Just laying out the science here for all doubters to ponder. The following is taken from PEN's
research note and is one of the reasons I believe the management can deliver.
p.8: In contrast, the carbonate content of the host sands at the Ross ISR Project is low (Knode 2017).
p.11-12: Using inadequate acid or gradually changing the pH during low pH ISR increases the gypsum precipitation potential. Adding acid at a higher initial concentration, such as used in Strata leach tests, rapidly reduces the pH and minimizes the 12 risk of formation plugging due to gypsum precipitation. This is verified in Kazakhstan ISR operations (see Section 2.5), where low pH ISR has not resulted in irreversible well or formation plugging due to gypsum precipitation despite a relatively high carbonate content in the mineralized sandstones.
p.17: Operations at uranium ISR mines in Kazakhstan typically follow a standard design used by Kazatomprom (CSA 2013). Solutions are pumped from the wells to the plant or ponds, then processed using ion exchange, denitrification, precipitation, and yellowcake drying. Irreversible well or formation plugging due to precipitation of gypsum are not known to be issues at these facilities. Gypsum precipitation is operationally controlled through the injection of hydrochloric or nitric acid or through mechanical well stimulation such as airlift pumping or pneumatic-impulse treatment (Gorbatenko 2013). The ISR process in Kazakhstan is generally similar to that used in Australia and the United States, except that more acid is generally used per pound of uranium produced in Kazakhstan compared with Australia due to higher carbonate content (WNA 2017).
p.32: Strata management has operational experience using low pH lixiviants in Australia and Kazakhstan—this experience would allow Strata to overcome the Wyoming R&D project injectivity issues, which were related to lack of operational experience, by using proven low pH ISR technology such as proper well construction techniques, rapid decrease in pH, and maintaining a stable pH throughout operations. Further, the ionic strength of the production aquifer groundwater is much lower than that in typical Australia projects where gypsum precipitation has been a concern. The typical TDS is 1,200-2,500 mg/L at Ross, compared with TDS levels of 3,000-20,000 mg/L at the Australian projects.
