CN114031344A

CN114031344A - Method for preparing baking-free pavement brick by using used refractory material erosion slag

Info

Publication number: CN114031344A
Application number: CN202111284704.2A
Authority: CN
Inventors: 吴小文; 沈灿; 张月娜; 黄朝晖; 刘艳改; 房明浩; 闵鑫; 米瑞宇
Original assignee: China University of Geosciences Beijing
Current assignee: China University of Geosciences Beijing
Priority date: 2021-11-01
Filing date: 2021-11-01
Publication date: 2022-02-11

Abstract

The invention discloses a method for preparing a baking-free pavement brick by using used refractory material erosion slag. The method specifically comprises the following steps: (1) and (3) pretreating the used refractory material erosion slag in a crusher and a vibration mill, and screening to obtain particles of 3-5mm, 1-3mm, 0.074-1 mm and 200 meshes. (2) Adding the erosion slag treated in the step (1) into cement and water according to different proportions, wherein the proportion is that the cement accounts for 10 wt% of the total mass fraction, and the water accounts for 2 wt% of the total mass fraction. (3) And (3) transferring the uniformly mixed powder in the step (2) into a round mold and a strip mold, performing compression molding on the powder under the molding pressure of 15MPa, maintaining the pressure for 1min, and demolding to obtain a final sample. (4) And (3) curing the baking-free brick sample at the normal temperature for 28 days, and spraying water every 3 days to prevent the baking-free brick from cracking. The baking-free brick prepared from the raw materials has the advantages of high strength, high hardness, simple production process, low cost and the like, and realizes the resource utilization of the solid waste of the refractory material erosion slag after use.

Description

Method for preparing baking-free pavement brick by using used refractory material erosion slag

Technical Field

The invention provides a method for preparing a baking-free pavement brick by using used refractory material erosion slag, and relates to the technical field of utilization of the whole amount of used refractory materials.

Background

The total quantity of steel produced in China is over 11 hundred million tons every year, and the materials make great contribution to the construction of the country. However, the erosion slag is used as waste in the production process, the annual output is over 4.8 hundred million tons, and the ecological environment is seriously influenced. The corrosion slag has low recovery rate due to the fact that the components contain heavy metals and are not suitable for long-distance transportation. With the continuous consumption of energy and the continuous exhaustion of natural resources in China, the development of new substitute resources becomes increasingly important. The utilization of the erosion slag as a baking-free brick is one of the main recycling ways at present. Compared with the sintered brick, the non-sintered brick has little pollution in the preparation process and relatively good working environment, so the steel slag has absolute advantages of reducing cost, saving resources and simplifying production process when being used as the non-sintered pavement brick.

The refractory material magnesia-alumina spinel brick is a high-quality refractory material which is artificially synthesized by using magnesia and alumina as raw materials. The material is sintered at a high temperature of more than 1800 ℃ in an ultrahigh temperature tunnel, so that the material has the advantages of large volume density, high mineral phase content, good crystal grain development, uniform structure and stable quality. The magnesia-alumina spinel has the characteristics of good erosion resistance, strong anti-stripping capability, good thermal stability, high temperature resistance and the like, and is widely used in refractory products such as bricks for high-temperature zones of converter kilns, ladle lining bricks, ladle castables and the like.

The method combines the national green development, energy conservation, emission reduction and clean production mode, and prepares the high-performance baking-free pavement brick meeting the national standard on the basis of utilizing the steel slag to the maximum extent after analyzing the components and the structure of the used refractory material erosion slag.

Disclosure of Invention

The embodiment of the invention aims to provide a comprehensive recycling technology of used refractory material erosion slag, which is used for solving the problem of resource recycling of the existing large low-order solid waste.

The baking-free pavement brick prepared from the erosion slag can fully solve the problem that a large amount of low-order solid waste is difficult to recycle. Meanwhile, the dosage of road materials and other cementing materials in China, such as ordinary portland cement, clay for roadbed, sand and stone and the like, can be obviously reduced, the pressure of shortage of raw materials is relieved, and the quality of road materials is improved.

Wherein the binding agent used for preparing the baking-free pavement brick is aqueous solution, and water accounts for 2 wt% of the total components.

The invention has the advantages that the used refractory material erosion slag is taken as the main raw material, thereby solving the technical problem of recycling the erosion slag, reducing the raw material cost and reducing the accumulation of solid wastes; meanwhile, the clay consumption is reduced, and the problem of land resource loss is solved. Adopts water as a bonding agent, has low price and is nontoxic and harmless. The preparation of the baking-free brick saves thermal resources. Therefore, the invention has the characteristics of rich raw materials, low production cost, simple process and environmental protection. The baking-free brick has high compressive strength.

Drawings

FIG. 1 is an XRD pattern of a post-consumer refractory erosion slag-based unfired pavement brick provided in example 8 of the present invention.

FIG. 2 is an SEM photograph of a used refractory-eroded slag-based baking-free paving brick provided in example 8 of the present invention

FIG. 3 is a diagram showing the ratio of compressive strength to raw materials of the baking-free pavement brick prepared under different raw material ratios.

FIG. 4 is a diagram showing the relationship between the flexural strength and the raw material ratio of the baking-free pavement brick prepared under different raw material ratios.

FIG. 5 is an XRD pattern of a post-consumer refractory-based unfired pavement brick provided in example 12 of the present invention.

Detailed Description

In order to make the objects, aspects and advantages of the present invention more apparent, the features of the present invention will be further described below with reference to examples, but not limited to only the following embodiments.

Example 1

Ball-milling the dried erosion slag for 2h, and screening to obtain four raw materials with the steel slag of 0-1, 1-3, 3-5mm and 200 meshes.

The chemical composition of the p.o4.5 cement is shown in table 1:

TABLE 1 chemical composition of P.O42.5 cement

Accurately weighing raw materials with certain mixture ratio and mass, corroding slag: 0-1 mm: 15 wt%, 1-3 mm: 35 wt%, 3-5 mm: 10 wt%, 200 mesh 30 wt%, cement: 10 wt%. Dry-mixing the dry materials for 5min, adding water, and stirring for 5min until the raw materials are uniformly mixed, wherein the water is used in an amount of 2 wt%.

And (3) placing the injection-molded die into a small tablet press, and controlling the pressure to be 15 MPa. During the pressing process, the sample continues to harden to achieve the desired primary strength. The samples that completed pressing were subjected to a mold release treatment.

And (5) placing the demoulded sample in a ventilated and dried place for curing. The curing method is that the mixture is kept still for 28 days under the conditions of normal temperature and normal pressure, and then the mixture is sprinkled with water for natural curing, wherein the sprinkling frequency is that the water is sprinkled every three days. And naturally curing for 28 days to obtain the prepared baking-free pavement brick.

And (3) carrying out performance test on the used refractory material-based baking-free pavement brick: the compressive strength is 7.71 MPa.

SEM pictures of the erosion slag-based baking-free type pavior brick samples are shown in figure 1: as can be seen from FIG. 1, the sample has a plate-shaped structure and a few pores, and gypsum, quartz, ettringite and the like in the final sample are filled with each other to form a compact structure, so that the sample prepared by the experimental method has high strength.

Example 2

The material screening was performed as in example 1.

Accurately weighing raw materials with certain mixture ratio and mass, corroding slag: 0-1 mm: 20 wt%, 1-3 mm: 30 wt%, 3-5 mm: 10 wt%, 200 mesh: 30 wt%, cement: 10 wt%. Dry-mixing the dry materials for 5min, adding water, and stirring for 5min until the raw materials are uniformly mixed, wherein the water is used in an amount of 2 wt%.

And (3) carrying out performance test on the used refractory material-based baking-free pavement brick: the compressive strength is 8.76 MPa.

Example 3

The material screening was performed as in example 1.

Accurately weighing raw materials with certain mixture ratio and mass, corroding slag: 0-1 mm: 25 wt%, 1-3 mm: 25 wt%, 3-5 mm: 10 wt%, 200 mesh: 20 wt%, cement: 10 wt%. Dry-mixing the dry materials for 5min, adding water, and stirring for 5min until the raw materials are uniformly mixed, wherein the water is used in an amount of 2 wt%.

And (3) carrying out performance test on the used refractory material-based baking-free pavement brick: the compressive strength is 8.64 MPa.

Example 4

The material screening was performed as in example 1.

Accurately weighing raw materials with certain mixture ratio and mass, corroding slag: 0-1 mm: 30 wt%, 1-3 mm: 20 wt%, 3-5 mm: 10 wt%, 200 mesh: 30 wt%, cement: 10 wt%. Dry-mixing the dry materials for 5min, adding water, and stirring for 5min until the raw materials are uniformly mixed, wherein the water is used in an amount of 2 wt%.

And (3) carrying out performance test on the used refractory material-based baking-free pavement brick: the compressive strength is 7.16 MPa.

Example 5

The material screening was performed as in example 1.

Accurately weighing raw materials with certain mixture ratio and mass, corroding slag: 0-1 mm: 35 wt%, 1-3 mm: 15 wt%, 3-5 mm: 10 wt%, 200 mesh: 30 wt%, cement: 10 wt%. Dry-mixing the dry materials for 5min, adding water, and stirring for 5min until the raw materials are uniformly mixed, wherein the water is used in an amount of 2 wt%.

And (3) carrying out performance test on the used refractory material-based baking-free pavement brick: the compressive strength is 8.58 MPa.

Example 6

The material screening was performed as in example 1.

Accurately weighing raw materials with certain mixture ratio and mass, corroding slag: 0-1 mm: 15 wt%, 1-3 mm: 25 wt%, 3-5 mm: 20 wt%, 200 mesh: 30 wt%, cement: 10 wt%. Dry-mixing the dry materials for 5min, adding water, and stirring for 5min until the raw materials are uniformly mixed, wherein the water is used in an amount of 2 wt%.

And (3) carrying out performance test on the used refractory material-based baking-free pavement brick: the compressive strength is 8.33 MPa.

Example 7

The material screening was performed as in example 1.

Accurately weighing raw materials with certain mixture ratio and mass, corroding slag: 0-1 mm: 20 wt%, 1-3 mm: 20 wt%, 3-5 mm: 20 wt%, 200 mesh: 30 wt%, cement: 10 wt%. Dry-mixing the dry materials for 5min, adding water, and stirring for 5min until the raw materials are uniformly mixed, wherein the water is used in an amount of 2 wt%.

And (3) carrying out performance test on the used refractory material-based baking-free pavement brick: the compressive strength is 7.03 MPa.

Example 8

The material screening was performed as in example 1.

Accurately weighing raw materials with certain mixture ratio and mass, corroding slag: 0-1 mm: 25 wt%, 1-3 mm: 15 wt%, 3-5 mm: 20 wt%, 200 mesh: 30 wt%, cement: 10 wt%. Dry-mixing the dry materials for 5min, adding water, and stirring for 5min until the raw materials are uniformly mixed, wherein the water is used in an amount of 2 wt%.

And (3) carrying out performance test on the used refractory material-based baking-free pavement brick: the compressive strength is 8.73 MPa.

Example 9

The material screening was performed as in example 1.

Accurately weighing raw materials with certain mixture ratio and mass, corroding slag: 0-1 mm: 15 wt%, 1-3 mm: 15 wt%, 3-5 mm: 30 wt%, 200 mesh: 30 wt%, cement: 10 wt%. Dry-mixing the dry materials for 5min, adding water, and stirring for 5min until the raw materials are uniformly mixed, wherein the water is used in an amount of 2 wt%.

And (3) carrying out performance test on the used refractory material-based baking-free pavement brick: the compressive strength is 9.57 MPa.

Example 10

The material screening was performed as in example 1.

Accurately weighing raw materials with certain mixture ratio and mass, corroding slag: 0-1 mm: 25 wt%, 1-3 mm: 35 wt%, 3-5 mm: 10 wt%, 200 mesh: 20 wt%, cement: 10 wt%. Dry-mixing the dry materials for 5min, adding water, and stirring for 5min until the raw materials are uniformly mixed, wherein the water is used in an amount of 2 wt%.

Example 11

The material screening was performed as in example 1.

And (3) carrying out performance test on the used refractory material-based baking-free pavement brick: the compressive strength is 8.22 MPa.

Example 12

The material screening was performed as in example 1.

Accurately weighing raw materials with certain mixture ratio and mass, corroding slag: 0-1 mm: 25 wt%, 1-3 mm: 15 wt%, 3-5 mm: 30 wt%, 200 mesh: 20 wt%, cement: 10 wt%. Dry-mixing the dry materials for 5min, adding water, and stirring for 5min until the raw materials are uniformly mixed, wherein the water is used in an amount of 2 wt%.

And (3) carrying out performance test on the used refractory material-based baking-free pavement brick: the compressive strength is 9.17 MPa.

Claims

1. A method for preparing a baking-free pavement brick by using used refractory material erosion slag is characterized by comprising the following steps: the method comprises the following steps:

(1) the pre-treatment of the raw materials is carried out,

and (3) putting the used refractory material erosion slag into a jaw crusher to be crushed for 30-60 s, and screening to obtain particles with the particle size of more than 5mm, 3-5mm, 1-3mm and 0.074-1 mm. And (3) placing large particles with the particle size of more than 5mm into a vibration mill, performing vibration grinding for 15-30 s, and then placing the large particles into a ball mill to perform ball milling for 1-2 h to obtain particles with the particle size of less than 200 meshes. The raw materials are high-quality powder materials which are crushed and sieved;

(2) compounding and compounding

Mixing the raw materials pretreated in the step (1) with auxiliary material cement, uniformly mixing the raw materials and the auxiliary material cement in a dry mode, and then adding water to carry out wet mixing to obtain a mixture;

(3) shaping and preparation

Dry pressing and forming: before the mold is used, the rust-preventive oil is removed and the mold is cleaned by absolute ethyl alcohol. And then injecting the mixture into a die, and maintaining the pressure for 1min by using a powder tablet press under 15MPa and demoulding to obtain cylindrical and strip-shaped samples. And naturally cooling to normal temperature, and curing for 28 days at normal temperature and normal pressure to obtain the prepared erosion slag-based baking-free pavement brick.

2. The method of claim 1, wherein: in the step (1), the first step of the method,

the pretreatment sequentially comprises drying, ball milling and screening; the used refractory material erosion slag obtained after pretreatment in the step (1) is screened into three specifications of 0-1mm, 1-3mm and 3-5 mm; as the raw materials of the erosion slag with the thickness of 1-3mm and 3-5mm can be used as the framework of the baking-free brick, the natural sand is not added as the aggregate of the baking-free brick.

3. The method of claim 1, wherein: the raw material of the erosion slag comprises a plurality of components, such as CaO, Fe2O3, and small amount of SiO2, MnO, MgO, etc.; the erosion slag raw material comprises the following components in percentage by weight: 9.19 wt% of SiO2, 3.63 wt% of MnO, 30.5 wt% of Fe2O3, 1-5 wt% of MgO and 48.5 wt% of CaO.

4. The method of claim 1, wherein: in the step (2), the auxiliary materials comprise cement and water.

5. The production method according to one of claims 1 to 5, characterized in that: in the raw materials and the auxiliary materials, the weight ratio of each component is as follows:

the mass of the sample prepared was 20g and the amount of water was 2 wt% based on the size of the sample that could be molded with the mold.

6. The method of claim 1, wherein: the step (3) comprises the following substeps:

step 3-1, coating a layer of engine oil on the surface of the die;

step 3-2, injecting the mixture into a mold;

3-3, putting the injection molded die into a tabletting machine for pressing;

step 3-4, demoulding to obtain the sample;

preferably, in step 3-3, the press forming is performed at a press pressure of 15MPa, with a holding pressure of 1 minute.

7. The method of claim 1, wherein: in step 4, the curing is performed as follows: and (4) placing the demolded sample in a ventilated place for drying, standing for 28 days, and watering every three days for maintenance. More preferably, the flexural strength of the pavement brick is 2.31-4.86 MPa.