Metal smelters use a large amount of sand as part of the metal smelting process. The foundry industries generally recycle and reuse the casting sand used many times in the casting process. When the sand can no longer be reused in the smelter, it is removed from the smelter and is called "smelting waste sand". Like many waste products, smelting sand has beneficial applications for other industries. A mixture of silica sand coated with a thin film of burned carbon and a residual binder with traces of powder is referred to as casting sand. From the literature available above it was found that the replacement of sand by smelting sand by certain initial percentages gives a marginal increase in hardened properties of normal strength concrete. The main components of the smelting sand are high quality silica of uniform size or lake sand obtained by mold casting of ferrous and non-ferrous metals. Initially the sand will be cleaned prior to casting, but after casting it will be rich in ferrous content of about 95% of its own volume.
The main production of foundry sand is by the automotive industry and by casting the parts of the generator. The most popular and efficient process of casting process in the industry is the sand casting system. The type of green sand is the type of common sand used to prepare the moulds for cast iron. The main constituents of the green sand are high quality silica and bentonite clay (approximately 10% as binder), the water presents sea coal (good casting of approximately 2 to 5%). The type and volume Of the materials used for the molds depend on the type of metal that melts in the mold, but usually the green sand containing 90% of the ingredients around it is used on a large scale. The chemically bonded sand casting system is used in addition to the green sand casting system, which involves the application of one or more organic binders in addition to catalysts and different hardening or fixing processes. In order to provide the cavities in the non-ferrous castings molds it is impractical to produce, therefore the above 97% mixture in casting sand is generally used with the chemically bonded system known as "cores". Each year there are between 10 and 15 million tons of foundry waste in the United States, which includes spent casting dust and sand. Usually, 1 ton of sand casting is required to produce 1 ton of steel.