A method for obtaining a high-content rubidium and / or cesium solution from salt lake sediments based on leaching

Abstract

The present invention discloses a method for obtaining a high-content rubidium and / or cesium solution from salt lake sediments based on leaching, comprising the following steps: step 1, draining the pore water in the salt lake sediments and the brine contained in the salt lake sediments to obtain the salt lake sediments after filtration; step 2, putting the filtered sediments obtained in step 1 into fresh water for mixing and stirring, washing out the soluble ions in the sediments that interfere with the subsequent cesium extraction, and then filtering to obtain sediments; step 3, using ammonium chloride solution to leach the sediments obtained in step 2, after the sediments and the ammonium chloride solution are fully reacted, solid-liquid separation is performed to obtain a high-content cesium solution. The process of obtaining a high-content cesium solution of the present invention has a high degree of automation, simple operation, low solid waste discharge, and is green and environmentally friendly. The cesium content in the obtained high-content cesium solution is much higher than the cesium content in natural brine, and the potassium, sodium, calcium, magnesium and other ions are significantly lower than natural brine, which is conducive to the subsequent extraction of cesium.

Description

Technical Field

[0001] The invention relates to the technical field of rare alkali metals, and in particular to a method for obtaining a solution with high rubidium and / or cesium content from salt lake sediments based on leaching. Background Art

[0002] At present, there are four main technologies for extracting and separating rubidium: the first is the fractional crystallization method, which uses the principle of fractional crystallization based on the difference in solubility of substances in the solution to separate and purify substances. For example, rubidium and its compounds are extracted from rubidium-containing minerals such as lepidolite or cesium garnet. However, as a traditional method, it is rarely used in modern industrial production. The second is the precipitation method. Rubidium ions can react with certain anions to produce precipitation. By controlling the precipitation conditions, such as concentration and acidity, rubidium and other impurities can be effectively separated to achieve the purpose of recovering rubidium and rubidium salts. This method can be used for further purification of crude products. Since the rubidium content in salt lake brine is low, precipitation is rarely used to extract rubidium from brine. Due to the high price of precipitants and the general stability of precipitates, this method is not widely used in the industry. The third is the ion exchange method, which is an important means of extracting rubidium from liquid resources such as brine. Ion exchangers (ion screening materials) are used to extract rubidium from brine. A method of separation based on the difference in ion exchange capacity between the exchangeable groups in the ions and the various ions in the solution. This method has the advantages of simple process, high recovery rate, and easy large-scale industrial production, and is a very promising method; the fourth is the solvent extraction method, which mixes the organic extract and the water-soluble rubidium-cesium mother liquor with each other and separates the two by utilizing the difference in mass and density. This method can be used for the extraction and recovery of rubidium from rubidium-containing minerals, as well as for the extraction and recovery of rubidium from rubidium-containing brines. It is the most widely used, most studied, and fastest-progressing separation and recovery technology in recent years, and has broad application prospects.

[0003] Whether solvent extraction, precipitation or ion exchange, solutions with high rubidium and / or cesium concentrations are required. Currently, research on the extraction of rubidium and / or cesium from natural brine mainly focuses on natural brine extraction and precipitation extraction of cesium. Since the rubidium and / or cesium content in natural brine is low, the extraction efficiency of rubidium and / or cesium is low. The present invention not only provides a new resource for the extraction of cesium, but also provides a high rubidium and / or cesium content solution for the separation and extraction of rubidium and / or cesium, thereby improving the extraction efficiency.

[0004] The present invention aims at the disadvantages of the current extraction method for directly extracting rubidium and / or cesium from natural brine containing cesium, such as low rubidium and / or cesium content in natural brine and poor extraction efficiency. The present invention selects sediments from a salt lake containing rubidium and / or cesium, and obtains a solution with a high cesium content through three-step treatment. The solution with a high rubidium and / or cesium content is beneficial to the subsequent extraction of rubidium and / or cesium. Summary of the invention

[0005] The purpose of the present invention is to provide a method for obtaining a high-content rubidium and / or cesium solution from salt lake sediments based on leaching in order to address the technical defects in the prior art.

[0006] The technical solution adopted to achieve the purpose of the present invention is:

[0007] A method for obtaining a high-rubidium and / or cesium solution from salt lake sediments based on leaching, comprising the following steps:

[0008] Step 1, draining the pore water in the salt lake sediment containing rubidium and / or cesium and the brine contained in the salt lake sediment to obtain the filtered and dried salt lake sediment;

[0009] Step 2, placing the filtered sediment obtained in step 1 into fresh water for mixing and stirring to wash out soluble ions (such as sodium, potassium, calcium, magnesium, sulfate, etc.) in the sediment that may interfere with the subsequent extraction of rubidium and / or cesium, and then filtering or freeze-drying to obtain sediment;

[0010] Step 3, using ammonium chloride solution to leaching the sediment obtained in step 2, after the sediment and the ammonium chloride solution are fully reacted, solid-liquid separation is performed to obtain a solution with high rubidium and / or cesium content.

[0011] In the above technical solution, in step 1, the salt lake sediments containing rubidium and / or cesium are mined from the salt lake by an excavator or a dredging ship.

[0012] In the above technical solution, in step 1, a vertical filter press is used to discharge the pore water in the salt lake sediment and the brine contained in the salt lake sediment.

[0013] In the above technical solution, in step 2, the filtered sediment obtained in step 1 and fresh water are placed in a stirred reactor for mixing and stirring, so that the filtered sediment obtained in step 1 and fresh water are fully mixed and washed.

[0014] In the above technical solution, in step 2, during mixing and stirring, the liquid-to-solid ratio is 1:0.5~1:2, that is, the mass of fresh water and the filtered sediment obtained in step 1 is 1:0.5~1:2, and the stirring speed is 50~100 rpm.

[0015] In the above technical solution, in step 2, when filtering and drying, a belt filter press is used for filtering and when freeze-drying, a freeze dryer is used for freeze-drying.

[0016] In the above technical solution, in step 3, the concentration of the ammonium chloride solution is 0.5-2.0 mol / L, and the preferred concentration of the ammonium chloride solution is 1.0 mol / L.

[0017] In the above technical solution, in step 3, leaching is carried out in a stirred reactor with a stirring speed of 50 to 200 rpm.

[0018] In the above technical scheme, in step 3, during leaching, the liquid-to-solid ratio is 1:0.5~1:4, that is, the mass ratio of the ammonium chloride solution to the mass ratio of the sediment obtained in step 2 is 1:0.5~1:4, and the preferred liquid-to-solid ratio is 1:1. In step 3, the leaching time is 0.5~1 hour, and the leaching temperature is 40-80°C.

[0019] In the above technical solution, in step 3, the cesium content in the high rubidium and / or cesium content solution is 15-35 mg / L, and the rubidium content is 10-19 mg / L.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] 1. The traditional method of extracting rubidium and / or cesium is to grind, leaching, purify and extract cesium-containing solid minerals, which has a complex process and a large amount of solid waste emissions. Alternatively, rubidium and / or cesium are directly separated and extracted from natural salt lake brine. Since the cesium content of natural brine is low, the operation is complicated. The extraction efficiency is low. The method provided by the present invention is to obtain a high-rubidium and / or cesium solution from rubidium and / or cesium salt lake sediments. The salt lake sediments do not need to be ground. They only need to be subjected to simple physical treatment and then leached with a certain concentration of ammonium chloride solution to obtain a high-rubidium and / or cesium solution, providing high-quality raw materials for the subsequent extraction of rubidium and / or cesium. The process of obtaining a high-rubidium and / or cesium solution in the present invention has a high degree of automation, simple operation, low solid waste emissions, and is green and environmentally friendly.

[0022] 2. The present invention takes out the surface sediment of the salt lake containing rubidium and / or cesium and filters it through a vertical filter press to remove most of the impurity ions such as potassium, sodium, calcium, and magnesium that affect the separation and extraction of rubidium and / or cesium. Then, by controlling the liquid-solid ratio, the sediment after filtering is washed with water in a stirred reactor to further remove the impurity ions in the sediment that affect subsequent extraction or precipitation. Then, a certain concentration of ammonium chloride solution is used to leaching the cesium ions in the sediment to obtain a high rubidium and / or cesium content solution, wherein the rubidium and / or cesium content is much higher than the rubidium and / or cesium content in natural brine, and the potassium, sodium, calcium, magnesium and other ions are significantly lower than those in natural brine, which is very beneficial to the subsequent separation and extraction processes such as extraction or precipitation of rubidium and / or cesium. DETAILED DESCRIPTION

[0023] The present invention is further described in detail below in conjunction with specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0024] We conducted relevant experimental research using Lago Co Salt Lake as an example. The cesium content in the natural brine of Lago Co was tested to be 9.6 mg / L, and the average rubidium content was 6.8 mg / L. The total cesium content in its salt lake sediments was tested to be 182 mg / L, and the average rubidium content was 30 mg / L. The content of rubidium and cesium in the salt lake sediments was much higher than that in natural brine. We conducted a laboratory leaching experiment using the Lago Co Salt Lake sediments as an example.

[0025] The following is a table of the main components of Laguocuo brine:

[0026] .

[0027] Example 1

[0028] A method for obtaining a high-cesium solution from salt lake sediments comprises the following steps:

[0029] Step 1, taking 20 grams of salt lake sediments from Laguocuo Salt Lake, filtering out water using a filter press to obtain 10 grams of filtered sediments;

[0030] Step 2, directly placing the filtered sediment into a fully automatic stirred reactor pre-filled with fresh water, with a liquid-to-solid ratio of 1:0.5, and a stirring speed of 50 rpm, fully stirring and washing the residual potassium, sodium, calcium, magnesium and other ions in the sediment, and filtering the sediment to dry the water for later use;

[0031] Step 3, adding the sediment dried from step 2 and 0.5 mol / L ammonium chloride solution into a stirred reactor at a liquid-to-solid ratio of 1:0.5 for leaching, the stirring speed is 100 rpm, the temperature is controlled at 40° C., the leaching time is 0.5 hour, and then solid-liquid separation is performed to obtain a high-cesium-containing solution, wherein the cesium ion content of the high-cesium-containing solution is 20 mg / L.

[0032] ;

[0033] The untreated ion contents in the table refer to the ion contents in the cesium and / or rubidium-containing sediments before treatment, and the ion contents after treatment refer to the ion contents in the high cesium and / or rubidium-containing solutions after treatment according to the methods of the corresponding embodiments. This is true for the following embodiments.

[0034] Example 2

[0035] A method for obtaining a high-rubidium solution from salt lake sediments comprises the following steps:

[0036] Step 1, taking 20 grams of sediment from Laguocuo Salt Lake, removing water using a freeze dryer to obtain 10 grams of freeze-dried sediment;

[0037] Step 2, directly placing the filtered sediment into a fully automatic stirred reactor pre-filled with fresh water, with a liquid-to-solid ratio of 1:1 in the stirred reactor, with a stirring speed of 50 rpm, fully stirring and washing the residual potassium, sodium, calcium, magnesium and other ions in the sediment, and filtering the sediment to dry the water for later use;

[0038] Step 3, the sediment filtered out of water in step 2 is mixed with 1 mol / L ammonium chloride at a liquid-to-solid ratio of 1:0.5, the stirring speed is 100 rpm, the temperature is controlled at 40°C, the leaching time is 0.5 hours, and then the solid-liquid separation is performed to obtain a high rubidium content solution, and the final rubidium ion content in the high rubidium content solution is 15 mg / L.

[0039] .

[0040] Example 3

[0041] A method for obtaining a solution high in rubidium and cesium from salt lake sediments comprises the following steps:

[0042] Step 1, taking 20 grams of sediment from Laguocuo Salt Lake, filtering out water using a filter press to obtain 10 grams of filtered sediment;

[0043] Step 2, directly placing the filtered sediment into a fully automatic stirred reactor pre-filled with fresh water, with a liquid-to-solid ratio of 1:1 and a stirring speed of 100 rpm, fully stirring and washing the residual potassium, sodium, calcium, magnesium and other ions in the sediment, and filtering the sediment to dry the water for later use;

[0044] Step 3, adding the sediment dried from step 2 and 1.0 mol / L ammonium chloride in a stirred reactor at a liquid-to-solid ratio of 1:1 for leaching, the stirring speed is 100 rpm, the temperature is controlled at 50° C., the leaching time is 1 hour, and then solid-liquid separation is performed to obtain a high-cesium-containing solution, wherein the cesium ion content of the high-rubidium and / or cesium-containing solution is 35 mg / L, and the rubidium ion content is 19 mg / L.

[0045] .

[0046] Example 4

[0047] A method for obtaining a solution high in rubidium and cesium from salt lake sediments comprises the following steps:

[0048] Step 1, taking 20 grams of sediment containing rubidium and cesium from Laguocuo Salt Lake, filtering out water using a filter press to obtain 10 grams of filtered sediment;

[0049] Step 2, directly placing the filtered sediment into a fully automatic stirred reactor pre-filled with fresh water, with a liquid-to-solid ratio of 1:2 and a stirring speed of 100 rpm, fully stirring and washing the residual potassium, sodium, calcium, magnesium and other ions in the sediment, and filtering the sediment to dry the water for later use;

[0050] Step 3, adding the sediment dried in step 2 and 2.0 mol / L ammonium chloride in a stirred reactor at a liquid-to-solid ratio of 1:2 for leaching, the stirring speed is 200 rpm, the temperature is controlled at 60° C., the leaching time is 1 hour, and then solid-liquid separation is performed to obtain a high-cesium-containing solution, wherein the cesium ion content of the high-rubidium and / or cesium-containing solution is 32 mg / L, and the rubidium ion content is 10 mg / L.

[0051] .

[0052] Example 5

[0053] A method for obtaining a high-cesium solution from salt lake sediments comprises the following steps:

[0054] Step 1, taking 20 grams of sediment from Laguocuo Salt Lake, filtering out water using a filter press to obtain 10 grams of filtered sediment;

[0055] Step 2, directly placing the filtered sediment into a fully automatic stirred reactor pre-filled with fresh water, with a liquid-to-solid ratio of 1:2 and a stirring speed of 100 rpm, fully stirring and washing the residual potassium, sodium, calcium, magnesium and other ions in the sediment, and filtering the sediment to dry the water for later use;

[0056] Step 3, adding the sediment dried in step 2 and 2.0 mol / L ammonium chloride in a liquid-to-solid ratio of 1:4 into a stirred reactor for leaching, the stirring speed is 200 rpm, the temperature is controlled at 80° C., the leaching time is 1 hour, and then the solid-liquid separation is performed to obtain a high-cesium-containing solution, wherein the cesium ion content in the high-cesium-containing solution is 15 mg / L.

[0057] .

[0058] Example 6

[0059] A method for obtaining a high-rubidium solution from salt lake sediments comprises the following steps:

[0060] Step 1, taking 20 grams of sediment from Laguocuo Salt Lake, removing water using a freeze dryer to obtain 10 grams of filtered sediment;

[0061] Step 2, directly placing the filtered sediment into a fully automatic stirred reactor pre-filled with fresh water, with a liquid-to-solid ratio of 1:1 and a stirring speed of 100 rpm, fully stirring and washing the residual potassium, sodium, calcium, magnesium and other ions in the sediment, and filtering the sediment to dry the water for later use;

[0062] Step 3, the sediment filtered out in step 2 is mixed with 1.0 mol / L ammonium chloride at a liquid-to-solid ratio of 1:2, the stirring speed is 200 rpm, the temperature is controlled at 80° C., the leaching time is 1 hour, and the final rubidium ion content in the leaching solution is 12 mg / L.

[0063] .

[0064] The above is only a preferred embodiment of the present invention. It should be pointed out that, for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for obtaining a high-content rubidium and / or cesium solution from salt lake sediments based on leaching, characterized in that: The following steps are involved: Step 1, extracting rubidium and / or cesium salt lake surface sediments from the salt lake using an excavator or a dredging ship, filtering the rubidium and / or cesium salt lake surface sediments through a vertical filter press, and discharging pore water in the rubidium and / or cesium salt lake surface sediments and brine in the salt lake sediments to obtain filtered salt lake sediments; Step 2, placing the filtered sediment obtained in step 1 into fresh water for mixing and stirring to wash out soluble ions in the sediment that interfere with the subsequent separation and extraction of rubidium and / or cesium, and then filtering or freeze-drying to obtain sediment; Step 3, using an ammonium chloride solution to leaching the sediment obtained in step 2, and after the sediment and the ammonium chloride solution are fully reacted, performing solid-liquid separation to obtain a solution with a high content of rubidium and / or cesium; The concentration of ammonium chloride solution is 0.5-2.0 mol / L. During leaching, the liquid-to-solid ratio is 1:0.5-1:4, the leaching time is 0.5-1 hour, and the leaching temperature is 40-80°C.

2. The method for obtaining a high-content rubidium and / or cesium solution from salt lake sediments based on leaching according to claim 1, characterized in that: In the step 2, the filtered sediment obtained in step 1 and fresh water are placed in a stirred reactor for mixing and stirring, so that the filtered sediment obtained in step 1 and fresh water are fully mixed and washed.

3. The method for obtaining a high-content rubidium and / or cesium solution from salt lake sediments based on leaching according to claim 1, characterized in that: In the step 2, during mixing and stirring, the liquid-to-solid ratio is 1:0.5-1:2, and the stirring speed is 50-100 rpm.

4. The method for obtaining a high-content rubidium and / or cesium solution from salt lake sediments based on leaching according to claim 1, characterized in that: In the step 2, when filtering and drying, a belt filter press is used for filtering and when freeze-drying, a freeze dryer is used for freeze-drying.

5. The method for obtaining a high-content rubidium and / or cesium solution from salt lake sediments based on leaching according to claim 1, characterized in that: In the step 3, leaching is performed in a stirred reactor.

6. The method for obtaining a high-content rubidium and / or cesium solution from salt lake sediments based on leaching according to claim 1, characterized in that: In step 3, the cesium content of the high rubidium and / or cesium content solution is 15-35 mg / L, and the rubidium content is 10-19 mg / L.

7. The method for obtaining a high-content rubidium and / or cesium solution from salt lake sediments based on leaching according to claim 1, characterized in that: In the step 3, the concentration of the ammonium chloride solution is 1.0 mol / L.

8. The method for obtaining a high-content rubidium and / or cesium solution from salt lake sediments based on leaching according to claim 1, characterized in that: In step 3, the liquid-to-solid ratio is 1:1.