CN110627521A - Lightweight high-strength ceramsite prepared from slate as raw material and preparation method thereof - Google Patents

Abstract

The invention discloses a light-weight high-strength ceramsite prepared from slate as a raw material and a preparation method thereof, and relates to the technical field of preparation of building materials. According to the mass percentage, the raw material ratio is 50%-90% of slate, pulverized coal Ash 5%‑30%, metal magnesium slag 2%‑6%, oil shale semi-coke 1%‑10%, dolomite 1%‑4%. In the present invention, the fly ash added to the lightweight high-strength ceramsite with slate as raw material can _both reduce the _SiO2 content and increase the _Al2O3 content, which can not only reduce the occupation of a large amount of land by the accumulation of slate tailings, and reduce the They pose a serious threat to ecology, the environment and human health. They also solve the problems of high bulk density, high water absorption and low cylinder compressive strength that existed in the ceramsite products on the market in the past, and improve the protection against slate tailings and metal magnesium slag. , The utilization value of oil shale semi-coke and fly ash, turning solid waste into treasure, suitable for industrial production.

Description

Lightweight high-strength ceramsite prepared from slate as raw material and preparation method thereof

technical field

The invention relates to the technical field of preparation of building materials, in particular to a light-weight high-strength ceramsite prepared from slate as a raw material and a preparation method thereof.

Background technique

As a light aggregate, ceramsite has the characteristics of low density, high strength, high water absorption, heat preservation, heat insulation, shock resistance, and fire resistance. It can also be used as a medium for soilless cultivation in agriculture and gardens, as well as building materials such as bridge decks, hollow non-load-bearing blocks or concrete components. In the prior art, the known ceramsite generally uses clay, biological sludge, etc. as the main raw materials, and is formed by high-temperature roasting and puffing. Due to the limited source of raw materials, the known ceramsite products still have serious environmental pollution in the actual preparation process. There are many problems such as large size, high production cost and high energy consumption, and the cylinder compressive strength of the product itself is also low (3-5MPa).

As a building decoration material, slate has been exploited and utilized in large quantities. But the mining yield of slate is extremely low, only 8-10%. In the process of mining and production of slate, the waste is as high as 90%. Despite the adoption of circulating water treatment and secondary sedimentation, the accumulation of waste accumulates like a mountain, seriously occupying a large amount of cultivated land. However, slate contains chemical components such as SiO ₂ , Al ₂ O ₃ , Fe ₂ O ₃ , and MgO, as shown in Table 1. In addition, slate has a larger loss on ignition.

Table 1 Slate chemical composition and content (%)

SiO₂ Al₂O₃ Fe₂O₃ MgO CaO K₂O 61.2-71.3 12.4-18.7 2.8-5.9 0.9-2.2 0.1-0.2 2.4-3.7 Na₂O P₂O₅ MnO TiO₂ LOI 0.5-2.7 0.01-0.06 0.3-1.9 0.2-0.7 2.1-5.6

Magnesium slag is generally a solid waste produced during the smelting of metal magnesium in magnesium factories. About 8-10 tons of magnesium slag are discharged for every ton of metal magnesium produced. How to realize the resource utilization of magnesium slag has become a major theme restricting the development of my country's magnesium industry. The main chemical composition of magnesium slag is CaO and SiO ₂ , and its specific chemical composition is shown in Table 2.

Table 2 Semi-quantitative analysis result table of metallic magnesium slag (%)

CaO Al₂O₃ SiO₂ Fe₂O₃ 55.27-61.87 0.69-1.98 25.21-30.23 3.52-4.56 Na₂O MgO K₂O LOI 0-0.08 5.34-7.86 0-0.28 0.4-3.76

Oil shale semi-coke is a solid product obtained after low-temperature dry distillation and combustion of oil shale, and its chemical composition is shown in Table 3 below. The accumulation of oil shale semi-coke is huge and requires a lot of land. In addition, oil shale semi-coke contains a large amount of heavy metal elements. After rainwater leaching, these elements seriously pollute the surrounding land and water sources, thereby destroying the productive capacity of the soil and thus destroying agricultural production. However, oil shale semi-coke contains a large amount of mineral components, and has a larger loss on ignition and a lighter density.

Table 3 Chemical composition of oil shale semi-coke (%)

SiO₂ Al₂O₃ Fe₂O₃ MgO CaO K₂O 48.16-54.23 12.98-16.28 9.08-16.32 1.02-4.35 1.25-5.23 2.31-4.65 P₂O₅ MnO TiO₂ Na₂O LOI 0.41-1.26 0-0.38 0.37-0.65 0.71-1.87 14.55-23.84

Fly ash is waste residue discharged from thermal power plants, and its chemical composition is shown in Table 4 below. Fly ash emissions are huge, how to reasonably turn these fly ash into treasures is an important task in the current environmental protection work. The fine particles of fly ash float into the air, and the long-distance transportation with the airflow will cause regional pollution to the environment; the toxic and harmful substances in the piled fly ash will infiltrate into surface water and groundwater, causing water pollution; The high salt and high alkalinity of fly ash will lead to salinity of the land, affecting the ecological environment and agricultural production; harmful substances such as heavy metals in fly ash enter the water body through leaching, or are harmful to human health after being ingested by the human body through crops. cause serious harm.

Table 4 Fly ash chemical composition and content (%)

Al₂O₃ SiO₂ Fe₂O₃ K₂O Na₂O MgO CaO LOI 12.8-33.1 38.1-61.7 4.21-10.2 1.23-2.56 0.4-2.3 0.7-1.4 5.0-24.5 0.7-8.1

Contents of the invention

The invention provides a light-weight high-strength ceramsite prepared from slate as a raw material and a preparation method thereof, which not only solve the problems of high bulk density, high water absorption rate and low cylinder compressive strength of ceramsite products, but also can reduce slate tailings Accumulation occupies a large amount of land and reduces the serious threat to ecology, environment and human health.

The invention provides a light-weight high-strength ceramsite prepared from slate as a raw material. The ratio of raw materials according to mass percentage is: 50-90% of slate, 5-30% of fly ash, metal Magnesium slag 2-6%, oil shale semi-coke 1-10%, dolomite 1-4%.

Preferably, the chemical composition of the slate includes SiO ₂ , Al ₂ O ₃ , Fe ₂ O ₃ , MgO, CaO, K ₂ O, Na ₂ O, P ₂ O ₅ , MnO, TiO ₂ and LOI.

Preferably, the chemical composition of the metal magnesium slag includes CaO, Al ₂ O ₃ , SiO ₂ , Fe ₂ O ₃ , Na ₂ O, MgO, F and K ₂ O.

A preparation method of light high-strength ceramsite prepared from slate as raw material, comprising the following steps

(1) Weigh 50-90% slate, 5-30% fly ash, 2-6% magnesium metal slag, 1-10% oil shale semi-coke, 1-4% Dolomite, and crushing and grinding the slate to 200 mesh-400 mesh, mixing the above-mentioned raw materials to obtain a mixture;

(2) Put the mixture into the intensive mixer, use a spraying device to spray water on the mixture in the intensive mixer, roll it into a ball, and obtain a wet ball;

(3) drying the wet balls naturally and then drying them in a rotary kiln to obtain dry balls;

(4) Place the dried pellets in a rotary kiln and roast for 1h-2.5h;

(5) Cool the calcined pellets to 75°C-125°C in a rotary kiln, leave the kiln to cool naturally, and then sieve to obtain the finished product.

Preferably, the particle size of the wet material balls in step (2) is less than 15 mm.

Preferably, the drying temperature in the rotary kiln in step (3) is 80°C-200°C.

Preferably, in step (4), the calcination temperature is 1200-1300° C., and the calcination time is 5-10 min.

Preferably, in step (5), the particle size screening range of the finished product is 5-15mm.

In the present invention, the fly ash added to the light high-strength ceramsite with slate as raw material can not only reduce the content of SiO ₂ but also increase the content of Al ₂ O ₃ , so that the ceramsite can be guaranteed under the condition of high expansion energy of the material ball. Good strength of ceramsite; the Fe ₂ O ₃ component in the formula decomposes to produce a large amount of O ₂ when heated at high temperature, and at the same time Fe ₂ O ₃ can also react with excess C to generate CO gas, which plays a key role in the swelling of ceramsite Function; Na ₂ O, K ₂ O, CaO and MgO and other additives in the formula are high in content and play a fluxing role, which can reduce the firing temperature of ceramsite. At the same time, these additives are also conducive to the formation of liquid phase. Thereby expanding the melting temperature range and improving the quality of ceramsite; the implementation of the technical solution of the present invention can not only reduce the occupation of a large amount of land by the accumulation of slate tailings, alleviate their serious threat to ecology, the environment and human health, but also solve the problem of ceramics on the market in the past. The problems of high bulk density, high water absorption and low cylinder compressive strength in the granular product itself have improved the utilization value of slate tailings and fly ash, turning waste into treasure and suitable for industrial production.

Detailed ways

Example 1

Embodiment 1 of the present invention provides a kind of lightweight high-strength ceramsite with slate as raw material, and its raw material ratio according to mass percentage is:

In this embodiment 1, the light high-strength ceramsite with slate as raw material, the chemical composition and content of the raw material are shown in Table 5 below:

The raw material chemical composition and content (%) involved in table 5 embodiment 1

Its manufacturing method is implemented according to the following steps:

(1) Weigh 80% of slate, 10% of fly ash, 5% of magnesium metal slag, 3% of oil shale semi-coke, and 2% of dolomite according to mass percentage, and crush and grind the slate to 200 mesh, the metal magnesium slag, oil shale semi-coke and dolomite are ground to 200 mesh, and the above raw materials are mixed to obtain a mixture;

(2) Put the mixture into the intensive mixer, spray water on the mixture in the intensive mixer with a spraying device, roll into balls, and obtain wet pellets, wherein the wet pellets have a particle size less than 15 mm;

(3) drying the wet pellets naturally and then drying them in a rotary kiln to obtain dried pellets, wherein the drying temperature in the rotary kiln is 120°C;

(4) Place the dried pellets in a rotary kiln and roast for 1h-2.5h, wherein the roasting temperature is 1250°C and the roasting time is 5min;

(5) Cool the calcined balls to 75°C-125°C in the rotary kiln, and screen after leaving the kiln for natural cooling to obtain the finished product, wherein the particle size screening range of the finished product is 5-15mm.

With reference to the requirements of the experimental conditions of "Light Aggregate", the relevant performance of the product obtained in Example 1 was tested. The lightweight high-strength ceramsite obtained in Example 1 of the present invention has a bulk density of 814kg/m ³ , a water absorption rate of 4.2%, and a cylinder compressive strength of 6.7Mpa, meeting the national standard for lightweight high-strength ceramsite.

Example 2

Embodiment 2 of the present invention provides a kind of lightweight high-strength ceramsite with slate as raw material, and its raw material ratio according to mass percentage is:

In this embodiment 2, the light high-strength ceramsite with slate as raw material, the chemical composition and content of the raw material are shown in Table 6 below:

The raw material chemical composition and content (%) involved in table 6 embodiment 2

chemical composition slate fly ash Magnesium slag Oil Shale Semi-coke dolomite Total SiO₂ 49.35 8.22 1.36 2.44 61.37 Al₂O₃ 9.10 5.96 0.08 0.70 15.84 Fe₂O₃ 4.12 1.10 0.20 0.50 5.92 MgO 1.32 0.13 0.27 0.05 1.77 CaO 0.13 0.92 3.05 0.07 1.12 5.29 K₂O 2.31 0.23 0.00 0.14 2.68 Na₂O 1.54 0.07 0.00 0.05 1.66 P₂O₅ 0.04 0.09 0.00 0.03 0.16 MnO 1.32 0.01 0.00 0.00 1.33 TiO₂ 0.49 0.27 0.00 0.02 0.78 LOI 1.49 0.75 0.02 0.98 3.24

Its manufacturing method is implemented according to the following steps:

(1) Weigh 70% of slate, 18% of fly ash, 5% of magnesium metal slag, 5% of oil shale semi-coke, and 2% of dolomite according to mass percentage, and crush and grind the slate to 200 mesh, the metal magnesium slag, oil shale semi-coke and dolomite are ground to 200 mesh, and the above raw materials are mixed to obtain a mixture;

(2) Put the mixture into the intensive mixer, spray water on the mixture in the intensive mixer with a spraying device, roll into balls, and obtain wet pellets, wherein the wet pellets have a particle size less than 15mm;

(3) drying the wet pellets naturally and then drying them in a rotary kiln to obtain dried pellets, wherein the drying temperature in the rotary kiln is 120°C;

(4) Place the dried pellets in a rotary kiln and roast for 1h-2.5h, wherein the roasting temperature is 1250°C and the roasting time is 5min;

(5) Cool the calcined balls to 75°C-125°C in the rotary kiln, and screen after leaving the kiln for natural cooling to obtain the finished product, wherein the particle size screening range of the finished product is 5-15mm.

With reference to the requirements of the experimental conditions of "Light Aggregate", the relevant performance of the product obtained in Example 2 was tested. The lightweight high-strength ceramsite obtained in Example 2 of the present invention has a bulk density of 765kg/m ³ , a water absorption rate of 4.9%, and a cylinder compressive strength of 6.9Mpa, which meet the national standard for lightweight high-strength ceramsite.

Example 3

Embodiment 3 of the present invention provides a kind of lightweight high-strength ceramsite with slate as raw material, and its raw material ratio according to mass percentage is:

In this embodiment 3, the light high-strength ceramsite with slate as raw material, the chemical composition and content of the raw material are shown in Table 7 below:

The raw material chemical composition and content (%) involved in table 7 embodiment 3

chemical composition slate fly ash Magnesium slag Oil Shale Semi-coke dolomite Total SiO₂ 42.32 12.79 1.36 2.44 58.91 Al₂O₃ 7.80 9.27 0.08 0.70 17.85 Fe₂O₃ 3.53 1.71 0.20 0.50 5.94 MgO 1.13 0.20 0.27 0.05 1.64 CaO 0.11 1.41 3.05 0.07 1.12 5.76 K₂O 1.98 0.36 0.00 0.14 2.48 Na₂O 1.32 0.11 0.00 0.05 1.47 P₂O₅ 0.03 0.14 0.00 0.03 0.21 MnO 1.13 0.01 0.00 0.00 1.15 TiO₂ 0.42 0.41 0.00 0.02 0.86 LOI 1.28 1.17 0.02 0.98 3.45

Its manufacturing method is implemented according to the following steps:

(1) Weigh 60% of slate, 28% of fly ash, 5% of magnesium metal slag, 5% of oil shale semi-coke, and 2% of dolomite according to mass percentage, and crush and grind the slate to 200 mesh, the metal magnesium slag, oil shale semi-coke and dolomite are ground to 200 mesh, and the above raw materials are mixed to obtain a mixture;

(2) Put the mixture into the intensive mixer, spray water on the mixture in the intensive mixer with a spraying device, roll into balls, and obtain wet pellets, wherein the wet pellets have a particle size less than 15 mm;

(3) drying the wet pellets naturally and then drying them in a rotary kiln to obtain dried pellets, wherein the drying temperature in the rotary kiln is 120°C;

(4) Place the dried pellets in a rotary kiln and roast for 1h-2.5h, wherein the roasting temperature is 1260°C and the roasting time is 5min;

(5) Cool the calcined balls to 75°C-125°C in the rotary kiln, and screen after leaving the kiln for natural cooling to obtain the finished product, wherein the particle size screening range of the finished product is 5-15mm.

With reference to the requirements of the experimental conditions of "Light Aggregate", the relevant properties of the product obtained in Example 3 were tested. The lightweight high-strength ceramsite obtained in Example 3 of the present invention has a bulk density of 680kg/m ³ , a water absorption rate of 5.6%, and a cylinder compressive strength of 7.8Mpa, meeting the national standard for lightweight high-strength ceramsite.

Example 4

Embodiment 4 of the present invention provides a kind of lightweight high-strength ceramsite with slate as raw material, and its raw material ratio according to mass percentage is:

In this embodiment 4, the light high-strength ceramsite with slate as raw material, the chemical composition and content of the raw material are shown in Table 8 below:

The raw material chemical composition and content (%) involved in table 8 embodiment 4

Its manufacturing method is implemented according to the following steps:

(1) Weigh 60% of slate, 30% of fly ash, 3% of magnesium metal slag, 5% of oil shale semi-coke, and 2% of dolomite according to mass percentage, and crush and grind the slate to 200 mesh, the metal magnesium slag, oil shale semi-coke and dolomite are ground to 200 mesh, and the above raw materials are mixed to obtain a mixture;

(2) Put the mixture into the intensive mixer, spray water on the mixture in the intensive mixer with a spraying device, roll into balls, and obtain wet pellets, wherein the wet pellets have a particle size less than 15 mm;

(3) drying the wet pellets naturally and then drying them in a rotary kiln to obtain dried pellets, wherein the drying temperature in the rotary kiln is 120°C;

(4) Place the dried pellets in a rotary kiln and roast for 1h-2.5h, wherein the roasting temperature is 1220°C and the roasting time is 5min;

(5) Cool the calcined balls to 75°C-125°C in the rotary kiln, and screen after leaving the kiln for natural cooling to obtain the finished product, wherein the particle size screening range of the finished product is 5-15mm.

With reference to the requirements of the experimental conditions of "Light Aggregate", the relevant properties of the product obtained in Example 4 were tested. The lightweight high-strength ceramsite obtained in Example 4 of the present invention has a bulk density of 653kg/m ³ , a water absorption rate of 6.1%, and a cylinder compressive strength of 7.6Mpa, meeting the national standard for lightweight high-strength ceramsite.

Example 5

Embodiment 5 of the present invention provides a kind of lightweight high-strength ceramsite with slate as raw material, and its raw material ratio according to mass percentage is:

In this embodiment 5, the light high-strength ceramsite with slate as raw material, the chemical composition and content of the raw material are shown in Table 9 below:

The raw material chemical composition and content (%) involved in table 9 embodiment 5

chemical composition slate fly ash Magnesium slag Oil Shale Semi-coke dolomite Total SiO₂ 38.79 13.70 0.82 4.88 58.19 Al₂O₃ 7.15 9.93 0.05 1.40 18.53 Fe₂O₃ 3.24 1.83 0.12 1.00 6.19 MgO 1.04 0.21 0.16 0.10 1.51 CaO 0.10 1.51 1.83 0.14 1.12 4.70 K₂O 1.82 0.39 0.00 0.28 2.49 Na₂O 1.21 0.12 0.00 0.10 1.43 P₂O₅ 0.03 0.15 0.00 0.06 0.24 MnO 1.04 0.01 0.00 0.00 1.05 TiO₂ 0.38 0.44 0.00 0.04 0.86 LOI 1.17 1.26 0.01 1.96 4.40

Its manufacturing method is implemented according to the following steps:

(1) Weigh 55% of slate, 30% of fly ash, 3% of magnesium metal slag, 10% of oil shale semi-coke, and 2% of dolomite according to mass percentage, and crush and grind the slate to 200 mesh, the metal magnesium slag, oil shale semi-coke and dolomite are ground to 200 mesh, and the above raw materials are mixed to obtain a mixture;

(2) Put the mixture into the intensive mixer, spray water on the mixture in the intensive mixer with a spraying device, roll into balls, and obtain wet pellets, wherein the wet pellets have a particle size less than 15 mm;

(3) drying the wet pellets naturally and then drying them in a rotary kiln to obtain dried pellets, wherein the drying temperature in the rotary kiln is 120°C;

(4) Place the dried pellets in a rotary kiln and roast for 1h-2.5h, wherein the roasting temperature is 1250°C and the roasting time is 8min;

(5) Cool the calcined balls to 75°C-125°C in the rotary kiln, and screen after leaving the kiln for natural cooling to obtain the finished product, wherein the particle size screening range of the finished product is 5-15mm.

With reference to the requirements of the experimental conditions of "Light Aggregate", the relevant properties of the product obtained in Example 4 were tested. The lightweight high-strength ceramsite obtained in Example 4 of the present invention has a bulk density of 638kg/m ³ , a water absorption rate of 6.5%, and a cylinder compressive strength of 8.1Mpa, meeting the national standard for lightweight high-strength ceramsite.

Example 6

Embodiment 6 of the present invention provides a kind of lightweight high-strength ceramsite with slate as raw material, and its raw material ratio according to mass percentage is:

In this embodiment 6, the light high-strength ceramsite with slate as raw material, the chemical composition and content of the raw material are shown in Table 10 below:

The raw material chemical composition and content (%) involved in table 10 embodiment 6

Its manufacturing method is implemented according to the following steps:

(1) Weigh 71% of slate, 15% of fly ash, 5% of magnesium metal slag, 5% of oil shale semi-coke, and 4% of dolomite according to mass percentage, and crush and grind the slate to 200 mesh, the metal magnesium slag, oil shale semi-coke and dolomite are ground to 200 mesh, and the above raw materials are mixed to obtain a mixture;

(2) Put the mixture into the intensive mixer, spray water on the mixture in the intensive mixer with a spraying device, roll into balls, and obtain wet pellets, wherein the wet pellets have a particle size less than 15 mm;

(3) drying the wet pellets naturally and then drying them in a rotary kiln to obtain dried pellets, wherein the drying temperature in the rotary kiln is 120°C;

(4) Place the dried pellets in a rotary kiln and roast for 1h-2.5h, wherein the roasting temperature is 1200°C and the roasting time is 8min;

(5) Cool the calcined balls to 75°C-125°C in the rotary kiln, and screen after leaving the kiln for natural cooling to obtain the finished product, wherein the particle size screening range of the finished product is 5-15mm.

With reference to the requirements of the experimental conditions of "Light Aggregate", the relevant performance of the product obtained in Example 6 was tested. The lightweight high-strength ceramsite obtained in Example 6 of the present invention has a bulk density of 735kg/m ³ , a water absorption rate of 5.9%, and a cylinder compressive strength of 7.2Mpa, reaching the national standard for lightweight high-strength ceramsite.

Example 7

Embodiment 7 of the present invention provides a kind of lightweight high-strength ceramsite with slate as raw material, and its raw material ratio according to mass percentage is:

In this embodiment 7, the light high-strength ceramsite with slate as raw material, the chemical composition and content of the raw material are shown in Table 11 below:

The raw material chemical composition and content (%) involved in table 11 embodiment 7

chemical composition slate fly ash Magnesium slag Oil Shale Semi-coke dolomite Total SiO₂ 61.36 2.28 0.82 1.46 65.92 Al₂O₃ 11.31 1.66 0.05 0.42 13.44 Fe₂O₃ 5.12 0.31 0.12 0.30 5.85 MgO 1.64 0.03 0.16 0.03 1.86 CaO 0.16 0.25 1.83 0.04 1.12 3.40 K₂O 2.87 0.07 0.00 0.08 3.02 Na₂O 1.91 0.02 0.00 0.03 1.96 P₂O₅ 0.04 0.03 0.00 0.02 0.09 MnO 1.64 0.00 0.00 0.00 1.64 TiO₂ 0.61 0.07 0.00 0.01 0.69 LOI 1.86 0.21 0.01 0.59 2.67

Its manufacturing method is implemented according to the following steps:

(1) Weigh 87% of slate, 5% of fly ash, 3% of magnesium metal slag, 3% of oil shale semi-coke, and 2% of dolomite according to mass percentage, and crush and grind the slate to 200 mesh, the metal magnesium slag, oil shale semi-coke and dolomite are ground to 200 mesh, and the above raw materials are mixed to obtain a mixture;

(2) Put the mixture into the intensive mixer, spray water on the mixture in the intensive mixer with a spraying device, roll into balls, and obtain wet pellets, wherein the wet pellets have a particle size less than 15 mm;

(3) drying the wet pellets naturally and then drying them in a rotary kiln to obtain dried pellets, wherein the drying temperature in the rotary kiln is 120°C;

(4) Place the dried pellets in a rotary kiln and roast for 1h-2.5h, wherein the roasting temperature is 1230°C and the roasting time is 5min;

(5) Cool the calcined balls to 75°C-125°C in the rotary kiln, and screen after leaving the kiln for natural cooling to obtain the finished product, wherein the particle size screening range of the finished product is 5-15mm.

With reference to the requirements of the experimental conditions of "Light Aggregate", the relevant performance of the product obtained in Example 7 was tested. The lightweight high-strength ceramsite obtained in Example 7 of the present invention has a bulk density of 805kg/m ³ , a water absorption rate of 5.5%, and a cylinder compressive strength of 6.4Mpa, meeting the national standard for lightweight high-strength ceramsite.

While preferred embodiments of the invention have been described, additional changes and modifications to these embodiments can be made by those skilled in the art once the basic inventive concept is appreciated. Therefore, it is intended that the appended claims be construed to cover the preferred embodiment as well as all changes and modifications which fall within the scope of the invention.

Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention also intends to include these modifications and variations.

Claims (8)

1. The light high-strength ceramsite prepared from slate is characterized by comprising the following raw materials in percentage by mass: 50-90% of slate, 5-30% of fly ash, 2-6% of metal magnesium slag, 1-10% of oil shale semi-coke and 1-4% of dolomite.

2. The light-weight high-strength ceramsite prepared from slate as claimed in claim 1, wherein the chemical composition of the slate comprises SiO₂，Al₂O₃，Fe₂O₃，MgO，CaO，K₂O，Na₂O，P₂O₅，MnO，TiO₂And LOI.

3. The lightweight high-strength ceramsite prepared from slate as raw material according to claim 1, wherein the magnesium slag comprises CaO and Al₂O₃，SiO₂，Fe₂O₃，Na₂O, MgO, F and K₂O。

4. The preparation method of the light-weight high-strength ceramsite prepared from slate as claimed in claim 1, which comprises the following steps:

(1) respectively weighing 50-90% of slate, 5-30% of fly ash, 2-6% of metal magnesium slag, 1-10% of oil shale semi-coke and 1-4% of dolomite according to the mass percentage, crushing and grinding the slate to 200-400 meshes, and uniformly mixing the raw materials to obtain a mixture;

(2) putting the mixture into a powerful mixer, spraying water on the mixture in the powerful mixer by using a spraying instrument, and rolling to form balls to obtain wet material balls;

(3) naturally drying the wet material balls, and then placing the wet material balls in a rotary kiln for drying to obtain dried material balls;

(4) placing the dried pellets in a rotary kiln to be roasted for 1-2.5 h;

(5) and cooling the roasted material balls to 75-125 ℃ in a rotary kiln, taking the material balls out of the kiln, naturally cooling and screening to obtain the finished product.

5. The method for preparing lightweight high-strength ceramsite by using slate as raw material according to claim 4, wherein the wet pellet size in the step (2) is less than 15 mm.

6. The method for preparing light-weight high-strength ceramsite by using slate as raw material according to claim 4, wherein the drying temperature in the rotary kiln in the step (3) is 80-200 ℃.

7. The method for preparing the light-weight high-strength ceramsite from the slates as the raw material according to claim 4, wherein the roasting temperature in the step (4) is 1200-1300 ℃, and the roasting time is 5-10 min.

8. The method for preparing light-weight high-strength ceramsite by using slates as raw materials according to claim 4, wherein in the step (5), the granularity screening range of the finished product is 5mm-15 mm.