Extending the rate of hydration and setting time is the secret to improving the strength and quality of Portland cement. That is where gypsum comes in. Gypsum is used as a setting agent in the manufacture of Portland cement, and 5 - 10% of the finished Portland cement product is gypsum.
The reason recycled gypsum has not traditionally been used in cement manufacturing up to this point is because of its tight specifications and low tolerance for contamination.
After going through the GypStream, the gypsum is clean enough to meet the requirements for cement manufacturing and presents another market opportunity for recycled gypsum.