Production of Uranium from Seawater Using a Novel Polymer Adsorbent - Process Development and Cost Analysis

Seawater contains about 3 parts per billion of uranium. With a total ocean volume of approximately 1.3109 km3, there is at least 4.5 billion tons of uranium in seawater which is about 1000 times the amount of uranium known to exist in terrestrial ores. Mining uranium from seawater is economically feasibility if an efficient, reusable and low-cost adsorbent could be developed. In the past year, we have produced kilogram quantities of a highly efficient polymer adsorbent (LCW fiber) derived from cheap acrylic fiber (yarn) for extracting uranium from seawater. Gram quantities ofyellowcake(uranium oxide) have been produced using the fiber adsorbent exposed to a laboratory circulating flume system using seawater pumped from the Sequim Bay, Washington. Economic analysis shows a substantial reduction in the overall cost of the production of uranium from seawater using the LCW adsorbent compared to previously published investigations. Although the results obtained so far are encouraging, certain key information and continued manufacturing and process optimization is still needed for developing a competitive commercial process for production of uranium from seawater. The proposed SBIR Phase IIA study intends to obtain this key information with the goal of making uranium production from seawater economically competitive with the land-based uranium mining methods. A major focus will be on continued real-world testing and scaling up of the technology to commercial scale. First, we need to demonstrate the performance of the adsorbent fiber in an actual ocean deployment, using masses of adsorbent anticipated for commercial scale applications. Second, we need to determine how the capacity and adsorption rate varies with temperature, seeking formulations that are highest performing for different seawater temperatures.Co-extraction of other metals from seawater shouldbe examined which could lower the production cost of uranium. Finally, we need to scale-up and optimize the process focusing on developing a process that allows for multiple re-uses of the adsorbent material making this uranium-from-seawater technology economically favorable.