Lithium carbonate preparation method and system based on lepidolite

Abstract

The application discloses a lithium mica-based lithium carbonate preparation method and system, and the lithium mica-based lithium carbonate preparation method comprises the following steps: obtaining lithium mica; roasting the lithium mica; dissolving the roasted lithium mica by using a solvent, and extracting lithium carbonate precipitate from a mixture obtained by dissolving; performing drying treatment on the lithium carbonate precipitate by using hot air circulating through an air duct, and adjusting the temperature and flow of the hot air according to a preset threshold; and crushing the lithium carbonate precipitate subjected to the drying treatment to obtain lithium carbonate powder. The application can save energy required for preparing lithium carbonate.

Description

Technical Field

[0001] This application relates to the field of industrial chemical preparation technology, specifically to a method and system for preparing lithium carbonate based on lepidolite. Background Technology

[0002] With the continuous development of electric vehicles and energy storage systems, the demand for high-quality battery-grade lithium carbonate is increasing. Currently, lithium carbonate is mainly extracted from lepidolite, a lithium mineral raw material. In China, the primary method for extracting lithium from lepidolite is the sulfuric acid roasting and impregnation method. In this method, the lepidolite raw material needs to undergo multiple processes and requires acidic chemicals to extract lithium carbonate. However, existing methods for preparing lithium carbonate from lepidolite are relatively outdated and energy-intensive. Summary of the Invention

[0003] Therefore, this application provides a method and system for preparing lithium carbonate based on lepidolite, which can save the energy required for preparing lithium carbonate.

[0004] This application provides a method for preparing lithium carbonate based on lepidolite, comprising:

[0005] Obtaining lepidolite;

[0006] The lepidolite is calcined;

[0007] The calcined lepidolite was dissolved using a solvent, and lithium carbonate precipitate was extracted from the resulting mixture.

[0008] The lithium carbonate precipitate is dried by circulating hot air through an air duct, and the temperature and flow rate of the hot air are adjusted according to a preset threshold.

[0009] The dried lithium carbonate precipitate is pulverized to obtain lithium carbonate powder.

[0010] Optionally, the process of obtaining lepidolite includes:

[0011] After obtaining the lepidolite, the lepidolite is crushed to obtain multiple lepidolite fragments;

[0012] Based on a preset particle size value, the multiple lithium mica fragments are screened to obtain screened lithium mica.

[0013] Optionally, the step of drying the lithium carbonate precipitate by circulating hot air through an air duct, and adjusting the temperature and flow rate of the hot air according to a preset threshold, includes:

[0014] When the lithium carbonate precipitate is dried using the hot air, the degree of dryness of the lithium carbonate precipitate is determined based on its moisture content.

[0015] When the degree of dryness of the lithium carbonate precipitate reaches the preset standard value, the temperature and flow rate of the hot air are adjusted, and the heat of the hot air during the adjustment process is obtained by using a heat exchanger to recover the heat of the hot air.

[0016] Optionally, adjusting the flow rate of the hot air includes:

[0017] Based on the preset standard values, the target wind speed and target air pressure of the hot air are determined;

[0018] The current wind speed and current air pressure of the hot air are obtained through sensor components;

[0019] The current wind speed is adjusted to the target wind speed by adjusting the rotational speed of the fan in the air duct, and the current air pressure is adjusted to the target air pressure by adjusting the dampers and valves in the air duct.

[0020] Optionally, the step of drying the lithium carbonate precipitate by circulating hot air through an air duct, and adjusting the temperature and flow rate of the hot air according to a preset threshold, further includes:

[0021] Using Bernoulli's equation, the relationship between wind speed, air pressure, and altitude at each cross-section of the duct is determined;

[0022] Based on the relationship between wind speed, air pressure and height at each cross-section of the duct, the regions in the duct that generate local resistance and friction are identified, and the energy loss value of the hot air when passing through the regions is determined.

[0023] The air duct is adjusted based on the energy loss value.

[0024] Optionally, the step of pulverizing the dried lithium carbonate precipitate to obtain lithium carbonate powder includes:

[0025] The dried lithium carbonate precipitate is pulverized using an airflow.

[0026] The flow rate and pressure of the airflow are adjusted to regulate the crushing force and obtain lithium carbonate powder of a preset particle size.

[0027] Optionally, the step of pulverizing the dried lithium carbonate precipitate to obtain lithium carbonate powder further includes:

[0028] Multiple simulated grinding chambers are generated;

[0029] The optimal grinding efficiency for each simulated grinding chamber is determined by adjusting the indoor conditions of each simulated grinding chamber.

[0030] The optimal pulverization efficiency of each of the simulated pulverizing chambers is compared to determine the optimal simulated pulverizing chamber, which serves as a design template for pulverizing chambers used to pulverize the lithium carbonate precipitate.

[0031] Optionally, adjusting the flow rate and pressure of the airflow to regulate the pulverizing force and obtain lithium carbonate powder of a preset particle size further includes:

[0032] Obtain the geometric parameters of the simulated pulverizing chamber, the physical parameters of the dried lithium carbonate precipitate, and the airflow parameters;

[0033] Based on the geometric parameters, physical parameters, and airflow parameters, the motion of the dried lithium carbonate precipitate during pulverization in the simulated pulverization chamber is simulated to obtain simulation results.

[0034] Adjust the geometric parameters or the airflow parameters until the optimal simulation result is obtained;

[0035] Based on the optimal simulation results, the flow rate, air pressure, and rate at which the dried lithium carbonate precipitate enters the pulverizing chamber are adjusted to regulate the pulverizing force and obtain lithium carbonate powder with a preset particle size.

[0036] Optionally, the method for preparing lithium carbonate based on lepidolite further includes:

[0037] Obtain the physical parameters of the dried lithium carbonate precipitate;

[0038] Based on the physical parameters, determine the energy required to pulverize each unit of the lithium carbonate precipitate;

[0039] Under the condition of achieving the energy, the operating parameters of the lithium carbonate precipitate are adjusted and the energy consumption value of the pulverization process is determined until the optimal energy consumption value is obtained. The operating parameters include at least the airflow speed, air pressure and ambient temperature.

[0040] Accordingly, this application provides a lithium carbonate preparation system based on lepidolite, comprising:

[0041] Acquisition unit, used to acquire lepidolite;

[0042] A calcination unit is used to calcine the lepidolite;

[0043] The reaction unit is used to dissolve calcined lepidolite using a solvent and extract lithium carbonate precipitate from the resulting mixture.

[0044] The drying unit is used to dry the lithium carbonate precipitate by circulating hot air through the air duct, and to adjust the temperature and flow rate of the hot air according to a preset threshold.

[0045] The pulverizing unit is used to pulverize the dried lithium carbonate precipitate to obtain lithium carbonate powder.

[0046] This application provides a method and system for preparing lithium carbonate based on lepidolite. First, lepidolite is obtained. Second, the lepidolite is calcined. Next, the calcined lepidolite is dissolved using a solvent, and lithium carbonate precipitate is extracted from the resulting mixture. Then, the lithium carbonate precipitate is dried using hot air circulating through an air duct, with the temperature and flow rate of the hot air controlled according to a preset threshold. Finally, the dried lithium carbonate precipitate is pulverized to obtain lithium carbonate powder. In the drying step, this application uses hot air circulating in an air duct to continuously dry the lithium carbonate precipitate, reducing heat loss and saving energy consumed in heating the air. Simultaneously, controlling the temperature and flow rate of the hot air according to a preset threshold satisfies the drying requirements while avoiding energy waste caused by excessively high temperatures and flow rates, thus reducing energy consumption in the lithium carbonate preparation process. Attached Figure Description

[0047] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0048] Figure 1 A schematic flowchart of a method for preparing lithium carbonate based on lepidolite provided in this application embodiment;

[0049] Figure 2 This is a schematic diagram of the structure of a lithium carbonate preparation system based on lepidolite, provided in an embodiment of this application. Detailed Implementation

[0050] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application. In the absence of conflict, the following embodiments and their technical features can be combined with each other.

[0051] Please see Figure 1This application provides a method for preparing lithium carbonate based on lepidolite, comprising:

[0052] S1. Obtain lepidolite.

[0053] In some embodiments, low-grade lepidolite is selected as the raw material, requiring that the lithium content, impurity type, and content meet specific standards.

[0054] Optionally, step S1 includes:

[0055] After obtaining lepidolite, it is crushed to obtain multiple lepidolite fragments; based on a preset particle size value, the multiple lepidolite fragments are screened to obtain screened lepidolite.

[0056] In this embodiment, the lithium mica raw material is crushed and sieved to ensure uniform particle size distribution, thereby improving calcination efficiency.

[0057] S2. Calcining of lepidolite.

[0058] Optionally, a blue-light-connected furnace can be used to calcine low-grade lepidolite, thereby converting it into soluble lithium salts. The advantage of the blue-light-connected furnace lies in its optimized internal structure, ensuring uniform heat distribution. When calcining low-grade lepidolite using this furnace, controlling the heat source temperature and distribution ensures the uniformity and stability of the calcination process.

[0059] In particular, during the calcination of lepidolite, the preferred calcination temperature range is 800℃ to 1000℃.

[0060] Furthermore, after calcination, the material is slowly cooled in a controlled environment to avoid damage to the crystal structure of the calcined lepidolite due to rapid cooling. The cooled material is then separated and screened to filter out large solid particles and unreacted substances.

[0061] S3. Using a solvent, the calcined lepidolite is dissolved, and lithium carbonate precipitate is extracted from the resulting mixture.

[0062] In this embodiment, firstly, a suitable solvent is selected, which can be water or an acidic solution, to improve the dissolution efficiency of lithium. Secondly, the calcined material is mixed with the solvent and stirred thoroughly to improve the dissolution rate of lithium. Next, the dissolved mixture is filtered to separate the lithium-containing solution and purified to remove impurities. Then, by controlling the temperature and pH value, the lithium salt is precipitated in the lithium-containing solution to form lithium carbonate precipitate.

[0063] S4. Hot air is circulated through the air duct to dry the lithium carbonate precipitate, and the temperature and flow rate of the hot air are adjusted according to a preset threshold.

[0064] In some embodiments, before performing the drying process, the wet precipitate needs to be pretreated, namely, the wet lithium carbonate and sodium sulfate mixture obtained from the precipitation is homogeneous in mass, and the moisture content of the wet material is accurately measured to determine the required degree of drying.

[0065] In this embodiment, a hot air circulation system is used to dry the lithium carbonate precipitate to ensure uniform drying of the material and avoid local overheating or undried conditions.

[0066] Preferably, the drying temperature range is 120°C to 150°C, which helps prevent the lithium carbonate material from decomposing due to heat and thus reducing its quality.

[0067] Understandably, when using hot air to dry lithium carbonate precipitates, heating is required to control the temperature. The heating source can be a natural gas burner, an electric heater, or a steam heat exchanger. A fan and air duct are also needed to circulate the hot air in the air duct, thereby drying the lithium carbonate precipitates during the flow of the hot air.

[0068] Specifically, first, the heat source and fan are started to generate hot air at the required temperature. Then, the temperature and flow rate of the hot air are adjusted by the control system to meet the specific requirements of the drying process. Then, during the drying process of lithium carbonate precipitate using hot air, the temperature and humidity of the hot air are monitored in real time to ensure the drying effect and the efficiency of the drying process.

[0069] Optionally, the steps of adjusting the hot air flow rate include:

[0070] Based on preset standard values, the target wind speed and target air pressure of the hot air are determined; the current wind speed and current air pressure of the hot air are obtained through sensor components; the current wind speed is adjusted to the target wind speed by adjusting the speed of the fan in the air duct, and the current air pressure is adjusted to the target air pressure by adjusting the dampers and valves in the air duct.

[0071] Furthermore, when the wind speed or air pressure exceeds the preset safety range, an alarm is issued, and the wind speed is automatically reduced or the pressure is adjusted when an anomaly is detected.

[0072] In this embodiment, by effectively controlling the wind speed and air pressure in the hot air circulation system, drying efficiency is improved, energy consumption is reduced, and the stability and safety of the system are ensured.

[0073] Optionally, step S4 includes:

[0074] When using hot air to dry lithium carbonate precipitate, the degree of dryness of the lithium carbonate precipitate is determined based on its moisture content. When the degree of dryness of the lithium carbonate precipitate reaches the preset standard value, the temperature and flow rate of the hot air are adjusted, and the heat generated by the hot air during the adjustment process is obtained by using a heat exchanger to recover the heat of the hot air.

[0075] Optionally, step S4 further includes:

[0076] Using Bernoulli's equation, the relationship between wind speed, air pressure, and altitude at each cross-section of the duct is determined. Based on this relationship, the regions in the duct that generate local resistance and friction are identified, and the energy loss value of hot air passing through these regions is determined. Based on the energy loss value, the duct is adjusted.

[0077] In this embodiment, Bernoulli's equation is:

[0078]

[0079] Where P is the fluid pressure, ρ is the fluid density, v is the fluid velocity, g is the gravitational acceleration, h is the fluid height relative to the reference point, and a is a constant.

[0080] According to Bernoulli's equation, the wind speed and air pressure at different cross-sections in the duct can be calculated, taking into account the effect of changes in duct height on fluid pressure.

[0081] The areas in the air duct that may generate local resistance are mainly the bends and diameter changes of the air duct. These areas can cause abnormal changes in wind speed and air pressure, so the areas that generate local resistance and friction can be identified accordingly.

[0082] Then, the modified Bernoulli equation is used (this is usually achieved by adding an energy loss term such as Δh). Incorporating the energy loss term to account for the effects of friction and local drag on wind speed and pressure is beneficial for calculating the effects of local drag and friction on wind speed and pressure.

[0083] Adjusting the air duct can be done by changing its cross-sectional area and radius of curvature, which helps reduce local resistance and energy loss. By changing the cross-sectional area and radius of curvature of the air duct, the energy loss of hot air in the duct can be altered, thereby helping to maintain a uniform pressure and velocity distribution of the hot air in the duct by reducing energy loss.

[0084] In this embodiment, by optimizing the duct design, it is beneficial to achieve the optimal distribution of wind speed and air pressure in the hot air circulation system. Furthermore, by designing the duct based on the energy loss from local resistance and friction, it is beneficial to further improve the overall efficiency and performance of the system.

[0085] Understandably, heat sources and fans require regular inspection, cleaning, and maintenance to ensure their efficient operation and prevent system inefficiency and potential safety risks. Preferably, environmentally friendly heat sources, such as biomass fuels or solar energy, are used to reduce carbon emissions.

[0086] Furthermore, after drying, the lithium carbonate needs to be cooled to prevent excessive temperature from affecting subsequent processing, and large particulate impurities are removed by sieving to ensure that the quality of the material meets the requirements of the next step of pulverization.

[0087] Preferably, the temperature, humidity and material status during the drying process are monitored in real time by sensors, and samples are periodically taken from the drying process for quality analysis to ensure that the drying effect meets the predetermined standards. Based on the monitoring and sampling results, drying parameters, such as temperature and wind speed, are adjusted to optimize drying efficiency and product quality.

[0088] S5. The dried lithium carbonate precipitate is pulverized to obtain lithium carbonate powder.

[0089] Optionally, step S5 includes:

[0090] (51) Use airflow to crush the dried lithium carbonate precipitate.

[0091] (52) Adjust the flow rate and pressure of the airflow to adjust the crushing force and obtain lithium carbonate powder with a preset particle size.

[0092] In this embodiment, an air jet mill is used to pulverize the dried lithium carbonate precipitate. The air jet mill includes a nozzle and a pulverizing chamber; optimizing the design of the nozzle and pulverizing chamber helps to improve pulverizing efficiency.

[0093] Optionally, step (51) includes:

[0094] Multiple simulated grinding chambers are generated; the optimal grinding efficiency for each simulated grinding chamber is determined by adjusting the internal conditions of each simulated grinding chamber; the optimal grinding efficiency of each simulated grinding chamber is compared to determine the optimal simulated grinding chamber and serve as a design template for grinding chambers used to grind lithium carbonate precipitates.

[0095] Understandably, different grinding chambers have different airflow characteristics due to their varying geometries, which affects grinding efficiency. Furthermore, the simulated grinding chamber conditions include fluid velocity, pressure, density, and volumetric forces (such as gravity), as well as the amount of material to be ground; all of these conditions influence grinding efficiency. By adjusting these conditions and testing the grinding effect on the material within the chamber, the optimal chamber conditions and optimal grinding effect (i.e., optimal grinding efficiency) can be selected.

[0096] Furthermore, the simulated grinding chamber can be further optimized. For example, the geometry of the simulated grinding chamber can be changed to generate high-speed airflow, improve the interaction between the material and the airflow, and thus improve the grinding efficiency; the airflow path in the simulated grinding chamber can be optimized to reduce eddies and dead zones, ensure uniform distribution of fluid in the grinding chamber, and adjust the airflow speed and direction to ensure that the material can be fully subjected to impact and shear forces in the grinding chamber; and the airflow dynamics characteristics at the outlet can be designed to effectively and quickly transport the ground material out of the grinding chamber.

[0097] Optionally, step (52) further includes:

[0098] Obtain the geometric parameters of the simulated grinding chamber, the physical parameters of the dried lithium carbonate precipitate, and the airflow parameters; based on the geometric, physical, and airflow parameters, simulate the grinding motion of the dried lithium carbonate precipitate in the simulated grinding chamber to obtain simulation results; adjust the geometric or airflow parameters until the optimal simulation results are obtained; based on the optimal simulation results, adjust the airflow rate, air pressure, and the rate at which the dried lithium carbonate precipitate enters the grinding chamber to adjust the grinding intensity and obtain lithium carbonate powder of a preset particle size.

[0099] In this embodiment, the geometric parameters include the size and shape of the grinding chamber and the configuration of the airflow nozzles; the physical parameters include the density, particle size distribution, and hardness of the material to be ground; and the airflow parameters include the airflow velocity, air pressure, and density.

[0100] Understandably, to simulate the movement of dried lithium carbonate precipitate during the pulverization process in a simulated pulverizing chamber, it is necessary to use the momentum equation to determine the relationship between parameters such as airflow velocity, air pressure, and density, and how these parameters affect the pulverization process of the material.

[0101] The momentum equation is:

[0102]

[0103] Where ρ is the fluid density, u is the fluid vector, V is the control volume, S is the control surface, f is the volume force, and T is the stress tensor.

[0104] The momentum equation is used to predict the trajectory of the material in the grinding chamber, thereby simulating the motion of the grinding chamber and obtaining simulation results.

[0105] Specifically, the calculation steps involved in the simulation process include:

[0106] Calculate the minimum impact energy required to crush materials, using the formula... Where E is the minimum impact energy, m is the mass of the material to be crushed, and v is the minimum speed required for crushing.

[0107] Calculate the airflow velocity, where the airflow velocity is calculated according to p = mv, where p is momentum and m is the mass of the material to be crushed, and determine the airflow velocity v to transfer the required momentum to the material.

[0108] The airflow parameters are quantified, and the density and pressure of the gas are calculated according to the ideal gas law PV=nRT, where P is the pressure, V is the volume, n is the number of moles of gas, R is the ideal gas constant, and T is the temperature.

[0109] Optionally, during the simulation process, the output simulation results include airflow rate and air pressure. Based on the optimal simulation results, i.e. the optimal airflow rate and air pressure, the airflow rate and air pressure in the actual pulverizing chamber are adjusted to achieve the optimal pulverizing effect.

[0110] Furthermore, in order to improve the pulverization effect, the rate at which the material to be pulverized is fed into the pulverization chamber can be controlled based on the simulated movement of the material in the pulverization chamber.

[0111] Specifically, according to the equation Calculate the momentum change of the material to be pulverized under the action of airflow. Here, F is the net force acting on the material, ρ is the density of the material, and v is the velocity of the material. After determining the velocity of the material and the net force acting on it, its trajectory, velocity distribution, and impact zone within the pulverizing chamber can be simulated to analyze the pulverizing effect. Based on the pulverizing effect, the geometric parameters and airflow parameters of the pulverizing chamber can be adjusted until the optimal pulverizing effect is obtained.

[0112] Optionally, the method for preparing lithium carbonate based on lepidolite further includes:

[0113] Obtain the physical parameters of the dried lithium carbonate precipitate; based on the physical parameters, determine the energy required to pulverize each unit of lithium carbonate precipitate; under the condition of reaching this energy, adjust the operating parameters during the pulverization process of the lithium carbonate precipitate and determine the energy consumption value of the pulverization process until the optimal energy consumption value is obtained, wherein the operating parameters include at least the airflow speed, air pressure and ambient temperature.

[0114] In this embodiment, the physical parameters of the dried lithium carbonate precipitate include density, particle size, hardness, etc. When determining the energy required to crush each unit of lithium carbonate precipitate, it can be estimated by the kinetic energy of the airflow or the momentum change of the material. The momentum of the material can be calculated based on the physical parameters of the lithium carbonate precipitate and the momentum equation.

[0115] Adjusting the operating parameters during the pulverization of lithium carbonate precipitate refers to modifying airflow rate, air pressure, ambient temperature, or the geometry of the pulverization chamber. It's understood that the energy consumption during pulverization refers to the energy consumed in airflow generation, transmission, and exhaust gas treatment; these energy consumption values ​​can be quantified. When adjusting the operating parameters during the pulverization of lithium carbonate precipitate, by comparing the energy consumption values ​​under different operating parameters while maintaining the energy required to pulverize each unit of lithium carbonate precipitate, the minimum energy consumption value under the optimal operating parameters can be determined.

[0116] Optionally, the exhaust gas emitted during the crushing process can be purified to ensure compliance with environmental standards.

[0117] Optionally, the method for preparing lithium carbonate based on lepidolite further includes:

[0118] After being pulverized to obtain lithium carbonate powder, the material is graded to ensure that the particle size is uniform and meets the standard requirements, and then the lithium carbonate powder is packaged.

[0119] This application provides a method for preparing lithium carbonate based on lepidolite. First, lepidolite is obtained. Second, the lepidolite is calcined. Next, the calcined lepidolite is dissolved in a solvent, and lithium carbonate precipitate is extracted from the resulting mixture. Then, the lithium carbonate precipitate is dried using hot air circulating through a duct, with the temperature and flow rate of the hot air controlled according to a preset threshold. Finally, the dried lithium carbonate precipitate is pulverized to obtain lithium carbonate powder. In the drying step, this application uses hot air circulating in a duct to continuously dry the lithium carbonate precipitate, reducing heat loss and saving energy consumed in heating the air. Simultaneously, controlling the temperature and flow rate of the hot air according to a preset threshold satisfies the drying requirements while avoiding energy waste caused by excessively high temperatures and flow rates, thus reducing energy consumption in the lithium carbonate preparation process.

[0120] Please see Figure 2 This application also provides a lithium carbonate preparation system based on lepidolite, comprising:

[0121] Acquisition unit 201 is used to acquire lepidolite;

[0122] The calcination unit 202 is used to calcine lepidolite;

[0123] The reaction unit 203 is used to dissolve the calcined lepidolite using a solvent and extract lithium carbonate precipitate from the resulting mixture.

[0124] The drying unit 204 is used to dry lithium carbonate precipitate by circulating hot air through the air duct, and to adjust the temperature and flow rate of the hot air according to a preset threshold.

[0125] The pulverizing unit 205 is used to pulverize the dried lithium carbonate precipitate to obtain lithium carbonate powder.

[0126] Optionally, the acquisition unit 201 includes:

[0127] The cutting module is used to crush the lepidolite after it has been obtained to obtain multiple lepidolite fragments.

[0128] The screening module is used to screen multiple lepidolite fragments based on preset particle size values ​​to obtain screened lepidolite.

[0129] Optionally, the drying unit 204 is also used for:

[0130] When using hot air to dry lithium carbonate precipitate, the degree of dryness of the lithium carbonate precipitate is determined based on its moisture content. When the degree of dryness of the lithium carbonate precipitate reaches the preset standard value, the temperature and flow rate of the hot air are adjusted, and the heat generated by the hot air during the adjustment process is obtained by using a heat exchanger to recover the heat of the hot air.

[0131] Optionally, the drying unit 204 is also used for:

[0132] Based on preset standard values, the target wind speed and target air pressure of the hot air are determined; the current wind speed and current air pressure of the hot air are obtained through sensor components; the current wind speed is adjusted to the target wind speed by adjusting the speed of the fan in the air duct, and the current air pressure is adjusted to the target air pressure by adjusting the dampers and valves in the air duct.

[0133] Optionally, the drying unit 204 is also used for:

[0134] Using Bernoulli's equation, the relationship between wind speed, air pressure, and altitude at each cross-section of the duct is determined. Based on this relationship, the regions in the duct that generate local resistance and friction are identified, and the energy loss value of hot air passing through these regions is determined. Based on the energy loss value, the duct is adjusted.

[0135] Optionally, the crushing unit 205 is also used for:

[0136] The dried lithium carbonate precipitate is pulverized using airflow; the flow rate and pressure of the airflow are adjusted to regulate the pulverizing force and obtain lithium carbonate powder of a preset particle size.

[0137] Optionally, the crushing unit 205 also includes a calculation module, which is used for:

[0138] Multiple simulated grinding chambers are generated; the optimal grinding efficiency for each simulated grinding chamber is determined by adjusting the internal conditions of each simulated grinding chamber; the optimal grinding efficiency of each simulated grinding chamber is compared to determine the optimal simulated grinding chamber and serve as a design template for grinding chambers used to grind lithium carbonate precipitates.

[0139] Optionally, the computing module is also used for:

[0140] Obtain the geometric parameters of the simulated grinding chamber, the physical parameters of the dried lithium carbonate precipitate, and the airflow parameters; based on the geometric, physical, and airflow parameters, simulate the grinding motion of the dried lithium carbonate precipitate in the simulated grinding chamber to obtain simulation results; adjust the geometric or airflow parameters until the optimal simulation results are obtained; based on the optimal simulation results, adjust the airflow rate, air pressure, and the rate at which the dried lithium carbonate precipitate enters the grinding chamber to adjust the grinding intensity and obtain lithium carbonate powder of a preset particle size.

[0141] Optionally, the lithium carbonate preparation system based on lepidolite further includes a monitoring unit, which is used for:

[0142] Obtain the physical parameters of the dried lithium carbonate precipitate; based on the physical parameters, determine the energy required to pulverize each unit of lithium carbonate precipitate; adjust the operating parameters during the pulverization process of the lithium carbonate precipitate until the energy reaches the target energy value, wherein the operating parameters include at least the airflow speed, air pressure and ambient temperature.

[0143] This application provides a lithium carbonate preparation system based on lepidolite. First, an acquisition unit 201 acquires lepidolite. Second, a calcination unit 202 calcines the lepidolite. Next, a reaction unit 203 dissolves the calcined lepidolite using a solvent and extracts lithium carbonate precipitate from the resulting mixture. Then, a drying unit 204 circulates hot air through a duct to dry the lithium carbonate precipitate, controlling the temperature and flow rate of the hot air according to a preset threshold. Finally, a pulverizing unit 205 pulverizes the dried lithium carbonate precipitate to obtain lithium carbonate powder. In the drying process, this application uses hot air circulating in a duct to continuously dry the lithium carbonate precipitate, reducing heat loss and saving energy consumed in heating the air. Simultaneously, controlling the temperature and flow rate of the hot air according to a preset threshold satisfies the drying requirements while avoiding energy waste caused by excessively high temperatures and flow rates, thus reducing energy consumption during lithium carbonate preparation.

[0144] This application also provides tests on the physical properties of lithium carbonate powder prepared by the above-described lithium carbonate preparation method and system based on lepidolite, and the test results are as follows:

[0145] Particle size distribution (D50, μm): 5.5 μm ≤ 7 μm

[0146] Specific surface area (m²) 2 / g):2.8m 2 / g, conforming to 2m 2 / g to 3m 2 Within the range of / g

[0147] Moisture content (%): 0.05% ≤ 0.1%

[0148] Impurity content (%): 0.02% ≤ 0.05%

[0149] This application also uses the lithium carbonate powder obtained from the above-mentioned lithium mica-based lithium carbonate preparation method and system to prepare an optimized lithium battery, and tests the performance of the optimized lithium battery. The test results are compared with the performance of existing lithium batteries.

[0150] The optimized lithium battery has a charging capacity of 210 mAh / g, while the existing lithium battery has a charging capacity of 195 mAh / g.

[0151] The optimized lithium battery has a discharge capacity of 205 mAh / g, while the existing lithium battery has a charge capacity of 190 mAh / g.

[0152] The optimized lithium battery has a cycle stability (capacity retention after 500 cycles) of 92%, while the existing lithium battery has a charge capacity of 85%.

[0153] The optimized lithium battery has an internal resistance of 40 Ω, while the existing lithium battery has an internal resistance of 50 Ω, measured in mΩ.

[0154] The lithium carbonate preparation method of this application reduces energy consumption and raw material consumption, lowers the production cost from RMB 100 per kilogram to RMB 85, ​​and reduces the exhaust gas emission from 150 milligrams per cubic meter to 50 milligrams.

[0155] Although this application has been shown and described with respect to one or more implementations, equivalent variations and modifications will occur to those skilled in the art based on a reading and understanding of this specification and drawings. This application includes all such modifications and variations and is limited only by the scope of the appended claims.

[0156] That is, the above description is only an embodiment of this application and does not limit the patent scope of this application. Any equivalent structural or procedural changes made using the content of this application’s specification and drawings, such as the combination of technical features between embodiments, or direct or indirect application in other related technical fields, are similarly included within the patent protection scope of this application.

[0157] Any process or method description in the flowchart or otherwise herein can be understood as representing a module, segment, or portion of code comprising one or more executable instructions for implementing a particular logical function or process, and the scope of the preferred embodiments of this application includes additional implementations in which functions may be performed not in the order shown or discussed, including substantially simultaneously or in reverse order depending on the function involved, as should be understood by those skilled in the art to which embodiments of this application pertain.

[0158] Furthermore, for structural elements with the same or similar characteristics, this application may use the same or different reference numerals for identification. In addition, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, features defined with "first" and "second" may explicitly or implicitly include one or more features. In the description of this application, "a plurality of" means two or more, unless otherwise explicitly specified.

[0159] In this application, the above description has been provided to enable any person skilled in the art to implement and use the application. Various details have been set forth in the above description for purposes of explanation. It should be understood that those skilled in the art will recognize that the application can be implemented without using these specific details. In other embodiments, well-known structures and processes will not be described in detail to avoid obscuring the description of the application with unnecessary detail. Therefore, this application is not intended to be limited to the embodiments shown, but is consistent with the broadest scope of the principles and features disclosed herein.

Claims

1. A method for preparing lithium carbonate based on lepidolite, characterized in that, include: Obtaining lepidolite; The lepidolite is calcined; The calcined lepidolite was dissolved using a solvent, and lithium carbonate precipitate was extracted from the resulting mixture. The lithium carbonate precipitate is dried by circulating hot air through an air duct, and the temperature and flow rate of the hot air are adjusted according to a preset threshold. The dried lithium carbonate precipitate is pulverized to obtain lithium carbonate powder; The step of pulverizing the dried lithium carbonate precipitate to obtain lithium carbonate powder includes: The dried lithium carbonate precipitate is pulverized using an airflow. Adjust the flow rate and pressure of the airflow to regulate the crushing force and obtain lithium carbonate powder of a preset particle size; The step of pulverizing the dried lithium carbonate precipitate to obtain lithium carbonate powder further includes: Multiple simulated grinding chambers are generated; The optimal grinding efficiency for each simulated grinding chamber is determined by adjusting the indoor conditions of each simulated grinding chamber. The optimal pulverization efficiency of each of the simulated pulverization chambers is compared to determine the optimal simulated pulverization chamber, which serves as a design template for the pulverization chamber used to pulverize the lithium carbonate precipitate. The method of adjusting the flow rate and pressure of the airflow to regulate the pulverizing force and obtain lithium carbonate powder of a preset particle size further includes: Obtain the geometric parameters of the simulated pulverizing chamber, the physical parameters of the dried lithium carbonate precipitate, and the airflow parameters; Based on the geometric parameters, physical parameters, and airflow parameters, the motion of the dried lithium carbonate precipitate during pulverization in the simulated pulverization chamber is simulated to obtain simulation results. Adjust the geometric parameters or the airflow parameters until the optimal simulation result is obtained; Based on the optimal simulation results, the flow rate, air pressure, and rate at which the dried lithium carbonate precipitate enters the pulverizing chamber are adjusted to regulate the pulverizing force and obtain lithium carbonate powder with a preset particle size.

2. The method for preparing lithium carbonate based on lepidolite according to claim 1, characterized in that, The acquisition of lithium mica includes: After obtaining the lepidolite, the lepidolite is crushed to obtain multiple lepidolite fragments; Based on a preset particle size value, the multiple lithium mica fragments are screened to obtain screened lithium mica.

3. The method for preparing lithium carbonate based on lepidolite according to claim 1, characterized in that, The process of drying the lithium carbonate precipitate by circulating hot air through an air duct, and adjusting the temperature and flow rate of the hot air according to a preset threshold, includes: When the lithium carbonate precipitate is dried using the hot air, the degree of dryness of the lithium carbonate precipitate is determined based on its moisture content. When the degree of dryness of the lithium carbonate precipitate reaches the preset standard value, the temperature and flow rate of the hot air are adjusted, and the heat of the hot air during the adjustment process is obtained by using a heat exchanger to recover the heat of the hot air.

4. The method for preparing lithium carbonate based on lepidolite according to claim 3, characterized in that, The adjustment of the hot air flow rate includes: Based on the preset standard values, the target wind speed and target air pressure of the hot air are determined; The current wind speed and current air pressure of the hot air are obtained through sensor components; The current wind speed is adjusted to the target wind speed by adjusting the rotational speed of the fan in the air duct, and the current air pressure is adjusted to the target air pressure by adjusting the dampers and valves in the air duct.

5. The method for preparing lithium carbonate based on lepidolite according to claim 4, characterized in that, The method of drying the lithium carbonate precipitate by circulating hot air through an air duct, and adjusting the temperature and flow rate of the hot air according to a preset threshold, further includes: Using Bernoulli's equation, the relationship between wind speed, air pressure, and height at each cross-section of the duct is determined; Based on the relationship between wind speed, air pressure and height at each cross-section of the duct, the regions in the duct that generate local resistance and friction are identified, and the energy loss value of the hot air when passing through the regions is determined. The air duct is adjusted based on the energy loss value.

6. The method for preparing lithium carbonate based on lepidolite according to claim 1, characterized in that, Also includes: Obtain the physical parameters of the dried lithium carbonate precipitate; Based on the physical parameters, determine the energy required to pulverize each unit of the lithium carbonate precipitate; Under the condition of achieving the energy, the operating parameters of the lithium carbonate precipitate are adjusted and the energy consumption value of the pulverization process is determined until the optimal energy consumption value is obtained. The operating parameters include at least the airflow speed, air pressure and ambient temperature.

7. A lithium carbonate preparation system based on lepidolite, characterized in that, include: Acquisition unit, used to acquire lepidolite; A calcination unit is used to calcine the lepidolite; The reaction unit is used to dissolve calcined lepidolite using a solvent and extract lithium carbonate precipitate from the resulting mixture. The drying unit is used to dry the lithium carbonate precipitate by circulating hot air through the air duct, and to adjust the temperature and flow rate of the hot air according to a preset threshold. A pulverizing unit is used to pulverize the dried lithium carbonate precipitate to obtain lithium carbonate powder; The crushing unit is also used for: The dried lithium carbonate precipitate is pulverized using airflow; the flow rate and pressure of the airflow are adjusted to regulate the pulverization force and obtain lithium carbonate powder of a preset particle size. The pulverizing unit further includes a calculation module, which is used to: generate multiple simulated pulverizing chambers; determine the optimal pulverizing efficiency for each simulated pulverizing chamber by adjusting the indoor conditions of each simulated pulverizing chamber; compare the optimal pulverizing efficiency of each simulated pulverizing chamber to determine the optimal simulated pulverizing chamber and use it as a design template for the pulverizing chamber used to pulverize the lithium carbonate precipitate. The calculation module is further configured to: acquire the geometric parameters of the simulated grinding chamber, the physical parameters of the dried lithium carbonate precipitate, and the airflow parameters; simulate the movement of the dried lithium carbonate precipitate during grinding within the simulated grinding chamber based on the geometric parameters, the physical parameters, and the airflow parameters to obtain simulation results; adjust the geometric parameters or the airflow parameters until the optimal simulation results are obtained; and adjust the flow rate, air pressure, and the rate at which the dried lithium carbonate precipitate enters the grinding chamber based on the optimal simulation results to adjust the grinding intensity and obtain lithium carbonate powder of a preset particle size.

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