Reclamation and Application of Composite Chromite Sand
- The source of the rejected chromite sand included two aspects：
- （ 1 ）The rejected sand produced from the unqualified sand cores;
- （2）The mixing-prepared core sand rejected due to having been held too long. The main procedures of the regeneration treatment of the rejected sand were as follows：roasting the rejected sand to make the sand collapse,washing off resin~clay and impurities,and dehydrating the sand by baking,et al.
- Comparison was conducted between using normal raw sand to make cores and using regenerated sand to make cores,the result showed：
- （ 1 ）The usage of regenerated sand could reduce production cost,improve utilization of the resource and reduce pollution;
- （2）The strength property of the regenerated composite chromite sand was good to meet the properties requirements of core sand;
- （3）Inner cavity of castings produced with regenerated composite chromite sand had good smoothness,no burning-on,and thereby could guarantee the inner cavity quality of castings;
- （4）Since regenerated composite chromite sand was used for castings production, the scrap rate caused by core breaking and sand inclusion has been slightly decreased.