A refractory material for hazardous waste incineration rotary kiln and its preparation method

Abstract

The present invention relates to a refractory material for a hazardous waste incineration rotary kiln and a preparation method thereof. The refractory material for a hazardous waste incineration rotary kiln comprises the following substances in parts by weight: 50-60% of acid-modified geopolymer, 15-20% of silicon nitride, 9-13% of fused chromium corundum, 8-12% of zirconium corundum, 0.08-0.1% of explosion-proof fiber, 1-2% of binder and 3.9-4.5% of water. The refractory material for a hazardous waste incineration rotary kiln has low porosity and good fire resistance and corrosion resistance.

Description

Technical Field

[0001] The invention belongs to the technical field of refractory materials, and in particular relates to a refractory material for a hazardous waste incineration rotary kiln and a preparation method thereof. Background Art

[0002] The hazardous waste incineration rotary kiln has a wide range of material applicability and can simultaneously process solid, liquid and gas hazardous wastes at a temperature of about 1200°C. The working conditions during the incineration of hazardous wastes are complex, and there are acid corrosion and alkali corrosion. Therefore, the hazardous waste incineration rotary kiln must have good acid and alkali resistance and high temperature resistance. In addition, fluorine-containing, potassium-sodium-containing components and some low-melting-point materials are particularly prone to corrosion of refractory materials.

[0003] In the prior art, corundum mullite, corundum, corundum silicon carbide and chrome corundum are generally used to prepare castables for the lining of hazardous waste incineration rotary kilns. These materials often have pores after casting, and acidic gases or alkaline liquids can easily penetrate and corrode the lining of the hazardous waste incineration rotary kiln. The invention patent with application publication number CN116253573A discloses a corundum-zirconium mullite castable for hazardous waste furnaces. The raw material formula is calculated by weight: 8-5mm waste porcelain 5-8 parts, 5-10 parts of waste porcelain 5-3mm, 15-40 parts of fused corundum 3-1mm, 8-22 parts of plate-shaped corundum 0.088-0.044mm, 15-30 parts of fused zirconium mullite 1-0.01mm, 5-20 parts of fused zirconium mullite 0.088-0.044mm, 8-15 parts of high-efficiency enhancer, 3-15 parts of anti-corrosion ingredients, 1-1.5 parts of mullite fiber, 3-5 parts of CA75 cement, and water.

[0004] The hazardous waste furnace uses corundum-zirconium mullite castable material, which has pores after casting, which will lead to a short service life of the lining of the hazardous waste incineration rotary kiln. Summary of the invention

[0005] The purpose of the present invention is to provide a refractory material for a hazardous waste incineration rotary kiln, which has good corrosion resistance and high temperature resistance.

[0006] Another object of the present invention is to provide a method for preparing refractory materials for hazardous waste incineration rotary kiln.

[0007] In order to achieve the above purpose, the technical solution adopted by the present invention is:

[0008] A refractory material for a hazardous waste incineration rotary kiln comprises the following substances in mass fractions: 50-60% of acid-modified geopolymer, 15-20% of silicon nitride, 9-13% of fused chromium corundum, 8-12% of zirconium corundum, 0.08-0.1% of explosion-proof fiber, 1-2% of binder and 3.9-4.5% of water.

[0009] Furthermore, the preparation method of the acid-modified geopolymer includes the following steps: Sialon combined with silicon carbide and alumina are mixed evenly to obtain a solid mixture, and then the solid mixture is mixed and stirred evenly with a phosphoric acid solution and then cured until a solid acid-modified geopolymer is obtained, and the solid acid-modified geopolymer is dried and then crushed.

[0010] Furthermore, the mass ratio of the Sialon-bonded silicon carbide to alumina is 1.5 to 2:1.

[0011] Furthermore, the mass ratio of the solid mixture to the phosphoric acid solution is 1:1.3 to 1:1.5, and the mass concentration of the phosphoric acid solution is 30 to 40 g.mL -1 .

[0012] Furthermore, the curing time is 24 to 36 hours, the curing temperature is 50 to 60° C., the drying temperature is 30 to 35° C., and the drying time is 3 to 5 hours.

[0013] Furthermore, the particle size of the acid-modified polymer is 3 to 1 mm.

[0014] Furthermore, the particle size of the silicon nitride is 1 to 0.01 mm.

[0015] Furthermore, the particle size of the fused chromium corundum is less than or equal to 1 mm, and the particle size of the zirconium corundum is 200 mesh.

[0016] Furthermore, the binder is Seka 71 cement, pure calcium aluminate cement or hydrated alumina.

[0017] The preparation method of refractory materials for hazardous waste incineration rotary kiln comprises the following steps: placing a formulated amount of acid-modified geopolymer, silicon nitride, fused chromium corundum, zirconium corundum, explosion-proof fiber and water in a premixer, premixing for 5 to 7 minutes, then adding a binder, and continuing to mix for 8 to 10 minutes.

[0018] Beneficial effects of the present invention:

[0019] The refractory material for the hazardous waste incineration rotary kiln of the present invention contains an acid-modified geopolymer which is a combination product of silicon and aluminum compounds, and has a tetrahedral structure formed inside, has high compressive strength, and has good acid and alkali corrosion resistance and high temperature resistance. The acid-modified geopolymer will expand slightly when heated, fill the pores of the refractory material, and reduce the porosity. In addition, the acid-modified geopolymer and silicon nitride cooperate with each other to form a dense structure, which has good high temperature resistance and acid and alkali corrosion resistance. The binder and silicon nitride have a synergistic effect, and can bond the various substances together to improve the strength. DETAILED DESCRIPTION

[0020] The present invention will be further described below in conjunction with the embodiments of the present invention.

[0021] Example 1

[0022] The refractory material for the hazardous waste incineration rotary kiln of this embodiment includes the following substances: 60 kg of acid-modified geopolymer, 18 kg of silicon nitride, 13 kg of fused chrome corundum, 10 kg of zirconium corundum, 0.09 kg of explosion-proof fiber, 1.5 kg of binder, and 4 kg of water. The particle size of the acid-modified geopolymer is 3 to 1 mm. The particle size of silicon nitride is 1 to 0.01 mm. The particle size of the fused chrome corundum is less than or equal to 1 mm, and the particle size of the zirconium corundum is 200 mesh. The binder is pure calcium aluminate cement.

[0023] The preparation method of the acid-modified geopolymer includes the following steps: taking 1.5 kg of Sialon combined with silicon carbide and 1 kg of alumina and mixing them evenly to obtain a solid mixture, then mixing the solid mixture with a phosphoric acid solution and stirring them evenly and curing them until a solid acid-modified geopolymer is obtained, and then drying and crushing the solid acid-modified geopolymer. The mass ratio of the solid mixture to the phosphoric acid solution is 1:1.3, and the mass concentration of the phosphoric acid solution is 30 g.mL -1 .

[0024] The preparation method of refractory material for hazardous waste incineration rotary kiln comprises the following steps: placing the formulated amount of acid-modified geopolymer, silicon nitride, fused chromium corundum, zirconium corundum, explosion-proof fiber and binder in a premixer, premixing for 5 minutes, then adding water, and continuing to mix for 5 minutes.

[0025] Example 2

[0026] The refractory material for the hazardous waste incineration rotary kiln of this embodiment includes the following substances: 55 kg of acid-modified geopolymer, 20 kg of silicon nitride, 10 kg of fused chrome corundum, 12 kg of zirconium corundum, 0.1 kg of explosion-proof fiber, 1.5 kg of binder, and 4.2 kg of water. The particle size of the acid-modified geopolymer is 3 to 1 mm. The particle size of silicon nitride is 1 to 0.01 mm. The particle size of the fused chrome corundum is less than or equal to 1 mm, and the particle size of the zirconium corundum is 200 mesh. The binder is hydrated alumina.

[0027] The preparation method of the acid-modified geopolymer includes the following steps: taking 1.5 kg of Sialon combined with silicon carbide and 1 kg of alumina and mixing them evenly to obtain a solid mixture, then mixing the solid mixture with a phosphoric acid solution and stirring them evenly and curing them until a solid acid-modified geopolymer is obtained, and then drying and crushing the solid acid-modified geopolymer. The mass ratio of the solid mixture to the phosphoric acid solution is 1:1.5, and the mass concentration of the phosphoric acid solution is 34 g.mL -1 .

[0028] The preparation method of refractory material for hazardous waste incineration rotary kiln comprises the following steps: placing the formulated amount of acid-modified geopolymer, silicon nitride, fused chromium corundum, zirconium corundum, explosion-proof fiber and binder in a premixer, premixing for 5 minutes, then adding water, and continuing to mix for 5 minutes.

[0029] Example 3

[0030] The refractory material for the hazardous waste incineration rotary kiln of this embodiment includes the following substances: 50 kg of acid-modified geopolymer, 15 kg of silicon nitride, 13 kg of fused chrome corundum, 8 kg of zirconium corundum, 0.8 kg of explosion-proof fiber, 2 kg of binder, and 3.9 kg of water. The particle size of the acid-modified geopolymer is 3 to 1 mm. The particle size of silicon nitride is 1 to 0.01 mm. The particle size of the fused chrome corundum is less than or equal to 1 mm, and the particle size of the zirconium corundum is 200 mesh. The binder is hydrated alumina.

[0031] The preparation method of the acid-modified geopolymer includes the following steps: taking 1.5 kg of Sialon combined with silicon carbide and 1 kg of alumina and mixing them evenly to obtain a solid mixture, then mixing the solid mixture with a phosphoric acid solution and stirring them evenly and curing them until a solid acid-modified geopolymer is obtained, and then drying and crushing the solid acid-modified geopolymer. The mass ratio of the solid mixture to the phosphoric acid solution is 1:1.4, and the mass concentration of the phosphoric acid solution is 40 g.mL -1 .

[0032] The preparation method of refractory material for hazardous waste incineration rotary kiln comprises the following steps: placing the formulated amount of acid-modified geopolymer, silicon nitride, fused chromium corundum, zirconium corundum, explosion-proof fiber and binder in a premixer, premixing for 5 minutes, then adding water, and continuing to mix for 5 minutes.

[0033] Example 4

[0034] The refractory material for the hazardous waste incineration rotary kiln of this embodiment includes the following substances: 60 kg of acid-modified geopolymer, 20 kg of silicon nitride, 9 kg of fused chrome corundum, 10 kg of zirconium corundum, 0.8 kg of explosion-proof fiber, 1.5 kg of binder, and 4.5 kg of water. The particle size of the acid-modified geopolymer is 3 to 1 mm. The particle size of silicon nitride is 1 to 0.01 mm. The particle size of the fused chrome corundum is less than or equal to 1 mm, and the particle size of the zirconium corundum is 200 mesh. The binder is Seka 71 cement.

[0035] The preparation method of the acid-modified geopolymer includes the following steps: taking 1.5 kg of Sialon combined with silicon carbide and 1 kg of alumina and mixing them evenly to obtain a solid mixture, then mixing the solid mixture with a phosphoric acid solution and stirring them evenly and curing them until a solid acid-modified geopolymer is obtained, and then drying and crushing the solid acid-modified geopolymer. The mass ratio of the solid mixture to the phosphoric acid solution is 1:1.5, and the mass concentration of the phosphoric acid solution is 40 g.mL-1 .

[0036] The preparation method of refractory material for hazardous waste incineration rotary kiln comprises the following steps: placing the formulated amount of acid-modified geopolymer, silicon nitride, fused chromium corundum, zirconium corundum, explosion-proof fiber and binder in a premixer, premixing for 5 minutes, then adding water, and continuing to mix for 5 minutes.

[0037] Example 5

[0038] The refractory material for the hazardous waste incineration rotary kiln of this embodiment includes the following substances: 50 kg of acid-modified geopolymer, 16 kg of silicon nitride, 12 kg of fused chrome corundum, 8 kg of zirconium corundum, 0.1 kg of explosion-proof fiber, 1.5 kg of binder, and 4 kg of water. The particle size of the acid-modified geopolymer is 3 to 1 mm. The particle size of silicon nitride is 1 to 0.01 mm. The particle size of the fused chrome corundum is less than or equal to 1 mm, and the particle size of the zirconium corundum is 200 mesh. The binder is Seka 71 cement.

[0039] The preparation method of the acid-modified geopolymer includes the following steps: taking 1.5 kg of Sialon combined with silicon carbide and 1 kg of alumina and mixing them evenly to obtain a solid mixture, then mixing the solid mixture with a phosphoric acid solution and stirring them evenly and curing them until a solid acid-modified geopolymer is obtained, and then drying and crushing the solid acid-modified geopolymer. The mass ratio of the solid mixture to the phosphoric acid solution is 1:1.3, and the mass concentration of the phosphoric acid solution is 35 g.mL -1 .

[0040] The preparation method of refractory material for hazardous waste incineration rotary kiln comprises the following steps: placing the formulated amount of acid-modified geopolymer, silicon nitride, fused chromium corundum, zirconium corundum, explosion-proof fiber and binder in a premixer, premixing for 5 minutes, then adding water, and continuing to mix for 5 minutes.

[0041] Comparative Example 1

[0042] The refractory material for hazardous waste incineration rotary kiln in this comparative example contains substantially the same raw materials as those in Example 1, except that fused chromium corundum is used instead of acid-modified geopolymer, that is, the refractory material for hazardous waste incineration rotary kiln in this comparative example includes the following substances: 18 kg of silicon nitride, 73 kg of fused chromium corundum, 10 kg of zirconium corundum, 0.09 kg of explosion-proof fiber, 1.5 kg of binder and 4 kg of water.

[0043] Comparative Example 2

[0044] The refractory material for hazardous waste incineration rotary kiln in this comparative example contains substantially the same raw materials as those in Example 1, except that fused chrome corundum is used to replace part of the acid-modified geopolymer, that is, the refractory material for hazardous waste incineration rotary kiln in this comparative example includes the following substances: 30 kg of acid-modified geopolymer, 18 kg of silicon nitride, 43 kg of fused chrome corundum, 10 kg of zirconium corundum, 0.09 kg of explosion-proof fiber, 1.5 kg of binder and 4 kg of water.

[0045] Comparative Example 3

[0046] The refractory material for hazardous waste incineration rotary kiln in this comparative example contains substantially the same raw materials as those in Example 1, except that fused chromium corundum is used instead of silicon nitride, that is, the refractory material for hazardous waste incineration rotary kiln in this comparative example includes the following substances: 60 kg of acid-modified geopolymer, 31 kg of fused chromium corundum, 10 kg of zirconium corundum, 0.09 kg of explosion-proof fiber, 1.5 kg of binder and 4 kg of water.

[0047] Comparative Example 4

[0048] The refractory material for hazardous waste incineration rotary kiln in this comparative example contains substantially the same raw materials as those in Example 1, except that the preparation method of the acid-modified geopolymer is different from that in Example 1, that is, the refractory material for hazardous waste incineration rotary kiln in this comparative example includes the following substances: 60 kg of acid-modified geopolymer, 18 kg of silicon nitride, 13 kg of fused chromium corundum, 10 kg of zirconium corundum, 0.09 kg of explosion-proof fiber, 1.5 kg of binder and 4 kg of water. The preparation method of the acid-modified geopolymer includes the following steps: take 2.5 kg of kaolin, then mix and stir the kaolin with phosphoric acid solution, and then cure until it becomes a solid acid-modified geopolymer, and then dry and crush the solid acid-modified geopolymer. The mass ratio of kaolin to phosphoric acid solution is 1:1.3, and the mass concentration of the phosphoric acid solution is 30 g.mL -1 .

[0049] Test example

[0050] 1. Determination of bulk density

[0051] The bulk density of the refractory materials for hazardous waste incineration rotary kiln of Examples 1 to 5 and Comparative Examples 1 to 4 after treatment at 110° C. for 24 hours was measured with reference to the method of YB / T5200-1993. The results are shown in Table 1.

[0052] 2. Determination of compressive strength at room temperature

[0053] The room temperature compressive strength of the refractory materials for hazardous waste incineration rotary kiln of Examples 1 to 5 and Comparative Examples 1 to 4 after treatment at 1200° C. for 3 hours was measured with reference to the method of GB / T5072-2008. The results are shown in Table 1.

[0054] 3. Determination of corrosion resistance

[0055] According to the GB / T8931-2007 method, the refractory materials for hazardous waste incineration rotary kiln of Examples 1 to 5 and Comparative Examples 1 to 4 were tested for slag corrosion resistance. The samples of fluorine-containing organic waste liquid and waste liquid containing potassium and sodium components were alternately eroded, and then baked in an oven at 110°C for 24 hours, and then placed in a high-temperature reburning furnace at 1200°C for 3 hours. The corrosion conditions were tested, and the test results are shown in Table 1.

[0056] 4. Determine the change of permanent line during heating

[0057] The heating permanent line changes of the refractory materials used in the hazardous waste incineration rotary kiln of Examples 1 to 5 and Comparative Examples 1 to 4 after being treated at 1200° C. for 3 hours were measured with reference to the method of GB / T5988-2007. The results are shown in Table 1.

[0058] It can be seen from Table 1 that when the acid-modified geopolymer content is high, the refractory material has good slag erosion resistance. When the acid-modified geopolymer is replaced by fused chrome corundum, the corrosion resistance is poor, and when the acid-modified geopolymer is prepared, the erosion resistance and high temperature resistance of the refractory material are also reduced by using metakaolin instead of sialon combined with silicon carbide and alumina.

[0059] Table 1 Refractory properties of hazardous waste incineration rotary kiln in Example 1-Example 5 and Comparative Example 1-Comparative Example 4

[0060]

Claims

1. A refractory material for a hazardous waste incineration rotary kiln, characterized in that: The invention comprises the following substances in mass fractions: 50-60% acid-modified geopolymer, 15-20% silicon nitride, 9-13% fused chromium corundum, 8-12% zirconium corundum, 0.08-0.1% explosion-proof fiber, 1-2% binder and 3.9-4.5% water; the preparation method of the acid-modified geopolymer comprises the following steps: The Sialon combined with silicon carbide and alumina are mixed evenly to obtain a solid mixture, and then the solid mixture is mixed and stirred evenly with a phosphoric acid solution and cured until a solid acid-modified geopolymer is obtained. The solid acid-modified geopolymer is dried and then crushed; the mass ratio of the Sialon combined with silicon carbide and alumina is 1.5 to 2:1; the mass ratio of the solid mixture to the phosphoric acid solution is 1:1.3 to 1:1.5, and the mass concentration of the phosphoric acid solution is 30 to 40 g.mL -1 .

2. The refractory material for hazardous waste incineration rotary kiln according to claim 1, characterized in that: The curing time is 24 to 36 hours, the curing temperature is 50 to 60° C., the drying temperature is 30 to 35° C., and the drying time is 3 to 5 hours.

3. The refractory material for hazardous waste incineration rotary kiln according to claim 1, characterized in that: The particle size of the acid-modified polymer is 3 to 1 mm.

4. The refractory material for hazardous waste incineration rotary kiln according to claim 1, characterized in that: The particle size of the silicon nitride is 1 to 0.01 mm.

5. The refractory material for hazardous waste incineration rotary kiln according to claim 1, characterized in that: The particle size of the fused chromium corundum is less than or equal to 1 mm, and the particle size of the zirconium corundum is 200 mesh.

6. The refractory material for hazardous waste incineration rotary kiln according to claim 1, characterized in that: The binder is Seka 71 cement, pure calcium aluminate cement or hydrated alumina.

7. The method for preparing a refractory material for a hazardous waste incineration rotary kiln according to claim 1, characterized in that: The method comprises the following steps: placing the formulated amount of acid-modified geopolymer, silicon nitride, fused chromium corundum, zirconium corundum, explosion-proof fiber and water in a premixer, premixing for 5 to 7 minutes, then adding a binder, and continuing to mix for 5 to 7 minutes to obtain the product.

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