CN110734270A

CN110734270A - kinds of red mud baked bricks and preparation method thereof

Info

Publication number: CN110734270A
Application number: CN201911111135.4A
Authority: CN
Inventors: 康俊峰; 尹立卿; 岳云龙; 李安健; 李升�; 安越
Original assignee: University of Jinan
Current assignee: University of Jinan
Priority date: 2019-11-14
Filing date: 2019-11-14
Publication date: 2020-01-31

Abstract

The invention discloses baked bricks prepared by taking red mud and waste glass as main raw materials, which are prepared from, by mass, 50-90wt% of red mud, 6-50wt% of waste glass and 5-25wt% of a binder, wherein the baked bricks are prepared by uniformly mixing, pressing, molding and sintering for cooling, and the red mud baked bricks have the following properties of compressive strength of 20-40MPa and flexural strength of 7-13MPa, and have the characteristics of , full utilization of red mud waste and reduction of harm to the environment, and have the characteristics of low price, stable chemical properties, high compressive and flexural strength and simple preparation process, and can meet requirements of pushing and using conditions and solve the problem of red mud pollution.

Description

kinds of red mud baked bricks and preparation method thereof

Technical Field

The invention relates to a preparation method of red mud baked bricks, belonging to the field of manufacturing methods of baked bricks.

Background

The red mud is industrial waste generated in the process of producing aluminum, the total amount of the red mud generated in the world every year is about 0.7-1.2 hundred million tons at present, China is taken as the fourth alumina producing country, th alumina plant is built since 1945, with the vigorous development of the aluminum industry, the discharge amount of the red mud in China is increased day by day, more than 5000 ten thousand of the red mud discharged up to now is discharged every year, but the comprehensive utilization rate of the red mud is only 4%, so that a large amount of red mud can only be treated by a yard stacking method and occupies a large amount of land resources, and because the red mud contains a large amount of alkali, heavy metal and other potential pollutants, the red mud causes great harm to the land and directly or indirectly harms the health of people.

The glass products are widely used in industrial production and daily life, huge demand promotes the vigorous development of the glass industry, and a great amount of glass waste is generated, the amount of waste glass generated in China is about 1000 million tons each year, and accounts for about 5% of the total amount of solid waste, and the recycling of the waste glass is also huge problems due to different models produced by manufacturers

With the rapid development of the building industry, about 7500 million baked bricks (converted into standard bricks) are consumed in China every year, and if a large number of baked bricks are all prepared by clay, a large number of fertile farmlands can be damaged, so that the government of China repeatedly proposes that clay solid baked bricks are prohibited from being produced and used, and encourages to use various industrial waste residues for making bricks so as to protect the clay and arable land which is dependent on survival.

Disclosure of Invention

Aiming at the problem of low comprehensive utilization rate of red mud, the invention provides preparation methods for preparing sintered bricks by using red mud, wherein the method takes red mud and waste glass as main raw materials, greatly improves the comprehensive utilization rate of solid wastes, and in addition, the sintered bricks in the patent have the characteristics of fewer raw material types, simple preparation process and low cost.

The red mud baked brick and the preparation process comprise the following steps:

(1) carrying out high-temperature sintering pretreatment on the red mud, putting the red mud into a 400-plus-700 ℃ high-temperature furnace for heat preservation for 1-3h, and sieving the red mud by a 200-mesh sieve;

(2) the ingredients are as follows by mass percent: 50-90wt% of red mud, 6-50wt% of waste glass and 5-25wt% of binder. Stirring uniformly, and putting into a mould for compression molding;

(3) putting the green bricks into a drying furnace for drying treatment;

(4) and sintering the dried dry green bricks, and then cooling to room temperature to obtain the red mud sintered bricks.

In the red mud sintered brick preparation process, the red mud is Bayer process red mud or sintering process red mud.

In the red mud baked brick preparation process, the granularity of the untreated red mud particles is 1-5 mm.

In the red mud sintered brick preparation process, the granularity of the pretreated red mud is 200 meshes below the sieve.

In the red mud baked brick preparation process, the molding pressure in the step (2) is preferably 10-15MPa, and the preferred binder is 10-20%.

In the red mud baked brick preparation process, the drying temperature in the step (3) is preferably 60-100 ℃ for 1-2 days.

In the red mud sintered brick preparation process, the sintering temperature in the step (4) is preferably 900-1000 ℃.

The invention utilizes the red mud and the waste glass to prepare the high-strength red mud baked brick, the baked brick has two remarkable advantages of high strength and corrosion resistance , and the red mud is used as the aggregate, so that the red mud content in the red mud type baked brick reaches more than 80 percent, the red mud waste is fully used, the comprehensive utilization rate of the red mud is improved, and the pollution to the environment is reduced.

Drawings

FIG. 1 is a scanning electron microscope image of a section of a red mud baked brick obtained in the present patent.

Detailed Description

Example 1

Step 1: carrying out high-temperature sintering pretreatment on the red mud, putting the red mud into a high-temperature furnace at 600 ℃ for heat preservation for 1h, and sieving the red mud by a 200-mesh sieve;

step 2: the ingredients are as follows by mass percent: 72wt% of red mud, 8wt% of waste glass and 20wt% of binder. Stirring uniformly, and putting into a mould for compression molding;

and step 3: putting the green brick into a drying furnace at 60 ℃, and preserving heat for 24 hours;

and 4, step 4: and (3) putting the dried dry green bricks into a high-temperature furnace, heating the dried dry green bricks to 900 ℃ from room temperature (the heating rate is 5 ℃/min), then preserving the heat for 60min, and then naturally cooling the dried dry green bricks to the room temperature.

Example 2

Step 1: carrying out high-temperature sintering pretreatment on the red mud, putting the red mud into a 650 ℃ high-temperature furnace for heat preservation for 1h, and sieving the red mud by a 200-mesh sieve;

step 2: the ingredients are as follows by mass percent: 64wt% of red mud, 16wt% of waste glass and 20wt% of binder. Stirring uniformly, and putting into a mould for compression molding;

and step 3: putting the green brick into a drying furnace at 90 ℃, and preserving heat for 24 hours;

and 4, step 4: and (3) putting the dried dry green bricks into a high-temperature furnace, heating the dried dry green bricks to 950 ℃ from room temperature (the heating rate is 5 ℃/min), then preserving the heat for 70min, and then naturally cooling the dried dry green bricks to the room temperature.

Example 3

Step 1: carrying out high-temperature sintering pretreatment on the red mud, putting the red mud into a high-temperature furnace at 700 ℃ for heat preservation for 1h, and sieving the red mud by a 200-mesh sieve;

step 2: the ingredients are as follows by mass percent: 80wt% of red mud, 10wt% of waste glass and 10wt% of binder. Stirring uniformly, and putting into a mould for compression molding;

and step 3: putting the green brick into a drying furnace at 110 ℃, and preserving heat for 24 hours;

and 4, step 4: and (3) putting the dried dry green bricks into a high-temperature furnace, heating the dried dry green bricks to 1000 ℃ from room temperature (the heating rate is 5 ℃/min), then preserving the heat for 70min, and then naturally cooling the dried dry green bricks to the room temperature.

Example 4

step 2: the ingredients are as follows by mass percent: 75wt% of red mud, 15wt% of waste glass and 10wt% of binder. Stirring uniformly, and putting into a mould for compression molding;

and 4, step 4: and (3) putting the dried dry green bricks into a high-temperature furnace, heating the dried dry green bricks to 1050 ℃ from room temperature (heating rate: 5 ℃/min), then preserving the heat for 70min, and then naturally cooling the dried dry green bricks to the room temperature.

The above embodiments are merely preferred embodiments of the present invention, and should not be construed as limiting the present invention, and the scope of the present invention should be defined by the claims.

Claims

1. The invention relates to red mud baked bricks, which are characterized in that the ingredients comprise, by mass, 50-90wt% of red mud, 6-50wt% of waste glass and 5-25wt% of a binder.

2. The red mud sintered brick as claimed in claim 1, wherein the red mud is subjected to a high temperature calcination pretreatment at 400-700 ℃ for 1-3 h.

3. The red mud sintered brick according to claim 1 to 2, wherein the red mud and the waste glass have a particle size of 200 meshes or less.

4. The red mud sintered brick as claimed in claim 1 to 3, wherein said binder is water, further steps being optimized to 10-20 wt%.

5. The red mud sintered brick as set forth in claims 1 to 4, wherein said waste glass is at least kinds of common plate glass, tempered glass, embossed glass and CRT glass.

6. The red mud sintered brick as claimed in claim 1 to 5, wherein the red mud is prepared by at least kinds selected from Bayer process, sintering process and mixed-series process.

7. The red mud baked brick as claimed in claims 1 to 6, wherein the raw materials are mixed in proportion, water is added to the mixture, the mixture is stirred uniformly, and the mixture is placed into a die for pressing, and the forming pressure is 5 to 30 MPa.

8. The red mud sintered brick as claimed in claims 1 to 7, wherein the drying treatment is carried out after press forming, the drying temperature is 60 to 100 ℃, and the drying time is 1 to 2 days.

9. The red mud sintered brick as claimed in claims 1-8, wherein the dried dry brick is sintered from room temperature to 850 ℃ and 1050 ℃, the heating rate is 5-10 ℃/min, and the sintering time is 10-70 min.

10. The red mud sintered brick according to claims 1 to 9, wherein said red mud sintered brick has the following properties: the density is 1.5-2.2g/cm³The compressive strength is 20-40MPa, the breaking strength is 7-13MPa, the material belongs to building materials, and the material can be practically applied to field bricks, road bricks and other aspects.