SAND

This residue comes from the molds used by foundries to cast their products. Originally, the sand is composed of 99.9% pure silica. The foundries subsequently add certain products as bentonite, coal dust (which explains the black color) and other additives according to their particular requirements. After being used in the foundry process, the sand still contains approximately 90% silica.

Treatment

The treatment consists of passing the sand through a sieve. A magnetic pulley on the conveyor belt removes the metal fragments. The other debris such as wood, plastic,
fabric, etc. is removed by hand. A drum
crusher breaks down the larger sand
pieces until the grains of sand are reduced
to the required size. The resulting product
is then stored in pile before being delivered
to the user.

Sand sample