Q. Describe Natural and Synthetic Sand?

Natural sand: A natural sand is the on which is available from natural deposits. Only assistive and water need to be added to it to make it satisfactory for moulding. The clay content of most natural sands is slightly higher than the desired so that new sand can be continuously added to the used sand to replenish that which is lost.

Synthetic sand: A synthetic sand is prepared by mixing a relatively clay free and having a specified type of clay binder as well as water and other additives. All are mixed in the foundry. This sand has the advantage that sand grains of specified composition and properties can be prepared on the basis of the metal being cast.