Solution Mining Of Nahcolite At The American Soda Project, Piceance Creek, Colorado

American Soda, LLP has commissioned the first solution mine for recovery of naturally formed sodium bicarbonate (nahcolite) from low-grade deposits using high-pressure, high-temperature injection fluid. This project, known as the Yankee Gulch Project, was commissioned33 years after discovery of the deposit and followed an intensive four-year feasibility study that included a full-scale pilot test. The nahcoliteis co-mingled with oil shale and is impermeable. Solution mining is achieved by a combination of thermo-mechanical cracking and dissolution. Elevated temperatures are required to initiate the thermally induced cracking and to enhance solubility of the nahcolite, which is highly temperature dependent. This paper will provide an overview of the development of the project from discovery, characterization, pilot testing, permitting and commissioning, with emphasis on the solution mining aspects.