The following markets have the potential to absorb large volumes of metalcasting sands from different types of facilities:

Construction Projects
Construction applications are by far the most common uses for foundry sand. The greatest volumes of FS are currently used in construction applications such as structural fills, general fills, road and building bases, and embankments. Foundry sands are designed to have high structural integrity in the foundry, where they must hold their shape in contact with metals being poured at up to 3,000 degrees. Green sands have been shown to perform well in structural fills and bases where they typically exhibit higher strengths than native soils.  For more detail about the many uses of FS in the Construction industry, please visit the APPLICATIONS section of the website.

The Federal Highway Administration (FHWA) published the first edition of Foundry Sand Facts for Civil Engineers in 2004. The overview was developed with support from U.S. EPA and FIRST. This publication is a primer for public agencies, foundries, contractors and others interested in recycling foundry sands in construction projects. Electronic versions of the publication can be downloaded from the Metalcasting Library  or directly from FHWA. Paper copies may be ordered through FHWA’s recycling team or directly from the National Technical Information Service.

Cement Kiln Feedstock 
Foundry sand (with the exception of foundry sand mixed with sodium silicate binders) is an excellent feedstock for the manufacturing of Portland cement. According to the Portland Cement Association, foundry sand is being used by a number of North American cement kilns.  The mineral content and grain size of the sands make foundry sands a good technical fit for cement production. The largest constraint on this use is the limited number of cement kilns in the United States and Canada.  Shipping distances and/or limited quantities may prevent foundries from participating in the cement kiln market. The American Foundry Society is working with the Portland Cement Association to increase the use of foundry sands in Portland cement production.

Flowable Fill
Foundry sand is also an excellent fit as an aggregate substitute in the production of Controlled Low Strength Material (CLSM), a type of low strength concrete specifically designed to be excavatable.  This product, which is usually produced by ready mix concrete companies, is commonly referred to as Flowable Fill.  A number of research studies document the technical fit for foundry sand in this application, where neither the color, clay content nor grain size is a detriment.  Flowable fill is able to use large volumes of foundry sand because a ton of foundry sand can be used per cubic yard of CLSM.  Foundry sand will usually be less expensive than other local aggregate sources. The principal business constraint is that many ready mix producers do not have a separate storage bin or silo for foundry sand or have not developed mix designs incorporating their local foundry sands.  Smaller foundries may not be able to meet the volume requirements for a concrete ready mix plant but may be able to blend their sands with other sources to meet requirements. 

The U.S. EPA has a Comprehensive Procurement Guideline   in place requiring the use of flowable fill containing foundry sand and/or coal ash in projects with more than $10,000 in Federal funding.   Regrettably, CPG’s are rarely enforced, and many public sector projects using flowable fill are built without the benefit of foundry sand.  This is an excellent opportunity to increase the use of foundry sand in sustainable development projects. The FY2007 Energy Bill contained a provision requiring EPA and other Federal departments to enforce the CPG’s on the inclusion of recycled materials in cement and concrete.  Foundry sand is one of the “recovered mineral components” referenced in Section 108 of the bill.  U.S. EPA undertook a Congressionally-mandated 30 month study to assess how to increase the use of industrial materials in these products. A copy of Report to Congress: Study on Increasing the Usage of Recovered Mineral Components in Federally Funded Projects Involving Procurement of Cement or Concrete (PDF) can be downloaded from EPA’s website or from the Metalcasting Library. Although the majority of the report deals with Coal Combustion Products (CCP’s), the report also concludes that foundry sand could be more broadly used in cement and concrete applications.

Manufactured Soils
A growing use for some foundry sands is as a component in the manufacturing of topsoil.  In many parts of the country, high quality topsoils for landscaping are not available.  Commercial landscapers and nursery growers frequently manufacture topsoil by blending composted materials and low quality soils.  Most bagged topsoil sold in garden centers and home improvement centers is manufactured topsoil.  Specialty turf applications are also a potential market for some foundry sands.  Foundry green sands are of particular interest to soil blending companies because of their dark color, clay content, moisture retention, and consistency.  

A number of research studies have shown that many foundry sands are “cleaner than dirt” with respect to the presence of potentially harmful metals.  For more information and references to these studies, please visit the Environmental Profile section as well as the Manufactured Soils page of the Applications section. In a comprehensive effort, the Agricultural Research Service (ARS), an arm of the U.S. Department of Agriculture, initiated a multi-phase peer-reviewed research project to assess the safety and suitability of foundry sands for soil-related applications.  U.S. EPA then partnered with USDA-ARS to produce a peer-reviewed risk assessment study of metalcasting sands. U.S. EPA concluded, as earlier studies had done, that segregated iron, steel and aluminum facility sands are comparable to, or sometimes “cleaner” than, background soil levels and are safe to use in manufactured soils.

Other Applications
Metalcasting facility sands can replace a portion of the fine aggregate in many other types of applications and markets, all of which exist at a commercial scale in the U.S.  These applications and markets include the following:

Hot Mix Asphalt
Ready mix concrete
Precast concrete products
Bricks and pavers
Grouts and mortars
Landfill daily cover
Landfill construction material 
Information about these and other uses for FS can be found under Applications.