The aim of this study was to evaluate foundry waste used for various applications in terms of heavy metals quantity of fractions of their binding. The novelty of these studies is the use of speciation procedures to assess the fraction of heavy metals in foundry waste. The two most popular speciation procedures, the Tessier method and the SM&T, and also the TCLP single extraction procedure were used to evaluate the use of foundry waste in agritechnique, road engineering and construction in this research. Additionally, local soils were analyzed and compared to landfill foundry waste (LFW). It was found that LFW may have a negative impact on the natural environment when used for agrotechnological applications due to the increased concentration of mobile and bioavailable fractions (mean 9–18%) of metals. Foundry dusts were characterized by a low percentage of mobile and bioavailable (mean 2–6%) forms, although this does not include electric arc fournance dust (EAFD) (mean 17%). The metal content in TCLP extracts was low in all foundry waste samples and allowed the use of the analyzed wastes in construction and road construction. The usefulness of both speciation procedures for the assessment of the leaching of heavy metal forms from foundry waste was confirmed. However, the SM&T procedure was more effective in leaching mobile and bioavailable forms of heavy metals in foundry waste and soil samples.

This paper discusses the agrotechnical use of foundry waste based on spent foundry sands (SFS). The advantage of foundry waste use is its high concentration of quartz sands and its similar physical properties to soils, including good permeability and filtration rate. An important component of foundry waste containing a mineral binders (green sands) is the presence of a clay fraction. In contrast, organic binders in some foundry wastes increase the percentage of organic matter. However, organic binders may contain toxic substances that are hazardous to the biota. Therefore, it is not recommended to use foundry waste with organic binders in agriculture or horticulture. Moreover, heavy metals may be problematic in the agrotechnical use of foundry waste mainly derived from cast metal. The disadvantage of using foundry waste as soil substrates is the low proportion of fertilizing components. Due to the low content of nutrients in foundry waste, it is recommended that it is used as a structural component mixed with other additives, such as sewage sludge or compost. The paper presents the results of research on the content of pollutants and the assessment of the biotoxicity of foundry waste. Based on the analyzed literature reports and own research, it was found that the use of foundry waste for non-industrial purposes, such as the production of artificial horticultural substrates, soilless substrates and artificial soils (Technosols), should be preceded by numerous studies to confirm the absence of negative impacts on the environment and human health.