A method for extracting lithium from high-potassium and high-phosphorus complex spodumene ore

Abstract

The application discloses a method for 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 additive 1 and an additive 2, and then performing roasting to obtain roasted materials; secondly, uniformly mixing the roasted materials with appropriate sulfuric acid, and then performing low-temperature calcination to obtain acidized materials; finally, placing the acidized materials in water for water immersion, and then performing solid-liquid separation to obtain lithium leaching liquor and lithium leaching tailings; compared with a traditional sulfuric acid method, the method can obviously alleviate the melting and sintering phenomenon generated during the transformation roasting of high-potassium and high-phosphorus complex spodumene ore, and remarkably improves the lithium extraction efficiency; the process flow is very simple, the added additives are relatively low in price, and the method plays an extremely key and important role in efficient development and utilization of complex spodumene ore with high potassium and phosphorus contents, and has good industrial application value and popularization prospect.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of lithium ore lithium extraction, and particularly relates to a method for extracting lithium from high-potassium and high-phosphorus complex spodumene. BACKGROUND

[0002] The complex spodumene usually contains mica, eucolite and petalite, and has high contents of impurity elements such as potassium and phosphorus, which makes the extraction of lithium face many difficulties and challenges. When the traditional sulfuric acid method is used to treat such ores, problems such as agglomeration during roasting and melting on the production line and low lithium extraction rate often exist. Therefore, it is urgent to develop a new method for extracting lithium from high-potassium and high-phosphorus complex spodumene. SUMMARY

[0003] The present application aims to overcome the shortcomings of the prior art and provides a method for extracting lithium from high-potassium and high-phosphorus complex spodumene, which comprises the following steps: first, uniformly mixing high-potassium and high-phosphorus complex spodumene concentrate with additive 1 and additive 2 and then roasting to obtain roasted material; second, uniformly mixing the roasted material with appropriate sulfuric acid and then low-temperature calcining to obtain acidified material; and finally, water leaching the acidified material in water and then solid-liquid separation to obtain lithium leaching solution and lithium leaching tailings. Compared with the traditional sulfuric acid method, the method can significantly alleviate the melting and sintering phenomenon of high-potassium and high-phosphorus complex spodumene during transformation roasting, and significantly improve the extraction efficiency of lithium. The process flow proposed by the present application is very simple, the added additives are relatively inexpensive, and the method plays a crucial role in the efficient development and utilization of complex spodumene with high contents of potassium and phosphorus, and has good industrial application value and promotion prospect.

[0004] To achieve the above technical effects, the following technical solutions are adopted:

[0005] A method for extracting lithium from high-potassium and high-phosphorus complex spodumene, comprising the following steps:

[0006] Step S1: uniformly mixing high-potassium and high-phosphorus complex spodumene concentrate with additive 1 and additive 2 and then transformation roasting to obtain roasted material;

[0007] Step S2: uniformly mixing the roasted material in step S1 with sulfuric acid and then low-temperature calcining to obtain acidified material;

[0008] Step S3: water leaching the acidified material in step S2 in water and then solid-liquid separation to obtain lithium leaching solution and lithium leaching tailings, and the lithium extraction rate in the leaching solution is greater than 80%.

[0009] Further, 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%.

[0010] Further, the aid 1 is one or more of calcium oxide, calcium hydroxide, and calcium carbonate; and the aid 2 is one or more of lepidolite, iron lepidolite, calcium fluoride, sodium fluoride, and ammonium hydrogen fluoride.

[0011] Further, the aid 1 is a mixture of two components, a component is one or more of calcium oxide, calcium hydroxide, and calcium carbonate; and a component is one or more of magnesium oxide, aluminum oxide, and iron oxide; the mass ratio of the components a and b in the aid 1 is 1:2-5:1; and the aid 2 is one or more of lepidolite, iron lepidolite, calcium fluoride, sodium fluoride, and ammonium hydrogen fluoride.

[0012] Further, the mixing mass ratio of the high-potassium and high-phosphorus complex spodumene concentrate and the aid 1 is 1:0.01-1:0.1; and the mixing mass ratio of the high-potassium and high-phosphorus complex spodumene concentrate and the aid 2 is 1:0.03-1:0.50.

[0013] Further, the temperature of the transformation roasting in the step S1 is 950-1100°C; and the time of the transformation roasting in the step S1 is 30-90 min.

[0014] The roasting conditions have a very significant influence on the final lithium extraction effect. When the roasting temperature is too low or the reaction time is too short, the high-potassium and high-phosphorus complex spodumene concentrate cannot fully react with the added aid, the crystal type transformation of spodumene and the destruction of chemical bonds are not complete and insufficient, and the lithium extraction effect is reduced; when the roasting temperature is too high or the reaction time is too long, excessive energy consumption will be caused, the production cost will be increased, and some metal impurities in the ore may form complex compounds with lithium or the whole ore material may be fused and sintered, which is not conducive to the further extraction of lithium. Therefore, the temperature and reaction time of the transformation roasting should be controlled within a suitable range.

[0015] Further, the amount of sulfuric acid used for mixing the calcined material in the step S2 is 1.5-4.5 times the theoretical acid consumption when all the lithium elements in the high-potassium and high-phosphorus complex spodumene concentrate are converted into lithium sulfate; and the sulfuric acid used is concentrated sulfuric acid.

[0016] If the amount of sulfuric acid is too low, lithium cannot be completely replaced, resulting in low leaching rate of lithium; and if the amount of sulfuric acid is too high, the content of impurity elements in the lithium leaching solution will increase, the equipment corrosion will be intensified, and the production cost will be increased.

[0017] Further, the temperature of the low-temperature calcination in the step S2 is 150-300°C.

[0018] Further, the time of the low-temperature calcination in the step S2 is 10-60 min.

[0019] Controlling the calcination temperature and time in a suitable range helps to improve the replacement efficiency of hydrogen ions in sulfuric acid and lithium ions in the mineral material. If the calcination temperature is too low or the time is too short, the replacement rate of lithium will be insufficient. If the calcination temperature is too high or the time is too long, the energy consumption of calcination will increase, and the production cost will increase.

[0020] Further, the water immersion reaction conditions in step S3 are as follows: the liquid-solid ratio is 2-8 mL:1 g, the temperature is 20-80 DEG C, and the time is 30-90 min.

[0021] A suitable liquid-solid ratio can ensure that the lithium element in the mineral material is fully dissolved in the leaching solution. If the liquid-solid ratio is too low, the amount of solution is insufficient to completely dissolve the lithium in the mineral material, which will result in a decrease in the lithium extraction rate. If the liquid-solid ratio is too high, not only will the concentration of lithium in the leaching solution be too low, but the volume of the leaching solution will also increase, which will make the subsequent steps of lithium separation and purification difficult.

[0022] A suitable leaching temperature can accelerate the reaction rate of lithium dissolution from the mineral material. If the leaching temperature is too low, the lithium dissolution rate will be slow. If the leaching temperature is too high, impurities such as potassium and phosphorus in the ore may be excessively dissolved, and the energy consumption will increase.

[0023] A suitable leaching time is one of the key factors to ensure that the lithium element in spodumene is fully dissolved. If the leaching time is too short, the leaching of lithium will be insufficient and incomplete. If the leaching time is too long, the production efficiency will decrease.

[0024] The beneficial effects of the present application are as follows:

[0025] (1) The present application can effectively alleviate the melting and sintering of high-potassium and high-phosphorus complex spodumene ore during the transformation roasting, and improve the production conditions. When the traditional sulfuric acid method is used to treat high-potassium and high-phosphorus complex spodumene ore, the mineral material melts and clumps seriously on the production line during the transformation roasting. After the addition of the above-mentioned additives, the melting and sintering phenomenon of high-potassium and high-phosphorus complex spodumene ore during high-temperature roasting can be significantly alleviated, which is of great significance for improving the production conditions and increasing the production efficiency.

[0026] (2) The present application can significantly improve the leaching rate of lithium in high-potassium and high-phosphorus complex spodumene ore. When the traditional sulfuric acid method is used to treat high-potassium and high-phosphorus complex spodumene ore alone, the extraction effect of lithium is often not good, and the leaching rate is concentrated in 50-60%. After the addition of the above-mentioned additives, the activation and extraction of the mineral material are significantly improved, and the lithium leaching rate is generally greater than 80%. Under the special combination of the additives, the lithium leaching rate can be further improved to more than 95%. The lithium extraction rate obtained by the present application for treating complex spodumene ore 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 ore, improves the comprehensive utilization rate of lithium resources, reduces resource waste, and expands economic benefits.

[0027] (3) The present application reduces the temperature of the transformation roasting to some extent. When the high-potassium and high-phosphorus complex spodumene ore is treated by the traditional sulfuric acid method alone, transformation roasting at 1050°C or higher is often required to obtain a high lithium leaching rate. After the addition of the above-mentioned additives, a leaching rate better than that of the sulfuric acid method alone can be obtained at about 950-1000°C.

[0028] (4) The process used in the present application is very simple, the added additives are harmless, inexpensive and easy to obtain, and will not cause a large increase in leaching residue, the method is mature, the cost is low, and the system has strong adaptability. BRIEF DESCRIPTION OF DRAWINGS

[0029] In order to more clearly illustrate the technical solutions of the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. The drawings in the following description are only embodiments of the present application, and those skilled in the art can obtain other drawings without creative labor on the basis of the provided drawings.

[0030] Figure 1 is a process schematic diagram of the method for extracting lithium from high-potassium and high-phosphorus complex spodumene ore provided by the embodiments of the present application. DETAILED DESCRIPTION

[0031] In order to make the objects, technical solutions and advantages of the present application more clear, the following will further describe the present application in combination with embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application, and are not used to limit the present application.

[0032] It should be pointed out that the following detailed description is exemplary and is intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as generally understood by those skilled in the art to which the present application belongs.

[0033] It should be noted that the terms used herein are only for the purpose of describing specific embodiments, and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is intended to include the plural form, and in addition, it should be understood that when the terms "comprise" and / or "include" are used in the specification, it means that the features, steps, operations and / or combinations thereof are present.

[0034] Example 1:

[0035] According to the above-mentioned method, the high-potassium and high-phosphorus complex spodumene ore lithium extraction operation is carried out as shown in the following table: Figure 1

[0036] ​100g of a complex lithium spodumene concentrate with high potassium and high phosphorus content (Li content 2.33 wt.%, K content 1.36 wt.%, P content 4.22 wt.%) was uniformly mixed with 1g of calcium oxide (auxiliary agent 1) and 3g of ammonium bifluoride (auxiliary agent 2). The mixture was then placed in a muffle furnace for transformation roasting at 950°C for 90 min. After cooling to 100°C, the roasted material was ball-milled to below 100 mesh. Concentrated sulfuric acid was then added at 2.0 times the theoretical acid consumption and mixed uniformly. The acid mixture was then placed in a muffle furnace for low-temperature calcination at 150°C for 60 min to obtain an acidified material. Subsequently, the acidified material was leached in water at a liquid-to-solid ratio of 2mL:1g at 20°C for 90 min. After leaching, the mixture was filtered to obtain lithium leaching solution and lithium leaching tailings.

[0037] Analysis showed that the leaching rate of Li in the leachate obtained in Example 1 was 83.21%. After conversion roasting, the roasted sample was observed to be relatively loose, with no obvious melting or sintering phenomenon. This indicates that the proposed technical solution can achieve an ideal lithium extraction rate from complex high-potassium and high-phosphorus spodumene concentrate at relatively low energy consumption (950°C), and effectively alleviates the melting and sintering problem of complex high-potassium and high-phosphorus spodumene ore during conversion roasting.

[0038] Example 2:

[0039] according to Figure 1 As shown, lithium extraction operations are performed on complex spodumene ores with high potassium and high phosphorus content.

[0040] 100g of a complex spodumene concentrate with high potassium and high phosphorus content (Li content 2.33 wt.%, K content 1.36 wt.%, P content 4.22 wt.%) was uniformly mixed with 10g of calcium oxide (auxiliary agent 1) and 50g of lepidolite (auxiliary agent 2). The mixture was then placed in a muffle furnace for transformation roasting at 1100°C for 30 minutes. After cooling to 100°C, the roasted material was ball-milled to below 100 mesh. Concentrated sulfuric acid was then added at 4.5 times the theoretical acid consumption and mixed uniformly. The acid mixture was then placed in a muffle furnace for low-temperature calcination at 300°C for 10 minutes to obtain an acidified material. Subsequently, the acidified material was leached in water at a liquid-to-solid ratio of 8mL:1g at 80°C for 30 minutes. After leaching, the mixture was filtered to obtain lithium leachate and lithium leaching tailings.

[0041] Analysis showed that the leaching rate of Li in the leachate obtained in Example 2 was 85.05%. After conversion roasting, the roasted sample was observed to be relatively loose, with no obvious melting or sintering phenomenon. This indicates that the proposed technical solution can achieve an ideal lithium extraction rate from complex high-potassium and high-phosphorus spodumene concentrate, and effectively alleviates the melting and sintering problem of complex high-potassium and high-phosphorus spodumene ore during conversion roasting.

[0042] Example 3:

[0043] According to the technical scheme shown in FIG. 3, the lithium extraction operation of the high-potassium and high-phosphorus complex spodumene ore is carried out as follows: Figure 1

[0044] Take 100 g of high-potassium and high-phosphorus complex spodumene concentrate with Li content of 2.33 wt.%, K content of 1.36 wt.%, and P content of 4.22 wt.% and uniformly mix 3 g of auxiliary agent 1 calcium oxide and 10 g of auxiliary agent 2 calcium fluoride, and then place them in a muffle furnace for transformation roasting, with the roasting temperature set to 1000°C and the roasting time set to 60 min. After the roasted material is cooled to 100°C, it is ball milled to 100 mesh or less, and then concentrated sulfuric acid is added according to 3.0 times the theoretical acid consumption and uniformly mixed. The mixed acid material is placed in a muffle furnace for low-temperature calcination, with the calcination temperature set to 250°C and the calcination time set to 40 min, to obtain acidized material. Then, the acidized material is placed in water for water leaching according to a liquid-solid ratio of 4 mL:1 g, with the leaching temperature set to 45°C and the time set to 30 min. After leaching, filtration is performed to obtain a lithium leaching solution and a lithium leaching residue.

[0045] Through detection and analysis, the leaching rate of Li in the leaching solution obtained in Example 3 is 84.65%, and the roasted sample after transformation roasting is observed to be fluffy without obvious melting and sintering phenomenon. This indicates that the technical scheme can achieve an ideal lithium extraction rate from high-potassium and high-phosphorus complex spodumene concentrate and effectively alleviate the melting and sintering of high-potassium and high-phosphorus complex spodumene ore during transformation roasting.

[0046] Example 4:

[0047] According to the technical scheme shown in FIG. 3, the lithium extraction operation of the high-potassium and high-phosphorus complex spodumene ore is carried out as follows: Figure 1

[0048] Take 100 g of high-potassium and high-phosphorus complex spodumene concentrate with Li content of 2.33 wt.%, K content of 1.36 wt.%, and P content of 4.22 wt.% and uniformly mix 3 g of auxiliary agent 1 calcium oxide and 10 g of auxiliary agent 2 calcium fluoride, and then place them in a muffle furnace for transformation roasting, with the roasting temperature set to 1000°C and the roasting time set to 60 min. After the roasted material is cooled to 100°C, it is ball milled to 100 mesh or less, and then concentrated sulfuric acid is added according to 3.0 times the theoretical acid consumption and uniformly mixed. The mixed acid material is placed in a muffle furnace for low-temperature calcination, with the calcination temperature set to 250°C and the calcination time set to 40 min, to obtain acidized material. Then, the acidized material is placed in water for water leaching according to a liquid-solid ratio of 4 mL:1 g, with the leaching temperature set to 45°C and the time set to 30 min. After leaching, filtration is performed to obtain a lithium leaching solution and a lithium leaching residue.

[0049] ​​The detection analysis shows that the leaching rate of Li in the leaching solution obtained in Example 4 is 83.47%, and the roasted sample is fluffy after transformation roasting, and there is no obvious sintering phenomenon. It shows that the technical scheme can obtain ideal lithium extraction rate from high-potassium and high-phosphorus complex spodumene concentrate, and effectively alleviate the sintering of high-potassium and high-phosphorus complex spodumene ore during transformation roasting.

[0050] Example 5:

[0051] According to the technical scheme shown in Figure 1 , the lithium extraction operation of high-potassium and high-phosphorus complex spodumene ore is carried out as follows:

[0052] Take 100 g of high-potassium and high-phosphorus complex spodumene concentrate with Li content of 2.33 wt.%, K content of 1.36 wt.% and P content of 4.22 wt.% and 5 g of additive 1 calcium carbonate and 4 g of additive 2 sodium fluoride, mix them uniformly, and then place them in a muffle furnace for transformation roasting. The roasting temperature is set to 1000°C, and the roasting time is 60 min. After the roasted material is cooled to 100°C, it is ball milled to 100 mesh or less. Then, 3.0 times of the theoretical acid consumption of concentrated sulfuric acid is added and mixed uniformly. The mixed acid material is placed in a muffle furnace for low-temperature calcination. The calcination temperature is set to 250°C, and the calcination time is 40 min to obtain acidized material. Then, the acidized material is placed in water for water leaching according to the liquid-solid ratio of 4 mL:1 g. The leaching temperature is set to 45°C, and the time is 30 min. After leaching, filtration is performed to obtain lithium leaching solution and lithium leaching residue.

[0053] The detection analysis shows that the leaching rate of Li in the leaching solution obtained in Example 5 is 83.33%, and the roasted sample is fluffy after transformation roasting, and there is no obvious sintering phenomenon. It shows that the technical scheme can obtain ideal lithium extraction rate from high-potassium and high-phosphorus complex spodumene concentrate, and effectively alleviate the sintering of high-potassium and high-phosphorus complex spodumene ore during transformation roasting.

[0054] Example 6:

[0055] According to the technical scheme shown in Figure 1 , the lithium extraction operation of high-potassium and high-phosphorus complex spodumene ore is carried out as follows:

[0056] Take 100 g of high potassium and high phosphorus complex spodumene concentrate with Li content of 2.20 wt.%, K content of 2.12 wt.% and P content of 1.42 wt.% and 3 g of auxiliary agent 1 calcium oxide and 10 g of auxiliary agent 2 calcium fluoride, mix uniformly, then place in a muffle furnace for transformation roasting, set the roasting temperature to 1050°C, and the roasting time to 60 min. After the roasting material is cooled to 100°C, it is ball milled to 100 mesh or less, then 2.0 times the theoretical acid consumption of concentrated sulfuric acid is added and mixed uniformly, the mixed acid material is placed in a muffle furnace for low temperature calcination, the calcination temperature is set to 250°C, and the calcination time is 40 min, to obtain an acidized material. Then the acidized material is placed in water for water leaching according to a liquid to solid ratio of 4 mL:1 g, the leaching temperature is set to 45°C, and the time is 30 min. After leaching, filtration is performed to obtain a lithium leachate and a lithium leaching tailing.

[0057] Detection analysis shows that the leaching rate of Li in the leachate obtained in Example 6 is 85.73%, and after transformation roasting, the roasting sample is observed to be fluffy with no obvious melting and sintering phenomenon. This shows that the present technical solution can achieve an ideal lithium extraction rate from high potassium and high phosphorus complex spodumene concentrate, and effectively alleviate the melting and sintering of high potassium and high phosphorus complex spodumene concentrate during transformation roasting.

[0058] Comparative Example 1:

[0059] The lithium is extracted by the method of Example 1, except that only auxiliary agent 2 (4 g) is added, and the transformation roasting temperature is 800°C; the others remain the same.

[0060] Detection analysis shows that the leaching rate of Li in the leachate obtained in Comparative Example 1 is 4.38%.

[0061] Comparative Example 2:

[0062] The lithium is extracted by the method of Example 1, except that auxiliary agent 1 (1 g) and auxiliary agent 2 (3 g) are added, but the transformation roasting temperature is 800°C; the others remain the same.

[0063] Detection analysis shows that the leaching rate of Li in the leachate obtained in Comparative Example 1 is 4.68%.

[0064] Comparative Example 3:

[0065] The lithium is extracted by the method of Example 1, except that only auxiliary agent 2 (4 g) is added, and the transformation roasting temperature is 900°C; the others remain the same.

[0066] Detection analysis shows that the leaching rate of Li in the leachate obtained in Comparative Example 1 is 20.77%.

[0067] Comparative Example 4:

[0068] The method of Example 1 was adopted to extract lithium, except that the additive 1 (1 g) and the additive 2 (3 g) were added, but the temperature of the transformation roasting was 900 ℃; the others were kept unchanged.

[0069] The detection analysis showed that the leaching rate of Li in the leaching solution obtained in Comparative Example 1 was 60.39%.

[0070] Comparative Example 5:

[0071] The method of Example 1 was adopted to extract lithium, except that the additive 1 and the additive 2 were not added, and the temperature of the transformation roasting was 1000 ℃; the others were kept unchanged.

[0072] The detection analysis showed that the leaching rate of Li in the leaching solution obtained in Comparative Example 1 was 50.41%.

[0073] Comparative Example 6:

[0074] The method of Example 1 was adopted to extract lithium, except that only the additive 2 (4 g) was added, and the temperature of the transformation roasting was 1000 ℃; the others were kept unchanged.

[0075] The detection analysis showed that the leaching rate of Li in the leaching solution obtained in Comparative Example 1 was 65.23%.

[0076] Comparative Example 7:

[0077] The method of Example 1 was adopted to extract lithium, except that only the additive 1 (4 g) was added, and the temperature of the transformation roasting was 1000 ℃; the others were kept unchanged.

[0078] The detection analysis showed that the leaching rate of Li in the leaching solution obtained in Comparative Example 1 was 55.71%.

[0079] Comparative Example 8:

[0080] The method of Example 1 was adopted to extract lithium, except that the calcium oxide in the additive 1 was replaced by copper oxide (1 g), and the temperature of the transformation roasting was 1000 ℃; the others were kept unchanged.

[0081] The detection analysis showed that the leaching rate of Li in the leaching solution obtained in Comparative Example 1 was 68.49%.

[0082] Example 7:

[0083] The method of Example 3 was adopted to extract lithium, except that only the additive 1 was changed to calcium oxide 1 g and magnesium oxide 2 g, and the others were unchanged.

[0084] The detection analysis shows that the leaching rate of Li in the obtained leaching solution under the conditions of this embodiment is 96.31%, and the roasted sample is more fluffy after transformation roasting, and the melting sintering phenomenon is less obvious. Compared with Example 3, the lithium leaching effect is further improved in Example 7, indicating that the combined addition of the additive 1 is better than the single addition.

[0085] Example 8:

[0086] The method of Example 3 is used to extract lithium, except that the additive 1 is changed to calcium oxide 1.5 g and aluminum oxide 1.5 g, and the others remain unchanged.

[0087] The detection analysis shows that the leaching rate of Li in the obtained leaching solution under the conditions of this embodiment is 95.87%, and the roasted sample is more fluffy after transformation roasting, and the melting sintering phenomenon is less obvious. Compared with Example 3, the lithium leaching effect is further improved in Example 8, indicating that the combined addition of the additive 1 is better than the single addition.

[0088] Example 9:

[0089] The method of Example 3 is used to extract lithium, except that the additive 1 is changed to calcium oxide 2 g and iron oxide 1 g, and the others remain unchanged.

[0090] The detection analysis shows that the leaching rate of Li in the obtained leaching solution under the conditions of this embodiment is 95.93%, and the roasted sample is more fluffy after transformation roasting, and the melting sintering phenomenon is less obvious. Compared with Example 3, the lithium leaching effect is further improved in Example 9, indicating that the combined addition of the additive 1 is better than the single addition.

[0091] Example 10:

[0092] The method of Example 3 is used to extract lithium, except that the additive 1 is changed to calcium hydroxide 2.5 g and magnesium oxide 0.5 g, and the others remain unchanged.

[0093] The detection analysis shows that the leaching rate of Li in the obtained leaching solution under the conditions of this embodiment is 95.47%, and the roasted sample is more fluffy after transformation roasting, and the melting sintering phenomenon is less obvious. Compared with Example 3, the lithium leaching effect is further improved in Example 10, indicating that the combined addition of the additive 1 is better than the single addition.

[0094] Example 11:

[0095] The method of Example 3 is used to extract lithium, except that the additive 1 is changed to calcium hydroxide 2 g and aluminum oxide 1 g, and the others remain unchanged.

[0096] The detection analysis shows that the leaching rate of Li in the obtained leaching solution under the conditions of this embodiment is 96.14%, and the roasted sample is more fluffy after transformation roasting, and the melting sintering phenomenon is less obvious. Compared with Example 3, the lithium leaching effect is further improved in Example 11, which shows that the combined addition of additive 1 is better than the single addition.

[0097] Example 12:

[0098] The method of Example 3 is used to extract lithium, except that additive 1 is changed to calcium hydroxide 1.5 g and iron oxide 1.5 g, and the others remain unchanged.

[0099] The detection analysis shows that the leaching rate of Li in the obtained leaching solution under the conditions of this embodiment is 96.02%, and the roasted sample is more fluffy after transformation roasting, and the melting sintering phenomenon is less obvious. Compared with Example 3, the lithium leaching effect is further improved in Example 12, which shows that the combined addition of additive 1 is better than the single addition.

[0100] Comparative Example 9:

[0101] The method of Example 7 is used to extract lithium, except that additive 2 is not added, additive 1 is changed to calcium oxide 4.33 g and magnesium oxide 8.67 g. The transformation roasting temperature is 1000°C; and the others remain unchanged.

[0102] The detection analysis shows that the leaching rate of Li in the obtained leaching solution under the conditions of this embodiment is 56.84%.

[0103] Comparative Example 10:

[0104] The method of Example 7 is used to extract lithium, except that additive 1 is changed to calcium oxide 3 g and additive 2 is 10 g. That is, the technical solution of Example 3. The transformation roasting temperature is 1000°C; and the others remain unchanged.

[0105] The detection analysis shows that the leaching rate of Li in the obtained leaching solution under the conditions of this embodiment is 84.65%.

[0106] Comparative Example 11:

[0107] The method of Example 7 is used to extract lithium, except that additive 1 is changed to magnesium oxide 3 g and additive 2 is 10 g. The transformation roasting temperature is 1000°C; and the others remain unchanged.

[0108] The detection analysis shows that the leaching rate of Li in the obtained leaching solution under the conditions of this embodiment is 82.69%.

[0109] Comparative Example 12:

[0110] The method of Example 7 was used to extract lithium, except that only the calcium oxide (13 g) in Additive 1 was added, Additive 2 was not added, the transformation roasting temperature was 1000°C, and the other conditions were the same.

[0111] The leaching rate of Li in the leaching solution obtained in Comparative Example 1 was 58.51% by detection analysis.

[0112] Comparative Example 13:

[0113] The method of Example 7 was used to extract lithium, except that only the magnesium oxide (13 g) in Additive 1 was added, Additive 2 was not added, the transformation roasting temperature was 1000°C, and the other conditions were the same.

[0114] The leaching rate of Li in the leaching solution obtained in Comparative Example 1 was 56.32% by detection analysis.

[0115] Comparative Example 14:

[0116] The method of Example 7 was used to extract lithium, except that only Additive 2 (13 g) was added, the transformation roasting temperature was 1000°C, and the other conditions were the same.

[0117] The leaching rate of Li in the leaching solution obtained in Comparative Example 1 was 68.79% by detection analysis.

[0118] Comparative Example 15:

[0119] The method of Example 7 was used to extract lithium, except that the calcium oxide in Additive 1 was replaced with copper oxide, the transformation roasting temperature was 1000°C, and the other conditions were the same.

[0120] The leaching rate of Li in the leaching solution obtained in Comparative Example 1 was 80.57% by detection analysis.

[0121] Comparative Example 16:

[0122] The method of Example 7 was used to extract lithium, except that the magnesium oxide in Additive 1 was replaced with copper oxide, the transformation roasting temperature was 1000°C, and the other conditions were the same.

[0123] The leaching rate of Li in the leaching solution obtained in Comparative Example 1 was 81.37% by detection analysis.

[0124] Comparative Example 17:

[0125] The method of Example 7 was used to extract lithium, except that the amount of sulfuric acid was 1.5 times the theoretical acid consumption.

[0126] The detection analysis shows that the leaching rate of Li in the obtained leaching solution under the conditions of the embodiment is 75.50%, and the roasted sample is fluffy after transformation roasting, and no obvious melting and sintering phenomenon is observed. Compared with example 7, the lithium leaching effect is poorer, which shows that the insufficient amount of acid cannot completely complete the replacement of lithium. The additive 1 in the technical solution consumes sulfuric acid, so the amount of sulfuric acid should be properly increased or decreased according to the different amount of additive 1 added during actual implementation.

[0127] From the above experiments, it can be seen that the lithium extraction rate of high-potassium and high-phosphorus complex spodumene concentrate is greatly improved by the synergistic effect of the additive 1 and the additive 2. When the additive 1 is one or more of calcium oxide, calcium hydroxide and calcium carbonate, the lithium extraction rate of high-potassium and high-phosphorus complex spodumene concentrate can reach about 85%. When the additive 1 is a mixture of a and b components, the a component is one or more of calcium oxide, calcium hydroxide and calcium carbonate; and the b component is one or more of magnesium oxide, aluminum oxide and iron oxide, the lithium extraction rate of high-potassium and high-phosphorus complex spodumene concentrate is more than 95%. Through the synergistic effect of the components in the additive 1 and the components in the additive 2, the lithium extraction rate of high-potassium and high-phosphorus complex spodumene concentrate is greatly improved.

[0128] In summary, the application discloses a method for 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 additive 1 and additive 2, and then performing transformation roasting to obtain roasted material; secondly, uniformly mixing the roasted material with appropriate sulfuric acid and then performing low-temperature calcination to obtain acidified material; finally, placing the acidified material in water, performing water immersion, and then performing solid-liquid separation to obtain lithium leaching solution and lithium leaching tailings. Compared with the traditional sulfuric acid method, the method can obviously alleviate the melting and sintering phenomenon generated during the transformation roasting of high-potassium and high-phosphorus complex spodumene ore, and significantly improves the lithium extraction efficiency. The process flow proposed in the technical solution is very simple, the added additive is relatively low in price, plays an extremely key role in the efficient development and utilization of complex spodumene ore with high potassium and phosphorus content, and has good industrial application value and promotion prospect.

[0129] At this point, those skilled in the art realize that although the embodiments of the application have been fully demonstrated and described herein, many other variations or modifications conforming to the principles of the application can be directly determined or deduced according to the disclosure of the application without departing from the spirit and scope of the application. Therefore, the scope of the application should be understood and recognized as covering all these other variations or modifications.

Claims

1. A method for extracting lithium from a high potassium and high phosphorus complex spodumene ore, characterized in that, The lithium extraction method comprises the following steps: Step S1: uniformly mixing a high-potassium and high-phosphorus complex spodumene concentrate with an additive 1 and an additive 2, and then performing transformation roasting to obtain a roasted material; Step S2: uniformly mixing the roasted material in step S1 with sulfuric acid, and then performing low-temperature calcination to obtain an acidized material; Step S3: placing the acidized material in step S2 in water, performing water immersion, and then performing solid-liquid separation to obtain a lithium leaching solution and a lithium leaching tailing, and the lithium extraction rate in the leaching solution is greater than 80%; The additive 1 is a mixture of two components a and b, 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 additive 1 is 1:2-5:1, and the additive 2 is one or more of lepidolite, iron lepidolite, calcium fluoride, sodium fluoride and ammonium hydrogen fluoride; 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%; 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, and 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.

2. A process for the extraction of lithium from a complex spodumene ore having high potassium and high phosphorus as claimed in claim 1, characterized in that, The transformation roasting temperature in step S1 is 950-1100°C, and the transformation roasting time in step S1 is 30-90min.

3. A process for the extraction of lithium from a complex spodumene ore having high potassium and high phosphorus as claimed in claim 1, wherein, The amount of the calcined material mixed with sulfuric acid in step S2 is 1.5-4.5 times the theoretical acid consumption when all lithium elements in the high-potassium and high-phosphorus complex spodumene concentrate are converted into lithium sulfate, and the used sulfuric acid is concentrated sulfuric acid.

4. A process for the extraction of lithium from a complex spodumene ore having high potassium and high phosphorus as claimed in claim 1, characterized in that, The low-temperature calcination temperature in step S2 is 150-300°C.

5. A process for the extraction of lithium from a complex spodumene ore having high potassium and high phosphorus as claimed in claim 1, wherein, The low-temperature calcination time in step S2 is 10-60min.

6. A process for the extraction of lithium from a complex spodumene ore having high potassium and high phosphorus as claimed in claim 1, characterized in that, The water immersion reaction conditions in step S3 are as follows: the liquid-solid ratio is 2-8mL:1g, the temperature is 20-80°C, and the time is 30-90min.

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