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The paper presents the results of basic research on the influence of the properties of sand grains on electrical properties of water glass moulding sands. It shows electrical properties of the main component – sand grains, crucial to the kinetics of moulding sands heating, such as permittivity εr and loss factor tgδ. Measurements were carried out with the use of the perturbation method for silica, chromite and olivine sands of different mineral, chemical composition and particle size distribution, as well as for moulding sands with water glass grade 145. Analysis of the results of measurements of electrical properties shows that all moulding sands are characterized by a similar permittivity εr and loss factor tgδ. It was found that the electrical properties and the quantity and quality of other components may have a decisive influence on the effectiveness and efficiency of the microwave heating of moulding sands with sand grains. In determining the ability to efficiently absorb the microwave radiation for mixtures which moulding sands are, the impact of all components influencing their individual technological parameters should be taken into account.

Presented are results of a preliminary research on determining a possibility to use microwave radiation for drying casting protective coatings applied on patterns used in the lost foam technology. Taken were measurements of permittivity ετ and loss factor tgδ at 2.45 GHz, as well as attempts were made of microwave drying of a protective coating based on aluminium silicates, applied on shapes of foamed polystyrene and rigid polymeric foam. Time and results of microwave drying were compared with the results obtained by drying at 50 °C by the traditional method commonly used for removing water from protective coatings. Analysis of the obtained drying kinetics curves demonstrated that selection of proper operation parameters of microwave equipment permits the drying time to be significantly shortened. Depending on kind of the pattern material, drying process of a protective coating runs in a different way, resulting in obtaining different quality of the dried coating.

The paper presents a research on abrasion resistance of selected construction materials designed for foundry tooling applied in the innovative microwave heating process of moulding and core sands. One of the main selection criteria of the materials for foundry tooling, in particular for models, moulding boards, moulding boxes and core boxes, is their good abrasive wear resistance. Usability of the selected polymeric materials, designed for foundry tooling used in electromagnetic field, is decided also by other evaluation criteria determined in the examinations, like thermal resistance and electrical properties. Abrasion resistance of the selected materials was determined for three grades of the moulding sand matrixes. Combined analysis of the determined abrasion resistance, considering also electrical properties and thermal resistance of the foundry tooling materials, characterising their usability for microwave heating of moulding and core sands, will make possible their systemising with respect to effectiveness and efficiency of the heating process, taking under consideration durability of such foundry tooling to be used in industrial conditions.

Presented are results of a research on a possibility to use innovative microwave heating for thermal neutralisation of asbestos-containing wastes. In comparison to traditional heating, the innovative process is characterised by up to a hundred times reduced energy consumption and two hundred times shorter processing time. Parameters of effective disposal, i.e. microwave radiation power and heating time, as well as kind and quantity of the wetting agent necessary in the microwave heating process that intensifies the process and ensures uniform heat distribution in the heated charges, were determined for five most commonly used products containing various fractions of asbestos fibres. It was demonstrated that the presented innovative and eco-minded technology of disposing asbestos-containing materials is a quick, cheap, economical and effective solution guaranteeing complete degradation of the hazardous fibres.