Reclamation – advantage to use!
When applying a new binder system, our customers are interested in its effects to their reclaimed sands, if inserted after the casting process completely or partially into their system.
We tested this effect in cooperation with the foundry institute of the TU Bergakademie Freiberg in a large number of test series. For this purpose, used sand of our new binder system PUROLiT was gradually added to a new-sand system: the maximum addition of used core sand was 25%.
The following sand characteristics were measured in the accompanying molding material test: strength, gas emission and permeability, active clay content and loss on ignition. The graph shows examples of the test results for wet tensile and green compression strength. In the case of clay-bonded H32 quartz sand, the wet tensile strength with PUROLiT bonded core sand up to 25%, measures typical values between 0.25 and 0.3 N/cm². The green compression strength is also in the ideal range with constantly 18 N/cm².
A compatibility with new sand is thus guaranteed.
impact of used PUROLiT-sand to new sand
reclamation of used PUROLiT-sands
Used PUROLiT-sand can be treated easily by mechanical and/or thermal reclamation. After this process it can again be used as molding material. In experiments at TU Bergakademie Freiberg even higher strengths than with new sand were achieved using mechanically regenerated used sands with the same amount of binder.
The bending strengths of PUROLiT bonded H32 new sand and mechanical regenerated sand are shown below.