The paper presents results of measuring thermal conductivity and heat capacity of bentonite foundry sand in temperature range ambient –

900 OC. 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 water vaporization strongly influences thermal conductivity of the moulding sand in the first period of the mould heating by

the poured casting.