CN-121976038-A - Solar lithium enrichment device and method based on magnesium-calcium selective barrier

CN121976038ACN 121976038 ACN121976038 ACN 121976038ACN-121976038-A

Abstract

The utility model provides a solar energy enrichment lithium device and enrichment lithium method based on magnesium calcium selectivity separation, including rich lithium salt collection subassembly, it is last bottom face closure, lower bottom face opening, integrated into one piece's mesa cavity structure, the projected area of lower bottom face is greater than the projected area of last bottom face, the circumference edge of lower bottom face is equipped with the cell type binding off that extends along its profile, side water layer wearing mouth that is parallel to each other has been seted up on the last bottom face of rich lithium salt collection subassembly, middle water layer wearing mouth has been seted up between the side water layer wearing mouth that is parallel to each other, side water layer wearing mouth is mutually perpendicular with middle water layer wearing mouth, water salt transport subassembly is worn to establish respectively in side water layer wearing mouth and the middle water layer wearing mouth, be provided with photo-thermal subassembly on the water salt transport subassembly on the upper bottom face. The problems that the membrane is easy to be scaled and polluted under a high-salt complex system, the membrane material cost is high, the solid waste pollution is easy to be caused by waste membranes, and the system energy consumption and the equipment complexity are improved due to the high operation pressure difference are solved.

Inventors

WANG TIANYI
LI MINGHAO
WANG JIAYING
ZHOU XIANXU
QUE WENXIU
YANG YAWEI
ZHOU MO
Du Xinyin
LIU YIHONG
SHEN YUYAO
XIE HAOJIE
DU KAIJUN
XU HAO

Assignees

西安交通大学

Dates

Publication Date: 20260505
Application Date: 20251223

Claims (10)

1. The solar energy lithium enrichment device based on magnesium-calcium selective blocking is characterized by comprising a lithium enrichment salt collecting assembly (1), a water salt conveying assembly (2) and a photo-thermal assembly (3); The lithium-rich salt collecting assembly (1) is of a table-shaped cavity structure with a closed upper bottom end face, an open lower bottom end face and an integrated structure, the projection area of the lower bottom end face is larger than that of the upper bottom end face, the circumferential edge of the lower bottom end face is provided with a groove-shaped closing opening extending along the outline of the lower bottom end face, the upper bottom end face of the lithium-rich salt collecting assembly (1) is provided with side water-conveying layer penetrating openings (1.1) which are parallel to each other, a middle water-conveying layer penetrating opening (1.2) is formed between the side water-conveying layer penetrating openings (1.1) which are parallel to each other, the side water-conveying layer penetrating openings (1.1) are mutually perpendicular to the middle water-conveying layer penetrating openings (1.2), the side water-conveying layer penetrating openings (1.1) are respectively penetrated with the water-salt conveying assembly (2), the water-salt conveying assembly (2) which is positioned on the upper bottom end face is provided with a photo-thermal assembly (3), the side water-conveying layer penetrating openings (1.1) which are parallel to each other are opposite to each other, and the water-conveying salt collecting assembly (1.3) is positioned on the surface of the lithium-rich salt collecting assembly; The water and salt transportation assembly (2) comprises a side water conveying layer (2.1) and a middle water conveying layer (2.2), wherein the side water conveying layer (2.1) and the middle water conveying layer (2.2) are correspondingly penetrated through the side water conveying layer penetrating opening (1.1) and the middle water conveying layer penetrating opening (1.2), one ends of the side water conveying layer (2.1) and the middle water conveying layer (2.2) extend into the cavity of the lithium-rich salt collection assembly (1) to be in contact with salt water, the other ends of the side water conveying layer and the middle water conveying layer are clung to the side wall surface of the lithium-rich salt collection assembly (1), one end of the water and salt transportation assembly (2) extending into the cavity of the lithium-rich salt collection assembly (1) is sleeved with a divalent ion shielding layer (2.3), the position of the divalent ion shielding layer (2.3) is at least 5mm higher than the liquid level, and one end of the side wall surface of the water and salt transportation assembly (2) clung to the salt collection assembly (1) is in a trapezoid shape with a short bottom edge and downward; The photo-thermal assembly (3) comprises a photo-thermal layer (3.1) and a waterproof moisturizing layer (3.2), and the photo-thermal layer (3.1) and the waterproof moisturizing layer (3.2) are sequentially arranged on the water salt transport assembly (2) from top to bottom.
2. The solar energy lithium enrichment device based on magnesium-calcium selective blocking according to claim 1, wherein the width of the middle water conveying layer (2.2) is larger than that of the side water conveying layers (2.1), and the upper bottom end face of the lithium salt enrichment collection assembly (1) is paved with the middle water conveying layer (2.2) and the side water conveying layers (2.1) together.
3. The solar energy lithium-enriched device based on magnesium-calcium selective blocking according to claim 1, wherein the divalent ion shielding layer (2.3) has a height of 2-5 mm and a thickness of 1-3 mm.
4. The solar energy lithium enrichment device based on magnesium-calcium selective blocking according to claim 1, wherein the material of the divalent ion shielding layer (2.3) is at least one of zeolite molecular sieve or alkaline cement, the alkaline cement is 325 white cement, 425 white cement, 525 white cement or gray cement, and the zeolite molecular sieve is 4A, 5A or 13X zeolite.
5. The solar energy lithium-enriched device based on magnesium-calcium selective blocking according to claim 1, wherein in the trapezoid structure, the long bottom edge and the height are equal in size, and the size ratio of the long bottom edge to the short bottom edge is 2:1-5:1.
6. The solar energy enrichment lithium device based on magnesium-calcium selective blocking according to claim 1, wherein the lithium-rich salt collecting component (1) is nylon foam, polyethylene foam or aerogel heat insulation board, the water salt transporting component (2) is hydrophilic fiber cloth, the photo-thermal layer (3.1) is a black inorganic coating with light absorption property, and the waterproof moisture-preserving layer (3.2) is an ethylene flexible membrane material.
7. The lithium enrichment method of a solar energy lithium enrichment device based on magnesium calcium selective blocking according to any of the claims 1-6, comprising the steps of: s1, adding a lithium-containing salt solution to be treated into a cavity of a lithium-rich salt collecting assembly (1), wherein the lithium-containing salt solution is contacted with one end of a side water conveying layer (2.1) and a middle water conveying layer (2.2) in a water salt conveying assembly (2) extending into the cavity; S2, carrying out capillary transport on the lithium-containing salt solution along the side water conveying layer (2.1) and the middle water conveying layer (2.2), selectively blocking divalent metal ions by the divalent ion shielding layer (2.3) when the solution flows through the divalent ion shielding layer (2.3), and continuously carrying out upward transport along the side water conveying layer (2.1) and the middle water conveying layer (2.2) along with the solution, so as to obtain the lithium-rich solution at the upper bottom end surface of the lithium-rich salt collecting assembly (1) and realize separation of lithium ions and divalent metal ions; S3, under the irradiation of sunlight, the photo-thermal assembly (3) converts solar energy into heat energy, so that a lithium-rich solution is gradually enriched and evaporated on the upper bottom end surface of the lithium-rich salt collecting assembly (1), the lithium-rich solution is continuously evaporated on the outer surface of the side wall of the lithium-rich salt collecting assembly (1) along the side water conveying layer (2.1) and the middle water conveying layer (2.2), and lithium-rich salt solids are separated out from a groove-shaped closing-in of the lower bottom end surface of the lithium-rich salt collecting assembly (1) and collected; S4, dissolving the lithium-rich salt solid collected in the step S3 in water, adding a carbonate precipitant into the solution, precipitating and separating out lithium ions in a lithium carbonate form by adopting a single-step carbonate precipitation method, and obtaining separated and purified lithium salt after solid-liquid separation, washing and drying.
8. The method for enriching lithium by using a solar energy device based on selective blocking of magnesium and calcium according to claim 7, wherein in the step S4, the lithium-rich salt solid is added into water to form a lithium-rich salt solution with the mass fraction of 10-25 and wt%, the lithium-rich salt solution is heated to 60-90 ℃, a carbonate precipitant is added under stirring, the actual addition amount of the carbonate precipitant is 1.02-1.10 times of the theoretical reaction equivalent of the carbonate precipitant according to the mole number of lithium ions in the lithium-rich salt solution, after solid-liquid separation, the filter cake is washed for 1-3 times by adopting deionized water/desalted water with the mass fraction of 50-95 ℃, and then the filter cake is dried at 110-130 ℃ for 2-12 h.
9. The lithium enrichment method of the solar energy lithium enrichment device based on magnesium-calcium selective blocking according to claim 7, wherein when the divalent ion shielding layer (2.3) reaches adsorption saturation or performance is reduced, the water salt transport assembly (2) is integrally taken out, and the divalent ion shielding layer (2.3) is separated from the side water conveying layer (2.1) and the middle water conveying layer (2.2) in an axial slipping mode for replacement.
10. The method for enriching lithium of a solar energy enriched lithium device based on magnesium-calcium selective blocking according to claim 8, wherein the preferred mass fraction of the lithium enriched salt solution is 12-20 wt%, and the preferred anhydrous sodium carbonate is carbonate as carbonate precipitant.

Description

Solar lithium enrichment device and method based on magnesium-calcium selective barrier Technical Field The invention belongs to the technical field of salt lake brine treatment and inorganic salt separation, and particularly relates to a solar lithium enrichment device and a lithium enrichment method based on magnesium-calcium selective blocking. Background In recent years, with the continuous development of solar energy utilization technology, solar energy interface evaporation technology has been receiving a great deal of attention in the fields of sea water desalination, high-salt wastewater treatment, salting-out recovery and the like because of its remarkable advantages such as simple structure, low energy consumption, direct utilization of natural solar radiation and the like. The technology generally realizes the volume reduction of the solution and the concentration of the solute by constructing a high-efficiency photo-thermal conversion interface so that water molecules are preferentially evaporated at the interface. However, the existing solar energy interface evaporation process mainly relies on phase change mass transfer of moisture, and the acting object is a solution integral system, which essentially belongs to non-selective evaporation behavior. Because solute does not migrate along with steam in the evaporation process, but is passively reserved in a liquid phase, the interfacial evaporation technology does not have the capability of distinguishing different metal ions, and an effective selective regulation and control means is lacked for monovalent metal ions and divalent metal ions, so that high-efficiency separation of lithium ions from divalent ions such as magnesium, calcium and the like is difficult to realize. In lithium resource systems such as salt lake brine, magnesium ions (Mg 2 +) and calcium ions (Ca 2 +) generally exist in a concentration far higher than that of lithium ions, insoluble salts are preferentially separated out in the evaporation concentration process, crystallization behaviors of the lithium salts can be obviously interfered, the purity of lithium products is reduced, and the process difficulty of subsequent separation and purification is increased. Therefore, aiming at the selective lithium salt enrichment based on solar interface evaporation, the core technical problem is not to simply increase the evaporation rate, but to realize effective shielding, removal or separation of divalent ions such as magnesium, calcium and the like in brine in the evaporation process, thereby creating favorable conditions for the enrichment of lithium ions. Aiming at the problems, in the prior art, based on the difference of hydration radius and physical size of different ions in aqueous solution, a membrane material or a filter medium with specific pore size distribution is adopted to physically screen or separate divalent ions such as magnesium, calcium and the like. The method can realize ion separation to a certain extent through aperture regulation in theory, but has a plurality of limitations in practical application. On one hand, the brine system has high salinity and complex components, inorganic salt scaling and organic pollution are easy to occur in the long-term operation process of the membrane material, so that the membrane flux is fast attenuated, the preparation cost of the membrane material is high, the accumulation of waste membranes can cause remarkable solid waste pollution, and on the other hand, a larger operation pressure difference is usually required to be applied to maintain effective separation, so that the energy consumption and the equipment complexity of the system are increased. Disclosure of Invention Aiming at the defects of the prior art, the invention aims to provide a solar energy lithium enrichment device and a lithium enrichment method based on magnesium-calcium selective blocking, which have simple structure, can rely on natural solar energy to drive, can realize divalent ion blocking in the evaporation process, improve the lithium ion enrichment degree, and solve the problems that the membrane is easy to scale and pollute under a high-salt complex system, the membrane material cost is high, the waste membrane is easy to cause solid waste pollution, and the system energy consumption and the equipment complexity are improved due to the need of high operation pressure difference. In order to achieve the above purpose, the technical scheme provided by the invention is as follows: a solar energy enrichment lithium device based on magnesium-calcium selective blocking comprises a lithium-rich salt collecting component, a water salt transporting component and a photo-thermal component; The lithium-rich salt collecting assembly is of a table-shaped cavity structure with a closed upper bottom end face, an open lower bottom end face and an integrated structure, the projection area of the lower bottom end face is larger than that of the upper bottom end