Wastewater from shale operations in Pennsylvania could provide up to 40pc of US lithium demand if tapped, according to a study from the University of Pittsburgh (UoP).
Wastewater produced from oil and gas extraction in the region is rich in lithium and could provide an environmentally sound way to extract lithium without needing large open-pit mines or brine fields, with the added benefit of recycling water resources.
"This study estimates that Marcellus Shale-related Li yields have potential to make a significant contribution to US domestic consumption with a set of reasonable, conservative assumptions," according to the research article published in Scientific Reports last month.
"Wastewater from oil and gas is a burgeoning issue," National Energy Technology Laboratory researcher Justin Mackey said. "Right now, it's just minimally treated and re-injected. But it has the potential to provide a lot of value. After all, it's been dissolving rocks for hundreds of millions of years — essentially, the water has been mining the subsurface."
Large oil companies have recently invested into lithium extraction, potentially bringing their technological knowledge and shale experts and applying them to a new industry.
Norwegian state-controlled Equinor recently invested into underground lithium brine extraction in Canada and ExxonMobil expects to produce from brines in Arkansas by 2027.
US lithium resources have been expanding with large discoveries in the past few years. Large clay deposits have been found in the McDermitt Caldera region on the Nevada-Oregon border, as well as multiple underground brine resources at the Smackover formation, Arkansas. The former attracted the ExxonMobil investment.
The US geological survey estimates US lithium reserves at 1.1mn t, the fifth largest in the world after Chile, Australia, Argentina and China (see graph), with negligible production in 2023.
