Abstract: The waste sands are passed to a calcining chamber having a floor, connecting sidewalls and a top. The floor of the calcining chambers provided with a plurality of vents. The calcining chambers also connected to a separate firebox which produces fluidizing hot gases for fluidizing waste sands within the calcining chamber and forming a fluidized sand bed. The fluidizing hot gases are introduced into the calcining chamber by means of the floor vents. By precisely controlling the temperature of the waste sands within the fluidized bed, a more consistent product is produced while maintaining the temperature of the waste sands below a critical temperature at which the organic binders present on the sand grains would be fused to the waste sand grains.

Abstract: A method is shown for removing minute traces of thermally fused foundry bonding clays from foundry sands reclaimed by a thermal sand reclaimer. The sand grains are passed to a dual fluid bed sand cooler-scrubber having sparge tubes for fluidizing air distribution, finned water cooling tubes and baffle plates for directing sand travel across the tube banks. The fluidized bed extends under a series of dry scrubber cells where the sand grains are hurled through blast tubes toward target plates by blast nozzles. Air current created within the interior of the device creates a controlled negative atmosphere which carries off unwanted traces of oxides and clays, as well as unwanted fine sand grains. The sand grains which are suitable for reuse are captured and deflected into a discharge section of the fluid bed where they flow over a weir by gravity and are discharged for re-use.

Abstract: Hazardous substances are separated from used foundry sand by means of a triple fluid bed thermal reactor, second stage sand cooler and third stage pneumatic attrition scrubber. Temperatures in each of the reactor's beds are precisely controlled, depending upon the nature of the sand being treated, so that hazardous substances can be separated and disposed of, rather than fixing the substances onto the sand grains in insoluble form.