A method for strengthening the phase reconstruction of spodumene ore and its reaction device

Abstract

The present invention discloses a method for strengthening the phase reconstruction of spodumene ore and its reaction device, comprising the following steps: placing spodumene ore in a reaction kettle, adding an alkali solution, an auxiliary agent and grinding balls, and sealing the reaction kettle; the sealed reaction kettle lies on its side and rotates along its own axis, and the materials in the reaction kettle undergo a hydrothermal alkali leaching reaction, and the spodumene ore phase is reconstructed; after the reaction is completed, the reaction materials are collected, and solid-liquid separation is carried out to obtain alkali leaching residues and alkali leaching solutions. The alkali leaching residues are dried, and the alkali leaching residues are mixed with an extractant to carry out an alkali leaching residue extraction reaction, and a lithium-rich solution is obtained after the reaction. On the basis of grinding and leaching simultaneously during the hydrothermal alkali leaching of spodumene, the present invention adds an auxiliary agent, so that the mineral is not only fully mechanically activated, but also the activity of the reactants is increased under low-temperature conditions, further strengthening the spodumene ore phase reconstruction process, improving the lithium extraction efficiency, and realizing a low-temperature short-process and high-efficiency α-spodumene lithium extraction technology.

Description

Technical Field

[0001] The present invention belongs to the technical field of mineral processing and equipment. Specifically, it relates to a method for enhancing the phase reconstruction of spodumene in an alkaline hydrothermal system and its multi-position horizontal rotary reaction device. Background Art

[0002] Lithium, as an essential component material for new energy power batteries, with the rapid development of the new energy industry, the demand for lithium batteries is increasing rapidly. Spodumene ore is one of the main lithium ore resources for commercial mining, having advantages such as high grade, few impurities, and rich reserves. The main methods for extracting lithium from spodumene include the sulfuric acid method (such as patents CN103950956A, CN104071811A, CN114436300A, etc.), the limestone roasting method, and the autoclave leaching method (such as patents CN101948124A, CN103183366A, CN107473244A, etc.). The sulfuric acid method that transforms α-spodumene through high-temperature roasting at about 1000 °C to obtain β-type spodumene with more active chemical properties and then further extracts lithium is still the current mainstream production process. However, such processes generally have problems such as high energy consumption, long process flow, and acidic gas emissions.

[0003] CN115477289A discloses a method for extracting lithium by phase reconstruction of α-spodumene ore. This method enables the phase reconstruction of α-spodumene under low-temperature conditions through a hydrothermal alkali leaching reaction to obtain a new lithium-containing solid phase that is easily soluble in acid, and then obtains a lithium-rich solution through an alkali leaching residue leaching reaction. It does not require high-temperature calcination and activation of spodumene, and is a green and clean method for extracting lithium from spodumene, with great application potential. However, in the existing methods for extracting lithium by phase reconstruction of alkali-leached α-spodumene ore, the reaction pressure is generally high, the requirements for reaction equipment and conditions are relatively strict, and the lithium extraction efficiency still needs to be further improved. Summary of the Invention

[0004] The purpose of the present invention is to overcome the deficiencies in the prior art and provide a method for enhancing the phase reconstruction of spodumene and its reaction device. Based on the rotary reaction device, the reaction kettle rotates around its own internal axis during operation. Using spodumene as the raw material, through steps of adding alkali solution, grinding balls, additives for mixing, spodumene phase reconstruction, solid-liquid separation of the slurry, and acid leaching of the spodumene ore slag to obtain a lithium-rich solution, it realizes the low-temperature alkali leaching reaction of spodumene and full mechanical activation, enhances the phase reconstruction process of spodumene, and obtains a low-temperature and high-efficiency lithium extraction process for spodumene.

[0005] To achieve the above purpose, the present invention adopts the following technical solutions:

[0006] A method for enhancing the phase reconstruction of spodumene, the method comprising the following steps:

[0007] (1) Place the spodumene ore in a reaction kettle, add lye, additives and grinding balls, and seal the reaction kettle.

[0008] (2) After sealing, the reaction kettle lies on its side and rotates along its own axis, and the hydrothermal alkali leaching reaction occurs in the reaction kettle, and the spodumene ore phase is reconstructed.

[0009] (3) After the reaction is completed, collect the reaction materials and perform solid-liquid separation to obtain alkali leaching residues and alkali leaching solutions.

[0010] (4) Dry the alkali leaching residues, mix the alkali leaching residues with the leaching agent to carry out the alkali leaching residue leaching reaction, and obtain a lithium-rich solution after the reaction.

[0011] The present invention is further configured such that the particle size of the spodumene ore is 50-200 mesh.

[0012] The present invention is further configured such that the lye is sodium hydroxide solution or potassium hydroxide solution, and the ratio of spodumene ore to lye in step (1) is by mass:

[0013] Spodumene ore: 20-40 parts;

[0014] Sodium hydroxide: 30-60 parts or potassium hydroxide: 40-90 parts;

[0015] Water: 60-180 parts.

[0016] Furthermore, the mass ratio of the additive to the spodumene ore is 5%-25%; the mass ratio of the grinding balls to the spodumene ore is (5-20):1.

[0017] Furthermore, the total volume of the reaction materials in the reaction kettle does not exceed 80% of the inner volume of the reaction kettle.

[0018] The present invention is further configured such that the additive in step (1) is potassium sulfate, potassium carbonate, potassium chloride, sodium sulfate or sodium carbonate.

[0019] The present invention is further configured such that the specific combination of the lye and the additive in step (1) is:

[0020] When the lye is sodium hydroxide solution, the additive is selected from potassium sulfate, potassium carbonate, potassium chloride or sodium carbonate;

[0021] When the lye is potassium hydroxide solution, the additive is selected from sodium sulfate or sodium carbonate.

[0022] The present invention is further configured such that the material of the grinding balls in step (1) is 316L stainless steel material, and the grinding balls include three different specifications of large grinding balls, medium grinding balls and small grinding balls. The sizes of different specifications of grinding balls are preferably 10mm, 8mm and 5mm respectively. Specifically, the ratio of different specifications of grinding balls in the grinding balls is by mass:

[0023] Large grinding balls: 50% - 70%;

[0024] Medium grinding balls: 15% - 28%;

[0025] Small grinding balls: 12% - 22%.

[0026] The present invention is further configured such that the temperature of the hydrothermal alkali leaching reaction in step (2) is set to 150 - 200 °C, preferably 180 - 200 °C. In the hydrothermal alkali leaching reaction system of the present invention, the pressure inside the reaction kettle is closely related to the temperature setting. When the temperature is set to 250 °C, the pressure inside the reaction kettle is about 2.6 MPa, while when the temperature drops to 180 - 200 °C, the pressure inside the reaction kettle drops to about 0.4 - 0.8 MPa, and the pressure inside the kettle drops significantly.

[0027] The present invention is further configured such that the rotation speed of the reaction kettle in the hydrothermal alkali leaching reaction in step (2) is 50 - 600 r / min, and the reaction time is 8 - 24 h.

[0028] The present invention is further configured such that the solid-liquid separation method in step (3) adopts centrifugation, filtration or hydrocyclone separation.

[0029] The present invention is further configured such that after the solid-liquid separation of the reaction slurry in step (3), an alkali leaching residue and an alkali leaching solution are obtained. The alkali leaching solution is recycled to step (1) to repeat the hydrothermal alkali leaching reaction; the alkali leaching residue is dried, the drying temperature is 110 °C, and the drying time is 0 - 24 h. Further, in the hydrothermal alkali leaching reaction, a new lithium-containing solid phase - lithium metasilicate is generated, and lithium metasilicate exists in the alkali leaching residue.

[0030] The present invention is further configured such that the leaching agent in step (4) is sulfuric acid or hydrochloric acid, and the dried alkali leaching residue is used for acid leaching. Further, the reaction conditions for the acid leaching are set as follows: the reaction time is 5 - 120 min, the reaction temperature is 25 - 30 °C, the leaching agent used for the acid leaching is 0.5 - 1 mol / L sulfuric acid or 1 - 2 mol / L hydrochloric acid, and the liquid-solid ratio is (2 - 10):1, preferably (4 - 6):1.

[0031] Another aspect of the present invention lies in providing a multi-position horizontal rotary reaction device for the method of strengthening the phase reconstruction of spodumene ore. The reaction device includes a hot air box, a power rotation system, a number of reaction kettles and a control cabinet, wherein:

[0032] The power rotation system includes a motor, a transmission structure and a rotating shaft structure, and the rotating shaft structure is arranged in the hot air box; grinding balls are placed in the reactor, lying on their sides on the rotating shaft structure, and the rotating shaft structure drives the reactor to rotate around the central axis of the reactor body by friction, and the material in the reactor undergoes grinding and soaking reaction; the control cabinet is communicatively connected to the hot air box and the power rotation system, and is used to control the temperature in the hot air box and the operating status of the power rotation system.

[0033] The present invention is further configured such that the hot air box is a constant temperature hot air box which can adjust and maintain a constant temperature within the range of room temperature to 300°C; a transparent box cover is provided on the top or side of the hot air box to facilitate operators to observe the operation of the equipment and place and remove the reactor.

[0034] The present invention is further configured as follows: the control cabinet includes a control cabinet frame and a controller arranged in the control cabinet frame, and a control panel is provided on the surface of the controller; a temperature sensor is provided in the hot air box, and a speed sensor is provided on the rotating shaft structure, and the temperature sensor and the speed sensor are both communicatively connected to the controller, and parameters such as the temperature in the hot air box, the rotating shaft speed, and the reactor speed are displayed in real time on the control panel; the controller is communicatively connected to the hot air box and the motor, and controls the heating program of the hot air box and the operating status of the motor according to the parameter signal received by the sensor and the parameters set on the control panel.

[0035] The present invention is further configured such that the hot air box is placed above or inside the control cabinet frame, the motor is placed inside the control cabinet frame, and four universal wheels are installed at the bottom of the control cabinet frame to facilitate moving the reaction device. At the same time, the universal wheels can adjust the height to maintain the level of the rotating shaft structure.

[0036] The present invention is further configured such that the rotating shaft structure includes a plurality of rotating shafts arranged horizontally and in parallel, including a driving shaft and a plurality of driven shafts, bearings are provided at both ends of the rotating shafts, and the bearings are fixedly connected to the outer side of the hot air box.

[0037] The present invention is further configured such that the transmission structure includes a plurality of transmission belts whose number is the same as the rotating shafts, which transmission connect the motor and the rotating shafts, including an active transmission belt and a plurality of driven transmission belts, wherein the active transmission belt transmission connects the motor and the active shaft; the driven transmission belt transmission connects the active shaft and a plurality of driven shafts one by one; a transmission roller is provided between the transmission belt and the rotating shaft, so that the motor can drive the rotating shaft to rotate through the transmission structure, and the rotation speed of the rotating shaft can reach up to 2000r / min.

[0038] The present invention is further configured such that the reaction kettle is placed horizontally above two adjacent rotating shafts, and the reaction kettle and the rotating shaft structure are independent of each other.

[0039] The present invention is further configured such that a plurality of position-adjustable limiting rings are provided on the rotating shaft, and the position of the limiting ring is adjusted to adapt to reaction kettles of different sizes, so as to prevent lateral deviation or mutual collision of the reaction kettle during rotation due to the height not reaching the horizontal, and play a blocking role.

[0040] The present invention is further configured such that the reaction kettle includes a reaction kettle outer shell and a reaction kettle inner lining. The reaction kettle outer shell includes an outer shell cylinder body and an outer shell cover. The reaction kettle inner lining includes an inner lining cylinder body and an inner lining cover. The reaction kettle inner lining is placed inside the reaction kettle outer shell. The reaction kettle outer shell is sealed by screwing the internal thread of the outer shell cylinder body and the external thread of the outer shell cover, so that the reaction kettle inner lining has good sealing performance.

[0041] The present invention is further configured such that the material of the reaction kettle inner lining is p-phenylphenol.

[0042] The present invention is further configured such that the outer diameter of the outer shell cover is less than or equal to the outer diameter of the outer shell cylinder body, and due to the uniform outer diameter of the outer shell cylinder body, after the reaction kettle is placed horizontally on the rotating shaft structure, it rotates around its own central axis inside.

[0043] The present invention is further configured such that a clamp is installed on the control cabinet frame for tightening the reaction kettle outer shell.

[0044] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0045] (1) In the method for strengthening the mineral phase reconstruction of spodumene in the present invention, spodumene undergoes mineral phase reconstruction under low-temperature alkaline hydrothermal conditions, and further low-temperature acid leaching of the slag gives a lithium-rich solution. During the alkali leaching reaction process, mechanical activation by grinding makes the mineral break or deform to generate lattice defects, activating the chemical activity of the spodumene ore and improving the lithium extraction efficiency.

[0046] (2) Based on the mechanical activation method of grinding while leaching, the present invention adds additives under low-temperature conditions, so that the mineral is not only fully mechanically activated, but also the mineral phase reconstruction process of the reactants is strengthened under low-temperature conditions, further improving the lithium extraction rate, reducing the reaction temperature and pressure, and providing a low-temperature short-process and high-efficiency α-spodumene lithium extraction technology. Under the conditions of 180-200 °C, a lithium extraction rate of more than 85% can be achieved by the method of grinding while leaching with additives.

[0047] (3) The multi-bit horizontal rotary reaction device for strengthening the phase reconstruction of spodumene ore is applicable to the hydrothermal grinding and leaching of spodumene minerals. During operation, the reaction kettle rotates horizontally inside the hot air box. By adding grinding ball media, both mechanical activation of mineral raw materials and hydrothermal reaction can be achieved. Moreover, since the reaction kettle rotates around its own axis, the rotation radius of the grinding balls rotating inside the reaction kettle is small. At a certain rotational speed, the centripetal force of the grinding balls is small, and a better mechanical activation effect can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 It is a schematic structural diagram of the multi-bit horizontal rotary reaction device described in the present invention;

[0049] Figure 2 It is a top view of the reaction kettle and the power rotation system in a preferred embodiment of the present invention;

[0050] Figure 3 It is an exploded view of the structure of the reaction kettle of the present invention;

[0051] Figure 4 It is a graph of the lithium extraction rate obtained in Example 1;

[0052] Figure 5 It is a graph of the lithium extraction rate obtained in Example 2;

[0053] Figure 6 It is a graph of the lithium extraction rate obtained in Example 3;

[0054] Figure 7 It is a graph of the lithium extraction rate obtained in Example 4;

[0055] Figure 8 It is a graph of the lithium extraction rate obtained in Example 5;

[0056] Figure 9 It is a graph of the lithium extraction rate obtained in Example 6;

[0057] Figure 10 It is an XRD pattern of the alkali leaching slag obtained from the reaction kettle under different batching in Example 1. Among them, the X-ray diffractometer scans the entire area at an angle of 2θ;

[0058] Figure 11 It is an SEM image of the alkali leaching slag obtained under different leaching methods in Example 5;

[0059] The attached reference numerals are: reactor 1, limit ring 2, rotating shaft structure 3, transmission structure 4, motor 5, universal wheel 6, control panel 7, control cabinet 8, main drive belt 9, first drive belt 10, second drive belt 11, main shaft 12, first driven shaft 13, second driven shaft 14, hot air box bracket 15, bench vice 16, hot air box 17, drive roller 18, bearing 19, box cover 20, control cabinet frame 21, outer shell cylinder 22, outer shell cover 23, inner lining cylinder 24, inner lining cover 25. Detailed implementation manners

[0060] The technical solutions of the present invention will be clearly and completely described below with specific embodiments. It should be understood that the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without making creative efforts shall fall within the scope of the present invention.

[0061] According to Figure 1 As shown, a multi-position horizontal rotary reaction device provided by the present invention includes a hot air box 17, a control cabinet 8, a power rotation system, and a plurality of reactors 1. The control cabinet 8 is communicably connected to the hot air box 17 and the power rotation system for controlling the temperature in the hot air box 17 and the operating state of the power rotation system. The power rotation system includes a motor 5, a transmission structure 4, and a rotating shaft structure 3. The rotating shaft structure 3 is disposed in the hot air box 17, and the reactor 1 is placed horizontally on the rotating shaft structure 3. The rotating shaft structure 3 drives the reactor 1 to rotate around the inner axis of the reactor body.

[0062] The hot air box 17 is a constant temperature hot air box, and the temperature can be adjusted in the range from room temperature to 300 °C. A transparent box cover 20 is provided above or on the side of the hot air box 17, which is convenient for operators to observe the operation of the equipment and place and take out the reactor 1.

[0063] The rotating shaft structure 3 includes a plurality of horizontally and parallelly arranged rotating shafts, including a main shaft and a plurality of driven shafts. As Figure 2 shown in the preferred embodiment, the rotating shaft structure 3 includes three rotating shafts, namely the main shaft 12, the first driven shaft 13, and the second driven shaft 14. Bearings 19 are provided at both ends of the rotating shaft, and the bearings 19 are fixedly connected to the outside of the hot air box 17.

[0064] The transmission structure 4 includes a number of drive belts that are the same in number as the rotation shafts, drivingly connecting the motor 5 and the rotation shafts. Among them, there is an active drive belt and a number of driven drive belts. The active drive belt is wound around the output rotating shaft of the motor 5 and the outside of the active shaft, connecting the motor 5 and the active shaft; the driven drive belts are respectively wound around the outside of the active shaft and the adjacent driven shaft, and the outside of two other adjacent driven shafts, drivingly connecting the active shaft and a number of driven shafts one by one. Between the drive belt and the rotation shaft, that is, on the outside of the rotation shaft and inside the drive belt, there are drive rollers 18, so that the motor 5 can drive the rotation shaft to rotate through the transmission structure. The maximum rotation speed of the rotation shaft can reach 2000 r / min. As Figure 2 In the preferred embodiment shown, the transmission structure 4 includes three drive belts, namely an active drive belt 9, a first drive belt 10, and a second drive belt 11. One end of the active shaft 12 is provided with two of the drive rollers 18, one end of the first driven shaft 13 is provided with two of the drive rollers 18, and one end of the second driven shaft 14 is provided with one of the drive rollers 18. And the above five drive rollers 18 are all arranged on the same side of the above three rotation shafts.

[0065] The reaction kettle 1 lies horizontally above the space between two adjacent rotation shafts, and the reaction kettle 1 is independent of the rotation shaft structure 3. Further, a number of position-adjustable limit rings 2 are provided on the rotation shaft, and by adjusting the positions of the limit rings 2, reaction kettles 1 of different sizes can be accommodated, playing a role in blocking.

[0066] The control cabinet 8 includes a control cabinet frame 21 and a controller arranged inside the control cabinet frame 21. A control panel 7 is provided on the surface of the controller. A temperature sensor is provided inside the hot air box 17, and a rotation speed sensor (not shown in the figure) is provided on the rotation shaft structure 3, respectively measuring the temperature inside the hot air box 17 and the rotation speed of the rotation shaft in real time. The rotation speed of the reaction kettle 1 can be calculated through the rotation speed of the rotation shaft, the circumference of the rotation shaft, and the ratio of the circumference of the reaction kettle. The temperature sensor and the rotation speed sensor are both communicably connected to the controller, and parameters such as the temperature inside the hot air box, the rotation speed of the rotation shaft, and the rotation speed of the reaction kettle are displayed on the control panel 7 in real time; the controller is communicably connected to the hot air box 17 and the motor 5, and according to the temperature inside the hot air box, the rotation speed of the rotation shaft, or the rotation speed of the reaction kettle set by the operator on the control panel 7, controls the heating program of the hot air box 17 and the operating state of the motor 5 to achieve the target parameters required for the reaction.

[0067] Further, as Figure 3As shown, the reactor 1 includes a reactor shell and a reactor liner, the reactor shell includes a shell cylinder 22 and a shell cover 23, the reactor liner includes a liner cylinder 24 and a liner cover 25, the reactor liner is placed in the reactor shell, the reactor shell is sealed by tightening the internal thread of the shell cylinder 22 and the external thread of the shell cover 23, so that the reactor liner has good sealing. The outer diameter of the shell cover 23 is less than or equal to the outer diameter of the shell cylinder 22. Since the shell cylinder 22 has a uniform outer diameter, the reactor 1 can stably rotate around its own central axis after being placed on its side on the rotating shaft structure 3.

[0068] Furthermore, a clamp 16 is installed on the control cabinet frame 21 for tightening the reactor shell.

[0069] The method for strengthening the spodumene mineral phase reconstruction using the above-mentioned multi-position horizontal rotary reaction device specifically includes the following steps:

[0070] (1) Weigh a certain amount of spodumene ore powder, alkali solution, additives and grinding balls and mix them in the inner lining cylinder 24 of the reactor.

[0071] (2) Add the lining cover 25 to the reactor liner cylinder 24 and place it into the reactor shell cylinder 22, and tighten the reactor shell cover 23 to seal the reactor liner.

[0072] (3) The tightened reactor 1 is placed sideways on the rotating shaft structure 3 .

[0073] (4) operating the control panel 7, adjusting the parameters of the horizontal rotary reaction device, specifying the reaction conditions, starting the reactor, and performing the spodumene mineral phase reconstruction reaction.

[0074] (5) After the reaction is completed, the reaction materials are collected, and solid-liquid separation, drying, and acid leaching are performed to obtain a lithium-rich solution.

[0075] In order to verify the performance and effect of the multi-position horizontal rotary reaction device and the enhanced spodumene mineral phase reconstruction provided by the present invention, the following examples provide different reaction ratios and reaction conditions for carrying out spodumene mineral phase reconstruction reaction in the multi-position horizontal rotary reaction device provided by the present invention, and the prepared spodumene slag samples are characterized by XRD and SEM, and the lithium extraction rate and mineral phase reconstruction rate obtained after acid leaching of the spodumene slag are calculated.

[0076] Example 1

[0077] In the first step, 20 g of spodumene powder (150 mesh), 30 g of sodium hydroxide and 90 g of water were added to the inner lining cylinder of a reactor with a volume of 250 mL and mixed thoroughly.

[0078] Step 2: Repeat the operation in Step 1 four times to obtain five reactors 1a, 1b, 1c, 1d, and 1e with the same ratio of ore raw materials to lye.

[0079] Step 3: Add 2.5 g of sodium carbonate, 2.5 g of potassium sulfate, and 2.5 g of potassium carbonate into reactors 1c, 1d, and 1e respectively.

[0080] Step 4: Add grinding balls into reactors 1b, 1c, 1d, and 1e respectively. The mass of the grinding balls is 200 g, and the ratio is 140 g of large grinding balls (diameter 10 mm), 36 g of medium grinding balls (diameter 8 mm), and 24 g of small grinding balls (diameter 5 mm).

[0081] Step 5: Cover the inner lining of the above reactors and place them into the outer shell cylinder of the reactor. Use a bench vice to tighten the reactor outer shell cover.

[0082] Step 6: Place the above five tightened reactors horizontally on the rotating shaft structure.

[0083] Step 7: Set the control panel of the reaction device, set the reaction temperature to 200 °C, the reaction time to 8 h, and the reactor rotation speed to 100 r / min.

[0084] Step 8: After the reaction is completed, take out the above reactors and cool them outside the hot air box. After cooling, use a bench vice to unscrew the reactors. Centrifuge and filter the reacted materials to achieve solid-liquid separation. Dry the slag obtained after solid-liquid separation at 110 °C for 12 h, and keep the obtained alkaline leaching solution for the next alkaline leaching. Leach the dried slag with 1 mol / L sulfuric acid at a solid-liquid ratio (g / g) of 5:1 at 30 °C for 2 h to obtain a lithium-rich solution.

[0085] Figure 4 Shows the lithium extraction rates obtained through five reactors in Example 1. The white columns represent the lithium extraction rates obtained after acid leaching and alkaline leaching of the slag, i.e., the ore phase reconstruction rates, and the gray columns represent the lithium extraction rates obtained from the alkaline leaching solution, i.e., the liquid phase leaching rates. The total lithium extraction rate is the sum of the ore phase reconstruction rate and the liquid phase leaching rate.

[0086] The total lithium extraction rates obtained by reactors 1a, 1b, 1c, 1d, and 1e were 16.15%, 19.45%, 46.29%, 64.71%, and 65.59%, respectively, of which the mineral phase reconstruction rates were 4.69%, 11.59%, 39.29%, 59.33%, and 60.60%, respectively, and the liquid phase leaching rates were 11.47%, 7.86%, 6.99%, 5.38%, and 4.99%, respectively. The results show that among the five groups of reactors, the total lithium extraction rate and mineral phase reconstruction rate obtained by reactor 1a without adding grinding balls and additives are the lowest, and the lithium extraction rate obtained by 1b under the grinding and leaching method is only 3.29% higher than that of reactor 1a. After adding the auxiliary agents sodium carbonate (1c), potassium sulfate (1d), and potassium carbonate (1e), the total lithium extraction rate and the mineral phase reconstruction rate were further increased. The total lithium extraction rate increased by 30.13%, 48.56%, and 49.44% respectively compared with the reactor 1a, and the mineral phase reconstruction rate increased by 34.61%, 54.65%, and 55.91% respectively compared with the reactor 1a. At the same time, the addition of the auxiliary agent in the reactor, under the effect of grinding and leaching, on the one hand, strengthened the spodumene mineral phase reconstruction process and improved the lithium extraction rate; on the other hand, it can also reduce the proportion of leaching into the liquid phase in the hydrothermal alkaline leaching reaction to a certain extent.

[0087] Figure 10 This is the XRD of the alkali leaching slag obtained from the five reactors in this embodiment. In the alkali leaching slag without grinding, there is still a lot of unconverted spodumene in the alkali leaching slag, and the conversion rate of spodumene ore is low; the conversion rate of spodumene ore is increased in the leaching and grinding method, and the reactor with the addition of additives further increases the mineral phase reconstruction rate of spodumene, and the proportion of lithium metasilicate in the obtained alkali leaching slag is higher.

[0088] Example 2

[0089] In the first step, 30 g of spodumene powder (100 mesh), 60 g of potassium hydroxide and 60 g of water were added to the inner lining cylinder of a reactor with a volume of 250 mL and mixed thoroughly.

[0090] In the second step, the operation of the first step is repeated three times to obtain four reaction kettles 2a, 2b, 2c, and 2d with the same ratio of ore raw materials to alkali solution.

[0091] In the third step, grinding balls are added into the reaction kettles 2b, 2c and 2d respectively. The mass of the grinding balls is 200 g, and the proportion is 140 g of large grinding balls (10 mm in diameter), 36 g of medium grinding balls (8 mm in diameter) and 24 g of small grinding balls (5 mm in diameter).

[0092] In the fourth step, 7.5 g of sodium sulfate was added to the reaction kettle 2c, and 7.5 g of sodium carbonate was added to the reaction kettle 2d.

[0093] Step 5: Cover the inner lining of the above-mentioned reactor, place it into the outer shell cylinder of the reactor, and tighten the reactor outer shell cover with a bench vice.

[0094] Step 6: Place the three reactors tightened above horizontally on the rotating shaft structure.

[0095] Step 7: Set the control panel of the reaction device, set the reaction temperature to 200 °C, the reaction time to 10 h, and the rotational speed of the reactor to 50 r / min.

[0096] Step 8 is exactly the same as that in Example 1.

[0097] Figure 5 Figure shows the comparison of the lithium extraction rate and the mineral phase reconstruction rate obtained from the three reactors in Example 2. The total lithium extraction rate obtained from the reactor 2a without grinding and additives is 20.14%. The total lithium extraction rate obtained from the reactor 2b under the grinding-while-leaching method reaches 28.47%. The total lithium extraction rate of the reactor 2c reaches 63.14% after adding the additive sodium sulfate. The total lithium extraction rate of the reactor 2d reaches 65.24% after adding the additive sodium carbonate. The mineral phase reconstruction rates of the reactors 2a, 2b, 2c, and 2d are 14.30%, 21.94%, 58.20%, and 60.20% respectively.

[0098] Example 3

[0099] Step 1: Add 40 g of spodumene ore powder (200 mesh), 60 g of sodium hydroxide, and 180 g of water into the inner lining cylinder of a reactor with a volume of 500 mL and mix well.

[0100] Step 2: Add grinding balls into the reactor, where the mass of the grinding balls is 400 g, and the ratio is 240 g of large grinding balls (diameter 10 mm), 92 g of medium grinding balls (diameter 8 mm), and 68 g of small grinding balls (diameter 5 mm).

[0101] Step 3: Repeat the operations of the previous two steps twice to obtain three inner lining cylinders 3a, 3b, and 3c of the reactor with the same addition amounts of ore powder, lye, and grinding balls.

[0102] Step 4: Add 2 g, 3 g, and 10 g of potassium sulfate into the reactors 3a, 3b, and 3c respectively.

[0103] Step 5: Cover the above three inner lining cylinders of the reactors with inner lining covers, place them into the outer shell cylinders of the reactors, and tighten the reactor outer shell covers with a bench vice.

[0104] Step 6: Place the three reactors tightened above horizontally on the rotating shaft structure.

[0105] Step 7: Set the control panel of the reaction device, set the reaction temperature to 200 °C, the reaction time to 8 h, and the rotational speed of the reactor to 100 r / min.

[0106] In the eighth step, after the reaction is completed, take out the four reactors, cool them outside the hot air box, and after cooling, use a bench vice to unscrew the reactors. Centrifuge and filter the reacted materials to achieve solid-liquid separation. Dry the slag obtained after solid-liquid separation at 110 °C for 12 h, and keep the obtained alkali leaching solution for the next alkali leaching. Leach the dried slag with 2 mol / l hydrochloric acid at a solid-liquid ratio (g / g) of 4:1 at 30 °C for 1 h to obtain a lithium-rich solution.

[0107] Figure 6 Shows the total lithium extraction rate and mineral phase reconstruction rate obtained by the reactors with different additive amounts of additives in this example. The total lithium extraction rates obtained by reactors 3a, 3b, and 3c are 42.29%, 48.74%, and 63.76% respectively, among which the mineral phase reconstruction rates are 37.35%, 44.05%, and 59.40% respectively, and the liquid-phase leaching rates are 4.94%, 4.69%, and 4.36% respectively.

[0108] Example 4

[0109] In the first step, add 20 g of spodumene ore powder (100 mesh), 30 g of sodium hydroxide, and 90 g of water to the inner liner cylinder of a 250 mL reactor and mix well.

[0110] In the second step, repeat the operation of the first step twice to obtain three reactors 4a, 4b, and 4c with the same ratio of ore raw materials to alkali solution.

[0111] In the third step, add grinding balls to reactors 4b and 4c respectively. The mass of the grinding balls is 300 g, and the ratio is 180 g of large grinding balls (diameter 10 mm), 64 g of medium grinding balls (diameter 8 mm), and 56 g of small grinding balls (diameter 5 mm).

[0112] In the fourth step, add 5 g of potassium chloride to reactor 4c.

[0113] In the fifth step, cover the inner liner of the above reactors and place them in the outer cylinder of the reactor, and use a bench vice to tighten the cover of the reactor shell.

[0114] In the sixth step, place the three tightened reactors horizontally on the rotating shaft structure.

[0115] In the seventh step, set the control panel of the reaction device, set the reaction temperature to 180 °C, the reaction time to 12 h, and the rotation speed of the reactor to 200 r / min.

[0116] The eighth step is exactly the same as in Example 1.

[0117] Figure 7Shows the total lithium extraction rate and ore phase reconstruction rate obtained from three reactors in this example. The total lithium extraction rates obtained from reactors 4a, 4b, and 4c are 10.12%, 28.08%, and 46.34% respectively, among which the ore phase reconstruction rates are 1.01%, 22.08%, and 41.02% respectively, and the liquid-phase leaching rates are 9.11%, 6.00%, and 5.32% respectively.

[0118] Example 5

[0119] First step, add 20 g of spodumene ore powder (100 mesh), 30 g of sodium hydroxide, and 90 g of water into the inner lining cylinder of a reactor with a volume of 250 mL and mix well.

[0120] Second step, repeat the operation of the first step to obtain two reactors 5a and 5b with the same ratio of ore raw materials to lye.

[0121] Third step, add grinding balls into reactors 5a and 5b respectively. The mass of the grinding balls is 200 g, and the ratio is 140 g of large grinding balls (diameter 10 mm), 36 g of medium grinding balls (diameter 8 mm), and 24 g of small grinding balls (diameter 5 mm).

[0122] Fourth step, add 2.5 g of potassium sulfate into reactor 5b.

[0123] Fifth step, cover the inner lining of the above reactors, put them into the outer shell cylinder of the reactor, and tighten the outer shell cover of the reactor with a bench vice.

[0124] Sixth step, place the two tightened reactors horizontally on the rotating shaft structure.

[0125] Seventh step, set the control panel of the reaction device, set the reaction temperature to 200 °C, the reaction time to 24 h, and the rotation speed of the reactor to 100 r / min.

[0126] The eighth step is exactly the same as in Example 1.

[0127] Figure 8 Shows the total lithium extraction rate and ore phase reconstruction rate obtained from two reactors in this example. The total lithium extraction rates obtained from reactors 5a and 5b are 45.82% and 86.38% respectively, among which the ore phase reconstruction rates are 40.21% and 83.26% respectively, and the liquid-phase leaching rates are 5.61% and 3.12% respectively. Figure 11 Shows the SEM images of the slag obtained from two reactors in this example. It can be Figure 11 seen that the slag obtained from the reactor without adding additives is in a cluster shape, and the particle surface is wrapped with fine slag, which is not conducive to the dissolution and mass transfer of minerals. While the slag of the reaction reactor with additives is in an independent fine column shape, and the particle surface is significantly smoother, further indicating that adding additives is beneficial to the progress of the reaction.

[0128] Example 6

[0129] In the first step, 20 g of spodumene ore powder (200 mesh), 30 g of sodium hydroxide, 2.5 g of K2CO3, and 90 g of water were added to the inner liner cylinder 24 of the reactor with a volume of 250 mL and thoroughly mixed.

[0130] In the second step, the operation of the first step was repeated three times to obtain four inner liner cylinders 6a, 6b, 6c, and 6d of the reactor with the same material addition amount.

[0131] In the third step, grinding balls were added to the inner liner 6a of the reactor. The mass of the grinding balls was 100 g, and the ratio was: 70 g of large grinding balls (diameter 10 mm), 18 g of medium grinding balls (diameter 8 mm), and 12 g of small grinding balls (diameter 5 mm); grinding balls were added to the inner liner 6b of the reactor. The mass of the grinding balls was 200 g, and the ratio was: 100 g of large grinding balls (diameter 10 mm), 56 g of medium grinding balls (diameter 8 mm), and 44 g of small grinding balls (diameter 5 mm); grinding balls were added to the inner liner 6c of the reactor. The mass of the grinding balls was 300 g, and the ratio was: 160 g of large grinding balls (diameter 10 mm), 86 g of medium grinding balls (diameter 8 mm), and 54 g of small grinding balls (diameter 5 mm); grinding balls were added to the inner liner 6d of the reactor. The mass of the grinding balls was 400 g, and the ratio was: 250 g of large grinding balls (diameter 10 mm), 62 g of medium grinding balls (diameter 8 mm), and 88 g of small grinding balls (diameter 5 mm). Inner liner cylinders of the reactor with different ball-to-material ratios were obtained, namely 3a (ball-to-material ratio 5:1, ratio of large, medium, and small grinding balls 70% / 18% / 12%), 3b (ball-to-material ratio 10:1, ratio of large, medium, and small grinding balls 50% / 28% / 22%), 3c (ball-to-material ratio 15:1, ratio of large, medium, and small grinding balls 53.3% / 28.6% / 18%), 3d (ball-to-material ratio 20:1, ratio of large, medium, and small grinding balls 62.5% / 15.5% / 22%).

[0132] In the fourth step, the four inner liner cylinders 24 of the reactor were covered with the inner liner cover 25 and placed in the outer shell cylinder 22 of the reactor, and the outer shell cover 23 of the reactor was tightened with the bench vice 16.

[0133] In the fifth step, the four tightened reactors were placed horizontally on the rotating shaft structure 3.

[0134] In the sixth step, the control panel of the reaction device was set, the reaction temperature was set to 200 °C, the reaction time was set to 20 h, and the rotation speed of the reactor was set to 150 r / min.

[0135] The seventh step is exactly the same as the eighth step in Example 1.

[0136] Figure 9Shows the total lithium extraction rate and mineral phase reconstruction rate obtained by the reactors with different ball-to-material ratios in this embodiment. The total lithium extraction rates obtained by reactors 6a, 6b, 6c, and 6d are 73.21%, 81.34%, 82.77%, and 84.09% respectively, among which the mineral phase reconstruction rates are 69.78%, 77.53%, 79.08%, and 80.03% respectively, and the liquid-phase leaching rates are 3.43%, 3.81%, 3.69%, and 4.06% respectively.

[0137] Example 7

[0138] First step, add materials with different ratios into the inner lining cylinders 24 (7a, 7b, 7c) of three reactors with a volume of 250 mL respectively. The specific ratios are as follows:

[0139] 7a: 30 g spodumene ore powder, 40 g sodium hydroxide, 100 g water, 3 g K2SO4;

[0140] 7b: 40 g spodumene ore powder, 50 g sodium hydroxide, 100 g water, 3 g K2SO4;

[0141] 7c: 30 g spodumene ore powder, 60 g sodium hydroxide, 110 g water, 3 g K2SO4,

[0142] Among them, the spodumene ore powder is 200 mesh.

[0143] Fully mix the materials and add grinding balls into the materials. The mass of the grinding balls is 300 g, and the ratio is: 210 g large grinding balls (diameter 10 mm), 54 g medium grinding balls (diameter 8 mm), 36 g small grinding balls (diameter 5 mm).

[0144] Second step, cover the inner lining of the reactor, place it in the outer shell cylinder 22 of the reactor, and tighten the reactor outer shell cover 23 with the bench vice 16.

[0145] Third step, place the four tightened reactors horizontally on the rotating shaft structure 3.

[0146] Fourth step, set the control panel of the reaction device, set the reaction temperature to 200 °C, the reaction time to 16 h, and the rotation speed of the reactor to 100 r / min.

[0147] Fifth step, after the reaction is completed, take out the four reactors and cool them outside the hot air box. After cooling, unscrew the reactors with the bench vice 16. Separate the solid and liquid of the reacted materials by centrifugation and filtration. Dry the slag obtained after solid-liquid separation at 110 °C for 12 h, and keep the alkali leaching solution for the next alkali leaching. Leach the dried slag with 0.75 mol / L sulfuric acid at a solid-liquid ratio (g / g) of 6:1 at 30 °C for 2 h to obtain a lithium-rich solution.

[0148] In this embodiment, the total lithium extraction rate and the mineral phase reconstruction rate obtained by the reactors under different ingredient ratios are as follows. The total lithium extraction rates obtained by reactors 7a, 7b, and 7c are 84.38%, 82.52%, and 66.95% respectively, among which the mineral phase reconstruction rates are 81.26%, 76.39%, and 48.92% respectively, and the liquid phase leaching rates are 3.12%, 6.13%, and 18.03% respectively.

[0149] This application has been described in detail so that those skilled in the art can understand the content of this application and implement it. However, this should not limit the protection scope of this application. Any equivalent changes or modifications made according to the spirit and essence of this application should be covered within the protection scope of this application.

Claims

1. A method for strengthening the phase reconstruction of spodumene ore, characterized in that, It includes the following steps: (1) Place spodumene ore in a reaction kettle, add an alkali solution, an auxiliary agent and grinding balls, and seal the reaction kettle; (2) The sealed reaction kettle lies on its side and rotates along its own axis, and the materials in the reaction kettle undergo a hydrothermal alkali leaching reaction, and the spodumene ore phase is reconstructed; (3) After the reaction ends, collect the reaction materials, and perform solid-liquid separation to obtain alkali leaching residues and an alkali leaching solution; (4) Dry the alkali leaching residues, mix the alkali leaching residues with a leaching agent to carry out an alkali leaching residue leaching reaction, and obtain a lithium-rich solution after the reaction; Among them, in step (1), the alkali solution is a sodium hydroxide solution or a potassium hydroxide solution; the auxiliary agent is potassium sulfate, potassium carbonate, potassium chloride, sodium sulfate or sodium carbonate; the particle size of the spodumene ore is 50-200 mesh; the mass ratio of the auxiliary agent to the spodumene ore is 5%-25%; the grinding balls include three different specifications of large grinding balls, medium grinding balls and small grinding balls, and the ratio of different specifications of grinding balls by mass is: large grinding balls 50%-70%; medium grinding balls 15%-28%; small grinding balls 12%-22%; In step (2), the temperature of the hydrothermal alkali leaching reaction is set at 150-200°C.

2. The method for strengthening the phase reconstruction of spodumene ore according to claim 1, wherein In step (1), the ratio of spodumene ore to alkali solution by mass parts is: Spodumene ore 20-40 parts; Sodium hydroxide 30-60 parts or potassium hydroxide 40-90 parts; Water 60-180 parts.

3. The method for strengthening the phase reconstruction of spodumene ore according to claim 1, wherein, The mass ratio of the grinding balls to the spodumene ore is (5-20):

1.

4. The method for strengthening the reconstruction of spodumene ore phase according to claim 1, wherein: When the alkali solution is a sodium hydroxide solution, the auxiliary agent is selected from potassium sulfate, potassium carbonate, potassium chloride or sodium carbonate; When the alkali solution is a potassium hydroxide solution, the auxiliary agent is selected from sodium sulfate or sodium carbonate.

5. The method for reconstructing the enhanced spodumene ore phase according to claim 1, characterized in that In step (3), the alkali leaching solution is recycled to step (1) to repeat the hydrothermal alkali leaching reaction; in step (4), the alkali leaching residues are dried, the drying temperature is 110°C, and the drying time is 0-24 h.

6. The method for strengthening spodumene ore phase reconstruction according to claim 1, wherein The leaching agent in step (4) is sulfuric acid or hydrochloric acid, and the dried alkali leaching residues are used for acid leaching; the reaction conditions for the acid leaching are set as: Reaction time 5-120 min, reaction temperature 25-30°C, the leaching agent used is 0.5-1 mol / L sulfuric acid or 1-2 mol / L hydrochloric acid, and the liquid-solid ratio is (2-10):1.

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