Types of foundry sand 

Types of foundry sand
According to the different mineral composition, foundry sand is divided into two categories: silica sand and non-siliceous sand:  1, silica sand:  The main mineral composition is SiO2.
①Natural silica sand: used for molding sand and core sand for non-ferrous alloy castings, iron castings and small and medium-sized steel castings. ②Selected natural silica sand: used for all kinds of molding sand and core sand using organic matter as a binder. ③Artificial silica sand: molding sand and core sand used for steel castings. 2, non-siliceous sand : There are many types and different uses:
① Limestone sand: It is made of crushed limestone, and its main mineral composition is CaCO3. It is used for molding sand and core sand for steel castings.
②Zircon sand: The main mineral composition is ZrO2·SiO2, which is used for the core sand or surface sand of large steel castings and alloy steel parts, or use its powder as a coating.
③ Magnesia: The main mineral composition is MgO, which is used for the surface sand and core sand of high manganese steel castings, and its powder can be used as a coating.
④ Chromite sand: The main mineral composition is FeO·Cr2O3, which is used for the surface sand and core sand of large-scale or special steel castings, and its powder can be used as a coating.
⑤ Corundum sand: The main mineral composition is α-Al2O3, which is used as a shell material for investment and ceramic mold casting. ⑥Olivine sand: The main mineral composition is (MgFe)2SiO4, which is used for molding sand and core sand for iron castings, non-ferrous alloy castings and high manganese steel castings