Thermophysical aspects of reclaimed moulding sand addition to the epoxy-SO2 coremaking system studied by Fourier thermal analysis

摘要

The most important advantage of foundry purpose moulding sand is that it can be reclaimed and reused through the casting manufacturing process. Supplying the foundry with a new source of material, sand reclamation brings along both environmental and economic advantages. Utilization of used sand can be considered as a common technological routine in the production of most types of chemically bound moulding materials. The epoxy-SO2 process is prevalent in the processing of cast iron engine components worldwide. Based on its excellent properties, it is mainly suitable for producing internal sand cores with complex geometry. Even though reclaimed sand addition is an active and well-functioning feature in ferrous foundries, the scientific and thermophysical background of its effects on the casting process is yet to be explored. In this work, the thermal aspects of different reclaimed sand levels in the epoxy-SO2 moulding system were examined. Thermogravimetry and differential thermal analysis of the epoxy-SO2 and reclaimed sand in focus were carried out to obtain basic understandings about their high-temperature behaviour. A state-of-the-art Fourier thermal analysis method presented in a recent paper was used at temperatures corresponding to actual cast iron production (1300 ± 10 °C), contrary to the previous tests at the typical temperature range of aluminium melt processing (660 ± 10 °C). By the right of the method, the effects of reclaimed sand addition on the heat absorption (cooling) capacity of the epoxy-SO2 moulding mixtures were investigated.