Analysis of effectiveness of used sands reclamation treatment - in various technological devices

The analysis of effectiveness of spent sands reclamation treatment performed in technological devices of various intensity of dry reclamation - during which used binding material is being removed from grain surfaces - is presented in the paper. Variety of reclamation influences was considered via the realization of the so called elementary operations such as: rubbing, grinding and crushing [1-5], which are realised mainly in dry mechanical reclamation devices but also appear in other technological devices for sand preparation. The model rotor reclaimer and two types of mixers used for preparing initial foundry sands with resin U 404 and hardener 100 T3 of the Hüttenes-Albertus Company were applied for tests. The theoretical model for assessing the effectiveness of reclamation treatment developed by the author [3, 4], was experimentally verified [5, 7], with the application of standard testing procedures. The model can be considered a new tool enabling the selection of optimal reclamation times for the given used sand at the assumed intensity of silica sand matrix recovery. Sand mixture of a proper composition fulfilled needed technological properties after total hardening was used as charge material in experiments. The reclamation treatment consisted of mechanical and mechanical-cryogenic reclamation performed within a wide range of times and conditions influencing the treatment intensity.