Comprehensive, efficient and high-purity extraction process for lithium, rubidium and cesium

Abstract

The invention relates to the technical field of extraction of lithium, rubidium and cesium, and discloses a comprehensive efficient high-purity extraction process of lithium, rubidium and cesium, lithium, rubidium and cesium are prepared from lithium precipitation mother liquor in a large scale by adopting a centrifugal solvent extraction method, and finally a lithium salt product with the lithium purity of 99.5% or above, a rubidium salt product with the rubidium purity of 80% or above and a rubidium salt product with the cesium purity of 92% or above are obtained. The concentration of Li in the raffinate can be reduced to below 5mg / l, the concentration of Li in the strip liquor can be more than 20g / l, the concentration of Cs in the strip liquor can be more than 18g / l, and the concentration of Rb in the strip liquor can be more than 18g / l. The whole process route is high in automation degree, large in yield, free of waste gas, waste residue and waste liquid discharge and good in system stability.

Description

Technical Field

[0001] The invention relates to the technical field of lithium rubidium cesium extraction, in particular to a lithium rubidium cesium comprehensive high-efficiency and high-purity extraction process. Background Art

[0002] The composition of rubidium-cesium lithium mica is relatively complex, mainly including rare alkali metals such as lithium, rubidium, cesium, niobium, and tantalum, and it has great economic value. Rubidium and cesium are mostly used in the synthesis of photocathode materials, and are also essential materials in the fields of infrared technology and atomic clocks. Researching effective separation and extraction technologies and developing more application fields will be the top priority for the future development of rubidium and cesium. Rubidium and cesium are also important materials for photoelectric conversion such as photocells, photoelectric emission tubes, television camera tubes, and photomultiplier tubes. They are irreplaceable in some high-tech industries and are essential materials for infrared technologies such as atomic clocks, laser technology, and radiation detection equipment. Due to its scarce and difficult-to-develop resource attributes, as the application of rubidium and cesium in perovskite and other high-tech fields is further expanded, the price of cesium is expected to increase significantly, and the industry will be in a continuous high prosperity cycle in the future. Rubidium and cesium have good conductivity, transparency, stability and light absorption properties. Due to its wide application in solar cells, the demand for rubidium and cesium is currently increasing year by year.

[0003] Lithium: At present, the main production methods of lithium carbonate are lithium extraction from ore, lithium extraction from salt lakes, and lithium extraction from secondary lithium resources. Among them, lithium extraction from lithium ore is the earliest and most mature process. Lithium extraction from ore mostly uses sulfuric acid or sulfate treatment process. After solution leaching, impurity removal and concentration, a high-lithium solution (Li: 20-30g·L -1 ), and then precipitate with sodium carbonate (soda ash) to obtain lithium carbonate products. Since lithium carbonate has a certain solubility, solid-liquid separation is performed in the later stage to obtain lithium precipitation mother liquor, which has a high concentration of Li+ (Li: 1.5-1.8g·L-1) and a large amount of Na + The complex salt system of lithium in the mother liquor makes it difficult to recover lithium. The battery industry has seen explosive growth in demand for basic lithium salts (lithium carbonate, lithium hydroxide and lithium chloride), especially lithium carbonate. As the basic raw material for lithium, lithium carbonate can be converted into a variety of other lithium compounds. However, the large amount of lithium precipitation mother liquor produced by the lithium carbonate production process still contains a high concentration of lithium, which will be wasted if discharged directly. Therefore, improving the recycling rate of lithium resources and the quality of recycled lithium salt products have become the key to maximizing the production benefits of new energy companies. Summary of the invention

[0004] 1. Technical issues to be resolved

[0005] In view of the deficiencies of the prior art, the present invention provides a comprehensive, efficient and high-purity extraction process for lithium, rubidium and cesium.

[0006] (II) Technical solution

[0007] A comprehensive high-efficiency and high-purity extraction process of lithium, rubidium and cesium comprises the following steps:

[0008] S1, lithium extraction line:

[0009] Pretreatment of lithium precipitation mother liquor: sodium hydroxide is added to the lithium precipitation mother liquor to adjust the pH to 11-13, stirred in a reactor for 10 minutes, filtered to remove suspended matter, and obtain lithium extraction pre-liquid;

[0010] Three-stage lithium extraction: lithium extractant and lithium pre-extraction liquid are mixed and stirred through a new type of ultra-gravity centrifugal extractor to make the two phases fully contact, Li is selectively extracted by the extractant, and the Li-loaded organic phase and the rubidium-cesium sodium lithium precipitation mother liquor are separated by centrifugal force. The raffinate is used as the cesium extraction stock solution, the organic phase lithium extractant is input from the light phase of the extractor, and the lithium pre-extraction liquid is input from the heavy phase of the extractor to perform three-stage countercurrent extraction, the O / A ratio is (3-5):1, the rotation speed is 40-45Hz, and the equilibrium pH is 6-6.5;

[0011] Three-stage washing: Load Li + A weak acid detergent is added to the oil phase to remove the sodium and potassium elements, and the washing water is returned to the stock solution for cyclic extraction. The lithium-loaded organic phase is input from the light phase of the extractor, and the acid is input from the heavy phase of the extractor to perform three-stage countercurrent washing. The O / A ratio is (12-13):1, the rotation speed is 40-45Hz, and the equilibrium pH is 5-5.5;

[0012] Three-stage stripping: hydrochloric acid or sulfuric acid stripping agent is used to carry out ion exchange with the oil phase loaded with Li+ under acidic conditions, and mixed separation is completed in a centrifuge to obtain a high-concentration lithium-rich solution and a blank organic phase. The blank organic phase is refluxed to the extractant, and the high-concentration lithium-rich solution can be further processed to produce battery-grade lithium salt products. The lithium-loaded organic phase is input from the light phase of the extractor, and the acid is input from the heavy phase of the extractor to perform three-stage countercurrent extraction. The O / A ratio is (12-13):1, the rotation speed is 40-45Hz, and the equilibrium pH is 4-4.5;

[0013] S2, cesium extraction line:

[0014] Pretreatment of cesium extraction solution: Add sodium hydroxide to the lithium raffinate to adjust the pH to 11-13 and stir in the reactor for 10 minutes;

[0015] Three-stage cesium extraction: The cesium extractant and the cesium pre-extraction solution are mixed and stirred by a new ultra-gravity centrifugal extractor to make the two phases fully contact. +The extractant is selectively extracted, and the Cs-loaded organic phase and the rubidium sodium lithium precipitation mother liquor are separated by centrifugal force. The raffinate is used as the rubidium extraction stock solution. The organic phase cesium extractant is input from the light phase of the extractor, and the cesium extraction pre-liquid is input from the heavy phase of the extractor to perform three-stage countercurrent extraction. The O / A ratio is (5-7): 1, the rotation speed is 40-45Hz, and the equilibrium pH is 5-5.5;

[0016] Secondary washing: Load Cs + A weak acid detergent is added to the oil phase to remove the sodium and potassium elements, and the washing water is returned to the original solution for cyclic extraction. The cesium-loaded organic phase is input from the light phase of the extractor, and the acid is input from the heavy phase of the extractor to perform a two-stage countercurrent extraction. The O / A ratio is (12-15): 1, the rotation speed is 40-45Hz, and the equilibrium pH is 4-4.5;

[0017] Secondary stripping: using hydrochloric acid or sulfuric acid stripping agent and loaded Cs + The oil phase undergoes ion exchange under acidic conditions, and mixed separation is completed in a centrifuge to obtain a high-concentration cesium-rich solution and a blank organic phase. The blank organic phase is refluxed to the extractant. The high-concentration cesium-rich solution can be further processed to produce photovoltaic material cesium salt products. The cesium-loaded organic phase is input from the light phase of the extractor, and the acid is input from the heavy phase of the extractor to perform secondary countercurrent extraction. The O / A ratio is (12-15): 1, the rotation speed is 40-45Hz, and the equilibrium pH is 2-3.5;

[0018] S3, Rubidium extraction wire:

[0019] Pretreatment of rubidium extraction stock solution: Add sodium hydroxide to the cesium extraction raffinate to adjust the pH to 11-13, and stir in the reactor for 10 minutes;

[0020] Three-stage rubidium extraction: The rubidium extractant and the rubidium extraction pre-liquid are mixed and stirred by a new ultra-gravity centrifugal extractor to make the two phases fully contact. + The extractant is selectively extracted, and the organic phase containing Rb load and the mother liquor containing sodium lithium precipitation are separated by stratification through centrifugal force. The raffinate is desalted and crystallized after oil removal, aeration, adsorption, and then evaporation and crystallization to form salt and water. The salt can be produced as alum, and the water is recycled. The organic phase rubidium extractant is input from the light phase of the extractor, and the rubidium extraction pre-liquid is input from the heavy phase of the extractor to perform three-stage countercurrent extraction. The O / A ratio is (5-7): 1, the rotation speed is 40-45Hz, and the equilibrium pH is 6-7;

[0021] Secondary washing: Load Rb + A weak acid detergent is added to the oil phase to wash away the sodium and potassium elements, and the washing water is returned to the original solution for cyclic extraction. The rubidium-loaded organic phase is input from the light phase of the extractor, and the acid solution is input from the heavy phase of the extractor to perform a two-stage countercurrent extraction. The O / A ratio is (12-15): 1, the rotation speed is 40-45Hz, and the equilibrium pH is 5-5.5;

[0022] Secondary stripping: using hydrochloric acid or sulfuric acid stripping agent and loaded Rb + The oil phase undergoes ion exchange under acidic conditions, and mixed separation is completed in a centrifuge to obtain a high-concentration rubidium-rich solution and a blank organic phase. The blank organic phase is refluxed to the extractant. The high-concentration rubidium-rich solution can be further processed to produce photovoltaic material rubidium salt products. The rubidium-loaded organic phase is input from the light phase of the extractor, and the acid is input from the heavy phase of the extractor to perform secondary countercurrent extraction. The O / A ratio is (12-15): 1, the rotation speed is 40-45Hz, and the equilibrium pH is 4-4.5.

[0023] Preferably, in the lithium precipitation mother solution pretreatment, the volume ratio of the lithium precipitation mother solution to sodium hydroxide is 10:(1-2);

[0024] The volume ratio of the lithium extraction pre-liquid to the lithium extraction treatment reagent is (3-5):1;

[0025] The treatment reagents for lithium extraction include alcohols and ketones, alkyl phosphines and phosphates, mixed ion extractants and crown ethers;

[0026] The volume ratio of the crown ether compound to the organic sulfonate compound is (1-1.25):4;

[0027] The crown ether compounds include 1-aza-18-crown-6-ether, 2-(hydroxymethyl)-15-crown-5-ether, 1,3-diisopropoxycalix-4-crown-6, 1,3-diisopropoxycalix[4]crown-6, benzo-15-crown-5, N,N'-di(methoxymethyl)diaza-15-crown-5, N-phenylaza-15-crown-5, 5,6,14,15-dibenzo-4,7,13,16-tetraoxa-1,10-diazacyclopentane At least one of octadecadiene, 5,6-benzo-4,7,13,16,21,24-hexaoxa-1,10-diazabicyclo[8.8.8]hexacos-5-ene, and 4,7,13,18-tetraoxa-1,10-diazabicyclo[8.5.5]eicosane, preferably 5,6-benzo-4,7,13,16,21,24-hexaoxa-1,10-diazabicyclo[8.8.8]hexacos-5-ene;

[0028] The organic sulfonate compound is an alkyl sulfonate, and the sulfonation degree of the alkyl sulfonate is 28-32 mol%;

[0029] The preparation method of the phenyl ether compound comprises: uniformly mixing polyphenyl ether and a chloroform solution of chlorosulfonic acid with a volume fraction of 12% at a solid-liquid ratio of 1:10 g / mL, heating to 15° C., reacting for 4.5 hours, filtering, washing, and drying to obtain the compound.

[0030] Preferably, in the lithium raffinate pretreatment, the volume ratio of the lithium raffinate to sodium hydroxide is 7:(1-2);

[0031] The volume ratio of the cesium extraction pre-liquid to the cesium extraction treatment reagent is (5-7):1;

[0032] In the cesium extraction treatment reagent, the volume ratio of the phenol compound to the organic sulfonate compound is (1-1.25):4;

[0033] The crown ether compounds include 1-aza-18-crown-6-ether, 2-(hydroxymethyl)-15-crown-5-ether, 1,3-diisopropoxycalix-4-crown-6, 1,3-diisopropoxycalix[4]crown-6, benzo-15-crown-5, N,N'-di(methoxymethyl)diaza-15-crown-5, N-phenylaza-15-crown-5, 5,6,14,15-dibenzo-4,7,13,16-tetraoxa-1,10-diazacyclopentane At least one of octadecadiene, 5,6-benzo-4,7,13,16,21,24-hexaoxa-1,10-diazabicyclo[8.8.8]hexacos-5-ene, and 4,7,13,18-tetraoxa-1,10-diazabicyclo[8.5.5]eicosane, preferably 5,6-benzo-4,7,13,16,21,24-hexaoxa-1,10-diazabicyclo[8.8.8]hexacos-5-ene;

[0034] The organic sulfonate compound is an alkyl sulfonate, and the sulfonation degree of the alkyl sulfonate is 28-32 mol%;

[0035] The preparation method of the phenyl ether compound comprises: uniformly mixing polyphenyl ether and a chloroform solution of chlorosulfonic acid with a volume fraction of 12% at a solid-liquid ratio of 1:10 g / mL, heating to 15° C., reacting for 4.5 hours, filtering, washing, and drying to obtain the compound.

[0036] Preferably, in the cesium raffinate pretreatment, the volume ratio of the cesium raffinate to sodium hydroxide is 8:(1-2);

[0037] The volume ratio of the rubidium extraction pre-liquid to the rubidium extraction treatment reagent is (5-7):1;

[0038] In the rubidium extraction treatment reagent, the volume ratio of the crown ether compound to the organic sulfonate compound is (1-1.25):4;

[0039] Crown ether compounds include 1-aza-18-crown-6-ether, 2-(hydroxymethyl)-15-crown-5-ether, 1,3-diisopropoxycalix-4-crown-6, 1,3-diisopropoxycalix[4]crown-6, benzo-15-crown-5, N,N'-di(methoxymethyl)diaza-15-crown-5, N-phenylaza-15-crown-5, 5,6,14,15-dibenzo-4,7,13,16-tetraoxa-1,10-diazacyclodecane At least one of octa-5,14-diene, 5,6-benzo-4,7,13,16,21,24-hexaoxa-1,10-diazabicyclo[8.8.8]hexacos-5-ene, and 4,7,13,18-tetraoxa-1,10-diazabicyclo[8.5.5]eicosane, preferably 5,6-benzo-4,7,13,16,21,24-hexaoxa-1,10-diazabicyclo[8.8.8]hexacos-5-ene;

[0040] The organic sulfonate compound is an alkyl sulfonate, and its sulfonation degree is 28-32 mol%;

[0041] The preparation method of the phenyl ether compound is as follows: polyphenyl ether and a chloroform solution of chlorosulfonic acid with a volume fraction of 12% are uniformly mixed at a solid-liquid ratio of 1:10 g / mL, the mixture is heated to 15° C., reacted for 4.5 hours, filtered, washed, and dried to obtain the compound.

[0042] Preferably, the operation time of extraction, washing and stripping is 5-10 min, and the operation temperature is 25-30°C;

[0043] The treatment reagent used for washing and stripping is hydrochloric acid or sulfuric acid, preferably sulfuric acid;

[0044] The volume ratio of the lithium-loaded organic phase to the washing treatment reagent is (12-13):1, and the volume ratio of the lithium-loaded organic phase to the stripping treatment reagent is (12-13):1;

[0045] The volume ratio of the cesium-loaded organic phase to the washing treatment reagent is (12-15):1, and the volume ratio of the cesium-loaded organic phase to the stripping treatment reagent is (12-15):1;

[0046] The volume ratio of the rubidium-loaded organic phase to the washing treatment reagent is (12-15):1, and the volume ratio of the rubidium-loaded organic phase to the stripping treatment reagent is (12-15):1.

[0047] Preferably, in the lithium extraction step, the alcohol and ketone extractants selected include but are not limited to 2-octanol and methyl isobutyl ketone.

[0048] Preferably, in the cesium extraction step, the alkylphosphine and phosphate extractants selected include but are not limited to tributyl phosphate.

[0049] Preferably, in the rubidium extraction step, the mixed ion extractant selected includes but is not limited to a mixture of N263 (trioctylmethylammonium chloride) and P204 (di(2-ethylhexyl)phosphoric acid).

[0050] (III) Beneficial technical effects

[0051] 1. Use centrifugal solvent extraction method to prepare lithium rubidium and cesium on a large scale from lithium precipitation mother liquor, and finally obtain lithium salt products with lithium purity of more than 99.5%. Rubidium salt products with rubidium purity of more than 80%, cesium salt products with cesium purity of more than 92%. The whole process route has a high degree of automation, large output, no waste gas, waste residue, waste liquid discharge, and good system stability.

[0052] 2. Use multiple independently developed centrifugal extractors in series to form a multi-stage countercurrent extraction, washing, stripping and regeneration unit to meet large-flow production while reducing the number of series stages.

[0053] 3. The stock solution contains 2.5 g / L of Li, three-stage extraction (O / A=3-5:1), three-stage washing (O / A=12-15:1), acidity is about 0.5-0.6M, three-stage stripping (O / A=12-15:1), acidity is about 4-5M; under the above process parameters, the Li in the raffinate can be reduced to below 5 mg / l, and the Li in the stripping solution can reach more than 20 g / l.

[0054] 4. The original solution contains 0.23 g / L of Cs, the acidity of the three-stage extraction (O / A=5-7:1), the two-stage washing (O / A=12-13:1) is 1-2M, and the acidity of the two-stage stripping (O / A=12-13:1) is about 4-5M; under the above process parameters, the Cs in the stripping solution can reach more than 18 g / l.

[0055] 5. The original solution contains 1.58 g / L of Rb, three-stage extraction (O / A=5-7:1), two-stage washing (O / A=12-13:1), and two-stage enrichment stripping (O / A=12-13:1); under the above process parameters, the Rb in the stripping solution can reach more than 18 g / l. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] Figure 1 This is a process diagram for the extraction of lithium, rubidium and cesium.

[0057] Figure 2 This is the real-time result diagram of Li detection atomic absorption.

[0058] Figure 3 This is the real-time result diagram of Cs detection atomic absorption.

[0059] Figure 4 This is the real-time result diagram of Rb detection atomic absorption.

[0060] Figure 5 This is the ICP curve result diagram for K and Na detection. DETAILED DESCRIPTION

[0061] Example 1

[0062] (1) Lithium extraction line:

[0063] Pretreatment of lithium precipitation mother liquor: add sodium hydroxide to the lithium precipitation mother liquor at a volume ratio of 10:1, adjust the pH to 11, stir in a reactor for 10 minutes, filter to remove suspended matter, and obtain lithium extraction pre-liquid.

[0064] Lithium extraction (three-stage): The lithium extractant (oil phase) and the lithium extraction pre-liquid (aqueous phase) with a volume ratio of 3:1 are mixed and stirred through a new type of ultra-gravity centrifugal extractor to make the two phases fully contact. Li is selectively extracted by the extractant for 5 minutes. The Li-loaded organic phase (oil phase) and the mother liquor (aqueous phase) containing rubidium and cesium sodium lithium precipitation are separated by centrifugal force. The raffinate is used as the cesium extraction stock solution. The organic phase lithium extractant is input from the light phase of the extractor, and the lithium extraction pre-liquid is input from the heavy phase of the extractor. Three-stage countercurrent extraction is performed, the O / A ratio is 3:1, the rotation speed is 40Hz, and the equilibrium pH is 6.

[0065] Washing (three-stage): Li loading with a volume ratio of 12:1 + Weak acid detergent is added to the oil phase to remove sodium and potassium elements, and the washing water is returned to the original solution for cyclic extraction. The lithium-loaded organic phase is input from the light phase of the extractor, and the acid is input from the heavy phase of the extractor. A three-stage countercurrent washing is performed for 10 minutes, with an O / A ratio of 13:1, a rotation speed of 45 Hz, and an equilibrium pH of 5.5.

[0066] Stripping (three-stage): The hydrochloric acid stripping agent with a volume ratio of 1:12 undergoes ion exchange with the oil phase loaded with Li+ under acidic conditions, and the mixed separation is completed in the centrifuge to obtain a high-concentration lithium-rich solution and a blank organic phase. The blank organic phase is refluxed to the extractant, and the high-concentration lithium-rich solution can be further processed to produce battery-grade lithium salt products. The lithium-loaded organic phase is input from the light phase of the extractor, and the acid is input from the heavy phase of the extractor. The three-stage countercurrent extraction is performed for 5 minutes, the O / A ratio is 12:1, the rotation speed is 45Hz, and the equilibrium pH is 4.

[0067] The lithium extraction treatment reagents include alcohols and ketones, alkyl phosphines and phosphates, mixed ion extractants and crown ethers.

[0068] The volume ratio of the crown ether compound to the organic sulfonate compound is 1:4.

[0069] The crown ether compound is 5,6-benzo-4,7,13,16,21,24-hexaoxa-1,10-diazabicyclo[8.8.8]hexacos-5-ene.

[0070] The organic sulfonate compound is an alkyl sulfonate, and the sulfonation degree of the alkyl sulfonate is 28 mol%;

[0071] The preparation method of the phenyl ether compound comprises: uniformly mixing polyphenyl ether and a chloroform solution of chlorosulfonic acid with a volume fraction of 12% at a solid-liquid ratio of 1:10 g / mL, heating to 15° C., reacting for 4.5 hours, filtering, washing, and drying to obtain the compound.

[0072] (2) Cesium extraction line:

[0073] Pretreatment of cesium extraction solution: Add sodium hydroxide to the lithium raffinate at a volume ratio of 7:1, adjust the pH to 13, and stir in a reactor for 10 minutes.

[0074] Cesium extraction (third stage): The cesium extractant (oil phase) and the cesium pre-extraction solution (water phase) with a volume ratio of 5:1 are mixed and stirred by a new ultra-gravity centrifugal extractor to make the two phases fully contact. + The extractant was selectively extracted for 10 minutes, and the Cs-loaded organic phase (oil phase) and the rubidium sodium lithium precipitation mother liquor (aqueous phase) were separated by centrifugal force. The raffinate was used as the rubidium extraction stock solution. The organic phase cesium extractant was input from the light phase of the extractor, and the cesium extraction pre-liquid was input from the heavy phase of the extractor to perform three-stage countercurrent extraction. The O / A ratio was 7:1, the rotation speed was 45 Hz, and the equilibrium pH was 5.

[0075] Washing (secondary): Load Cs at a volume ratio of 15:1 + Weak acid detergent is added to the oil phase to remove sodium and potassium elements, and the washing water is returned to the original solution for cyclic extraction. The cesium-loaded organic phase is input from the light phase of the extractor, and the acid is input from the heavy phase of the extractor. A two-stage countercurrent extraction is performed for 5 minutes, with an O / A ratio of 12:1, a rotation speed of 40 Hz, and an equilibrium pH of 4.

[0076] Stripping (secondary): hydrochloric acid stripping agent and loaded Cs in a volume ratio of 1:15 + The oil phase undergoes ion exchange under acidic conditions, and mixed separation is completed in the centrifuge to obtain a high-concentration cesium-rich solution and a blank organic phase. The blank organic phase is refluxed to the extractant. The high-concentration cesium-rich solution can be further processed to produce photovoltaic material cesium salt products. The cesium-loaded organic phase is input from the light phase of the extractor, and the acid is input from the heavy phase of the extractor. The secondary countercurrent extraction is performed for 10 minutes, the O / A ratio is 15:1, the rotation speed is 40Hz, and the equilibrium pH is 2.

[0077] In the cesium extraction treatment reagent, the volume ratio of phenol compounds to organic sulfonate compounds is 1:4.

[0078] The crown ether compound is 5,6-benzo-4,7,13,16,21,24-hexaoxa-1,10-diazabicyclo[8.8.8]hexacos-5-ene.

[0079] The organic sulfonate compound is an alkyl sulfonate, and the sulfonation degree of the alkyl sulfonate is 32 mol%;

[0080] The preparation method of the phenyl ether compound comprises: uniformly mixing polyphenyl ether and a chloroform solution of chlorosulfonic acid with a volume fraction of 12% at a solid-liquid ratio of 1:10 g / mL, heating to 15° C., reacting for 4.5 hours, filtering, washing, and drying to obtain the compound.

[0081] (3) Rubidium wire:

[0082] Pretreatment of rubidium extraction stock solution: Add sodium hydroxide to the cesium extraction solution at a volume ratio of 8:1, adjust the pH to 13, and stir in a reactor for 10 minutes.

[0083] Rubidium extraction (three-stage): The rubidium extractant (oil phase) and the rubidium extraction pre-liquid (water phase) with a volume ratio of 5:1 are mixed and stirred by a new ultra-gravity centrifugal extractor to make the two phases fully contact. + The extractant is selectively extracted for 10 minutes, and the Rb-loaded organic phase (oil phase) and the sodium-containing lithium precipitation mother liquor (aqueous phase) are separated by centrifugal force. The raffinate is desalted and crystallized after oil removal, aeration, and adsorption to form salt and water. The salt can be produced as alum and the water is recycled. The organic phase rubidium extractant is input from the light phase of the extractor, and the rubidium extraction pre-liquid is input from the heavy phase of the extractor to perform three-stage countercurrent extraction. The O / A ratio is 5:1, the rotation speed is 45 Hz, and the equilibrium pH is 6.

[0084] Washing (secondary): Load Rb with a volume ratio of 12:1 + Weak acid detergent is added to the oil phase to remove sodium and potassium elements, and the washing water is returned to the original solution for cyclic extraction for 5 minutes. The rubidium-loaded organic phase is input from the light phase of the extractor, and the acid is input from the heavy phase of the extractor to perform secondary countercurrent extraction. The O / A ratio is 12:1, the rotation speed is 45 Hz, and the equilibrium pH is 5.5.

[0085] Stripping (secondary): hydrochloric acid stripping agent and loaded Rb in a volume ratio of 1:12 + The oil phase undergoes ion exchange under acidic conditions, and mixed separation is completed in the centrifuge to obtain a high-concentration rubidium-rich solution and a blank organic phase. The blank organic phase is refluxed to the extractant. The high-concentration rubidium-rich solution can be further processed to produce photovoltaic material rubidium salt products. The rubidium-loaded organic phase is input from the light phase of the extractor, and the acid is input from the heavy phase of the extractor. A two-stage countercurrent extraction is performed for 5 minutes, the O / A ratio is 15:1, the rotation speed is 40Hz, and the equilibrium pH is 4.

[0086] In the rubidium extraction treatment reagent, the volume ratio of the crown ether compound to the organic sulfonate compound is 1:4.

[0087] The crown ether compound is 5,6-benzo-4,7,13,16,21,24-hexaoxa-1,10-diazabicyclo[8.8.8]hexacos-5-ene.

[0088] The organic sulfonate compound is an alkyl sulfonate, and its sulfonation degree is 28 mol%;

[0089] The preparation method of the phenyl ether compound is as follows: polyphenyl ether and a chloroform solution of chlorosulfonic acid with a volume fraction of 12% are uniformly mixed at a solid-liquid ratio of 1:10 g / mL, the mixture is heated to 15° C., reacted for 4.5 hours, filtered, washed, and dried to obtain the compound.

[0090] Comparative Example 1: Example 1 in patent CN113174480B.

[0091] Table 1

[0092]

[0093] It can be seen from Table 1 that the leaching concentrations of lithium, rubidium and cesium extracted in Example 1 are higher than those in Comparative Example 1.

[0094] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A comprehensive, efficient and high-purity extraction process for lithium, rubidium and cesium, characterized in that: The following steps are involved: S1, lithium extraction line: Pretreatment of lithium precipitation mother liquor: sodium hydroxide is added to the lithium precipitation mother liquor to adjust the pH to 11-13, stirred in a reactor for 10 minutes, filtered to remove suspended matter, and obtain lithium extraction pre-liquid; Three-stage lithium extraction: lithium extractant and lithium pre-extraction liquid are mixed and stirred through a new type of ultra-gravity centrifugal extractor to make the two phases fully contact, Li is selectively extracted by the extractant, and the Li-loaded organic phase and the rubidium-cesium sodium lithium precipitation mother liquor are separated by centrifugal force. The raffinate is used as the cesium extraction stock solution, the organic phase lithium extractant is input from the light phase of the extractor, and the lithium pre-extraction liquid is input from the heavy phase of the extractor to perform three-stage countercurrent extraction, the O / A ratio is (3-5):1, the rotation speed is 40-45Hz, and the equilibrium pH is 6-6.5; Three-stage washing: Load Li + A weak acid detergent is added to the oil phase to remove the sodium and potassium elements, and the washing water is returned to the stock solution for cyclic extraction. The lithium-loaded organic phase is input from the light phase of the extractor, and the acid is input from the heavy phase of the extractor to perform three-stage countercurrent washing. The volume ratio of the oil-water phase O / A is (12-13):1, the rotation speed is 40-45Hz, and the equilibrium pH is 5-5.5; Three-stage stripping: hydrochloric acid or sulfuric acid stripping agent is used to carry out ion exchange with the oil phase loaded with Li+ under acidic conditions, and mixed separation is completed in a centrifuge to obtain a high-concentration lithium-rich solution and a blank organic phase. The blank organic phase is refluxed to the extractant, and the high-concentration lithium-rich solution can be further processed to produce battery-grade lithium salt products. The lithium-loaded organic phase is input from the light phase of the extractor, and the acid is input from the heavy phase of the extractor to perform three-stage countercurrent extraction. The O / A ratio is (12-13):1, the rotation speed is 40-45Hz, and the equilibrium pH is 4-4.5; S2, cesium extraction line: Pretreatment of cesium extraction solution: Add sodium hydroxide to the lithium raffinate to adjust the pH to 11-13 and stir in the reactor for 10 minutes; Three-stage cesium extraction: The cesium extractant and the cesium pre-extraction solution are mixed and stirred by a new ultra-gravity centrifugal extractor to make the two phases fully contact. + The extractant is selectively extracted, and the Cs-loaded organic phase and the rubidium sodium lithium precipitation mother liquor are separated by centrifugal force. The raffinate is used as the rubidium extraction stock solution. The organic phase cesium extractant is input from the light phase of the extractor, and the cesium extraction pre-liquid is input from the heavy phase of the extractor to perform three-stage countercurrent extraction. The O / A ratio is (5-7): 1, the rotation speed is 40-45Hz, and the equilibrium pH is 5-5.5; Secondary washing: Load Cs + A weak acid detergent is added to the oil phase to wash away the sodium and potassium elements, and the washing water is returned to the original solution for cyclic extraction. The cesium-loaded organic phase is input from the light phase of the extractor, and the acid solution is input from the heavy phase of the extractor to perform a two-stage countercurrent extraction. The O / A ratio is (12-15): 1, the rotation speed is 40-45Hz, and the equilibrium pH is 4-4.5; Secondary stripping: using hydrochloric acid or sulfuric acid stripping agent and loaded Cs + The oil phase undergoes ion exchange under acidic conditions, and mixed separation is completed in a centrifuge to obtain a high-concentration cesium-rich solution and a blank organic phase. The blank organic phase is refluxed to the extractant. The high-concentration cesium-rich solution can be further processed to produce photovoltaic material cesium salt products. The cesium-loaded organic phase is input from the light phase of the extractor, and the acid is input from the heavy phase of the extractor to perform secondary countercurrent extraction. The O / A ratio is (12-15): 1, the rotation speed is 40-45Hz, and the equilibrium pH is 2-3.5; S3, Rubidium extraction wire: Pretreatment of rubidium extraction stock solution: Add sodium hydroxide to the cesium extraction raffinate to adjust the pH to 11-13, and stir in the reactor for 10 minutes; Three-stage rubidium extraction: The rubidium extractant and the rubidium extraction pre-liquid are mixed and stirred by a new ultra-gravity centrifugal extractor to make the two phases fully contact. + The extractant is selectively extracted, and the organic phase containing Rb load and the mother liquor containing sodium lithium precipitation are separated by centrifugal force. The raffinate is desalted and crystallized after oil removal, aeration, adsorption, and then evaporation and crystallization to form salt and water. The salt can be produced as alum, and the water is recycled. The organic phase rubidium extractant is input from the light phase of the extractor, and the rubidium extraction pre-liquid is input from the heavy phase of the extractor to perform three-stage countercurrent extraction. The O / A ratio is (5-7): 1, the rotation speed is 40-45Hz, and the equilibrium pH is 6-7; Secondary washing: Load Rb + A weak acid detergent is added to the oil phase to wash away the sodium and potassium elements, and the washing water is returned to the original solution for cyclic extraction. The rubidium-loaded organic phase is input from the light phase of the extractor, and the acid solution is input from the heavy phase of the extractor to perform a two-stage countercurrent extraction. The O / A ratio is (12-15): 1, the rotation speed is 40-45Hz, and the equilibrium pH is 5-5.5; Secondary stripping: using hydrochloric acid or sulfuric acid stripping agent and loaded Rb + The oil phase undergoes ion exchange under acidic conditions, and mixed separation is completed in a centrifuge to obtain a high-concentration rubidium-rich solution and a blank organic phase. The blank organic phase is refluxed to the extractant. The high-concentration rubidium-rich solution can be further processed to produce photovoltaic material rubidium salt products. The rubidium-loaded organic phase is input from the light phase of the extractor, and the acid is input from the heavy phase of the extractor to perform secondary countercurrent extraction. The O / A ratio is (12-15): 1, the rotation speed is 40-45Hz, and the equilibrium pH is 4-4.

5.

2. A lithium, rubidium, and cesium comprehensive, efficient, and high-purity extraction process according to claim 1, characterized in that: In the lithium precipitation mother solution pretreatment, the volume ratio of the lithium precipitation mother solution to sodium hydroxide is 10:(1-2); The volume ratio of the lithium extraction pre-liquid to the lithium extraction treatment reagent is (3-5):1; The treatment reagents for lithium extraction include alcohols and ketones, alkyl phosphines and phosphates, mixed ion extractants and crown ethers; The volume ratio of the crown ether compound to the organic sulfonate compound is (1-1.25):4; The crown ether compounds include 1-aza-18-crown-6-ether, 2-(hydroxymethyl)-15-crown-5-ether, 1,3-diisopropoxycalix-4-crown-6, 1,3-diisopropoxycalix[4]crown-6, benzo-15-crown-5, N,N'-di(methoxymethyl)diaza-15-crown-5, N-phenylaza-15-crown-5, 5,6,14,15-dibenzo-4,7,13,16-tetraoxa-1,10-diazacyclopentane At least one of octadecadiene, 5,6-benzo-4,7,13,16,21,24-hexaoxa-1,10-diazabicyclo[8.8.8]hexacos-5-ene, and 4,7,13,18-tetraoxa-1,10-diazabicyclo[8.5.5]eicosane, preferably 5,6-benzo-4,7,13,16,21,24-hexaoxa-1,10-diazabicyclo[8.8.8]hexacos-5-ene; The organic sulfonate compound is an alkyl sulfonate, and the sulfonation degree of the alkyl sulfonate is 28-32 mol%; The preparation method of the phenyl ether compound comprises: uniformly mixing polyphenyl ether and a chloroform solution of chlorosulfonic acid with a volume fraction of 12% at a solid-liquid ratio of 1:10 g / mL, heating to 15° C., reacting for 4.5 hours, filtering, washing, and drying to obtain the compound.

3. A comprehensive high-efficiency and high-purity extraction process of lithium, rubidium and cesium according to claim 1, characterized in that: In the lithium raffinate pretreatment, the volume ratio of the lithium raffinate to sodium hydroxide is 7:(1-2); The volume ratio of the cesium extraction pre-liquid to the cesium extraction treatment reagent is (5-7):1; In the cesium extraction treatment reagent, the volume ratio of the phenol compound to the organic sulfonate compound is (1-1.25):4; The crown ether compounds include 1-aza-18-crown-6-ether, 2-(hydroxymethyl)-15-crown-5-ether, 1,3-diisopropoxycalix-4-crown-6, 1,3-diisopropoxycalix[4]crown-6, benzo-15-crown-5, N,N'-di(methoxymethyl)diaza-15-crown-5, N-phenylaza-15-crown-5, 5,6,14,15-dibenzo-4,7,13,16-tetraoxa-1,10-diazacyclopentane At least one of octadecadiene, 5,6-benzo-4,7,13,16,21,24-hexaoxa-1,10-diazabicyclo[8.8.8]hexacos-5-ene, and 4,7,13,18-tetraoxa-1,10-diazabicyclo[8.5.5]eicosane, preferably 5,6-benzo-4,7,13,16,21,24-hexaoxa-1,10-diazabicyclo[8.8.8]hexacos-5-ene; The organic sulfonate compound is an alkyl sulfonate, and the sulfonation degree of the alkyl sulfonate is 28-32 mol%; The preparation method of the phenyl ether compound comprises: uniformly mixing polyphenyl ether and a chloroform solution of chlorosulfonic acid with a volume fraction of 12% at a solid-liquid ratio of 1:10 g / mL, heating to 15° C., reacting for 4.5 hours, filtering, washing, and drying to obtain the compound.

4. A comprehensive high-efficiency and high-purity extraction process of lithium, rubidium and cesium according to claim 1, characterized in that: In the cesium raffinate pretreatment, the volume ratio of the cesium raffinate to sodium hydroxide is 8:(1-2); The volume ratio of the rubidium extraction pre-liquid to the rubidium extraction treatment reagent is (5-7):1; In the rubidium extraction treatment reagent, the volume ratio of the crown ether compound to the organic sulfonate compound is (1-1.25):4; Crown ether compounds include 1-aza-18-crown-6-ether, 2-(hydroxymethyl)-15-crown-5-ether, 1,3-diisopropoxycalix-4-crown-6, 1,3-diisopropoxycalix[4]crown-6, benzo-15-crown-5, N,N'-di(methoxymethyl)diaza-15-crown-5, N-phenylaza-15-crown-5, 5,6,14,15-dibenzo-4,7,13,16-tetraoxa-1,10-diazacyclodecane At least one of octa-5,14-diene, 5,6-benzo-4,7,13,16,21,24-hexaoxa-1,10-diazabicyclo[8.8.8]hexacos-5-ene, and 4,7,13,18-tetraoxa-1,10-diazabicyclo[8.5.5]eicosane, preferably 5,6-benzo-4,7,13,16,21,24-hexaoxa-1,10-diazabicyclo[8.8.8]hexacos-5-ene; The organic sulfonate compound is an alkyl sulfonate, and its sulfonation degree is 28-32 mol%; The preparation method of the phenyl ether compound is as follows: polyphenyl ether and a chloroform solution of chlorosulfonic acid with a volume fraction of 12% are uniformly mixed at a solid-liquid ratio of 1:10 g / mL, the mixture is heated to 15° C., reacted for 4.5 hours, filtered, washed, and dried to obtain the compound.

5. A comprehensive high-efficiency and high-purity extraction process of lithium, rubidium and cesium according to any one of claims 1 to 4, characterized in that: The operation time of extraction, washing and stripping is 5-10min, and the operation temperature is 25-30℃; The treatment reagent used for washing and stripping is hydrochloric acid or sulfuric acid, preferably sulfuric acid; The volume ratio of the lithium-loaded organic phase to the washing treatment reagent is (12-13):1, and the volume ratio of the lithium-loaded organic phase to the stripping treatment reagent is (12-13):1; The volume ratio of the cesium-loaded organic phase to the washing treatment reagent is (12-15):1, and the volume ratio of the cesium-loaded organic phase to the stripping treatment reagent is (12-15):1; The volume ratio of the rubidium-loaded organic phase to the washing treatment reagent is (12-15):1, and the volume ratio of the rubidium-loaded organic phase to the stripping treatment reagent is (12-15):

1.

6. A comprehensive high-efficiency and high-purity extraction process of lithium, rubidium and cesium according to any one of claims 1 to 5, characterized in that: In the lithium extraction step, the alcohol and ketone extractants selected include but are not limited to 2-octanol and methyl isobutyl ketone.

7. A comprehensive high-efficiency and high-purity extraction process of lithium, rubidium and cesium according to any one of claims 1 to 6, characterized in that: In the cesium extraction step, the alkylphosphine and phosphate extractants selected include but are not limited to tributyl phosphate.

8. A comprehensive high-efficiency and high-purity extraction process of lithium, rubidium and cesium according to any one of claims 1 to 7, characterized in that: In the rubidium extraction step, the mixed ion extractants selected include but are not limited to a mixture of N263 (trioctylmethylammonium chloride) and P204 (di(2-ethylhexyl)phosphoric acid).

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