Lepidolite slag resourceful treatment method, composite admixture and application

Abstract

The invention discloses a lepidolite slag resourceful treatment method, a composite admixture and application, and relates to the technical field of resource recycling, the method comprises the following steps: mixing an alkali treatment agent with water to obtain an alkali treatment mixture, adding the alkali treatment mixture into lithium slag, and stirring and calcining to obtain dried lithium slag; mixing and stirring the lithium slag and a sulfur-fixing agent, and drying for later use; mixing and grinding the lithium slag subjected to sulfur fixation pretreatment with at least one industrial smelting slag to obtain mixed powder; adding an exciting agent into the mixed powder, and mixing and stirring to obtain a composite admixture; and mixing the composite admixture with a cementing material and gravel, adding water, stirring, and curing to obtain the mortar test block. Alkali conversion and sulfur fixation pretreatment are carried out on the lepidolite residues, so that the high-activity composite admixture is obtained and can be used for construction of buildings and roads, resource utilization of the lepidolite residues can be achieved, and the environment is obviously improved.

Description

Technical Field

[0001] The present invention relates to the technical field of resource recycling, and in particular to a lepidolite slag resource treatment method, a composite admixture and an application thereof. Background Art

[0002] With the rapid popularization of new energy vehicles, the demand for lithium batteries has also increased rapidly. The main raw materials for making lithium batteries include lepidolite, which is mainly used to extract lithium elements for the production of lithium batteries.

[0003] After lithium is extracted from lepidolite, a series of treatments based on the lithium element are carried out to obtain lithium carbonate. The production of lithium carbonate is also accompanied by the generation of lithium slag. The current large-scale storage of lithium slag not only seriously affects the production of lithium carbonate companies, but also poses a safety hazard to the local environment and ecology.

[0004] In the prior art, lithium slag is usually treated by a single method of reducing sulfur or reducing alkali. The sulfur reduction and alkali reduction treatments are simply neutralization reactions, and the useful substances contained in the lithium slag are not fully utilized. The lithium slag cannot be fully recycled and is discarded. Summary of the Invention

[0005] In view of the deficiencies in the prior art, the present invention aims to provide a method for resource-based treatment of lepidolite slag, a composite admixture and its application. By subjecting the lepidolite slag to alkali conversion and sulfur fixation pretreatment, a highly active composite admixture is obtained, which can be used in the construction of buildings and roads. The present invention can achieve resource utilization of the lepidolite slag and significantly improve the environment.

[0006] A first aspect of the present invention is to provide a method for recycling lepidolite slag, the method comprising:

[0007] mixing an alkali treatment agent with water to obtain an alkali treatment mixture, adding the alkali treatment mixture to lithium slag, stirring, and calcining to obtain dried lithium slag;

[0008] The lithium slag is mixed with the sulfur-fixing agent, stirred, and dried for later use;

[0009] mixing and grinding the lithium slag after sulfur fixation pretreatment with at least one industrial smelting slag to obtain a mixed powder;

[0010] adding an activator to the mixed powder, mixing and stirring to obtain a composite admixture;

[0011] The composite admixture is mixed with a cementitious material and sand and gravel, and water is added and stirred, and the mixture is solidified to obtain a mortar test block.

[0012] According to one aspect of the above technical solution, an alkali treatment agent is mixed with water to obtain an alkali treatment mixture, and the alkali treatment mixture is added to lithium slag, stirred, and calcined to obtain a dry lithium slag, comprising:

[0013] mixing sodium carbonate, calcium carbonate or a mixture thereof with water to obtain an alkali treatment mixture;

[0014] adding the alkali treatment mixture into lithium slag and stirring;

[0015] The alkali-treated lithium slag is taken out and calcined at 700° C.-850° C. for 1 h-3 h to obtain dry lithium slag.

[0016] According to one aspect of the above technical solution, the step of mixing and stirring the lithium slag with the sulfur-fixing agent and drying for standby use comprises:

[0017] Mixing and stirring the lithium slag with sodium metaaluminate, hydrocalumite or a mixture thereof;

[0018] The lithium slag is taken out and dried for later use.

[0019] According to one aspect of the above technical solution, the step of mixing and grinding the lithium slag after the sulfur fixation pretreatment with at least one industrial smelting slag to obtain a mixed powder includes:

[0020] The lithium slag after sulfur fixation pretreatment is mixed with mineral powder and fly ash to obtain mixed slag;

[0021] The mixed slag is ground to obtain a mixed powder.

[0022] According to one aspect of the above technical solution, the mass ratio of lithium slag to mineral powder and fly ash is 3-9:1-8:1-5.

[0023] According to one aspect of the above technical solution, the specific surface area of ​​the mixed powder is 400m 2 / kg-500m 2 / kg.

[0024] According to one aspect of the above technical solution, the step of adding an activator to the mixed powder and mixing and stirring to obtain a composite admixture includes:

[0025] One or more of sodium metasilicate, sodium silicate and sodium hexametaphosphate are added to the mixed powder, mixed and stirred to obtain a composite admixture.

[0026] According to one aspect of the above technical solution, the mixing ratio of the mixed powder to the stimulator is 5-10:1.

[0027] Another aspect of the present invention is to provide a composite admixture prepared by the method described in the above technical solution.

[0028] The third aspect of the present invention is to provide an application of the composite admixture in the above technical solution in the production of mortar test blocks.

[0029] Compared with the prior art, the resource processing method of the lepidolite slag of the present invention is adopted. After the lithium slag is subjected to alkali conversion and sulfur fixation pretreatment to meet relevant standards for building materials, the lepidolite slag is then ground and modified to prepare an alkali-converted and sulfur-fixed pretreated lepidolite slag and a high-activity composite admixture. The present invention can not only improve the utilization rate of lithium slag in engineering fields such as buildings and roads, but also open up new paths in the fields of environment, mineral processing, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the following description of the embodiments with reference to the accompanying drawings, in which:

[0031] Figure 1 The figure is a flow chart of a method for recycling lepidolite slag according to an embodiment of the present invention. DETAILED DESCRIPTION

[0032] To make the objectives, features, and advantages of the present invention more readily apparent, the following detailed description of specific embodiments of the present invention is provided in conjunction with the accompanying drawings. The accompanying drawings illustrate several embodiments of the present invention. However, the present invention may be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and comprehensive understanding of the present invention.

[0033] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this invention pertains. The terms used in this specification of the present invention are for the purpose of describing specific embodiments only and are not intended to limit the present invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0034] In the prior art, lithium slag is typically treated with either a single sulfur reduction or alkali reduction method. These treatments simply involve neutralization reactions, leaving the useful substances in the slag unutilized and unused. Therefore, the slag cannot be fully recycled and is discarded. To address this issue, the method disclosed herein transforms and utilizes the alkali in the slag through a physical-chemical reaction, solidifies the sulfur to meet building material standards, and then grinds and modifies the slag to produce a lepidolite slag alkali conversion and sulfur fixation pretreatment, along with a highly active composite admixture, for example, for making mortar test blocks.

[0035] In order to achieve the above object, the first aspect of the present invention is to provide a method for recycling lepidolite slag. Figure 1 , the method comprises steps S1 to S5:

[0036] Step S1, mixing an alkali treatment agent with water to obtain an alkali treatment mixture, adding the alkali treatment mixture to lithium slag, stirring, and calcining to obtain dried lithium slag;

[0037] Step S2, mixing the lithium slag with a sulfur-fixing agent, and drying them for later use;

[0038] Step S3, mixing and grinding the lithium slag after the sulfur fixation pretreatment with at least one industrial smelting slag to obtain a mixed powder;

[0039] Step S4, adding an activator to the mixed powder and mixing and stirring to obtain a composite admixture;

[0040] Step S5: mixing the composite admixture with the cementitious material and sand and gravel, adding water and stirring, and solidifying to obtain a mortar test block.

[0041] Among them, mortar test blocks are widely used in construction tests and engineering quality supervision tests in highway projects, railway projects, construction sites, commercial concrete mixing stations, water conservancy projects and other fields.

[0042] Furthermore, the steps of mixing an alkali treatment agent with water to obtain an alkali treatment mixture, adding the alkali treatment mixture to lithium slag, stirring, and calcining to obtain dry lithium slag include:

[0043] mixing sodium carbonate, calcium carbonate or a mixture thereof with water to obtain an alkali treatment mixture;

[0044] adding the alkali treatment mixture into lithium slag and stirring;

[0045] The alkali-treated lithium slag is taken out and calcined at 700° C.-850° C. for 1 h-3 h to obtain dry lithium slag.

[0046] Specifically, under calcination conditions of 700℃-850℃, lithium slag reacts with carbonates to produce substances such as sodium aluminate, potassium aluminate, and sodium metasilicate. The generated substances can not only provide favorable conditions for sulfur fixation, but also react under the alkaline conditions of cement hydration to produce substances with cementing ability.

[0047] Furthermore, the lithium slag is mixed with a sulfur-fixing agent, stirred, and dried for standby use, comprising:

[0048] Mixing and stirring the lithium slag with sodium metaaluminate, hydrocalumite or a mixture thereof;

[0049] The lithium slag is taken out and dried for later use.

[0050] Specifically, the lithium slag after alkali conversion treatment contains Ca 2+ 、SO4 2- Plasma will react with sodium aluminate, hydrocalumite or a mixture thereof to form ettringite. At the same time, the same reaction will occur between the alkali-converted lithium slag itself, thereby fixing the sulfur contained in the lithium slag.

[0051] Furthermore, the step of mixing and grinding the lithium slag after the sulfur fixation pretreatment with at least one industrial smelting slag to obtain a mixed powder comprises:

[0052] The lithium slag after sulfur fixation pretreatment is mixed with mineral powder and fly ash to obtain mixed slag;

[0053] The mixed slag is ground to obtain a mixed powder.

[0054] Specifically, after grinding and modification, the molecular bonds of the lithium slag are broken and reorganized, thereby greatly improving the activity of the lithium slag and enabling it to fully participate in the hydration reaction in concrete.

[0055] Furthermore, the mass ratio of lithium slag to mineral powder and fly ash is 3-9:1-8:1-5.

[0056] Furthermore, the specific surface area of ​​the mixed powder is 400m 2 / kg-500m 2 / kg.

[0057] Furthermore, the step of adding an activator to the mixed powder and mixing and stirring to obtain a composite admixture includes:

[0058] One or more of sodium metasilicate, sodium silicate and sodium hexametaphosphate are added to the mixed powder, mixed and stirred to obtain a composite admixture.

[0059] Furthermore, the mixing ratio of the mixed powder to the stimulator is 5-10:1.

[0060] The second aspect of the present invention is to provide a composite admixture prepared by the method described in the above technical solution.

[0061] Compared with the prior art, the resource processing method of the lepidolite slag of the present invention is adopted. After the lithium slag is subjected to alkali conversion and sulfur fixation pretreatment to meet relevant standards for building materials, the lepidolite slag is then ground and modified to prepare an alkali-converted and sulfur-fixed pretreated lepidolite slag and a high-activity composite admixture. The present invention can not only improve the utilization rate of lithium slag in engineering fields such as buildings and roads, but also open up new paths in the fields of environment, mineral processing, etc.

[0062] Example 1

[0063] The first embodiment of the present invention provides a method for recycling lepidolite slag. The method shown in this embodiment includes:

[0064] Step S11: mixing an alkali treatment agent with water to obtain an alkali treatment mixture, adding the alkali treatment mixture to lithium slag and stirring evenly, and calcining at 700° C.-850° C. for 1 h-3 h to obtain dried lithium slag.

[0065] In this embodiment, the alkali treatment agent is a mixture of sodium carbonate and calcium carbonate.

[0066] Step S12, adding a sulfur-fixing agent to the dried lithium slag, mixing the lithium slag and the sulfur-fixing agent, stirring, and drying for standby use.

[0067] In this embodiment, the sulfur-fixing agent is a mixture of sodium metaaluminate and hydrocalumite.

[0068] Step S13: Mix the lithium slag after sulfur fixation pretreatment with ore powder and fly ash according to a preset mass ratio and grind them to a specific surface area of ​​about 400m 2 / kg-500m 2 / kg.

[0069] In this embodiment, the mass ratio of lithium slag to mineral powder and fly ash is 2:1:1.

[0070] Step S14: adding an activator to the mixed powder, mixing and stirring uniformly to obtain a composite admixture.

[0071] In this embodiment, the activator is a mixture of sodium metasilicate, sodium silicate and sodium hexametaphosphate.

[0072] Step S15: mixing the composite admixture with the cementitious material and sand and gravel, adding water and stirring, and solidifying to obtain a mortar test block.

[0073] Example 2

[0074] The second embodiment of the present invention also provides a method for recycling lepidolite slag. The method shown in this embodiment includes:

[0075] Step S21 , mixing an alkali treatment agent with water to obtain an alkali treatment mixture, adding the alkali treatment mixture to lithium slag and stirring evenly, and calcining at 700° C.-850° C. for 1 h-3 h to obtain dried lithium slag.

[0076] In this embodiment, the alkali treatment agent is a mixture of sodium carbonate and calcium carbonate.

[0077] Step S22, adding a sulfur-fixing agent to the dried lithium slag, mixing the lithium slag and the sulfur-fixing agent, stirring, and drying for standby use.

[0078] In this embodiment, the sulfur-fixing agent is a mixture of sodium metaaluminate and hydrocalumite.

[0079] Step S23: The lithium slag after the sulfur fixation pretreatment is mixed with the ore powder and fly ash according to a preset mass ratio, and ground to a specific surface area of ​​about 400m 2 / kg-500m 2 / kg.

[0080] In this embodiment, the mass ratio of lithium slag to mineral powder and fly ash is 8:7:5.

[0081] Step S24, adding an activator to the mixed powder, mixing and stirring uniformly to obtain a composite admixture.

[0082] In this embodiment, the activator is a mixture of sodium metasilicate, sodium silicate and sodium hexametaphosphate.

[0083] Step S25: mixing the composite admixture with the cementitious material and sand and gravel, adding water and stirring, and solidifying to obtain a mortar test block.

[0084] Example 3

[0085] The third embodiment of the present invention also provides a method for recycling lepidolite slag. The method shown in this embodiment includes:

[0086] Step S31 , mixing an alkali treatment agent with water to obtain an alkali treatment mixture, adding the alkali treatment mixture to lithium slag and stirring evenly, and calcining at 700° C.-850° C. for 1 h-3 h to obtain dried lithium slag.

[0087] In this embodiment, the alkali treatment agent is a mixture of sodium carbonate and calcium carbonate.

[0088] Step S32, adding a sulfur-fixing agent to the dried lithium slag, mixing the lithium slag and the sulfur-fixing agent, stirring, and drying for standby use.

[0089] In this embodiment, the sulfur-fixing agent is a mixture of sodium metaaluminate and hydrocalumite.

[0090] Step S33: Mix the lithium slag after sulfur fixation pretreatment with ore powder and fly ash according to a preset mass ratio and grind them to a specific surface area of ​​about 400m 2 / kg-500m 2 / kg.

[0091] In this embodiment, the mass ratio of lithium slag to mineral powder and fly ash is 9:8:3.

[0092] Step S34, adding an activator to the mixed powder, mixing and stirring uniformly to obtain a composite admixture.

[0093] In this embodiment, the activator is a mixture of sodium metasilicate, sodium silicate and sodium hexametaphosphate.

[0094] Step S35: mixing the composite admixture with the cementitious material and sand and gravel, adding water and stirring, and solidifying to obtain a mortar test block.

[0095] Example 4

[0096] The fourth embodiment of the present invention also provides a method for recycling lepidolite slag. The method shown in this embodiment includes:

[0097] Step S41 , mixing an alkali treatment agent with water to obtain an alkali treatment mixture, adding the alkali treatment mixture to lithium slag and stirring evenly, and calcining at 700° C.-850° C. for 1 h-3 h to obtain dried lithium slag.

[0098] In this embodiment, the alkali treatment agent is a mixture of sodium carbonate and calcium carbonate.

[0099] Step S42, adding a sulfur-fixing agent to the dried lithium slag, mixing the lithium slag and the sulfur-fixing agent, stirring, and drying for standby use.

[0100] In this embodiment, the sulfur-fixing agent is a mixture of sodium metaaluminate and hydrocalumite.

[0101] Step S43: Mix the lithium slag after sulfur fixation pretreatment with ore powder and fly ash according to a preset mass ratio and grind them to a specific surface area of ​​about 400m 2 / kg-500m 2 / kg.

[0102] In this embodiment, the mass ratio of lithium slag to mineral powder and fly ash is 3:5:2.

[0103] Step S44: adding an activator to the mixed powder, mixing and stirring uniformly to obtain a composite admixture.

[0104] In this embodiment, the activator is a mixture of sodium metasilicate, sodium silicate and sodium hexametaphosphate.

[0105] Step S45: mixing the composite admixture with the cementitious material and sand and gravel, adding water and stirring, and solidifying to obtain a mortar test block.

[0106] Example 5

[0107] The fifth embodiment of the present invention also provides a method for recycling lepidolite slag. The method shown in this embodiment includes:

[0108] Step S51 , mixing an alkali treatment agent with water to obtain an alkali treatment mixture, adding the alkali treatment mixture to lithium slag and stirring evenly, and then calcining at 700° C.-850° C. for 1 h-3 h to obtain dried lithium slag.

[0109] In this embodiment, the alkali treatment agent is a mixture of sodium carbonate and calcium carbonate.

[0110] Step S52: adding a sulfur-fixing agent to the dried lithium slag to mix the lithium slag and the sulfur-fixing agent, stirring the mixture, and drying the mixture for later use.

[0111] In this embodiment, the sulfur-fixing agent is a mixture of sodium metaaluminate and hydrocalumite.

[0112] Step S53: Mix the lithium slag after sulfur fixation pretreatment with ore powder and fly ash according to a preset mass ratio and grind them to a specific surface area of ​​about 400m 2 / kg-500m 2 / kg.

[0113] In this embodiment, the mass ratio of lithium slag to mineral powder and fly ash is 5:2:3.

[0114] Step S54: adding an activator to the mixed powder, mixing and stirring uniformly to obtain a composite admixture.

[0115] In this embodiment, the activator is a mixture of sodium metasilicate, sodium silicate and sodium hexametaphosphate.

[0116] Step S55: mixing the composite admixture with the cementitious material and sand and gravel, adding water and stirring, and solidifying to obtain a mortar test block.

[0117] Table 1 is a comparison table of the activity index of mortar specimens.

[0118] Table 1

[0119]

[0120] According to Table 1 and the embodiments shown in the present invention, the lithium slag is subjected to alkali conversion and solid sulfur pretreatment by the method shown in this embodiment, and is mixed with other industrial smelting slag and ground into powder, and then mixed with an activator to obtain a composite admixture, which can be used for the production of mortar test blocks. By producing high-performance mortar test blocks, its compressive strength and activity index can be effectively improved. As shown in Example 1, its compressive strength reaches 56 MPa, which is 8 MPa higher than that of the benchmark cement, and its activity index reaches 116.7%, which is 16.7% higher than that of the benchmark cement. This embodiment can fully utilize the remaining resources of the lithium slag by resource processing and adding it to the production of mortar test blocks, and can also achieve good benefits in the application and detection of building materials.

[0121] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "examples," "specific examples," or "some examples" means that a specific feature, structure, material, or characteristic described in conjunction with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0122] The above-described embodiments merely illustrate several implementations of the present invention. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art would be able to make numerous modifications and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

Claims

1. A method for recycling lithium mica slag, characterized in that: The method comprises: Mixing an alkali treatment agent with water to obtain an alkali treatment mixture, adding the alkali treatment mixture to lithium slag, stirring, and calcining to obtain dried lithium slag; The lithium slag is mixed with the sulfur-fixing agent, stirred, and dried for later use; The lithium slag after the sulfur fixation pretreatment is mixed and ground with at least one industrial smelting slag to obtain a mixed powder; Adding an activator to the mixed powder and mixing and stirring to obtain a composite admixture; The composite admixture is mixed with cementitious materials and sand and gravel, and water is added for stirring, and the mixture is solidified to obtain a mortar test block.

2. The method for recycling lepidolite slag according to claim 1, wherein: The steps of mixing an alkali treatment agent with water to obtain an alkali treatment mixture, adding the alkali treatment mixture to lithium slag, stirring, and calcining to obtain dry lithium slag include: Mixing sodium carbonate, calcium carbonate or a mixture of the two with water to obtain an alkali treatment mixture; Adding the alkali treatment mixture into lithium slag and stirring; The alkali-treated lithium slag is taken out and calcined at 700°C-850°C for 1h-3h to obtain dry lithium slag.

3. The method for recycling lithium mica slag according to claim 1, wherein: The step of mixing and stirring the lithium slag with the sulfur-fixing agent and drying for later use comprises: The lithium slag is mixed and stirred with sodium aluminate, hydrocalumite or a mixture thereof; The lithium slag is taken out, dried and set aside.

4. The method for recycling lepidolite slag according to claim 1, wherein: The step of mixing and grinding the lithium slag after sulfur fixation pretreatment with at least one industrial smelting slag to obtain a mixed powder comprises: The lithium slag after the sulfur fixation pretreatment is mixed with mineral powder and fly ash to obtain mixed slag; The mixed slag is ground to obtain a mixed powder.

5. The method for recycling lithium mica slag according to claim 4, wherein: The mass ratio of lithium slag to mineral powder and fly ash is 3-9:1-8:1-5.

6. The method for recycling lithium mica slag according to claim 4, wherein: The specific surface area of ​​the mixed powder is 400m 2 / kg-500m 2 / kg.

7. The method for recycling lepidolite slag according to claim 1, wherein: The step of adding an activator to the mixed powder and mixing and stirring to obtain a composite admixture comprises: One or more of sodium metasilicate, sodium silicate and sodium hexametaphosphate are added to the mixed powder, mixed and stirred to obtain a composite admixture.

8. The method for recycling lepidolite slag according to any one of claim 7, wherein: The mixing ratio of the mixed powder to the activator is 5-10:

1.

9. A composite admixture, characterized in that: The method is prepared by any one of claims 1 to 8.

10. Use of the composite admixture as claimed in claim 9 in making mortar test blocks.

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