Treated SLAG particles and a process for the preparation thereof

Abstract

The present disclosure relates to treated slag particles and a process for preparation of the treated slag particles. The treated particles exhibit uniform particle size, enhanced specific surface area, thereby improving the mechanical compatibility. Further, the process of the present disclosure is simple, environmentally sustainable and provides the treated slag particles with improved compressive strength.

Description

[0001] TREATED SLAG PARTICLES AND A PROCESS FOR THE PREPARATION THEREOF

[0002] FIELD

[0003] The present disclosure relates to a construction material. Particularly, the present disclosure relates to treated slag particles and a process for the preparation thereof.

[0004] DEFINITIONS

[0005] As used in the present disclosure, the following terms are generally intended to have the meaning as set forth below, except to the extent that the context in which they are used indicates otherwise.

[0006] Slump Retention: The term “slump retention” refers to the ability of freshly mixed concrete to maintain its initial slump (workability) over a period of time. It indicates how long the concrete remains workable before it starts to set or stiffen. For example, a concrete mix with a slump retention of 90 minutes can maintain its original slump for 90 minutes after mixing.

[0007] Fly ash: The term “fly ash” refers to a fine particulate residue resulting from the combustion of pulverized coal in electric power plants.

[0008] Ground granulated blast furnace slag: The term “ground granulated blast furnace slag (GGBS)” refers to a by-product formed during the production of iron in a blast furnace, wherein molten slag is rapidly quenched to form granules and subsequently ground into a fine powder.

[0009] Bottom ash: The term “bottom ash” refers to the coarse, granular material collected at the bottom of furnaces in coal-fired power plants. It is heavier than fly ash.

[0010] Mine ash: The term “mine ash” refers to the residual material left after burning coal, mainly in power plants and not directly from coal mining.

[0011] Pozzolanic properties: The term “Pozzolanic properties” refer to the ability of certain materials to react with calcium hydroxide (lime) in the presence of water to form cementitious compounds such as calcium silicate hydrate (C-S-H), which contribute to the strength and durability of concrete. BACKGROUND

[0012] The background information herein below relates to the present disclosure but is not necessarily prior art.

[0013] Slags such as fly ash, ground granulated blast furnace slag (GGBS), pond ash, bottom ash and the like, are industrial by-products generated from coal combustion and steel manufacturing processes. These materials have found significant utility in various sectors due to their pozzolanic properties. However, the effectiveness of raw slag materials is limited by factors such as irregular particle size, low surface reactivity, low specific surface area, high angular friction, and the presence of unburnt residues. The particle size of some of the slag particles go beyond 100 microns.

[0014] Traditionally, the disposal of such slags has posed environmental challenges due to land usage, leaching risks, and carbon footprints. Further, the irregular structure with non-uniform size makes slag particles of minimal to no use. The effectiveness of slags can be significantly improved through advanced processing techniques to make it a useful product, mitigating the need for the disposal of slag, which needs to be managed carefully due to environmental and regulatory challenges.

[0015] Therefore, there is a need for treated slag particles and a process for treating slag particles that mitigates the aforementioned drawbacks or at least provides an alternative solution.

[0016] OBJECTS

[0017] Some of the objects of the present disclosure, which at least one embodiment herein satisfies, are as follows:

[0018] It is an object of the present disclosure to ameliorate one or more problems of the background or to at least provide a useful alternative.

[0019] An object of the present disclosure is to provide treated slag particles with a uniform particle shape and size distribution.

[0020] Another object of the present disclosure is to provide treated slag particles having a specific shape and optimised size for better performance in various industrial applications. Still another object of the present disclosure is to provide treated slag particles with improved mechanical and pozzolanic properties.

[0021] Yet another object of the present disclosure is to provide a process for treating slag particles that facilitates temperature-controlled grinding.

[0022] Still another object of the present disclosure is to provide a process that is simple and easy to perform.

[0023] Other objects and advantages of the present disclosure will be more apparent from the following description, which is not intended to limit the scope of the present disclosure.

[0024] SUMMARY

[0025] The present disclosure relates to treated slag particles and a process for the preparation thereof.

[0026] In an aspect of the present disclosure, the treated slag particles comprise additive coated slag particles, wherein the treated slag particles are characterized by having a particle size in the range of 1 micron to 5 microns and a specific surface area in the range of 40000 m / kg to 95000 m2 / kg.

[0027] In accordance with the present disclosure, the additive is at least one selected from the group consisting of calcium, magnesium, silica, alumina, basalt, quartz, china clay, gypsum, kaolin, and calcite. The additive has a particle size in the range of 1 micron to 4 microns.

[0028] In accordance with the present disclosure, the slag particles are selected from the group consisting of fly ash, ground granulated blast furnace slag (GGBS), pond ash, mine ash and bottom ash.

[0029] In accordance with the present disclosure, a predetermined mass ratio of the additive to the slag particles is in the range of 1:9 to 1:99.

[0030] In accordance with the present disclosure, the treated slag particles are in a spherical form.

[0031] In another aspect of the present disclosure, there is provided a process for preparing treated slag particles, the process comprising the following steps: a. obtaining slag particles having predetermined characteristics; b. grinding the slag particles at a predetermined speed for a first predetermined time period to maintain a predetermined temperature during grinding to obtain ground slag particles; c. incorporating an additive to the ground slag particles in a predetermined mass ratio at the predetermined temperature for a second predetermined time period to obtain coated slag particles; and d. cooling the coated slag particles to obtain the treated slag particles.

[0032] In accordance with the present disclosure, the additive is at least one selected from the group consisting of calcium, magnesium, silica, alumina, basalt, quartz, china clay, gypsum, kaolin, and calcite.

[0033] In accordance with the present disclosure, the predetermined characteristics of the slag particles are:

[0034] • a particle size is in the range of 10 microns to 100 microns;

[0035] • at least one shape selected from the group consisting of spherical, conical, parabolic, rhomboidal, polyhedral, polygonal and cylindrical; and

[0036] • a specific gravity in the range of 2.3 to 3.7.

[0037] In accordance with the present disclosure, the predetermined speed is in the range of 15 rpm to 40 rpm.

[0038] In accordance with the present disclosure, the first predetermined time period is in the range of 30 minutes to 45 minutes.

[0039] In accordance with the present disclosure, the second predetermined time period is in the range of 10 minutes to 30 minutes.

[0040] In accordance with the present disclosure, the predetermined temperature is in the range of 55 °C to 70 °C.

[0041] In accordance with the present disclosure, a predetermined mass ratio of the additive to the slag particles is in the range of 1:9 to 1:99.

[0042] DETAILED DESCRIPTION The present disclosure relates to construction material. Particularly, the present disclosure relates to the treated slag particles and a process for the preparation thereof.

[0043] Embodiments of the present disclosure will now be described.

[0044] Embodiments are provided so as to thoroughly and fully convey the scope of the present disclosure to the person skilled in the art. Numerous details are set forth, relating to specific components and methods, to provide a complete understanding of embodiments of the present disclosure. It will be apparent to the person skilled in the art that the details provided in the embodiments should not be construed to limit the scope of the present disclosure. In some embodiments, well-known processes, well-known apparatus structures, and well-known techniques are not described in detail.

[0045] The terminology used in the present disclosure is only for the purpose of explaining a particular embodiment, and such terminology shall not be considered to limit the scope of the present disclosure. As used in the present disclosure, the forms "a,” "an," and "the" may be intended to include the plural forms as well, unless the context clearly suggests otherwise. The terms "comprises," "comprising," “including,” and “having,” are open-ended transitional phrases and therefore specify the presence of stated features, integers, steps, operations, elements, modules, units, and / or components, but do not forbid the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. The particular order of steps disclosed in the method and process of the present disclosure is not to be construed as necessarily requiring their performance as described or illustrated. It is also to be understood that additional or alternative steps may be employed.

[0046] As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed elements.

[0047] The terms first, second, third, etc., should not be construed to limit the scope of the present disclosure, as the aforementioned terms may be only used to distinguish one element, component, region, layer, or section from another component, region, layer, or section. Terms such as first, second, third, etc., when used herein do not imply a specific sequence or order unless clearly suggested by the present disclosure.

[0048] It may also be noted that any word expressed either in British or American or Indian English would mean the same. For example, the phrase “fibre” and “fiber” or “colour” and “color” or “soyabean” and “soybean” or “vapour” and “vapor” or “hydrolise” and “hydrolyze” or “flavor” and “flavor” would mean the same for the purpose of the present disclosure.

[0049] Slags such as fly ash, GGBS, pond ash, bottom ash and the like are industrial by-products with pozzolanic potential but are limited in their utility due to irregular particle size, poor surface reactivity, and the presence of unbumt residues. Some particles exceed 100 microns in size, further reducing their effectiveness. Moreover, the disposal of such slags poses environmental concerns related to land use, leaching, and carbon footprint.

[0050] The present disclosure focuses on treating slag particles to impart desirable physical and chemical characteristics using controlled grinding and selective incorporation of additives. This process results in treated slag particles that are optimized for various industrial uses such as construction, soil stabilization, infrastructure, and as composites.

[0051] The present disclosure relates to treated slag particles and a process for the preparation thereof.

[0052] In an aspect of the present disclosure, the treated slag particles comprise additive coated slag particles. In accordance with the present disclosure, the treated slag particles have a particle size in the range of 1 micron to 5 microns and a specific surface area in the range of 40000 m2 / kg to 95000 m2 / kg.

[0053] In an exemplary embodiment, the treated slag particles have the specific surface area of 60000 m / kg. In another exemplary embodiment, the treated slag particles have the specific surface area of 72000 m / kg. In yet another exemplary embodiment, the treated slag particles

[0054] 2 have a specific surface area of 58000 m / kg.

[0055] In accordance with the present disclosure, the additive is at least one selected from the group consisting of calcium, magnesium, silica, alumina, basalt, quartz, china clay, gypsum, kaolin, and calcite. In an embodiment, the additive is a combination of silica and magnesium. In another embodiment, the additive is a combination of silica, magnesium and basalt. In yet another embodiment, the additive is a combination of calcium, magnesium and basalt.

[0056] In accordance with the present disclosure, the additive has a particle size in the range of 1 micron to 4 microns. In accordance with the present disclosure, the slag particles are selected from the group consisting of fly ash, ground granulated blast furnace slag (GGBS), pond ash, bottom ash, and mine ash. In an exemplary embodiment, the slag particles are ground granulated blast furnace slag (GGBS). In another exemplary embodiment, the slag particles are fly ash. In yet another exemplary embodiment, the slag particles are pond ash.

[0057] In accordance with the present disclosure, a predetermined mass ratio of the additive to the slag particles is in the range of 1:9 to 1:99. In an exemplary embodiment, the predetermined mass ratio of the additive to the slag particles is 1: 19. In another exemplary embodiment, the predetermined mass ratio of the additive to the slag particles is 1:9. In still another exemplary embodiment, the predetermined mass ratio of the additive to the slag particles is 1:4.

[0058] In accordance with the present disclosure, the treated slag particles are in a spherical form.

[0059] In an embodiment of the present disclosure, the treated slag particles have uniform morphology.

[0060] In an embodiment of the present disclosure, the treated slag particles have a uniform coating of the additive over the slag particles.

[0061] In accordance with the present disclosure, the treated slag particles have a specific gravity in the range of 2.3 to 3.7.

[0062] In another aspect of the present disclosure, there is provided a process for preparing treated slag particles, the process comprising the following steps: a. obtaining slag particles having predetermined characteristics; b. grinding the slag particles at a predetermined speed for a first predetermined time period to maintain a predetermined temperature during grinding to obtain ground slag particles; c. incorporating an additive to the ground slag particles in a predetermined mass ratio at the predetermined time period for a second predetermined time period to obtain coated slag particles; and d. cooling the coated slag particles to a temperature in the range of 20 °C to 30 °C to obtain the treated slag particles. In accordance with the present disclosure, the additive is at least one selected from the group consisting of calcium, magnesium, silica, alumina, basalt, quartz, china clay, gypsum, kaolin, and calcite.

[0063] In an exemplary embodiment, GGBS particles are coated with a combination of silica and magnesium to obtain treated slag particles of 1 to 2 microns having a spherical shape. In another exemplary embodiment, fly ash particles are coated with calcium, magnesium, and basalt to obtain treated slag particles of 1 to 4 microns having a spherical shape. In still another exemplary embodiment, pond ash particles are coated with silica, magnesium, and basalt to obtain treated slag particles of 1 to 4 microns having a spherical shape.

[0064] In accordance with the present disclosure, the predetermined characteristics of the slag particles are:

[0065] • a particle size is in the range of 10 microns to 100 microns;

[0066] • at least one shape selected from the group consisting of spherical, conical, parabolic, rhomboidal, polyhedral, polygonal and cylindrical; and

[0067] • a specific gravity in the range of 2.3 to 3.7.

[0068] In an embodiment of the present disclosure, the slag particles have an irregular and non- uniform morphology.

[0069] Specific gravity in slag particles is a vital property that impacts their use in diverse applications, especially in production. It suggests the density of the slag relative to water, influencing factors like blend proportions, strength, and sturdiness of concrete or different materials.

[0070] In accordance with the present disclosure, the predetermined speed is in the range of 15 rpm to 40 rpm.

[0071] In accordance with the present disclosure, the first predetermined time period is in the range of 30 minutes to 45 minutes.

[0072] In accordance with the present disclosure, the second predetermined time period is in the range of 10 minutes to 30 minutes.

[0073] In accordance with the present disclosure, the predetermined temperature is in the range of 55 °C to 70 °C. In accordance with the present disclosure, a predetermined mass ratio of the additive to the slag particles is in the range of 1:9 to 1:99. In an exemplary embodiment, the predetermined mass ratio of the additive to the slag particles is 1: 19. In another exemplary embodiment, the predetermined mass ratio of the additive to the slag particles is 1:9. In an exemplary embodiment, the predetermined mass ratio of the additive to the slag particles is 1:4.

[0074] In an embodiment of the present disclosure, the additive is incorporated into the slag particles in a high shear mixer. In accordance with the present disclosure, the high shear mixer facilitates efficient incorporation of the additive onto the slag particles by generating intense shear forces that promotes uniform dispersion, prevent agglomeration, and enhances surface interaction. This results in improved coating or activation of the slag particles.

[0075] In accordance with an embodiment of the present disclosure, the process may optionally include automated temperature and mixing control for improved consistency and scalability in industrial settings.

[0076] In an embodiment of the present disclosure, the treated slag particles have a uniform particle size in the range of 1 micron to 5 microns.

[0077] In an embodiment of the present disclosure, the treated slag particles have a uniform spherical shape with reduced angular friction.

[0078] In an embodiment, at least 80% of the treated slag particles exhibit an exact spherical morphology.

[0079] In accordance with the present disclosure, the treated slag particles obtained from the process

[0080] 2 2 have a specific surface area in the range of 40000 m / kg to 95000 m / kg.

[0081] The treated slag particles exhibit improved properties such as increased surface reactivity, better packing density, and enhanced pozzolanic behaviour suitable for various industrial applications.

[0082] In accordance with the present disclosure, the grinding step not only reduces the particle size of the irregular raw slag particles but also provides a spherical or conical shape and increases the reactive surface area of the slag particles. This step converts uneven particles into cenospheres and plerospheres, thereby, improving their pozzolanic and mechanical properties. In accordance with the present disclosure, the incorporation of additives may be carried out through coating, mixing, or both, and may be designed to enhance specific performance metrics such as retained slump, pumpability, compressive strength, flexural strength, and overall durability of composite formulations where the treated slag is used.

[0083] In accordance with the present disclosure, the treated slag particles are used in various applications, such as, cementitious compositions, road base stabilizers, geopolymeric formulations, soil improvement, and green construction materials.

[0084] In accordance with the present disclosure, the treated slag particles show enhanced bonding behavior due to increased specific surface area, improved interlocking due to uniform size distribution, and reduced angular friction due to spherical or conical geometry.

[0085] In accordance with the present disclosure, the resulting treated slag particles are economically viable and environmentally sustainable, effectively converting otherwise waste materials into value-added products.

[0086] The foregoing description of the embodiments has been provided for purposes of illustration and is not intended to limit the scope of the present disclosure. Individual components of a particular embodiment are generally not limited to that particular embodiment but are interchangeable. Such variations are not to be regarded as a departure from the present disclosure, and all such modifications are considered to be within the scope of the present disclosure.

[0087] The present disclosure is further illustrated herein below with the help of the following experiments. The experiments used herein are intended merely to facilitate an understanding of the ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the experiments should not be construed as limiting the scope of embodiments herein. These experiments can be scaled up to industrial / commercial scale and the results obtained can be extrapolated to industrial / commercial scale.

[0088] EXPERIMENTAL DETAILS:

[0089] Experiment 1: Preparation of the treated slag particles in accordance with the present disclosure: A predetermined amount of slag particles having a particle size in the range of 25 microns to 100 microns, with a specific gravity in the range of 2.3 to 3.5 having a temperature of 27 °C were obtained. The slag particles had irregular and non-uniform morphology. The so obtained slag particles were ground at a speed of 30 rpm for 45 minutes (the temperature of ground slag reached to 55 °C to 70 °C) to obtain ground slag particles. An additive having a particle size in the range of 1 to 4 microns was incorporated into the ground slag particles in a high shear mixer and mixed at a temperature in the range of 55 °C to 70 °C for 20 minutes to obtain coated slag particles. The coated slag particles were cooled to a temperature in the range of 20 °C to 30 °C to obtain the treated slag particles (Experiments 1 to 3). The treated slag particles obtained had uniform and spherical morphology. The size of the treated slag particles was in the range of 1 micron to 5 microns.

[0090] A comparative Experiment (Experiment 4) was used for comparison wherein only GGBS (slag particles) was used without any additives.

[0091] The details of the experiments are provided in Table 1.

[0092] Table 1: Compositions of treated slag particles and their characteristics

[0093] Table 1: Compositions of treated slag particles and their characteristics

[0094] Analysis of Treated and Untreated Slag Particles

[0095] The effect of incorporating treated slag particles (Experiments 1 to 3) into concrete was evaluated and compared with concrete containing untreated slag particles (Experiment 4), and the results obtained are summarized in Table 2. The specific surface area of the treated slag particles was determined in accordance with ASTM D3663, as prescribed by the American Society for Testing and Materials (ASTM). It is evident from Table 2 that the concrete containing the treated slag particles of the present disclosure showed improvements in physical and mechanical properties when compared to concrete containing the untreated particles. As shown in Table 2, the inclusion of treated slag particles provided significantly better particle uniformity, enhanced specific surface area, improved slump retention, and higher compressive strength.

[0096] Table 2: Comparative Performance of concrete containing Treated Slag Particles vs. Untreated Slag Particles

[0097] Concrete containing treated slag particles of the present disclosure exhibits substantially improved slump retention, with values ranging from 180 to 200 mm even after 120 minutes, whereas concrete containing untreated slag particles collapses. This indicates superior workability and prolonged flow behaviour, even after 120 minutes is particularly beneficial in pumping and placement of concrete. Furthermore, the 28-day compressive strength of the treated slag-based concrete mixes exhibited a significant increase as compared to untreated slag-based concrete mixes.

[0098] TECHNICAL ADVANCEMENTS

[0099] The present disclosure described herein above has several technical advantages, including, but not limited to, the realization of, treated slag particles that: • have uniform shape and controlled particle size; • exhibit enhanced specific surface area; and

[0100] • are suitable for diverse industrial use, and, a process for preparing treated slag particles that:

[0101] • enables temperature-controlled grinding and additive coating;

[0102] • reduces waste; and

[0103] • is simple and easy to perform.

[0104] The embodiments herein and the various features and advantageous details thereof are explained with reference to the non-limiting embodiments in the following description. Descriptions of well-known components and processing techniques are omitted so as not to unnecessarily obscure the embodiments herein. The experiments used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the experiments should not be construed as limiting the scope of the embodiments herein.

[0105] The foregoing description of the specific embodiments so fully reveals the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and / or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein. The use of the expression “at least” or “at least one” suggests the use of one or more elements or ingredients or quantities, as the use may be in the embodiment of the disclosure to achieve one or more of the desired objects or results.

[0106] Any discussion of documents, acts, materials, devices, articles, or the like that has been included in this specification is solely for the purpose of providing a context for the disclosure. It is not to be taken as an admission that any or all of these matters form a part of the prior art base or were common general knowledge in the field relevant to the disclosure as it existed anywhere before the priority date of this application.

[0107] The numerical values mentioned for the various physical parameters, dimensions, or quantities are only approximations and it is envisaged that the values higher / lower than the numerical values assigned to the parameters, dimensions or quantities fall within the scope of the disclosure, unless there is a statement in the specification specific to the contrary.

[0108] While considerable emphasis has been placed herein on the components and component parts of the preferred embodiments, it will be appreciated that many embodiments can be made and that many changes can be made in the preferred embodiments without departing from the principles of the disclosure. These and other changes in the preferred embodiment, as well as other embodiments of the disclosure, will be apparent to those skilled in the art from the disclosure herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the disclosure and not as a limitation.

[0109] The foregoing description of the embodiments has been provided for purposes of illustration and is not intended to limit the scope of the present disclosure. Individual components of a particular embodiment are generally not limited to that particular embodiment but are interchangeable. Such variations are not to be regarded as a departure from the present disclosure, and all such modifications are considered to be within the scope of the present disclosure.

[0110] The present disclosure is further illustrated below with the help of the following nonlimiting experiments. The experiments disclosed herein are intended merely to facilitate an understanding of how the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the experiments should not be construed as limiting the scope of embodiments herein. These laboratory-scale experiments can be scaled up to an industrial / commercial scale, and the results obtained can be extrapolated to an industrial / commercial scale.

Claims

Claims:

1. Treated slag particles comprising additive coated slag particles, wherein said treated slag particles are characterized by having:• a particle size in the range of 1 micron to 5 microns; and • a specific surface area in the range of 40000 m / kg to 95000 m / kg.

2. The treated slag particles as claimed in claim 1, wherein said additive is at least one selected from the group consisting of calcium, magnesium, silica, alumina, basalt, quartz, china clay, gypsum, kaolin, and calcite; and said additive has a particle size in the range of 1 micron to 4 microns.

3. The treated slag particles as claimed in claim 1, wherein said slag particles are selected from the group consisting of fly ash, ground granulated blast furnace slag (GGBS), pond ash, mine ash and bottom ash.

4. The treated slag particles as claimed in claim 1, wherein a predetermined mass ratio of said additive to said slag particles is in the range of 1:9 to 1:

99.

5. The treated slag particles as claimed in claim 1, wherein said treated slag particles are in a spherical form.

6. A process for preparing treated slag particles, said process comprising the following steps: a. obtaining slag particles having predetermined characteristics;b. grinding said slag particles at a predetermined speed for a first predetermined time period to maintain a predetermined temperature during grinding to obtain ground slag particles; c. incorporating an additive to said ground slag particles in a predetermined mass ratio at said predetermined temperature for a second predetermined time period to obtain coated slag particles; and d. cooling said coated slag particles to a temperature in the range of 20 °C to 30 °C to obtain said treated slag particles.

7. The process as claimed in claim 6, wherein said additive is at least one selected from the group consisting of calcium, magnesium, silica, alumina, basalt, quartz, china clay, gypsum, kaolin, and calcite.

8. The process as claimed in claim 6, wherein said predetermined characteristics of slag particles are:• a particle size is in the range of 10 microns to 100 microns;• at least one shape selected from the group consisting of spherical, conical, parabolic, rhomboidal, polyhedral, polygonal and cylindrical; and• a specific gravity in the range of 2.3 to 3.7.

9. The process as claimed in claim 6, wherein• said predetermined speed is in the range of 15 rpm to 40 rpm;said first predetermined time period is in the range of 30 minutes to45 minutes;• said second predetermined time period is in the range of 10 minutes to30 minutes; and • said predetermined temperature is in the range of 55 °C to 70 °C.

10. The process as claimed in claim 6, wherein a predetermined mass ratio of said additive to said slag particles is in the range of 1:9 to 1:99.

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