Abstract: A method for reclaiming green sands having a wide range of moisture and temperature conditions involves processing such sands in a single reclaimer unit to produce free flowing reclaimed sand adapted to pass through a 20 mesh screen and having a temperature preferably no greater than about 120.degree. F. The method involves effecting attrition of a batch of molding sand supplied to the reclaimer unit, applying a vacuum exhaust to the unit primarily to remove a calcined clay binder and water vapor therefrom, sensing the means temperature of the sand, and selectively adding moisture or heat to the sand as required to produce reclaimed sand having predetermined moisture and temperature conditions allowing such sand to be immediately screened of extraneous materials and passed to a mulling device or remixer. The rate of addition of moisture, if any, and the flow of exhaust air through the unit are controlled in order to prevent condensation in the exhaust conduit and dust collection devices.

Abstract: A method of regenerating old casting sand consists of the steps of introducing essentially dry, used casting sand into a single container, then simultaneously subjecting the sand to rapid heating and extreme turbulence by directing a gas flame against the sand having a temperature of at least 1400.degree. C. (2550.degree. F.) along a first axis, rotating a crushing tool about a second axis parallel to the first axis and positioned such that the crushing tool does not pass through the gas flame and rotating the container about a third axis, parallel to the first and second axes. In a preferred embodiment, the container is cylindrical in shape and the third axis is inclined from the vertical at an angle of between 10.degree. and 60.degree., thereby creating upper and lower zones. The burner flame preferably is directed to the sand in the lower zone and the crushing tool is positioned to operate in the upper zone.