Challenges and Future Prospective of Alternative Materials to Silica Sand for Green Sand Mould Casting: A Review

Near-net shape casting having complex geometry is manufactured through the sand casting process. However, day by day, the availability of natural or synthetic silica sand has been decreasing and increasing the production cost of sand casting components. Therefore, there is a need to look into low-cost and readily available alternative materials to substitute the commercial-grade silica sand for the sand mould casting process. The constituent of silica sand is primarily silica (SiO2), Al2O3, and Fe2O3. The major constituents of industrial wastes such as fly ash, blast furnace slag, ferrochrome slag, stone dust, and red mud have SiO2, Al2O3, and Fe2O3. Therefore, industrial wastes may be used individually or combined with silica sand at a different ratio to substitute the commercial-grade silica sand in green mould castings. Researchers and scientists have evaluated the suitability of industrial wastes and local riverbed sand as an alternative material for green sand mould castings. The present review summarizes the advantages and constraints of using industrial wastes and local riverbed sand as an alternative to green sand mould casting process.