Method for solidifying heavy metals beryllium and thallium in process of extracting lithium from lepidolite ore

Abstract

The invention relates to the technical field of metal smelting and impurity removal, in particular to a method for solidifying heavy metal beryllium and thallium in the lithium extraction process of lepidolite ore. In the process of mixing and leaching the clinker of the lepidolite ore obtained by roasting with the sulfate method and water, the slurry is treated by adding the curing agent, and beryllium and thallium metal elements are adsorbed and retained in the leaching residues in the form of precipitates; therefore, the problem of environmental pollution caused by secondary leaching of beryllium and thallium elements in the leaching residues due to factors such as rainwater in the subsequent landfill treatment process is solved, the beryllium and thallium elements in the lithium residues are solidified in the lithium extraction process to become common solid waste, and extra resource consumption caused by secondary processing solidification after the lithium residues are output is reduced. The cost is reduced and the efficiency is improved for enterprises. Meanwhile, the curing agent used in the method is simple in component and small in dosage, and the resource cost can be saved under the condition that the beryllium and thallium curing effect is guaranteed.

Description

Technical Field

[0001] The invention relates to the technical field of metal smelting and impurity removal, and in particular to a method for solidifying heavy metals beryllium and thallium in a lithium extraction process of lepidolite ore. Background Art

[0002] As one of the main minerals for lithium extraction, lithium mica is usually subjected to a sulfate roasting method for lithium extraction reaction, which mainly roasts lithium mica with salt (sulfate, carbonate or their mixed salt) at high temperature to transform or destroy the original crystal structure of lithium mica, and the lithium ions in the lithium mica exchange with the alkali metal ions in the added salt to generate soluble lithium salts, which are then extracted into the solution through a leaching step. However, during the high-temperature roasting process, heavy metal elements such as beryllium and thallium associated with the lithium mica ore are extracted together and attached to the lithium slag. The lithium slag produced by the sulfate lithium extraction process has finer particles and a higher salt content, and there is a risk of secondary leaching of beryllium and thallium elements to pollute the environment. Therefore, how to treat lithium slag harmlessly at low cost is a problem that needs to be solved urgently.

[0003] At present, the sulfate method produces 50 to 60 tons of lithium slag for every ton of lithium carbonate salt produced. Usually, the lithium slag is landfilled as general solid waste. However, due to the increasingly prominent environmental protection issues, the environmental pollution caused by the secondary leaching of heavy metals in lithium slag has forced companies to pay attention to and carry out waste slag treatment.

[0004] Patent CN118045850A proposes a two-step treatment using a synthetic agent, wherein the waste slag and the agent are uniformly mixed and then adsorbed for treatment. The treatment cycle is 9 to 12 hours. Although beryllium and thallium can be effectively solidified in the slag, there are disadvantages such as a complex synthesis process of the solidifying agent, a long treatment cycle, and high treatment costs. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a method for solidifying heavy metal beryllium and thallium in the process of lithium extraction from lepidolite ore in view of the shortcomings of the above-mentioned prior art. In the process of mixed leaching of clinker of lepidolite ore obtained by sulfate roasting and water, a solidifying agent is added to treat the slurry, and beryllium and thallium metal elements are adsorbed and retained in the leaching residue in the form of precipitates, thereby reducing the environmental pollution problem caused by secondary leaching of beryllium and thallium elements in the leaching residue due to factors such as rainwater in the subsequent landfill treatment process.

[0006] In order to solve the above technical problems, the present invention provides a method for solidifying heavy metal beryllium and thallium in the process of extracting lithium from lepidolite ore, comprising the following steps:

[0007] S1. Prepare a curing agent: take sodium sulfide, potassium sulfide, sodium hydroxide and polysilicate aluminum iron, and mix them evenly to obtain a curing agent;

[0008] S2. Prepare raw material: take lepidolite, calcium sulfate, calcium carbonate and sodium sulfate, stir and mix them thoroughly to obtain raw material;

[0009] S3, preparing clinker: placing the raw material prepared in S2 in a preheating kiln for drying, and after drying, moving it into a rotary roasting kiln for full roasting to obtain clinker, and moving the clinker into a cooling kiln for cooling, and after the clinker is cooled, removing it for standby use;

[0010] S4, clinker leaching: taking the clinker prepared in S3 and water, adding them into a ball mill and fully crushing and ball milling them to obtain a slurry;

[0011] S5, clinker leaching: the slurry prepared in S4 is transferred to a slurry tank, and the curing agent prepared in S1 is added to the slurry tank, and lime water is added to adjust the pH value of the slurry to 10, and the slurry is fully stirred to obtain a slurry after slurrying;

[0012] S6, vacuum filtration: the slurry prepared in S5 is subjected to vacuum filtration to obtain crude brine and filter residue, and the filter residue is washed by stirring after leaching to obtain stirred filter residue;

[0013] S7, secondary stirring and washing: adding water to the stirred and washed filter residue prepared in S6, stirring for a second time to fully wash the filter residue, and obtaining a secondary washed slurry;

[0014] S8, secondary filtration: secondary reduced-pressure filtration of the secondary washing slurry prepared in S7 to obtain washing liquid and secondary leaching residue, and the secondary leaching residue is washed to obtain lithium ore solidified tailings containing solid beryllium and thallium.

[0015] According to the method for solidifying heavy metals beryllium and thallium during lithium extraction from lepidolite ore provided by the present invention: the mass ratio of sodium sulfide, potassium sulfide, sodium hydroxide and polyaluminum ferrosilicate in S1 is 1:0.6-0.2:0.2:0.1-0.05.

[0016] According to the method for solidifying heavy metals beryllium and thallium during lithium extraction from lepidolite ore provided by the present invention: the mass ratio of lepidolite, calcium sulfate, calcium carbonate and glauber's salt in S2 is 1:0.4-0.2:0.2-0.1:0.2-0.1.

[0017] According to the method for solidifying heavy metals beryllium and thallium during lithium extraction from lepidolite ore provided by the present invention: the temperature of the preheating kiln in S3 is 300-400°C, the drying time is 30 minutes, the temperature of the rotary roasting kiln is 900-1000°C, the roasting time is 1 hour, and the temperature of the clinker after cooling is 80-100°C.

[0018] According to the method for solidifying heavy metal beryllium and thallium during lithium extraction from lepidolite ore provided by the present invention: the mass ratio of clinker to water in S4 is 1:1, the rotation speed of the ball mill is 300 rpm, the ball milling time is 3 minutes, and the fineness of the slurry is -100 mesh>70%.

[0019] According to the method for solidifying heavy metals beryllium and thallium during lithium extraction from lepidolite ore provided by the present invention: the mass ratio of the slurry to the curing agent in S5 is 100:0.05, the mass fraction of the lime water is 15%, the stirring speed is 500 rpm, and the slurrying time is 30 min.

[0020] According to the method for solidifying heavy metals beryllium and thallium during lithium extraction from lepidolite ore provided by the present invention: the mass ratio of the filter residue to water in S7 is 1:0.5, and the time for the secondary stirring is 10 minutes.

[0021] Compared with the prior art, the present invention has the following advantages:

[0022] (1) In the process of leaching the clinker of lithium mica ore obtained by sulfate roasting and mixed with water, the lithium slag is solidified with a solidifying agent, stirred and washed once, and filtered twice, so that the beryllium and thallium elements of the lithium slag are solidified in the lithium extraction process to become general solid waste, thereby reducing the additional resource consumption caused by the secondary processing and solidification of the lithium slag after the output, thereby reducing costs and improving efficiency for enterprises.

[0023] (2) The curing agent used in the present invention has simple components and is used in a small amount, which can save resource costs while ensuring the curing effect of beryllium.

[0024] (3) In the preparation method provided by the present invention, various raw materials are added during the whole process of ball milling, and the raw materials are fully crushed and ball milled by the ball mill to ensure the uniformity of the added raw materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a flow chart of a method for solidifying heavy metals beryllium and thallium during lithium extraction from lepidolite ore. DETAILED DESCRIPTION

[0026] Example 1

[0027] This embodiment provides a method for solidifying heavy metals beryllium and thallium during lithium extraction from lepidolite ore, comprising the following steps:

[0028] S1. Prepare a curing agent: respectively take sodium sulfide, potassium sulfide, sodium hydroxide and polyaluminium ferrosilicate in a mass ratio of 1:0.6:0.2:0.1, and mix them evenly to obtain a curing agent;

[0029] S2. Prepare raw material: take lepidolite, calcium sulfate, calcium carbonate and sodium sulfate respectively in a mass ratio of 1:0.3:0.2:0.2, add them into a cage mixer at a speed of 500 rpm, stir for 2 minutes, and mix them thoroughly to obtain raw material;

[0030] S3, preparing clinker: placing the raw material prepared in S2 in a preheating kiln with a kiln temperature of 300-400°C for 30 minutes of drying, and after drying, moving it into a rotary roasting kiln with a kiln temperature of 900-1000°C for roasting for 1 hour to obtain clinker, and moving the clinker into a cooling kiln for cooling, and taking it out for use after the clinker temperature drops to 80-100°C;

[0031] S4, ball milling: taking the clinker prepared in S3 and water in a mass ratio of 1:1, adding them into a ball mill and crushing and ball milling them at a speed of 300 rpm for 3 minutes to obtain a slurry, wherein the fineness of the slurry is -100 mesh>70%;

[0032] S5, clinker leaching: the slurry prepared in S4 is transferred to a slurry tank by a delivery pump, and the curing agent prepared in S1 is added to the slurry tank at a mass ratio of 100:0.05 between the slurry and the curing agent prepared in S1, and at the same time, 15% by mass of lime water is added to adjust the pH value of the slurry to 10, and the slurry is stirred at a speed of 500 rpm for 30 minutes to obtain a slurry after slurrying;

[0033] S6, vacuum filtration: the slurry prepared in S5 is conveyed to a belt filter through a conveying pump for vacuum filtration to obtain crude brine and filter residue, the crude brine is stored in a brine tank, the filter residue is washed with three-stage condensed water on the belt filter and then enters a stirring and washing tank for stirring and washing to obtain a stirred and washed filter residue;

[0034] S7, secondary stirring and washing: adding water and the stirred and washed filter residue prepared in S6 at a mass ratio of 0.5:1 into the stirring and washing tank, and performing secondary stirring and washing of the filter residue for 10 minutes to obtain a secondary washed slurry;

[0035] S8, secondary filtration: the secondary washing slurry prepared in S7 is transferred to a belt filter for secondary reduced-pressure filtration to obtain a washing liquid and secondary leaching residue, the washing liquid is stored in a brine tank, and the secondary leaching residue is washed with tertiary condensed water to obtain a lithium ore solidified tailings containing solid beryllium and thallium.

[0036] In the method provided in this embodiment, various raw materials are added during the whole process of ball milling, and the raw materials are fully crushed and ball milled by the ball mill to ensure the uniformity of the added raw materials.

[0037] Comparative Example 1

[0038] This comparative example provides a preparation method that is the same as the method in Example 1 but does not add a curing agent, comprising the following steps:

[0039] S1. Prepare raw materials: take lepidolite, calcium sulfate, calcium carbonate and glauber salt respectively in a mass ratio of 1:0.3:0.2:0.2, add them into a cage mixer at a speed of 500 rpm, stir for 2 minutes, and mix them thoroughly to obtain raw materials;

[0040] S2, preparing clinker: placing the raw material prepared in S1 in a preheating kiln with a kiln temperature of 300-400°C for 30 minutes of drying, and after drying, moving it into a rotary roasting kiln with a kiln temperature of 900-1000°C for roasting for 1 hour to obtain clinker, and moving the clinker into a cooling kiln for cooling, and taking it out for use after the clinker temperature drops to 80-100°C;

[0041] S3, ball milling: take the clinker prepared in S2 and water in a mass ratio of 1:1, add them into a ball mill and grind them at a speed of 300 rpm for 3 minutes to obtain a slurry, wherein the fineness of the slurry is -100 mesh>70%;

[0042] S4, clinker leaching: the slurry prepared in S3 is transferred to a slurry tank by a delivery pump, 15% by mass of lime water is added to adjust the pH value of the slurry to 10, and then the slurry is stirred at a speed of 500 rpm for 30 minutes to obtain a slurry after slurrying;

[0043] S5, vacuum filtration: the slurry prepared in S4 is conveyed to a belt filter through a conveying pump for vacuum filtration to obtain crude brine and filter residue, the crude brine is stored in a brine tank, the filter residue is washed with three-stage condensed water on the belt filter and then enters a stirring and washing tank for stirring and washing to obtain a stirred and washed filter residue;

[0044] S6, secondary stirring and washing: adding water and the stirred and washed filter residue prepared in S5 at a mass ratio of 0.5:1 into the stirring and washing tank, and performing secondary stirring and washing of the filter residue for 10 minutes to obtain a secondary washed slurry;

[0045] S7, secondary filtration: the secondary washing slurry prepared in S6 is transferred to a belt filter for secondary reduced-pressure filtration to obtain a washing liquid and secondary leaching residue, the washing liquid is stored in a brine tank, and the secondary leaching residue is washed with tertiary condensed water to obtain solidified lithium ore tailings containing solid beryllium and thallium.

[0046] Example 2

[0047] This embodiment provides a method for solidifying heavy metals beryllium and thallium during lithium extraction from lepidolite ore, comprising the following steps:

[0048] S1. Prepare a curing agent: respectively take sodium sulfide, potassium sulfide, sodium hydroxide and polyaluminium ferrosilicate in a mass ratio of 1:0.4:0.2:0.05, mix well and obtain a curing agent;

[0049] S2. Prepare raw material: take lepidolite, calcium sulfate, calcium carbonate and sodium sulfate respectively in a mass ratio of 1:0.4:0.2:0.1, add them into a cage mixer at a speed of 500 rpm, stir for 2 minutes, and mix them thoroughly to obtain raw material;

[0050] S3, preparing clinker: placing the raw material prepared in S2 in a preheating kiln with a kiln temperature of 300-400° C. for drying for 30 minutes, moving the raw material into a rotary roasting kiln with a kiln temperature of 900-1000° C. for roasting for 1 hour to obtain clinker, moving the clinker into a cooling kiln for cooling, and taking out the clinker for standby use after the clinker temperature drops to 80-100° C.;

[0051] S4, ball milling: taking the clinker prepared in S3 and water in a mass ratio of 1:1, adding them into a ball mill and crushing and ball milling them at a speed of 300 rpm for 3 minutes to obtain a slurry, wherein the fineness of the slurry is -100 mesh>70%;

[0052] S5, clinker leaching: the slurry prepared in S4 is transferred to a slurry tank by a delivery pump, and the curing agent prepared in S1 is added to the slurry tank at a mass ratio of 100:0.05 between the slurry and the curing agent prepared in S1, and at the same time, 15% by mass of lime water is added to adjust the pH value of the slurry to 10, and the slurry is stirred at a speed of 500 rpm for 30 minutes to obtain a slurry after slurrying;

[0053] S6, vacuum filtration: the slurry prepared in S5 is conveyed to a belt filter through a conveying pump for vacuum filtration to obtain crude brine and filter residue, the crude brine is stored in a brine tank, the filter residue is washed with three-stage condensed water on the belt filter and then enters a stirring and washing tank for stirring and washing to obtain a stirred and washed filter residue;

[0054] S7, secondary stirring and washing: adding water and the stirred and washed filter residue prepared in S6 at a mass ratio of 0.5:1 into the stirring and washing tank, and performing secondary stirring and washing of the filter residue for 10 minutes to obtain a secondary washed slurry;

[0055] S8, secondary filtration: the secondary washing slurry prepared in S7 is transferred to a belt filter for secondary reduced-pressure filtration to obtain a washing liquid and secondary leaching residue, the washing liquid is stored in a brine tank, and the secondary leaching residue is washed with tertiary condensed water to obtain a lithium ore solidified tailings containing solid beryllium and thallium.

[0056] Comparative Example 2

[0057] This comparative example provides a preparation method that is the same as the method in Example 2 but does not add a curing agent, comprising the following steps:

[0058] S1. Prepare raw materials: take lepidolite, calcium sulfate, calcium carbonate and sodium sulfate in a mass ratio of 1:0.4:0.2:0.1 respectively, add them into a cage mixer at a speed of 500 rpm, stir for 2 minutes, and mix them thoroughly to obtain raw materials;

[0059] S2, preparing clinker: placing the raw material prepared in S1 in a preheating kiln with a kiln temperature of 300-400°C for 30 minutes of drying, and after drying, moving it into a rotary roasting kiln with a kiln temperature of 900-1000°C for roasting for 1 hour to obtain clinker, and moving the clinker into a cooling kiln for cooling, and taking it out for use after the clinker temperature drops to 80-100°C;

[0060] S3, ball milling: take the clinker prepared in S2 and water in a mass ratio of 1:1, add them into a ball mill and grind them at a speed of 300 rpm for 3 minutes to obtain a slurry, wherein the fineness of the slurry is -100 mesh>70%;

[0061] S4, clinker leaching: the slurry prepared in S3 is transferred to a slurry tank by a delivery pump, 15% by mass of lime water is added to adjust the pH value of the slurry to 10, and then the slurry is stirred at a speed of 500 rpm for 30 minutes to obtain a slurry after slurrying;

[0062] S5, vacuum filtration: the slurry prepared in S4 is conveyed to a belt filter through a conveying pump for vacuum filtration to obtain crude brine and filter residue, the crude brine is stored in a brine tank, the filter residue is washed with three-stage condensed water on the belt filter and then enters a stirring and washing tank for stirring and washing to obtain a stirred and washed filter residue;

[0063] S6, secondary stirring and washing: adding water and the stirred and washed filter residue prepared in S5 at a mass ratio of 0.5:1 into the stirring and washing tank, and performing secondary stirring and washing of the filter residue for 10 minutes to obtain a secondary washed slurry;

[0064] S7, secondary filtration: the secondary washing slurry prepared in S6 is transferred to a belt filter for secondary reduced-pressure filtration to obtain a washing liquid and secondary leaching residue, the washing liquid is stored in a brine tank, and the secondary leaching residue is washed with tertiary condensed water to obtain a lithium ore solidified tailings containing solid beryllium and thallium.

[0065] Example 3

[0066] This embodiment provides a method for solidifying heavy metal beryllium and thallium during lithium extraction from lepidolite ore, comprising the following steps:

[0067] S1. Prepare a curing agent: prepare sodium sulfide, potassium sulfide, sodium hydroxide and polyaluminium ferrosilicate in a mass ratio of 1:0.2:0.2:0.1 respectively, and mix them evenly to obtain a curing agent;

[0068] S2. Prepare raw material: take lepidolite, calcium sulfate, calcium carbonate and sodium sulfate respectively in a mass ratio of 1:0.2:0.1:0.1, add into a cage mixer at a speed of 500 rpm for 2 min, and mix well to obtain raw material;

[0069] S3, preparing clinker: placing the raw material prepared in S2 in a preheating kiln with a kiln temperature of 300-400° C. for drying for 30 minutes, moving the raw material into a rotary roasting kiln with a kiln temperature of 900-1000° C. for roasting for 1 hour to obtain clinker, moving the clinker into a cooling kiln for cooling, and taking out the clinker for standby use after the clinker temperature drops to 80-100° C.;

[0070] S4, ball milling: taking the clinker prepared in S3 and water in a mass ratio of 1:1, adding them into a ball mill and crushing and ball milling them at a speed of 300 rpm for 3 minutes to obtain a slurry, wherein the fineness of the slurry is -100 mesh>70%;

[0071] S5, clinker leaching: the slurry prepared in S4 is transferred to a slurry tank by a delivery pump, and the curing agent prepared in S1 is added to the slurry tank at a mass ratio of 100:0.05 between the slurry and the curing agent prepared in S1, and at the same time, 15% by mass of lime water is added to adjust the pH value of the slurry to 10, and the slurry is stirred at a speed of 500 rpm for 30 minutes to obtain a slurry after slurrying;

[0072] S6, vacuum filtration: the slurry prepared in S5 is conveyed to a belt filter through a conveying pump for vacuum filtration to obtain crude brine and filter residue, the crude brine is stored in a brine tank, the filter residue is washed with three-stage condensed water on the belt filter and then enters a stirring and washing tank for stirring and washing to obtain a stirred and washed filter residue;

[0073] S7, secondary stirring and washing: adding water and the stirred and washed filter residue prepared in S6 at a mass ratio of 0.5:1 into the stirring and washing tank, and performing secondary stirring and washing of the filter residue for 10 minutes to obtain a secondary washed slurry;

[0074] S8, secondary filtration: the secondary washing slurry prepared in S7 is transferred to a belt filter for secondary reduced-pressure filtration to obtain a washing liquid and secondary leaching residue, the washing liquid is stored in a brine tank, and the secondary leaching residue is washed with tertiary condensed water to obtain a lithium ore solidified tailings containing solid beryllium and thallium.

[0075] Comparative Example 3

[0076] This comparative example provides a preparation method that is the same as the method in Example 3 but does not add a curing agent, comprising the following steps:

[0077] S1. Prepare raw materials: take lepidolite, calcium sulfate, calcium carbonate and sodium sulfate in a mass ratio of 1:0.2:0.1:0.1 respectively, add them into a cage mixer at a speed of 500 rpm, stir for 2 minutes, and mix them thoroughly to obtain raw materials;

[0078] S2, preparing clinker: placing the raw material prepared in S1 in a preheating kiln with a kiln temperature of 300-400°C for 30 minutes of drying, and after drying, moving it into a rotary roasting kiln with a kiln temperature of 900-1000°C for roasting for 1 hour to obtain clinker, and moving the clinker into a cooling kiln for cooling, and taking it out for use after the clinker temperature drops to 80-100°C;

[0079] S3, ball milling: take the clinker prepared in S2 and water in a mass ratio of 1:1, add them into a ball mill and grind them at a speed of 300 rpm for 3 minutes to obtain a slurry, wherein the fineness of the slurry is -100 mesh>70%;

[0080] S4, clinker leaching: the slurry prepared in S3 is transferred to a slurry tank by a delivery pump, 15% by mass of lime water is added to adjust the pH value of the slurry to 10, and then the slurry is stirred at a speed of 500 rpm for 30 minutes to obtain a slurry after slurrying;

[0081] S5, vacuum filtration: the slurry prepared in S4 is conveyed to a belt filter through a conveying pump for vacuum filtration to obtain crude brine and filter residue, the crude brine is stored in a brine tank, the filter residue is washed with three-stage condensed water on the belt filter and then enters a stirring and washing tank for stirring and washing to obtain a stirred and washed filter residue;

[0082] S6, secondary stirring and washing: adding water and the stirred and washed filter residue prepared in S5 at a mass ratio of 0.5:1 into the stirring and washing tank, and performing secondary stirring and washing of the filter residue for 10 minutes to obtain a secondary washed slurry;

[0083] S7, secondary filtration: the secondary washing slurry prepared in S6 is transferred to a belt filter for secondary reduced-pressure filtration to obtain a washing liquid and secondary leaching residue, the washing liquid is stored in a brine tank, and the secondary leaching residue is washed with tertiary condensed water to obtain solidified lithium ore tailings containing solid beryllium and thallium.

[0084] Example 4

[0085] The solidified lithium ore tailings prepared in Examples 1 to 3 and Comparative Examples 1 to 3 were taken respectively, and each Example and Comparative Example was repeated three times to obtain three groups of samples. The lithium slag was subjected to a leaching test according to the "Solid Waste Leaching Toxicity Leaching Method Horizontal Oscillation Method" in the HJ557-2010 standard. The beryllium and thallium content of the leaching solution was detected using an ICP-MS inductively coupled mass spectrometer. The test results are shown in Table 1 below:

[0086] Table 1 Beryllium and Thallium Content Test Table

[0087]

[0088]

[0089] The results of the beryllium and thallium element content detection in this embodiment are lower than the national and local standards, achieving the purpose of solidifying the heavy metals beryllium and thallium.

[0090] The above is only a preferred embodiment of the present invention and does not limit the present invention in any way. Any simple modification, change and equivalent change made to the above embodiment according to the technical essence of the invention still falls within the protection scope of the technical solution of the present invention.

Claims

1. A method for solidifying heavy metal beryllium and thallium in the process of lithium extraction from lepidolite ore, characterized in that: The following steps are involved: S1. Prepare a curing agent: take sodium sulfide, potassium sulfide, sodium hydroxide and polysilicate aluminum iron, and mix them evenly to obtain a curing agent; S2. Prepare raw material: take lepidolite, calcium sulfate, calcium carbonate and sodium sulfate, stir and mix them thoroughly to obtain raw material; S3, preparing clinker: placing the raw material prepared in S2 in a preheating kiln for drying, and after drying, moving it into a rotary roasting kiln for full roasting to obtain clinker, and moving the clinker into a cooling kiln for cooling, and after the clinker is cooled, removing it for standby use; S4, ball milling: taking the clinker prepared in S3 and water, adding them into a ball mill and fully crushing and ball milling them to obtain a slurry; S5, clinker leaching: the slurry prepared in S4 is transferred to a slurry tank, and the curing agent prepared in S1 is added to the slurry tank, and lime water is added to adjust the pH value of the slurry to 10, and the slurry is fully stirred to obtain a slurry after slurrying; S6, vacuum filtration: vacuum filtration is performed on the slurry prepared in S5 to obtain crude brine and filter residue, and the filter residue is washed by stirring after leaching to obtain stirred filter residue; S7, secondary stirring and washing: adding water to the stirred and washed filter residue prepared in S6, stirring for a second time to fully wash the filter residue, and obtaining a secondary washed slurry; S8, secondary filtration: secondary reduced-pressure filtration of the secondary washing slurry prepared in S7 to obtain washing liquid and secondary leaching residue, and the secondary leaching residue is washed to obtain lithium ore solidified tailings containing solid beryllium and thallium.

2. The method for solidifying heavy metal beryllium and thallium in the lithium extraction process of lepidolite ore according to claim 1, characterized in that: The mass ratio of sodium sulfide, potassium sulfide, sodium hydroxide and polysilicate aluminum iron in S1 is 1:0.6-0.2:0.2:0.1-0.

05.

3. The method for solidifying heavy metal beryllium and thallium in the lithium extraction process of lepidolite ore according to claim 1, characterized in that: The mass ratio of lepidolite, calcium sulfate, calcium carbonate and glauber's salt described in S2 is 1:0.4-0.2:0.2-0.1:0.2-0.

1.

4. The method for solidifying heavy metal beryllium and thallium in the lithium extraction process of lepidolite ore according to claim 1, characterized in that: The temperature of the preheating kiln in S3 is 300-400°C, the drying time is 30 minutes, the temperature of the rotary roasting kiln is 900-1000°C, the roasting time is 1 hour, and the temperature of the clinker after cooling is 80-100°C.

5. The method for solidifying heavy metal beryllium and thallium in the lithium extraction process of lepidolite ore according to claim 1, characterized in that: The mass ratio of the clinker to water in S4 is 1:1, the rotation speed of the ball mill is 300 rpm, the ball milling time is 3 min, and the fineness of the slurry is -100 mesh>70%.

6. The method for solidifying heavy metal beryllium and thallium in the lithium extraction process of lepidolite ore according to claim 1, characterized in that: In S5, the mass ratio of the slurry to the curing agent is 100:0.05, the mass fraction of the lime water is 15%, the stirring speed is 500 rpm, and the slurrying time is 30 min.

7. The method for solidifying heavy metal beryllium and thallium in the lithium extraction process of lepidolite ore according to claim 1, characterized in that: The mass ratio of the filter residue to water in S7 is 1:0.5, and the time of the secondary stirring is 10 minutes.

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