Beihuo Salt Lake
Lithium-brine is an important potential source of lithium. Much research and investigation has been carried out aimed at lithium recovery from brine and a study was carried out to explore the lithium migration behaviour during brine evaporation and production process at Beihuo Salt Lake. Results showed that, for Beihuo brine mined from the Qinghai region, most lithium was enriched in the residual brine during the brine evaporation process. The concentration of lithium in the residual brine could be more than 400 mg/L. More than 99.93% lithium ions in residual brine exist in free ions state and lithium does not precipitate from brine with a density of 1.3649 g/mL.
The investigation results provide a theoretical basis for comprehensive development and utilization of lithium resources in Beihuo Salt Lake. Salt lake brine, thermal spring, and oilfield water are important geological sources of lithium. The commercial exploitation of the lithium brine began at the Searles Lake in the United States in 1936. Since then, more focus has been placed on recovering lithium from salt lake brine because of its low economic cost and low environmental impact.
As a country possessing huge amount of brine, China accounts for one-third of the world’s liquid lithium reserves. In China, most lithium-rich lakes are located in the Qinghai-Tibet plateau. Among them, Qarhan region is the biggest, containing significant lithium reserves estimated at 1.64 million tonnes. Qarhan has promising research value and development prospects of lithium resource in the near future.
Our researchers recently developed new methods of extracting lithium from natural brine sources —
revealing that the new methods allow for an increase in the purity of the recovered lithium
solution from around 95% all the way up to 99.9%. Accomplishing such a high degree of purity through traditional methods is much more difficult and resource intensive. In this process, we are typically able to purify 99–100% of calcium and also over 90% of magnesium. Lithium loss only amounts to 3–5%, compared to traditional methods, where the purification outcome is weaker and the lithium loss is more considerable. The extraction process we use is more expensive than regular precipitation, but, as our research shows, separation is more efficient and easier.
Out tests in the region (see below) indicate a rich lithium deposit. Supported by a relatively low
presence of magnesium, this simplifies the overall process, making this project not only feasible, but economically lucrative.
Lithium is critical for the current global paradigm-shift to electrification of transport, stationary storage and renewable energy.
Lithium in the form of salt lake brine which can be easily processed using off-the-shelf, commercially proven technologies to produce lithium carbonate.