WO2021033193A1

WO2021033193A1 - Red brick and process for preparation thereof

Info

Publication number: WO2021033193A1
Application number: PCT/IN2019/050858
Authority: WO
Inventors: Satish Narain JAJOO; Rajesh Kumar Saini; Anil Kumar Pandey
Original assignee: Hindalco Industries Limited
Priority date: 2019-08-22
Filing date: 2019-11-20
Publication date: 2021-02-25
Also published as: EP4017838A1; EP4017838A4; AU2019462547A1; BR112022003387A2; CN114787099A

Abstract

The present disclosure relates to a red brick comprising: 20-50 wt% of red mud; 10-20 wt% of bottom ash; 10-30 wt% of natural sand; 15-30 wt% of fly ash; and 4-15 wt% of Portland cement. The present disclosure also relates to a process for preparing a red brick comprising: mixing 20-50 wt% of red mud, 10-20 wt% of bottom ash, 10-30 wt% of natural sand to form a first mixture, adding 15-30 wt% of fly ash and 4-15 wt% of Portland cement to the first mixture to form a second mixture, rolling the second mixture in a pan mixer having roller and scraper to produce a final mixture, molding the final mixture in a brick press to provide a pressed red brick, and stacking the pressed red brick in yards to form a red brick.

Description

RED BRICK AND PROCESS FOR PREPARATION THEREOF

FIELD OF THE INVENTION

The present disclosure relates to red bricks made up of waste material generated in power plant and alumina refinery.

The present disclosure also related to a process of preparation of red bricks using the waste material generated in power plant and alumina refinery.

BACKGROUND OF THE INVENTION

Bricks are the most used building materials in construction industry. It is being used to construct walls, foundations and many other parts of buildings and other masonry structures. Bricks are laid in courses and other many patterns termed as bond, it may be laid with various kinds of mortar to hold the bricks together and make a durable structure. The structures may be load bearing or just partition walls.

There are many types of bricks available based on their use, size, forming methods, quality and material used for construction. Most common are clay bricks and chemically set bricks. Generally, clay bricks are baked in kiln after moulding and drying. Chemically set bricks are mixed with chemical or cement moulded and dried in open air and curing with watering or without watering. It gains strength with chemical reaction within it and therefore, there is no need of baking in kiln.

Conventional clay bricks are made with the precious earth material which is being depleted day by day. It is also a concern from an environmental conservation point of view. It also requires huge amount of fossil fuel i.e. coal for baking it.

Red mud is an industrial waste from an alumina-producing industry. The red mud is composed mainly of iron oxide, and hence is red in colour. The quantity of red mud produced per ton of alumina produced, is generally about 1-2.5 tons. The red mud is generally disposed of, posing environmental problems. Chinese Patent Application Number CN101468905 discloses red mud unburned brick which mainly consists of 5-30 parts of red mud, 20-30 parts of fly ash, 20-50 parts of quartz sand or gravel powder, 5-15 parts of lime, 2-8 portions of gypsum and 0-3 parts of cement. Chinese Patent Application Number CN1079452 discloses a red mud composite brick comprising red mud, fly ash, lime, gypsum and sand. Another Chinese Patent Application Number CN101215142 relates to Bayer red mud composite brick, prepared by mixing raw materials of 20-35 parts of Bayer red mud, 15-34 parts of fly ash, 5-15 parts of carbide slag, 30-40 parts of slag, 5-12 parts of cement and 0-5 parts of gypsum. Chinese Patent Application Number CN 101020603 discloses light red mud brick and its making process. The red brick in this publication is composed of 15-50 parts of red mud, 35-70 parts of fly ash, 8-12 parts of lime and 4-6 parts of silica sand.

In making of bricks, carbide lime mostly used and it is by product of gas making plants and does not meet consistency in quality. Purity of such lime varies from 40 to 70%. Due to such non-consistency of lime quality, brick quality also gets affected and varies in compressive strength. Therefore, there is a need for an alternative to compositions using lime.

OBJECTIVES OF THE INVENTION

The primary object of the present disclosure is to provide a red brick comprising red mud; bottom ash; natural sand; fly ash; and Portland cement.

Another objective of the present disclosure is to provide a red brick having compressive strength of not less than 75 kg/cm².

Yet another objective of the present disclosure is to provide a process for preparing a red brick.

Further an objective of the present disclosure is to provide a red brick made up of waste material generated in power plant and alumina refinery. SUMMARY OF THE INVENTION

The present disclosure relates to a red brick comprising: 20-50 wt% of red mud; 10-20 wt% of bottom ash; 10-30 wt% of natural sand; 15-30 wt% of fly ash; and 4-15 wt% of Portland cement.

The present disclosure also relates to a process for preparing a red brick comprising: mixing 20-50 wt% of red mud, 10-20 wt% of bottom ash, 10-30 wt% of natural sand to form a first mixture; adding 15-30 wt% of fly ash and 4-15 wt% of Portland cement to the first mixture to form a second mixture; rolling the second mixture in a pan mixer having roller and scraper to produce a final mixture; moulding the final mixture in a brick press to provide a pressed red brick; and stacking the pressed red brick in yards to form a red brick.

These and other features, aspects, and advantages of the present subject matter will become better understood with reference to the following description and appended claims. This summary is provided to introduce a selection of concepts in a simplified form. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.

DETAILED DESCRIPTION OF THE INVENTION

The present disclosure provides a red brick comprising: 20-50 wt% of red mud; 10-20 wt% of bottom ash; 10-30 wt% of natural sand; 15-30 wt% of fly ash; and 4-15 wt% of Portland cement.

The red brick of the present disclosure has compressive strength of not less than 75 kg/cm². The red mud is a bi-product of Alumina refinery in aluminum manufacturing plant. It is generated in the process of extracting alumina from Bauxite ore. It is approx. 50 to 60 % of Bauxite used for alumina extraction. After drying and sieving the red mud (collected from pond), it is ready to use for red brick manufacturing.

The fly ash used in the present application has a particle size in the range of 90 Micron to 600 Micron. The fly ash is very fine material generated in thermal power plant in process of burning coal in boilers to produce thermal energy. The total ash generation is normally 40% of coal fed in boilers. The fly ash generation is approx. 80% of total ash generation. Normally it is collected through electrostatic precipitators. Fly ash has a higher reactivity, and it acts as binding materials in reaction with cement. The fly ash is directly mixed in red brick manufacturing.

The bottom ash has a particle size in the range of 0.15 mm to 4.75 mm. The bottom ash is also a bi-product of coal burning in boilers of thermal plant. It is coarser in nature. Bottom ash generation is approx. 20% of total as generation in thermal power plant. Bottom ash has a reactivity value of 5-7% which helps to increase the strength of the brick. Due to less reactivity, bottom ash also acts as filler material like natural sand. After getting desired particle size, it is ready to use in red brick manufacturing.

The natural sand has a particle size in the range of 0.3 mm to 4.75 mm. Natural sand is found in river bed. The dried sand is cleaned to remove any foreign materials and it is ready to use in red brick manufacturing. Natural sand acts as a filler material.

Bottom ash has lesser number of coarse particles in comparison to natural sand. A combination of sand and bottom ash meets the desired particle size distribution of the composition of the composition for better workability of mix during the manufacturing of red bricks.

Portland cement is a standard product available in market. It is a binding material commonly used in building construction industries. It reacts with filler materials and develops strength. It is directly added in red brick manufacturing. The Portland cement contains gypsum. Gypsum is available as a bi-product of chemical and fertilizer industries. Gypsum also influences the setting process of brick and gaining early strength.

The present disclosure also provides a process for preparing a red brick comprising: mixing 20-50 wt% of red mud, 10-20 wt% of bottom ash, 10-30 wt% of natural sand to form a first mixture, adding 15-30 wt% of fly ash and 4-15 wt% of Portland cement to the first mixture to form a second mixture, rolling the second mixture in a pan mixer having roller and scraper to produce a final mixture, moulding the final mixture in a brick press to provide a pressed red brick, and stacking the pressed red brick in yards to form a red brick. The rolling of second mixture in the pan mixer is carried out for 3 minutes, at 28-35 °C. The molding of final mixture is carried out for 30 Sec, at 28-35 °C. The stacking of pressed red brick is carried out for 3 days inside shed and 12 days in open yard, at atmospheric temperature and pressure. Further, the natural sand is dried and cleaned to remove foreign materials before mixing with red mud and bottom ash to obtain the first mixture.

The developed red bricks are made using 70% waste material generated in power plant and alumina refinery. These bricks are not required to burn in kiln and no air pollution is caused due to burning of huge coal in normal lay bricks production. The parameters such as Compressive Strength, Size, Weight, Water Absorption and Efflorescence, of the red bricks of the present application are comparative to normal clay bricks which are commercially available.

These red bricks gain required strength in 15 days in open area and ready to use. As it is machine produced so there is no any dimensional variation, it is little higher in weight but very little water absorbent.

The advantages of the present disclosure include utilization of waste generated in power plant and alumina refineries, up-cycling of waste to useful product, low costs as machine production is involved. As no precious earth/clay is being used, and no coal is burnt as it is a cold setting material, it also saves environment. There is no deformation in shape and size, and the red bricks are comparable to normal clay bricks in shape, size, appearance and strength.

EXAMPLES

The following examples are given by way of illustration of the present invention and should not be construed to limit the scope of present disclosure. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are intended to provide further explanation of the subject matter.

EXAMPLE 1: Preparation of Red Brick 13 wt% of Bottom ash in the particle size range of 0.15 mm to 4.75 mm, 20 wt% of natural sand in the particle size range of 0.3 mm to 4.75 mm and 31 wt% of red mud were mixed to form a first mixture. To this first mixture, 25 wt % of fly ash in the particle size range of 45 pm to 600 pm, and 11 wt % of Portland cement were added and mixed to form a second mixture. The second mixture thus formed was then rolled for 3 minutes in a pan mixer having roller and scraper at 30 °C to produce final mixture. This final mixture was moulded for 30 seconds in a brick press at 30 °C to provide a pressed red brick. The pressed red brick was stacked for 3 days inside shed and 12 days in open area in yards at atmospheric temperature and pressure to form a red brick.

The red brick thus formed has a composition as set out in the table below -

Table 1. Composition of the Red Brick 1

EXAMPLE 2: Preparation of Red Brick 2

13 wt% of Bottom ash in the particle size range of 0.15 mm to 4.75 mm, 20 wt% of natural sand in the particle size range of 0.3 mm to 4.75 mm and 32 wt% of red mud were mixed to form a first mixture. To this first mixture, 25 wt % of fly ash in the particle size range of 45 pm to 600 pm, and 10 wt % of Portland cement were added and mixed to form a second mixture. The second mixture thus formed was then rolled for 3 minutes in a pan mixer having roller and scraper at 28 °C to produce final mixture. This final mixture was moulded for 30 Sec in a brick press at 28 °C to provide a pressed red brick. The pressed red brick was stacked for 3 days inside shed and 12 days in open area in yards at atmospheric temperature and pressure to form a red brick.

The red brick thus formed has a composition as set out in the table below -

Table 2. Composition of the Red Brick 2

EXAMPLE 3: Preparation of Red Brick

20 wt% of Bottom ash in the particle size range of 0.15 mm to 4.75 mm, 20 wt% of natural sand in the particle size range of 0.3 mm to 4.75 mm and 40 wt% of red mud were mixed to form a first mixture. To this first mixture, 15 wt % of fly ash in the particle size range of 45 pm to 600 pm, and 5 wt % of Portland cement were added and mixed to form a second mixture. The second mixture thus formed was then rolled for 3 minutes in a pan mixer having roller and scraper at 32 °C to produce final mixture. This final mixture was moulded for 30 seconds in a brick press at 32 °C to provide a pressed red brick. The pressed red brick was stacked for 3 days inside shed and 12 days in open area in yards at atmospheric temperature and pressure to form a red brick.

The red brick thus formed has a composition as set out in the table below -

Table 3. Composition of the Red Brick 3

EXAMPLE 4: Preparation of Red Brick 15 wt% of Bottom ash in the particle size range of 0.15 mm to 4.75 mm, 25 wt% of natural sand in the particle size range of 0.3 mm to 4.75 mm and 34 wt% of red mud were mixed to form a first mixture. To this first mixture, 20 wt % of fly ash in the particle size range of 45 pm to 600 pm, and 6 wt % of Portland cement were added and mixed to form a second mixture. The second mixture thus formed was then rolled for 3 minutes in a pan mixer having roller and scraper at 34 °C to produce final mixture. This final mixture was moulded for 30 seconds in a brick press at 34 °C to provide a pressed red brick. The pressed red brick was stacked for 3 days inside shed and 12 days in open area in yards at atmospheric temperature and pressure to form a red brick.

The red brick thus formed has a composition as set out in the table below -

Table 4. Composition of the Red Brick 4

EXAMPLE 5: Preparation of Red Brick

15 wt% of Bottom ash in the particle size range of 0.15 mm to 4.75 mm, 15 wt% of natural sand in the particle size range of 0.3 mm to 4.75 mm and 45 wt% of red mud were mixed to form a first mixture. To this first mixture, 17 wt % of fly ash in the particle size range of 45 pm to 600 pm, and 8 wt % of Portland cement were added and mixed to form a second mixture. The second mixture thus formed was then rolled for 3 minutes in a pan mixer having roller and scraper at 35 °C to produce final mixture. This final mixture was moulded for 30 seconds in a brick press at 35 °C to provide a pressed red brick. The pressed red brick was stacked for 3 days inside shed and 12 days in open area in yards at atmospheric temperature and pressure to form a red brick.

The red brick thus formed has a composition as set out in the table below - Table 5. Composition of the Red Brick 5

EXAMPLE 6: Testing of compressive strength of red bricks

The red bricks of the present disclosure were tested for compressive strength in comparison with the commercially available clay bricks, such as MEERA, DLX, SAMAJ, TRISHOOL, KAMAL and JAMUNA. Comparison of the compressive strengths are shown in the table below -

Table 6. Comparison of compressive strengths

* HIL, RPD Lab= Hindalco Industries Limited (Unit Renusagar Power Division) Lab It is clear from the table above that the red bricks of the present disclosure have superior compressive strength than the commercially available clay bricks. EXAMPLE 7: Testing of various other parameters of red bricks with the commercially available clay bricks The red bricks of the present disclosure were tested for parameters like water absorption, efflorescence, etc. in comparison with the commercially available clay bricks, such as ATUL Brand.

Comparison of the parameters are shown in the table below -

Table 7. Comparison of Red Mud Bricks (RPD) & Local Bricks

COMPARATIVE EXAMPLES The red bricks of the present disclosure were compared to the red bricks with lime but without bottom ash. The table below gives the comparison of the red bricks of the present disclosure with the red bricks with lime but without bottom ash. Table 8. Comparison of red bricks of present disclosure with the red bricks with lime but without bottom ash

As can be seen above, the red bricks of the present disclosure exhibit superior compressive strength than the red bricks with lime but without bottom ash.

Although the subject matter has been described in considerable detail with reference to certain preferred embodiments thereof, other embodiments are possible. As such, the spirit and scope of the appended claims should not be limited to the description of the preferred embodiment contained therein.

Claims

WE CLAIM

1. A red brick comprising:

20-50 wt% of red mud;

10-20 wt% of bottom ash;

10-30 wt% of natural sand;

15-30 wt% of fly ash; and 4-15 wt% of Portland cement.

2. The red brick as claimed in claim 1, having compressive strength in the range of 75- 110 kg/cm².

3. The red brick as claimed in claim 1, wherein the fly ash has a particle size in the range of 45 Micron to 600 Micron.

4. The red brick as claimed in claim 1, wherein the bottom ash has a particle size in the range of 0.3mm to 4.75mm.

5. The red brick as claimed in claim 1, wherein the natural sand has a particle size in the range of 0.3mm to 4.75mm.

6. A process for preparing a red brick comprising: mixing 20-50 wt% of red mud, 10-20 wt% of bottom ash, 10-30 wt% of natural sand to form a first mixture; adding 15-30 wt% of fly ash and 4-15 wt% of Portland cement to the first mixture to form a second mixture; rolling the second mixture in a pan mixer having roller and scraper to produce a final mixture; moulding the final mixture in a brick press to provide a pressed red brick; and stacking the pressed red brick in yards to form a red brick.

7. The process as claimed in claim 6, wherein the rolling is carried out for 3 minutes, at 28-35 °C.

8. The process as claimed in claim 6, wherein the moulding is carried out for 30 sec, at 28-35 °C.

9. The process as claimed in claim 6, wherein the stacking is carried out for 3 days inside shed and 12 days in open area in yards, at atmospheric temperature and pressure.

10. The process as claimed in claim 6, wherein the natural sand is dried and cleaned to remove foreign materials before mixing with red mud and bottom ash to obtain the first mixture.