In magnetic separators the phenomenon of magnetic flocculation is an inseparable feature of enrichment of strongly magnetic ores. Non-magnetic particles are bound in the floe internal structure by means of magnetic, surface and mechanical forces which leads to the deterioration of enrichment results. The intensity of flocculation depends on magnetic field intensity, content of the magnetic component in the feed and ore feed rate. The above mentioned factors affect the enrichment results. The paper presents the separation analysis in the band magnetic separator with respect to the magnetic field distribution in the separator working space as well as internal and external mechanical forces, acting on the particle. The author determined the effect of the magnetic compound content in the feed and the amount of washing water on the recovery of this component in the concentrate as well as the effect of the magnetic component content in the feed and the magnetic force density on the residue of the non-magnetic component in the concentrate. The analysis was performed according to the physical model of magnetic separation, presented in the paper. The theoretical dependences, derived from this model, are in good agreement with the results of empirical research, found in the literature.

The equilibrium EMF's were measured for the Al-Ti solid alloys in the region of o:(Ti) phase by means of the concentration cells. Experiments were conducted at the temperatures 923 K, I O 14 K, 1041 K and 1061 Kand in the concentration range from XA1 = 0.0222 to 0.1237. Next, the temperature-concentration dependence of excess Gibbs energy of Al was worked out (Red I ichKi ster relation) and used to calculate the partial and integral thermodynamic functions (excess Gibbs energy, enthalpy of solutions, excess entropy and activity of aluminium and titanium, integral enthalpy of mixing and excess entropy).

The objective of this paper is to identify non-metallic inclusions occurring in aluminium-killed steel with regulated sulphur content and modified with calcium, explain the reaction between calcium and non-metallic inclusions and identify secondary metallurgy parameters, which condition obtaining such forms of inclusions to be favourable to improvement in steel machinability. Computer-aided thermodynamic calculations and production experiments were carried out. They enabled to determine technological parameters of treatment in liquid steel ladle deoxidised with silicon and aluminium, with low (0.01%) and increased (up to 0.03%) sulphur content. By comparison of the computer-aided simulations and production experiment results it was found that calcium in the steel both modifies the aluminium oxide inclusions and reacts with sulphur, whereas deep desulphurisation (below O.Ol%) is favourable to oxide modification. Non-metallic inclusions of calcium aluminates, which affect positively the rnachinability of steel, appear in liquid state in the steel bath. During conventional casting and cooling down large ingots of steel with increased sulphur content, aluminates are significantly depleted in calcium as a result of reaction between calcium and sulphur dissolved in these aluminates and steel matrix. To obtain aluminates and (Ca,Mn)S sulphides rich in calcium in finished products accelerated steel cooling is to be applied, which takes place during continuous steel casting. In steels modified with calcium, there is higher homogeneity of distribution and sizes of inclusions on finished products' cross-section and higher globularisation of these inclusions in comparison to non-modified steels. Improved steel machining properties in these steels and improved isotropy of mechanical properties in bars made from it were found.

In lost foam process, application of protective refractory ceramic coatings on patterns made from foamed polystyrene plays a very important part and decides about the quality of produced castings. The coating should be made from a material of suitable strength and good permeability to give free way of escape to gaseous products which are formed due to the thermal destruction of a pattern. In this work an attempt has been made to determine the criteria for technological estimation of these coatings. A device cooperating with the apparatus for determination of the moulding sand permeability was designed and manufactured. To enable a comparison of the strength of various tested coatings, the relevant equations have been derived. In the present investigation several types of ceramic coatings were applied and their composition was based on the following materials: quartz flour, zircon flour, mullite, hydrolysed ethyl silicate - 40, copolymer silicate binder, sizol 0-30. The thickness of the examined coatings was 1.0±0.1 mm and 1.5±0.1 mm for single-layer and double-layer coatings, respectively.

The mathematical description of the hydrogen desorption process from liquid aluminium and its alloys in the bubbling process was presented. The mathematical model based on the equation for the mass transfer coefficient and dimensionless number of the hydrogen concentration introduced by Sigworth and Engh is presented. This mathematical modelling was carried out for the continuous reactor under the atmospheric pressure. Also, the selection of main thermodynamic and kinetic parameters, that are essential to modelling calculations, was done. Among the most important parameters there are: the hydrogen solubility in aluminium and its alloys, the interfacial contact area in the system: liquid metals - the bubble of refining gas (this area can be determined using estimated values of the bubble rise velocity and the bubble diameter), and the mass transfer coefficient. The hydrogen solubility in aluminium alloys can be described basing on the activity coefficient calculated from Wagner's interaction parameters. This model and correctness of assumptions, which were made, were verified. The comparison of the calculated hydrogen concentration with the industrial data for AK-64 alloy refining in a continuous reactor under the atmospheric pressure was carried out. The simulation of the refining process under vacuum based on the experimental data for AK-64 alloy under atmospheric pressure was done.

Comparison of the processes of spontaneous dissolution of brasses and CuCd alloy under hydrogen depolarization was made. Observations of specimens surface using a scanning microscope during the reaction were carried out. An identification of phases of solid products of the dissolution by means ofX-rays diffraction analysis was performed. Among the solid products of the dissolution a separate phase of copper hydride was found. The lattice parameters of copper hydride obtained after the dissolution process of brasses and CuCd alloy are identical.

Methods of progressive precipitation strengthening enabling to eliminate the disadvantageous y' phase, formed during the discontinuous transition ,are presented. Elimination of y' precipitates makes the CuNi I OAl3 alloy attain very high mechanical properties. Application of the presented methods of heat treatment gives also the possibility to modify the amount, the size and the morphology of the strengthening precipitates, which enables to control the mechanical properties of the alloy.

The method based on the grazing incident angle geometry was applied for stress measurement In surface layers of polycrystalline samples. The advantage of this geometry is a constant penetration depth of the X-ray beam during experiment, however, the interpretation of experimental data is more difficult than for the standard technique. Diffraction elastic constants have 10 be calculated for various hkl reflections. The influence of elastic anisotropy on the results of stress measurement is studied.

The study of the mechanical properties comprised fracture surface examination, texture and microstructure observations of copper samples, which were cold rolled, beginning from the recrystallized state or initially deformed by Equal-Channel Angular Pressing (ECAP) up to equivalent deformation E= 2.7. In cold rolled recrystallized copper, intensive shear band formation on the sample scale as well as on micro-scale was observed; shear bands in cold rolled copper, initially ECAP processed, were difficult to observe. Higher ultimate strength and greater elongation were measured in tensiled samples, cut out in RD direction of rolled to z= 96% copper sheet and preliminarily ECAP processed samples; strain marks on the lateral surface of such a sample in the neck region demonstrated the grain size diameter lower than I μm. Fracture surface observation of ruptured sheet samples of recrystallized copper has shown that it is possible to explain the lower elongation as a result of localised deformation in shear bands. In both cold rolled sheets, texture with { 112 }<11-1> ideal orientation was observed, although in preliminarily ECAP processed copper the dispersion of crystal orientation around the ideal orientation was smaller.

Accurate prediction of springback is essential for the design of tools used in sheet metal stamping operation. This investigation aims to clarify the process conditions of three different bending operations of aluminium alloy brass and deep drawing quality steel sheets, by performing some experiments and finite-element simulation. The computer code MARC was used to simulate the V-die bending process under plane-strain condition. It provides a model, which predicts the precise final shape of products after unloading, in relation to the tensile properties of the material, especially instantaneous strain hardening parameters.

In the paper the theoretical sintering criterion was applied to check if sintering conditions of bearing aluminium matrix composites manufactured by recycling of communited aluminium and CuA18 aluminium bronze chips, as reinforcing phase, determined experimentally were proper chosen. The criterion bases on the assumption that by conformability of plastic work of composites in metal working processes with critical values of the work needed for good junction of the particles determined in other simple test, the proper conditions of bonding process of particles can be achieved. The composites were manufactured directly, without metallurgical process. The method of recycling contains: cleaning and communition of chips, premolding, hot extrusion and heat treatment during which the diffusion of copper and aluminium between matrix and reinforcing phase takes place and leads to create the hard intermetallic phases in soft matrix, the structure typical for bearing materials.

Solidification modeling based on classical macroscopic energy, mass, momentum and solute continuity equations does not allow lo predict of microstructural parameters satisfactorily. In past decades several aucmps have been made for the developing of modelling methodology for the coupling macro transport equations with the transformation kinetics in the micro scale. The micromodeling focused to the multicomponent alloys is still rare, despite the majority of the new industrial alloys are formed from complex multicomponent systems. The paper presents the micromodeling procedure coupled with thermodynamic calculation and experimental investigations for the Co-Cr-Mo alloys, frequently used as biomaterials for the production of endoprotheses. Both, experimental and numerical results showed that: the grain structure is mainly influenced by the cooling rate, the partition coefficients exhibit significant dependency on the cooling rate (especially for molybdenum), the high cooling rate promotes early formation of fine intragranular carbides. The experimentally obtained values of latent heat of solidification exhibit important dependency on the initial carbon content, and cannot be ignored in solidification simulations. The solidification modeling results have been verified using cooling curve analysis and metallografic investigations. It seems, that the model can be used in engineering applications for solidification simulations.

Aktuell werden Vakuumverfahren bei der Erzeugung von Sauerstoffreien Kupfer eingesetzt, das ais Ausgangsmaterial in der Elektronik und Elektrotechnik dient. In der Kupfervakuumraffination eine grundlegende Bedeutung hat die Entfemung von Blei. Intensitat der Verunreinigungsentfernung erlaubt eine Anwendung von anderen Einsatzmaterialen ais Kathodenkupfer for die Erzeugung von Kupfer hoher Reinheit. Das Kupfervakuurnraffintionsverfahren beruht auf der Verdampfung der fluchtigen Komponente des flussigen Metalls und ist hauptsachlich durch den Massentransport in der Gas-und in der flussigen Phase determiniert. Die Temperatur und die Druckanderungen in dem Messystem sowie die hydrodynamischen Bedingungen konnen bedeutend die kinetische Kontrole des Prozesses beeinflussen. Ausser dem, die chemische Zusamrnensetzung der Legierung, besonders Anwesenheit oberflachenaktiver Substanzen, kann die Kontrole des Verdampfungsprozesses andern. Feststellung, welcher von diesen Faktoren den grossten Einfluss auf die Verdampfungskinetik hat, verlangt eine Bestimmung der Art der Prozesskontrole mit Faktoren die die Kontrole beeinflussen. Alle Voraussetzungen die die kinetische Kontrole des Verdampfungsprozesses betreffen, fordem genaue Untersuchungen.

This paper contains a description of a new method of coke reactivity testing, which makes it possible to evaluate the degree and intensity of degradation of coke grains with various initial sizes. The results of coke reactivity testing with the use of this method are presented including degrees of mass decrement of coke samples with various initial grain sizes, decrement of average-size grain of tested coke during its gasification and mechanical resistance of coke samples after gasification. Based on the test results, the conditions were determined, under which determination with the use of the new method is carried out, as well as coke reactivity evaluation indices were specified. The new testing method has been verified, under Sendzimir Steelworks conditions, as for the possibility of using it to evaluate the impact of coke granularity on the course of the blast-furnace process.

The paper presents a method which allows to eliminate the y' (Cu, Ni),AI phase of discontinuous transition occurring during ageing of CuNilOAI3 alloy. Introduction of additions such as Si or Ti in the amount of some tenths of percent into CuNi I 0Al3 alloy causes that y' phase of the discontinuous transition is not precipitated. CuNilOAI3 alloy, free from the Iamellar y' precipitates, formed in the discontinuous transition, attains very high strength properties and good deformability.

There were investigated some initial structural transformations which take place in ureafurfuryl binding systems. They were investigated by FTIR spectrometry. There were also used two different techniques: transmission and diffuse reflection (DRS). The spectra were recorded within a range of 400-4000 cm'. The subjects of studies were two modified urea-furan resins (Kaltharz F700 and Kaltharz U404U) and the hardening process with two activators. Changes in FTIR spectra during hardening of the resins were recorded after the time of I, 2, 4, 8 and 24 hours. In comparison there were also examined mechanical properties (tensile strength and bending strength) of sands prepared with these resins. Changes in the spectra of both resins with different activators were visible in the same range of 1400-1700 cm" in about 2 hours since the moment of making the sand; then the number of the bands and their intesity were decreasing. From the conducted tensile and bending tests of the sand it follows that the highest increase of these parameters takes place within the time ofup to 2 hours; then the strength increases but only slightly. As it follows from the preliminary studies, FTIR spectroscopy, and DRS technique - in particular, can be helpful in assessment of the hardening degree ofmoulding sands with organic binders and in getting familiar with the mechanism of the hardening process of these binders. There are also needed further investigations, especially to identify all the peaks in obtained spectrums.

The method of the calculation of strain distribution is based on the measurements of the displacements along the length and transverse cross-section of the conical working zone. Two measuring methods have been used. In the "classical" method the typical measuring microscope equipped with goniometric table has been used. The second method based on the photogrammetric analysis of the pictures has been elaborated and proved by authors. The special computer program has been elaborated for the photograrnmetric image analysis and the later final results receiving. This method can be recommended as the best for using in the practice of researches carried out at the real object. The experiments carried out during the rolling of condenser tubes using pilgering process show that the each transverse section of input tube is twisted during successive working cycles.

The article shows the results of simulation studies conducted on metal matrix composites applying the method of the dynamics of molecular particles. The described method has been illustrated with numerical examples of the simulation and verified by experiments. The numerical computations have been made on supercomputers available at the Academic Computer Centre in Kraków, while experimental studies were conducted by the Foundry Research Institute in Kraków.

Investigation of the converter slag reduction process in electric arc furnace have been carried out for several years. The aim of the investigations is to obtain the non-metallic phase in the form of the Portland clinker. In the investigations presented, the conditions are determined under which obtaining the non-metallic phase as the Portland clinker is possible.

Clasical thermodynamic analysis of any thermal and chemical process is usually based on the first law of thermodynamics. Such an approach is not sufficient when deeper understanding of the mechanism and nature of each elementary process is required. The use of the first and second law of thermodynamics together is necessary to solve practical problems more effectivly. Especially, application of the entropy generation rate and lost available energy (or exergy) concepts enhance our understanding of thermal process. Such an extended analysis is proposed to detect possible ways to decrease the electric energy consumption. Additionally, least squares adjustment procedure is proposed to make mathematical models of elementary processes taking place inside electrolysis cell more reliable.

On the basis of the earlier evaluation Bi-Cd system was critically assessed by means of CALPHAD method and using the most current thermochemical data for the constituent elements. The influence of various factors on the quality of data fitting was shown on the example of this systems.

Basing on the literature data concerning the sessile drop topic, a method of surface tension of liquid metals and alloys measurements using numerical methods has been developed. The computational procedure used in the experiment was the least square estimation of the parameters of the differential equation describing the shape of a sessile drop of liquid. After a series of tests which confirmed the correctness of the employed computational procedure, the method was used in the surface tension measurements of liquid copper.

Basing on a stress relaxation t<:_st, the activation volume V* of Zn (99.995%) monocrystals deformed in the system (OOO I)< 1120> at the temperatures 77 K and 293 K was determined. The density of forest dislocation on the plane (0001) was 104 cm". The investigations have shown that the relaxation process in zinc monocrystals proceeds in two stages. Each stage is characterized by a different value of the activation volume V*. The kinetics of the process depends to a great degree on the temperature of the test and the stresses at the beginning of relaxation.

Transmission Electron Microscopy is an essential technique for imaging the microstructures at the nanometer scale. However, quantitative analysis of such images is not easy due to the nature of TEM contrast based on diffraction phenomena. A quantitative description of the microstructure of melt-spun AIY ribbons has been carried out in the present work. TEM observations have revealed randomly distributed and oriented spherical nanometer crystals. ln order to describe quantitatively their size and shape, images under different diffraction conditions were recorded. These images have been analyzed using software for image analysis. The data have been compared to the results obtained by other techniques, such as X-ray diffractometry and differential scanning calorimetry.