Method description of TOP extractant


Release time:

2022-11-01

Source:

network

In the field of TOP extraction technology, in particular, a lithium ion system includes a lithium ion separation device for the aqueous phase containing lithium ions, including tributyl phosphate and ionic liquid. The volume ratio of the ionic liquid to the tributyl phosphate is not higher than 1:1; And a high acid salt added to the stock solution containing lithium ions to promote, the ratio of the amount of the high acid salt to the amount of the lithium ion species is 0.5 to 3:1. The invention not only avoids the environmental pollution caused by traditional organic solvent, reduces the dissolution loss caused by volatilization, but also overcomes the problem of difficult separation of organic phase and water phase, and has a good application prospect.

Method description of TOP extractant

In the field of TOP extraction technology, in particular, a lithium ion system includes a lithium ion separation device for the aqueous phase containing lithium ions, including tributyl phosphate and ionic liquid. The volume ratio of the ionic liquid to the tributyl phosphate is not higher than 1:1; And a high acid salt added to the stock solution containing lithium ions to promote, the ratio of the amount of the high acid salt to the amount of the lithium ion species is 0.5 to 3:1. The invention not only avoids the environmental pollution caused by traditional organic solvent, reduces the dissolution loss caused by volatilization, but also overcomes the problem of difficult separation of organic phase and water phase, and has a good application prospect.

Lithium is not only important in the national defense industry, but also increasingly important in the national economy, especially in the energy field: sLi and 7Li are the fuel for future nuclear fusion reactors and important materials for nuclear fission reactions; The demand for battery materials is also growing. Therefore, lithium is known as the "energy metal of the 21st century". The demand for lithium at home and abroad continues to grow, and the research, development and utilization of lithium resources are extremely urgent.

At present, the main technical methods for extracting lithium from salt lake brine include evaporation crystallization separation, salting out, selective semi permeable membrane, precipitation, solvent TOP extraction, ion exchange, etc. Among them, the solvent TOP extraction method is an effective method for extracting lithium from low-grade brine, which can realize the selection of target ions, especially for salt lake brine with high magnesium lithium ratio. At present, most of the TOP extractants used are phosphorus containing organic TOP extractants, amine TOP extractants, diketones, crown ethers and mixed TOP extractants, among which phosphorus containing organic TOP extractants are mostly studied. The commonly used TOP extraction system uses tributyl phosphate (TBP) as the TOP extractant, ferric chloride as the co TOP extractant, and sulfonated kerosene as the diluent. The extraction of lithium with tributyl phosphate as the TOP extractant has a high TOP extraction rate (the total recovery rate of lithium is about 90%), a simple process flow and a very broad application prospect.

Ionic liquids (ILs) have some properties: (1) almost no vapor pressure, no volatility, no combustion, no oxidation, and adjustable viscosity; (2) Ionic liquid is a good solvent for many organic compounds, organometallic compounds, inorganic compounds, and even polymer materials. It can provide non-aqueous two-phase systems with adjustable polarity, and can be used as a co soluble phase of water in the non chemical separation process; (3) Stable to water and air, easy to handle and recover. Ionic liquid is environment-friendly, pollution-free, reusable, and can be used for TOP extraction and separation.

When solvent is used to extract lithium from salt lake brine system, the commonly used TOP extraction system consists of tributyl phosphate (TBP), ferric chloride and sulfonated kerosene. However, the disadvantage of this method is that ferric chloride is easier to be emulsified as a co agent during operation, which makes it difficult to separate the middle water phase from the organic phase.