CN-121554252-B - Shell reinforcing method of lithium slag-based baking-free lightweight aggregate and lithium slag-based baking-free lightweight aggregate after shell reinforcing

Abstract

The invention discloses a shell reinforcing method of a lithium slag-based baking-free lightweight aggregate and the lithium slag-based baking-free lightweight aggregate after shell reinforcement. The shell reinforcing method comprises the following steps of S1, mixing lithium smelting slag, solid waste and auxiliary materials to obtain a mixed material, S2, carrying out initial granulation treatment on the mixed material to obtain raw material balls, S3, carrying out round pot granulation treatment on the raw material balls to obtain shell reinforcing raw material balls, and S4, carrying out maintenance treatment on the shell reinforcing raw material balls to obtain the lithium slag-based baking-free lightweight aggregate. According to the shell reinforcing method provided by the invention, after raw material balls are obtained through initial granulation, the round pan granulation treatment is carried out, and the special granulation mode is utilized to mechanically reinforce the shell of the lithium slag-based baking-free lightweight aggregate, so that the surface compactness degree of the lithium slag-based baking-free lightweight aggregate is improved under the condition of ensuring the same stacking density, the barrel pressure strength of the lithium slag-based baking-free lightweight aggregate is improved, and the water absorption rate of the lithium slag-based baking-free lightweight aggregate is reduced.

Inventors

• LI GUOBIAO
• QI TAO
• WANG DONG
• Zou Jiezhong
• ZHANG ZHIHAN
• CHENG SHUPING
• LIU YANHONG
• ZENG YANXI
• DAI SHENGXIAN

Assignees

• 中国科学院赣江创新研究院

Dates

Publication Date

20260508

Application Date

20260122

Claims (9)

1. 1. The shell strengthening method of the lithium slag-based baking-free lightweight aggregate is characterized by comprising the following steps of: s1, mixing lithium smelting slag, solid waste and auxiliary materials to obtain a mixed material; S2, carrying out initial granulation treatment on the mixed material to obtain raw material balls; S3, carrying out round pan granulation on the raw material balls to obtain shell-reinforced raw material balls, wherein the radius R of an arc of a granulating container for round pan granulation and the maximum width W of the granulating container in the step S3 are 0.8-1.2, and the corresponding central angle alpha of the arc is 110-130 degrees; and S4, curing the shell reinforced raw material balls to obtain the lithium slag-based baking-free lightweight aggregate.
2. 2. The shell strengthening method according to claim 1, wherein the mixed material comprises, by mass, 40% -85% of lithium smelting slag, 7% -25% of solid waste and 1% -15% of auxiliary materials.
3. 3. The method for reinforcing a shell according to claim 1 or 2, wherein the solid waste in step S1 comprises fly ash; And/or, the auxiliary materials in the step S1 comprise a binder and/or an exciting agent, wherein the binder comprises cement, and the exciting agent comprises calcium oxide; and/or the rotating speed of the initial granulation in the step S2 is 25-35 r/min.
4. 4. The method for reinforcing a shell layer according to claim 1, wherein the water content of the raw material balls in the step S2 is 15% -23%, and the diameter of the raw material balls in the step S2 is 5 mm-20 mm.
5. 5. The method for reinforcing a shell according to claim 1, wherein in step S3, the total volume of raw pellets to be granulated in the granulation vessel for round pan granulation is <30% of the volume of the granulation vessel for round pan granulation.
6. 6. The shell strengthening method according to claim 1, wherein the rotation speed of the round pan granulation in the step S3 is 20r/min to 60r/min; And/or, granulating the materials in the step S3, wherein the granulating time of the round pan granulating is 15-120 min.
7. 7. The method of reinforcing a shell according to claim 6, wherein the granulating time of the round pan granulating in the step S3 is 80-120 min.
8. 8. The method for reinforcing a shell according to claim 1, wherein the curing method in step S4 includes steam curing, the temperature of the steam curing is 60 ℃ to 90 ℃, the humidity of the steam curing is 90% to 99%, and the time of the steam curing is 4 hours to 8 hours.
9. 9. A shell-reinforced lithium slag-based baking-free lightweight aggregate, characterized in that the shell-reinforced lithium slag-based baking-free lightweight aggregate is prepared by the shell-reinforcing method according to any one of claims 1 to 8.

Description

Shell reinforcing method of lithium slag-based baking-free lightweight aggregate and lithium slag-based baking-free lightweight aggregate after shell reinforcing Technical Field The invention belongs to the technical field of solid waste recycling and environment-friendly materials, and relates to a shell reinforcing method of lithium slag-based baking-free lightweight aggregate and the lithium slag-based baking-free lightweight aggregate after shell reinforcement. Background With the rapid development of new energy, the demand of lithium salt products is also increased. Lithium slag is a solid waste produced during the lithium extraction of lithium ores. The lightweight aggregate is used as a core lightweight component of concrete, and the environment-friendly preparation technology of the lightweight aggregate is of great concern. Therefore, the lithium slag-based preparation of the lightweight aggregate becomes a mainstream trend, however, the traditional sintering lightweight aggregate has the defects of high energy consumption (the roasting temperature is more than 1000 ℃), large carbon emission and the like, and the baking-free lightweight aggregate can reduce the energy consumption, but generally has the defects of insufficient shell strength, surface powder removal, high water absorption and the like. Therefore, how to improve the pressure intensity of the lithium slag based baking-free lightweight aggregate and reduce the water absorption rate of the lithium slag based baking-free lightweight aggregate is of great significance to the high-efficiency application of the lithium slag based baking-free lightweight aggregate. The baking-free lightweight aggregate has the advantages of light weight, high strength and excellent heat preservation and insulation properties, and is widely applied to the fields of building aggregate, heat preservation and insulation materials, ecological greening, toilet backfill and the like. At present, a baking-free lightweight aggregate preparation process taking lithium slag as a main raw material exists. CN117185690A discloses a lithium slag-based baking-free light ceramsite, a preparation method and application thereof, wherein spodumene lithium extraction residues are used as basic raw materials, the mixture ratio is 60-80 parts of lithium slag, 10-20 parts of cement, 8-15 parts of quicklime, 3-8 parts of alkali-activated agent, 1-6 parts of foaming agent and 12-20 parts of water. The pressure intensity of the obtained lithium slag based baking-free lightweight aggregate is 9.41MPa at the highest, the water absorption is 11.4%, and a large amount of cement and quicklime are required to be added to form a main gelling system. However, the water absorption rate is too high, which affects the later use effect. CN118908610A is modified natural lightweight aggregate, and is prepared by mixing shell phosphogypsum, fly ash, slag powder and quicklime, and by adopting an inner shell mode, the stacking density of ceramsite is reduced, and the barrel pressure intensity of the ceramsite is improved. However, the inside of the composite material consists of modified natural lightweight aggregate, the component difference exists between the core-shell structures, and the defects of core-shell separation, strength reduction and the like are easy to occur. Therefore, the densification degree of the lithium slag-based baking-free lightweight aggregate is improved, the bulk density of the lithium slag-based baking-free lightweight aggregate is not influenced, and the lithium slag-based baking-free lightweight aggregate is a technical subject to be explored. Disclosure of Invention Aiming at the defects existing in the prior art, the invention aims to provide a shell reinforcing method of lithium slag based baking-free lightweight aggregate and the lithium slag based baking-free lightweight aggregate after shell reinforcement. According to the shell reinforcing method provided by the invention, after raw material balls are obtained through initial granulation, the round pan granulation treatment is carried out, and the special granulation mode is utilized to mechanically reinforce the shell of the lithium slag-based baking-free lightweight aggregate, so that the surface compactness degree of the lithium slag-based baking-free lightweight aggregate is improved under the condition of ensuring the same stacking density, the barrel pressure strength of the lithium slag-based baking-free lightweight aggregate is improved, and the water absorption rate of the lithium slag-based baking-free lightweight aggregate is reduced. In order to achieve the aim of the invention, the invention adopts the following technical scheme: In a first aspect, the invention provides a shell reinforcing method of lithium slag based baking-free lightweight aggregate, which comprises the following steps: s1, mixing lithium smelting slag, solid waste and auxiliary materials to obtain a mixed material; S2, carrying out