Evaluating the Appropriateness of Selected Foundry Sands for the Casting of Reactor Housings: A Study Based on Physicochemical Characterization Outcomes

In the case of desulfurization and spheroization of cast iron using the in-mold method, in which the treated cast iron is poured into the reaction chamber and placed in the casting mold, the mineral raw material of the mold should support these processes. Therefore, it is important to know the physicochemical properties of the materials selected for the production of casting molds and to learn about the phenomena occurring during their pouring. The research presented in this paper was carried out on quartz, magnesite, chromite, and olivine sands. The results not only provide a comprehensive understanding of these materials but also have significant implications for reactor housing casting. Two of the three tested quartz sands meet all the standards, allowing quartz raw materials to be foundry sands. Marked by the authors of this work, P11 sand, which is classified as 1K grade by the seller, does not meet the requirements of the Polish standard PN-85/H-11001 for this grade and should be classified as 2K grade. At the same time, attention was drawn to relatively considerable weight losses at 1350 °C for the tested quartz raw materials. More significant losses on ignition were found for magnesite sand than the value permitted by the Polish standard, which should be associated with the fact that derivatographic tests were carried out in an oxidizing atmosphere. In the analysis made for olivine sand, the obtained data indicated that the magnesium content is slightly below the requirements of the relevant standard; on the contrary, the iron content exceeds the standard requirements. Analytical data obtained for chromite sand indicated that it meets the PN-91/H-11007 standard regarding chemical composition, but X-ray diffraction tests showed that the tested sample is not chromite but magnesiochromite. The results of grain size distribution, chemical composition, X-ray diffraction, SEM/EDS, and TG/TG presented in this paper show that before starting the production of a specific molding mixture, each time most of the parameters characterizing sand used should be controlled because the properties may differ from the manufacturer's declaration.