CN109824068B

CN109824068B - Extraction of Rb from Low-concentration brine+And method for producing highly pure rubidium salt

Info

Publication number: CN109824068B
Application number: CN201910266686.1A
Authority: CN
Inventors: 王磊; 王琎; 范哲远; 陈立成; 黄丹曦; 宫飞祥
Original assignee: Shaanxi Membrane Separation Technology Research Institute Co ltd
Current assignee: Shaanxi Membrane Separation Technology Research Institute Co ltd
Priority date: 2019-04-03
Filing date: 2019-04-03
Publication date: 2021-06-29
Anticipated expiration: 2039-04-03
Also published as: CN109824068A

Abstract

The invention belongs to the technical field of hydrometallurgy, and particularly relates to a method for extracting Rb from low-concentration brine⁺And a method for producing a highly pure rubidium salt, comprising the steps of: passing the coarsely filtered bittern through Rb⁺Adsorbing saturation by an adsorption column, stopping pumping brine and flushing Rb by pure water⁺Adsorption column, which is subsequently washed with ammonium salt solution for Rb⁺Eluting to obtain a first rubidium-rich solution; concentrating the first rubidium-rich solution to obtain a second rubidium-rich solution; adding aluminum sulfate into the second rubidium-rich solution, and recrystallizing to obtain high-purity rubidium aluminum sulfate crystals; adding barium hydroxide into the solution obtained after dissolving the rubidium aluminum sulfate crystal to obtain a rubidium hydroxide solution; and adding acid into the rubidium hydroxide solution, and recrystallizing to obtain the high-purity rubidium salt. The invention provides a method for extracting Rb from low-concentration brine⁺The method for preparing the high-purity rubidium salt has high preparation efficiency and environment-friendly process, and various rubidium salts with the purity as high as 99.99% are prepared.

Description

Extraction of Rb from Low-concentration brine+And method for producing highly pure rubidium salt

Technical Field

The invention belongs to the technical field of hydrometallurgy, and particularly relates to a method for extracting Rb from low-concentration brine⁺And a method for producing a highly pure rubidium salt.

Background

Rubidium (Rb) is an active metal with silvery white metallic luster, and due to its unique physicochemical properties, it has important applications in the traditional fields of electronic devices, photovoltaic cells, catalysts, special glass, biochemical medicine, and the like, and has attracted great attention in some emerging fields such as magnetohydrodynamic power generation, thermionic conversion power generation, ion propulsion engine rockets, laser conversion power devices, and the like, and particularly, a thermoelectric converter made of Rubidium, such as being used with an atomic reactor, can realize thermionic thermonuclear power generation inside the reactor.

The rubidium resources in China mainly exist in the lepidolite and other ores in an associated state, and a large amount of rubidium resources also exist in salt lake brine in Tibet, Qinghai and other places in China. However, each rubidium resource is usually a complex multi-element open system, Rb⁺Usually with other metal elements (Li)⁺、Na⁺、K⁺、Mg²⁺、Ca²⁺) Coexisting, additionally of lower grade, especially with Rb⁺K with similar physicochemical properties⁺Effective separation is difficult to achieve using conventional methods.

At present, the separation and extraction method of the most widely and mature rubidium resource is a chemical solvent extraction method, on one hand, the price of an extracting agent is high, and more importantly, the environmental problems caused by solvent volatilization, emission and the like cannot be avoided in the extraction process, so that the sustainable development of the technology is restricted, for example, the problem exists in a bispicramine-nitrobenzene extraction system disclosed in Chinese patent CN86101311A, and the problem exists in a 4-tert-butyl-2 (alpha-methylbenzyl) phenol-sulfonated kerosene extraction system disclosed in Chinese patent CN101966399A and CN 108677006A; the method for purifying rubidium by recrystallization by utilizing the solubility difference of potassium alum, rubidium alum, cesium alum and the like, which is disclosed by Chinese patent CN201210307423.9, only uses brine with higher rubidium content, and has the defects of more recrystallization times and high energy consumption when the brine is directly recrystallized to remove impurities, and the effective recovery and utilization of the ubiquitous low-concentration rubidium-containing brine are still a great problem which restricts the application and popularization of rubidium and rubidium salt in China; in addition, the related art disclosed in the domestic literature is still very deficient in the preparation of a highly pure rubidium salt product.

In order to solve the problems, the invention provides a method for extracting Rb from low-concentration brine⁺And a method for producing a highly pure rubidium salt.

Disclosure of Invention

One object of the present invention is to provide a method for extracting Rb from low-concentration brine⁺And a method for preparing a highly pure rubidium salt, which solves the problem of extracting Rb from brine by using a conventional method⁺The environment pollution problem is generated.

It is yet another object of the present invention to provide a method for extracting Rb from low-concentration brine⁺And a method for producing a highly pure rubidium salt by using Rb in brine⁺The concentration can be as low as 40mg/L, the purity of the prepared rubidium salt can reach 99.99 percent, the whole preparation process is relatively simple, and the preparation efficiency is high.

To achieve these objects and other advantages in accordance with the purpose of the invention, the present invention provides a method for extracting Rb from a low concentration brine⁺And a method for preparing a highly pure rubidium salt, comprising the steps of:

passing the coarsely filtered bittern through Rb⁺Adsorbing with adsorption column, stopping pumping bittern, washing Rb with pure water⁺Adsorption column, which is subsequently washed with ammonium salt solution for Rb⁺Eluting to obtain a first rubidium-rich solution;

concentrating the first rubidium-rich solution to obtain a second rubidium-rich solution;

adding aluminum sulfate into the second rubidium-rich solution, and recrystallizing to obtain high-purity rubidium aluminum sulfate crystals;

adding barium hydroxide into the solution obtained after dissolving the rubidium aluminum sulfate crystal to obtain a rubidium hydroxide solution;

and adding acid into the rubidium hydroxide solution, and recrystallizing to obtain the high-purity rubidium salt.

The purity of the rubidium salt prepared by the method provided by the invention can reach 99.99%, and the method is simple in preparation process, pollution-free in process, environment-friendly and economical.

Preferably, said Rb is⁺The adsorption column is filled with Rb⁺Adsorption column for adsorbing microspheres, Rb⁺The adsorption microspheres comprise the following raw materials in percentage by mass:

6-14% of polyvinyl alcohol, 0.4-1.5% of sodium alginate, 0.4-1.5% of sodium silicate, 20-60% of rubidium ion exchange material and 30-60% of water.

9-12% of polyvinyl alcohol, 0.8-1.3% of sodium alginate, 0.8-1.3% of sodium silicate, 35-50% of rubidium ion exchange material and 40-50% of water.

According to the invention, sodium alginate and sodium silicate are doped into polyvinyl alcohol, so that the problems of adhesion, poor mechanical strength and the like are solved while the hydrophilicity of the polyvinyl alcohol is maintained, and the forming and durability of the adsorption microspheres are improved.

Preferably, the rubidium ion exchange material is one or more of heteropoly acid salts with Keggin structures, and the general structural formula of the heteropoly acid salts is [ XM [ ]₁₂O₄₀]ⁿWhere, X ═ P, Si, Ge, As, and M ═ Mo, W.

The rubidium ion adsorption microspheres are used for filling the adsorption column to adsorb rubidium ions, the adsorption-desorption process is fast, the adsorption capacity is large, the separation effect of rubidium and associated impurity cations is good, the mechanical strength is good, the method is suitable for industrial large-scale column loading, and the service life of the adsorption column is greatly prolonged.

Preferably, the brine is natural rubidium-containing brine or leachate of rubidium-containing ore, and Rb in the brine⁺The content is more than or equal to 40mg/L, so that the high-efficiency adsorption and recovery of rubidium and the preparation of high-purity rubidium salt can be realized.

Preferably, the coarsely filtered brine is passed through Rb⁺Adsorbing with adsorption column, stopping pumping bittern, washing Rb with pure water⁺After adsorbing the column, dissolving with ammonium saltFlushing the Rb with a liquid⁺And (3) adsorbing the column, and eluting to obtain a first rubidium-rich solution, wherein the first rubidium-rich solution specifically comprises:

pumping the coarsely filtered bittern into Rb at a speed of 0.3-3t/h⁺The adsorption column is used for stopping pumping brine after adsorption is carried out until saturation;

washing the Rb with pure water at a rate of 1.2-2.4t/h⁺After adsorbing the column, when the Rb is⁺Stopping washing when the conductivity at the outlet of the adsorption column is lower than 100 mus/cm;

passing ammonium salt solution through the Rb at a rate of 0.3-3t/h⁺Adsorption column, at the outlet Rb of adsorption column⁺The concentration is close to Rb in brine⁺And when the concentration is high, ending the desorption process, and eluting to obtain the first rubidium-rich solution.

When the first rubidium-rich solution is obtained, according to different rubidium content in brine, the series adsorption-series desorption mode may be repeatedly carried out for many times so as to achieve the first rubidium-rich solution with qualified concentration.

Preferably, the ammonium salt is one of ammonium chloride, ammonium sulfate and the like, and the NH is⁴⁺The concentration is 0.5-4 mol/L.

The ammonium salt concentration is high, the desorption speed is high, the efficiency is high, but a large amount of ammonium ions can be introduced into the system, and the desorption speed is low when the ammonium salt concentration is proper, but the ammonium salt concentration in the obtained desorption solution is low, so that the ammonium salt can be easily removed.

Preferably, Rb in the first rubidium-rich solution⁺Rb in the second rubidium-rich solution with the concentration of more than 500mg/L⁺The concentration is 7-9 g/L.

Wherein qualified Rb in the first rubidium-rich solution⁺The concentration is higher than 500mg/L-1g/L, and the concentration ensures that the subsequent concentration process is finished with low energy consumption and low cost;

the concentration of the second rubidium-rich solution is too high, so that a large amount of energy is consumed in the concentration process, the requirement on concentration equipment is high, and the production cost is increased; the low concentration of the rubidium-rich solution increases the recrystallization frequency of subsequent impurity removal, so that the recrystallization process is complex, the production cost of rubidium salt is indirectly improved, and the production efficiency is reduced.

Preferably, adding aluminum sulfate into the second rubidium-rich solution, and crystallizing to obtain rubidium aluminum sulfate crystals specifically comprises:

adding aluminum sulfate into the second rubidium-rich solution containing rubidium sulfate and potassium sulfate, heating and dissolving at 70-90 ℃, cooling to room temperature for crystallization, and performing solid-liquid separation to obtain rough rubidium aluminum sulfate crystals;

re-dissolving and crystallizing the rough rubidium aluminum sulfate crystal, wherein the re-crystallizing step needs to be carried out for 2-4 times according to the difference of the concentration of the second rubidium rich solution, so as to obtain high-purity rubidium aluminum sulfate crystal;

wherein the mass ratio of the aluminum sulfate to the potassium sulfate is 0.35-0.45: 1;

in the high purity aluminum sulfate crystal, the concentration of the hetero-ions is less than 0.01%.

Adding aluminum sulfate into the second rubidium-rich solution according to a certain proportion, crystallizing to obtain rough aluminum rubidium sulfate with the purity higher than 87%, and performing recrystallization purification for several times according to the concentration of the second rubidium-rich solution to obtain high-purity aluminum rubidium sulfate crystals with the purity of more than 99.99%, thereby completing Rb crystal production⁺And the impurities are removed for the first time, so that the realization of the subsequent high-purity rubidium salt with lower production cost is ensured. (ii) a

Wherein, the control range of the mass ratio of the aluminum sulfate to the potassium sulfate is optimal, and is lower than 0.35, so the crystallization times need to be increased, the crystallization temperature is lower, the industrial cost is increased, and is higher than 0.45, and the purity of the obtained rubidium aluminum sulfate crystal is low.

Preferably, the acid added to the rubidium hydroxide solution may be one of hydrochloric acid, sulfuric acid, nitric acid and carbonic acid, and the corresponding series of high purity rubidium salt products produced are high purity rubidium chloride, rubidium sulfate, rubidium nitrate and rubidium carbonate.

Specifically, rubidium salts having different purities, i.e., purities of more than 99% to 99.99%, can be obtained according to the number of times of recrystallization of the rubidium salt.

The invention has the advantages of

1. The invention provides a method for extracting low-concentration brineTo extract Rb⁺And a method for producing a highly pure rubidium salt using Rb⁺The fixing material of the adsorption column has good hydrophilicity, and is favorable for Rb in the solution⁺The rubidium ions are fully contacted with the effective components in the microspheres, the adsorption-desorption process is fast, the adsorption capacity is large, and the separation efficiency of rubidium and associated impurity cations is high;

2. the invention provides a method for extracting Rb from low-concentration brine⁺In the method for preparing the rubidium salt, the rubidium ion adsorption column is adopted, so that the mechanical strength of the ion exchanger is obviously improved, the water-soluble expansibility is inhibited, and the service life of the adsorption microspheres serving as the ion exchanger is prolonged;

3. the invention provides a method for extracting Rb from low-concentration brine⁺The method for preparing the high-purity rubidium salt is simple in preparation process, low in cost, high in adsorption efficiency and beneficial to popularization and use;

4. the invention provides a method for extracting Rb from low-concentration brine⁺A method for producing a rubidium salt having a high purity, which can produce a series of rubidium salts such as rubidium chloride, rubidium sulfate and rubidium carbonate having a purity of more than 99.99%;

5. the invention provides a method for extracting Rb from low-concentration brine⁺And a method for producing a highly pure rubidium salt which can act on Rb⁺Carrying out high-efficiency recovery on rubidium from natural brine with the concentration of more than or equal to 40mg/L and from a rubidium-containing ore leaching solution;

6. the invention provides a method for extracting Rb from low-concentration brine⁺The method for preparing the high-purity rubidium salt has the advantages of simple process, low production cost and no pollution, and can realize the Rb in the brine⁺The effective utilization of the water is realized.

Drawings

FIG. 1 is a process for extracting Rb from brine according to the present invention⁺And a flow chart of a method for producing a rubidium salt.

Detailed Description

The present invention is further described in detail below with reference to examples so that those skilled in the art can practice the invention with reference to the description.

It should be understood that terms such as "having," "including," and "comprising," as used herein, do not preclude the presence or addition of one or more other combinations.

The raw water selected by the invention is natural rubidium-containing brine or a leaching solution of rubidium-containing ore, wherein Rb is⁺The content is more than 40mg/L, namely the Rb is realized⁺The method has the advantages of high-efficiency adsorption and separation and realization of preparation of a series of high-purity rubidium salts such as rubidium chloride, rubidium sulfate, rubidium carbonate and the like.

The rubidium ion exchange material is one or more of heteropoly acid salts with Keggin structures, and the general structural formula of the heteropoly acid salts is [ XM [ ]₁₂O₄₀]ⁿWhere X ═ P, Si, Ge, As, and M ═ Mo, W, ammonium phosphomolybdate and ammonium tungstomolybdate were selected in the present invention.

The present invention provides the following examples to illustrate the method of extracting rubidium ions from brine and producing a highly pure rubidium salt.

Example 1

The rubidium ion adsorption microsphere comprises a solution prepared according to the following mass percentages:

14% of polyvinyl alcohol, 1.5% of sodium alginate, 0.4% of sodium silicate, 24.1% of ammonium phosphomolybdate and 60% of water.

Example 2

The rubidium ion adsorption microsphere comprises the following raw materials in percentage by mass:

10% of polyvinyl alcohol, 1% of sodium alginate, 1% of sodium silicate, 45% of ammonium phosphomolybdate and 43% of water.

Example 3

6% of polyvinyl alcohol, 0.8% of sodium alginate, 1.5% of sodium silicate, 60% of ammonium phosphomolybdate and 31.7% of water.

Example 4

9% of polyvinyl alcohol, 0.4% of sodium alginate, 0.6% of sodium silicate, 50% of ammonium tungsten molybdate and 40% of water.

Example 5

12% of polyvinyl alcohol, 1.3% of sodium alginate, 0.7% of sodium silicate, 46% of ammonium tungsten molybdate and 50% of water.

Example 6

14% of polyvinyl alcohol, 1.5% of sodium alginate, 1.3% of sodium silicate, 35% of ammonium tungsten molybdate and 48.2% of water.

According to the rubidium ion adsorption microsphere, sodium alginate and sodium silicate are doped into polyvinyl alcohol, the hydrophilicity of the polyvinyl alcohol is kept to ensure the adsorption-desorption speed, meanwhile, the problems of adhesion, poor mechanical strength and the like are solved, and the forming and durability of the adsorption microsphere are improved.

The Rb is⁺The adsorption microsphere uses a rubidium ion exchange material as a fixing material, has good hydrophilicity, is beneficial to the full contact between rubidium ions in a solution and effective components in the microsphere, and has the advantages of fast adsorption-desorption process, large adsorption capacity and high efficiency.

The rubidium ion adsorption microspheres are used for filling the adsorption column to adsorb rubidium ions, the adsorption-desorption process is fast, the adsorption capacity is large, the efficiency is high, and the service life of the adsorption column is prolonged to more than half a year.

The rubidium ion adsorption microspheres in examples 1 to 6 are filled into an adsorption column to extract Rb from brine as the invention⁺And an adsorption column in the method for producing a rubidium salt.

The invention provides a method for extracting rubidium ions from brine and preparing high-purity rubidium salt, which comprises the following steps:

step 101, passing the rough-filtered brine through Rb⁺Adsorbing with adsorption column, stopping pumping bittern, washing Rb with pure water⁺After the adsorption column, the Rb is washed by ammonium salt solution⁺Adsorbing the column, eluting to obtain a first rubidium-rich solution, wherein Rb in the first rubidium-rich solution is⁺The concentration is more than 500 mg/L;

specifically, in step 101, rough filtered brine is pumped into the container filled with Rb at a speed of 0.3-3t/h⁺Adsorption microAdsorption column of the ball, using adsorption microsphere pair Rb⁺Preferential adsorption capacity of (1), Rb of brine⁺Enriched in the adsorption microspheres, and when Rb is at the outlet of the adsorption column⁺Concentration close to that of brine Rb⁺When the concentration is high, the microspheres reach an adsorption saturated state, and the pumping of brine is stopped; washing the residual bittern on the surface of the adsorption microsphere with pure water at the speed of 1.2-2.4t/h, and reacting when the Rb is⁺Stopping washing when the conductivity at the outlet of the adsorption column is lower than 100 mus/cm; then pumping ammonium salt (one of ammonium chloride or ammonium sulfate) solution with concentration of 0.5-4mol/L into the Rb at a speed of 0.3-3t/h⁺Adsorption column using NH⁴⁺And Rb⁺Exchange reaction of (2), adsorption of Rb to the microspheres⁺Eluting when Rb is at the outlet of the adsorption column⁺The concentration is close to Rb in brine⁺When the concentration is higher than the concentration, the desorption process is finished, elution is carried out, and Rb is completed⁺First enrichment to obtain Rb⁺A first rubidium-rich solution with the content higher than 500 mg/L;

when the first rubidium-rich analysis solution is obtained, according to different rubidium content in brine, the series adsorption-series desorption mode may be repeatedly carried out for many times, and the first rubidium-rich analysis solution with qualified concentration is obtained;

the rough filtering equipment is one or more of a quartz sand filter, a plate-and-frame filter press and a belt filter press, and the rough filtering aims at filtering impurities such as crystals, sludge and the like in brine to avoid blocking an adsorption column.

Step 102, concentrating the first rubidium-rich solution to obtain a second rubidium-rich solution, wherein Rb in the second rubidium-rich solution⁺The concentration is 7-9g/L, and the concentration mode can be one or more of distillation modes such as evaporation concentration, membrane separation concentration, membrane distillation concentration and the like;

103, adding aluminum sulfate into the second rubidium-rich solution, and recrystallizing to obtain high-purity rubidium aluminum sulfate crystals; specifically, in step 103, because the second rubidium-rich solution still contains the hetero-ions such as potassium ions and ammonium ions, and compared with the double salts of sulfuric acid such as aluminum potassium sulfate and aluminum ammonium sulfate, the solubility of rubidium aluminum sulfate changes more severely with temperature and has lower solubility at room temperature, the aluminum sulfate is added into the second rubidium-rich solution, heated and dissolved at 70-90 ℃, cooled to room temperature for the first crystallization, and then subjected to solid-liquid separation to obtain crude rubidium aluminum sulfate crystals; re-dissolving and crystallizing the rough rubidium aluminum sulfate crystal, repeating the crystallization step for 2-4 times, and continuously removing potassium, ammonium and other foreign ions in the recrystallization process to finally obtain high-purity rubidium aluminum sulfate crystal; wherein the mass ratio of the aluminum sulfate to the potassium sulfate is 0.35-0.45: 1; in the high-purity aluminum sulfate crystal, the concentration of the impurity ions is lower than 0.01 percent;

the aluminum sulfate and the rubidium sulfate are completely reacted, the aluminum sulfate and the potassium sulfate are reacted according to the mass ratio of 0.35-0.45:1, crude aluminum rubidium sulfate with the purity higher than 87% is obtained through crystallization, high-purity aluminum rubidium sulfate crystals with the purity higher than 99.99% are obtained through recrystallization and purification for 2-4 times, the first impurity removal of a rubidium-rich solution is completed, and the purity of rubidium salt prepared subsequently is guaranteed.

104, adding barium hydroxide into the solution obtained after dissolving the rubidium aluminum sulfate crystals according to the stoichiometric ratio, separating the generated precipitate from the solution to obtain a high-purity rubidium hydroxide solution with the purity of more than 99.9 percent, and finishing the second impurity removal of the rubidium-rich solution;

in the process of preparing the rubidium hydroxide solution, adding the barium hydroxide into the rubidium aluminum sulfate solution, stirring, enabling the pH value of the solution to be in the range of 7.0-7.5, generating white precipitates in the mixed solution, and separating the precipitates after the white precipitates are separated in the solution in a layering way and the pH value of the solution is stabilized in the range of 7.0-7.5; adding phosphoric acid into the clear solution after separation and precipitation, neutralizing until the pH value is 7.0, separating and precipitating to obtain a high-purity rubidium hydroxide solution, and finishing secondary impurity removal of the rubidium-rich solution;

and 105, adding an acid (one of hydrochloric acid, sulfuric acid, nitric acid and carbonic acid) into the rubidium hydroxide solution according to a chemical proportion to obtain a rubidium salt solution, cooling, crystallizing, recrystallizing and purifying to finish third impurity removal, and finally obtaining a high-purity rubidium salt (rubidium chloride, rubidium sulfate, rubidium nitrate and rubidium carbonate) product with the purity of 99-99.99%.

Example 7

A method of extracting rubidium ions from brine and preparing a highly pure rubidium salt, comprising the steps of:

step 101, at a speed of 0.3t/h, the coarsely filtered brine is filled with Rb in example 1⁺Adsorption column for adsorbing microsphere, and method for adsorbing Rb by using adsorption microsphere⁺Preferential adsorption capacity of (1), Rb of brine⁺Enriched in the adsorption microspheres, and when Rb is at the outlet of the adsorption column⁺Concentration close to that of brine Rb⁺When the concentration is high, the microspheres reach an adsorption saturated state, and the pumping of brine is stopped; rinsing the Rb with pure water at a rate of 1.2t/h⁺Brine is remained on the surface of the adsorption column when Rb is used⁺The conductivity at the outlet of the adsorption column reached 100. mu.s/cm, the washing was stopped, and then an ammonium chloride solution having a concentration of 1mol/L was pumped into the Rb at a rate of 3t/h⁺Adsorption column using NH⁴⁺And Rb⁺Exchange reaction of (2), adsorption of Rb to the microspheres⁺Eluting when Rb is at the outlet of the adsorption column⁺The concentration is close to Rb in brine⁺When the concentration is higher than the concentration, the desorption process is finished, elution is carried out, and Rb is completed⁺Enriching for the first time to obtain a first rubidium-rich solution, wherein Rb in the first rubidium-rich analytic solution⁺The concentration is 500 mg/L;

wherein the coarse filtration equipment selects a quartz sand filter;

step 102, evaporating and concentrating the first rubidium-rich analytic solution to obtain a second rubidium-rich solution, wherein Rb in the second rubidium-rich solution⁺The concentration is 7 g/L;

103, adding aluminum sulfate into the second rubidium-rich solution, heating and dissolving at 80 ℃, cooling to 30 ℃ for crystallization, and performing solid-liquid separation to obtain rough rubidium aluminum sulfate crystals with the purity of 80%; re-dissolving and crystallizing the rough rubidium aluminum sulfate crystal, and repeating the crystallizing step for three times to obtain the rubidium aluminum sulfate crystal with the purity of 99.99 percent; wherein the mass ratio of the aluminum sulfate to the potassium sulfate is 0.35: 1; in the high-purity aluminum sulfate crystal, the concentration of the impurity ions is 0.005 percent;

104, adding barium hydroxide into the rubidium aluminum sulfate crystal according to the stoichiometric ratioSeparating the generated precipitate from the solution after dissolution to obtain a rubidium hydroxide solution with the purity of 99.95%; complete Rb⁺Removing impurities for the second time;

105, adding hydrochloric acid into the rubidium hydroxide solution according to the chemical proportion to obtain a rubidium chloride solution, cooling, crystallizing, and purifying by 2-time recrystallization to finish Rb⁺And removing impurities for the third time to finally obtain a rubidium chloride product with the purity of 99.99 percent.

Example 8

step 101, the coarsely filtered brine is filled with Rb in example 2 at a speed of 0.7t/h⁺Adsorption column for adsorbing microsphere, and method for adsorbing Rb by using adsorption microsphere⁺Preferential adsorption capacity of (1), Rb of brine⁺Enriched in the adsorption microspheres, and when Rb is at the outlet of the adsorption column⁺Concentration close to that of brine Rb⁺When the concentration is high, the microspheres reach an adsorption saturated state, and the pumping of brine is stopped; rinsing the Rb with pure water at a rate of 1.8t/h⁺Brine is remained on the surface of the adsorption column when Rb is used⁺The conductivity at the outlet of the adsorption column reached 100. mu.s/cm, the washing was stopped, and then 0.5mol/L ammonium chloride solution was pumped into the Rb at a rate of 0.3t/h⁺Adsorption column using NH⁴⁺And Rb⁺Exchange reaction of (2), adsorption of Rb to the microspheres⁺Eluting when Rb is at the outlet of the adsorption column⁺The concentration is close to Rb in brine⁺When the concentration is higher than the concentration, the desorption process is finished, elution is carried out, and Rb is completed⁺Enriching for the first time to obtain a first rubidium-rich solution, wherein Rb in the first rubidium-rich analytic solution⁺The concentration is 750 mg/L;

wherein, the rough filtration equipment selects a plate-and-frame filter press;

102, performing membrane separation concentration on the first rubidium-rich analysis solution to obtain a second rubidium-rich solution, wherein Rb in the second rubidium-rich solution⁺The concentration is 7.6 g/L;

103, adding aluminum sulfate into the second rubidium-rich solution, heating and dissolving at 70 ℃, cooling to 20 ℃ for crystallization, and performing solid-liquid separation to obtain crude rubidium aluminum sulfate crystals with the purity of 95%; re-dissolving and crystallizing the rough rubidium aluminum sulfate crystal, and repeating the crystallizing step for three times to obtain the rubidium aluminum sulfate crystal with the purity of 99.99 percent; wherein the mass ratio of the aluminum sulfate to the potassium sulfate is 0.40: 1; in the high-purity aluminum sulfate crystal, the concentration of the impurity ions is 0.003 percent;

step 104, adding barium hydroxide into the solution obtained after dissolving the rubidium aluminum sulfate crystals according to the stoichiometric ratio, separating the generated precipitate from the solution to obtain a rubidium hydroxide solution with the purity of 99.93 percent, and finishing the Rb precipitation⁺Removing impurities for the second time;

105, adding sulfuric acid into the rubidium hydroxide solution according to the chemical proportion to obtain a rubidium sulfate solution, cooling, crystallizing, and purifying by 1-time recrystallization to finish Rb⁺And removing impurities for the third time to obtain a rubidium sulfate product with the purity of 99.90 percent.

Example 9

step 101, at a speed of 1.2t/h, the coarsely filtered brine is filled with Rb in example 3⁺Adsorption column for adsorbing microsphere, and method for adsorbing Rb by using adsorption microsphere⁺Preferential adsorption capacity of (1), Rb of brine⁺Enriched in the adsorption microspheres, and when Rb is at the outlet of the adsorption column⁺Concentration close to that of brine Rb⁺When the concentration is high, the microspheres reach an adsorption saturated state, and the pumping of brine is stopped; rinsing the Rb with pure water at a rate of 2.0t/h⁺Brine is remained on the surface of the adsorption column when Rb is used⁺The conductivity at the outlet of the adsorption column was below 100. mu.s/cm, the washing was stopped and then an ammonium chloride solution with a concentration of 1.5mol/L was pumped into the Rb at a rate of 1t/h⁺Adsorption column using NH⁴⁺And Rb⁺Exchange reaction of (2), adsorption of Rb to the microspheres⁺Eluting when Rb is at the outlet of the adsorption column⁺The concentration is close to Rb in brine⁺When the concentration is higher than the concentration, the desorption process is finished, elution is carried out, and Rb is completed⁺Enriching for the first time to obtain a first rubidium-rich solution, wherein Rb in the first rubidium-rich analytic solution⁺At a concentration of880mg/L；

Wherein the rough filtration equipment is a belt filter press;

step 102, performing membrane distillation concentration on the first rubidium-rich analytic solution to obtain a second rubidium-rich solution, wherein Rb in the second rubidium-rich solution⁺The concentration is 8.0 g/L;

103, adding aluminum sulfate into the second rubidium-rich solution, heating and dissolving at 80 ℃, cooling to 35 ℃ for crystallization, and performing solid-liquid separation to obtain rough 87% aluminum rubidium sulfate crystals; re-dissolving and crystallizing the rough rubidium aluminum sulfate crystal, and repeating the crystallization step for four times to obtain the rubidium aluminum sulfate crystal with the purity of 99.99 percent; wherein the mass ratio of the aluminum sulfate to the potassium sulfate is 0.38: 1; in the high-purity aluminum sulfate crystal, the concentration of the impurity ions is 0.009%;

step 104, adding barium hydroxide into the solution obtained after dissolving the rubidium aluminum sulfate crystals according to the stoichiometric ratio, separating the generated precipitate from the solution to obtain a high-purity rubidium hydroxide solution with the purity of 99.95%, and completing Rb⁺Removing impurities for the second time;

105, adding nitric acid into the rubidium hydroxide solution according to the chemical proportion to obtain a rubidium nitrate solution, cooling, crystallizing, and purifying by 2-time recrystallization to finish Rb⁺And removing impurities for the third time to finally obtain a high-purity nitrate product with the purity of 99.95 percent.

Example 10

step 101, at the speed of 2t/h, rough filtered brine is filled with Rb in example 4⁺Adsorption column for adsorbing microsphere, and method for adsorbing Rb by using adsorption microsphere⁺Preferential adsorption capacity of (1), Rb of brine⁺Enriched in the adsorption microspheres, and when Rb is at the outlet of the adsorption column⁺Concentration close to that of brine Rb⁺When the concentration is high, the microspheres reach an adsorption saturated state, and the pumping of brine is stopped; rinsing the Rb with pure water at a rate of 2.4t/h⁺Brine is remained on the surface of the adsorption column when Rb is used⁺The electrical conductivity at the outlet of the adsorption column is lower than 100 mus/cm,the flushing is stopped and then an ammonium sulphate solution with a concentration of 2.5mol/L is pumped into the Rb at a rate of 1.5t/h⁺Adsorption column using NH⁴⁺And Rb⁺Exchange reaction of (2), adsorption of Rb to the microspheres⁺Eluting when Rb is at the outlet of the adsorption column⁺The concentration is close to Rb in brine⁺When the concentration is higher than the concentration, the desorption process is finished, elution is carried out, and Rb is completed⁺Enriching for the first time to obtain a first rubidium-rich solution, wherein Rb in the first rubidium-rich analytic solution⁺The concentration is 900 mg/L;

wherein the coarse filtration equipment selects a quartz sand filter;

step 102, concentrating the first rubidium-rich analytic solution to obtain a second rubidium-rich solution, wherein Rb in the second rubidium-rich solution⁺The concentration is 8.2 g/L;

103, adding aluminum sulfate into the second rubidium-rich solution, heating and dissolving at 85 ℃, cooling to 40 ℃ for crystallization, and performing solid-liquid separation to obtain crude 89% rubidium aluminum sulfate crystals; re-dissolving and crystallizing the rough rubidium aluminum sulfate crystal, and repeating the crystallizing step for 5 times to obtain the rubidium aluminum sulfate crystal with the purity of 99.99 percent; wherein the mass ratio of the aluminum sulfate to the potassium sulfate is 0.41:1, and the concentration of the impurity ions in the high-purity aluminum sulfate crystal is 0.0034%;

104, adding barium hydroxide into the solution obtained after dissolving the rubidium aluminum sulfate crystals according to the stoichiometric ratio, separating the generated precipitate from the solution to obtain a high-purity rubidium hydroxide solution with the purity of 99.97 percent, and finishing the Rb precipitation⁺Removing impurities for the second time;

105, introducing carbon dioxide (carbonic acid) into the rubidium hydroxide solution according to the chemical proportion to obtain a rubidium carbonate solution, cooling, crystallizing, and purifying by 3 times of recrystallization to finish Rb⁺And removing impurities for the third time to finally obtain a high-purity rubidium carbonate product with the purity of 99.99 percent.

Example 11

step 101, filling the rough-filtered brine at the speed of 2.5t/hWith Rb in example 5⁺Adsorption column for adsorbing microsphere, and method for adsorbing Rb by using adsorption microsphere⁺Preferential adsorption capacity of (1), Rb of brine⁺Enriched in the adsorption microspheres, and when Rb is at the outlet of the adsorption column⁺Concentration close to that of brine Rb⁺When the concentration is high, the microspheres reach an adsorption saturated state, and the pumping of brine is stopped; rinsing the Rb with pure water at a rate of 1.6mL/min⁺Brine is remained on the surface of the adsorption column when Rb is used⁺The conductivity at the outlet of the adsorption column was below 100. mu.s/cm, the washing was stopped, and then an ammonium sulfate solution with a concentration of 3mol/L was pumped into the Rb at a rate of 2mL/min⁺Adsorption column using NH⁴⁺And Rb⁺Exchange reaction of (2), adsorption of Rb to the microspheres⁺Eluting when Rb is at the outlet of the adsorption column⁺The concentration is close to Rb in brine⁺When the concentration is higher than the concentration, the desorption process is finished, elution is carried out, and Rb is completed⁺Enriching for the first time to obtain a first rubidium-rich solution, wherein Rb in the first rubidium-rich analytic solution⁺The concentration is 920 mg/L;

wherein the coarse filtration equipment selects a quartz sand filter;

step 102, performing membrane distillation concentration on the first rubidium-rich analytic solution to obtain a second rubidium-rich solution, wherein Rb in the second rubidium-rich solution⁺The concentration is 8.5 g/L;

103, adding aluminum sulfate into the second rubidium-rich solution, heating and dissolving at 90 ℃, cooling to 45 ℃ for crystallization, and performing solid-liquid separation to obtain coarse 90% rubidium aluminum sulfate crystals; re-dissolving and crystallizing the rough rubidium aluminum sulfate crystal, and repeating the crystallizing step for 4 times to obtain the rubidium aluminum sulfate crystal with the purity of 99.99 percent; wherein the mass ratio of the aluminum sulfate to the potassium sulfate is 0.43:1, and the concentration of the impurity ions in the high-purity aluminum sulfate crystal is 0.0032%;

104, adding barium hydroxide into the solution obtained after dissolving the rubidium aluminum sulfate crystals according to the stoichiometric ratio, separating the generated precipitate from the solution to obtain a high-purity rubidium hydroxide solution with the purity of 99.98%, and finishing Rb⁺Removing impurities for the second time;

105, adding hydrochloric acid into the mixture according to the chemical proportionObtaining rubidium salt solution from the rubidium hydroxide solution, cooling and crystallizing to complete Rb⁺And removing impurities for the third time to finally obtain a high-purity rubidium chloride product with the purity of more than 99.9 percent.

Example 12

step 101, at a speed of 3t/h, the coarsely filtered brine is filled with Rb in example 6⁺Adsorption column for adsorbing microsphere, and method for adsorbing Rb by using adsorption microsphere⁺Preferential adsorption capacity of (1), Rb of brine⁺Enriched in the adsorption microspheres, and when Rb is at the outlet of the adsorption column⁺Concentration close to that of brine Rb⁺When the concentration is high, the microspheres reach an adsorption saturated state, and the pumping of brine is stopped; rinsing the Rb with pure water at a rate of 2.4t/h⁺Brine is remained on the surface of the adsorption column when Rb is used⁺The conductivity at the outlet of the adsorption column reached 100 μm/cm, the washing was stopped, and then an ammonium sulfate solution having a concentration of 4mol/L was pumped into the Rb at a rate of 3t/h⁺Adsorption column using NH⁴⁺And Rb⁺Exchange reaction of (2), adsorption of Rb to the microspheres⁺Eluting when Rb is at the outlet of the adsorption column⁺The concentration is close to Rb in brine⁺When the concentration is higher than the concentration, the desorption process is finished, elution is carried out, and Rb is completed⁺Enriching for the first time to obtain a first rubidium-rich solution, wherein Rb in the first rubidium-rich analytic solution⁺The concentration is 1 g/L;

wherein, the rough filtration equipment selects a plate-and-frame filter press;

102, performing membrane separation concentration on the first rubidium-rich analysis solution to obtain a second rubidium-rich solution, wherein Rb in the second rubidium-rich solution⁺The concentration is 9 g/L;

103, adding aluminum sulfate into the second rubidium-rich solution, heating and dissolving at 80 ℃, cooling to 30 ℃ for crystallization, and performing solid-liquid separation to obtain crude 91% rubidium aluminum sulfate crystals; re-dissolving and crystallizing the rough rubidium aluminum sulfate crystal, and repeating the crystallizing step for 5 times to obtain high-purity rubidium aluminum sulfate crystal; wherein the mass ratio of the aluminum sulfate to the potassium sulfate is 0.45:1, and the concentration of the impurity ions in the high-purity aluminum sulfate crystal is lower than 0.002%;

104, adding barium hydroxide into the solution obtained after dissolving the rubidium aluminum sulfate crystals according to the stoichiometric ratio, separating the generated precipitate from the solution to obtain a high-purity rubidium hydroxide solution with the purity of 99.96%, and finishing Rb⁺Removing impurities for the second time;

105, adding sulfuric acid into the rubidium hydroxide solution according to the chemical proportion to obtain a rubidium salt solution, cooling, crystallizing, and purifying by 3 times of recrystallization to finish Rb⁺And removing impurities for the third time to finally obtain a high-purity rubidium sulfate product with the purity of more than 99.99 percent.

In conclusion, the invention prepares low-concentration rubidium ions into various rubidium salts with the purity of 99.99% by closely matching secondary enrichment and tertiary impurity removal on low-concentration brine containing rubidium or ore leachate containing rubidium, the progress is not easily achieved by technical personnel in the field, the technical problem in the field is broken through, the preparation process is environment-friendly and pollution-free, and the remarkable beneficial effect is achieved.

While embodiments of the invention have been disclosed above, it is not limited to the applications listed in the description and the embodiments, which are applicable to all kinds of fields suitable for the invention, and further modifications can be easily made by those skilled in the art, so that the invention is not limited to the specific details and the examples shown herein without departing from the general concept defined by the claims and the equivalent scope.

Claims

1. Extraction of Rb from low-concentration brine⁺And a method for producing a highly pure rubidium salt, comprising the steps of:

passing the coarsely filtered bittern through Rb⁺Adsorbing with adsorption column, stopping pumping bittern, washing Rb with pure water⁺Adsorption column, which is subsequently washed with ammonium salt solution for Rb⁺Eluting to obtain a first rubidium-rich solution; wherein, said Rb⁺The adsorption column is filled with Rb⁺Adsorption column for adsorbing microspheres, Rb⁺The adsorption microspheres comprise the following massThe raw materials in percentage are as follows:

6-14% of polyvinyl alcohol, 0.4-1.5% of sodium alginate, 0.4-1.5% of sodium silicate, 20-60% of rubidium ion exchange material and 30-60% of water;

2. The method of claim 1, wherein the Rb is extracted from low-concentration brine⁺And a method for producing a highly pure rubidium salt, characterized in that Rb is mentioned⁺The adsorption column is filled with Rb⁺Adsorption column for adsorbing microspheres, Rb⁺The adsorption microspheres comprise the following raw materials in percentage by mass:

3. The method of claim 1, wherein the Rb is extracted from low-concentration brine⁺And a method for preparing a rubidium salt having high purity, wherein the rubidium ion exchange material is one or more of heteropolyacid salts having a Keggin structure, and the general structural formula of the heteropolyacid salts is [ XM₁₂O₄₀]^n-Wherein, X is P, Si, Ge, As, and M is Mo, W.

4. The method of claim 1, wherein the Rb is extracted from low-concentration brine⁺And a method for preparing a highly pure rubidium salt, characterized in that the brine is a natural rubidium-containing brine or a leachate of a rubidium-containing ore, and Rb in the brine⁺The content is more than or equal to 40 mg/L.

5. The method of claim 1, wherein the Rb is extracted from low-concentration brine⁺And a process for producing a highly pure rubidium salt, characterized in that the brine after rough filtration is passed through Rb⁺Adsorbing with adsorption column, stopping pumping bittern, washing Rb with pure water⁺After the adsorption column, the Rb is washed by ammonium salt solution⁺And (3) adsorbing the column, and eluting to obtain a first rubidium-rich solution, wherein the first rubidium-rich solution specifically comprises:

passing ammonium salt solution through the Rb at a rate of 0.3-3t/h⁺Adsorption column, at the outlet Rb of adsorption column⁺The concentration is close to Rb in the original brine⁺And when the concentration is high, ending the desorption process, and eluting to obtain the first rubidium-rich solution.

6. The method of claim 1, wherein the Rb is extracted from low-concentration brine⁺And a method for producing a highly pure rubidium salt, characterized in that the ammonium salt is one of ammonium chloride and ammonium sulfate, and the NH is⁴⁺The concentration is 0.5-4 mol/L.

7. The method of claim 1, wherein the Rb is extracted from low-concentration brine⁺And a method for producing a rubidium salt, characterized in that Rb in said first rubidium-rich solution⁺Rb in the second rubidium-rich solution with the concentration of more than 500mg/L⁺The concentration is 7-9 g/L.

8. The method of claim 1, wherein the Rb is extracted from low-concentration brine⁺And a method for preparing a high-purity rubidium salt, which is characterized in that aluminum sulfate is added into the second rubidium-enriched solution, and recrystallization is performed to obtain a high-purity rubidium aluminum sulfate crystal specifically comprising:

9. The method of claim 1, wherein the Rb is extracted from low-concentration brine⁺And a method for producing a rubidium salt having high purity, characterized in that an acid added to the rubidium hydroxide solution is selected from one of hydrochloric acid, sulfuric acid, nitric acid and carbonic acid.