The scope of work included the launch of the process of refining slag suspension in a gas oven using a variety of technological additives.
After the refining process (in the context of copper recovery), an assessment of the effect of selected reagents at the level of the slag
refining suspension (in terms of copper recovery). Method sieve separated from the slag waste fraction of metallic, iron - silicate and
powdery waste. Comparison of these photographs macroscopic allowed us to evaluate the most advantageous method of separating
metallic fraction from the slag. After applying the sample A (with KF2 + NaCl) we note that in some parts of the slag are still large
amounts of metallic fraction. The fraction of slag in a large majority of the elements has the same size of 1 mm, and a larger portion of the
slag, the size of which is from 2 to 6 mm. Definitely the best way is to remove the copper by means of the component B (with NaCl ) and
D (with KF2
). However, as a result of removing the copper by means of component C (with CaO) were also obtained a relatively large
number of tiny droplets of copper, which was problematic during segregation. In both cases we were able to separate the two fractions in a
fast and simple manner.
The suspension of the copper droplets in the post-processing slag taken directly from the KGHM-Polska Miedź S.A. Factory (from the
direct-to-blister technology as performed in the flash furnace) was subjected to the special treatment with the use of the one of the typical
industrial reagent and with the complex reagent newly patented by the authors. This treatment was performed in the BOLMET S.A.
Company in the semi-industrial conditions. The result of the CaCO3, and Na2CO3 chemicals influence on the coagulation and subsequent
sedimentation of copper droplets on the crucible bottom were subjected to comparison with the sedimentation forced by the mentioned
complex reagent. The industrial chemicals promoted the agglomeration of copper droplets but the coagulation was arrested / blocked by
the formation of the lead envelope. Therefore, buoyancy force forced the motion of the partially coagulated copper droplets towards the
liquid slag surface rather than sedimentation on the crucible bottom. On the other hand, the complex reagent was able to influence the
mechanical equilibrium between copper droplets and some particles of the liquid slag as well as improve the slag viscosity. Finally, the
copper droplets coagulated successfully and generally, were subjected to a settlement on the crucible bottom as desired / requested.
The article presents the results of research aimed at increase of the efficiency of gas cleaning equipment based on the Venturi tube using high-intensity ultrasound. The model based on known laws of hydrodynamics of multiphase mediums of dust-extraction in Venturi scrubbers was proposed. Modification of this model taking into account ultrasonic field allows evaluating optimum modes (sound pressure level) and conditions (direction of ultrasonic field, square and number of ultrasonic sources) of ultrasonic influence. It is evaluated that optimum for efficient gas cleaning is the mode of ultrasonic action at the frequency of 22 kHz with sound pressure level of 145. . . 155 dB at the installation of two radiators with area of 0.14 m2, four radiators with area of 0.11 m2 or six radiators with area of 0.08 m2 at the angle of 45 degrees to the axis of Venturi tube. Numerical calculations showed that realization of ultrasonic action is the most efficient for the reduction (up to 15 times) of the content of fine-dispersed fraction (2 μm and less), which is impossible to extract without ultrasonic action. The received theoretical results were confirmed by industrial testing by typical dust-extraction plant and used as foundations of development of apparatuses with the radiators of various sizes.
This investigation was undertaken to determine the optimum conditions for physical-chemical treatment of waste water contaminated with heavy metals in the industry of metallic coatings. The industry uses substances such as: inorganic acids, alkalis, acidic and alkaline metal salts, that has a high water demand in the processes of flushing and cleaning the parts to be coated. According to the preliminary characterization of samples and reported in the literature theory, physico-chemical process was implemented for the removal of contaminants that consisted in chemical oxidation of CN-ions, followed by chemical precipitation made next to a coagulation/flocculation and subsequent adsorption on activated coal. Laboratory scale tests showed the optimal conditions of treatment including chemical oxidation by the addition of 4.15 cm3 of H2O2(30%) per gram of CN, chemical precipitation with NaOH to a pH of 12, followed by coagulation/flocculation with Fe2(SO4)3 at a speed of 135 rpm for 3 min and 20 rpm for 20 min and finally the addition of 1.0 g of adsorbent previously activated at 700°C. From this study, it is clear that the adsorption on activated carbon is highly efficient in the removal ofheavy metals from industrial waste water from electroplating. However, it is also clear that the parallel application of the treatments, shown here, is more effective to completely remove contaminants such as lead, nickel, silver, and copper at la-boratory scale, so it is recommended the simultaneous use of these physico-chemical processes.
The removal of nitrates from aqueous solutions is cumbersome because of their high solubility in water. The use of zero-valent iron (ZVI) for the reduction of nitrates is the chemical process and it is an alternative method to the biological ones. The aim of the present study was to evaluate the eff ectiveness of nitrates removal from water solution by using the ZVI process. The process was coupled with the removal of COD, phosphates and turbidity by using by-products of nitrates reduction. Batch tests were performed to evaluate the eff ectiveness of ZVI in the removal of nitrates from aqueous solutions. The eff ectiveness of nitrates removal was analyzed after 5, 10, 20, 30 and 60 min. and compared to the initial concentration of pollutants. Simultaneously analysis of ammonium nitrogen and nitrites was controlled to identify products of nitrates reduction under various pH. The removal of COD, phosphates and turbidity was also performed in batch tests. The eff ectiveness of the emoval by using three types of chemicals was compared – PIX, FeSO4, and waste Fe2+/Fe3+ from the ZVI process. The results obtained in the study indicate that ZVI can be eff ectively used in the treatment of water polluted with nitrates and the by-products of the process could be further applied in the removal of COD, phosphates and turbidity. Based on the results the method should be advised as a promising alternative to the technologies used nowadays under technical scale as a technology that fits with a circular economy.
In this article a three-dimensional mathematical model of radiofrequency ablation during open-heart surgery is presented. It was developed to study temperature field distribution into myocardial tissue. This model uses an anatomically correct 3D model for the left atrium, obtained by magnetic resonance imaging (MRI) processing of a patient; takes into account thermoelectric characteristic differences depending on the area of electric current application; considers cooling by the air flow. An ex-vivo experiment on the pig’s heart was performed where the depth of myocardium tissue damage was measured for the model validation. It was shown that the deviation of the model data from the experiment is within the limits of instrumental measurement error. The developed model is proposed to be used for heart ablation procedures planning, or new equipment development.
The purpose of the presented research is to analyse possible methods of thickening of the Microcystis aeruginosa (Kützing) Kützing cyanobacteria using the obtained concentrate as a biomass for the production of energy carriers and bio-logically valuable substances. Method of cyanobacteria thickening under the action of electric current and in the electric field, as well as the method of coagulation–flocculation and gravity thickening, was experimentally investigated in lab-scale conditions. Electrical methods didn't show positive results for the Microcystis aeruginosa thickening, despite the re-ports of their potential efficiency in a number of previous studies. The high efficiency of the method of coagulation–flocculation and gravity thickening of Microcystis aeruginosa suspensions was obtained. The optimum concentrations of industrial polymeric coagulants and flocculants for the thickening of Microcystis aeruginosa suspensions were defined in the range of about 10 ppm for the coagulants and about 1 ppm for the flocculants. Negative effect of the previous cavitational treatment of the diluted suspensions of Microcystis aeruginosa on the effectiveness of the coagulation–flocculation and gravitational thickening was confirmed experimentally. Hydrodynamic cavitation should be recommended to use after the thickening as the next step of processing of concentrated suspensions of Microcystis aeruginosa to achieve maximum extraction of energy carriers and biologically valuable substances.
The suspension of copper droplets in the slag is considered. The copper/slug suspension is delivered as the product from the direct-toblister
process which is applied in the KGHM – Polska Miedź (Polish Copper) S.A. factory. The droplets / slag suspension was treated by
a special set of reagents (patented by the authors) to improve the coagulation process. On the other hand, the observations are made to
estimate if the melting / reduction process in the furnace is sufficiently effective to avoid a remaining of carbon in the copper droplets.
The coagulation process was carried out in the crucible (laboratory scale). However, conditions imposed to the coagulation / solidification
process in the laboratory scale were to some extent similar to those applied usually in the industry when the suspension is subjected to the
analogous treatment in the electric arc-furnace. Some suggestions are formulated how to improve the industrial direct-to-blister process.
Coagulation and solidification of the copper droplets suspend in the liquid slag are usually accompanied by the appearance of the Cu-Cu2O eutectic. Locally, this eutectic is created in the stationary state. Therefore, frequently it has a directional morphology. Since the E = (Zn) + Zn16Ti – eutectic is similar in the asymmetry of the phase diagram to the Cu-Cu2O – eutectic, the (Zn) single crystal strengthened by the E = (Zn) + Zn16Ti precipitate is subjected to directional growth by the Bridgman’s system and current analysis. Experimentally, the strengthening layers (stripes) are generated periodically in the (Zn) – single crystal as a result of the cyclical course of precipitation which accompanies the directional solidification. These layers evince diversified eutectic morphologies like irregular rods, regular lamellae, and regular rods. The L – shape rods of the Zn16Ti – intermetallic compound appear within the first range of the growth rates when the irregular eutectic structure is formed. Next, the branched rods transform into regular rods and subsequently the regular rods into regular lamellae transitions can be recorded. The regular lamellae exist only within a certain range of growth rates. Finally, the regular rods re-appear at some elevated growth rates. The entropy production per unit time and unit volume is calculated for the regular eutectic growth. It will allow to formulate the entropy production per unit time for both eutectic structure: rod-like and lamellar one.
Ultrasonic processing in the cavitation mode is used to produce the composite materials based on the metal matrix and reinforcing particles of micro- and nano-sizes. In such a case, the deagglomeration of aggregates and the uniform distribution of particles are the expected effects. Although the particles can not only fragment in the acoustic field, they also can coagulate, coarsen and precipitate. In this paper, a theoretical study of processes of deagglomeration and coagulation of particles in the liquid metal under ultrasonic treatment is made. The influence of various parameters of ultrasound and dispersion medium on the dynamics of particles in the acoustic field is considered on the basis of the proposed mathematical model. The criterion of leading process (coagulation or deagglomeration) has been proposed. The calculated results are compared with the experimental ones known from the scientific literature.