Reclaiming Sand is a Process, and a Goal

New sand reclamation technologies have become fairly trendy in recent months as foundries look for ways to maximize raw material investments and minimize the costs involved in meeting the disposal requirements for spent sand. But that does not make foundry sand reclamation a new development—or that foundries have not been reclaiming spent sand for a long time, and in high volumes.

Waupaca Foundry is proof of that. The Wisconsin-based operator of four foundries that pour 9,500 tons of gray, ductile, compacted graphite, and austempered ductile iron daily is also an exemplary reclaimer of mold and core sand. By adopting advanced sand reclamation at two locations, Waupaca has significantly minimized the environmental impact at those foundries and achieved cost control by reusing the recovered resources.

The technique in use by Waupaca is a three-stage process involving two Simpson Technologies pneumatic scrubbing systems as the first and third step, with a thermal process step in between.

The reclamation process

Waupaca’s sand reclamation system begins with dry, returned green sand being processed through the first Simpson Pro-Claim unit, using pneumatic technology. The Pro-Claim machine operates continuously, requiring no operator and minimal maintenance. The machine has no moving parts that come into contact with sand. This initial step aids in removing any chemical binders, residual dry raw materials, and debris.

In the second step, the sand is subjected to high heat in the thermal unit that burns off any remaining organic material.

Finally, the sand passes through a second Pro-Claim system to aid in removing any residual dust fines and perform final cleaning, helping to establish an optimal grain size and quality for moldmaking and coremaking processes.

According to Waupaca, this process allows its metalcasting operations to reuse sand more than 30 times before it reaches the end of its lifecycle. And by decreasing its new sand requirements, reducing landfill waste, and promoting beneficial reuse, it supports the foundry’s sustainability goals.

Sustainability in action

By implementing sand reclamation, the Waupaca Foundry has reduced its reliance on raw sand resources, which are often locally mined, and decreases the volume of waste sent to landfills. Having sand available on location also reduces transportation costs and emissions associated with sourcing and disposing of materials.

This approach parallels a broader trend in manufacturing toward circular resource management. By keeping sand in the production cycle for as long as possible, Waupaca Foundry maximizes material efficiency and minimizes environmental impact.

In addition, Waupaca’s reclamation process delivers tangible cost control and operational benefits. Reusing sand multiple times reduces the need for new sand purchases, consequently cutting procurement and transportation costs.

Additionally, because the Simpson Pro-Claim machines are low-maintenance units with minimal oversight requirements, and coordinate well with the foundry’s established workflows, they have provided a good return on investment.

Simpson Technologies has supplied high-quality and customized systems and service to Waupaca Foundry for several decades. The Pro-Claim units’ reliable performance and Simpson’s partnership and technical support have been instrumental in Waupaca’s sustainability efforts. By reducing waste, conserving resources, and promoting efficiency, the foundry is an example of sustainable metalcasting.