Regeneration of resin bonded moulding materials
Moulding material regeneration is the recovery of sands from cold resin bonded used moulding material in the operational circulation process. The proportion of reclaimed sand can be far in excess of 90%. The used moulding material, called used sand, passes through the processing steps of mechanically breaking the resin sheath (binding agent residues) through crushing or striking, grinding or sanding, followed by sifting and screening to separate unwanted undersized and oversize fractions and dust. Separating particles according to different density through fluidisation in the fluid bed is possible as well. In combined systems (fluid bed coolersifter), the used sand is also cooled. When chrome ore sand is used in addition, it can be separated with a magnetic separator. The reclaimed sand is conveyed into the respective used sand bunkers (silos), where it is available again for the production of a mixture in the flow-through mixer with a proportion of new sand.