Sand is essential for our casting process.

Columbia craftspeople put the finishing touches on sand molds and cores for our castings.

93,000 Tons of Our Recycled Material Was Re-Used at Landfills and Construction Sites Last Year.

Sand plays a critical role in our work at Columbia Steel. As we manufacture wear parts, we use sand mixed with a small amount of bentonite clay, corn meal and water to form a mold that gives the molten steel form as it cools into a casting. After each new piece is cast, cooled, and removed from the mold, we’re able to recapture and reuse most of that sand in future molds. Eventually, this reused product becomes less effective, and we replace it with new sand.

Steel foundries across the country use this same technique in their manufacturing processes, which creates lots of excess sand. In 2007, the American Foundry Society estimated that the industry generates 10 million tons of spent foundry sand every year — the majority of which ends up in landfills. We don’t have to discard this product, however. Unlike some manufacturing byproducts, our spent foundry sand is clean and environmentally friendly.

As an alternative to merely throwing this product away, spent foundry sand and slag (a byproduct of the metal melting process) can instead serve as a cost-effective and green alternative fill material in many applications.

As we all look for opportunities to decrease our environmental impact, Columbia Steel is increasing our efforts to recycle as much of our used sand and slag as possible. Here’s how our program works.

Columbia Steel Recycles Our Sand and Slag

Our virgin foundry sand is made from natural Olivine rock that is mined in Washington State, then crushed and screened before we use it to make our molds. We use Olivine rock and not Silica sand, because it is much less hazardous to the respiratory system.

Once the sand has made its way through our manufacturing processes, we thoroughly test the leftover sand and slag to ensure it meets the Oregon Department of Environmental Quality’s (DEQ) beneficial use determination (BUD) criteria for non-residential construction fill.

Potential Uses for Recycled Sand

Recycled foundry sand and slag is a versatile product for several applications, including:

> Road base
> Underground storage tank removal
> Basement fill
> Backfill
> Trenches
> Pipe base
> Retaining walls
> Landfill alternative daily cover

Using these products does come with a few DEQ requirements. First, the fill material must be placed above normal groundwater levels and not in wetlands, lakes, streams or other sensitive environmental zones. The DEQ also requires covering the fill material with asphalt, concrete, soil, sand or crushed rock after they finish the job. With these simple requirements, the recycled products are a wonderful green alternative that is cost-efficient and effective.

Who Uses Our Recycled Products?

Columbia Steel sends 10,000 tons of recycled sand and slag to sites throughout the region in a typical year. We have several ongoing customers, including a landfill that uses 550 tons of our material each month as an alternative daily cover. We also fill one-time orders for projects of all sizes. For instance, in 2020 our recycled material shipped to construction projects totaled 93,000 tons, thanks mostly to just one large construction project.

The Benefits Begin to Add Up

Part of what makes our products so attractive is how well they compare to traditional fill material. For starters, recycled sand is more economical to use. One of the most common fill materials is 3/4 inch minus gravel, which currently costs in the range of about $14 per ton in the Portland/Vancouver area. Columbia’s equivalent recycled product, on the other hand, can be had for one quarter the cost. Savings of that magnitude can make a significant difference in a project’s bottom line.

Our recycled material also performs just as well as new products. For example, independently tested compaction data for our recycled equivalent product is nearly identical to newly mined 3/4 inch minus gravel.

Perhaps most importantly, using a repurposed product to fill a project need is a greener choice. Instead of mining new crushed rock, which uses up precious natural resources, builders can opt for recycled materials that achieve the same results. In the age of environmental consciousness, businesses are searching for these opportunities wherever they can find them.

Investing to Improve Impact

Our recycled sand and slag operation is just one of the many ways we’re reducing our environmental impact. Over the years, we’ve invested in equipment upgrades that improve our ability to recapture and reuse foundry sand within our own operation. These process improvements allow us to use less new sand while also throwing away less spent sand.

More recently, we’ve expanded these environmentally friendly practices outside our walls so that other industries can benefit from using recycled products. We believe that once people discover how affordable and effective these materials are, they won’t go back to using traditional fill material.

If you are interested in purchasing our recycled sand and slag, contact Dave Faust, Columbia Steel’s Environmental Manager, at 503.286.0685 ext. 200 or by email at [email protected]