Each year, more and more gypsum manufacturers discover the benefits of recycling gypsum; not only is gypsum fully recyclable, but it can also replace waste management costs with a value-added product, among a few other key advantages.
Considering today’s increasing environmental concern and regulation, it goes without saying that there is immense value in the opportunities provided through processing recycled gypsum.
The Construction & Demolition Recycling Association seems to agree; the group recently formed a dedicated gypsum recycling committee aimed at improving gypsum recovery rates in the industry.
Why Recycle Gypsum?
The main opportunity for recycling gypsum in the construction sector lies in gypsum board. Also known as drywall, sheetrock, or plasterboard, gypsum board is used as ceiling and wall panels in building construction.
Even though the option to recycle gypsum board has long been available, most often, boards are disposed of in landfills as a result of challenges associated with diversion and contamination.
Landfill deposition is problematic because the anaerobic decomposition of gypsum can produce harmful gasses such as hydrogen sulfide. Additionally, the gypsum found in drywall is capable of breaking down clay liners that waste management companies use to prevent toxins from seeping into water systems. Special measures are therefore required at construction and demolition debris landfills in order to prevent these threats to public health, safety, and the environment.
Recycling gypsum provides an excellent alternative to circumvent disposal issues. By recycling gypsum, waste is reduced at its source, thus turning an environmental problem into a business opportunity. In addition, using recycled gypsum versus mined gypsum promotes sustainable manufacturing practices; gypsum recycling allows manufacturers to reduce their emissions and spend less on energy compared to raw gypsum. In addition, because less raw, mined gypsum is required, transportation emissions are also reduced, as is the burden on natural sources of gypsum.
Sources of Gypsum Waste
Gypsum waste can come from a variety of sources in the construction industry, most of which are associated with the production and use of drywall. Plaster and gypsum blocks also contribute to gypsum waste, but to a much lesser degree. Sources of gypsum board waste (and their associated total percentage) include:
- Gypsum Building Construction Waste (64%): The greatest amount of gypsum waste comes from uninstalled gypsum board scraps from building construction sites. This is considered a clean waste, free of contamination.
- Gypsum Post-Consumer Waste – Demolition (14%) and Renovation (10%): Gypsum post-consumer waste occurs when installed ceiling and wall boards are removed during a building’s demolition or renovation. While not as prevalent as processing recycled gypsum from new construction waste, there are a number of U.S. recyclers who accept post-consumer gypsum board waste. The lack of recycling in this category is often due to contamination issues; nails, wall coverings, and so forth must all be separated from the gypsum. Additionally, lead and asbestos contamination concerns associated with older buildings are also an issue.
- Gypsum Manufacturing Waste (12%): Gypsum manufacturing waste is a result of rejected material created during the manufacture of gypsum wallboard products. Most plants recycle this waste stream as part of their waste avoidance protocol.
Recycled Gypsum Products
Gypsum is an exceptional material in that it is endlessly recyclable, meaning it can be continuously recycled to make the same product.
Gypsum board recycling typically begins when construction site waste is brought to a recycling center for processing. The recycling center separates the paper from the gypsum and breaks down the gypsum into a fine powder. The gypsum powder is then ready to be used in recycled gypsum products. Additionally, the screened paper is sorted and processed based on its intended use.
After processing recycled gypsum, there are a number of different products for which recycled gypsum may be used:
- Agricultural Products: Recycled gypsum is an excellent fertilizer and soil amendment. Not only does gypsum loosen compacted soils, but it also increases water infiltration and adds nutrients such as calcium and sulfur back into the soil, making it essential when promoting sustainability in crop production.
- New Drywall: Many gypsum manufacturers utilize gypsum recycling as a material source for new boards. New products containing recycled gypsum are of the same quality as gypsum boards produced using only raw materials.
- Cement: Gypsum is used as an ingredient in cement manufacturing, providing benefits such as reduced setting time.
- Composting: Gypsum can be used as an additive to compost. It is added after the compost is created in order to supply plants with the important nutrients found in gypsum.
- Paper Products: Recycled paper waste from gypsum boards can be used in agriculture, animal bedding, and even ceiling tiles.
Process Development for Recycled Gypsum
The rising pressure to minimize wastes and recover valuable components, gypsum included, has made testing and development facilities critical to advancing beneficial reuse and recovery applications.
The FEECO Innovation Center has been instrumental in assisting companies to develop the processes necessary to convert their recovered gypsum into marketable products.
“The characteristics of recovered gypsum can vary quite a bit,” says Chris Kozicki, FEECO Process Sales Engineer and agglomeration expert. “This can make converting these materials into a market-ready product a little challenging, so we always recommend testing. Testing will tell you if your specific source of gypsum can be granulated into a soil amendment product, for example, and if so, what the process will need to look like in order to consistently produce the product to the desired specification.”
The FEECO Innovation Center offers batch- and pilot-scale testing for granulation (agglomeration), drying, mixing, and high-temperature thermal treatment. In addition to testing on single pieces of equipment, producers have the option to incorporate multiple equipment types into a continuous loop to simulate commercial-scale conditions and gather the data necessary for scale-up.
The information gathered during testing can then be used in the design of commercial-scale equipment to carry out the process.
Gypsum Recycling Moving Forward
The Construction & Demolition Recycling Association (CDRA) recently established a Gypsum Recycling Committee in their effort to improve the recyclability of gypsum wallboard. The committee will foster collaboration between entities involved in each step of the gypsum recycling lifecycle and has already developed a framework of objectives to move the initiative forward.
Among these goals are creating a diversion policy with clear definitions around gypsum wallboard waste, helping to set post-recycled content standards for new drywall production, establishing best management practices to improve waste diversion, and so much more.
Over the years, FEECO has garnered a reputation for bringing value to materials previously considered as wastes. By providing a balance between market and environmental needs, FEECO has developed usable solutions from a wide array of wastes, including those found in the gypsum industry. We offer extensive experience in both the processing and handling of gypsum, from initial feasibility testing and process development, to custom equipment design and fabrication, and even parts and service support for established production lines.
For more information on our experience with gypsum waste solutions, contact us today.