Method for extracting rubidium from fly ash lixivium and lithium ore waste residues

Abstract

The invention discloses a method for extracting rubidium from fly ash lixivium and lithium ore waste residues, which comprises the following steps: performing particle size control and homogenization on the lithium ore waste residues by crushing to obtain pretreated lithium ore waste residue powder; performing chlorine concentration control on the fly ash washing leachate through water evaporation to obtain a chlorinating agent; a chlorinating agent, the pretreated lithium ore waste residues and a neutralizing reagent are fully mixed to be subjected to balling and drying, and dried green balls are obtained; the dried green pellets are subjected to a chloridizing roasting process, and a roasted material is obtained after the reaction is completed; and the roasted material is subjected to water leaching in a certain environment, and a rubidium enrichment solution and leaching residues are obtained through solid-liquid separation of leachate. According to the method, the fly ash lixivium can be used as a chlorinating agent to cooperate with the lithium ore waste residues for chloridizing roasting, the rubidium extraction efficiency of the lithium ore waste residues can be improved, and meanwhile the fly ash lixivium treatment cost and the chloridizing roasting cost are reduced.

Description

Technical Field

[0001] The invention relates to the field of comprehensive utilization of lithium mine waste residue and waste incineration fly ash, and in particular to a method for extracting rubidium from fly ash leaching solution in coordination with lithium mine waste residue. Background Art

[0002] Rubidium is an alkali metal element that provides key material support in high-tech fields and is widely used in the fields of global positioning system (GPS), communication networks, astrophysics, etc. Because the transition frequency of rubidium atoms is very stable, it can be used as an accurate frequency standard, which is essential to ensure the accuracy of communication and navigation systems. However, minerals enriched with rubidium are very rare, and its content is very low in nature, averaging only about 0.001%, so it is called one of the representatives of "rare metals". Usually, rubidium exists in nature mainly in the form of salt mines, salt lake brines or iron lithium mica. Secondly, rubidium often exists in the same mineral with potassium, and does not form rubidium minerals alone.

[0003] Lithium mine waste contains high-value elements such as potassium, lithium, rubidium, cesium, and beryllium. These elements usually exist in the form of mineral associations. Using the different forms and properties of each element and selecting the appropriate process to separate and purify the target elements is an effective way to increase the resource value of waste. Due to the complex components of lithium mine waste and the similar properties of some metal elements, multiple steps and a combination of technologies are required to achieve the best extraction effect. Therefore, the extraction of rubidium from lithium mine waste has the characteristics of high selectivity, multiple steps and technical combinations, environmental protection and economy.

[0004] Chlorination roasting has a synergistic effect in the process of extracting metal elements from industrial solid waste. Rubidium and other elements in the raw materials are digested to form soluble sulfates. Rubidium can be recovered by crystallization after roasting and leaching. Chinese invention patent CN114107674B provides a method for volatilizing rubidium from spodumene tailings based on microwave fields. By recovering rare and scattered metals such as rubidium from high-temperature materials such as rubidium-containing smoke, the comprehensive utilization efficiency of elements such as rubidium, lithium, silicon, aluminum, potassium, and sodium in spodumene tailings is improved, and the process flow gives full play to the advantages of endogenous heating, energy saving and environmental protection. However, the current extraction efficiency of rubidium, especially the efficiency of extracting rubidium from lithium ore or lithium ore waste, is still not ideal. Summary of the invention

[0005] In view of the defects and shortcomings of the above-mentioned prior art, the present invention provides a method for extracting rubidium by using fly ash leaching solution in conjunction with lithium mine waste slag. The fly ash leaching solution is used as a chlorinating agent, which can not only effectively treat fly ash dechlorination wastewater, but also improve the extraction efficiency of rubidium in lithium mine waste slag, that is, it can realize the resource utilization of fly ash dechlorination wastewater while synergistically improving the enrichment and recovery of rubidium elements in lithium mine waste slag, providing a new idea for the comprehensive utilization of rubidium resources in lithium mine waste slag and fly ash dechlorination wastewater.

[0006] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0007] A method for extracting rubidium by using fly ash leaching solution in conjunction with lithium ore waste residue comprises the following steps:

[0008] S1. Select lithium ore waste and crush it into a particle size range of 0 to 100 μm to obtain lithium ore waste powder;

[0009] S2. Selecting fly ash for water washing and dechlorination, and then controlling the chlorine concentration of the fly ash leachate to 200-800 g / L by evaporation of water to obtain a chlorinating agent;

[0010] S3. The chlorinating agent obtained in S2, the lithium ore waste powder obtained in S1 and the neutralizing agent are fully mixed into balls, and then dried to obtain dry green balls;

[0011] S4. The dried green pellets obtained in S3 are heated to 600-1000°C and calcined for 1-3 hours to obtain a calcined material;

[0012] S5. The roasted material obtained in S4 is taken out for water leaching, and the leaching liquid is separated into rubidium-enriched liquid and leaching residue by solid-liquid separation.

[0013] Furthermore, in step S1, the particle size range of the lithium ore waste slag powder is 0-100 μm, reaching more than 98%, and more preferably more than 90% of the particle size range is 0-75 μm.

[0014] Furthermore, in step S2, the chlorine content in the fly ash is not less than 200 mg / g.

[0015] Furthermore, in step S2, the chlorine concentration of the chlorinating agent is preferably 600-700 g / L.

[0016] Furthermore, in step S2, in the water washing dechlorination, the solid-liquid mass ratio of fly ash to water is 1:3-5, the stirring speed is 300-600 r / min, the water washing temperature is 30-50° C., and the dechlorination time is 30-60 min.

[0017] Furthermore, in step S3, the mass ratio of the chlorinating agent, the lithium ore waste powder and the neutralizing agent is 3 to 7:10:2, preferably 6 to 7:10:2.

[0018] Furthermore, in step S3, the neutralizing agent is sodium carbonate; the drying temperature is 70 to 105° C., and the drying time is 12 to 24 hours.

[0019] Furthermore, in step S3, the moisture content of the pellets before drying is controlled at 5-20%, and the particle size of the pellets is controlled at 17-34 mm.

[0020] Furthermore, in step S5, the water immersion temperature of the roasted material is 20-25° C. (normal temperature is acceptable), and the leaching time is 0.5-2 h.

[0021] Furthermore, in step S5, the particle size of the roasting material is controlled to be 20-30 mm, and the mass ratio of the roasting material to water is 1:3-6 (preferably 1:4).

[0022] The beneficial effects of the present invention are:

[0023] The present invention can use fly ash leaching solution as a chlorinating agent to cooperate with lithium ore waste slag for chlorination roasting, which can not only improve the rubidium extraction efficiency of lithium ore waste slag, but also reduce the cost of treating fly ash leaching solution and chlorination roasting. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a process flow chart of the present invention.

[0025] Figure 2 It is the XRD diagram of the original ore (taken from the lithium ore waste rock tailings in S1), the roasted sample (taken from the roasted material obtained in S4) and the leached sample (taken from the rubidium enriched solution obtained in S5) of Example 2 of the present invention.

[0026] Figure 3 These are SEM and EDS images of the original ore and roasted sample of Example 2 of the present invention, wherein (a) is the original ore and (b) is the roasted sample. DETAILED DESCRIPTION

[0027] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments, but the protection scope of the present invention is not limited thereby.

[0028] In the following examples, unless otherwise specified, the raw materials and instruments used are commercially available, the equipment used is conventional equipment, and the data obtained are the average values ​​of more than three repeated experiments.

[0029] Example 1

[0030] A method for extracting rubidium from fly ash leaching solution in cooperation with lithium ore waste residue, the process flow is as follows Figure 1 As shown, the following steps are included:

[0031] S1. Take 10g of lithium ore waste rock tailings, dry, crush and sieve to obtain lithium ore waste slag powder with a particle size range of 0-100μm exceeding 98%. The lithium ore tailings used in this embodiment have an Fe content of 3.6wt%, an Al content of 20.7wt%, a Si content of 62.4wt% and a Ca content of 4.3wt%.

[0032] S2. Take 50g of fly ash and wash and dechlorinate it with water at a liquid-to-solid ratio of 4:1, a stirring speed of 500r / min, and a water washing temperature of 40°C. After 1h, the suspension is filtered to separate the solid and liquid. The chlorine concentration of the fly ash leachate is controlled at 500g / L by evaporation of water to obtain a chlorinating agent.

[0033] S3. After fully mixing the chlorinating agent, lithium ore waste powder and neutralizing agent sodium carbonate, they are mixed into balls in a mass ratio of 5:10:2 (10 ml of chlorinating agent, 10 g of lithium ore waste powder, 2 g of sodium carbonate). The drying environment temperature is set to 105°C and the drying time is 24 hours to obtain dry green balls.

[0034] S4, heating the dried green balls to 900° C. and calcining for 2 hours to obtain calcined materials.

[0035] S5, taking out the calcined material and grinding it into powder using a ceramic mortar, and subjecting it to a water leaching process at a leaching temperature of 25° C. and a leaching time of 1 h, and obtaining a rubidium-enriched solution and a leaching residue through solid-liquid separation of the leaching liquid.

[0036] The rubidium ion concentration in the rubidium enriched solution was measured by atomic absorption spectrophotometer. The specific amount of raw material ratio is shown in Table 1, and the basic data of the leaching solution is shown in Table 2.

[0037] The results showed that under these conditions, the rubidium concentration in the rubidium-enriched solution was 273.92 mg / L and the rubidium extraction rate was 87.48%.

[0038] Example 2

[0039] A method for extracting rubidium from fly ash leaching solution in cooperation with lithium ore waste residue, the process flow is as follows Figure 1 As shown, the following steps are included:

[0040] S1. Take 10g of lithium ore waste rock tailings, dry, crush and sieve to obtain lithium ore waste slag powder with a particle size range of 0-100μm exceeding 98%. The lithium ore tailings used in this embodiment have an Fe content of 3.6wt%, an Al content of 20.7wt%, a Si content of 62.4wt% and a Ca content of 4.3wt%.

[0041] S2. Take 50g of fly ash and wash and dechlorinate it according to the conditions of liquid-to-solid ratio of 4:1, stirring speed of 500r / min, and water washing temperature of 40℃. After 1h, the suspension is filtered to separate the solid and liquid. The chlorine concentration of the washing leachate is controlled at 600g / L by evaporation of water to obtain a chlorinating agent.

[0042] S3. The chlorinating agent, lithium ore waste powder and neutralizing agent sodium carbonate are fully mixed and mixed into balls in a mass ratio of 6:10:2. The drying environment temperature is set to 105° C. and the drying time is 24 hours to obtain dry green balls.

[0043] S4, heating the dried green balls to 900° C. and calcining for 2 hours to obtain calcined materials.

[0044] S5, taking out the calcined material and grinding it into powder using a ceramic mortar, and subjecting it to a water leaching process at a leaching temperature of 25° C. and a leaching time of 1 h, and obtaining a rubidium-enriched solution and a leaching residue through solid-liquid separation of the leaching liquid.

[0045] The rubidium ion concentration in the rubidium enriched solution was measured by atomic absorption spectrophotometer. The specific amount of raw material ratio is shown in Table 1, and the basic data of the leaching solution is shown in Table 2.

[0046] The results show that under this condition, the rubidium concentration in the rubidium enriched solution is 278.98 mg / L and the rubidium extraction rate is 90.02%. Figure 3 (a) It can be seen that sodium, potassium and chlorine are evenly distributed in lithium ore tailings, and the distribution range of rubidium and silicon is the same, that is, rubidium in the original ore exists in silicon-containing minerals. Figure 3 (b) The calcined sample shows that the element distribution range of chlorine and rubidium is the same. Figure 2 The XRD spectrum analysis showed that the shifted characteristic peak of rubidium chloride was detected in the roasted sample, indicating that the roasting process was a chlorination reaction under the interaction of lithium ore waste rock tailings and chlorinating agent, the structure of rubidium ore was destroyed, and rubidium ions combined with chloride ions to form corresponding rubidium chloride. Figure 2 The characteristic peak of rubidium chloride in the leached sample disappeared, indicating that during the leaching process, chloride salts represented by rubidium chloride were dissolved into the leachate.

[0047] Comparative Example 1

[0048] The rest is the same as in Example 1, except that anhydrous calcium chloride is used as the chlorinating agent, and the amount of the chlorinating agent is the same as in Example 1. The specific steps are as follows:

[0049] S1. Take 10g of lithium ore waste rock tailings, dry, crush and sieve to obtain lithium ore waste slag powder with a particle size range of 0-100μm exceeding 98%. The lithium ore tailings used in this embodiment have an Fe content of 3.6wt%, an Al content of 20.7wt%, a Si content of 62.4wt% and a Ca content of 4.3wt%.

[0050] S2. After fully mixing anhydrous calcium chloride chlorinating agent, lithium ore waste powder and neutralizing agent sodium carbonate, they are mixed into balls in a mass ratio of 5:10:2. The drying environment temperature is set to 105°C and the drying time is 24 hours to obtain dry green balls.

[0051] S3, heating the dried green balls to 900° C. and calcining for 2 hours to obtain calcined materials.

[0052] S4, taking out the calcined material and grinding it into powder using a ceramic mortar, and subjecting it to a water leaching process at a leaching temperature of 25° C. and a leaching time of 1 h, and obtaining a rubidium-enriched solution and a leaching residue through solid-liquid separation of the leaching liquid.

[0053] The rubidium ion concentration in the rubidium enriched solution was measured by atomic absorption spectrophotometer. The specific amount of raw material ratio is shown in Table 1, and the basic data of the leaching solution is shown in Table 2.

[0054] The results show that under this condition, the rubidium concentration in the rubidium-enriched solution is 222.00 mg / L and the rubidium extraction rate is 62.54%.

[0055] Comparative Example 2

[0056] The rest is the same as Example 2, except that anhydrous calcium chloride is used as the chlorinating agent, and the amount of the chlorinating agent is the same as that of Example 2. The specific steps are as follows:

[0057] S1. Take 10g of lithium ore waste rock tailings, dry, crush and sieve to obtain lithium ore waste slag powder with a particle size range of 0-100μm exceeding 98%. The lithium ore tailings used in this embodiment have an Fe content of 3.6wt%, an Al content of 20.7wt%, a Si content of 62.4wt% and a Ca content of 4.3wt%.

[0058] S2. After fully mixing anhydrous calcium chloride chlorinating agent, lithium ore waste powder and neutralizing agent sodium carbonate, they are mixed into balls in a mass ratio of 6:10:2. The drying environment temperature is set to 105°C and the drying time is 24 hours to obtain dry green balls.

[0059] S3, heating the dried green balls to 900° C. and calcining for 2 hours to obtain calcined materials.

[0060] S4, taking out the calcined material and grinding it into powder using a ceramic mortar, and subjecting it to a water leaching process at a leaching temperature of 25° C. and a leaching time of 1 h, and obtaining a rubidium-enriched solution and a leaching residue through solid-liquid separation of the leaching liquid.

[0061] The rubidium ion concentration in the rubidium enriched solution was measured by atomic absorption spectrophotometer. The specific amount of raw material ratio is shown in Table 1, and the basic data of the leaching solution is shown in Table 2.

[0062] The results showed that under these conditions, the rubidium concentration in the rubidium-enriched solution was 244.51 mg / L and the rubidium extraction rate was 72.16%.

[0063] The raw material proportions of the above-mentioned embodiments and comparative examples are shown in Table 1, and the basic data of the leaching solution are shown in Table 2.

[0064] Table 1 Raw material ratios of each embodiment and comparative example

[0065]

[0066] Note: In Table 1, the chlorinating agent Cl- content in Example 1 and Example 2 is calculated by chlorinating agent concentration × chlorinating agent volume.

[0067] Table 2 Basic data of the leachate of each embodiment and comparative example

[0068]

[0069] It can be seen from the above comparison results that the present invention uses fly ash leachate as the chlorinating agent, which significantly improves the extraction effect of rubidium compared to directly using chloride as the chlorinating agent.

Claims

1. A method for extracting rubidium by using fly ash leaching solution in conjunction with lithium ore waste residue, characterized in that: The following steps are involved: S1. Select lithium ore waste and crush it into a particle size range of 0 to 100 μm to obtain lithium ore waste powder; S2. Selecting fly ash for water washing and dechlorination, and then controlling the chlorine concentration of the fly ash leachate to 200-800 g / L by evaporation of water to obtain a chlorinating agent; S3. The chlorinating agent obtained in S2, the lithium ore waste powder obtained in S1 and the neutralizing agent are fully mixed into balls, and then dried to obtain dry green balls; S4. The dried green pellets obtained in S3 are heated to 600-1000°C and calcined for 1-3 hours to obtain a calcined material; S5. The roasted material obtained in S4 is taken out for water leaching, and the leaching liquid is separated into rubidium-enriched liquid and leaching residue by solid-liquid separation.

2. The method for extracting rubidium by using fly ash leaching solution in conjunction with lithium ore waste residue according to claim 1, characterized in that: In step S1, the particle size range of the lithium ore waste slag powder is 0-100 μm and reaches more than 98%.

3. The method for extracting rubidium by using fly ash leaching solution in conjunction with lithium ore waste residue according to claim 1, characterized in that: In step S2, the chlorine content in the fly ash is not less than 200 mg / g.

4. The method for extracting rubidium by using fly ash leaching solution in conjunction with lithium ore waste residue according to claim 1, characterized in that: In step S2, the chlorine concentration of the chlorinating agent is 600-700 g / L.

5. The method for extracting rubidium by using fly ash leaching solution in conjunction with lithium ore waste residue according to claim 1, characterized in that: In step S2, in the water washing dechlorination, the solid-liquid mass ratio of fly ash to water is 1:3-5, the stirring speed is 300-600 r / min, the water washing temperature is 30-50° C., and the dechlorination time is 30-60 min.

6. The method for extracting rubidium by using fly ash leaching solution in conjunction with lithium ore waste residue according to claim 1, characterized in that: In step S3, the mass ratio of the chlorinating agent, the lithium ore waste powder and the neutralizing agent is 3-7:10:

2.

7. The method for extracting rubidium by using fly ash leaching solution in conjunction with lithium ore waste residue according to claim 1, characterized in that: In step S3, the neutralizing agent is sodium carbonate; the drying temperature is 70 to 105° C., and the drying time is 12 to 24 hours.

8. The method for extracting rubidium by using fly ash leaching solution in conjunction with lithium ore waste residue according to claim 1, characterized in that: In step S3, the moisture content of the pellets before drying is controlled at 5-20%, and the particle size of the pellets is controlled at 17-34 mm.

9. The method for extracting rubidium by using fly ash leaching solution in conjunction with lithium ore waste residue according to claim 1, characterized in that: In step S5, the water immersion temperature of the roasted material is 20-25° C., and the leaching time is 0.5-2 h.

10. The method for extracting rubidium by using fly ash leaching solution in conjunction with lithium ore waste residue according to claim 1, characterized in that: In step S5, the particle size of the roasting material is controlled to be 20-30 mm, and the mass ratio of the roasting material to water is 1:3-6.

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