Method for extracting lithium through synergistic suspension roasting, cooling and activation of clay type lithium ore-spodumene

Abstract

The invention provides a clay-type lithium ore-spodumene synergistic suspension roasting cooling activation lithium extraction method, which comprises the following steps: carrying out crushing and grinding, waste throwing pretreatment and flotation impurity removal on clay-type lithium ore, mixing with spodumene concentrate, carrying out synergistic suspension roasting, cooling, adding concentrated sulfuric acid, carrying out low-temperature acidification roasting, and finally carrying out water leaching. And lithium leaching liquid is obtained. The leaching rate of lithium in the lithium leachate obtained through the lithium extraction method is larger than or equal to 90%. According to the method, the aims of effectively reducing the spodumene crystal transformation roasting temperature, shortening the clay type lithium ore roasting time and improving the economic benefits of clay type lithium ore utilization and extraction are achieved, the technological process is simple, energy consumption and cost are low, industrial production is easy, and the method has good application prospects.

Description

Technical Field

[0001] The invention belongs to the technical field of mineral processing, and in particular relates to a method for extracting lithium by collaborative suspension roasting, cooling and activation of clay-type lithium ore and spodumene. Background Art

[0002] Lithium resources are a vital raw material for a wide range of industries, widely used in automotive, aerospace, batteries, pharmaceuticals, and other sectors. In recent years, due to the huge demand from the battery industry, lithium resource consumption has shown a sharp increase. Lithium resources are primarily categorized into three types: salt lake brine, granite pegmatite, and sedimentary carbonate (clay) types. However, the majority of my country's lithium resources are concentrated in geographically harsh areas such as northern Xinjiang, western Sichuan, and the Qinghai-Tibet Plateau, where harsh natural environments and inadequate infrastructure are common. Consequently, my country's lithium resources have yet to be fully and effectively developed, and the country has long relied on imports of lithium ore, with an external dependence rate exceeding 70%. This situation highlights the need for the exploration and effective development of lithium resources.

[0003] Spodumene has three phase structures: α, β and γ. Lithium in nature mainly exists in the form of α-type spodumene, which has stable chemical properties and is difficult to react with acids and bases at room temperature and pressure. + Filled between silicon-oxygen tetrahedra and aluminum-oxygen octahedra. Currently, spodumene extraction technologies are mainly divided into sulfuric acid roasting, sulfate roasting, lime sintering, alkaline pressure cooking, chloride roasting, and fluorine chemical methods, which are suitable for different ore characteristics and production needs. Under high temperature conditions, the α-type spodumene crystal form will transform into β-type spodumene. Compared with α-type spodumene, β-type spodumene has a looser structure and higher chemical activity. Therefore, the mainstream lithium extraction process from spodumene requires first transforming the α-type spodumene crystal form into β-type spodumene before extracting lithium. However, the crystal transformation roasting of spodumene requires a temperature of ≥1050°C to achieve the ideal effect, and this process urgently needs to solve the problem of extremely high energy consumption.

[0004] Clay-type lithium ore, a reserve resource, is often considered unusable due to its low grade and fine particle size. Furthermore, the extraction process for clay-type lithium ore presents challenges such as large processing volumes, large slag volumes, and low extraction efficiency. The development and utilization of clay-type lithium ore is constrained by its complex occurrence and difficult extraction process, resulting in high economic costs for its sole mining. Currently, the primary processing method for clay-type lithium ore is the roasting-leaching process. Patent CN118880064A discloses a method for low-temperature, acid-free leaching of lithium from clay-type lithium ore, which reduces the roasting temperature and leaching temperature, achieving low-temperature, acid-free leaching with a roasting temperature of 400-450°C and a leaching temperature of 45-75°C; Patent CN118724030A discloses an invention for preparing lithium carbonate by a roasting-leaching method using carbonate clay-type lithium ore as a test object; Patent CN118880063A discloses a method using concentrated sulfuric acid as a roasting aid for clay-type lithium ore, with a lithium leaching rate of over 70%; All of the above technologies demonstrate that the use of a suitable roasting aid can effectively promote the leaching of lithium from clay-type lithium ore under the roasting-leaching method. However, the roasting object of the above-mentioned clay-type lithium ore is a single clay-type lithium ore, and there is currently no large-scale industrial production and utilization. According to lithium price statistics for 2024, the price of industrial-grade lithium carbonate is approximately 75,000 yuan / ton, while the production cost of lithium carbonate extracted from clay-type lithium ore is approximately 160,000 yuan / ton. This significant cost-price disparity makes it unsuitable for current mining economic activities. Based on the current status of lithium ore utilization, co-roasting of lithium ore is currently an effective solution for the utilization of clay-type lithium ore.

[0005] Patent CN118639032A proposes a method for the coordinated roasting of spodumene and lepidolite, which reduces the roasting temperature of spodumene to 800-950°C while effectively extracting and utilizing lepidolite. However, as the mining of spodumene and lepidolite increases, the grade of the above two lithium mineral resources is gradually deteriorating (grade reduction). In addition, clay-type lithium ore, as an important lithium mineral reserve resource, is currently not produced on a large scale in China. Therefore, it is of great significance to plan the utilization of clay-type lithium mineral resources in advance.

[0006] Therefore, the present invention develops a lithium extraction technology based on clay-type lithium ore and spodumene, which is economically feasible, easy to practice, and has a high lithium recovery rate, and is conducive to the rapid development of the lithium mining industry. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to address the deficiencies of the above-mentioned prior art and provide a method for extracting lithium by co-suspension roasting of clay-type lithium ore and spodumene, wherein the clay-type lithium ore and spodumene concentrate, which have undergone crushing, grinding, waste pretreatment, and flotation decontamination, are co-suspension roasted, followed by low-temperature sulfation roasting and water leaching to obtain a lithium leachate. The present invention reduces the crystallization roasting temperature, the acidification roasting temperature, the amount of acidification used, and the roasting time, thereby reducing energy consumption and cost, facilitating industrial production, and having good application prospects.

[0008] To solve the above technical problems, the present invention adopts a technical solution: a method for extracting lithium from clay-type lithium ore-spodumene by coordinated suspension roasting, cooling and activation, comprising the following steps: S1, crushing and grinding the clay-type lithium ore, and then performing waste pretreatment and flotation to remove impurities to obtain a clay-type lithium ore sample; S2, mixing the clay-type lithium ore sample obtained in S1 with spodumene concentrate and then performing high-temperature roasting to obtain a high-temperature roasted material; S3, the high temperature roasting material obtained in S2 is air cooled to below 80 ° C, concentrated sulfuric acid is added and mixed uniformly, and the mixture is subjected to low temperature acidification roasting to obtain an acidified roasting material; S4. Leaching the acidified roasted material obtained in S3 into water to obtain a lithium leaching solution.

[0009] Preferably, the lithium content of the clay-type lithium ore is 0.1-0.6 wt.%, and the lithium content of the spodumene concentrate is 1.5-3.5 wt.%.

[0010] Preferably, the proportion of particles with a particle size of -0.074 mm in the clay-type lithium ore sample described in S1 is greater than 70%.

[0011] Preferably, the mass ratio of the clay-type lithium ore sample to the spodumene concentrate in S2 is (2-1): (3-1).

[0012] Preferably, the high temperature roasting temperature in S2 is 825°C to 925°C, and the roasting time is 15 min to 60 min.

[0013] Preferably, the mass concentration of the concentrated sulfuric acid in S3 is 18.4 mol / L, and the amount of concentrated sulfuric acid used is 1.1 to 1.3 times the theoretical acid consumption when all the lithium elements in the clay-type lithium ore and spodumene concentrate are converted into lithium sulfate.

[0014] Preferably, the low-temperature acidification calcination temperature in S3 is 100° C. to 150° C., and the calcination time is 10 min to 20 min.

[0015] Preferably, the leaching temperature in the water leaching process in S4 is 20°C~50°C, the leaching time is 30min~60min, and the liquid-solid ratio is (3~5):1.

[0016] Preferably, the leaching rate of lithium in the lithium leaching solution in S4 is ≥90%.

[0017] Compared with the prior art, the present invention has significant technical effects: 1. The present invention provides a method for extracting lithium by collaborative suspension roasting, cooling and activation of clay-type lithium ore and spodumene. The clay-type lithium ore and spodumene concentrate after crushing-grinding-waste pretreatment-flotation and impurity removal are collaboratively suspended roasted, followed by low-temperature sulfuric acid roasting and water leaching. Finally, a lithium leaching rate of ≥90% in the lithium leachate is obtained, thereby achieving the purpose of effectively reducing the spodumene crystallization roasting temperature, reducing the roasting time of clay-type lithium ore, and improving the economic benefit of the utilization and extraction of clay-type lithium ore.

[0018] 2. Lepidolite is a typical layered silicate mineral with a high degree of crystallization and an ordered structure. Clay-type lithium ores, on the other hand, contain mineral structures with interlayer domains, which are less crystalline and easily damaged, making them susceptible to calcination and leaching. Compared to the lepidolite-spodumene system, the present invention uses clay-type lithium ores and spodumene as the raw materials for the co-suspension calcination. Due to the structural differences between lepidolite and clay-type lithium ores, the clay-type lithium ores significantly lower the crystallization calcination temperature of spodumene (1050°C) and achieve ideal calcination results at lower acidification temperatures, facilitating subsequent lithium leaching.

[0019] 3. The present invention utilizes the characteristics of efficient mass and heat transfer of suspension roasting, and the roasting time is significantly shortened compared with the conventional roasting method of clay-type lithium ore, with the time reduction ratio being about 20-30%. In addition, compared with the lepidolite-spodumene system, the subsequent acidification roasting temperature of the clay-type lithium ore-spodumene system is lower, and the low-temperature acidification roasting time is shorter.

[0020] 4. The process flow of the present invention is simple, the energy consumption and cost per unit processing volume are low, the amount of acid used is small, the properties of the leached residue are easy to control, and the water leaching method is easy for industrial production, and has good application prospects.

[0021] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a process flow chart of the clay-type lithium ore-spodumene collaborative suspension roasting, cooling activation and lithium extraction process of the present invention. DETAILED DESCRIPTION

[0023] The clay-type lithium ore used in the present invention has a lithium content of 0.1-0.6 wt.%, which is a low-grade reserve lithium ore with low economic benefits if mined alone. The clay-type lithium ore is obtained through processes such as crushing-grinding-waste pretreatment-flotation and impurity removal. The waste disposal process can be a cyclone classifier, shaking table classification or heavy medium classification. The purpose of flotation and impurity removal is to enrich the clay-type minerals containing lithium and remove gangue minerals (such as quartz) in the clay-type lithium ore.

[0024] The lithium content of spodumene concentrate is 1.5~3.5 wt.%.

[0025] The mass concentration of concentrated sulfuric acid is 18.4 mol / L. The amount of concentrated sulfuric acid used is 1.1 to 1.3 times the theoretical acid consumption when all the lithium elements in clay-type lithium ore and spodumene concentrate are converted into lithium sulfate (based on the test grade of each lithium ore).

[0026] Example 1 This embodiment describes a method for extracting lithium from a clay-type lithium ore and spodumene by synergistic suspension roasting followed by cooling and activation. The clay-type lithium ore is a clay-type lithium ore from southwestern Sichuan Province, and its main chemical components are: Li2O 0.25%, SiO2 24.62%, Al2O3 53.87%, Fe2O3 1.29%, CaO 0.38%, TiO2 0.22%, MgO 0.18%, and K2O 0.04%. The method comprises the following steps: S1. After crushing and grinding the clay-type lithium ore, the ore is subjected to cyclone classification and discarded. At the same time, the classified clay-type lithium ore sample is subjected to flotation to remove gangue minerals (such as quartz) to obtain an ore sample with a particle size of -0.074 mm accounting for 71.56%; S2, the clay type lithium ore sample obtained by S1 are mixed with spodumene concentrate and then subjected to high temperature roasting. The mass ratio of the clay type lithium ore sample and spodumene concentrate is 1:1, and the roasting temperature is 925 ° C, and the roasting time is 15 min, thereby obtaining the high temperature roasting material. S3, the high temperature roasting material air obtained by S2 is cooled to below 80 ℃, the concentrated sulfuric acid is added and mixed, the consumption of the concentrated sulfuric acid is 1.3 times of theoretical acid consumption, and the mixture is placed in a muffle furnace and carried out low temperature acidification roasting, the low temperature acidification roasting temperature is 150 ℃, and roasting time is 20 min, obtains the acidified roasting material; S4, the acidified roasted material obtained in S3 was subjected to water leaching, the leaching temperature was 25 ° C, the leaching time was 40 min, the liquid-solid ratio was 4: 1, and after leaching, a leachate with a lithium leaching rate of 96.42% was obtained.

[0027] Example 2 The raw materials and method were the same as in Example 1, except that the roasting temperature in step S2 was 825°C and the roasting time was 60 min, resulting in a leachate with a lithium leaching rate of 90.39%. The reason for the reduced lithium leaching rate is that the crystallization temperature of spodumene during the coordinated suspension roasting process is relatively low, resulting in a relatively poor crystallization roasting effect.

[0028] Example 3 The raw materials and methods were the same as in Example 1, except that the roasting time in step S2 was 60 minutes, resulting in a leachate with a lithium extraction rate of 94.29%. The lithium extraction rate was not much different from that in Example 1, indicating that a roasting time of 15 minutes can achieve a good effect of clay-type lithium ore-spodumene synergistic suspension roasting.

[0029] Example 4 This embodiment describes a method for extracting lithium from a clay-type lithium ore and spodumene by synergistic suspension roasting, cooling, activation, and extraction. The clay-type lithium ore is a clay-type lithium ore from a location in Yunnan Province, and its main chemical components are: Li2O 0.18%, SiO2 39.68%, Al2O3 41.53%, Fe2O3 4.32%, CaO 0.36%, MgO 0.31%, and K2O 0.13%. The method comprises the following steps: S1. After crushing and grinding the clay-type lithium ore, the ore is discarded by shaking table classification. At the same time, the classified clay-type lithium ore sample is flotated to remove gangue minerals (such as quartz) to obtain an ore sample with a particle size of -0.074 mm accounting for 89.75%; S2, the clay type lithium ore sample obtained by S1 is mixed with spodumene concentrate and then subjected to high temperature roasting. The mass ratio of the clay type lithium ore sample and spodumene concentrate is 1:3, the roasting temperature is 880 ° C, and the roasting time is 60 min, thereby obtaining the high temperature roasting material. S3, the high temperature roasting material air obtained by S2 is cooled to below 80 ℃, the concentrated sulfuric acid is added and mixed, the consumption of the concentrated sulfuric acid is 1.1 times of theoretical acid consumption, and the mixture is placed in a muffle furnace and carried out low temperature acidification roasting, the low temperature acidification roasting temperature is 150 ℃, and roasting time is 20 min, obtains the acidified roasting material; S4, the acidified roasted material obtained in S3 was subjected to water leaching, the leaching temperature was 35 ° C, the leaching time was 40 min, and the liquid-solid ratio was 4.5: 1, to obtain a leachate with a lithium leaching rate of 90.74%.

[0030] Example 5 This embodiment describes a method for extracting lithium from a clay-type lithium ore and spodumene by synergistic suspension roasting, followed by cooling and activation. The clay-type lithium ore is a clay-type lithium ore from a location in Guizhou Province, and its main components are: Li2O 0.51%, SiO2 37.86%, Al2O3 43.58%, Fe2O3 1.49%, CaO 0.95%, TiO2 1.81%, MgO 0.44%, K2O 1.59%, and Na2O 0.33%. The method comprises the following steps: S1. After crushing and grinding the clay-type lithium ore, the ore is subjected to cyclone classification and discarded. At the same time, the classified clay-type lithium ore sample is subjected to flotation to remove gangue minerals (such as quartz) to obtain a sample with a particle size of -0.074 mm, accounting for 76.35%; S2, the clay type lithium ore sample obtained by S1 are mixed with spodumene concentrate and then subjected to high temperature roasting. The mass ratio of the clay type lithium ore sample and spodumene concentrate is 1:3, and the roasting temperature is set at 900 ° C, and the roasting time is 40 min, thereby obtaining the high temperature roasting material. S3, the high temperature roasting material air obtained by S2 is cooled to below 80 ℃, add the concentrated sulfuric acid and mix, the consumption of the concentrated sulfuric acid is 1.3 times of theoretical acid consumption, and the mixture is placed in a muffle furnace and carried out low temperature acidification roasting, the low temperature acidification roasting temperature is 150 ℃, and roasting time is 15 min, obtains the acidified roasting material; S4, the acidified roasted material obtained in S3 was subjected to water leaching, the leaching temperature was 20 ° C, the leaching time was 60 min, the liquid-solid ratio was 5: 1, and a leachate with a lithium leaching rate of 95.74% was obtained.

[0031] Example 6 This embodiment is a method for extracting lithium from a clay-type lithium ore and spodumene by synergistic suspension roasting, cooling, activation, and extraction. The clay-type lithium ore is a clay-type lithium ore from a foreign country, and its main components are Li2O 0.89%, SiO2 53.02%, Al2O3 5.77%, Fe2O33.57%, CaO 2.95%, MgO 14.05%, and K2O 4.21%. It is a typical low-aluminum, high-magnesium volcanic rock-type clay-type lithium ore. The method comprises the following steps: S1. After crushing and grinding the clay-type lithium ore, the ore is subjected to heavy medium classification and discarded. At the same time, the classified clay-type lithium ore sample is subjected to flotation to remove gangue minerals (such as quartz) to obtain a sample with a particle size of -0.074 mm, accounting for 80.96%; S2, the clay type lithium ore sample obtained by S1 are mixed with spodumene concentrate and then subjected to high temperature roasting. The mass ratio of the clay type lithium ore sample and spodumene concentrate is 2:3, the roasting temperature is 925 ° C, and the roasting time is 30 min, thereby obtaining the high temperature roasting material. S3, the high temperature roasting material air obtained by S2 is cooled to below 80 ℃, the concentrated sulfuric acid is added and mixed, the consumption of the concentrated sulfuric acid is 1.3 times of the theoretical acid consumption, and the mixture is placed in a muffle furnace and carried out low temperature acidification roasting, the low temperature acidification roasting temperature is 150 ℃, and the roasting time is 10 min, obtains the acidified roasting material; S4, the acidified roasted material obtained in S3 was subjected to water leaching, the leaching temperature was 50 ° C, the leaching time was 30 min, and the liquid-solid ratio was 3: 1, to obtain a leachate with a lithium leaching rate of 97.74%.

[0032] Example 7 The raw materials and methods are the same as those in Example 6, except that in step S2, the mass ratio of the clay-type lithium ore sample to the spodumene concentrate is 2:1, and a leachate with a lithium leaching rate of 94.21% is finally obtained, indicating that the increase in mass during the roasting process of low-grade clay-type lithium ore will slightly reduce the lithium leaching rate.

[0033] Example 8 The raw materials and methods are the same as those in Example 6, except that the low-temperature acidification roasting temperature in step S3 is 120° C., and a leachate with a lithium leaching rate of 93.02% is finally obtained, which shows that the low-temperature acidification temperature has a great influence on the roasting effect of clay-type lithium ore - spodumene.

[0034] Example 9 The raw materials and method are the same as those in Example 6, except that the low-temperature acidification and roasting temperature in step S3 is 100°C, and the final lithium leaching rate of the obtained leachate is 90.47%, indicating that within the appropriate temperature range, the higher the low-temperature acidification temperature, the better the lithium leaching rate.

[0035] Comparative Example 1 The raw materials and methods are the same as those in Example 1, except that the crystallization roasting temperature of spodumene in step S2 is 775°C, and the final lithium leaching rate is only 78.69%, which shows that the crystallization temperature has a great influence on the crystallization effect of spodumene, that is, the crystallization rate of spodumene is low at low temperatures.

[0036] The present invention provides a method for extracting lithium by co-suspension roasting, cooling and activation of clay-type lithium ore and spodumene. The clay-type lithium ore and spodumene concentrate that have undergone crushing-grinding-waste pretreatment-flotation and impurity removal are co-suspended and roasted, followed by low-temperature sulfuric acid roasting and water leaching. Finally, a leachate with a lithium leaching rate of ≥90% is obtained. Among them, the roasting temperature in the high-temperature roasting-low-temperature acidification roasting is one of the key factors affecting the lithium leaching rate. Compared with the lepidolite-spodumene system, the present invention has a lower crystallization roasting temperature, a lower acidification roasting temperature, a reduced acidification dosage, and a reduced roasting time. It has low energy consumption and cost, is easy to industrially produce, and has good application prospects.

[0037] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any way. Any simple modification, change and equivalent variation made to the above embodiment based on the essence of the invention technology shall still fall within the scope of protection of the technical solution of the present invention.

Claims

1. A method for extracting lithium from clay-type lithium ore-spodumene by coordinated suspension roasting, cooling and activation, characterized in that: The following steps are involved: S1, crushing and grinding the clay-type lithium ore, and then performing waste pretreatment and flotation to remove impurities to obtain a clay-type lithium ore sample; S2, mixing the clay-type lithium ore sample obtained in S1 with the spodumene concentrate and then performing high-temperature roasting to obtain a high-temperature roasted material; S3, the high temperature roasting material obtained in S2 is air cooled to below 80 ° C, concentrated sulfuric acid is added and mixed uniformly, and the mixture is subjected to low temperature acidification roasting to obtain an acidified roasting material; S4. Leaching the acidified roasted material obtained in S3 into water to obtain a lithium leaching solution.

2. The method according to claim 1, characterized in that The clay-type lithium ore described in S1 has a lithium content of 0.1-0.6 wt.%.

3. The method according to claim 1, characterized in that In the clay-type lithium ore sample described in S1, particles with a particle size of -0.074 mm account for more than 70%.

4. The method according to claim 1, wherein The lithium content of the spodumene concentrate described in S2 is 1.5-3.5 wt.%.

5. The method according to claim 1, wherein The mass ratio of the clay-type lithium ore sample to the spodumene concentrate described in S2 is (2~1):(3~1).

6. The method according to claim 1, characterized in that The high temperature calcination temperature in S2 is 825°C to 925°C, and the calcination time is 15 min to 60 min.

7. The method according to claim 1, characterized in that The mass concentration of the concentrated sulfuric acid in S3 is 18.4 mol / L, and the amount of concentrated sulfuric acid used is 1.1 to 1.3 times the theoretical acid consumption when all the lithium elements in the clay-type lithium ore and spodumene concentrate are converted into lithium sulfate.

8. The method according to claim 1, characterized in that The low-temperature acidification calcination temperature in S3 is 100°C to 150°C, and the calcination time is 10 min to 20 min.

9. The method according to claim 1, characterized in that The leaching temperature in the water leaching process described in S4 is 20°C~50°C, the leaching time is 30min~60min, and the liquid-solid ratio is (3~5):

1.

10. The method according to claim 1, characterized in that The leaching rate of lithium in the lithium leaching solution described in S4 is ≥90%.

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