SBIR Phase I: Separation of Clean Gypsum from Phosphate Ore Processing Waste

The broader/commercial impact of this Small Business Innovation Research (SBIR) Phase I project is in safe and economic isolation and disposal of radioactive components of phosphogypsum (PG), a problematic waste byproduct of fertilizer production, and converting the remainder waste into economically viable chemicals such as calcium carbonate & ammonium sulfate while recovering rare earth elements (REE). Currently, over 70 million tons of PG are produced each year, with over 1 billion tons stored in Florida alone. Improper storage risks contaminating groundwater and harming nearby communities by allowing radioactive elements and heavy metals to leach into aquifers. Moreover, radium in PG can decay into radon, a carcinogenic gas. The proposed innovation aims to address those environmental risks directly and offers substantial commercial opportunity by generating up to $50 million in annual revenue per processing facility, cleaning and converting over 200,000 tons of PG per year. Thus, this innovation addresses a pressing need for sustainable waste management, mitigates groundwater contamination risks, and transforms problematic waste into economically viable resource. PG is a byproduct of phosphoric acid production and includes naturally occurring radionuclides, making the material radioactive. These radionuclides are found in phosphate rock and are mostly uranium, thorium, and radium. This project focuses on developing an innovative, eco-friendly process technology that employs double salt formation using one or more ionic salt solutions to release all the contaminants from the gypsum crystal structure. After separating the double salt from those contaminants, gypsum is regenerated and converted into ammonium sulfate and calcium carbonate through the company’s proprietary process that uses flue gas as a source of CO2. The contaminants can be either separated or disposed of safely. The project aims develop process conditions that achieve consistently high separation efficiency for broad range of PG feedstocks. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.