Abstract: In the disclosed solution sand to be cleaned is thermally cleaned by rotating the sand being cleaned in a large oven (1) by rotating the oven (1). Before cleaning, the sand may be pre-processed by crushing any lumps and cleaning the sand fraction by magnetic separation. Preprocessed sand to be cleaned and heat energy are fed (5) into the rotating oven. The oven (1) is set slightly inclined so that a second end of the oven (1) is lower than a first end. The inclination and rotating speed of the oven (1) as well as the feed amount of sand are adjusted, whereby the advancing speed of the sand may be adjusted, as well as the ratio of the sand being cleaned to the volume of the oven (1) kept as desired. The temperature of the oven (1) is monitored at the coldest area of the oven, which is substantially at the second end of the oven. The temperature of the oven (1) is adjusted by adjusting the amount of heat energy fed in.

Abstract: An apparatus and a method for cleaning sand used at a foundry, wherein sand to be cleaned is screened by a screening apparatus. The screened sand and at least one liquid mixture is fed into an abrasive apparatus. After that, the screened sand is rubbed by the abrasive apparatus. The rubbed sand and at least one liquid mixture is added to a water separation screen for separating a water blend from the rubbed sand. Finally, the separated sand is transferred into an oven and cleaned thermally by rotating the separated sand in the heated oven.