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.

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.

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.