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2596541 
Journal Article 
Green sand reclamation using a fluidized bed with an attrition nozzle 
Cruz, N; Briens, C; Berruti, F 
2009 
1 
Resources, Conservation and Recycling
ISSN: 0921-3449 
54 
1 
45-52 
WOS:000271433700006 
The objective of this study was to determine the technical feasibility of green sand reclamation using attrition in a gas-solid fluidized bed. Reclamation of foundry sand is becoming important as it may help solve concerns related to transportation and dumping of the used sand, and reduce production costs by recycling sand. The crucial step in green sand reclamation is the removal of small clay particles that are bound to the sand particles.



For this study two different types of green sand were used and supplied by two different foundries. Tests were performed in a fluidized bed equipped with an attrition nozzle operating at pressures either 350 or 550 kPa (50 or 80 psig). Attrition experiments for one green sand were performed on either unburned or burned (calcined) green sand, to determine the effect of prior calcination of the green sand on its reclamation potential by attrition. Calcination temperatures of over 700 degrees C were employed, and the results suggest that calcination facilitates the removal of clay from the green sand.



Green sand was analyzed for clay and organic content, acid request, and particle size before and after attrition. Attriting calcined green sand produces the best results. Also experiments conducted at the highest attrition pressure of 550 kPa gave good results. According to the mass balance, the mass lost during the attrition process may be limited to less than 14%, and this could be considered acceptable. The volume of air required for the attrition nozzle is rather high and this may adversely affect the economics of the process. (C) 2009 Published by Elsevier B.V. 
Green sand; Foundry sand; Recycling; Attrition; Grinding; Reclamation