The invention discloses a method for extracting high-value alkali metal from salt lake brine or seawater through membrane extraction-back extraction. The method is implemented through continuous operation and comprises the following steps of: fixing an ion exchange blend membrane in a membrane component, allowing an organic solution containing an extracting agent to contact salt lake brine or seawater which contains alkali metal ions by a first ion exchange membrane, and allowing alkali metal ions to pass through the ion exchange membrane and be combined with the organic solution containing the extracting agent to obtain metal complex; then transmitting an organic solution of the metal complex to a second ion exchange membrane and allowing the organic solution of the metal complex to contact a back extraction solution by the second ion exchange membrane, and allowing the metal ions to pass through the ion exchange membrane to enter the back extraction solution; during membrane extraction-back extraction, and circulating feed liquid, the back extraction solution and the organic solution containing the extracting agent on one side of the first ion exchange membrane, on one side of the second ion exchange membrane and between the first and second ion exchange membranes; and performing back extraction until a certain concentration of the back extraction solution is reached, and separating lithium, rubidium or caesium precipitates to obtain the final product. The invention provides a high-efficiency, low-cost and feasible route for industrial production of alkali metal salts.

Method for extracting alkali metal from salt lake brine and seawater through membrane extraction-back extraction

The invention provides a method for extracting lithium salts in lithium-containing brine Lithium is extracted through a co-extraction agent, an extraction agent and a diluent, wherein the extract is a mixture of an amide compound and a neutral phosphorus oxide compound, the structural formula of the amide compound is shown in the specification, and the structural formula of the neutral phosphorus oxide compound is shown in the specification The method provided by the invention further optimizes the properties of extracted lithium, so that the method is more applicable to the industrial application

Method for extracting lithium salts in lithium-containing brine

The invention relates to a coordinate extracting system for extracting lithium from salt lake brine with extraction method, which comprises the following steps of (1) acidity of raw material liquid adjustment: adding hydrochloric acid to the salt lake brine to adjust the pH value of the raw material liquid to 1 to 5 so that the raw material liquid is obtained; (2) extracting lithium: carrying out three-stage extraction on the raw material liquid obtained in step (1) by using TBP-BA-FeCl3 solvent naphtha as an extracting agent to obtain an organic phase; (3) organic phase washing: carrying out three-stage washing to the organic phase obtained in the step (2) by using the hydrochloric acid as a washing agent; (4) organic phase reextraction: carrying out three-stage extraction on the organic phase obtained in the step (3) by using hydrochloric acid as a reextraction agent to obtain lithium chloride solution. The invention has the advantages of simple technique, easy control, low reextraction acidity, low requirements on reextraction equipment materials and concentration of lithium in the material brine, and no need of evaporation concentration of thin lithium solution, thereby saving energy, reducing consumption, decreasing the production cost, and simultaneously improving the total recovery rate of the lithium effectively.

Coordinate extracting system for extracting lithium from salt lake brine with extraction method

The invention provides a method for extracting lithium salt from lithium brine. The method comprises the following steps: extraction step: adding a co-extracting agent FeCl3 and an extraction agent tributyl phosphate (TBP) to lithium brine to extract lithium so as to obtain an organic phase LiFeCl4.2TBP and a water phase raffinate; reverse extraction step: adding a hydrochloric acid liquor to the organic phase LiFeCl4.2TBP for reverse extraction to obtain organic phase LiFeCl4.2TBP and water phase LiCl; and phase inversion step: inversing phase for the organic phase LiFeCl4.2TBP containing hydrogen ions by a liquor of alkali chloride, alkaline earth chloride or a mixture MCln (n is greater than or equal to 1) as a phase inversion agent to obtain an organic phase M(FeCl4)n.2TBP. According to the method for extracting lithium salt from lithium brine provided by the invention, the production cost of extracting lithium salt can be lowered.

Method for extracting lithium salt from lithium brine

The invention relates to a method for preenriching and separating lithium and boron from salt lake brine by liquid-liquid-liquid three-phase extraction, which comprises the following steps: adding water-soluble auxiliary extractant into a salt lake concentrated brine solution, regulating the pH value of the brine, adding water-soluble high molecular polymer, and thoroughly mixing at room temperature to obtain an upper/lower two-layer liquid-phase system; adding organic extractant, and mixing to obtain an upper/middle/lower three-layer liquid-phase system; and taking the upper and middle phases from the three-liquid-phase system, and respectively recovering lithium and boron in the upper and middle phases by back washing The invention can simultaneously enrich and extract lithium and boron by one-step extraction from high-magnesium/lithium-ratio salt lake brine, and can separate the lithium and boron from abundant coexistent ions of magnesium, calcium and other impurity metals in the brine The lithium and boron are respectively selectively enriched from the upper and middle phases in the three-liquid-phase system to implement primary separation, thereby facilitating the subsequent purification and refinement The three-liquid-phase extraction can be carried out under neutral or weakly-acidic conditions, and has strong adaptability

Method for preenriching and separating lithium and boron from salt lake brine by liquid-liquid-liquid three-phase extraction

The invention provides a method for preparing industrial lithium carbonate by using salt lake brine with a high magnesium-to-lithium ratio In the method, a TBP-CON-KS+FeCl3 is used as an extraction system to extract and back-extract impurity-free salt lake brine with a high magnesium-to-lithium ratio, the residual liquid obtained after back-extraction is converted by alkaline liquor for precipitation, the precipitate is washed to form an industrial lithium carbonate product and the lithium carbonate content is more than or equal to 990 percent and is in accordance with the requirements of GB/T 11 075-2003 standards The method has the advantages that: liquid-liquid extraction with an organic solvent is adopted to realize the separation of lithium from magnesium, the lithium carbonate is precipitated by inorganic slats, the lithium carbonate is extracted from the salt lake brine with a high magnesium-to-lithium ratio, the process is simple, the control is easy, the operational reliability is high and the application range is wide; a process of calcination and diluted lithium solution evaporation and concentration is saved, the energy consumption is only 30 to 50 percent of that of the conventional process for producing lithium carbonate by using lithium-containing brine; initial raw material consumption comparison show that the production cost of the method is only about 8 percent of that of the prior art; and the raw material brine can return to a storage pool after the extraction of the lithium carbonate, so no by production disposal problem is involved, environmental pollution is relatively low and lithium yield in the whole process is more than or equal to 70 percent

Method for preparing lithium carbonate by using salt lake brine with high magnesium-to-lithium ratio

The invention provides a method for preparing a potash magnesium sulphate fertilizer by utilizing potassium-bearing sulfate mineral, which takes the potassium-bearing sulfate mineral obtained by solarization of sulphate type salt lake potassium-containing brine water as a raw material to prepare potash magnesium sulphate fertilizer products in accordance with national potash magnesium sulphate fertilizer product standard, through processes such as crushing, grinding ore, decomposing and converting, floatation and separation, secondary pulp washing and so on. The method utilizes decomposing mother liquor and secondary pulp washing liquid to decompose raw material ores, the circulating utilization ratio of the decomposing mother liquor is more than or equal to 80 percent, and the circulating utilization ratio of the secondary pulp washing liquid reaches 100 percent, thereby improving yield of potassium, reducing water amount for decomposition and reducing the water consumption of ton-product by 30 to 70 percent compared with other methods for producing the potash magnesium sulphate fertilizer. The whole production process is carried out at normal temperature and pressure, which reduces energy consumption; and the quality of the potash magnesium sulphate fertilizer products meets or exceeds national standard (GB/T20937-2007) for potash magnesium sulphate fertilizer qualified products.

Process for preparing potash magnesium sulphate fertilizer with kalium containing sulfate

The present invention provides process of preparing potassium sulfate with potassium containing subtype magnesium sulfate bittern. The process includes naturally evaporating potassium containing subtype magnesium sulfate bittern from salt lake to crystallize and separate out potassium containing sulfate and sulfate radical containing carnallite successively; grinding the potassium containing sulfate, decomposing to convert and floating to obtain picromerite; decomposing sulfate radical containing carnallite to convert and floating to obtain coarse potassium chloride; mixing picromerite, coarse potassium chloride and potassium sulfate mother liquid to obtain slurry, washing, filtering, decomposing to convert and filtering separation to obtain potassium sulfate. The present invention has low production cost, high yield and high product quality.

Process of preparing potassium sulfate with potassium containing bittern of magnesium sulfate subtype

The invention provides a method for preparing high-grade potassium chloride from potassium-containing brine of a sulfate type salt lake. The method uses epsomite mixed mineral obtained by solarizing the potassium-containing brine of the sulfate type salt lake on a salt farm, sulfate-containing carnallite mixed mineral and saturated magnesium chloride brine as the raw material, from which sodium chloride and magnesium sulfate contained are removed by a salting-out technique with MgCl2 brine of certain concentration at the normal temperature; potassium-containing brine is obtained by leaching contained potassium and adjusting the composition of the brine; the high saturated potassium-containing brine is mixed into saturated MgCl2 brine for extraction of high-grade carnallite, which is decomposed to obtain the potassium chloride product. The obtained potassium chloride product has high grade and high yield (the KCl content is higher than or equal to 95 percent, and the K yield is higher than or equal to 60 percent).

Method for preparing potassium chloride by employing sulfate type salt lake potassium-containing brine

The invention provides a method for separating and extracting potassium chloride by utilizing potassium-containing solid ore. The method comprises the following steps: firstly, potassium-containing sulfurous mixed salt ore obtained by solar evaporation of potassium-containing sulfate saline brine in a brine pan, saturated magnesium chloride brine or unsaturated magnesium chloride brine which is diluted by rainwater, and water are mixed to be prepared into mixed ore, and the mixed ore is stirred and leached at medium and normal temperature and subjected to sodium removal and sulfur removal to obtain a potassium saturated liquid; secondly, the potassium saturated liquid is sent into the brine pan for evaporation until magnesium chloride is saturated, and subjected to liquid-solid separation to obtain low sodium magnesium sulfate and carnallite mixed ore; thirdly, the low sodium magnesium sulfate and the carnallite mixed ore are mixed with the saturated magnesium chloride brine, and subjected to liquid-solid separation to obtain low sodium carnallite; and fourthly, the low sodium carnallite is subjected to water decomposition and solid-liquid separation to obtain the potassium chloride. The product quality indicator (KCl) of the potassium chloride is more than or equal to 90 percent, and the yield of potassium is more than or equal to 60 percent. The method has the advantages that the method has simple technology, cheap and easily-obtained raw materials, low energy consumption and low cost, does not require any floatation agent during the preparation process, is environment-friendly, can treat various low-potassium and high-sulfur minerals, can realize whole year production, and is not limited by climate and meteorologic conditions.

Haimin Li

Papers

Method for preparing lithium carbonate by using salt lake brine with high magnesium-to-lithium ratio

Process for preparing potash magnesium sulphate fertilizer with kalium containing sulfate

Process of preparing potassium sulfate with potassium containing bittern of magnesium sulfate subtype

Method for preparing potassium chloride by employing sulfate type salt lake potassium-containing brine

Method for separating and extracting potassium chloride from potassium-containing solid mine