Method for extracting cesium salt and rubidium salt from ore washing waste brine

Abstract

The invention relates to the technical field of separation and purification, and discloses a method for extracting cesium salt and rubidium salt from ore washing waste brine, which comprises the following steps: filtering the ore washing waste brine containing rubidium and cesium to remove impurities, adding alkali to adjust the pH value to be more than 12, simultaneously adding a settling agent, precipitating calcium, magnesium, lead, zinc and copper metal ions in the feed liquid, adjusting the pH value of the filtrate to be neutral, and filtering to obtain the cesium salt and rubidium salt. Concentrating 99% of rubidium and cesium into crystallization mother liquor while concentrating and crystallizing to recover potassium chloride and sodium chloride; after the alkalinity of the crystallization mother liquor is adjusted, the crystallization mother liquor serves as feed liquid, a t-BAMBP-benzene and hydrogenated petroleum kerosene extraction system is adopted, multi-stage counter-current extraction-washing-reverse extraction treatment is conducted, and reverse extraction liquor containing cesium salt and raffinate are obtained; and extracting rubidium by taking raffinate as feed liquid for extracting rubidium and lithium to obtain high-quality rubidium salt and cesium salt products. According to the method, high-quality rubidium salt and cesium salt are prepared, the cost is saved, the operation conditions are improved, and the environmental pollution is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of separation and purification, and in particular to a method for extracting cesium salt and rubidium salt from waste brine from ore washing. Background Art

[0002] Cesium and rubidium are important scarce alkali metal resources and are widely used in industrial catalysis, medicine, special glass and other fields. The existing methods for separating cesium and rubidium mostly use distributed precipitation, fractional crystallization, ion exchange and solvent extraction. In order to obtain high-quality cesium and rubidium, solvent extraction is often used.

[0003] The existing methods for extracting cesium salts and rubidium salts from waste brine from ore washing have the following problems: when precipitating and removing metal ions such as calcium, magnesium, lead, zinc, and copper, magnesium hydroxide is not easy to precipitate, resulting in incomplete removal of magnesium, which not only affects the purity of the subsequent extraction of cesium salts and rubidium salts, but also reduces the recovery rate of cesium and rubidium, resulting in waste of cesium and rubidium; and the existing methods for extracting cesium salts and rubidium salts do not change the content of other substances in the feed solution and avoid adding other substances as much as possible while ensuring the separation and recovery of cesium or rubidium from other alkali metals and impurity ions. The existing methods for extracting cesium salts and rubidium salts are easy to introduce other substances, resulting in obstacles to the subsequent recovery and use of the feed solution, and increasing the recovery cost.

[0004] Chinese patent CN112239221A discloses a method for extracting rubidium chloride from high-salt brine containing rubidium. In order to improve the separation effect of rubidium, SnCl4 is used to first precipitate rubidium from the system, and then it is dried, calcined and de-oiled, and the carbon deposits generated during the calcination process are removed by a recrystallization method to extract high-purity rubidium chloride. However, this method introduces SnCl4 with higher value for precipitation and de-oiling, and introduces tin into the system, which increases the cost and brings inconvenience to the operation. For example, a fully enclosed drying and calcining equipment must be used to recover Sn and SnCl4 during calcination. The drying system of 110°C is very difficult to control. If you are not careful, SnCl4 with a boiling point of 114°C will volatilize, especially the carbon or CO generated in the middle of the calcination process will cause SnCl4 to be reduced, and the low-melting-point tin will melt on the surface of the rubidium salt and cannot be removed, greatly reducing the purity of the product. During the calcination process, the volatilization and oxidation of SnCl4 bring many problems to the equipment and operating conditions. In engineering practice, tin oxide can cause pipe wall blockage, SnCl4 leakage and other problems, which increase production costs and prevent continuous production. The tin compounds leaked during the process can cause serious irreversible damage to operators. In addition, this method is only suitable for the preparation of rubidium chloride salts, not for the preparation of other salts such as rubidium sulfate and rubidium carbonate. This patented extraction system only uses sulfonated kerosene as a diluent. Due to the active SO3H -The groups are easy to precipitate with trace amounts of calcium and heavy metals in the solution, causing the extraction system to produce three phases and the extraction system cannot operate normally. Summary of the invention

[0005] In view of this, the object of the present invention is to provide a process for extracting cesium salt and rubidium salt from waste brine from ore washing, so as to solve the problems pointed out in the above background technology.

[0006] In order to achieve the above-mentioned invention object, the technical solution adopted is as follows:

[0007] A process for extracting cesium salt and rubidium salt from waste brine from ore washing, comprising the following steps:

[0008] S1. First, the solid impurities are filtered out of the ore-washing waste brine containing rubidium and cesium, and the pH value is adjusted to above 12 with an alkaline agent. At the same time, a carbon source is introduced to precipitate the metal ions of calcium, magnesium, lead, zinc and copper as hydroxides, and produce large particles of carbonate, thereby solving the problem that magnesium hydroxide is not easy to precipitate and filter, ensuring that the metal ion content is below 10 ppm, and obtaining a feed liquid that can be evaporated;

[0009] S2, the feed liquid obtained in S1 is further concentrated and crystallized to produce potassium chloride and sodium chloride crystals, and by controlling the crystallization sequence and crystallization point, 99% of rubidium and cesium enter the evaporation mother liquor;

[0010] S3, the OH of the extract solution treated in step S2 - The concentration is adjusted to within the range of 0.25-1.0 mol / l, and a box-type extraction tank is used for cascade countercurrent extraction-washing-stripping treatment to obtain a stripping solution and a raffinate containing a cesium salt; in this step, different acids are selected for stripping according to the product scheme to obtain different cesium salts;

[0011] S4, the raffinate OH from step S3 cesium extraction - The concentration is adjusted to a range of 1.1-1.8 mol / l, and a box-type extraction tank is used for cascade countercurrent extraction-washing-stripping treatment to obtain a stripping solution and a raffinate containing a rubidium salt; in this step, different acids are selected for stripping according to the product scheme to obtain different rubidium salts;

[0012] S5, removing oil from the weakly acidic stripping solution treated in steps S3 and S4, and performing reduced pressure evaporation and crystallization to obtain slightly variegated cesium salt crystals and rubidium salt crystals;

[0013] S6. The cesium salt crystals and rubidium salt crystals obtained in step S5 are respectively redissolved to obtain nearly saturated cesium salt solutions and rubidium salt solutions, and then extracted with 1-3 levels, washed with 1-2 levels, and then stripped to obtain higher purity cesium salt solutions and rubidium salt solutions. After deep oil removal, the crystals are evaporated under reduced pressure to obtain pure high-purity cesium salts and rubidium salts.

[0014] As a further improvement of the present invention, in step S1, the alkaline agent used to adjust the pH value includes but is not limited to Na2CO3, NaOH, Ca(OH)2, CO2 and any combination of these agents;

[0015] As a further improvement of the present invention, in step S3, the multi-stage extraction-washing-stripping treatment specifically includes the following steps:

[0016] (1) extracting the crystallization mother liquor obtained in step S2 using a mixture of t-BAMBP and benzene and hydrogenated petroleum kerosene as an extraction organic phase to obtain an organic phase loaded with cesium and a small amount of rubidium, potassium, sodium and lithium and a raffinate;

[0017] (2) Adjusting the OH content of the raffinate in step (1) - After the concentration is reached, rubidium is extracted and purified using an extraction organic phase system consisting of a t-BAMBP extractant and a mixture of benzene and hydrogenated petroleum kerosene as a diluent to obtain an organic phase and a raffinate loaded with rubidium and a small amount of potassium, sodium and lithium;

[0018] (3) washing the loaded organic phases of steps (1) and (2) with pure water to obtain organic phases loaded with only cesium and rubidium and water washing liquid, respectively;

[0019] (4) stripping the washed organic phase of step (3) to obtain a blank organic phase and a stripping solution containing cesium salt and rubidium salt, wherein the blank organic phase is the regenerated organic phase;

[0020] The washing liquid of the extractant is mixed with the extraction liquid to perform countercurrent extraction on the extractant, so that the small amount of cesium washed away can be extracted into the extractant again to avoid loss; compared with the precipitation extraction method, unnecessary process flow can be reduced, the operation is simple, cost is saved, and the purity is higher.

[0021] As a further improvement of the present invention, the t-BAMBP concentration in the solution of the organic phase t-BAMBP and benzene and hydrogenated petroleum kerosene used is 1-2 mol / l, and the ratio of benzene to hydrogenated petroleum kerosene is 1-4:1. Since the active SO3H group in sulfonated kerosene is easy to produce precipitation with trace amounts of calcium and other heavy metals in the solution, the extraction system produces three-phase products, and the phase separation time is increased by more than 1 times compared with diethylbenzene and other benzenes. If the solution contains trace amounts of calcium, magnesium and heavy metal ions, the organic phase will produce fine particles, resulting in an increase in three-phase products; according to laboratory data, it can be known that the use of diethylbenzene as the diluent of the extraction system will greatly reduce the phase separation time, while the use of a mixture of diethylbenzene and hydrogenated petroleum kerosene will rarely produce three-phase products, and will not affect the phase separation time, and can also avoid the volatilization of diethylbenzene caused by temperature changes, thereby affecting the extraction effect.

[0022] As a further improvement of the present invention, the extraction phase ratio O / A in step (1) is 0.5-2:1, the extraction time is 3-5 min, and the extraction level is 3-6; the extraction phase ratio O / A in step (2) is 1-5:1, the extraction time is 3-5 min, and the extraction level is 3-6; when the pure water washing treatment is performed in step (3), the washing phase ratio O / A is 5-10:1, the washing time is 3-5 min, and the washing level is 3-6; when the stripping treatment is performed in step (4), the stripping phase ratio O / A is 5-10:1, the stripping solution concentration is 0.5-3 mol / l hydrochloric acid or sulfuric acid solution, the stripping time is 3-5 min, and the stripping level is 3-6.

[0023] As a further improvement of the present invention, in step S6, the stripping solution is subjected to deep oil removal and concentrated crystallization to obtain high-purity cesium salt and rubidium salt products. The oil removal method is to use oil-absorbing resin for oil removal, and after the oil-absorbing resin is saturated, it is backwashed with alkali solution. The backwashed liquid can be adjusted in steps S3 and S4 to obtain OH - Concentration used; Two groups of resins (SL300 and HP268) were selected for oil removal experiments. It was found that the unremoved stripping solution directly crystallized, and the cesium salt crystals and rubidium salt crystals produced were light brown, dark yellow, etc., while the cesium salt and rubidium salt were recrystallized after resin adsorption, and the cesium salt and rubidium salt appeared as standard colorless crystals;

[0024] As a further improvement of the present invention, in step S5, the variegated cesium salt crystals and rubidium salt crystals are redissolved to a nearly saturated solution, and the extraction phase ratio O / A is 1 to 10:1, the extraction time is 3 to 5 minutes, and the extraction level is 1; the washing phase ratio O / A is 5 to 10:1, the washing time is 3 to 5 minutes, and the washing level is 1; the stripping phase ratio O / A is 5 to 10:1, and the stripping solution concentration is 0.5 to 3 mol / l hydrochloric acid, sulfuric acid solution or dilute alkali solution is passed through CO2, the stripping time is 3 to 5 minutes, and the stripping level is 1; the stripping solution is then deeply deoiled, and the reduced pressure evaporation crystallization can obtain 99.95% high-purity cesium salt and rubidium salt;

[0025] As a further improvement of the present invention, the organic phase loaded with cesium and rubidium is stripped, and hydrochloric acid is used as the stripping acid, and cesium chloride and rubidium chloride are obtained by concentrating and crystallizing the stripping acid. Sulfuric acid is used as the stripping acid, and cesium sulfate and rubidium sulfate are obtained by concentrating and crystallizing the stripping acid. Dilute alkali solution is used to pass CO2 for stripping, and cesium carbonate and rubidium carbonate are obtained after crystallization.

[0026] As a further improvement of the present invention, t-BAMBP is used as the extractant, and different extraction conditions are used according to the selection characteristics of the extractant, so that the extraction system extracts cesium first and then extracts rubidium; therefore, the raffinate of cesium extraction is the raw material for rubidium extraction.

[0027] As a further improvement of the present invention, the waste brine from ore washing can be replaced by any one of solid waste treatment liquid, cesium mineral leaching liquid, and lithium mica leaching liquid. The cesium content of the waste brine from ore washing is between 0.01-30g / L, and the rubidium content is between 0.01-100g / L.

[0028] The beneficial effects of the present invention are as follows: the present invention firstly effectively removes non-alkali metal impurities in brine to ensure stable operation of evaporation and crystallization; then solves the problem of difficult phase separation in the extraction process by improving the extraction system; and effectively avoids high-energy-consuming and high-pollution links such as high-temperature calcination by using efficient impurity removal, extraction, evaporation and crystallization, and re-dissolution-re-extraction methods, and adopts oil-absorbing resin for oil removal, thereby preparing high-quality cesium salts and rubidium salts, improving product quality, saving costs, improving operating conditions, and reducing environmental pollution.

[0029] The method for extracting cesium salt and rubidium salt from cesium-containing ore-washing waste brine provided by the present invention can be verified through multiple rounds of experiments and can extract and prepare various types of high-quality and high-purity cesium salts and rubidium salts that meet the standards from wastewater. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The drawings constituting a part of this application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0031] Figure 1 It is a schematic diagram of the process of the present invention. DETAILED DESCRIPTION

[0032] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0033] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present application.

[0034] Embodiment 1: Using the present invention Figure 1 The process shown is to extract and purify cesium salt and rubidium salt from the waste brine (containing a large amount of alkali metals) of a high-chlorine mine. The main metal components are shown in the table below:

[0035] Table 1 Main metal components of high-chloride ore washing waste brine

[0036]

[0037] In this embodiment, a process for extracting cesium salt and rubidium salt from waste brine from ore washing includes the following steps:

[0038] 1. Precipitate and filter out solid impurities from the waste brine, add NaOH to adjust the pH value to 12, and add a precipitation aid to precipitate non-alkali metal ions such as calcium, magnesium, lead, zinc, and copper in the liquid, and control the concentration of impurity ions to be less than 10ppm. After filtering, adjust the pH value to neutral;

[0039] 2. The purified liquid in step 1 is subjected to evaporator crystallization, and a large amount of water, potassium chloride and sodium chloride are first evaporated to obtain a cesium and rubidium concentrate, the main components of which are shown in Table 2:

[0040] Table 2 Main metal components of evaporation mother liquor

[0041]

[0042] 3. Add NaOH to the above cesium concentrate to adjust OH - The concentration was adjusted to 0.25 mol / l, and multi-stage countercurrent extraction-washing-stripping was performed. The specific steps are as follows:

[0043] Extraction: Add the above cesium concentrate to OH - The concentration was adjusted to 0.25 mol / l, t-BAMBP (4-tert-butyl-2-(α-methylbenzyl)phenol) was used as an extractant, a mixture of diethylbenzene and hydrogenated petroleum kerosene was used as a diluent, the extractant concentration was configured to be between 1 mol / L, the ratio of benzene to hydrogenated petroleum kerosene was 1:1, the extraction phase ratio O / A was 0.5:1, the mixing time was 5 min, and the extraction level was 3;

[0044] Washing: In the washing treatment, the washing phase ratio O / A is 5:1, the washing time is 5 minutes, and the washing stages are 3; in the countercurrent washing, the washing liquid is mixed with the raffinate.

[0045] Stripping: the stripping phase ratio O / A in the treatment is 5:1, the stripping solution concentration is 0.5 mol / L hydrochloric acid or sulfuric acid solution, the stripping time is 5 min, and the stripping level is 3; the organic phase after stripping is returned to the first step for extraction again to avoid repeated use of new organic phase and achieve internal circulation of the organic phase system; as shown in Table 3, during the entire extraction process, the extraction yield of cesium can reach up to 99.9% and the purity is 99.5%.

[0046] The extraction room temperature was 15°C, and an extraction tank with a mixing chamber volume of 1 L was used for a continuous experiment for 10 days, during which no three-phase product was generated;

[0047] Table 3 Main metal components in the stripping solution of cesium extraction from brine from high-chloride ore washing

[0048]

[0049] 4. A very small amount of organic phase will be entrained in the stripping liquid from the stripping. After the stripping liquid is treated for oil separation, it is deoiled with oil-absorbing resin, then evaporated and crystallized under reduced pressure, and then redissolved with pure water to a saturated solution. The saturated solution of cesium salt is subjected to single-stage extraction, washing, and stripping, and then deoiled, evaporated and crystallized under reduced pressure to obtain cesium salt crystals with a purity of 99.95%.

[0050] Table 4 Main metal components in crude cesium salt re-dissolution, extraction, deep deoiling crystallization

[0051]

[0052] 5. Add NaOH to the cesium extract residue. - The concentration was adjusted to 1.1 mol / l, and multi-stage countercurrent extraction-washing-stripping was performed. The specific steps are as follows:

[0053] Extraction: Take the OH of the raffinate from the above cesium extraction - The concentration was adjusted to 1.1 mol / l, t-BAMBP (4-tert-butyl-2-(α-methylbenzyl)phenol) was used as the extractant, a mixture of diethylbenzene and hydrogenated petroleum kerosene was used as the diluent, the extractant concentration was configured to be between 1 mol / L, the ratio of benzene to hydrogenated petroleum kerosene was 1:1, the extraction phase ratio O / A was 1:1, the mixing time was 5 min, and the extraction level was 3;

[0054] Washing: In the washing treatment, the washing phase ratio O / A is 5:1, the washing time is 5 minutes, and the washing stages are 3; in the countercurrent washing, the washing liquid is mixed with the raffinate.

[0055] Stripping: In the treatment, the stripping phase ratio O / A is 5:1, the stripping solution concentration is 0.5 mol / L hydrochloric acid or sulfuric acid solution, the stripping time is 5 min, and the stripping level is 3; the organic phase after stripping is returned to the first step for extraction again to avoid repeated use of new organic phase and achieve internal circulation of the organic phase system; as shown in Table 5, during the entire extraction process, the extraction yield of rubidium can reach up to 99.9% and the purity is 99.5%.

[0056] The extraction room temperature was 15°C, and an extraction tank with a mixing chamber volume of 1 L was used for a continuous experiment for 10 days, during which no three-phase product was generated;

[0057] Table 5 Main metal components in the stripping solution of rubidium extraction process of high-chloride ore washing waste brine

[0058]

[0059] 6. A very small amount of organic phase will be entrained in the stripping liquid from the stripping. After the stripping liquid is treated for oil separation, it is deoiled with oil-absorbing resin, then evaporated and crystallized under reduced pressure, and then redissolved with pure water to a saturated solution. The saturated solution of rubidium salt is subjected to single-stage extraction, washing, and stripping, and then deoiled, evaporated and crystallized under reduced pressure to obtain rubidium salt crystals with a purity of 99.95%.

[0060] Table 6 Main metal components in crude rubidium salt re-dissolution, extraction, deep deoiling crystallization

[0061]

[0062] Embodiment 2: Using the present invention Figure 1 The process flow shown is to extract and purify cesium salt and rubidium salt from a high-chlorine solid waste leachate (containing a large amount of alkali metals). The main metal components are shown in the table below:

[0063] Table 7 Main metal components of high-chlorine solid waste leachate

[0064]

[0065]

[0066] In this embodiment, a process for extracting cesium salt from high-chloride solid waste leachate includes the following steps:

[0067] 1. Filter impurities from the solid waste leachate, add Na2CO3+NaOH to adjust the pH value to 12.5, and add precipitation aids to precipitate non-alkali metal ions such as calcium, magnesium, lead, zinc, and copper in the liquid, control the concentration of impurity ions to be less than 10ppm, and adjust the pH value to neutral after filtration;

[0068] 2. The purified liquid in step 1 is subjected to evaporator crystallization, and a large amount of water, potassium chloride and sodium chloride are first evaporated to obtain a concentrated solution of cesium and rubidium;

[0069] Its main components are shown in Table 8:

[0070] Table 8 Main metal components of evaporation mother liquor of high-chlorine solid waste leachate after impurity removal:

[0071]

[0072] 3. After evaporation, the liquid was given the data in Table 8. Na2CO3+NaOH, OH was added to the liquid. - The concentration was adjusted to within 0.5 mol / l, and multi-stage countercurrent extraction-washing-stripping was performed.

[0073] The specific steps are as follows:

[0074] Extraction: Put the liquid OH -The concentration is adjusted to 0.5 mol / l, t-BAMBP (4-tert-butyl-2-(α-methylbenzyl)phenol) is used as the extractant, diethylbenzene or a mixture of other benzenes and hydrogenated petroleum kerosene is used as the diluent, the concentration of the extractant is configured to be between 1.5 mol / l, the ratio of benzene to hydrogenated petroleum kerosene is 2:1, the extraction phase ratio O / A is 1:1, the mixing time is 5 minutes, and the extraction level is 5 levels;

[0075] Washing: In the washing treatment, the washing phase ratio O / A is 10:1, the washing time is 5 minutes, and the number of washing stages is 6; in the countercurrent washing, the washing liquid and the raffinate are mixed together.

[0076] Stripping: The stripping phase ratio O / A in the treatment is 10:1, the stripping solution concentration is 2mol / l hydrochloric acid solution, the stripping time is 5min, and the stripping level is 6 levels; the organic phase after stripping returns to the first step for extraction again to avoid repeated use of new organic phase and achieve internal circulation of the organic phase system; (Indicate the size of the extraction tank used for the 15-day continuous cascade extraction experiment) As shown in Table 9, during the entire extraction process, the cesium extraction yield can reach up to 99.9%, and the cesium salt purity is 99.5%. The extraction room temperature is 15°C, and the extraction tank with a mixing chamber volume of 1L is used for 10 days of continuous experiments, during which no three-phase products are generated;

[0077] Table 9 Main metal components in the stripping solution during the extraction of cesium from high-chlorine solid waste leachate

[0078]

[0079] 4. The stripping liquid from the stripping still contains a very small amount of organic phase. The stripping liquid is deoiled with oil-absorbing resin, then evaporated and crystallized under reduced pressure, and then redissolved with pure water to a saturated solution. The saturated solution of cesium salt is subjected to single-stage extraction, washing, and stripping, and then deoiled, evaporated and crystallized under reduced pressure to obtain cesium salt crystals with a purity of 99.95%.

[0080] Table 10 Main metal components in crude cesium salt re-dissolution, extraction, deep deoiling crystallization

[0081]

[0082] 5. Add Na2CO3+NaOH to the cesium extract residue. - The concentration was adjusted to 1.5 mol / l, and multi-stage countercurrent extraction-washing-stripping was performed. The specific steps are as follows:

[0083] Extraction: Take the OH of the raffinate from the above cesium extraction -The concentration was adjusted to 1.5 mol / l, t-BAMBP (4-tert-butyl-2-(α-methylbenzyl)phenol) was used as an extractant, a mixture of diethylbenzene and hydrogenated petroleum kerosene was used as a diluent, the extractant concentration was configured to be between 1 mol / L, the ratio of benzene to hydrogenated petroleum kerosene was 1:1, the extraction phase ratio O / A was 3:1, the mixing time was 5 min, and the extraction level was 5;

[0084] Washing: In the washing treatment, the washing phase ratio O / A is 7:1, the washing time is 5 minutes, and the number of washing stages is 5; in the countercurrent washing, the washing liquid and the raffinate are mixed together.

[0085] Stripping: In the treatment, the stripping phase ratio O / A is 7:1, the stripping solution concentration is 0.5 mol / L hydrochloric acid or sulfuric acid solution, the stripping time is 5 min, and the stripping level is 5; the organic phase after stripping is returned to the first step for extraction again to avoid repeated use of new organic phase and achieve internal circulation of the organic phase system; as shown in Table 10, during the entire extraction process, the extraction yield of rubidium can reach up to 99.9% and the purity is 99.5%.

[0086] The extraction room temperature was 15°C, and an extraction tank with a mixing chamber volume of 1 L was used for a continuous experiment for 10 days, during which no three-phase product was generated;

[0087] Table 11 Main metal components in the stripping solution during the extraction of rubidium from high-chlorine solid waste leachate

[0088]

[0089] 6. A very small amount of organic phase will be entrained in the stripping liquid from the stripping. After the stripping liquid is treated for oil separation, it is deoiled with oil-absorbing resin, then evaporated and crystallized under reduced pressure, and then redissolved with pure water to a saturated solution. The saturated solution of rubidium salt is subjected to single-stage extraction, washing, and stripping, and then deoiled, evaporated and crystallized under reduced pressure to obtain rubidium salt crystals with a purity of 99.95%.

[0090] Table 12 Main metal components in the re-dissolution, extraction and deep de-oiling crystallization of crude rubidium salt

[0091]

[0092]

[0093] Example 3: Using the process shown in the patent flow chart, cesium salt is extracted and purified from a salt lake brine (containing a large amount of alkali metals). The main metal components are shown in the following table:

[0094] Table 13 Main metal components of salt lake brine:

[0095]

[0096] In this embodiment, a process for extracting cesium salt from salt lake brine comprises the following steps:

[0097] 1. Filter impurities from salt lake brine, add Na2CO3+CO2 to adjust the pH value to 13, and add precipitation aids to precipitate non-alkali metal ions such as calcium, magnesium, lead, zinc, and copper in the liquid, and control the concentration of impurity ions to be less than 10ppm. After filtering, adjust the pH value to neutral;

[0098] 2. The purified liquid in step 1 is subjected to evaporator crystallization, and a large amount of water, potassium chloride and sodium chloride are first evaporated to obtain a concentrated solution of cesium and rubidium;

[0099] Table 14 Main metal components of salt lake brine after evaporation

[0100]

[0101] 3. After evaporation, the liquid obtained the data in Table 14. Na2CO3+CO2 was added to the above cesium concentrate to adjust the OH - The concentration was adjusted to 1.0 mol / l, and multi-stage countercurrent extraction-washing-stripping was performed;

[0102] The specific steps are as follows:

[0103] Extraction: Put the liquid OH - The concentration is adjusted to 1.0 mol / l, t-BAMBP (4-tert-butyl-2-(α-methylbenzyl)phenol) is used as the extractant, diethylbenzene or a mixture of other benzenes and hydrogenated petroleum kerosene is used as the diluent, the extractant concentration is configured to 2 mol / L, the ratio of benzene to hydrogenated petroleum kerosene is 4:1, the extraction phase O / A is 2:1, the mixing time is 3 to 5 minutes, and the extraction stage is 6;

[0104] Washing: In the washing treatment, the washing phase ratio O / A is 10:1, the washing time is 5 minutes, and the number of washing stages is 6; in the countercurrent washing, the washing liquid and the raffinate are mixed together.

[0105] Stripping: the stripping phase ratio O / A in the treatment is 10:1, the stripping solution concentration is 3 mol / L hydrochloric acid solution, the stripping time is 5 min, and the stripping level is 6; the organic phase after stripping is returned to the first step for extraction again to avoid repeated use of new organic phase and achieve internal circulation of the organic phase system; as shown in Table 15, during the entire extraction process, the extraction yield of cesium can reach up to 99.4%, and the purity of cesium salt is 99%.

[0106] Table 15 Main metal components in the stripping solution during the extraction process of the mother liquor from the salt lake brine evaporation

[0107]

[0108] 4. The stripping solution from stripping will also contain a very small amount of organic phase. The stripping solution is deoiled with oil-absorbing resin, then evaporated and crystallized under reduced pressure, and then redissolved with pure water to a saturated solution. The saturated solution of cesium salt is subjected to single-stage extraction, washing, stripping, deoiling, and decompression evaporation and crystallization to obtain cesium salt crystals with a purity of 99.95%. The extraction room temperature is 13°C, and an extraction tank with a mixing chamber volume of 1L is used for 15 days of continuous experiments, during which no three-phase material is generated.

[0109] Table 16 Main metal components in crude cesium salt re-dissolution, extraction, deep deoiling crystallization

[0110]

[0111] 5. Add Na2CO3+CO2 to the cesium extract residue and add OH - The concentration was adjusted to 1.8 mol / l, and multi-stage countercurrent extraction-washing-stripping was performed. The specific steps are as follows:

[0112] Extraction: Take the OH of the raffinate from the above cesium extraction - The concentration was adjusted to 1.8 mol / l, t-BAMBP (4-tert-butyl-2-(α-methylbenzyl)phenol) was used as the extractant, a mixture of diethylbenzene and hydrogenated petroleum kerosene was used as the diluent, the extractant concentration was configured to be between 1 mol / L, the ratio of benzene to hydrogenated petroleum kerosene was 1:1, the extraction phase ratio O / A was 5:1, the mixing time was 5 min, and the extraction level was 5 levels;

[0113] Washing: In the washing treatment, the washing phase ratio O / A is 10:1, the washing time is 5 minutes, and the number of washing stages is 6; in the countercurrent washing, the washing liquid and the raffinate are mixed together.

[0114] Stripping: the stripping phase ratio O / A in the treatment is 10:1, the stripping solution concentration is 0.5 mol / L hydrochloric acid or sulfuric acid solution, the stripping time is 5 min, and the stripping level is 6; the organic phase after stripping is returned to the first step for extraction again to avoid repeated use of new organic phase and achieve internal circulation of the organic phase system; as shown in Table 17, during the entire extraction process, the extraction yield of rubidium can reach up to 99.9% and the purity is 99.5%.

[0115] The extraction room temperature was 15°C, and an extraction tank with a mixing chamber volume of 1 L was used for a continuous experiment for 10 days, during which no three-phase product was generated;

[0116] Table 17 Main metal components in the stripping solution of rubidium extraction from salt lake brine

[0117]

[0118] 6. A very small amount of organic phase will be entrained in the stripping liquid from the stripping. After the stripping liquid is treated for oil separation, it is deoiled with oil-absorbing resin, then evaporated and crystallized under reduced pressure, and then redissolved with pure water to a saturated solution. The saturated solution of rubidium salt is subjected to single-stage extraction, washing, and stripping, and then deoiled, evaporated and crystallized under reduced pressure to obtain rubidium salt crystals with a purity of 99.95%.

[0119] Table 18 Main metal components in crude rubidium salt re-dissolution, extraction, deep deoiling crystallization

[0120]

[0121] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, component splitting or combination, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for extracting cesium salt and rubidium salt from waste brine from ore washing, It is characterized in that The following steps are involved: S1. Filter the solid impurities carried by the previous process from the waste brine containing rubidium and cesium, adjust the pH value to above 12 with an alkaline agent, introduce a carbon source, and perform complex phase precipitation on the metal ions of calcium, magnesium, lead, zinc, and copper. The concentration of non-alkali metal ions is controlled below 10 ppm to obtain a feed solution to be evaporated; S2, subjecting the liquid obtained in S1 to reduced pressure evaporation and crystallization to obtain potassium chloride and sodium chloride products, and by controlling the crystallization sequence and crystallization point, 99% of rubidium and cesium enter the crystallization mother liquor; S3, the OH of the crystallization mother solution obtained in step S2 - The concentration is adjusted to a range of 0.25-1.0 mol / l, and a box-type extraction tank is used to perform cascade countercurrent extraction-washing-stripping treatment to obtain a stripping solution and a raffinate containing a cesium salt; S4, the raffinate OH from step S3 cesium extraction - The concentration is adjusted to a range of 1.1-1.8 mol / l, and a cascade countercurrent extraction-washing-stripping process is performed using an extraction tank to obtain a stripping solution and a raffinate containing a rubidium salt; S5, removing oil from the weakly acidic stripping solution treated in steps S3 and S4, and performing reduced pressure evaporation and crystallization to obtain preliminary cesium salt crystals and rubidium salt crystals; S6, the cesium salt crystals and rubidium salt crystals obtained in step S5 are redissolved to obtain cesium salt solution and rubidium salt solution respectively, and then extracted with 1-3 levels, washed with 1-2 levels, and then stripped to obtain cesium salt solution and rubidium salt solution, and after degreasing, evaporated and crystallized under reduced pressure to obtain finished cesium salt and rubidium salt.

2. A method for extracting cesium salt and rubidium salt from waste brine of ore washing according to claim 1, Features: In step S1, the alkaline agent used to adjust the pH value and precipitate the non-alkali metal ions is Na 2 CO 3 , NaOH, Ca(OH) 2 and CO 2 At least one of .

3. A method for extracting cesium salt and rubidium salt from waste brine of ore washing according to claim 1, Features: In step S3, the multi-stage extraction-washing-stripping process specifically includes the following steps: (1) extracting and purifying cesium from the crystallization mother liquor obtained in step S2 using an extraction organic phase system composed of a t-BAMBP extractant and a mixture of benzene and hydrogenated petroleum kerosene as a diluent to obtain an organic phase loaded with cesium and an alkaline raffinate containing rubidium, potassium, sodium and lithium; (2) Adjusting the OH content of the raffinate in step (1) - After the concentration is reached, rubidium is extracted and purified using an extraction organic phase system consisting of a t-BAMBP extractant and a mixture of benzene and hydrogenated petroleum kerosene as a diluent to obtain an organic phase loaded with rubidium and an alkaline raffinate containing potassium, sodium and lithium; (3) washing the loaded organic phases of steps (1) and (2) with pure water to obtain an organic phase loaded with only cesium and rubidium and a water washing liquid; (4) performing stripping treatment on the washed organic phase of step (3) to obtain a blank organic phase and a stripping solution containing cesium salt and rubidium salt, wherein the blank organic phase is regenerated and reused.

4. A method for extracting cesium salt and rubidium salt from waste brine of ore washing according to claim 1, Features: In step S5, the oil removal method is to use oil absorbing resin to remove oil, and after the oil absorbing resin is saturated, it is backwashed with alkali solution. The alkali solution obtained by backwashing can be used to adjust the OH in step S3. - Concentration used.

5. A method for extracting cesium salt and rubidium salt from waste brine of ore washing according to claim 3, Features: The concentration of t-BAMBP in the extraction organic phase t-BAMBP and the solution of benzene and hydrogenated petroleum kerosene is 1-2 mol / l, and the ratio of benzene to hydrogenated petroleum kerosene is 1 / 4-4:

1.

6. A method for extracting cesium salt and rubidium salt from waste brine of ore washing according to claim 3, Features: The extraction phase ratio O / A in step (1) is 0.5 to 2:1, the extraction time is 3 to 5 minutes, and the extraction stage is 3 to 6; The extraction phase ratio O / A in step (2) is 1-5:1, the extraction time is 3-5 min, and the extraction level is 3-6; When the pure water washing treatment is performed in step (3), the washing phase ratio O / A is 5 to 10:1, the washing time is 3 to 5 minutes, and the washing stage number is 3 to 6; When the stripping treatment is performed in step (4), the stripping phase ratio O / A is 5 to 10:1, the stripping solution concentration is 0.5 to 3 mol / L hydrochloric acid solution, the stripping time is 3 to 5 min, and the stripping stage is 3 to 6.

7. A method for extracting cesium salt and rubidium salt from waste brine of ore washing according to claim 1, Features: The cesium content of the waste brine from ore washing is between 0.01-30 g / L, and the rubidium content is between 0.01-100 g / L.

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