is relative, which is presented in the example of Halbich, Fuerstenau and Madej upgrading curves. Such curves are efficient tools to evaluate the course of a separation (beneficiation) process and each of their types allow the effects to be shown in different perspective. Apart from this, they allow also the optimal feed conditions to conduct a certain process with aim of achieving the expected results to be found. Furthermore, the effect of the ore preparation on the flotation results, on the sum of recoveries of the useful component in concentrate and residual recovery in tailings is presented in the paper. The results indicated that any additional contamination of concentrate should be taken into account during the organization of the flotation process. In this way, the results of fractionated flotation have much valuable information to establish the course of the process.
This investigation is concerned with the extraction of nugget copper particles from copper recovery plant slag which recycled of copper scrap. For this purpose, the Falcon concentrator was used because of its enhanced gravity properties. The Falcon concentrator has a fast spinning bowl which creates a centrifugal force to separate fine size minerals on the basis of their density differences. In the tests, the tailings of the copper recovery plant were used and the test sample was divided into two groups and one of them was classified in narrow particle sizes. The operational parameters were determined as particle size, centrifugal force and washing water pressures. The water pressure and centrifugal force have an inversely proportional relationship. Because of this phenomenon, the G/P parameter was created. The test conditions were applied to the whole distribution sample and narrow size distribution samples in the same way. The test results indicate that the average grade was elevated from 1.04% to 6.50% with the recovery of 15.07% and 619% enrichment ratio for narrow sizes, whereas grade was elevated to 4.36% with 13.24% recovery and 415.94% enrichment ratio for the whole distribution. As a result, the recovery and grade values of concentrates are not good enough for gravity concentration process for both samples. However, this process was applied to the double recycled material and the lower recovery, grade values can be tolerated because of concentrate is nugget copper metal. The concentrate can also be washed in cleaning table for increasing the grade value for adding to initial feed of plant. This process can, therefore, supply important earnings not only economically but also environmentally.
Slag refining slag with west materials was analysed used the DTA methods. In the paper a method of determining the reduction capability, with the Carbo-N-Ox method, of slag solutions was used. Some relations between the stimulators in the environment - slag - metal system allow to initiate mass exchange reactions in the process of slag refining.The presented in work course of behaviour permits on choice of basic composition of slaglite, the of necessary components stimulating quantities, as well as on accomplishment of opinion of ability refinement. The worked out programme Slag-Prop, after introduction of data with experiment, it allows on next corrections in composition of proposed mixtures also, should be put on properly elaborated factors of multistage reaction with essential usage of suitable stimulators.
“Wartowice” tailings pond was closed in 1989, resulting in 232,4 ha tailings pile requiring reclamation. The major problem is heavy metals presence and poor nutrient conditions and physicochemical structure of soil which disturbs the plants development. In order to assess the real condition of studied area the complete biological characteristic has been done. The physicochemical conditions were assessed altogether with phytosociological, microbiological and toxicological studies of deposits. We recorded only 27 species of vascular plants belonging to 15 families on the tailings pond of which 5 belong to Rosaceae, 4 to Asteraceae and 3 to Poaceae and Saliceae. Species inhabiting the tailings depended on their dispersal capacity, metal tolerance and rhizome strategy. Microbiological analyses revealed the low number of bacteria and fungi on the tailings pond, apart from the small uplift area where the plants were indentified. Bacteria identified on the tailings pond were classified to 8 genera. The low number of bacteria suggests the lack of nutrients which affects the development of soil microflora. Toxicity tests showed that post-flotation sludge is not toxic to microorganisms because of its high pH. Some plants, such as lucerne could even influence positively the microorganisms development what has been proved in our studies. The tailings toxicity was higher towards producers, where Secale cereale appeared to be the most sensitive species. Amendment with topsoil from adjacent areas can influence positively the phytotoxic properties of tailings and enrich them into native seeds.
This article describes stability issues of main excavations in deep copper mines in Poland, from the perspective of mining work safety. To protect main transportation and ventilation routes, parts of rock are left untaken to form so-called protective pillars. The problem was to determine the size of main excavations protective pillars in deep underground copper mines in which provide stability of main excavations. The results of numerical simulations of the stability of protective pillars under specific geological and mining conditions are presented, covering: underground depth and width of protective pillar, number, size and layout geometry of protected excavations, as well as the impact of parameters of surrounding gob areas. Problem was solved applying numerical simulations based on the finite element method which were performed in a plane state of strain by means of Phase2 v. 8.0 software. The behavior of the rock mass under load was described by an elastic-plastic model. The Mohr-Coulomb criterion was used to assess the stability of the rock mass. The results of numerical modeling have practical applications in the designing of protective pillars primarily in determining their width. These results were used to prepare new guidelines for protective pillars in Polish copper mines in the Legnica-Glogow Copper District.
In 2011, the Miedzi Copper Corporation (MCC) initiated its exploration program involving deep Cu-Ag deposits in the Fore-Sudetic Monocline. A very vast study area was adopted, along with the use of a wide range of research instruments. In the years 2011–2013 the exploration of MCC involved 21 concession areas. The location of concessions for exploration as well as exploration and prospecting was based on the known prognostic and hypothetical areas with confirmed contact of the Rote Fäule facies with the reduced facies, placed in the proximity of the Zechstein elevations. In 2012 and 2013, historical boreholes drilled mainly by the petroleum industry were logged, and in cases where the preservation of rock material allowed, samples were collected for chemical analyses. Moreover, a wide range of specialized examinations was performed, involving organic chemistry, coal macerals, vitrinite reflectance and petrography, with a particular emphasis on the Rock Eval method. The latter allows the presence of the so-called strong Rote Fäule associated with the presence of the richest mineralized horizons to be established. It was equally important for the purpose of exploration to perform the reprocessing of geophysical data using the innovative method of effective reflection coefficients. This allows transforming a conventional seismic image into an impulse form of seismic records, meaning a temporal sequence of coefficients, whose sections can be correlated with the logs of historical boreholes in order to trace the course of lithological series. This method provides a much higher accuracy for determining structural elements crucial for exploration than before, suggesting the presence of various tectonic phenomena important for mineralization. As a result, a more detailed mineralization distribution model was obtained and the so-called sweet spots were pinpointed, becoming an object of further drilling exploration. The number of active concessions was reduced to 6, which resulted largely not just from the absence of ore, but also from economic premises. The drilling program initiated in 2013 and still continued today allowed the discovery and preliminary documentation of three copper and silver deposits in the Fore-Sudetic Monocline. These are the Mozów and Sulmierzyce deposits, where the presence of prospective areas was previously recorded, as well as the Nowa Sól deposit, discovered in the so-called green field, where no ore exploration was previously conducted. At the current stage of identification, each of these deposits contains resources exceeding 5 million tons of equivalent copper, and the performed economic analyses indicate the viability of their extraction using the modern methods of shaft sinking, air conditioning and waste management.
The “Sulmierzyce-Odolanów” study area analyzed in the present paper constitutes an example of the presence of deep Zechstein metallic mineralization in the Fore-Sudetic Monocline. Unlike the shallow deposits which are being mined nowadays, these types of areas were not previously considered in terms of their possible extraction. However, in recent years, due to the development of modern mining technologies, this situation has changed and these areas have become prospective for the future documenting of mineral deposits. The threshold parameters delimiting an ore deposit, recommended for use when preparing geological documentation and not compulsory, have been established by the regulation of the Minister of Environment. In the case of stratabound Zechstein deposits they take the equivalent percentage and productivity of only two metals, i.e. copper, as the main useful component, and silver into account. This leads to the underestimation of the resources of ore which also contains other metals, including zinc and lead, which is particularly disadvantageous in the case of deep deposits, which from an economic standpoint, it is advisable to focus on their richest parts and to document, and in the future to extract all the useful metals. Also, the regulation of the Minister of Environment does not take into account the fluctuations of the market prices of metals over time, the impact of which on the equivalent content and productivity of these elements in the deposit is considerable. This paper presents the authors’ own formulas intended to calculate polymetallic equivalent content and productivity taking the share of four elements in the ore into account: copper, silver, zinc and lead. They also enable determining these values for arbitrarily selected time intervals and tracing their changes over time. Apart from the quality parameters it is also possible to calculate the value of mineral resources in the deposit expressed in American dollars per one square meter of its area for each selected time interval. The calculations used the results of chemical analyses of historical drill cores originating from the studied area. A total of 135 historical holes located within its boundaries were analyzed. Based on the obtained figures, the time-varying resources of the polymetallic equivalent (Cu-Ag-Zn-Pb) were estimated along with their market value expressed in American dollars for each year in the time interval of 2012–2016.
This paper presents a study of control strategies for 5-phase permanent magnet synchronous motors (PMSMs) supplied by a five-leg voltage source inverter. Based on the vectorial decomposition of the multi-phase machine, fictitious machines, magnetically decoupled, allow a more adequate control. In this paper, our study focuses on the vector control of a multi-phase machine using a linear proportional-integral-derivative (PID) current regulator in the cases of sinusoidal and trapezoidal back-electromotive force (EMF) waveforms. In order to determine currents’ references, two strategies are adopted. First one aims to minimize copper losses under constant torque, while the second one targets to increase torque for a given copper losses. These techniques are tested under a variable speed control strategy based on a proportional-integral (PI) regulator and experimentally validated.
In the last 20 years, a new meshless computational method has been developed that is called peridynamics. The method is based on the parallelized code. The subject of the study is the deformation of open-cell copper foams under dynamic compression. The computational model of virtual cellular material is considered. The skeleton structure of such a virtual cellular material can be rescaled according to requirements. The material of the skeleton is assumed as the oxygen free high conductivity (OFHC) copper. The OFHC copper powder can be applied in additive manufacturing to produce the open-cell multifunctional structures, e.g., crush resistant heat exchangers, heat capacitors, etc. In considered peridynamic computations the foam skeleton is described with the use of an elastic-plastic model with isotropic hardening. The dynamic process of compression and crushing with different impact velocities is simulated.
Eutectic copper oxides (Cu2O) crystallize during the copper solidification process in the ETP grade copper which leads to high oxygen concentrations in interdendritic spaces. It has been experimentally found that they can be regular or elongated, and their size reaches several micrometres. During the multi-cage hot rolling process, homogenization of the oxide distribution in the entire volume of the wire rod occurs. This process is carried out in the soft copper matrix. Throughout the drawing process the fragmentation of oxides transpires along with changes in the shape from angular to more oval in a degree depending on the size of the deformation (wire diameter). Microcracks, fissures and local stress fields in the reinforced copper matrix arise around the oxide particles. The article presents the results of research on the evolution of copper oxides in ingots, wire rods and wires. The results of investigations of the wires properties and the limitations of the drawing process, especially of microwires, are presented.
The aim of this study was to verify the hypothesis postulating that the supplementation of turkey diets with Cu nanoparticles can lower dietary inclusion levels of Cu without compromising the growth rate and antioxidant status of turkeys. The experiment was carried out on 648 one-day-old Hybrid Converter turkeys divided into 6 groups with 6 replicates per group, in a two-factorial design with 3 dietary inclusion levels of Cu (20, 10 and 2 mg/kg) and 2 dietary sources of Cu - copper sulfate (Cu-SUL) and Cu nanoparticles (Cu-NP). At 42 days of age, blood samples were collected from 2 birds per replicate (12 birds per group), after slaughter livers were collected for analyses. Blood and liver samples were assayed for: Cu, Zn, Ca, P, Mg, GLU, TP, ALB, UREA, TAG, TC, UA, ALT, AST, ALT, GGT, ALP, SOD, GPx, CAT, VIT C, FRAP, GSH+GSSG, LOOH, MDA. The results of this experiment demonstrate that a decrease in the dietary inclusion levels of Cu from 10 mg/kg to 2 mg/kg does not compromise the growth performance of turkeys, but weakens antioxidant defense mechanisms. A Cu dose of 20 mg/kg induces oxidation reactions and has a much more inhibitory effect on the antioxidant defense system than dietary Cu content of 2 mg/kg. In turkeys, dietary supplementation with Cu-NP has a more beneficial effect on carbohydrate metabolism and antioxidant status compared with Cu-SUL. The results of analyses examining the antioxidant and metabolic status of young turkeys indicate that 10 mg/kg is the optimal dietary inclusion level of Cu.
In the paper an analysis of the influence of two parameters on the die wear, i.e. the shape of the die and the backpull with the specified force values has been presented. The conical and curve-profile tools have been selected to determine an influence of the die geometry on its wear, and the backpull force has been tested with the use of conical dies. The research was conducted for the drawing of copper wire by sintered carbide die with a mesh diameter of 3 mm. A fixed draw value of 30% relative gap loss was assumed. The axisymmetric numerical model of the drawing process was built and modeled in the MARC/Mentat commercial program for nonlinear and contact issues. As a result of the tests, wear of the dies according to their shape was determined. In addition, for the conical die the drawing force and the force of the metal pressure on the die using different values of the force of the contraction were calculated, as well as wear of the conical die according to the value of the applied backpull force. It has been shown that in the case of the arc die, the distribution of pressure and stress is more uniform over the entire length of the contact zone compared to the conical die. The highest stress gradients occurred in the area of the transition of the crushing part into the drawing part of the die, which caused that the use of the conical die in this area was more than twice as large as the arc die. In addition, on the example of a conical die, it was shown to what extent the depth of its wear decreases with an increase of the test pull force in the range (0-400) of Newtons.
Copper slag is a by-product obtained during smelting and refining of copper. Copper smelting slag typically contains about 1 wt.% copper and 40 wt.% iron depending upon the initial ore quality and the furnace type. Main components of copper slag are iron oxide and silica. These exist in copper slag mainly in the form of fayalite (2FeO ·SiO2). This study was intended to recover pig iron from the copper smelting slag by reduction smelting method. At the reaction temperature of below 1400°С the whole copper smelting slag was not smelted, and some agglomerated, showing a mass in a sponge form. The recovery behavior of pig iron from copper smelting slag increases with increasing smelting temperature and duration. The recovery rate of pig iron varied greatly depending on the reaction temperature.