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

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

A kind of red mud sintered brick and preparation method thereof

technical field

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

Background technique

Red mud is an industrial waste produced in the process of aluminum production. At present, the total amount of red mud produced in the world every year is about 0.7-120 million tons]. As the fourth largest alumina producer in China, since the establishment of the first alumina plant in 1945, with the vigorous development of the aluminum industry, the discharge of red mud in my country has been increasing, and the amount of red mud that has been discharged so far has exceeded 50 million. At present, millions of tons of red mud are discharged every year, but the comprehensive utilization rate of red mud is only 4%. As a result, a large amount of red mud can only be disposed of by stacking in the yard and occupies a large amount of land resources. And because red mud contains a lot of alkalis, heavy metals and other potential pollutants, it will cause great harm to the land and directly or indirectly harm people's health.

Glass products have long been widely used in industrial production and daily life. The huge demand has given birth to the prosperity of the glass industry, and with it, a large amount of glass waste has been generated. my country produces about 10 million tons of waste glass every year, accounting for about 5% of the total solid waste. Due to the different models produced by manufacturers, its recycling is also a huge problem

With the rapid development of the construction industry, my country consumes about 750 billion sintered bricks (converted into standard bricks) every year. If such a large number of sintered bricks are made of clay, a large number of fertile fields will be destroyed. Therefore, the Chinese government has repeatedly proposed to prohibit the production and use of clay solid sintered bricks, and to encourage the use of various industrial waste residues to make bricks to protect the clay and the arable land on which it depends. The use of red mud to make bricks can achieve a win-win situation in environmental protection and profit, and has become a research hotspot. The purpose of this patent is to use red mud and waste glass to prepare sintered bricks. On the one hand, it can realize the utilization of waste and improve its utilization value; Utilize existing resources and protect the environment.

SUMMARY OF THE INVENTION

Aiming at the problem of low comprehensive utilization rate of red mud, the present invention provides a preparation method for preparing sintered bricks by using red mud. The method uses red mud and waste glass as main raw materials, which greatly improves the comprehensive utilization of solid waste. In addition, the sintered bricks in this patent are characterized by fewer types of raw materials, simple preparation process and low cost.

The red mud sintered brick and preparation process of the present invention include:

(1) The red mud is pretreated by high temperature sintering, put into a high temperature furnace of 400-700 ℃ for 1-3 hours, and passed through a 200-mesh sieve;

(2) The ingredients are mixed by mass percentage: red mud 50-90wt%, waste glass 6-50wt%, and binder 5-25wt%. Stir evenly, put it into the mold and press it;

(3) Put the bricks into the drying furnace for drying treatment;

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

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

In the process for preparing red mud sintered bricks, the particle size of untreated red mud particles is 1-5 mm.

In the preparation process of the red mud sintered brick, the particle size of the pretreated red mud is 200 mesh sieves.

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

In the preparation process of the red mud sintered brick, in step (3), the drying temperature is preferably 60-100° C., and the time is 1-2 d.

In the process for preparing red mud sintered bricks, the preferred sintering temperature in step (4) is 900-1000°C.

The present invention utilizes red mud and waste glass to prepare high-strength red mud sintered bricks. Such fired bricks have two significant advantages. First, it has high strength and corrosion resistance. The second is to use red mud as aggregate, so that the content of red mud in red mud type sintered bricks can reach more than 80%, make full use of red mud waste, improve the comprehensive utilization rate of red mud, and reduce its pollution to the environment.

Description of drawings

Fig. 1 is the sectional scanning electron microscope picture of the red mud sintered brick obtained by this patent.

Detailed ways

Example 1

Step 1: The red mud is subjected to high temperature sintering pretreatment, placed in a 600°C high temperature furnace for 1 hour, and passed through a 200-mesh sieve;

Step 2: The ingredients are mixed by mass percentage: 72 wt % of red mud, 8 wt % of waste glass, and 20 wt % of binder. Stir evenly, put it into the mold and press it;

Step 3: Put the brick into a drying furnace at 60°C and keep it warm for 24h;

Step 4: Put the dried bricks into a high-temperature furnace, heat up from room temperature to 900°C (heating rate: 5°C/min), keep the temperature for 60 minutes, and then naturally cool to room temperature.

Example 2

Step 1: The red mud is subjected to high temperature sintering pretreatment, placed in a 650°C high temperature furnace for 1 hour, and passed through a 200-mesh sieve;

Step 2: The ingredients are mixed by mass percentage: 64wt% red mud, 16wt% waste glass, and 20wt% binder. Stir evenly, put it into the mold and press it;

Step 3: Put the brick into a drying furnace at 90°C and keep it warm for 24h;

Step 4: Put the dried bricks into a high-temperature furnace, heat up from room temperature to 950°C (heating rate: 5°C/min), keep the temperature for 70 minutes, and then naturally cool to room temperature.

Example 3

Step 1: The red mud is subjected to high temperature sintering pretreatment, placed in a high temperature furnace of 700°C for 1 hour, and passed through a 200-mesh sieve;

Step 2: The ingredients are mixed by mass percentage: red mud 80wt%, waste glass 10wt%, and binder 10wt%. Stir evenly, put it into the mold and press it;

Step 3: Put the brick into a drying furnace at 110°C and keep it warm for 24h;

Step 4: Put the dried bricks into a high-temperature furnace, heat up from room temperature to 1000°C (heating rate: 5°C/min), keep the temperature for 70 minutes, and then naturally cool to room temperature.

Example 4

Step 1: The red mud is subjected to high temperature sintering pretreatment, placed in a 600°C high temperature furnace for 1 hour, and passed through a 200-mesh sieve;

Step 2: The ingredients are mixed by mass percentage: red mud 75wt%, waste glass 15wt%, and binder 10wt%. Stir evenly, put it into the mold and press it;

Step 3: Put the brick into a drying furnace at 60°C and keep it warm for 24h;

Step 4: Put the dried bricks into a high-temperature furnace, heat up from room temperature to 1050°C (heating rate: 5°C/min), keep the temperature for 70 minutes, and then naturally cool to room temperature.

The above-mentioned embodiments are only relatively excellent technical solutions in the process of the present invention, and should not be regarded as a limitation of the present invention, and the protection scope of the present invention should be based on the technical solutions recorded in the claims.

Claims (10)

1. A red mud sintered brick according to the present invention is characterized in that the mass percentages of ingredients are: red mud 50-90wt%, waste glass 6-50wt%, and binder 5-25wt%. 2 . The red mud sintered brick according to claim 1 , wherein the red mud is subjected to high temperature calcination pretreatment, the calcination temperature is 400-700° C., and the calcination time is 1-3 h. 3 . 3. The red mud sintered brick according to claim 1-2, characterized in that, the granularity of the red mud and waste glass is under 200 meshes. 4. The red mud sintered brick according to claim 1-3, wherein the binder is water, which is further optimized to be 10-20wt%. 5 . The red mud sintered brick according to claim 1 , wherein the waste glass is at least one of ordinary flat glass, tempered glass, patterned glass and CRT glass. 6 . 6 . The red mud sintered brick according to claim 1 , wherein the preparation method of the red mud is at least one of Bayer method, sintering method and hybrid method. 7 . 7. The red mud sintered brick according to claim 1-6, characterized in that, the raw materials are mixed in proportion, water is added to the mixture, stirred evenly, put into a mold and pressed, and the molding pressure is 5-30MPa. 8. The red mud sintered brick according to claim 1-7, characterized in that, after pressing and forming, drying treatment is carried out, the drying temperature is 60-100 DEG C, and the drying time is 1-2d. 9. The red mud sintered brick as claimed in claim 1-8, characterized in that, the dried brick blanks after drying are sintered, rising from room temperature to 850-1050 ℃, and the heating rate is 5-10 ℃/min , the firing time is 10-70min. 10. The red mud sintered brick according to claim 1-9, characterized in that, the properties of the red mud sintered brick: density 1.5-2.2g/cm compressive strength ^20-40MPa , flexural strength: 7-13MPa, which belongs to building materials, can be practically used in square bricks, road bricks, etc.

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