Over 90% of iron alloy castings are made in disposable moulds, i.e. in raw synthetic moulds. Raw mould mixture is applied in all production process types. Mould mixture is composed of sand as the basic component, binding material, water, and additives. Sand particles take up 70 to 95% of the total mould material in the mixture. The most frequently used sands include quartz sand, chromite sand, and olivine sand. Preliminary study of elution of foundry sand and mould mixture in distilled water has been studied through electrical conductivity measurements, complemented by measurements of the leaching concentrations of Cr 3 % , Al 3 % , Si 4 % , Ca 2 % , Mg 2 % , Fe 3 , and the pH value in eluates after the leaching process.