Claims:CLAIMS
I/We Claim:
1. A coal ash brick (102) comprising:
a pond ash (104), in a range of 20% to 26% by weight having a particle size in a range of 10 micrometers (µm) to 50 µm;
a fly ash (106) of 35% by weight, having a Calcium Oxide (CaO) content less than 5% by weight, wherein a particle size of the fly ash (106) is in a range of 10 micrometers (µm) to 50 µm;
a gypsum (108) of 5% by weight;
a sand (110) of 20% by weight; and
a lime (112) having the Calcium Oxide (CaO) content greater than or equal to 20% by weight.
2. The brick as claimed in claim 1, wherein a specific gravity of the pond ash (104) is 2.25.
3. The brick as claimed in claim 1, wherein a specific gravity of the fly ash (106) is 2.31.
4. The brick as claimed in claim 1, wherein a specific gravity of the sand (110) is 2.66.
5. The brick as claimed in claim 1, wherein the lime (112) is added to accelerate a hardening process of the coal ash brick (102) to obtain an early strength.
6. A method for manufacturing a coal ash brick (102), wherein the method comprising steps of:
mixing a pond ash (104) in a range of 20% to 26% by weight, a fly ash (106) having a Calcium Oxide (CaO) content less than 5% by weight, a gypsum (108) of 5% by weight; a sand (110) of 20% by weight; and a lime (112) having the Calcium Oxide (CaO) content greater than or equal to 20% by weight in a mixer (114) to create a mixture (100);
conveying the mixture (100) into a brick mold through a conveyor;
casting the coal ash brick (102) using the brick mold, wherein a size of the casted coal ash brick (102) is 230 millimeters (mm) x 110 mm x 75 mm; and
curing the casted coal ash brick (102) using a normal water curing.
7. The method as claimed in claim 6, wherein a specific gravity of the pond ash (104) is 2.25 and a particle size of the pond ash (104) in a range of 10 micrometers (µm) to 50 µm.
8. The method as claimed in claim 6, wherein a specific gravity of the fly ash (106) is 2.31 and a particle size of the fly ash (106) is in a range of 10 micrometers (µm) to 50 µm.
9. The method as claimed in claim 6, wherein a specific gravity of the sand (110) is 2.66.
10. The method as claimed in claim 6, wherein a compressive strength of the coal ash brick (102) is in a range of 9.2 Newton per millimeter2 (N/mm²) to 7.6 N/mm².
Date: 23 July 2020
Place: Noida

Dr. Keerti Gupta
Agent for the Applicant
(IN/PA-1529)

, Description:FORM 2

THE PATENT ACT 1970
(39 of 1970)
&

THE PATENTS RULES, 2003

COMPLETE SPECIFICATION
(See Section 10, and rule 13)

TITLE OF THE INVENTION
METHOD FOR MANUFACTURING COAL ASH BRICK
APPLICANT(S)
NAME: Dr. R Gobinath
NATIONALITY: INDIAN
ADDRESS: S R Engineering College, Ananthasagar (V), Hasanparthy (M), Warangal, Telangana, 560 371

The following specification particularly describes the invention and the manner in which it is to be performed
BACKGROUND
Field of Invention
[001] Embodiments of the present invention generally relate to a method for utilizing a waste product, and more particularly to a method for manufacturing bricks from a waste generated from power plants.
Description of Related Art
[002] Fossil fuel power stations are amongst the most reliable and most dependable power generating sources that are used to generate electricity from burning of fossil fuels. A coal power plant is one of the fossil fuel power stations, which burns tons of coal to generate the electricity. However, the coal power plants generate a lot of waste residue that is very harmful for the environment. The burning of coal produces byproducts such as fly ash, and bottom ash. The byproducts are dumped into an ash pond, or a coal ash basin for preventing a release of ash into the environment. Moreover, the ash pond is used in combination with air pollution control methods such as, wet scrubbers to decreases a number of airborne pollutants. However, the ash pond can pose serious health risks for the surrounding environment.
[003] Many researches have been carried out on effective utilization of the fly ash and the pond ash in construction industry as the fly ash and the pond ash possess suitable pozzolanic properties that can be utilized in making different construction materials.
[004] There is thus a need for method for managing byproducts of coal power plants in a more efficient manner.
SUMMARY
[005] Embodiments in accordance with the present invention provide a coal ash brick. The coal ash brick comprising a pond ash, in a range of 20% to 26% by weight, having a particle size in a range of 10 micrometers (µm) to 50 µm. Further, the coal ash brick comprises a fly ash (106) of 35% by weight, having a Calcium Oxide (CaO) content less than 5% by weight, wherein a particle size of the fly ash (106) is in a range of 10 micrometers (µm) to 50 µm. Further, the coal ash brick comprises a gypsum (108) of 5% by weight. Further, the coal ash brick comprises a sand (110) of 20% by weight. Further, the coal ash brick comprises the lime having a Calcium Oxide (CaO) content greater than or equal to 20% by weight.
[006] Embodiments in accordance with the present invention further provide a method for manufacturing a coal ash brick. The method comprising steps of: mixing a pond ash in a range of 20% to 26% by weight, a fly ash having a Calcium Oxide (CaO) content less than 5% by weight, a gypsum of 5% by weight; a sand of 20% by weight; and a lime having the Calcium Oxide (CaO) content greater than or equal to 20% by weight in a mixer to create a mixture. Further conveying the mixture into a brick mold through a conveyor; casting the coal ash brick using the brick mold, wherein a size of the casted coal ash brick is 230 millimeters (mm) x 110 mm x 75 mm. Further curing the casted coal ash brick using a normal water curing.
[007] Embodiments of the present invention may provide a number of advantages depending on its particular configuration. First, embodiments of the present application provide a method for manufacturing a brick using a pond ash and a fly ash. Next, embodiments of the present application provide a method for manufacturing a high strength brick.
[008] These and other advantages will be apparent from the present application of the embodiments described herein.
[009] The preceding is a simplified summary to provide an understanding of some embodiments of the present invention. This summary is neither an extensive nor exhaustive overview of the present invention and its various embodiments. The summary presents selected concepts of the embodiments of the present invention in a simplified form as an introduction to the more detailed description presented below. As will be appreciated, other embodiments of the present invention are possible utilizing, alone or in combination, one or more of the features set forth above or described in detail below.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The above and still further features and advantages of embodiments of the present invention will become apparent upon consideration of the following detailed description of embodiments thereof, especially when taken in conjunction with the accompanying drawings, and wherein:
[0011] FIG. 1 illustrates a mixture for manufacturing a coal ash brick, according to an embodiment of the present invention disclosed herein; and
[0012] FIG. 2 depicts a flowchart of a method for manufacturing the coal ash brick, according to an embodiment of the present invention disclosed herein.
[0013] The headings used herein are for organizational purposes only and are not meant to be used to limit the scope of the description or the claims. As used throughout this application, the word "may" is used in a permissive sense (i.e., meaning having the potential to), rather than the mandatory sense (i.e., meaning must). Similarly, the words “include”, “including”, and “includes” mean including but not limited to. To facilitate understanding, like reference numerals have been used, where possible, to designate like elements common to the figures. Optional portions of the figures may be illustrated using dashed or dotted lines, unless the context of usage indicates otherwise.
DETAILED DESCRIPTION
[0014] The following description includes the preferred best mode of one embodiment of the present invention. It will be clear from this description of the invention that the invention is not limited to these illustrated embodiments but that the invention also includes a variety of modifications and embodiments thereto. Therefore, the present description should be seen as illustrative and not limiting. While the invention is susceptible to various modifications and alternative constructions, it should be understood, that there is no intention to limit the invention to the specific form disclosed, but, on the contrary, the invention is to cover all modifications, alternative constructions, and equivalents falling within the spirit and scope of the invention as defined in the claims.
[0015] In any embodiment described herein, the open-ended terms "comprising," "comprises,” and the like (which are synonymous with "including," "having” and "characterized by") may be replaced by the respective partially closed phrases "consisting essentially of," consists essentially of," and the like or the respective closed phrases "consisting of," "consists of, the like.
[0016] As used herein, the singular forms “a”, “an”, and “the” designate both the singular and the plural, unless expressly stated to designate the singular only.
[0017] FIG. 1 illustrates a mixture 100 for manufacturing a coal ash brick 102, according to an embodiment of the present invention. The mixture 100 may comprise a pond ash 104, a fly ash 106, a gypsum 108, a sand 110, and a lime 112. Further, the pond ash 104, the fly ash 106, the gypsum 108, the sand 110 and the lime 112 may be mixed in a mixer 114, in an embodiment of the present invention.
[0018] The pond ash 104 used in the manufacturing of the coal ash brick 102 may be a waste product from a boiler of a coal power plant mainly obtained from a wet disposal of a fly ash that may be further mixed with bottom ash and disposed of in large ash ponds or dykes as slurry. According to embodiments of the present invention, a proportion of the pond ash 104 used in the manufacturing of the coal ash brick 102 may be in a range of 20% to 26% by weight. In an exemplary scenario, if the proportion of the pond ash 104 is 20%, then that signifies that there is 20 grams (gm) of the pond ash 104 in 100 gm of the mixture 100. Further, a particle size of the each of the pond ash 104 may have in a range of 10 Micrometers (µm) to 50 µm, according to embodiments of the present invention. Embodiments of the present invention are intended to include or otherwise cover any of the particle size of the pond ash 104. Furthermore, a specific gravity of the pond ash 104 that may be defined as a ratio between a weight of a given volume of the pond ash 104 and a weight of an equal volume of water may be 2.25.
[0019] The fly ash 106 may be a fine powder that may be a byproduct of a coal burnt in the coal power plant. Further, the fly ash 106 may be a pozzolan that may contain an aluminous and a siliceous material capable of forming cement in a presence of water. According to an embodiment of the present invention, the fly ash 106 may be a Class F fly ash that may comprise a Calcium Oxide (CaO) content of less than 5% by weight. The CaO content may be capable of activating the pond ash 104 and the fly ash 106 in the mixture 100. Further, a particle size of the fly ash 106 may be in a range of 10 µm to 50 µm. Embodiments of the present invention are intended to include or otherwise cover any particle size of the fly ash 106, including known, related art, and/or later developed technologies. Furthermore, a specific gravity of the fly ash 106 may be defined as a ratio between a weight of a given volume of the fly ash 106 and, a weight of an equal volume of water, which may be 2.31.
[0020] According to embodiments of the present invention, the gypsum 108 may be a soft sulfate mineral composed of Calcium Sulfate Dihydrate having a chemical formula CaSO4•2H2O that may be used as a main ingredient in manufacturing of a plaster, a blackboard, a sidewalk chalk, a drywall, and so forth. According to embodiments of the present invention, the sand 110 may be a locally available sand. In an embodiment of the present invention, the sand 110 may be a Zone II type sand as per Indian Standard (IS) 353:1970. Embodiments of the present invention are intended to include or otherwise cover any type of the sand 110, including known, related art, and/or later developed technologies. Furthermore, a specific gravity of the sand 110 that may be defined as a ratio between a weight of a given volume of the sand 110 and a weight of an equal volume of water, which may be 2.66.
[0021] According to embodiments of the present invention, the lime 112 may be an IS 6932-1973 lime considered suitable as a building material. Further, the lime 112 may have a CaO content greater than or equal to 20% by weight. The lime 112 may be added to the mixture 100 to accelerate a hardening process of the coal ash brick 102.
[0022] According to embodiments of the present invention, the mixer 114 may be a type of a concrete mixer that may be designed to mix different materials to form a homogeneous concrete mixture. The mixer 114 may be, but not limited to, a Batch Mixer, a Tilting Drum Mixer, a Non-Tilting Drum Mixer, a Reversing drum mixer, a continuous concrete mixer, and so forth. In a preferred embodiment of the present invention, the mixer 114 may be a pan mixer that may be designed to create the homogeneous concrete mixture quickly by mixing the different materials while the pan mixer is rotated in a clockwise direction, and discharging the homogeneous concrete mixture while the pan mixture is rotated in an anti-clockwise direction. Embodiments of the present invention are intended to include or otherwise cover any type of the mixer 114, including known, related art, and/or later developed technologies.
Table 1: Details of mix proportions
Mixes/Materials I II III IV
Pond ash 20 22 24 26
Fly ash 35 35 35 35
Gypsum 5 5 5 5
Sand 20 20 20 20

[0023] Table 1 depicts various mix proportions of the materials that may be used to make the coal ash brick 102, according to embodiment of the present invention. According to an embodiment of the present invention, a mix I may comprise a 20% by weight of the pond ash 104, a 35% by weight of the fly ash 106, a 5% by weight of the gypsum 108, and a 20% by weight of the sand 110 added to the mixer 114 by a user for creating the mixture 100. Further, the mixture 100 may be uniformly mixed in the mixer 114 for a predefined time period. The predefined time period may be in a range of 2 minutes to 10 minutes. Embodiments of the present invention are intended to include or otherwise cover any of the predefined time periods. Further, the mixture 100 may be conveyed to a brick mold (not shown) through a conveyor (not shown). According to an embodiment of the present invention, the brick mold may be designed to cast a brick sample of size equal to 230 millimeters (mm) x 110 mm x 75 mm as per IS 12894-2002.
[0024] According to another embodiment of the present invention, a mix II may comprises a 22% by weight of the pond ash 104, a 35% by weight of the fly ash 106, a 5% by weight of the gypsum 108, and a 20% by weight of the sand 110 added to the mixer 114 by the user for creating the mixture 100. The mixture 100 may be uniformly mixed in the mixer 114 for a predefined time period. The predefined time period may be in a range of 2 minutes to 10 minutes. Embodiments of the present invention are intended to include or otherwise cover any of the predefined time periods. Further, the mixture 100 may be conveyed to a brick mold (not shown) through a conveyor (not shown). According to an embodiment of the present invention, the brick mold may be designed to cast a brick sample of size equal to 230 millimeters (mm) x 110 mm x 75 mm as per IS 12894-2002.
[0025] According to yet another embodiment of the present invention, a mix III may comprise a 24% by weight of the pond ash 104, a 35% by weight of the fly ash 106, a 5% by weight of the gypsum 108, and a 20% by weight of the sand 110 added to the mixer 114 by the user for creating the mixture 100. The mixture 100 may be uniformly mixed in the mixer 114 for a predefined time period. The predefined time period may be in a range of 2 minutes to 10 minutes. Embodiments of the present invention are intended to include or otherwise cover any of the predefined time periods. Further, the mixture 100 may be conveyed to a brick mold (not shown) through a conveyor (not shown). According to an embodiment of the present invention, the brick mold may be designed to cast a brick sample of size equal to 230 millimeters (mm) x 110 mm x 75 mm as per IS 12894-2002.
[0026] According to yet another embodiment of the present invention, a mix IV may comprise a 26% by weight of the pond ash 104, a 35% by weight of the fly ash 106, a 5% by weight of the gypsum 108, and a 20% by weight of the sand 110 added to the mixer 114 by the user for creating the mixture 100. The mixture 100 may be uniformly mixed in the mixer 114 for a predefined time period. The predefined time period may be in a range of 2 minutes to 10 minutes. Embodiments of the present invention are intended to include or otherwise cover any of the predefined time periods. Further, the mixture 100 may be conveyed to a brick mold (not shown) through a conveyor (not shown). According to an embodiment of the present invention, the brick mold may be designed to cast a brick sample of size equal to 230 millimeters (mm) x 110 mm x 75 mm as per IS 12894-2002.
[0027] According to embodiments of the present invention, the mix I to the mix IV may be proportioned to satisfy a class designation 7.5 of bricks. Further, the user may transfer the brick mold for a curing process to increase a strength and decrease a permeability of the hardened coal ash brick 102 using a pallet truck (not shown), in an embodiment of the present invention. According to embodiments of the present invention, the curing process may be, but not limited to, a sprinkling of water, a ponding method, a membrane curing, a steam curing, and so forth. In a preferred embodiment of the present invention, the curing process may be a normal water curing. Embodiments of the present invention are intended to include or otherwise cover any type of the curing process, including known, related art, and/or later developed technologies.
[0028] According to another embodiment of the present invention, an X-Ray diffraction analysis may be performed by the user on the different materials used for casting coal ash brink 102 to obtain chemical compositions of different compounds present in the pond ash 104, the fly ash 106, the gypsum 108, and the lime 112. The X-ray diffraction analysis may be performed using an Scanning Electron Microscope (SEM) 6360 (LA) that may be configured to produce images of the coal ash brick 102 by scanning the coal ash brick 102 with a focused beam of electrons, in an embodiment of the preset invention. The X-ray diffraction analysis of the pond ash 104, the fly ash 106, the gypsum 108, and the lime 112 may be carried out by adjusting parameters of the SEM 6360 (LA) such that an ACC Voltage may be 25.0 kilovolt (kV), a probe current may be 1.00000 nanoampere (nA), a Pulse Height Analysis (PHA) mode of the SEM 6360 (LA) may be T4, a real time may be 33.26 seconds, a live time may be 26.53 seconds, a dead time may be 20%, a counting rate may be 1946 Counts Per Second (cps), and an energy range may be in a range of 0 kiloelectron Volt (keV) to 26 keV.
Table 2: Test Result of X – Ray Diffraction Analysis
Compounds Pond ash 104 Fly ash 106 Gypsum 108 Lime 110
O 50.69 51.09 50.03 34.82
Al 18.17 18.57 - 4.69
Si 30.05 30.84 2.61 7.21
Fe 1.11 - - -
Mg - - - 4.51
Ca - - 21.41 48.77
P - - 1.61 -
S - - 24.34 -
Total

[0029] Table 2 depicts the chemical compositions of the pond ash 104, the fly ash 106, the gypsum 108, and the lime 112 obtained by the X–Ray diffraction analysis. According to embodiments of the present invention, based on the X–Ray diffraction analysis, an Oxygen (O) content in the pond ash 104 may be 50.69 %, an Aluminum (Al) content in the pond ash 104 may be 18.15 %, a Silicon (Si) content in the pond ash 104 may be 30.05 %, and an Iron (Fe) content in the pond ash 104 may be 1.11 %. Further, an Oxygen (O) content in the fly ash 106 may be 51.09 %, an Aluminum (Al) content in the fly ash 106 may be 18.57 %, and a Silicon (Si) content in the fly ash 106 may be 30.84%. Further, an Oxygen (O) content in the gypsum 108 may be 50.03 %, a Silicon (Si) content in the gypsum 108 may be 2.61 %, a Calcium (Ca) content in the gypsum 108 may be 21.41 %, a Phosphorous (P) content in the gypsum 108 may be 1.61 %, and a Sulphur (S) content in the gypsum 108 may be 24.34 %. Further, an Oxygen (O) content in the lime 112 may be 34.82 %, an Aluminum (Al) content in the lime 112 may be 4.69 %, a Silicon (Si) content in the lime 112 may be 7.21 %, a Magnesium (Mg) content in the lime 112 may be 4.51 %, and a Calcium (Ca) content in the lime 112 may be 48.77 %.
[0030] According to embodiments of the present invention, the user may further test the casted coal ash brick 102 for determining properties of the coal ash brick 102 such as, but not limited to, a compressive strength, a water absorption, a weight density, an efflorescence, and so forth. Embodiments of the present invention are intended to include or otherwise cover any of the properties of the coal ash brick 102, including known, related art, and/or later developed technologies. The compressive strength of the coal ash brick 102 may be defined as a ratio between a failure load to a cross sectional area of the coal ash brick 102. According to an embodiment of the present invention, the load may be applied axially at a uniform rate of 14 Newton Per Square Millimeter (N/mm²) per minute to determine the compressive strength of the coal ash brick 102. According to embodiments of the present invention, an average compressive strength of the coal ash brick 102 at 7th day, 14th day, and 28th day may be calculated. The compressive strength value of the coal ash brick 102 may be in a range of 9.2 N/mm² to 7.6 N/mm² from the mix I to the mix IV. According to an embodiment of the present invention, the compression strength of the coal ash brick 102 made from the mix I may be 18% higher than the class designation 7.5 of the bricks.
[0031] Further, the weight density of the coal ash brick 102 may be defined as a ratio of a weight of the coal ash brick 102 to a total volume of the coal ash brick 102. According to embodiments of the present invention, the weight density of the coal ash brick 102 made from the mix I to the mix IV may be in a range of 14.53 Kilonewton Per Meter Cube (kN/m³) to 15.73 kN/m³. According to an embodiment of the present invention, the mix IV may have a lower weight density value compared to other the mix I, the mix II, and the mix III. Further, the weight density of the coal ash brick 102 may be reduced by increasing a content of the pond ash 104 in the coal ash brick 102, in an embodiment of the present invention.
[0032] Further, the water absorption test may be carried out by immersing the coal ash brick 102 for about 24 hours in portable water. Further, the coal ash brick 102 may be wiped off with a clean cloth for avoiding dripping water. The coal ash brick 102 may be weighed to determine a change in a dry weight of the coal ash brick 102. The average water absorption of the coal ash brick 102 may be less than 10%, according to an embodiment of the present invention. According to a preferred embodiment of the present invention, the water absorption of the coal ash brick 102 made up of the mix IV may be 10% lower than the water absorption of the coal ash brick 102 made from the mix I. Further, the water absorption of the coal ash brick 102 may be decreased with an increase in the content of the pond ash 104 in the coal ash brick 102.
[0033] According to an embodiment so of the present invention, soluble salts present in the coal ash brick 102 may cause efflorescence on a surface of the coal ash brick 102. The presence of soluble salts in the coal ash brick 102 may be tested by through an efflorescence test by immersing the coal ash brick 102 in water for up to 16 hours. Further, the coal ash brick 102 may be taken out and dried in a shade. Furthermore, the coal ash brick 102 may be observed and the absence of grey or white deposits on the surface of the coal ash brick 102 may indicate the absence of soluble salts.
Table 3: Test Result for properties of various coal ash brick 102 using different mix proportions
Mixes/Properties I II III IV
Compressive Strength (N/mm2) 9.2 8.7 7.9 7.6
Weight Density (kN/m3) 15.72 15.52 15.14 14.53
Water Absorption (%) 9.16 8.85 8.56 8.34

[0034] Table 3 depicts the test results for the properties of the mix I, the mix II, the mix III, and the mix IV. According embodiments of the present invention, the compressive strength of the mix I may be 9.2 N/mm2, the compressive strength of the mix II may be 8.7 N/mm2, the compressive strength of mix III may be 7.9 N/mm2, and the compressive strength of the mix IV may be 7.6 N/mm2. Further, the weight density of the mix I may be 15.72 kN/m3, the weight density of the mix II may be 15.52 kN/m3, the weight density of the mix III may be 15.14 kN/m3 and the weight density of the mix IV may be 14.53 kN/m3. Furthermore, the water absorption of the mix I may be 9.16 %, the water absorption of the mix II is 8.85 %, the water absorption of the mix III may be 8.56 % and the water absorption of the mix IV may be 8.34 %.
[0035] FIG. 2 depicts a flowchart of a method 200 for manufacturing the coal ash brick 102, according to an embodiment of the present invention.
[0036] At step 202, the user may mix, the pond ash 104, the fly ash 106 having a Calcium Oxide (CaO) content less than 5% by weight, the gypsum 108, the sand 110, and the lime 112 in the mixer 114 to create the mixture 100.
[0037] At step 204, the user may convey the mixture 100 into the brick mold (not shown) through the conveyor (not shown).
[0038] At step 206, the user may cast the coal ash brick 102 using the brick mold.
[0039] At step 208, the user may cure the casted coal ash brick 102 using a curing process. According to embodiments of the present invention, the curing process may be, but not limited to, a sprinkling of water, a ponding method, a membrane curing, a steam curing, and so forth. In a preferred embodiment of the present invention, the curing process may be a normal water curing.
[0040] At step 210, the user may test the coal ash brick 102 for properties of the coal ash brick 102 such as, but not limited to, the compressive strength, the water absorption, the weight density, the efflorescence, and so forth, as discussed above.
[0041] Embodiments of the invention are described above with reference to block diagrams and schematic illustrations of methods and systems according to embodiments of the invention. While the invention has been described in connection with what is presently considered to be the most practical and various embodiments, it is to be understood that the invention is not to be limited to the disclosed embodiments, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.
[0042] This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope the invention is defined in the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements within substantial differences from the literal languages of the claims.