CN112430066A

CN112430066A - Light high-strength ceramsite and preparation method and application thereof

Info

Publication number: CN112430066A
Application number: CN201910790889.0A
Authority: CN
Inventors: 张红玲; 宋春光; 裴丽丽; 董玉明; 刘宏辉; 徐红彬
Original assignee: Institute of Process Engineering of CAS
Current assignee: Institute of Process Engineering of CAS
Priority date: 2019-08-26
Filing date: 2019-08-26
Publication date: 2021-03-02

Abstract

The invention relates to a light high-strength ceramsite and a preparation method and application thereof. The preparation method of the light high-strength ceramsite comprises the following steps: (1) mixing the stone coal sodium salt roasting vanadium extraction tailings and an aluminum-containing auxiliary material to obtain a mixed material; (2) and (2) granulating and roasting the mixed material obtained in the step (1) to obtain the light high-strength ceramsite. The invention takes stone coal sodium salt roasting vanadium extraction tailings as raw materials, adds waste such as fly ash, red mud, aluminum ash and the like as auxiliary materials, and realizes effective fixation of alkali metal in the stone coal sodium salt roasting vanadium extraction tailings and preparation of light high-strength ceramsite with low bulk density, high barrel pressure strength and low water absorption rate by controlling the raw material and auxiliary material proportion and roasting process parameters through the steps of mixing, pelletizing, drying, roasting, cooling and the like, thereby realizing harmless and recycling of various industrial wastes.

Description

Light high-strength ceramsite and preparation method and application thereof

Technical Field

The invention belongs to the technical field of solid waste resource utilization, and particularly relates to light high-strength ceramsite and a preparation method and application thereof.

Background

The development of industrial and mining enterprises and the acceleration of urbanization progress promote social progress and improvement of human living standard, but a large amount of pollutants generated in the production and living process also cause the aggravation of environmental problems. Researchers at home and abroad spend a large amount of manpower and material resources to carry out treatment research on the environment, and the aims of further improving the life quality of people and reducing the harm of pollutants to the environment are fulfilled. However, the current research mainly focuses on the aspects of atmospheric air and water treatment, and the final state of the solid waste is not paid enough attention to people, so that a series of environmental problems are caused, not only is the serious environmental pollution caused, but also the development of social economy is restrained.

The stone coal has the characteristics of rich vanadium reserves, wide regional distribution and the like, along with the development of the stone coal vanadium extraction process and the application of vanadium in the high-tech field, the stone coal vanadium metallurgy industry has become an important industry in China, and the extraction of vanadium from the stone coal also becomes an important way for obtaining vanadium resources in China. However, the characteristic of low vanadium grade (0.13-1.2%) of stone coal in China generally exists, so that a large amount of waste stone is generated in the mining stage, a large amount of leaching slag is generated in the production process, the leaching slag is generally treated by backfilling mine pits at present, but the solid waste slag does not have a proper utilization means at present, is simply treated by mainly adopting a tailing pond stacking mode, and can pollute the surrounding environment in the stacking process, so that the resource utilization of the stone coal vanadium-extracted solid waste is imperative.

At present, most of the traditional ceramsite production is prepared by sintering clay and shale as main raw materials at high temperature, a large amount of natural resources are consumed, cultivated land and ecological environment are damaged, the principle of sustainable development is not met, and reduction, recycling and harmlessness of industrial solid waste can be realized by producing the ceramsite by using the industrial solid waste as the raw material, so that the research hotspot is realized.

CN103539480A discloses a method for preparing high-strength coal gangue ceramsite, which takes spontaneous combustion coal gangue and coal slime as main raw materials, and then adds fly ash, foaming agent, auxiliary agent and the like to prepare the high-strength coal gangue ceramsite, wherein the cylinder pressure strength can reach 8.28MPa, and the corresponding bulk density is 1096kg/m³The bulk density is still high. CN201610826984.8 discloses a method for preparing light high-strength fly ash ceramsite, which comprises the steps of preparing the light high-strength fly ash ceramsite by fly ash, pore-forming agent, fluxing agent, binding agent, reinforcing agent and the like, wherein the average water absorption of the prepared ceramsite is higher than 20%, and the water absorption is higher. CN104261802B discloses a high-strength ceramsite containing sludge and fly ash and a preparation method thereof, wherein the method takes sludge and fly ash as main raw materials, an additive is added to prepare the high-strength ceramsite containing fly ash, and the bulk density of the ceramsite is 650kg/m³The cylinder pressure strength is 3-6.3MPa, and the cylinder pressure strength is still lower.

However, at present, there are few reports of firing ceramsite by using stone coal sodium salt roasting vanadium extraction tailings, and the prior art cannot solve the problem of fixing alkali metal when preparing ceramsite by using stone coal sodium salt vanadium extraction tailings with high alkali metal content as a main raw material.

Disclosure of Invention

Aiming at the defects of the prior art, the invention aims to provide light-weight high-strength ceramsite and a preparation method and application thereof. According to the invention, the stone coal sodium salt roasting vanadium extraction tailings are used as a raw material, an aluminum-containing auxiliary material is added, and the processes of mixing, granulating, roasting and the like are carried out, so that the alkali metal in the stone coal sodium salt roasting vanadium extraction tailings is effectively fixed, the light high-strength ceramsite with low bulk density, high cylinder pressure strength and low water absorption rate is prepared, and the harmlessness and recycling of various industrial wastes are realized.

The lightweight high-strength ceramsite is prepared from the lightweight high-strength ceramsite with the bulk density of 500-1000 kg/m³(ii) a The barrel pressure strength is 5-25 MPa; corresponding cartridge at corresponding density levelThe compressive strength of the lightweight aggregate meets GB/T17431.1-2010 part 1 of the test method: 5.3 in the section of light aggregate, "Cylinder pressure Strength and Strength grade of light coarse aggregate" ceramsite specified in Table 4.

In order to achieve the purpose, the invention adopts the following technical scheme:

one of the purposes of the invention is to provide a preparation method of light high-strength ceramsite, which comprises the following steps:

(1) mixing the stone coal sodium salt roasting vanadium extraction tailings and an aluminum-containing auxiliary material to obtain a mixed material;

(2) and (2) granulating and roasting the mixed material obtained in the step (1) to obtain the light high-strength ceramsite.

According to the method, the stone coal sodium salt roasting vanadium extraction tailings are used as raw materials, the stone coal sodium salt roasting vanadium extraction tailings contain more valuable components, if the stone coal sodium salt roasting vanadium extraction tailings are not treated, resource waste can be caused, and environmental pollution can also be caused.

On one hand, the method takes the silicon dioxide and the aluminum oxide in the tailings of vanadium extraction by sodium salt roasting of the stone coal as framework components for utilization; on the other hand, by adopting the preparation method, alkali metals in the stone coal sodium salt roasting vanadium extraction tailings can participate in the reaction as fluxing components, so that the roasting temperature of the reaction can be reduced, and the sintering strength of the ceramsite is improved. By adopting the stone coal sodium salt roasting vanadium extraction tailings as a raw material, compared with clay or silicon-aluminum materials in the prior art, the roasting temperature can be reduced by 5-30%, so that the method not only realizes resource utilization of solid wastes, but also reduces energy consumption in the ceramsite preparation process and saves energy.

The stone coal sodium salt roasting vanadium extraction tailings contain more alkali metals, and if the stone coal sodium salt roasting vanadium extraction tailings are not treated, the environment pollution can be caused, the stone coal sodium salt roasting vanadium extraction tailings and aluminum-containing auxiliary materials are reacted, and through the regulation and control process, the alkali metal in the stone coal sodium salt roasting vanadium extraction tailings can be fixed, so that the ceramsite with higher strength can be obtained; meanwhile, partial sulfate and carbonate (or carbon) can exist in the stone coal sodium salt roasting vanadium extraction tailings, and the regulation and control process can decompose the sulfate and the carbonate to generate gas, so that the light high-strength ceramsite with a hard glaze layer on the surface and a large number of closed micropores in the interior can be obtained.

Preferably, the roasting of the step (2) is two-stage roasting, which comprises the following steps: the temperature is increased to a first temperature at a first temperature increase rate and then increased to a second temperature at a second temperature increase rate.

In the invention, the decomposition of gas-generating components, the reaction of alkali metals and the sintering and sintering expansion of material balls can be regulated by regulating the heating rate, the heat preservation temperature and the time of the two-stage roasting.

Preferably, the first temperature rise rate is 5-30 ℃/min, such as 6 ℃/min, 8 ℃/min, 10 ℃/min, 12 ℃/min, 15 ℃/min, 18 ℃/min, 20 ℃/min, 22 ℃/min, 25 ℃/min or 28 ℃/min, and the like.

The first temperature rise rate is too low, the gas production component loss is more, and the later expansion of the ceramsite is not facilitated; the first heating rate is too high, and the material balls are easy to crack.

Preferably, the first temperature is less than or equal to 550 ℃, preferably 300 to 550 ℃, such as 320 ℃, 350 ℃, 380 ℃, 400 ℃, 420 ℃, 450 ℃, 480 ℃, 500 ℃, 520 ℃, 530 ℃ or 540 ℃ and the like.

The first temperature is too low to effectively remove free water and bound water in the raw materials; the first temperature is too high, the loss of gas production components in the raw materials is more, and the later expansion of the ceramsite is not facilitated.

Preferably, the holding time at the first temperature is 1-50 min, such as 2min, 5min, 8min, 10min, 15min, 20min, 25min, 30min, 35min, 40min, 42min or 45 min.

Preferably, the second heating rate is 5-25 deg.C/min, such as 6 deg.C/min, 8 deg.C/min, 10 deg.C/min, 12 deg.C/min, 15 deg.C/min, 16 deg.C/min, 18 deg.C/min, 20 deg.C/min, 22 deg.C/min or 24 deg.C/min.

The second heating rate is too low, and excessive gas is released, so that the expansion of the material balls is not facilitated; and the second temperature rising rate is too high, so that gas is released rapidly, and the material balls are easy to crack.

Preferably, the second temperature is 1025 ℃ or more, preferably 1025 to 1300 ℃, such as 1030 ℃, 1050 ℃, 1080 ℃, 1100 ℃, 1120 ℃, 1150 ℃, 1180 ℃, 1200 ℃, 1250 ℃ or 1280 ℃ or the like.

The second temperature is too low, the sintering degree of the material balls is too low, and the bulk density and the water absorption are too high; and when the second temperature is too high, the pellets are easy to over-burn, and the pellets are melted and adhered.

Preferably, the holding time at the second temperature is 1-50 min, such as 2min, 5min, 8min, 10min, 15min, 20min, 25min, 30min, 35min, 40min, 42min or 45 min.

Preferably, the roasting further comprises a cooling process.

Preferably, the cooling is furnace cooling to room temperature.

The invention adopts a temperature reduction system of discharging the ceramsite after the ceramsite is cooled to room temperature along with the furnace, thereby avoiding the occurrence of fine cracks on the surface of the ceramsite caused by temperature shrinkage stress generated inside and on the surface of the ceramsite during rapid temperature reduction, and further improving the strength of the ceramsite.

Preferably, the granulation process of step (2) comprises: and mixing the mixed material, water and the binder, and granulating by using granulation equipment to obtain the raw material balls.

Preferably, the binder comprises any one of hydroxypropyl methylcellulose, polyvinyl alcohol, sodium silicate, soluble starch, xanthan gum and sesbania powder or a combination of at least two thereof.

The invention improves the raw material caking property, improves the balling rate and simultaneously improves the raw material ball strength by adding the caking agent with proper proportion and variety. The selected binder can effectively bind the stone coal sodium salt roasting vanadium extraction tailings and the aluminum-containing auxiliary materials to form pellets, and the selected organic binder can be decomposed in the roasting process, so that the reduction of the stacking density of the ceramsite is facilitated; the inorganic binder can play a role in fluxing.

Preferably, the binder is added in an amount of 0.01 to 3 wt% based on the mass of the pellet, for example, 0.02 wt%, 0.05 wt%, 0.1 wt%, 0.2 wt%, 0.5 wt%, 0.8 wt%, 1 wt%, 1.2 wt%, 1.5 wt%, 1.6 wt%, 1.8 wt%, 2 wt%, 2.2 wt%, 2.5 wt%, 2.6 wt%, 2.8 wt%, or the like, in the granulation process.

The content of the binder is too small, the pellets are not easy to form, the strength of the raw pellets is too low, and the raw pellets are easy to break in the transfer process; the content of the binder is too large, the viscosity of the mixture is too large, the forming of the raw material balls is not facilitated, and the raw material balls are easy to adhere to each other.

Preferably, the granulating device is a disk granulator or a round pan granulator.

The equipment for the granulating process is not limited to a disk granulator or a round pan granulator, and the equipment for granulating can be selected by a person skilled in the art according to actual needs. When a disk or round pot granulator is used for granulation, firstly, the powdery raw materials are added, then water is sprayed to form a ball core, then, the powdery raw materials are added, and water is sprayed until the diameter of a material ball reaches a certain degree, and discharging is carried out; the raw materials and water were mixed uniformly by using an extrusion granulation machine, and then granulated.

The invention can control the particle size of the ceramsite raw material ball by adjusting the inclination angle and the rotating speed of the disc (round pot), thereby meeting the requirements of different use occasions on the particle size of the ceramsite.

Preferably, the diameter of the raw meal ball is 5-25 mm. For example 5mm, 8mm, 10mm, 12mm, 15mm, 18mm, 20mm or 22mm etc.

Preferably, in the granulation process, the amount of water added is 6-40 wt% of the mass of the pellet, such as 8 wt%, 10 wt%, 12 wt%, 15 wt%, 16 wt%, 18 wt%, 20 wt%, 22 wt%, 25 wt%, 28 wt%, 30 wt%, 32 wt%, 35 wt%, 38 wt%, etc.

Preferably, the granulation process further comprises adding a pore-forming agent during the mixing process of the mixed material, the water and the binder.

Preferably, the pore-forming agent is added in an amount of less than or equal to 15 wt%, preferably 1-15 wt%, such as 1 wt%, 2 wt%, 5 wt%, 8 wt%, 10 wt%, 12 wt%, or 14 wt%, of the mass of the green pellets during the granulation process.

Preferably, the pore-forming agent comprises any one of carbon materials, carbonates, organic matters and organic sodium salts or a combination of at least two of the same.

According to the invention, the lightweight of the ceramsite is further realized by adding the pore-forming agent, the content of the pore-forming agent is too small, the material balls cannot be effectively expanded, and the bulk density of the obtained ceramsite is too high; the content of the pore-forming agent is too large, and the cylinder pressure strength of the obtained ceramsite is too low.

Preferably, the carbon material includes any one or a combination of at least two of coke, activated carbon, carbon powder and pulverized coal.

Preferably, the carbonate includes any one of sodium carbonate, potassium carbonate, calcium carbonate and magnesium carbonate or a combination of at least two thereof.

Preferably, the organic matter comprises any one of straw, rice hulls and wood chips or a combination of at least two of the foregoing.

Preferably, the organic sodium salt comprises sodium hexametaphosphate and/or sodium dodecylbenzenesulfonate.

Preferably, after the granulation and before the roasting, a process of drying the raw material balls obtained by the granulation is also included.

Preferably, the drying temperature is 80-120 ℃, such as 85 ℃, 88 ℃, 90 ℃, 92 ℃, 95 ℃, 98 ℃, 100 ℃, 105 ℃, 110 ℃, 112 ℃, 115 ℃ or 118 ℃.

In the invention, the raw material balls are fully dried, the water content of the raw material balls is reduced, and the raw material balls are prevented from being cracked due to direct roasting.

Preferably, the drying time is 1-4 h, such as 1.2h, 1.5h, 1.8h, 2h, 2.2h, 2.5h, 2.8h, 3h, 3.2h, 3.5h or 3.8 h.

Preferably, the content of the vanadium extraction tailings of the sodium salt roasting of the stone coal in the mixed material is 50-80 wt%, such as 55 wt%, 58 wt%, 60 wt%, 65 wt%, 68 wt%, 70 wt%, 72 wt%, 75 wt% or 78 wt%.

The content of the stone coal sodium salt roasting vanadium extraction tailings is less than 50 wt%, and the bulk density and the water absorption of the obtained ceramsite do not meet the performance requirements of GB/T17431.1-2010 on the lightweight aggregate; the content of the stone coal sodium salt roasting vanadium extraction tailings is more than 80 wt%, and the bulk density, water absorption and cylinder pressure strength of the obtained ceramsite do not meet the performance requirements of GB/T17431.1-2010 on the lightweight aggregate.

Preferably, SiO in the stone coal sodium salt roasting vanadium extraction tailings in the step (1)₂The content of (B) is 50 to 80 wt%, for example 52 wt%, 55 wt%, 58 wt%, 60 wt%, 62 wt%, 65 wt%, 68 wt%, 70 wt%, 72 wt%, 75 wt% or 78 wt%.

Preferably, Al in the stone coal sodium salt roasting vanadium extraction tailings in the step (1)₂O₃The content is 2 to 15 wt%, for example, 3 wt%, 5 wt%, 6 wt%, 8 wt%, 10 wt%, 12 wt%, 13 wt%, or 14 wt%.

Preferably, in the stone coal sodium salt roasting vanadium extraction tailings in the step (1), Fe₂O₃、CaO、MgO、K₂O and Na₂The total content of O is 5 to 30 wt%, for example 6 wt%, 8 wt%, 10 wt%, 12 wt%, 15 wt%, 18 wt%, 20 wt%, 22 wt%, 25 wt%, or 28 wt%.

Preferably, the mixing of step (1) is a milling mixing.

Preferably, the particle size of the mixed material is not more than 80 meshes, preferably 80-300 meshes, such as 80 meshes, 100 meshes, 120 meshes, 140 meshes, 160 meshes, 180 meshes, 200 meshes, 240 meshes or 260 meshes.

The granularity of the raw materials influences the sintering process of the ceramsite, further influences the performance of the ceramsite, and the invention comprehensively considers the performance of the ceramsite and the production cost and determines the proper granularity range.

Preferably, the aluminum-containing adjuvant comprises fly ash.

Preferably, the content of the fly ash in the mixed material is 10-30 wt%, such as 12 wt%, 15 wt%, 16 wt%, 18 wt%, 20 wt%, 22 wt%, 25 wt% or 28 wt%.

The fly ash in the mixed material is rich in silicon-aluminum components, can effectively adjust the proportion of silicon-aluminum and alkali metal in the raw materials, is beneficial to forming an aluminosilicate phase after sintering the raw material balls, is matched with the tailings of sodium salt roasting vanadium extraction of stone coal, and can effectively realize the improvement of the strength of ceramsite and the fixation of alkali metal.

Preferably, the aluminum-containing auxiliary material further comprises red mud and/or aluminum ash.

Preferably, the red mud content in the mixed material is 0 to 30 wt%, preferably 5 to 25 wt%, such as 6 wt%, 8 wt%, 10 wt%, 12 wt%, 15 wt%, 16 wt%, 18 wt%, 20 wt%, 22 wt%, 23 wt%, 24 wt%, or the like.

Preferably, the content of the aluminum ash in the mixed material is 0 to 20 wt%, preferably 4 to 16 wt%, such as 5 wt%, 8 wt%, 10 wt%, 12 wt%, 13 wt%, 14 wt%, or 15 wt%.

Preferably, the aluminum-containing auxiliary materials comprise fly ash, red mud and aluminum ash.

The red mud is solid waste slag discharged from the alumina industry, and the aluminum ash is slag generated in the electrolytic aluminum or cast aluminum production process.

Preferably, SiO in the fly ash₂The content of (B) is 30 to 55 wt%, for example 32 wt%, 35 wt%, 38 wt%, 40 wt%, 42 wt%, 45 wt%, 48 wt%, 50 wt% or 52 wt%.

Preferably, Al in the fly ash₂O₃The content of (B) is 20 to 50 wt%, for example 22 wt%, 25 wt%, 28 wt%, 30 wt%, 32 wt%, 35 wt%, 38 wt%, 40 wt%, 42 wt%, 45 wt% or 48 wt%.

Preferably, Al in the red mud₂O₃The content of (B) is not less than 5 wt%, preferably 5 to 30 wt%, for example, 8 wt%, 10 wt%, 12 wt%, 14 wt%, 15 wt%, 16 wt%, 18 wt%, 20 wt%, 22 wt%, 25 wt%, or 28 wt%.

Preferably, Fe in the red mud₂O₃、CaO、MgO、K₂O and Na₂The total content of O is 30 to 65 wt%, for example 32 wt%, 35 wt%, 38 wt%, 40 wt%, 42 wt%, 45 wt%, 48 wt%, 50 wt%, 52 wt%, 55 wt%, 58 wt%, 60 wt% or 62 wt%, etc.

Preferably, Al in the aluminum ash₂O₃The content of (B) is 20 to 80 wt%, for example 22 wt%, 25 wt%, 28 wt%, 30 wt%, 35 wt%, 38 wt%, 40 wt%, 45 wt%, 50 wt%, 55 wt%, 60 wt%, 65 wt%, 70 wt%, or 75 wt%.

As a preferred technical scheme, the preparation method of the light high-strength ceramsite comprises the following steps:

(1) mixing materials: grinding and mixing 50-80 wt% of stone coal sodium salt roasting vanadium extraction tailings, 10-30 wt% of fly ash, 0-30 wt% of red mud and 0-20 wt% of aluminum ash to obtain a mixed material with the granularity of 80-300 meshes;

(2) and (3) granulation: mixing the mixed material obtained in the step (1) with water, a binder and a pore-forming agent, and granulating by using granulation equipment to obtain raw material balls, wherein the addition amount of the binder is 0.01-3 wt% of the mass of the raw material balls, the addition amount of the water is 6-40 wt% of the mass of the raw material balls, and the addition amount of the pore-forming agent is 1-15 wt% of the mass of the raw material balls;

(3) and (3) drying: drying the raw material balls obtained by granulation at the temperature of 80-120 ℃ for 1-4 h to obtain dry material balls;

(4) roasting: raising the temperature of the dry material balls to 300-550 ℃ at a heating rate of 5-30 ℃/min, preserving heat for 1-50 min, then raising the temperature to 1025-1300 ℃ at a heating rate of 5-25 ℃/min, and preserving heat for 1-50 min;

(5) and (3) cooling: and cooling the roasted product to room temperature along with the furnace, and discharging to obtain the light high-strength ceramsite.

FIG. 1 is a schematic view of the process for preparing light-weight high-strength ceramsite, and it can be seen from the figure that the light-weight high-strength ceramsite can be obtained by mixing, granulating, drying, roasting and cooling.

The invention also aims to provide the light high-strength ceramsite which is obtained by the preparation method.

Preferably, the bulk density of the light high-strength ceramsite is 500-1000 kg/m³For example 520kg/m³、550kg/m³、580kg/m³、600kg/m³、650kg/m³、700kg/m³、750kg/m³、800kg/m³、850kg/m³、900kg/m³Or 950kg/m³And the like.

Preferably, the water absorption of the light high-strength ceramsite is 0.5-10% for 1 hour, such as 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8% or 9%.

Preferably, the cylinder pressure strength of the light high-strength ceramsite is 5-25 MPa, such as 6MPa, 8MPa, 10MPa, 12MPa, 15MPa, 16MPa, 18MPa, 20MPa, 21MPa, 22MPa or 24 MPa.

The third purpose of the invention is to provide the use of the light-weight high-strength ceramsite described in the second purpose, wherein the light-weight high-strength ceramsite is used in the field of building materials, preferably any one or a combination of at least two of heat insulating materials, sound insulating materials, heat insulating materials and refractory materials in the field of building materials.

Compared with the prior art, the invention has the following beneficial effects:

(1) the invention realizes the harmless and resource treatment of industrial waste, saves natural resources and reduces production cost.

(2) The invention selects the types of auxiliary materials, adjusts the proportion of each component in the raw materials and auxiliary materials, adopts a two-section roasting sintering system, and regulates and controls the sintering and sintering expansion processes of the ceramsite and the high-temperature conversion process of alkali metal, thereby being beneficial to obtaining the ceramsite with a hard enamel layer on the surface and a large number of closed micropores in the ceramsite and promoting most of the alkali metal to react to generate water-insoluble substances on the other hand, and further being capable of preparing the ceramsite with the bulk density of 500-1000 kg/m³The water absorption rate of 1 hour is 0.5-10.0%, the cylinder pressure strength is 5.0-25.0 MPa, the boiling mass loss is less than 5%, and the requirements of GB/T17431.1-2010 lightweight aggregate and the test method part 1 thereof are met: light-weight high-strength ceramsite required by the light aggregate.

Drawings

FIG. 1 is a schematic view of the process for preparing light high-strength ceramsite.

Detailed Description

For the purpose of facilitating an understanding of the present invention, the present invention will now be described by way of examples. It should be understood by those skilled in the art that the examples are only for the understanding of the present invention and should not be construed as the specific limitations of the present invention.

Example 1

The preparation method of the light high-strength ceramsite comprises the following steps:

vanadium extraction tail of sodium roasting of stone coal used in the embodimentThe composition of the slag (inorganic substances in terms of oxides) is as follows: SiO 2₂74.31 wt% of Al₂O₃5.11 wt% of Fe₂O₃2.54 wt%, CaO 6.32 wt%, MgO 1.03 wt%, K₂O content 1.05 wt%, Na₂O content 1.23 wt%, SO₃The content is 6.11 wt%, the content of C is 1.05 wt%, and the content of other impurities is 1.25 wt%; SiO of fly ash₂52.55 wt% of Al₂O₃37.10 wt% of Fe₂O₃2.87 wt%, CaO 2.58 wt%, MgO 0.44 wt%, K₂O content 0.81 wt%, Na₂O content 0.25 wt%, SO₃The content is 1.02wt percent, and the content of other impurities is 2.37wt percent; the red mud comprises the following components (inorganic matters are calculated by oxides): SiO 2₂22.31 wt% of Al₂O₃12.61 wt% Fe₂O₃10.02 wt%, CaO 47.55 wt%, MgO 1.36 wt%, K₂O content 0.35 wt%, Na₂O content 2.11 wt%, SO₃The content is 1.16 wt%, and the content of other impurities is 2.53 wt%; the composition of the aluminum ash (inorganic substances are calculated by oxides) is as follows: SiO 2₂8.86 wt% of Al₂O₃69.72 wt.% Fe₂O₃0.97 wt%, CaO 1.14 wt%, MgO 4.89 wt%, K₂O content 1.63 wt%, Na₂O content 9.94 wt%, SO₃The content was 0.71 wt%, and the content of other impurities was 2.14 wt%.

(1) Mixing materials: grinding and mixing the stone coal sodium salt roasting vanadium extraction tailings, the fly ash, the red mud and the aluminum ash according to the mass percentage of 60:20:10:10 to obtain a mixed material with the granularity of 100 meshes;

(2) and (3) granulation: mixing the mixed material in the step (1), polyvinyl alcohol and water, and granulating by using a disc granulator to obtain raw material balls with the average particle size of 8mm, wherein the addition amount of the polyvinyl alcohol is 0.5 wt% of the mass of the raw material balls, and the addition amount of the water is 20 wt% of the mass of the raw material balls;

(3) and (3) drying: drying the raw material balls obtained by granulation at 105 ℃ for 2.5 hours to obtain dry material balls;

(4) roasting: heating the dry material ball to 400 ℃ at the heating rate of 10 ℃/min, preserving heat for 20min, then heating to 1050 ℃ at the heating rate of 10 ℃/min, and preserving heat for 20 min;

Example 2

the composition (inorganic matters are calculated by oxides) of the vanadium extraction tailings of the sodium roasting of the stone coal used in the embodiment is as follows: SiO 2₂72.13 wt% of Al₂O₃8.32 wt% of Fe₂O₃5.12 wt%, CaO 1.67 wt%, MgO 1.28 wt%, K₂O content 3.13 wt%, Na₂O content 2.36 wt%, SO₃The content of C is 3.12 wt%, the content of C is 0.51 wt%, and the content of other impurities is 2.36 wt%; SiO of fly ash₂54.09 wt% of Al₂O₃35.46 wt% Fe₂O₃3.06 wt%, CaO 2.55 wt%, MgO 0.47 wt%, K₂O content 0.71 wt%, Na₂O content 0.34 wt%, SO₃The content is 0.71wt percent, and the content of other impurities is 2.61wt percent; the red mud comprises the following components (inorganic matters are calculated by oxides): SiO 2₂22.31 wt% of Al₂O₃12.61 wt% Fe₂O₃10.02 wt%, CaO 47.55 wt%, MgO 1.36 wt%, K₂O content 0.35 wt%, Na₂O content 2.11 wt%, SO₃The content is 1.16 wt%, and the content of other impurities is 2.53 wt%; the composition of the aluminum ash (inorganic substances are calculated by oxides) is as follows: SiO 2₂8.86 wt% of Al₂O₃69.72 wt.% Fe₂O₃0.97 wt%, CaO 1.14 wt%, MgO 4.89 wt%, K₂O content 1.63 wt%, Na₂O content 9.94 wt%, SO₃The content was 0.71 wt%, and the content of other impurities was 2.14 wt%.

(1) Mixing materials: grinding and mixing the stone coal sodium salt roasting vanadium extraction tailings, the fly ash, the red mud and the aluminum ash according to the mass percent of 68:12:10:10 to obtain a mixed material with the granularity of 120 meshes;

(2) and (3) granulation: mixing the mixed material in the step (1), soluble starch, water, hydroxypropyl methyl cellulose and sodium carbonate, and granulating by using a round pot granulator to obtain raw material balls with the average particle size of 11mm, wherein the adding amount of the soluble starch is 0.5 wt% of the mass of the raw material balls, the adding amount of the water is 18 wt% of the mass of the raw material balls, the adding amount of the sodium carbonate is 5 wt% of the mass of the raw material balls, and the adding amount of the hydroxypropyl methyl cellulose is 1 wt% of the mass of the raw material balls;

(3) and (3) drying: drying the raw material balls obtained by granulation at 100 ℃ for 3h to obtain dry material balls;

(4) roasting: heating the dry material ball to 500 ℃ at the heating rate of 10 ℃/min, preserving the heat for 15min, then heating to 1100 ℃ at the heating rate of 15 ℃/min, and preserving the heat for 15 min;

Example 3

the composition (inorganic matters are calculated by oxides) of the vanadium extraction tailings of the sodium roasting of the stone coal used in the embodiment is as follows: SiO 2₂69.68 wt% of Al₂O₃7.46 wt% of Fe₂O₃4.16 wt%, CaO 6.04 wt%, MgO 0.83 wt%, K₂O content 2.51 wt%, Na₂O content 4.54 wt%, SO₃The content is 1.59 wt%, the content of C is 0.62 wt%, and the content of other impurities is 2.57 wt%; the composition of the fly ash (inorganic substances are calculated by oxides) is as follows: SiO 2₂50.08 wt% of Al₂O₃41.20 wt% Fe₂O₃2.99 wt%, CaO 2.16 wt%, MgO 0.32 wt%, K₂O content 0.60 wt%, Na₂O content 0.02 wt%, SO₃The content is 0.45 wt%, and the content of other impurities is2.17 wt%; the red mud comprises the following components (inorganic matters are calculated by oxides): SiO 2₂22.31 wt% of Al₂O₃12.61 wt% Fe₂O₃10.02 wt%, CaO 47.55 wt%, MgO 1.36 wt%, K₂O content 0.35 wt%, Na₂O content 2.11 wt%, SO₃The content was 1.16 wt%, and the content of other impurities was 2.53 wt%.

(1) Mixing materials: grinding and mixing the stone coal sodium salt roasting vanadium extraction tailings, the fly ash and the red mud according to the mass percent of 50:20:30 to obtain a mixed material with the granularity of 180 meshes;

(2) and (3) granulation: mixing the mixed material obtained in the step (1), sesbania powder and water, and granulating by using a disc granulator to obtain raw material balls with the average particle size of 7mm, wherein the addition amount of the sesbania powder is 2 wt% of the mass of the raw material balls, and the addition amount of the water is 15 wt% of the mass of the raw material balls;

(3) and (3) drying: drying the raw material balls obtained by granulation at 110 ℃ for 2h to obtain dry material balls;

(4) roasting: heating the dry material ball to 450 ℃ at a heating rate of 15 ℃/min, preserving heat for 20min, then heating to 1025 ℃ at a heating rate of 10 ℃/min, and preserving heat for 10 min;

Example 4

the composition of the tailings, fly ash and aluminum ash obtained by sodium salt roasting of stone coal used in the present example is the same as that of example 1.

(1) Mixing materials: grinding and mixing the stone coal sodium salt roasting vanadium extraction tailings, the fly ash and the aluminum ash according to the mass percent of 70:10:20 to obtain a mixed material with the granularity of 100 meshes;

(2) and (3) granulation: mixing the mixed material in the step (1), hydroxypropyl methyl cellulose, xanthan gum, water and carbon powder, and granulating by using a round pot granulator to obtain raw material balls with the average particle size of 22mm, wherein the addition of the xanthan gum is 0.5 wt% of the mass of the raw material balls, the addition of the water is 20 wt% of the mass of the raw material balls, the addition of the carbon powder is 15 wt% of the mass of the raw material balls, and the addition of the hydroxypropyl methyl cellulose is 0.5 wt% of the mass of the raw material balls;

(3) and (3) drying: drying the raw material balls obtained by granulation at 120 ℃ for 1h to obtain dry material balls;

(4) roasting: heating the dry material ball to 300 ℃ at the heating rate of 5 ℃/min, preserving heat for 50min, then heating to 1300 ℃ at the heating rate of 10 ℃/min, and preserving heat for 1 min;

Example 5

the composition of the vanadium extraction tailings, the fly ash, the red mud and the aluminum ash of the sodium roasting of the stone coal used in the embodiment is the same as that of the embodiment 2.

(1) Mixing materials: grinding and mixing the stone coal sodium salt roasting vanadium extraction tailings, the fly ash, the red mud and the aluminum ash according to the mass percentage of 60:25:10:5 to obtain a mixed material with the granularity of 200 meshes;

(2) and (3) granulation: mixing the mixed material in the step (1), soluble starch and water, and granulating by using a round-pot granulator to obtain raw material balls with the average particle size of 12mm, wherein the adding amount of the soluble starch is 2.0 wt% of the mass of the raw material balls, and the adding amount of the water is 40 wt% of the mass of the raw material balls;

(3) and (3) drying: drying the raw material balls obtained by granulation at 80 ℃ for 4h to obtain dry material balls;

(4) roasting: heating the dry material ball to 550 ℃ at the heating rate of 30 ℃/min, then heating to 1100 ℃ at the heating rate of 25 ℃/min, and preserving heat for 50 min;

Example 6

the composition of the vanadium extraction tailings, the fly ash, the red mud and the aluminum ash of the sodium roasting of the stone coal used in the embodiment is the same as that of the embodiment 1.

(1) Mixing materials: grinding and mixing the stone coal sodium salt roasting vanadium extraction tailings, the fly ash, the red mud and the aluminum ash according to the mass percent of 75:12:8:5 to obtain a mixed material with the granularity of 160 meshes;

(2) and (3) granulation: mixing the mixed material in the step (1), polyvinyl alcohol and water, and granulating by using a round pot granulator to obtain raw material balls with the average particle size of 23mm, wherein the addition amount of the polyvinyl alcohol is 3.0 wt% of the mass of the raw material balls, and the addition amount of the water is 40 wt% of the mass of the raw material balls;

(4) roasting: heating the dry material ball to 450 ℃ at the heating rate of 15 ℃/min, preserving heat for 20min, then heating to 1250 ℃ at the heating rate of 20 ℃/min, and preserving heat for 10 min;

Example 7

the composition of the tailings and fly ash for vanadium extraction by sodium salt roasting of stone coal used in the present example is the same as that in example 3, and the composition of red mud and aluminum ash is the same as that in example 1.

(1) Mixing materials: grinding and mixing the stone coal sodium salt roasting vanadium extraction tailings, the fly ash, the red mud and the aluminum ash according to the mass percentage of 60:30:6:4 to obtain a mixed material with the granularity of 300 meshes;

(2) and (3) granulation: mixing the mixed material obtained in the step (1), xanthan gum and water, and granulating by using a disc granulator to obtain raw material balls with the average particle size of 13mm, wherein the addition amount of the xanthan gum is 2 wt% of the mass of the raw material balls, and the addition amount of the water is 20 wt% of the mass of the raw material balls;

(3) and (3) drying: drying the raw material balls obtained by granulation at 110 ℃ for 2.0h to obtain dry material balls;

(4) roasting: heating the dry material ball to 500 ℃ at the heating rate of 25 ℃/min, preserving heat for 1min, then heating to 1125 ℃ at the heating rate of 5 ℃/min, and preserving heat for 40 min;

Example 8

(1) Mixing materials: grinding and mixing the stone coal sodium salt roasting vanadium extraction tailings, the fly ash, the red mud and the aluminum ash according to the mass percent of 75:15:5:5 to obtain a mixed material with the granularity of 200 meshes;

(2) and (3) granulation: mixing the mixed material in the step (1), hydroxypropyl methyl cellulose and water, and granulating by using a disc granulator to obtain raw material balls with the average particle size of 20mm, wherein the addition amount of the hydroxypropyl methyl cellulose is 0.01 wt% of the mass of the raw material balls, and the addition amount of the water is 10 wt% of the mass of the raw material balls;

(3) and (3) drying: drying the raw material balls obtained by granulation at 90 ℃ for 3.5 hours to obtain dry material balls;

(4) roasting: heating the dry material ball to 400 ℃ at the heating rate of 30 ℃/min, preserving heat for 40min, then heating to 1150 ℃ at the heating rate of 10 ℃/min, and preserving heat for 35 min;

Example 9

(1) Mixing materials: grinding and mixing the stone coal sodium salt roasting vanadium extraction tailings, the fly ash, the red mud and the aluminum ash according to the mass percentage of 80:10:4:6 to obtain a mixed material with the granularity of 120 meshes;

(2) and (3) granulation: mixing the mixed material in the step (1), soluble starch, water and carbon powder, and granulating by using a round pot granulator to obtain raw material balls with the average particle size of 15mm, wherein the adding amount of the soluble starch is 1 wt% of the mass of the raw material balls, the adding amount of the water is 30 wt% of the mass of the raw material balls, and the adding amount of the carbon powder is 10.0 wt% of the mass of the raw material balls;

(4) roasting: heating the dry material ball to 550 ℃ at a heating rate of 15 ℃/min, preserving heat for 50min, then heating to 1050 ℃ at a heating rate of 5 ℃/min, and preserving heat for 30 min;

Example 10

the composition of the tailings and fly ash for vanadium extraction by sodium salt roasting of stone coal used in the example is the same as that in example 3, and the composition of red mud and aluminum ash is the same as that in example 2.

(1) Mixing materials: grinding and mixing the stone coal sodium salt roasting vanadium extraction tailings, the fly ash, the red mud and the aluminum ash according to the mass percent of 75:15:4:6 to obtain a mixed material with the granularity of 180 meshes;

(2) and (3) granulation: mixing the mixed material obtained in the step (1), xanthan gum and water, and granulating by using a disc granulator to obtain raw material balls with the average particle size of 10mm, wherein the addition amount of the xanthan gum is 0.5 wt% of the mass of the raw material balls, and the addition amount of the water is 20 wt% of the mass of the raw material balls;

(4) roasting: heating the dry material ball to 450 ℃ at the heating rate of 25 ℃/min, preserving heat for 5min, then heating to 1130 ℃ at the heating rate of 10 ℃/min, and preserving heat for 10 min;

Example 11

The difference from the embodiment 1 is that the mass percentages of the stone coal sodium salt roasting vanadium extraction tailings, the fly ash, the red mud and the aluminum ash are 30:30:20: 20.

Example 12

The difference from the embodiment 1 is that the mass percentage of the stone coal sodium salt roasting vanadium extraction tailings, the fly ash, the red mud and the aluminum ash is 84:12:2: 2.

Example 13

The difference from the embodiment 1 is that the mass percentage of the vanadium extraction tailings, the red mud and the aluminum ash of the sodium roasting of the stone coal is 60:20: 20.

Example 14

The difference from example 1 is that the two-stage firing in step (4) is replaced by one-stage firing: and (3) heating the dry material ball to 1050 ℃ at the heating rate of 10 ℃/min, and preserving the temperature for 20 min.

Example 15

The difference from example 1 is that the first temperature in step (4) is 800 ℃.

Example 16

The difference from example 1 is that the second temperature in step (4) is 900 ℃.

Example 17

The difference from the example 1 is that the raw material ball in the step (2) contains a pore-forming agent sodium carbonate, and the content of the sodium carbonate is 2 wt% of the mass of the raw material ball.

Comparative example 1

The difference from example 1 is that the aluminium-containing adjuvants (fly ash, red mud and aluminium ash) are replaced by an equal amount of clay, the composition of which (inorganic substances are all calculated as oxides) is as follows: SiO 2₂55.21 wt% of Al₂O₃26.25 wt.% of Fe₂O₃5.32 wt%, CaO 5.34 wt%, MgO 1.25 wt%, K₂O content 1.05 wt%, Na₂O content 1.78 wt%, SO₃The content was 0.81 wt%, and the content of other impurities was 2.99 wt%.

And (3) performance testing:

the prepared light high-strength ceramsite is subjected to the following performance tests:

(1) bulk density: according to GB/T17431.2-2010 lightweight aggregate and test method part 2: the test is carried out according to the specification of ' 6 bulk density ' in the test method of light aggregate ';

(2) water absorption for 1 h: according to GB/T17431.2-2010 lightweight aggregate and test method part 2: the test is carried out according to the regulation of '11 water absorption rate' in the test method of light aggregate;

(3) barrel pressure strength: according to GB/T17431.2-2010 lightweight aggregate and test method part 2: the test is carried out according to the specification of '9 cylinder pressure strength' in the test method of light aggregate;

(4) boiling mass loss rate: according to GB/T17431.2-2010 lightweight aggregate and test method part 2: the "15 boil mass loss" specification in the lightweight aggregate test method "was tested.

TABLE 1

As can be seen from Table 1, the lightweight high-strength ceramsite obtained by the method provided by the invention has low bulk density (500-1000 kg/m)³) Low water absorption (0.5-10%), low boiling quality loss rate (<5 percent) and has higher cylinder pressure strength (5-25 MPa), thereby meeting the use requirement of the ceramsite.

As can be seen from Table 1, in example 11 of the present invention, compared with example 1, the bulk density and water absorption of the obtained ceramsite are increased, and the barrel pressure strength is significantly reduced, which is caused by the low ratio of the tailings from sodium roasting of stone coal to extract vanadium, so that Al in the raw material is present₂O₃The content is relatively high, the required sintering temperature is increased, and the sintering degree is reduced, so that the product performance difference is caused; compared with the embodiment 1, the ceramsite obtained in the embodiment 12 has higher bulk density and water absorption, lower cylinder pressure strength and higher boiling quality loss, which are caused by overhigh proportion of the tailings generated by sodium roasting vanadium extraction of stone coal₂The content is relatively high, the required sintering temperature is higher, and the sintering degree is reduced under the same process conditions as example 1, thereby causing the product performance difference.

As can be seen from table 1, in example 13 of the present invention, compared to example 1, the bulk density and water absorption of the obtained ceramsite are increased, the barrel pressure strength is reduced, and the boiling quality loss is increased, because the embodiment 13 does not contain fly ash, but the addition of fly ash in the preparation method of the present application can effectively increase the content of aluminosilicate phase in the sintered ceramsite, increase the barrel pressure strength, and simultaneously, play a role in fixing alkali metal.

As can be seen from Table 1, in example 14 of the present invention, compared with example 1, the bulk density and water absorption of the obtained ceramsite are slightly increased, and the cylinder pressure strength is slightly reduced, because the ceramsite is subjected to a first-stage calcination, and the gas-generating component ratio in the raw materials is further adjusted without a heat preservation process when the ceramsite reaches the first temperature in the temperature raising process, such that the performance of the ceramsite is slightly reduced.

As can be seen from Table 1, in example 15 of the present invention, compared with example 1, the obtained ceramsite has higher bulk density and water absorption, because the first temperature is too high, the gas production component in the raw material is more lost, which is not favorable for the later expansion of the ceramsite; compared with the example 1, the haydite obtained in the example 16 of the present invention has significantly increased bulk density and water absorption, and significantly reduced cylinder pressure strength, because the second temperature is too low, and the sintering degree of the pellets is too low.

As can be seen from Table 1, the ceramsite bulk density obtained in example 17 of the present invention is lower than that obtained in example 1, which indicates that the ceramsite bulk density can be effectively reduced by adding the pore-forming agent through the preparation method of the present invention.

As can be seen from Table 1, in comparative example 1 of the present invention, compared with example 1, the bulk density and water absorption of the obtained ceramsite are significantly increased, the cylinder strength is significantly reduced, and the boiling quality loss rate is significantly increased due to Al contained in the clay₂O₃The components are less, and the generation of an aluminosilicate phase is not facilitated under the same process conditions, so that the improvement of the performance of the ceramsite is influenced.

The applicant states that the present invention is illustrated by the above examples to show the detailed process equipment and process flow of the present invention, but the present invention is not limited to the above detailed process equipment and process flow, i.e. it does not mean that the present invention must rely on the above detailed process equipment and process flow to be implemented. It should be understood by those skilled in the art that any modification of the present invention, equivalent substitutions of the raw materials of the product of the present invention, addition of auxiliary components, selection of specific modes, etc., are within the scope and disclosure of the present invention.

Claims

1. The preparation method of the light high-strength ceramsite is characterized by comprising the following steps of:

2. The method according to claim 1, wherein the firing of the step (2) is a two-stage firing comprising: increasing the temperature to a first temperature at a first temperature-increasing rate, and then increasing the temperature to a second temperature at a second temperature-increasing rate;

preferably, the first heating rate is 5-30 ℃/min;

preferably, the first temperature is less than or equal to 550 ℃, and preferably 300-550 ℃;

preferably, the heat preservation time at the first temperature is 1-50 min;

preferably, the second heating rate is 5-25 ℃/min;

preferably, the second temperature is more than or equal to 1025 ℃, preferably 1025-1300 ℃;

preferably, the heat preservation time at the second temperature is 1-50 min;

preferably, the roasting process further comprises a cooling process;

preferably, the cooling is furnace cooling to room temperature.

3. The method according to claim 1 or 2, wherein the granulating of step (2) comprises: mixing the mixed material, water and a binder, and granulating by using granulation equipment to obtain raw material balls;

preferably, the binder comprises any one or a combination of at least two of hydroxypropyl methylcellulose, polyvinyl alcohol, sodium silicate, soluble starch, xanthan gum and sesbania powder;

preferably, in the granulation process, the addition amount of the binder is 0.01-3 wt% of the mass of the feed ball;

preferably, the granulating equipment is a disk granulator or a round pan granulator;

preferably, the diameter of the raw meal ball is 5-25 mm.

4. The preparation method according to claim 3, wherein in the granulation process, the addition amount of water is 6-40 wt% of the mass of the pellets;

preferably, in the granulation process, a pore-forming agent is added in the mixing process of the mixed material, the water and the binder;

preferably, in the granulation process, the addition amount of the pore-forming agent is less than or equal to 15 wt% of the mass of the raw material ball, and preferably 1-15 wt%;

preferably, the pore-forming agent comprises any one or a combination of at least two of a carbon material, a carbonate, an organic matter and an organic sodium salt;

preferably, the carbon material comprises any one or a combination of at least two of coke, activated carbon, carbon powder and coal powder;

preferably, the carbonate comprises any one or a combination of at least two of sodium carbonate, potassium carbonate, calcium carbonate and magnesium carbonate;

preferably, the organic matter comprises any one or a combination of at least two of straw, rice hulls and wood chips;

preferably, the organic sodium salt comprises sodium hexametaphosphate and/or sodium dodecylbenzenesulfonate;

preferably, after the granulation and before the roasting, the method further comprises a process of drying the raw material balls obtained by the granulation;

preferably, the drying temperature is 80-120 ℃;

preferably, the drying time is 1-4 h.

5. The preparation method according to one of claims 1 to 4, characterized in that the content of the tailings of vanadium extraction in the sodium salt roasting of stone coal in the mixed material is 50-80 wt%;

preferably, SiO in the stone coal sodium salt roasting vanadium extraction tailings in the step (1)₂The content of (A) is 50-80 wt%;

preferably, Al in the stone coal sodium salt roasting vanadium extraction tailings in the step (1)₂O₃The content is 2-15 wt%;

preferably, in the stone coal sodium salt roasting vanadium extraction tailings in the step (1), Fe₂O₃、CaO、MgO、K₂O and Na₂The total content of O is 5-30 wt%;

preferably, the mixing of step (1) is a milling mixing;

preferably, the particle size of the mixed material is less than or equal to 80 meshes, and preferably 80-300 meshes.

6. The method according to any one of claims 1 to 5, wherein the aluminum-containing auxiliary material comprises fly ash;

preferably, in the mixed material, the content of the fly ash is 10-30 wt%;

preferably, the aluminum-containing auxiliary material further comprises red mud and/or aluminum ash;

preferably, in the mixed material, the content of the red mud is 0-30 wt%, preferably 5-25 wt%;

preferably, the content of the aluminum ash in the mixed material is 0-20 wt%, and preferably 4-16 wt%;

preferably, the aluminum-containing auxiliary materials comprise fly ash, red mud and aluminum ash;

preferably, SiO in the fly ash₂The content of (A) is 30-55 wt%;

preferably, Al in the fly ash₂O₃The content of (A) is 20-50 wt%;

preferably, Al in the red mud₂O₃The content of (A) is more than or equal to 5 wt%, preferably 5-30 wt%;

preferably, in the red mudFe₂O₃、CaO、MgO、K₂O and Na₂The total content of O is 30-65 wt%;

preferably, Al in the aluminum ash₂O₃The content of (B) is 20-80 wt%.

7. Preparation process according to one of claims 1 to 6, characterized in that it comprises the following steps:

8. Light-weight high-strength ceramsite is characterized by being prepared by the preparation method of any one of claims 1-7.

9. The light-weight high-strength ceramsite according to claim 8, wherein the bulk density of the light-weight high-strength ceramsite is 500-1000 kg/m³；

Preferably, the water absorption of the light high-strength ceramsite is 0.5-10% within 1 hour;

preferably, the cylinder pressure strength of the light high-strength ceramsite is 5-25 MPa.

10. Use of the light-weight high-strength ceramsite according to claim 8 or 9, wherein the light-weight high-strength ceramsite is used in the field of building materials, preferably any one or a combination of at least two of heat insulating materials, sound insulating materials, heat insulating materials and fire resistant materials in the field of building materials.