The Mechanism of Adsorption of Lithium Hydroxide-Based Lithium Adsorbent from Brine by Northwest Research Institute
Lithium is a metal element with strong electrochemical activity. It is a new type of energy and strategic resource of great significance in the construction of national economy and national defense. It is called "energy metal that promotes world progress." Lithium brine resources account for about 2/3 of the global total lithium resources. The cost of preparing lithium products using lithium-containing brine as a raw material is lower than that using lithium ore as a raw material. Lithium-containing brine extracts lithium has attracted more and more attention. In recent years, brine extracts lithium The technology has achieved significant innovation and progress, and lithium brine extraction enterprises have also achieved considerable economic benefits. In high-salt brine, trace lithium is associated with constant elements such as potassium, sodium, magnesium, and calcium. For salt lake brines with low lithium content and high magnesium-to-lithium ratio, it is difficult and costly to directly apply precipitation methods, and the adsorption method is more realistic. One of the feasible methods. The aluminum hydroxide-based lithium adsorbent is the only adsorbent that is industrially applied when the lithium is extracted from the salt lake brine by the adsorption method. The adsorbent has a moderate adsorption rate and adsorption capacity, good selectivity and recycling performance, and low preparation cost. . Although aluminum hydroxide-based lithium adsorbents have been industrially used in the extraction of lithium from salt lake brines, the mechanism of adsorption is not very clear. The research team of Wu Zhijian from the Salt Lake Resource Chemistry Laboratory, Qinghai Salt Lake Research Institute, Northwest Institute of Eco-Environmental Resources, Chinese Academy of Sciences (preparation) conducted work on the preparation, adsorption performance, adsorption mechanism and adsorption separation process of aluminum hydroxide-based lithium adsorbent, and comprehensively analyzed The preparation, adsorption and desorption performance of aluminum hydroxide-based lithium adsorbent, the structure and morphology changes after adsorption and desorption of the adsorbent, the adsorption mechanism was analyzed in depth. Lithium ions are likely to be adsorbed into the octahedral cavity in the aluminum hydroxide layer in the form of bare ions. To balance the charge, chloride ions enter the interlayer. The sieving effect and the difference between lithium ion and other ion hydration are the main reasons why the adsorbent has better selectivity for lithium. Although the bare ion radius of Mg2 + and Li + is very close, the charge of Mg2 + is twice that of Li +, and there is a significant difference between the two ions and the water molecule. Mg2 + and water molecules form a tightly bound complex ion [Mg (H2O) 6] 2+, while Li + and water molecules can only form water and ions with a hydration number of 5, and the free energy of Mg2 + hydration 4 times larger than Li +. In the process of being adsorbed, Li + is easier to get rid of water molecules and be adsorbed than Mg2 +. For details, please refer to “Salt Lake Researchâ€, Issue 3, 2018, “Research Highlights†on pages 1-6. Naips LED Emergency Ceiling Light-A power failure light with a modern design that provides high quality lighting with an adjustable cct color switch attached to each fixture. Every round light fixture is pre-installed with the built-in lithium ion emergency batterry pack, damp location rated for reliability, ETL listed for your safety, is 85-265V AC input, has a brushed chrome finish, and backed by a 5 YEAR WARRANTY. Led Emergency Ceiling Light,Emergency Led Ceiling Light,Emergency Light For Ceiling,Emergency Light Ceiling Type Foshan Nai An Lighting Electric Co.,ltd , https://www.fsnaipsled.com
The structure of gibbsite octahedron (a: (100) plane projection, b: (001) plane projection). 
XRD patterns of adsorbent (a, b, and c correspond to the adsorbent before, after, and after elution, respectively).