| Recycled foundry sand can be defined as a | | | | Both these types of sand are suitable for |
| resultant product of the of the ferrous and | | | | recycling and beneficial reuse, however they have |
| nonferrous metal casting industry, where sand has | | | | different physical and environmental properties. |
| been used for centuries as a molding material | | | | Uses of Recycled Foundry Sand |
| because of its superior thermal conductivity. In | | | | Sand from ferrous and aluminum foundries |
| present day foundries, sand is generally recycled | | | | comprise more than 90 % of available sand and is |
| and reused through different production cycles. | | | | usually best suitable for recycling. Ferrous and |
| According to industry experts, approximately 100 | | | | aluminum foundries are generally big in size in |
| million tons of sand is used in production every | | | | comparison to other nonferrous foundries and |
| year. Out of this 100 million tons of sand, 6 to 10 | | | | because of the nature of their production, they |
| million tons is discarded every year that cane be | | | | have more uniform sand streams. This type of |
| recycled into other products and industries. | | | | sand has a history of uses in different types of |
| Sand used at foundries is of superior quality, as | | | | construction applications. |
| companies adopt stringent physical and chemical | | | | Some innovative foundries are finding ways to |
| tests to ensure production of defect free | | | | recycle their used sand. Some other type of |
| castings. Foundries make considerable investments | | | | non-ferrous [ sand, or mixed sand streams can |
| for the quality control of their sand systems with | | | | be recycled if they fulfill the environmental testing |
| rigorous testing done to ensure consistency. | | | | requirements of the regulatory agencies and the |
| Though there are several methods of casting, | | | | required performance standards of the industry. |
| including - die casting, investment casting, and | | | | As with other materials, transportation costs are |
| permanent mold casting, sand casting is by far | | | | usually the highest cost factor in the recycling of |
| the most preferred casting technique. There are 2 | | | | foundry sand. Considering the cost factor, the |
| different methods of using sand in metal casting | | | | best option for the recycling of foundry sand will |
| industry - | | | | typically match the volume and characteristics of |
| - As a molding material that forms the external | | | | the foundry sand with businesses and construction |
| shape of the cast component | | | | projects in nearby areas. |
| - As a core that forms the internal void spaces in | | | | Given below are some of the markets that have |
| products such as engine blocks. | | | | the potential to absorb recycled foundry sand |
| As sand grains do not naturally adhere to each | | | | from different types of foundries - |
| other, binders are used to cause the sand to stick | | | | - Construction Projects |
| together and retain its shape during the | | | | - Cement Kiln Feedstock |
| introduction of the molten metal into the mold and | | | | - Flowable Fill |
| the cooling of casting. | | | | - Manufactured Soils |
| Types of Foundry Sand Suitable for Recycling | | | | In some other cases, foundry sand can be used |
| Generally two types of binders are used in metal | | | | to replace a part of the fine aggregate in several |
| casting industry - | | | | other types of applications, most of which exist |
| - Clay bonded systems (green sand) | | | | at a commercial scale in different markets and |
| - Chemically bonded systems (resin sands) | | | | countries. |