Sand Reclamation

                Means the fully recovery of the sand grade for use as a direct substitute for new sand. Aims at removing all undesirable objects from the used sand and restores the sand to as nearly to its original conditions as possible.

Advantages:

1)      Offers the economical utilization of the sand which would otherwise need to be dumped out to make space for new sand.

2)      Offers an approach to complete self sufficiently of the system.

3)      Properly reclaimed sand functions like new sand.

4)      Eliminates necessity of storing new sand in bulk and thus reduces inventory size.

5)      Reclaimed sand will automatically fulfill all the requirements of new sands.

Sand reclamation techniques:

a)      Dry reclamation:

In dry reclamation process, fines, spent and free clay, fractured sand grains and iron oxide particles etc. are removed from the used sand.

b)     Wet reclamation:

1)      Removes fines and foreign matters from the sand.

2)      Removes partly clay coating from the sand grains.

3)      Does not remove completely, carbonaceous and organic materials from the sand grains.

4)      Like dry reclaiming, does not convert the used sand into an original one.

c)      Thermal reclamation:

1)      Involves heating the sand to 1200 – 1500f.

2)      Carbonaceous and organic materials get burnt and are removed.

3)      Does not remove clay content.

4)      Very suitable for oil bonded sand which contains no clay.

5)      Preferred for non-ferrous foundries performing all core molding.

6)      Very effective in reclaiming shell mold sand.

7)      Is not recommended for foundries using clay binders.

d)     Combined wet plus thermal reclamation:

1)      Restores the quality of the original sand. The sand reclaims its original shapes, size and distribution.

2)      Remains fines, clay, organic and carbonaceous materials.

3)      Thus reclaimed sand produces casting as good as those made by original sand.