Foundry sand is used to create castings of all shapes and sizes. Once spent, this foundry sand needs to be disposed of or reused if possible. The metal casting process generates an estimated 6-10 million tons of spent foundry sand every year. By reclaiming the spent sand, it can either be reused in future metal casting operations or incorporated as a component of other materials, such as concrete, rather than being landfilled. Reusing foundry sand can reduce waste, reduce landfill usage, and cut costs for foundries. It isn’t too difficult or costly to implement.
Benefits of Recycling Foundry Sand
Like other forms of recycling, recycling foundry sand is good for the environment and promotes a circular economy. When properly recycled, spent foundry sand saves energy and reduces water consumption.
Recycling sand also reduces the need to produce new foundry sand, conserving natural resources. This is especially important because producing new foundry sand is becoming increasingly complex.
Additionally, foundry sand is expensive for foundries to procure and discard. Buying virgin sand is costly, and recycled sand can have similar, sometimes better, properties compared to virgin sand, such as fewer impurities and more consistent particle sizes.
What can Recycled Foundry Sand be Used For?
Foundry sand can be recycled and reused after the castings have been made. During the shakeout process, sand molds are separated from castings. The excess sand removed by shakeout equipment is transported back to the sand storage area for evaluation and potential recycling and reuse in future molds. Some shakeout equipment can make sand recovery easier. For example, the VIBRA-DRUM® is a shakeout and sand/casting conditioner all in one, designed to make sand reclamation easier.
Sand that is too burnt or overused to be used in future molds can be sent off-site for disposal, recycling, or repurposed for other applications.
When sent to an off-site recycling facility, foundry sand can be used in the following applications:
- As an ingredient in concrete, bricks, sub-base, and asphalt
- Construction fill
- Compost (Depending on the amount of trace metals in the sand)
- Mine reclamation
- Manufactured soil (Depending on the amount of trace metals in the sand)
All of these materials need to be cleaned appropriately, either on-site or off-site, before they can be reused. Generally, the sand is run through a screen and a magnet to remove any trace metals, ensuring it is clean enough to be recycled.
Challenges
Recycling sand isn’t without challenges. Depending on individual state regulations, you may not be able to recycle all of your sand off-site and may have to dispose of it. Be aware of your local laws and ensure the sand you’re disposing of is compliant with them, so it doesn’t harm the local environment. Cleaning the sand and having it lab-tested for metals and silica is a good way to ensure compliance with regulatory standards.
Additionally, if you plan to reuse the sand for future molds, resource management and waste management must be monitored to prevent it from negatively impacting new molds used with on-site refurbished sand.
Recycle Foundry Sand with GK
Recycling foundry sand presents an invaluable opportunity for foundries to embrace sustainable practices while simultaneously reducing costs and conserving natural resources. By reclaiming and repurposing spent sand, the metal casting industry can significantly lessen its environmental footprint and contribute to a circular economy. If your foundry is looking to enhance its recycling efforts and learn more about efficient processes for handling foundry sand, contact General Kinematics today. Our expertise can help you implement practical solutions that help reduce costs and promote a more efficient sand reclamation operation.
