A shell reinforcing method of lithium slag-based non-burning lightweight aggregate and lithium slag-based non-burning lightweight aggregate after shell reinforcement

Abstract

The application discloses a shell reinforcing method of lithium residue-based non-burning light aggregate and the lithium residue-based non-burning light aggregate after shell reinforcing. The shell reinforcing method comprises the following steps: S1, mixing lithium smelting residue, solid waste and auxiliary materials to obtain mixed materials; S2, performing initial granulation treatment on the mixed materials to obtain green balls; S3, performing round-pot granulation treatment on the green balls to obtain shell reinforced green balls; and S4, performing curing treatment on the shell reinforced green balls to obtain the lithium residue-based non-burning light aggregate. According to the shell reinforcing method, after the green balls are obtained through initial granulation, the round-pot granulation treatment is performed, the special granulation mode is used, the outer shell of the lithium residue-based non-burning light aggregate is mechanically reinforced, the compactness of the surface of the lithium residue-based non-burning light aggregate is improved under the condition of ensuring the same bulk density, and thus the cylinder pressure strength is improved and the water absorption rate is reduced.

Description

Technical Field

[0001] This invention belongs to the field of solid waste resource utilization and environmental protection materials technology, and relates to a shell strengthening method for lithium slag-based non-burning lightweight aggregate and the shell-strengthened lithium slag-based non-burning lightweight aggregate. Background Technology

[0002] With the rapid development of new energy sources, the demand for lithium salt products is also increasing. Lithium slag is a solid waste generated during the lithium extraction process from lithium ore. As a core lightweight component of concrete, lightweight aggregates have attracted much attention for their environmentally friendly preparation technology. Therefore, the preparation of lightweight aggregates based on lithium slag has become a mainstream trend. However, traditional sintered lightweight aggregates have drawbacks such as high energy consumption (calcination temperature > 1000℃) and large carbon emissions. While non-fired lightweight aggregates can reduce energy consumption, they generally face disadvantages such as insufficient shell strength, surface powdering, and high water absorption. Therefore, how to improve the compressive strength of lithium slag-based non-fired lightweight aggregates and reduce their water absorption is of great significance for the efficient application of lithium slag-based non-fired lightweight aggregates.

[0003] Non-fired lightweight aggregates, with their light weight, high strength, and excellent thermal insulation properties, are widely used in building aggregates, thermal insulation materials, ecological greening, and toilet backfilling. Currently, there are processes for preparing non-fired lightweight aggregates using lithium slag as the main raw material. CN117185690A discloses lithium slag-based non-fired lightweight ceramsite, its preparation method, and applications. Using spodumene lithium extraction residue as the basic raw material, the proportions are: 60-80 parts lithium slag, 10-20 parts cement, 8-15 parts quicklime, 3-8 parts alkali activator, 1-6 parts foaming agent, and 12-20 parts water. The resulting lithium slag-based non-fired lightweight aggregate has a maximum compressive strength of 9.41 MPa and a water absorption rate of 11.4%, requiring the addition of large amounts of cement and quicklime to form the main cementitious system. However, its excessively high water absorption rate affects its later performance. CN118908610A is a modified natural lightweight aggregate, made by mixing phosphogypsum, fly ash, slag powder and quicklime for the outer shell. It reduces the bulk density of ceramsite and increases its compressive strength by using an inner and outer shell structure. However, its interior is composed of modified natural lightweight aggregate, and there are component differences between the core and shell structures, which can easily lead to defects such as core-shell separation and reduced strength.

[0004] Therefore, improving the density of lithium slag-based non-fired lightweight aggregates without affecting their bulk density is a technical issue that urgently needs to be explored. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the present invention aims to provide a shell strengthening method for lithium slag-based non-fired lightweight aggregates and the shell-strengthened lithium slag-based non-fired lightweight aggregates. The shell strengthening method provided by the present invention involves initial granulation to obtain raw material pellets, followed by pot granulation. Utilizing a special granulation method, the outer shell of the lithium slag-based non-fired lightweight aggregate is mechanically strengthened. While maintaining the same bulk density, this increases the surface compactness of the lithium slag-based non-fired lightweight aggregate, thereby improving its compressive strength and reducing water absorption.

[0006] To achieve this objective, the present invention adopts the following technical solution:

[0007] In a first aspect, the present invention provides a method for shell strengthening of lithium slag-based non-burning lightweight aggregates, the shell strengthening method comprising the following steps:

[0008] S1. Mix lithium smelting slag, solid waste and auxiliary materials to obtain a mixture;

[0009] S2. Perform initial granulation treatment on the mixture to obtain raw material pellets;

[0010] S3. The raw material pellets are subjected to round pot granulation to obtain shell-reinforced raw material pellets;

[0011] S4. The shell-reinforced raw material balls are cured to obtain the lithium slag-based non-fired lightweight aggregate.

[0012] In the shell strengthening method provided by the present invention, after obtaining the initial raw material balls, the round pot granulation process is continued. A special granulation method is used to mechanically strengthen the shell of the lithium slag-based non-burning lightweight aggregate. While ensuring the same bulk density, the density of the surface of the lithium slag-based non-burning lightweight aggregate is improved by adjusting the phase and elemental composition of the shell, thereby improving its compressive strength and reducing its water absorption rate.

[0013] It should be noted that the lithium smelting slag in this invention is a solid waste generated during the lithium extraction process from lithium ore. The specific source is not unique. For example, it can be spodumene smelting slag, lepidolite smelting slag, or other solid waste mixed in during the lithium extraction process from lithium ore. Those skilled in the art can make adaptive selections and adjustments according to actual needs.

[0014] Furthermore, the composition of the lithium smelting slag is not unique; the composition of different lithium ore solid wastes can be adaptively selected and adjusted according to actual needs.

[0015] For example, the spodumene smelting slag has the following composition by weight percentage: SiO2 45%~55%, Al2O3 15%~25%, SO3 5%~15%, CaO 10%~25%, Na2O 0.5%~3.0%, K2O 3%~8%, Fe2O3 2%~4%.

[0016] For example, the lepidolite smelting slag has the following composition by weight percentage: SiO2 25%~40%, Al2O3 10%~22%, SO3 5%~15%, CaO 15%~25%, Na2O 0.5%~3%, K2O 2%~6%, Fe2O3 1%~5%.

[0017] Preferably, by mass fraction, the mixture comprises 40% to 85% lithium smelting slag, 7% to 25% solid waste and 1% to 15% auxiliary materials.

[0018] For example, the mass fraction of the lithium smelting slag can be 40%, 43%, 45%, 48%, 50%, 53%, 55%, 58%, 60%, 63%, 65%, 68%, 70%, 73%, 75%, 78%, 80%, 83%, or 85%, etc.; the mass fraction of the solid waste can be 7%, 8%, 9%, 10%, 13%, 15%, 18%, 20%, 23%, or 25%, etc.; and the mass fraction of the auxiliary materials can be 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, or 15%, etc.

[0019] It is understood that the shell strengthening method provided by the present invention is applicable to the preparation process of various lithium slag-based non-burning lightweight aggregates, and the corresponding raw materials are applicable to any conventional lithium slag-based non-burning lightweight aggregate raw materials and corresponding proportions, provided that the overall technical concept of the present invention is not violated.

[0020] Preferably, the solid waste in step S1 includes fly ash.

[0021] Preferably, the auxiliary materials in step S1 include a binder and / or an activator, wherein the binder includes cement and the activator includes calcium oxide.

[0022] Preferably, the initial granulation rotation speed in step S2 is 25 r / min to 35 r / min, such as 25 r / min, 26 r / min, 27 r / min, 28 r / min, 29 r / min, 30 r / min, 31 r / min, 32 r / min, 33 r / min, 34 r / min or 35 r / min, etc.

[0023] Preferably, the moisture content of the raw material balls in step S2 is 15% to 23%, such as 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, or 23%.

[0024] The moisture content of the raw material balls obtained in step S2 of this invention refers to the mass percentage of water in the corresponding raw material balls. This mass percentage plays a crucial role in the subsequent round pot granulation process. When the moisture content is between 15% and 23%, the surface of the granulated raw material balls is in a suitable state, i.e., neither excessively wet nor excessively dry. When the moisture content is less than 15%, the raw material balls are excessively dry, resulting in insufficient hydration reaction. Furthermore, the raw material balls at this point are relatively loose and prone to cracking during shell strengthening. When the moisture content is greater than 23%, the raw material balls become excessively wet, leading to adhesion between them. This prevents effective rolling during strengthening and may also cause them to slide on the round pot wall, resulting in shell strengthening failure.

[0025] Preferably, the diameter of the raw material ball in step S2 is 5mm to 20mm, such as 5mm, 8mm, 10mm, 13mm, 15mm, 18mm or 20mm.

[0026] It is worth noting that, in this invention, the raw material balls obtained in step S2 are left to stand for less than 10 hours.

[0027] Preferably, the radius R of the granulation container in the circular pot granulation in step S3 and the maximum width W of the granulation container satisfy the following: 0.8≤R / W≤1.2, for example, 0.8, 0.85, 0.9, 0.95, 1, 1.05, 1.1, 1.15 or 1.2, etc.; and the central angle α corresponding to the arc is 110°~130°, for example, 110°, 115°, 120°, 125° or 130°, etc.

[0028] In step S3, the granulation container of the round pot granulation is a container type with a certain degree of curvature. By adjusting the relationship between the radius R of the curvature and the maximum width W of the granulation container and / or the numerical range of the central angle corresponding to the curvature, the efficiency of shell strengthening is further improved. When the ratio of R to W exceeds this range, the raw material balls will exhibit projectile motion, thus failing to achieve effective strengthening.

[0029] Meanwhile, it is understood that the granulation equipment used in the round pot granulation of the present invention can be directly purchased from commercial sources. It can be adapted to the corresponding feature and requirement limitations without the need for self-construction; or it can be self-constructed using conventional methods to achieve the corresponding technical objectives.

[0030] Preferably, in step S3, the total volume of the raw material balls to be granulated in the granulation container of the round pot granulator is less than 30% of the volume of the granulation container of the round pot granulator. For example, if the volume of the granulation container is V, the total volume of the raw material balls to be granulated in the granulation container of the round pot granulator can be 5%V, 15%V, 20%V, 25%V, 28%V or 2%V, etc.

[0031] Preferably, the rotation speed of the round pot granulation in step S3 is 20 r / min to 60 r / min, such as 20 r / min, 25 r / min, 30 r / min, 35 r / min, 40 r / min, 45 r / min, 50 r / min, 55 r / min or 60 r / min.

[0032] In the circular pot granulation process of step S3 of this invention, the rotation speed of the circular pot granulation is controlled between 20 r / min and 60 r / min. Within this range, a faster rotation speed results in better shell strengthening. Below this speed, insufficient mechanical force prevents effective rolling between the raw material pellets. Above 60 r / min, the raw material pellets tend to undergo projectile motion within the circular pot. In summary, both excessively low and excessively high rotation speeds will lead to insufficient or failed strengthening of the raw material pellets.

[0033] Preferably, the granulation time of the round pot granulation in step S3 is 15 min to 120 min, more preferably 80 min to 120 min, such as 15 min, 20 min, 30 min, 40 min, 50 min, 60 min, 70 min, 80 min, 85 min, 90 min, 95 min, 100 min, 105 min, 110 min, 115 min or 120 min, etc.

[0034] In the round pot granulation process of step S3, the corresponding granulation time has an important impact on shell strengthening. A relatively long granulation time of 80min~120min can better achieve shell strengthening and further improve the surface density of lithium slag-based non-burning lightweight aggregate while ensuring the same bulk density.

[0035] Preferably, the curing method described in step S4 includes steam curing.

[0036] Preferably, the temperature for steam curing is 60℃~90℃, such as 60℃, 65℃, 70℃, 75℃, 80℃, 85℃ or 90℃.

[0037] Preferably, the humidity for steam curing is 90% to 99%, such as 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%.

[0038] Preferably, the steam curing time is 4h to 8h, such as 4h, 5h, 6h, 7h or 8h.

[0039] In a second aspect, the present invention also provides a shell-strengthened lithium slag-based non-burning lightweight aggregate, wherein the shell-strengthened lithium slag-based non-burning lightweight aggregate is prepared by the shell-strengthening method described in the first aspect.

[0040] The numerical range described in this invention includes not only the point values ​​listed above, but also any point values ​​within the numerical ranges not listed above. Due to space limitations and for the sake of brevity, this invention will not exhaustively list all the specific point values ​​included in the range.

[0041] Compared with the prior art, the present invention has the following beneficial effects:

[0042] In the shell strengthening method provided by the present invention, after obtaining the initial raw material balls, the shell of the lithium slag-based non-burning lightweight aggregate is further subjected to round pot granulation treatment. A special granulation method is used to mechanically strengthen the shell of the lithium slag-based non-burning lightweight aggregate. While ensuring the same bulk density, the density of the surface of the lithium slag-based non-burning lightweight aggregate is increased, thereby improving its compressive strength and reducing its water absorption rate. Attached Figure Description

[0043] Figure 1 Comparative figures show the physical comparison of lithium slag-based lightweight aggregates prepared in Example 1 (red circle) and Comparative Example 1 (blue circle).

[0044] Figure 2 This is a SEM image of the structure of the lithium slag-based lightweight aggregate prepared in Example 1, from the inside out.

[0045] Figure 3 for Figure 1 SEM image of the surface of the lithium slag-based lightweight aggregate prepared in Comparative Example 1.

[0046] Figure 4 for Figure 1 Surface SEM image of the lithium slag-based lightweight aggregate prepared in Example 1. Detailed Implementation

[0047] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0048] The "range" disclosed in this invention can be defined in the form of a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, which define the boundaries of the specific range. This type of range definition can include or exclude endpoints; any endpoint can be independently included or excluded, and they can be arbitrarily combined, meaning any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60~120 and 80~110 are listed for specific parameters, it is understood that ranges of 60~110 and 80~120 are also expected. Furthermore, if minimum range values ​​1 and 2 are listed, and maximum range values ​​3, 4, and 5 are also listed, then the following ranges are all expected: 1~3, 1~4, 1~5, 2~3, 2~4, and 2~5. In this invention, unless otherwise stated, the numerical range "a~b" represents a shortened representation of any combination of real numbers between a and b, where a and b are real numbers. For example, the numerical range "0~5" indicates that all real numbers between "0" and "5" have been listed in this article; "0~5" is simply a shortened representation of these numerical combinations. Furthermore, when a parameter is described as an integer ≥2, it is equivalent to listing integers such as 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc. For instance, when a parameter is described as an integer selected from "2~10", it is equivalent to listing the integers 2, 3, 4, 5, 6, 7, 8, 9, and 10.

[0049] In this invention, "a combination of at least two" refers to a quantity greater than or equal to two, unless otherwise specified. For example, "any combination of one or at least two" means one or more or more items. It can be understood that when referring to "a combination of at least two," it refers to any suitable combination of multiple items, that is, a combination of "at least two" items carried out in a manner that does not conflict with and enables the implementation of this invention.

[0050] Unless otherwise specified, all embodiments and optional embodiments of the present invention can be combined with each other to form new technical solutions.

[0051] The term "embodiment" as used in this invention means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment or implementation of the invention. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described in this invention can be combined with other embodiments.

[0052] Those skilled in the art will understand that the order in which the steps are written in the methods of the various embodiments does not imply a strict execution order. The detailed execution order of each step should be determined by its function and possible internal logic. Unless otherwise specified, all steps of the present invention may be performed sequentially or randomly, but are preferably performed sequentially. For example, if the method includes steps (a) and (b), it means that the method may include steps (a) and (b) performed sequentially, or it may include steps (b) and (a) performed sequentially. For example, the method may also include step (c), meaning that step (c) can be added to the method in any order. For example, the method may include steps (a), (b), and (c), or it may include steps (a), (c), and (b), or it may include steps (c), (a), and (b), etc.

[0053] In this invention, open-ended technical features or solutions described using terms such as "comprising" do not exclude additional members beyond those listed unless otherwise specified. They can be considered as providing both closed-ended features or solutions comprised of the listed members and open-ended features or solutions that include additional members beyond the listed members. For example, A includes a1, a2, and a3. Unless otherwise specified, it may also include other members or exclude additional members. This can be considered as providing both technical features or solutions where "A is composed of a1, a2, and a3" or "A is selected from a1, a2, and a3," and technical features or solutions where "A includes not only a1, a2, and a3, but also other members."

[0054] In this invention, unless otherwise specified, the features or solutions corresponding to "and / or" include any one of two or more of the related listed items, as well as any and all combinations of the related listed items. These arbitrary and all combinations include any two related listed items, any more related listed items, or a combination of all related listed items. For example, "A and / or B" represents a group consisting of A, B, and "a combination of A and B". "Containing A and / or B" can mean "containing A, containing B, and containing A and B", or "containing A, containing B, or containing A and B", and can be appropriately understood according to the context.

[0055] In this invention, the terms "first aspect," "second aspect," "third aspect," "fourth aspect," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or quantity, nor should they be construed as implicitly indicating the importance or quantity of the indicated technical features. Moreover, "first," "second," "third," "fourth," etc., serve only as a non-exhaustive enumeration and should be understood not to constitute a closed limitation on the quantity.

[0056] In this invention, "optional" means that something is optional, that is, it refers to any one of the two parallel solutions of "having" or "not having". If there are multiple "optional" options in a technical solution, unless otherwise specified, and there are no contradictions or mutual constraints, then each "optional" option is independent.

[0057] In this invention, "room temperature" generally refers to 4℃~35℃, and can refer to 20℃±5℃. In some embodiments of this invention, room temperature refers to 20℃~30℃.

[0058] In one specific embodiment, the present invention provides the specific composition and weight percentage of the corresponding components of spodumene smelting slag and lepidolite smelting slag, as shown in Table 1.

[0059] Table 1

[0060]

[0061] The lithium smelting slag in the following examples and comparative examples all uses the materials provided in the specific embodiments described above.

[0062] Example 1

[0063] This embodiment provides a shell strengthening method for lithium slag-based non-burning lightweight aggregates, the shell strengthening method comprising the following steps:

[0064] First, provide the corresponding raw materials for preparation: spodumene smelting slag, lepidolite smelting slag, fly ash, ordinary 425 silicate cement, and activator calcium oxide in a mass ratio of 50:35:7:6:2.

[0065] S1: Lithium smelting slag and solid waste fly ash are mixed in proportion, and after crushing and mixing, a composite slag material is obtained. Cement and activator are added to the composite slag material, and the mixture is stirred for 50 minutes to obtain a mixed material.

[0066] S2: Place the mixture in a disc granulator and granulate by slowly adding water. The disc granulator rotates at 25 r / min and tilts at 50° to produce raw material balls with a diameter of 5~20 mm and a moisture content of 20%.

[0067] S3: The obtained raw material pellets are placed in a round pot granulator of the strengthening device (the cross-section of the round pot is arc-shaped, and its arc radius R and the maximum width W of the pot body satisfy R / W=1, and the central angle α corresponding to the arc is 120°) for round pot granulation treatment. The rotation speed is 60r / min, the strengthening time is 80min, and the total volume of the raw material pellets accounts for 25% of the capacity of the strengthening device. The shell of the lithium slag-based non-burning light aggregate is strengthened by mechanical force to obtain shell-strengthened raw material pellets.

[0068] S4: Place the raw material balls obtained in S3 into a curing box and steam-cur them at 80℃ and 95% humidity for 8 hours to obtain the finished lightweight aggregate.

[0069] Example 2

[0070] This embodiment provides a shell strengthening method for lithium slag-based non-burning lightweight aggregates, the shell strengthening method comprising the following steps:

[0071] First, provide the corresponding raw materials for preparation: spodumene smelting slag, lepidolite smelting slag, fly ash, ordinary 425 silicate cement, and activator calcium oxide in a mass ratio of 50:35:7:6:2.

[0072] S1: Lithium smelting slag and solid waste fly ash are mixed in proportion, and after crushing and mixing, a composite slag material is obtained. Cement and activator are added to the composite slag material, and the mixture is stirred for 50 minutes to obtain a mixed material.

[0073] S2: Place the mixture in a disc granulator and granulate by slowly adding water. The disc granulator rotates at 35 r / min and tilts at 50° to produce raw material balls with a diameter of 5~20 mm and a moisture content of 20%.

[0074] S3: The obtained raw material pellets are placed in a round pot granulator of the strengthening device (the cross-section of the round pot is arc-shaped, and its arc radius R and the maximum width W of the pot body satisfy R / W=1, and the central angle α corresponding to the arc is 110°) for round pot granulation treatment. The rotation speed is 30r / min, the strengthening time is 80min, and the total volume of the raw material pellets accounts for 25% of the capacity of the strengthening device. The shell of the lithium slag-based non-burning light aggregate is strengthened by mechanical force to obtain shell-strengthened raw material pellets.

[0075] S4: Place the raw material balls obtained in S3 into a curing box and steam-cur them at 90℃ and 90% humidity for 4 hours to obtain the finished lightweight aggregate.

[0076] Example 3

[0077] This embodiment provides a shell strengthening method for lithium slag-based non-burning lightweight aggregates, the shell strengthening method comprising the following steps:

[0078] First, provide the corresponding raw materials for preparation: spodumene smelting slag, lepidolite smelting slag, fly ash, ordinary 425 silicate cement, and activator calcium oxide in a mass ratio of 50:35:7:6:2.

[0079] S1: Lithium smelting slag and solid waste fly ash are mixed in a certain proportion, and after crushing and mixing, a composite slag material is obtained. Cement and activator are added to the composite slag material and mixed and stirred for 60 minutes to obtain a mixture.

[0080] S2: Place the mixture in a disc granulator and granulate by slowly adding water. The disc granulator rotates at 30 r / min and tilts at 50° to produce raw material balls with a diameter of 5~20 mm and a moisture content of 20%.

[0081] S3: The obtained raw material pellets are placed in a round pot granulator of the strengthening device (the cross-section of the round pot is arc-shaped, and its arc radius R and the maximum width W of the pot body satisfy R / W=0.8, and the central angle α corresponding to the arc is 130°) for round pot granulation treatment. The rotation speed is 60r / min, the strengthening time is 100min, and the total volume of the raw material pellets accounts for 25% of the capacity of the strengthening device. The shell of the lithium slag-based non-burning light aggregate is strengthened by mechanical force to obtain shell-strengthened raw material pellets.

[0082] S4: Place the raw material balls obtained in S3 into a curing box and steam-cur them at 80℃ and 95% humidity for 8 hours to obtain the finished lightweight aggregate.

[0083] Example 4

[0084] The difference between this embodiment and embodiment 1 is that the moisture content of the raw material balls in step S2 of this embodiment is 15%.

[0085] All other conditions remain the same as in Example 1.

[0086] Example 5

[0087] The difference between this embodiment and embodiment 1 is that the moisture content of the raw material balls in step S2 of this embodiment is 23%.

[0088] All other conditions remain the same as in Example 1.

[0089] Example 6

[0090] The difference between this embodiment and embodiment 1 is that the moisture content of the raw material balls in step S2 of this embodiment is 12%.

[0091] All other conditions remain the same as in Example 1.

[0092] Example 7

[0093] The difference between this embodiment and embodiment 1 is that the moisture content of the raw material balls in step S2 of this embodiment is 25%.

[0094] All other conditions remain the same as in Example 1.

[0095] Example 8

[0096] The difference between this embodiment and embodiment 1 is that in step S3 of this embodiment, the total volume of the raw material balls accounts for 40% of the capacity of the strengthening device.

[0097] All other conditions remained the same as in Example 1.

[0098] Example 9

[0099] The difference between this embodiment and embodiment 1 is that in step S3 of this embodiment, the radius of the arc R and the maximum width W of the pot body satisfy R / W=0.5.

[0100] All other conditions remain the same as in Example 1.

[0101] Example 10

[0102] The difference between this embodiment and embodiment 1 is that in step D3 of this embodiment, the radius R of the arc and the maximum width W of the pot body satisfy R / W=1.5.

[0103] All other conditions remain the same as in Example 1.

[0104] Example 11

[0105] The difference between this embodiment and embodiment 1 is that the rotation speed of the round pot granulation in step S3 of this embodiment is 20 r / min.

[0106] All other conditions remain the same as in Example 1.

[0107] Example 12

[0108] The difference between this embodiment and embodiment 1 is that the rotation speed of the round pot granulation in step S3 of this embodiment is 10 r / min.

[0109] All other conditions remain the same as in Example 1.

[0110] Example 13

[0111] The difference between this embodiment and embodiment 1 is that the rotation speed of the round pot granulation in step S3 of this embodiment is 70 r / min.

[0112] All other conditions remain the same as in Example 1.

[0113] Example 14

[0114] The difference between this embodiment and Embodiment 1 is that the time for granulation in the round pot in step S3 of this embodiment is 120 minutes.

[0115] All other conditions remain the same as in Example 1.

[0116] Example 15

[0117] The difference between this embodiment and Embodiment 1 is that the time for granulation in the round pot in step S3 of this embodiment is 15 minutes.

[0118] All other conditions remain the same as in Example 1.

[0119] Example 16

[0120] The difference between this embodiment and Embodiment 1 is that the time for granulation in the round pot in step S3 of this embodiment is 10 minutes.

[0121] All other conditions remain the same as in Example 1.

[0122] Example 17

[0123] The difference between this embodiment and Embodiment 1 is that the time for granulation in the round pot in step S3 of this embodiment is 130 minutes.

[0124] All other conditions remain the same as in Example 1.

[0125] Comparative Example 1

[0126] The difference between this comparative example and Example 1 is that this comparative example does not perform step S3, but directly performs the curing treatment of the raw material balls from step S2 in step S4.

[0127] All other conditions remain the same as in Example 1.

[0128] Figure 1 The images show a comparison of the physical samples of lithium slag-based lightweight aggregates prepared in Example 1 (red circle) and Comparative Example 1 (blue circle).

[0129] Figure 2 The SEM image of the lithium slag-based lightweight aggregate prepared in Example 1 is shown from the inside out.

[0130] Figure 3 It shows Figure 1 SEM image of the surface of the lithium slag-based lightweight aggregate prepared in Comparative Example 1.

[0131] Figure 4 It shows Figure 1 Surface SEM image of the lithium slag-based lightweight aggregate prepared in Example 1.

[0132] from Figure 1 As can be seen from the macroscopic diagram, the surface color of the reinforced lightweight aggregate changes significantly, and its smoothness and density increase markedly.

[0133] from Figure 2 As can be seen, lightweight aggregate exhibits an inner and outer shell structure, with a dense outer shell and a porous inner shell. This structure is beneficial in ensuring higher strength and lower water absorption without increasing bulk density.

[0134] Figure 3 and Figure 4 The SEM images clearly show the increased density of the reinforced lightweight aggregate.

[0135] The lithium slag-based non-fired lightweight aggregates prepared in Examples 1-17 and Comparative Example 1 were tested for bulk density, compressive strength and 1-hour water absorption rate according to GB / T 17431.2-2010. The test results are shown in Table 2.

[0136] Table 2

[0137]

[0138] From the data analysis in Table 2, we can conclude that:

[0139] Data analysis of Examples 1 and 4-7 shows that when the moisture content of the raw material balls is not within the range of 15% to 23%, the effect of improving the compressive strength of the cylinder is relatively low and the decrease in water absorption rate is also relatively low.

[0140] Data analysis of Examples 1 and 8 shows that the volume ratio of the raw material balls to be granulated in the granulation container of the circular pot granulation affects the enhanced granulation effect. If the ratio is too large, exceeding 30%, it will lead to uneven granulation during rolling, poor shell reinforcement effect, and affect bulk density, cylinder compressive strength and water absorption rate.

[0141] Data analysis of Examples 1, 9, and 10 shows that by controlling the relationship between the arc radius R and the maximum width W of the granulation container and / or the numerical range of the corresponding central angle of the arc, 0.8≤R / W≤1.2, the efficiency of shell strengthening is further improved, particle packing is increased, the cylinder compressive strength is improved, and the water absorption rate is reduced.

[0142] Data analysis of Examples 1 and 11-13 shows that a rotation speed of 20 r / min to 60 r / min during the round pot granulation process ensures the effective rolling of the raw material balls while preventing them from forming projectile motion, thus more effectively enhancing the shell strengthening effect.

[0143] Data analysis of Examples 1 and 14-17 shows that the corresponding granulation time has a significant impact on shell strengthening. A relatively long granulation time of 80 min to 120 min is needed to better achieve shell strengthening and further improve the surface density of lithium slag-based non-burning lightweight aggregate while ensuring the same bulk density.

[0144] Data analysis of Example 1 and Comparative Example 1 shows that the initial granulation followed by round pot granulation in this invention strengthens the outer shell of the lithium slag-based non-burning lightweight aggregate through mechanical force. While maintaining the same bulk density, it significantly improves the surface density of the lithium slag-based non-burning lightweight aggregate, thereby increasing its compressive strength and reducing its water absorption rate.

[0145] The above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A method for shell reinforcement of lithium slag-based non-fired lightweight aggregate, characterized in that, The shell strengthening method includes the following steps: S1. Mix lithium smelting slag, solid waste and auxiliary materials to obtain a mixture; S2. Perform initial granulation treatment on the mixture to obtain raw material pellets; S3. The raw material balls are subjected to round pot granulation to obtain shell-reinforced raw material balls; the radius R of the round pot granulation container and the maximum width W of the granulation container satisfy: 0.8≤R / W≤1.2; and the central angle α corresponding to the round pot is 110°~130°. S4. The shell-reinforced raw material balls are cured to obtain the lithium slag-based non-fired lightweight aggregate.

2. The shell strengthening method according to claim 1, characterized in that, The mixture comprises, by mass fraction, 40% to 85% lithium smelting slag, 7% to 25% solid waste and 1% to 15% auxiliary materials.

3. The shell strengthening method according to claim 1 or 2, characterized in that, The solid waste mentioned in step S1 includes fly ash; And / or, the auxiliary materials in step S1 include a binder and / or an activator, wherein the binder includes cement and the activator includes calcium oxide; And / or, the initial granulation rotation speed in step S2 is 25 r / min to 35 r / min.

4. The shell strengthening method according to claim 1, characterized in that, The moisture content of the raw material balls in step S2 is 15%~23%, and the diameter of the raw material balls in step S2 is 5mm~20mm.

5. The shell strengthening method according to claim 1, characterized in that, In step S3, the total volume of the raw material pellets to be granulated in the granulation container of the round pot granulator is less than 30% of the volume of the granulation container of the round pot granulator.

6. The shell strengthening method according to claim 1, characterized in that, The rotation speed of the round pot granulation in step S3 is 20 r / min to 60 r / min; And / or, the granulation time of the round pot granulation in step S3 is 15 min to 120 min.

7. The shell strengthening method according to claim 6, characterized in that, The granulation time for the round pot granulation in step S3 is 80 min to 120 min.

8. The shell strengthening method according to claim 1, characterized in that, The curing method described in step S4 includes steam curing, with a steam curing temperature of 60℃~90℃, a steam curing humidity of 90%~99%, and a steam curing time of 4h~8h.

9. A shell-reinforced lithium slag-based non-fired lightweight aggregate, characterized in that, The shell-strengthened lithium slag-based non-burning lightweight aggregate is prepared by the shell-strengthening method as described in any one of claims 1-8.

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