Grants and Contributions:

Grant or Award spanning more than one fiscal year (2017-2018 to 2018-2019).

Lithium extraction from brine is conventionally achieved by the removal of magnesium, calcium, and barium,x000D
which have similar chemical behaviors to lithium, followed by solar evaporation in a pond to concentrate andx000D
precipitate lithium compounds. Although this approach benefits from a relatively low-cost and simplex000D
operation, evaporation of large volumes of water in cold regions such as Alberta is neither economicallyx000D
feasible nor environmentally benign. In this project, we will investigate lithium extraction from brine waterx000D
using unconventional approaches, predicated on the selective scavenging of lithium ions without resorting tox000D
solar evaporation ponds. One of the few identified lithium extractants is tributyl phosphate (TBP), which hasx000D
been used widely in nuclear chemistry to process spent nuclear fuel. In our study, the first objective is to fullyx000D
characterize the geochemistry of the brines. The second objective is to extract lithium directly from the brine byx000D
TBP using two approaches: (1) utilizing TBP as a solvent, followed by recycling TBP by stripping the lithiumx000D
from it, and (2) hybridizing TBP with organic particles and employing them in a sorption column to selectivelyx000D
sequester lithium from the brine. The sorbent can be regenerated in a concentrated acid to efficiently desorb thex000D
lithium ions. Although there is ample literature surrounding TBP as extractant in nuclear waste treatment, therex000D
are few studies dedicated to TBP as lithium scavenger, in most of which TBP is diluted in an organic solventx000D
and used as a solvent extractant. The results from our work could not only equip our industry partner with ax000D
new technique to address lithium extraction from brine but also open a new window into the research on thex000D
selective sequestering of lithium from brine.