Extracting Lithium from Salt Lake: why adsorption stands out

The market price of lithium carbonate rose sharply in 2017, reaching a peak of 180000 / ton in December. At that time, extraction technology and rapid industrialization became the key to attack the city and pull out the stockade. In the market where the supply of lithium carbonate was still dominated by ore lithium at that time, the extraction of lithium from salt lake brine was still in the exploratory stage of the coexistence of various technologies, such as calcination, extraction, electrodialysis, precipitation and so on. The adsorption method introduced by Lanxiao Technology is only one of various theoretical schemes.

So in the following years, why did adsorption come to the fore and become the mainstream technology in the construction of new production lines?

This is first of all due to the natural advantages of adsorption. Adsorption is suitable for selective adsorption of specific components in liquid environment, and high selectivity is its absolute competitive advantage.

In nature, many substances accompany each other, such as gallium ions in alumina mother liquor and magnesium and lithium in salt lake brine. The purpose of adsorption is to find the extremely subtle and almost unique difference in structure between these "twin brothers", and to study and design adsorbents with excellent functions, which can adsorb one component and let go of other components at the same time. This may be achieved through the complex pore structure of the adsorbent, or through the functional group added to the adsorbent, which can capture the target in a directional and highly selective manner, while allowing other components to flow through the resin column. For example, gallium adsorbents let aluminum ions flow while gallium ions are adsorbed efficiently, while lithium adsorbents let magnesium ions flow while adsorbing lithium ions efficiently.

When the resin column absorbs the target, it can be washed with water or some liquid to rinse the target out of the resin. In this way, on the one hand, the target is collected; on the other hand, the adsorbent is reborn and enters the next working cycle.

Therefore, the principle of adsorption seems simple, but its core is to study and design a unique adsorbent.

While achieving the above separation purposes, adsorption has the following advantages: 1. In the production process, it does not need to use a large number of acidic or alkaline solvents, so it is very friendly to the environment. This is of great significance in industrial production under the background that environmental protection has become a global consensus, and it is especially suitable for areas with particularly fragile natural environments, such as Qinghai and Tibet. 2. The adsorption method is suitable for automatic production, producing the same output, greatly shortening the working time and high production efficiency, which is the basis of industrial production. 3. The high selectivity of adsorption determines its high degree of separation. 4. Due to the designability of the adsorbent, it has obvious advantages in improving the quality of lithium carbonate and reducing the production cost, and has the potential for continuous improvement.

In the technical scheme and industrialization project provided by Lanxiao Science and Technology for lithium extraction from salt lake, the adsorption method effectively reduces the ratio of magnesium to lithium and achieves the best lithium extraction effect. Coupled with the technical transformation units such as impurity removal and recovery of adsorption technology, it is the maximum utilization of salt lake resources.

The adsorption technical scheme provided by Lanxiao Science and Technology for lithium extraction from salt lake has both economic benefit and environmental protection, and it is a new industry of circular economy and sustainable development.