Preparation method of low-ash impregnated and pressed carbon brick

Abstract

The invention belongs to the technical field of anticorrosive carbon brick processing, and particularly relates to a preparation method of a low-ash impregnated pressed carbon brick, which comprises the following steps: 1) pretreatment of ingredients: crushing, screening and grinding petroleum calcined coke to obtain coke sand with four particle sizes; 2) proportioning: proportioning the coke sand with four particle sizes according to a set proportion; 3) mixing and kneading: adding the proportionally prepared coke sand into a mixing and kneading pot, then adding the special brick-making resin, and sufficiently and uniformly mixing and kneading to obtain a raw material; 4) stirring: putting the raw material into a stirrer for stirring, and adding graphite powder for counterweight; (5) profiling: pressing the stirred raw materials into green bricks by using a press; and 6) curing, dipping and secondary curing: performing curing, dipping and secondary curing treatment on the green brick to obtain the finished product carbon brick. The raw materials are simple and easy to obtain, and the cost is low; the ash content in the finished carbon brick is 1t; the content is extremely low, the acid resistance is good, the performance is stable, and accidents are effectively reduced.

Description

Technical Field

[0001] The present invention belongs to the technical field of anti-corrosion carbon brick processing, and particularly relates to a preparation method of low-ash impregnated pressed carbon bricks. Background Art

[0002] Anti-corrosion carbon bricks have the advantages of good thermal stability and high mechanical strength, and have good inertness under both low-temperature and high-temperature reducing atmosphere conditions, and do not chemically react with acidic substances (except strong oxidizing acids). Therefore, they are widely used as lining anti-corrosion materials in reaction tanks, storage tanks in the phosphorus and fluorine chemical industries, bottom of blast furnaces, pickling tanks and electroplating tanks in the electroplating industry, dissolving tanks in the paper industry, autoclaves in the petrochemical industry, etc.

[0003] Traditional anti-corrosion carbon bricks are made from petroleum calcined coke, pitch coke, anthracite, coke and graphite as raw materials, and asphalt, tar and anthracene oil as binders. After extrusion molding, they are sintered in a reducing atmosphere (buried carbon, 1300 - 1450 °C × 20 h). However, traditional anti-corrosion carbon bricks have the following problems in the production process: the raw material sources are complex, the produced anti-corrosion carbon bricks have a low fixed carbon content and a high ash content, belonging to high-ash carbon bricks, and their performance is unstable. With the current development of the chemical industry towards large-scale and fine chemical industries, high-ash carbon bricks also have problems such as insufficient acid resistance and frequent accidents during use.

[0004] Therefore, the applicant considered improving the processing technology of existing anti-corrosion carbon bricks and designed a preparation method of low-ash impregnated pressed carbon bricks to solve the above problems. Summary of the Invention

[0005] In order to solve the above problems existing in the prior art, the present invention provides a preparation method of low-ash impregnated pressed carbon bricks, including the following steps:

[0006] 1) Pretreatment before batching: The petroleum calcined coke is crushed, screened and ground to obtain four kinds of coke sands with particle sizes of 0.075 mm, 0.075 - 0.5 mm, 0.5 - 1 mm and 1 - 2 mm.

[0007] 2) Batching: The coke sands with particle sizes of 0.075 mm, 0.075 - 0.5 mm, 0.5 - 1 mm and 1 - 2 mm are proportioned according to the ratio of 25 - 35%:20 - 25%:15 - 25%:30 - 40%.

[0008] 3) Kneading: The proportioned coke sands are added to a kneading pot, and then a special resin for brick making is added and kneaded evenly to obtain green stock.

[0009] 4) Stirring: The green stock is put into a stirrer for stirring, and graphite powder is added for weight balancing.

[0010] 5) Compression molding: Press the well-stirred green stock into brick blanks using a press.

[0011] 6) Curing, impregnation, and secondary curing: Obtain the finished carbon bricks after subjecting the brick blanks to curing, impregnation, and secondary curing treatments.

[0012] Specifically, the calcined petroleum coke in step 1) uses calcined petroleum coke with a carbon content of over 99.5%.

[0013] Specifically, in step 1), the calcined petroleum coke is divided into two parts. One part is processed by crushing and screening to obtain coke sands with three particle sizes of 0.075 - 0.5 mm, 0.5 - 1 mm, and 1 - 2 mm, and the other part is processed by grinding to obtain coke sands with a particle size of 0.075 mm.

[0014] Specifically, the special resin for brick making in step 3) uses liquid phenolic resin, and the addition ratio is 8 - 13%.

[0015] Specifically, in step 3), after kneading is completed, the green stock is divided into two parts. One part is roughly pressed using a rough press, and the other part is not processed.

[0016] Specifically, the press in step 5) uses a 630T electric screw press.

[0017] Specifically, in step 6), the curing temperature is 180 °C.

[0018] Specifically, in step 6), the impregnation treatment is to impregnate the brick blanks with resin under vacuum - pressure conditions.

[0019] The beneficial effects of the present invention are:

[0020] (1) The aggregate of the present invention only uses calcined petroleum coke with a carbon content of over 99.5% and graphite powder. The raw material sources are simple and easy to obtain, and the cost is relatively low.

[0021] (2) Adding graphite powder to the raw materials can improve the high - temperature resistance of the product carbon bricks, enhance the mechanical strength of the carbon bricks, improve the processing performance of the carbon bricks, and reduce the thermal expansion coefficient of the carbon bricks.

[0022] (3) The ash content in the finished carbon bricks is <1%, which is extremely low. When used in the large - scale chemical industry and fine chemical industry, it has good acid resistance, stable performance, and reduces the occurrence of accidents.

[0023] (4) The bulk density of the finished carbon bricks basically maintains within the range of 1.65 - 1.68 g / cm 3 The compressive strength basically maintains within the range of 70 - 75 MPa, and the flexural strength basically maintains within the range of 20 - 25 MPa, meeting the industry standards and having strong practicability. Description of the Drawings

[0024] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0025] Figure 1 It is a process flow chart of the present invention. DETAILED DESCRIPTION

[0026] The present invention is described clearly below in conjunction with the drawings and specific embodiments in the embodiments of the present invention. The description herein is only used to explain the present invention, but is not intended to limit the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work, any modifications, equivalent substitutions, improvements, etc., should be included in the protection scope of the present invention.

[0027] Example 1

[0028] The embodiment of the present invention provides a method for preparing low-ash impregnated pressed carbon bricks, wherein petroleum calcined coke with a carbon content of more than 99.5% is divided into two parts, one of which is crushed and screened to obtain coke sand with three particle sizes of 0.075-0.5mm, 0.5-1mm and 1-2mm, and the other part is ground to obtain coke sand with a particle size of 0.075mm; the coke sand with particle sizes of 0.075mm, 0.075-0.5mm, 0.5-1mm and 1-2mm is mixed in a ratio of 30%:25%:25%:20%. After the mixture is prepared, add the char sand into the kneading pot, and then add the liquid phenolic resin specially used for brick making, the adding ratio is 8-13%, mix and knead thoroughly and evenly to obtain the raw material. After the kneading is completed, divide the raw material into two parts, one part of which is roughly pressed by a rough press, and the other part is not processed; then put the raw material into the mixer for stirring, and add graphite powder as a weight; press the stirred raw material into a brick blank by an electric screw press; then cure the brick blank at 180°C, vacuum-pressure impregnate the resin and perform secondary curing treatment to obtain a low-ash impregnated pressed carbon brick 1.

[0029] Example 2

[0030] An embodiment of the present invention provides a method for preparing a low-ash impregnated pressed carbon brick. Petroleum calcined coke with a carbon content of more than 99.5% is divided into two parts. One part is subjected to crushing and screening to obtain coke sands with three particle sizes of 0.075 - 0.5 mm, 0.5 - 1 mm, and 1 - 2 mm, and the other part is subjected to grinding to obtain coke sand with a particle size of 0.075 mm; the coke sands with particle sizes of 0.075 mm, 0.075 - 0.5 mm, 0.5 - 1 mm, and 1 - 2 mm are proportioned according to 35%∶30%∶20%∶15%; after proportioning, the coke sand is added to a kneading pot, and then a liquid phenolic resin dedicated for brick making is added, with an addition ratio of 8 - 13%, and kneaded evenly to obtain green stock. After the kneading is completed, the green stock is divided into two parts, one part is roughly pressed by a rough press, and the other part is not processed; then the green stock is put into a mixer for stirring, and graphite powder is added for weight balancing; the stirred green stock is pressed into a brick blank by an electric screw press; then the brick blank is cured at 180°C, vacuum-pressure impregnated with resin, and subjected to secondary curing treatment to obtain a low-ash impregnated pressed carbon brick 2.

[0031] Example 3

[0032] An embodiment of the present invention provides a method for preparing a low-ash impregnated pressed carbon brick. Petroleum calcined coke with a carbon content of more than 99.5% is divided into two parts. One part is subjected to crushing and screening to obtain coke sands with three particle sizes of 0.075 - 0.5 mm, 0.5 - 1 mm, and 1 - 2 mm, and the other part is subjected to grinding to obtain coke sand with a particle size of 0.075 mm; the coke sands with particle sizes of 0.075 mm, 0.075 - 0.5 mm, 0.5 - 1 mm, and 1 - 2 mm are proportioned according to 32.5%∶27.5%∶22.5%∶17.5%; after proportioning, the coke sand is added to a kneading pot, and then a liquid phenolic resin dedicated for brick making is added, with an addition ratio of 8 - 13%, and kneaded evenly to obtain green stock. After the kneading is completed, the green stock is divided into two parts, one part is roughly pressed by a rough press, and the other part is not processed; then the green stock is put into a mixer for stirring, and graphite powder is added for weight balancing; the stirred green stock is pressed into a brick blank by an electric screw press; then the brick blank is cured at 180°C, vacuum-pressure impregnated with resin, and subjected to secondary curing treatment to obtain a low-ash impregnated pressed carbon brick 3.

[0033] The performance of traditional YZ-1 type anti-corrosion carbon bricks and YZ-2 type anti-corrosion carbon bricks is compared with the above low-ash impregnated pressed carbon bricks 1 - 3, and the results are shown in Table 1:

[0034]

[0035] Table 1

[0036] As can be seen from Table 1, the traditional anti-corrosion carbon bricks have relatively high ash content and apparent porosity, relatively low compressive and flexural strengths, and uneven bulk densities; while the low-ash impregnated pressed carbon bricks 1-3 of the present invention not only have low ash content and apparent porosity, but also good compressive and flexural strengths, and the bulk density basically maintains within the range of the upper and lower limits of 1.65-1.68 g / cm 3 , and all performances are superior to those of the traditional anti-corrosion carbon bricks, having strong practicability.

[0037] The embodiments of the present invention have been described above. The above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and variations are obvious to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments.

Claims

1. A preparation method of a low-ash impregnated pressed carbon brick, characterized in that: It includes the following steps: 1) Pretreatment of batching: After the petroleum calcined coke is crushed, screened and ground, coke sands with four particle sizes of 0.075mm, 0.075 - 0.5mm, 0.5 - 1mm and 1 - 2mm are obtained; 2) Batching: The coke sands with particle sizes of 0.075mm, 0.075 - 0.5mm, 0.5 - 1mm and 1 - 2mm are proportioned according to the ratio of 25 - 35%∶20 - 25%∶15 - 25%∶30 - 40%; 3) Kneading: The proportioned coke sands are added into a kneading pot, and then a special resin for brick making is added and kneaded evenly to obtain green stock; 4) Stirring: The green stock is put into a stirrer for stirring, and graphite powder is added for weight balancing; 5) Pressing: The stirred green stock is pressed into brick blanks by a press; 6) Curing, impregnation and secondary curing: The brick blanks are processed by curing, impregnation and secondary curing to obtain finished carbon bricks.

2. The preparation method according to claim 1, characterized in that: The petroleum calcined coke in step 1) uses petroleum calcined coke with a carbon content of more than 99.5%.

3. The preparation method according to claim 1, characterized in that: In step 1), the petroleum calcined coke is divided into two parts. One part is processed by crushing and screening to obtain coke sands with three particle sizes of 0.075 - 0.5mm, 0.5 - 1mm and 1 - 2mm, and the other part is processed by grinding to obtain coke sand with a particle size of 0.075mm.

4. The preparation method according to claim 1, characterized in that: The special resin for brick making in step 3) uses liquid phenolic resin, and the addition ratio is 8 - 13%.

5. The preparation method according to claim 1, characterized in that: In step 3), after kneading, the green stock is divided into two parts. One part is roughly pressed by a rough press, and the other part is not processed.

6. The preparation method according to claim 1, characterized in that: The press in step 5) uses a 630T electric screw press.

7. The preparation method according to claim 1, characterized in that: In step 6), the curing temperature is 180°C.

8. The preparation method according to claim 1, characterized in that: In step 6), the impregnation treatment is to impregnate the brick blanks with resin under vacuum - pressure conditions.

Images