The paper presents results of measuring heat diffusivity and thermal conductivity coefficients of used green foundry sand in temperature

range ambient – 600 o

C. During the experiments a technical purity Cu plate was cast into the green-sand moulds. Basing on measurements

of the mould temperature field during the solidification of the casting, the temperature relationships of the measured properties were

evaluated. It was confirmed that the obtained relationships are complex and that water vaporization strongly influences thermal

conductivity of the moulding sand in the first period of the mould heating by the poured and solidified casting