Method for efficiently extracting lithium from high-potassium and high-phosphorus complex spodumene ore

Abstract

The invention discloses a method for efficiently extracting lithium from high-potassium and high-phosphorus complex spodumene ore, which comprises the following steps: firstly, uniformly mixing high-potassium and high-phosphorus complex spodumene concentrate with an auxiliary agent 1 and an auxiliary agent 2, and roasting to obtain a roasted material; secondly, uniformly mixing the roasted material with a proper amount of sulfuric acid, and performing low-temperature calcination to obtain an acidified material; and finally, placing the acidified material in water for water leaching, and then carrying out solid-liquid separation to obtain a lithium leaching solution and lithium leaching tailings, compared with a traditional sulfuric acid method, the method has the advantages that the melting and sintering phenomena generated during transformation roasting of the high-potassium and high-phosphorus complex spodumene ore can be obviously relieved, and the extraction efficiency of lithium is obviously improved; the technological process provided by the invention is very simple, the added auxiliaries are relatively low in price, and the method plays an extremely important role in efficient development and utilization of complex spodumene ores with relatively high contents of potassium, phosphorus and the like, and has good industrial application value and popularization prospect.

Description

Technical Field

[0001] The invention relates to the technical field of lithium extraction from lithium ore, and in particular to a method for efficiently extracting lithium from a complex spodumene ore containing high potassium and high phosphorus. Background Art

[0002] Complex spodumene ores usually contain mica, pyroxenite, petalite, etc., and have high contents of impurity elements such as potassium and phosphorus, which makes the extraction of lithium face many difficulties and challenges. When using the traditional sulfuric acid method to treat such ores, there are often problems such as roasting, melting and agglomeration on the production line and low lithium extraction rate. Therefore, it is urgent to develop a new method for efficient lithium extraction from complex spodumene ores with high potassium and phosphorus. Summary of the invention

[0003] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a method for efficiently extracting lithium from a complex spodumene ore with high potassium and high phosphorus, comprising the following steps: first, uniformly mixing the complex spodumene concentrate with high potassium and high phosphorus with auxiliary agents 1 and 2 and then roasting to obtain a roasting material; secondly, uniformly mixing the roasting material with an appropriate amount of sulfuric acid and then calcining at a low temperature to obtain an acidified material; finally, immersing the acidified material in water, and then performing solid-liquid separation to obtain a lithium leaching solution and lithium leaching tailings; compared with the traditional sulfuric acid method, this method can significantly alleviate the melting and sintering phenomenon generated by the complex spodumene ore with high potassium and high phosphorus during transition roasting, and significantly improves the extraction efficiency of lithium; the process flow proposed by the present invention is very simple, the price of the added auxiliary agents is relatively low, and it plays an extremely critical and important role in the efficient development and utilization of complex spodumene ore with high potassium, phosphorus and other contents, and has good industrial application value and promotion prospects.

[0004] In order to achieve the above technical effects, the following technical solutions are adopted: A method for efficiently extracting lithium from a complex spodumene ore with high potassium and high phosphorus content comprises the following steps: Step S1: uniformly mixing the high-potassium and high-phosphorus complex spodumene concentrate with the additives 1 and 2, and then performing transformation roasting to obtain a roasting material; Step S2: uniformly mixing the roasted material in step S1 with sulfuric acid, and then calcining at low temperature to obtain an acidified material; Step S3: placing the acidified material in step S2 in water for water leaching, and then performing solid-liquid separation to obtain lithium leaching solution and lithium leaching tailings, wherein the lithium extraction rate in the leaching solution is greater than 80%.

[0005] Furthermore, the high-potassium and high-phosphorus complex spodumene concentrate has a lithium content of 1.40-3.30wt%, a potassium content of 0.80-5.20wt%, and a phosphorus content of 0.60-5.30wt%.

[0006] Furthermore, the auxiliary agent 1 is one or more of calcium oxide, calcium hydroxide, and calcium carbonate; the auxiliary agent 2 is one or more of lepidolite, ferrolithium mica, calcium fluoride, sodium fluoride, and ammonium bifluoride.

[0007] Furthermore, the auxiliary agent 1 is a mixture of two components a and b, wherein component a is one or more of calcium oxide, calcium hydroxide, and calcium carbonate; component b is one or more of magnesium oxide, aluminum oxide, and iron oxide; the mass ratio of components a and b in the auxiliary agent 1 is 1:2~5:1; and the auxiliary agent 2 is one or more of lithium mica, iron lithium mica, calcium fluoride, sodium fluoride, and ammonium bifluoride.

[0008] Furthermore, the mixing mass ratio of the high-potassium and high-phosphorus complex spodumene concentrate and the additive 1 is 1:0.01~1:0.1; the mixing mass ratio of the high-potassium and high-phosphorus complex spodumene concentrate and the additive 2 is 1:0.03~1:0.50.

[0009] Furthermore, the transition calcination temperature in step S1 is 950-1100° C.; the transition calcination time in step S1 is 30-90 min.

[0010] The roasting conditions have a significant impact on the final lithium extraction effect. When the roasting temperature is too low or the reaction time is too short, the complex spodumene ore with high potassium and high phosphorus cannot fully react with the added additives, the crystal transformation of spodumene and the destruction of chemical bonds are incomplete and insufficient, and the lithium extraction effect is reduced; when the roasting temperature is too high or the reaction time is too long, it will cause excessive energy consumption and increase production costs. Some metal impurities in the ore may also form complex compounds with lithium or the ore may melt and sinter as a whole, which is not conducive to the further extraction of lithium. Therefore, it is advisable to control the temperature and reaction time of the transition roasting within an appropriate range.

[0011] Furthermore, in step S2, the amount of sulfuric acid mixed with the calcined material is 1.5 to 4.5 times the theoretical acid consumption when all the lithium elements in the complex spodumene ore with high potassium and high phosphorus are converted into lithium sulfate, and the sulfuric acid used is concentrated sulfuric acid.

[0012] If the amount of sulfuric acid used is too low, the lithium cannot be completely replaced, resulting in a low lithium leaching rate; if the amount of sulfuric acid used is too high, the content of impurity elements in the lithium leaching solution will increase, equipment corrosion will increase, and production costs will increase.

[0013] Furthermore, the temperature of the low-temperature calcination in step S2 is 150-300°C.

[0014] Furthermore, the low-temperature calcination time in step S2 is 10 to 60 minutes.

[0015] Controlling the calcination temperature and duration within an appropriate range helps to improve the replacement efficiency of hydrogen ions in sulfuric acid with lithium ions in the ore. Too low a calcination temperature or too short a calcination time will result in insufficient lithium replacement rate, while too high a calcination temperature or too long a calcination time will increase calcination energy consumption and increase production costs.

[0016] Furthermore, the water immersion reaction conditions in step S3 are: liquid-solid ratio of 2-8 mL:1 g, temperature of 20-80° C., and time of 30-90 min.

[0017] The appropriate liquid-to-solid ratio can ensure that the lithium element in the ore is fully dissolved in the leachate. If the liquid-to-solid ratio is too low, the amount of solution is insufficient to completely dissolve the lithium in the ore, which will lead to a decrease in the lithium extraction rate; if the liquid-to-solid ratio is too high, not only will the concentration of lithium in the leachate be too low, but it will also increase the volume of the leachate, making it difficult for the subsequent lithium separation and purification steps.

[0018] The appropriate leaching temperature can speed up the reaction rate of lithium dissolving from the ore. If the leaching temperature is too low, the lithium dissolution rate is slow; if the leaching temperature is too high, impurities such as potassium and phosphorus in the ore may be excessively dissolved and energy consumption may be increased.

[0019] Appropriate leaching time is one of the key factors to ensure that lithium in spodumene is fully dissolved. If the leaching time is too short, lithium leaching is insufficient and incomplete; if the leaching time is too long, production efficiency will be reduced.

[0020] The beneficial effects of the present invention are: (1) The present invention can effectively alleviate the melting and sintering of complex spodumene ore with high potassium and high phosphorus during transition roasting, and improve production conditions. When the complex spodumene ore with high potassium and high phosphorus is treated by the traditional sulfuric acid method, the ore material will have serious melting and agglomeration phenomenon on the production line during transition roasting. After adding the above-mentioned additives, the technical solution can significantly alleviate the melting and sintering phenomenon of complex spodumene ore with high potassium and high phosphorus during high-temperature roasting, which is of great significance for improving production conditions and increasing production efficiency.

[0021] (2) The present invention can significantly improve the leaching rate of lithium from high-potassium and high-phosphorus complex spodumene ores. When the traditional sulfuric acid method is used to treat high-potassium and high-phosphorus complex spodumene ores alone, the lithium extraction effect is often poor, and the leaching rate is concentrated in the range of 50-60%. After the above-mentioned additives are added to the technical solution, the ore is obviously activated and extracted, and the lithium leaching rate is generally greater than 80%. Under the special combination of additives, the lithium leaching rate can be further improved to more than 95%. The lithium extraction rate obtained by treating complex spodumene ores with this technical solution is greatly improved compared with the traditional sulfuric acid method, which solves the problem of low lithium extraction rate of high-potassium and high-phosphorus complex spodumene ores, improves the comprehensive utilization rate of lithium resources, reduces resource waste, and expands economic benefits.

[0022] (3) The present invention reduces the temperature of transition roasting to a certain extent. When using the traditional sulfuric acid method to treat complex spodumene ore with high potassium and high phosphorus alone, it is often necessary to perform transition roasting at above 1050°C to obtain a high lithium leaching rate. After adding the above-mentioned additives, the technical solution can obtain a leaching rate better than that of the sulfuric acid method alone at about 950~1000°C.

[0023] (4) The process flow used in the present invention is very simple, the added additives are harmless, cheap and easy to obtain, and will not lead to a large increase in leaching residues. The method is mature, low-cost, and the system has strong adaptability. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. The drawings in the following description are merely embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0025] Figure 1 It is a process schematic diagram of a method for efficiently extracting lithium from a complex spodumene ore with high potassium and high phosphorus provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the 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.

[0027] It should be noted that the following detailed descriptions are exemplary and are intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0028] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, it indicates the presence of features, steps, operations and / or combinations thereof.

[0029] Embodiment 1: according to Figure 1 As shown, the lithium extraction operation of the complex spodumene mine with high potassium and high phosphorus is carried out: Take Li content of 2.33wt.%, K content of 1.36wt.%, P content of 4.22wt.% high potassium and high phosphorus complex spodumene concentrate 100g and auxiliary agent 1 calcium oxide 1g and auxiliary agent 2 ammonium bifluoride 3g uniformly mixed, then placed in a muffle furnace for transition roasting, the roasting temperature is set to 950°C, and the roasting time is 90min. After the roasting material is cooled to 100°C, it is ball-milled to less than 100 mesh, and then concentrated sulfuric acid is added and uniformly mixed according to 2.0 times of the theoretical acid consumption, and the mixed acid material is placed in a muffle furnace for low-temperature calcination, and the calcination temperature is set to 150°C, and the calcination time is 60min to obtain an acidified material. Subsequently, the acidified material is placed in water for water immersion according to a liquid-solid ratio of 2mL:1g, and the leaching temperature is set to 20°C for 90min. After leaching, it is filtered to obtain lithium leachate and lithium tailings.

[0030] After testing and analysis, the leaching rate of Li in the leaching solution obtained in Example 1 was 83.21%, and the roasted sample was relatively fluffy after transition roasting, without obvious melting and sintering phenomenon. This shows that the technical solution can obtain an ideal lithium extraction rate from a complex spodumene concentrate with high potassium and high phosphorus at a lower energy consumption (950°C), and effectively alleviate the melting and sintering of a complex spodumene ore with high potassium and high phosphorus during transition roasting.

[0031] Embodiment 2: according to Figure 1 As shown, the lithium extraction operation of the complex spodumene mine with high potassium and high phosphorus is carried out: Take Li content of 2.33wt.%, K content of 1.36wt.%, P content of 4.22wt.%, high potassium and high phosphorus complex spodumene concentrate 100g and auxiliary agent 1 calcium oxide 10g and auxiliary agent 2 lithium mica 50g uniformly mixed, then placed in a muffle furnace for transition roasting, roasting temperature is set to 1100 ° C, roasting time is 30min. After the roasting material is cooled to 100 ° C, it is ball-milled to less than 100 mesh, then concentrated sulfuric acid is added and uniformly mixed according to 4.5 times of theoretical acid consumption, and the mixed acid material is placed in a muffle furnace for low-temperature calcination, and the calcination temperature is set to 300 ° C, and the calcination time is 10min to obtain an acidified material. Subsequently, the acidified material is placed in water for water immersion according to a liquid-solid ratio of 8mL: 1g, and the leaching temperature is set to 80 ° C, and the time is 30min. After leaching, it is filtered to obtain lithium leachate and lithium tailings.

[0032] After testing and analysis, the leaching rate of Li in the leaching solution obtained in Example 2 is 85.05%, and the roasted sample is relatively fluffy after transition roasting, without obvious melting and sintering phenomenon. It shows that the technical scheme can obtain an ideal lithium extraction rate from a complex spodumene concentrate with high potassium and high phosphorus, and effectively alleviate the melting and sintering of a complex spodumene ore with high potassium and high phosphorus during transition roasting.

[0033] Embodiment 3: according to Figure 1 As shown, the lithium extraction operation of the complex spodumene mine with high potassium and high phosphorus is carried out: Take Li content of 2.33wt.%, K content of 1.36wt.%, P content of 4.22wt.%, high potassium and high phosphorus complex spodumene concentrate 100g and auxiliary agent 1 calcium oxide 3g and auxiliary agent 2 calcium fluoride 10g uniformly mixed, then placed in a muffle furnace for transition roasting, the roasting temperature is set to 1000 ° C, and the roasting time is 60min. After the roasting material is cooled to 100 ° C, it is ball-milled to less than 100 mesh, and then concentrated sulfuric acid is added according to 3.0 times of the theoretical acid consumption and uniformly mixed, and the mixed acid material is placed in a muffle furnace for low-temperature calcination, and the calcination temperature is set to 250 ° C, and the calcination time is 40min to obtain an acidified material. Subsequently, the acidified material is placed in water for water immersion according to a liquid-solid ratio of 4mL: 1g, and the leaching temperature is set to 45 ° C, and the time is 30min. After leaching, it is filtered to obtain lithium leachate and lithium tailings.

[0034] After testing and analysis, the leaching rate of Li in the leaching solution obtained in Example 3 was 84.65%, and the roasted sample was relatively fluffy after transition roasting, without obvious melting and sintering phenomenon. This shows that the technical solution can obtain an ideal lithium extraction rate from a complex spodumene concentrate with high potassium and high phosphorus, and effectively alleviate the melting and sintering of a complex spodumene ore with high potassium and high phosphorus during transition roasting.

[0035] Embodiment 4: according to Figure 1 As shown, the lithium extraction operation of the complex spodumene mine with high potassium and high phosphorus is carried out: Take Li content of 2.33wt.%, K content of 1.36wt.%, P content of 4.22wt.%, high potassium and high phosphorus complex spodumene concentrate 100g and auxiliary agent 1 calcium hydroxide 3g and auxiliary agent 2 iron lithium mica 25g uniformly mixed, then placed in a muffle furnace for transition roasting, roasting temperature is set to 1000 ° C, roasting time is 60min. After the roasting material is cooled to 100 ° C, it is ball-milled to less than 100 mesh, then concentrated sulfuric acid is added according to 3.0 times of theoretical acid consumption and uniformly mixed, and the mixed acid material is placed in a muffle furnace for low-temperature calcination, and the calcination temperature is set to 250 ° C, and the calcination time is 40min to obtain an acidified material. Subsequently, the acidified material is placed in water for water immersion according to a liquid-solid ratio of 4mL: 1g, and the leaching temperature is set to 45 ° C, and the time is 30min. After leaching, it is filtered to obtain lithium leachate and lithium tailings.

[0036] After testing and analysis, the leaching rate of Li in the leaching solution obtained in Example 4 was 83.47%, and the roasted sample was relatively fluffy after transition roasting, without obvious melting and sintering phenomenon. This shows that the technical solution can obtain an ideal lithium extraction rate from a complex spodumene concentrate with high potassium and high phosphorus, and effectively alleviate the melting and sintering of a complex spodumene ore with high potassium and high phosphorus during transition roasting.

[0037] Embodiment 5: according to Figure 1 As shown, the lithium extraction operation of the complex spodumene mine with high potassium and high phosphorus is carried out: Take Li content of 2.33wt.%, K content of 1.36wt.%, P content of 4.22wt.%, high potassium and high phosphorus complex spodumene concentrate 100g and auxiliary agent 1 calcium carbonate 5g and auxiliary agent 2 sodium fluoride 4g uniformly mixed, then placed in a muffle furnace for transition roasting, roasting temperature is set to 1000 ° C, roasting time is 60min. After the roasting material is cooled to 100 ° C, it is ball-milled to less than 100 mesh, then concentrated sulfuric acid is added according to 3.0 times of theoretical acid consumption and uniformly mixed, and the mixed acid material is placed in a muffle furnace for low-temperature calcination, and the calcination temperature is set to 250 ° C, and the calcination time is 40min to obtain an acidified material. Subsequently, the acidified material is placed in water for water immersion according to a liquid-solid ratio of 4mL: 1g, and the leaching temperature is set to 45 ° C, and the time is 30min. After leaching, it is filtered to obtain lithium leachate and lithium tailings.

[0038] After testing and analysis, the leaching rate of Li in the leaching solution obtained in Example 5 was 83.33%, and the roasted sample was observed to be relatively fluffy after transition roasting, without obvious melting and sintering phenomenon. This shows that the technical solution can obtain an ideal lithium extraction rate from a complex spodumene concentrate with high potassium and high phosphorus, and effectively alleviate the melting and sintering of a complex spodumene ore with high potassium and high phosphorus during transition roasting.

[0039] Embodiment 6: according to Figure 1 As shown, the lithium extraction operation of the complex spodumene mine with high potassium and high phosphorus is carried out: Take Li content of 2.20wt.%, K content of 2.12wt.%, P content of 1.42wt.% high potassium and high phosphorus complex spodumene concentrate 100g and auxiliary agent 1 calcium oxide 3g and auxiliary agent 2 calcium fluoride 10g uniformly mixed, then placed in a muffle furnace for transition roasting, roasting temperature is set to 1050 ° C, roasting time is 60min. After the roasting material is cooled to 100 ° C, it is ball-milled to less than 100 mesh, then concentrated sulfuric acid is added according to 2.0 times of theoretical acid consumption and uniformly mixed, and the mixed acid material is placed in a muffle furnace for low-temperature calcination, and the calcination temperature is set to 250 ° C, and the calcination time is 40min to obtain an acidified material. Subsequently, the acidified material is placed in water for water immersion according to a liquid-solid ratio of 4mL: 1g, and the leaching temperature is set to 45 ° C, and the time is 30min. After leaching, it is filtered to obtain lithium leachate and lithium tailings.

[0040] After testing and analysis, the leaching rate of Li in the leaching solution obtained in Example 6 was 85.73%, and the roasted sample was relatively fluffy after transition roasting, without obvious melting and sintering phenomenon. This shows that the technical solution can obtain an ideal lithium extraction rate from a complex spodumene concentrate with high potassium and high phosphorus, and effectively alleviate the melting and sintering of a complex spodumene ore with high potassium and high phosphorus during transition roasting.

[0041] Comparative Example 1: The method of Example 1 was used to extract lithium, except that only auxiliary agent 2 (4 g) was added, and the transition roasting temperature was 800° C.; the rest remained the same.

[0042] After testing and analysis, the leaching rate of Li in the leaching solution obtained in Comparative Example 1 was 4.38%.

[0043] Comparative Example 2: Lithium was extracted by the method of Example 1, except that: auxiliary agent 1 (1 g) and auxiliary agent 2 (3 g) were added, but the transition roasting temperature was 800° C.; the rest remained the same.

[0044] After testing and analysis, the leaching rate of Li in the leaching solution obtained in Comparative Example 1 was 4.68%.

[0045] Comparative Example 3: Lithium was extracted by the method of Example 1, except that only auxiliary agent 2 (4 g) was added, and the transition calcination temperature was 900° C.; the rest remained the same.

[0046] After testing and analysis, the leaching rate of Li in the leaching solution obtained in Comparative Example 1 was 20.77%.

[0047] Comparative Example 4: Lithium was extracted by the method of Example 1, except that: auxiliary agent 1 (1 g) and auxiliary agent 2 (3 g) were added, but the transition roasting temperature was 900° C.; the rest remained the same.

[0048] After testing and analysis, the leaching rate of Li in the leaching solution obtained in Comparative Example 1 was 60.39%.

[0049] Comparative Example 5: The method of Example 1 was used to extract lithium, except that: additives 1 and 2 were not added, the transition roasting temperature was 1000° C., and the rest remained the same.

[0050] After testing and analysis, the leaching rate of Li in the leaching solution obtained in Comparative Example 1 was 50.41%.

[0051] Comparative Example 6: Lithium was extracted by the method of Example 1, except that only auxiliary agent 2 (4 g) was added, and the transition calcination temperature was 1000° C.; the rest remained the same.

[0052] After testing and analysis, the leaching rate of Li in the leaching solution obtained in Comparative Example 1 was 65.23%.

[0053] Comparative Example 7: Lithium was extracted using the method of Example 1, except that only additive 1 (4 g) was added, and the transition calcination temperature was 1000° C.; the rest remained the same.

[0054] After testing and analysis, the leaching rate of Li in the leaching solution obtained in Comparative Example 1 was 55.71%.

[0055] Comparative Example 8: Lithium was extracted using the method of Example 1, except that the calcium oxide in the auxiliary agent 1 was replaced with copper oxide (1 g), and the transition roasting temperature was 1000° C.; the rest remained the same.

[0056] After testing and analysis, the leaching rate of Li in the leaching solution obtained in Comparative Example 1 was 68.49%.

[0057] Embodiment 7: The method of Example 3 was used to extract lithium, except that the auxiliary agent 1 was changed to 1g of calcium oxide and 2g of magnesium oxide, while the other ingredients remained unchanged.

[0058] After testing and analysis, the leaching rate of Li in the leaching solution obtained under the conditions of this embodiment is 96.31%. After the transition roasting, the roasted sample is observed to be more fluffy, and the melt sintering phenomenon is less obvious. Compared with Example 3, the lithium leaching effect of Example 7 is further improved, indicating that the combined addition of additive 1 is better than the single addition effect.

[0059] Embodiment 8: The method of Example 3 was used to extract lithium, except that the auxiliary agent 1 was changed to 1.5 g of calcium oxide and 1.5 g of aluminum oxide, while the other ingredients remained unchanged.

[0060] After testing and analysis, the leaching rate of Li in the leaching solution obtained under the conditions of this embodiment is 95.87%. After the transition roasting, the roasted sample is observed to be more fluffy, and the melt sintering phenomenon is less obvious. Compared with Example 3, the lithium leaching effect of Example 8 is further improved, indicating that the combined addition of additive 1 is better than the single addition effect.

[0061] Embodiment 9: The method of Example 3 was used to extract lithium, except that the auxiliary agent 1 was changed to 2 g of calcium oxide and 1 g of iron oxide, while the other ingredients remained unchanged.

[0062] After testing and analysis, the leaching rate of Li in the leaching solution obtained under the conditions of this embodiment is 95.93%. After the transition roasting, the roasted sample is observed to be more fluffy, and the melt sintering phenomenon is less obvious. Compared with Example 3, the lithium leaching effect of Example 9 is further improved, indicating that the combined addition of additive 1 is better than the single addition effect.

[0063] Embodiment 10: The method of Example 3 was used to extract lithium, except that the auxiliary agent 1 was changed to 2.5 g of calcium hydroxide and 0.5 g of magnesium oxide, while the other ingredients remained unchanged.

[0064] After testing and analysis, the leaching rate of Li in the leaching solution obtained under the conditions of this embodiment is 95.47%. After the transition roasting, the roasted sample is observed to be more fluffy, and the melt sintering phenomenon is less obvious. Compared with Example 3, the lithium leaching effect of Example 10 is further improved, indicating that the combined addition of additive 1 is better than the single addition.

[0065] Embodiment 11: The method of Example 3 was used to extract lithium, except that the auxiliary agent 1 was changed to 2 g of calcium hydroxide and 1 g of aluminum oxide, while the other ingredients remained unchanged.

[0066] After testing and analysis, the leaching rate of Li in the leaching solution obtained under the conditions of this embodiment is 96.14%. After the transition roasting, the roasted sample is observed to be more fluffy, and the melt sintering phenomenon is less obvious. Compared with Example 3, the lithium leaching effect of Example 11 is further improved, indicating that the combined addition of additive 1 is better than the single addition effect.

[0067] Embodiment 12: The method of Example 3 was used to extract lithium, except that the auxiliary agent 1 was changed to 1.5 g of calcium hydroxide and 1.5 g of iron oxide, while the other ingredients remained unchanged.

[0068] After testing and analysis, the leaching rate of Li in the leaching solution obtained under the conditions of this embodiment is 96.02%. After the transition roasting, the roasted sample is observed to be more fluffy, and the melt sintering phenomenon is less obvious. Compared with Example 3, the lithium leaching effect of Example 12 is further improved, indicating that the combined addition of additive 1 is better than the single addition effect.

[0069] Comparative Example 9: The method of Example 7 was used to extract lithium, except that the additive 2 was not added, the additive 1 was changed to 4.33 g of calcium oxide and 8.67 g of magnesium oxide, the transition calcination temperature was 1000° C., and the others remained the same.

[0070] After testing and analysis, the leaching rate of Li in the leaching solution obtained under the conditions of this embodiment is 56.84%.

[0071] Comparative Example 10: The method of Example 7 was used to extract lithium, except that the auxiliary agent 1 was changed to 3g of calcium oxide and the auxiliary agent 2 was 10g. This was the technical solution of Example 3. The transition roasting temperature was 1000°C; the others remained the same.

[0072] After testing and analysis, the leaching rate of Li in the leaching solution obtained under the conditions of this embodiment is 84.65%.

[0073] Comparative Example 11: The method of Example 7 was used to extract lithium, except that the auxiliary agent 1 was changed to 3 g of magnesium oxide, the auxiliary agent 2 was 10 g, the transition roasting temperature was 1000° C., and the other parameters remained the same.

[0074] After testing and analysis, the leaching rate of Li in the leaching solution obtained under the conditions of this embodiment is 82.69%.

[0075] Comparative Example 12: Lithium was extracted by the method of Example 7, except that only calcium oxide (13 g) in auxiliary agent 1 was added, auxiliary agent 2 was not added, and the transition roasting temperature was 1000° C.; the rest remained the same.

[0076] After testing and analysis, the leaching rate of Li in the leaching solution obtained in Comparative Example 1 was 58.51%.

[0077] Comparative Example 13: Lithium was extracted by the method of Example 7, except that only magnesium oxide (13 g) in auxiliary agent 1 was added, auxiliary agent 2 was not added, and the transition roasting temperature was 1000° C.; the other parameters remained the same.

[0078] After testing and analysis, the leaching rate of Li in the leaching solution obtained in Comparative Example 1 was 56.32%.

[0079] Comparative Example 14: Lithium was extracted using the method of Example 7, except that only additive 2 (13 g) was added, the transition calcination temperature was 1000° C., and the rest remained the same.

[0080] After testing and analysis, the leaching rate of Li in the leaching solution obtained in Comparative Example 1 was 68.79%.

[0081] Comparative Example 15: The method of Example 7 was used to extract lithium, except that the calcium oxide in the auxiliary agent 1 was replaced by copper oxide, and the transition roasting temperature was 1000° C.; the rest remained the same.

[0082] After testing and analysis, the leaching rate of Li in the leaching solution obtained in Comparative Example 1 was 80.57%.

[0083] Comparative Example 16: Lithium was extracted using the method of Example 7, except that the magnesium oxide in the auxiliary agent 1 was replaced by copper oxide, and the transition roasting temperature was 1000° C.; the rest remained the same.

[0084] After testing and analysis, the leaching rate of Li in the leaching solution obtained in Comparative Example 1 was 81.37%.

[0085] Comparative Example 17: The method of Example 7 was used to extract lithium, except that the amount of sulfuric acid used was 1.5 times the theoretical acid consumption.

[0086] After testing and analysis, the leaching rate of Li in the leaching solution obtained under the conditions of this embodiment is 75.50%. After the transition roasting, the roasted sample is relatively fluffy and there is no obvious melting sintering phenomenon. Compared with Example 7, the lithium leaching effect is poor, indicating that the amount of acid is insufficient to completely complete the replacement of lithium. The auxiliary agent 1 added in this technical solution will consume sulfuric acid, so in actual implementation, the amount of sulfuric acid should be properly increased or decreased according to the amount of auxiliary agent 1 added.

[0087] It can be seen from the above experiments that the present application greatly improves the lithium extraction rate of complex spodumene concentrate with high potassium and high phosphorus through the synergistic effect of additives 1 and additives 2. When additive 1 is one or more of calcium oxide, calcium hydroxide, and calcium carbonate, the lithium extraction rate of complex spodumene concentrate with high potassium and high phosphorus can reach about 85%. When additive 1 is a mixture of two components a and b, component a is one or more of calcium oxide, calcium hydroxide, and calcium carbonate; component b is one or more of magnesium oxide, aluminum oxide, and iron oxide, the lithium extraction rate of complex spodumene concentrate with high potassium and high phosphorus is more than 95%. The components in additive 1 and additive 2 are synergistically enhanced with each other, so that the lithium extraction rate of complex spodumene concentrate with high potassium and high phosphorus is greatly improved.

[0088] In summary, the present invention discloses a method for efficiently extracting lithium from a complex spodumene ore with high potassium and high phosphorus, comprising the following steps: first, uniformly mixing the complex spodumene concentrate with high potassium and high phosphorus with auxiliary agents 1 and 2, and then performing transition roasting to obtain a roasting material; secondly, uniformly mixing the roasting material with an appropriate amount of sulfuric acid, and then performing low-temperature calcination to obtain an acidified material; finally, placing the acidified material in water for water immersion, and then performing solid-liquid separation to obtain a lithium leaching solution and lithium leaching tailings; compared with the traditional sulfuric acid method, this method can significantly alleviate the melting and sintering phenomenon generated by the complex spodumene ore with high potassium and high phosphorus during transition roasting, and significantly improves the extraction efficiency of lithium; the process flow proposed by the technical scheme is very simple, and the price of the added auxiliary agents is relatively low, which plays an extremely critical and important role in the efficient development and utilization of complex spodumene ore with high contents of potassium, phosphorus, etc., and has good industrial application value and promotion prospects.

[0089] At this point, those skilled in the art recognize that, although the embodiments of the present invention have been shown and described in detail herein, many other variations or modifications that conform to the principles of the present invention can still be directly determined or derived based on the contents disclosed in the present invention without departing from the spirit and scope of the present invention. Therefore, the scope of the present invention should be understood and recognized as covering all such other variations or modifications.

Claims

1. A method for efficiently extracting lithium from a complex spodumene ore with high potassium and high phosphorus content, characterized in that: The lithium extraction method comprises the following steps: Step S1: uniformly mixing the high-potassium and high-phosphorus complex spodumene concentrate with the additives 1 and 2, and then performing transformation roasting to obtain a roasting material; Step S2: uniformly mixing the roasted material in step S1 with sulfuric acid, and then calcining at low temperature to obtain an acidified material; Step S3: placing the acidified material in step S2 in water for water leaching, and then performing solid-liquid separation to obtain a lithium leaching solution and lithium leaching tailings, wherein the lithium extraction rate in the leaching solution is greater than 80%.

2. A method for efficiently extracting lithium from a complex spodumene ore with high potassium and high phosphorus as described in claim 1, characterized in that: The high-potassium and high-phosphorus complex spodumene concentrate has a lithium content of 1.40-3.30wt%, a potassium content of 0.80-5.20wt%, and a phosphorus content of 0.60-5.30wt%.

3. A method for efficiently extracting lithium from a complex spodumene ore with high potassium and high phosphorus as described in claim 1, characterized in that: The auxiliary agent 1 is one or more of calcium oxide, calcium hydroxide, and calcium carbonate; the auxiliary agent 2 is one or more of lepidolite, ferrolithium mica, calcium fluoride, sodium fluoride, and ammonium bifluoride.

4. A method for efficiently extracting lithium from a complex spodumene ore with high potassium and high phosphorus as described in claim 1, characterized in that: The auxiliary agent 1 is a mixture of two components a and b, wherein the component a is one or more of calcium oxide, calcium hydroxide, and calcium carbonate; the component b is one or more of magnesium oxide, aluminum oxide, and iron oxide; the mass ratio of the components a and b in the auxiliary agent 1 is 1:2~5:1; the auxiliary agent 2 is one or more of lithium mica, lithium iron mica, calcium fluoride, sodium fluoride, and ammonium bifluoride.

5. A method for efficiently extracting lithium from a complex spodumene ore with high potassium and high phosphorus as described in claim 1, characterized in that: The mixing mass ratio of the high-potassium and high-phosphorus complex spodumene concentrate and the additive 1 is 1:0.01-1:0.1; the mixing mass ratio of the high-potassium and high-phosphorus complex spodumene concentrate and the additive 2 is 1:0.03-1:0.

50.

6. A method for efficiently extracting lithium from a complex spodumene ore with high potassium and high phosphorus as described in claim 1, characterized in that: The transition calcination temperature in step S1 is 950-1100° C.; the transition calcination time in step S1 is 30-90 min.

7. A method for efficiently extracting lithium from a complex spodumene ore with high potassium and high phosphorus as described in claim 1, characterized in that: In step S2, the amount of the calcined material mixed with sulfuric acid is 1.5 to 4.5 times the theoretical acid consumption when all the lithium elements in the complex spodumene ore with high potassium and high phosphorus are converted into lithium sulfate, and the sulfuric acid used is concentrated sulfuric acid.

8. A method for efficiently extracting lithium from a complex spodumene ore with high potassium and high phosphorus as claimed in claim 1, characterized in that: The temperature of low temperature calcination in step S2 is 150-300°C.

9. A method for efficiently extracting lithium from a complex spodumene ore with high potassium and high phosphorus as claimed in claim 1, characterized in that: The low-temperature calcination time in step S2 is 10 to 60 minutes.

10. A method for efficiently extracting lithium from a complex spodumene ore with high potassium and high phosphorus as claimed in claim 1, characterized in that: The water immersion reaction conditions in step S3 are: liquid-to-solid ratio of 2-8 mL:1 g, temperature of 20-80° C., and time of 30-90 min.

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