Ceramsite from aluminum salt-based water treatment residuals

Abstract

A process for producing an aluminum salt-based ceramsite (ASC) material from aluminum salt-based water treatment residuals (WTR) is disclosed. The process comprises the steps of: drying and pulverizing the aluminum salt-based WTR into a fine WTR powder; mixing the fine WTR powder with at least one additive to yield a mixture; forming granulated pellets with the mixture; and sintering the granulated pellets at a sintering temperature between about 700 °C and about 1000 °C for a sintering time sufficient to induce expansion and vitrification, thereby obtaining an ASC material exhibiting a porous ceramsite structure and a specific surface area of at least 55 m² / g. The present disclosure further relates to the ASC material produced by the method and to its use in water filtration, landscaping, and construction applications.

Description

CERAMSITE FROM ALUMINUM SALT-BASED WATER TREATMENT RESIDUALS CROSS-REFERENCE

[0001] This PCT application claims the benefit of Canadian Provisional Application No.3,263,116, filed January 23, 2025, which is hereby incorporated by reference in its entirety.TECHNICAL FIELD

[0002] The technical field generally relates to techniques for producing ceramsite for applications in construction, water filtration, and landscaping, and more particularly to processes for producing aluminum salt-based (ASC) ceramsite materials from aluminum salt-based water treatment residuals (WTR).BACKGROUND

[0003] The increasing global demand for clean water has led to widespread reliance on advanced water treatment techniques, including coagulation and flocculation processes. These processes frequently employ aluminum salts to treat water by precipitating and removing impurities. While effective, the use of aluminum salts generates significant quantities of aluminum salt-based water treatment residuals (WTR), a byproduct that poses disposal challenges. WTR are typically composed of hydrated aluminum oxides, silica, and trace amounts of organic and inorganic impurities removed from the treated water. They are classified as a non-hazardous but environmentally persistent waste stream, and their disposal, commonly through landfilling, contributes to long-term environmental concerns.

[0004] Landfilling WTR is not only costly but also environmentally unsustainable. Over time, WTR in landfills can leach contaminants, including trace metals and organic compounds, into surrounding soils and groundwater. Furthermore, the landfilling process fails to harness the potential value of WTR as a resource. Efforts to repurpose WTR have been sporadic and generally limited to applications with minimal added value, such as soil amendments or low-grade fill materials. These approaches do not fully exploit the chemical and physical properties of WTR, leaving a gap in sustainable waste management practices.

[0005] The persistent environmental and economic challenges associated with WTR disposal have driven research into alternative uses for this byproduct. One area of exploration is the development of lightweight aggregate materials, such as ceramsite, using WTR as a primary feedstock. Ceramsite, also known as expanded clay aggregate, is a porous, lightweight material valued for its strength, thermal insulation, and adsorptive properties. It is commonly used in construction, water filtration, and landscaping applications. Transforming WTR into ceramsite offers a dual benefit: mitigating the disposal burden of WTR while creating a high-value product with broad industrial applications.

[0006] Existing methods for ceramsite production rely on mined raw materials such as clay, shale, or slate, which are mined and processed at high energy costs. These methods involve granulating the raw materials into pellets, followed by sintering at elevated temperatures to induce expansion and vitrification. While effective, these processes are resource-intensive and do not address the environmental impact of extracting and processing virgin materials. Incorporating WTR into ceramsite production has the potential to reduce reliance on mined raw materials, lower energy demands, and provide a sustainable solution for utilization of WTR. However, the successful integration of WTR into ceramsite production presents several technical challenges, including the need to optimize the composition of feedstock mixtures, control sintering conditions, and ensure the desired properties of the final product.

[0007] Efforts to use WTR as a component in ceramsite production are documented in prior art, but these attempts have limitations. For instance, conventional techniques often require high proportions of supplementary raw materials, such as clay or sand, to achieve the necessary structural integrity and expansion during sintering. This diminishes the environmental and economic benefits of using WTR as a primary feedstock. Additionally, conventional approaches frequently fail to address the variability in WTR composition, which can affect the consistency and performance of the resulting ceramsite. Without proper formulation and process controls, WTR-derived ceramsite may exhibit inferior strength, porosity, or adsorption capacity, limiting its applicability in demanding industrial uses.

[0008] The demand for innovative approaches to utilize WTR reflects broader commercial opportunities across multiple sectors. The construction industry, for instance,faces growing pressure to adopt sustainable materials that reduce carbon footprints while maintaining performance. Lightweight aggregates such as ceramsite are in high demand for their ability to improve the thermal and mechanical properties of concrete while reducing its weight. Similarly, the water treatment sector requires advanced adsorbent materials with high capacity and efficiency for pollutant removal, particularly in response to stricter regulatory standards for wastewater discharge. The landscaping industry also represents a significant market for durable, moisture-retaining aggregates that enhance soil quality and support sustainable horticulture.

[0009] Accordingly, there remains a need for ceramsite materials and processes addressing limitations of existing ceramsite materials and methods for producing ceramsite materials, or that offer additional advantages in terms of sustainability and waste management and valorization.SUMMARY

[0010] Described herein are processes for producing lightweight, porous aluminum salt-based ceramsite (ASC) materials from aluminum salt-based water treatment residuals (WTR). The processes described herein can transform an environmentally challenging waste product into a valuable material suitable for a wide range of industrial applications. Furthermore, by leveraging WTR as a primary feedstock, the subject matter described herein can address critical environmental concerns while delivering high-performance ceramsite with tailored properties.

[0011] The process comprises drying and pulverizing the aluminum salt-based WTR into a fine WTR powder; mixing the fine WTR powder with at least one additive to yield a mixture; forming granulated pellets with the mixture; and sintering the granulated pellets at a sintering temperature between about 700 °C and about 1000 °C for a sintering time sufficient to induce expansion and vitrification. The ASC material obtained therefrom can have a porous ceramsite structure and a specific surface area of at least 55 m2 / g, and can be used in one or more of water filtration, landscaping, and construction applications.

[0012] More particularly, in accordance with an aspect, there is provided a process for producing an aluminum salt-based ceramsite (ASC) material from a feedstock comprising aluminum salt-based water treatment residuals (WTR), the process comprising:drying and pulverizing the aluminum salt-based WTR into a fine WTR powder;mixing the fine WTR powder with at least one additive to yield a mixture;forming granulated pellets with the mixture; andsintering the granulated pellets at a sintering temperature between about 700 °C and about 1000 °C for a sintering time sufficient to induce expansion and vitrification, thereby forming the ASC material, the ASC material having a porous ceramsite structure and a specific surface area of at least 55 m2 / g.

[0013] In some embodiments, the aluminum salt-based WTR is present in a proportion representing at least 50 wt%, or at least 60 wt%, or at least 70 wt% of the feedstock.

[0014] In some embodiments, the at least one additive comprises at least one clay material.

[0015] In some embodiments, an aluminum salt-based WTR to clay material dry mass ratio is between about 60:40 and about 95:5, or between about 70:30 and about 90:10, or between about 75:25 and about 85:15.

[0016] In some embodiments, the aluminum salt-based WTR to clay material dry mass ratio is between about 75:25 and about 85:15.

[0017] In some embodiments, the aluminum salt-based WTR to clay material dry mass ratio is about 80:20.

[0018] In some embodiments, the process further comprises drying the at least one clay material prior to mixing the fine WTR powder with the at least one clay material.

[0019] In some embodiments, the mixture comprises between about 20 wt% and about 40 wt% of inorganic WTR and between about 40 wt% and about 60 wt% of organic content, or between about 25 wt% and about 35 wt% of inorganic WTR and between about 45 wt% and about 55 wt% of organic content, based on a total dry mixture weight.

[0020] In some embodiments, the mixture comprises between about 35 wt% and about 45 wt% of inorganic WTR and between about 55 wt% and about 65 wt% of organic content, based on a total dry mixture weight.

[0021] In some embodiments, the mixture comprises between about 25 wt% and about 35 wt% of inorganic WTR and between about 45 wt% and about 55 wt% of organic content, based on the total dry mixture weight.

[0022] In some embodiments, drying the aluminum salt-based WTR is performed at a WTR drying temperature between about 20 °C and about 150 °C, or between about 50 °C and about 130 °C, or between about 80 °C and about 120 °C, or between about 90 °C and about 115 °C.

[0023] In some embodiments, drying the aluminum salt-based WTR is performed for a WTR drying time between about 3 h and about 24 h, or between about 6 h and about 18 h, or between about 10 h and about 14 h.

[0024] In some embodiments, drying the aluminum salt-based WTR is performed until the aluminum salt-based WTR exhibits a WTR mass change of less than 0.5 % / h, or less than 0.3 % / h, or less than 0.2 % / h, or less than 0.1 % / h.

[0025] In some embodiments, pulverizing the aluminum salt-based WTR achieves an average fine WTR powder particle size between about 0.02 mm and about 0.30 mm, or between about 0.05 mm and about 0.25 mm, or between about 0.10 mm and about 0.20 mm.

[0026] In some embodiments, forming the mixture into granulated pellets is performed at a granulator spinning speed between about 20 rpm and about 70 rpm, or between about 25 rpm and about 60 rpm, or between about 30 rpm and about 50 rpm.

[0027] In some embodiments, forming the mixture into granulated pellets comprises spraying water or a water-based solution onto the mixture to maintain a mixture moisture level between about 10 wt% and about 50 wt%, or between about 15 wt% and about 40 wt%, or between about 20 wt% and about 35 wt%.

[0028] In some embodiments, the process further comprises drying the granulated pellets prior to the sintering thereof.

[0029] In some embodiments, the granulated pellets are dried at a pellet drying temperature between about 20 °C and about 150 °C, or between about 50 °C and about 130 °C, or between about 80 °C and about 120 °C, or between about 90 °C and about 115

[0030] In some embodiments, the granulated pellets are dried for a pellet drying time between about 3 h and about 24 h, or between about 6 h and about 18 h, or between about 10 h and about 14 h.

[0031] In some embodiments, the process further comprises preheating the granulated pellets prior to the sintering thereof.

[0032] In some embodiments, the granulated pellets are preheated at a preheating temperature between about 250 °C and about 650 °C, or between about 350 °C and about 600 °C, or between about 400 °C and about 550 °C, or between about 450 °C and about 550 °C.

[0033] In some embodiments, the granulated pellets are preheated for a preheating time between about 5 min and about 30 min, or between about 10 min and about 25 min, or between about 15 min and about 25 min.

[0034] In some embodiments, the sintering temperature is between about 750 °C and about 975 °C, or between about 800 °C and about 950 °C, or between about 850 °C and about 950 °C.

[0035] In some embodiments, the sintering temperature is between about 850 °C and about 950 °C.

[0036] In some embodiments, the sintering temperature is about 900 °C.

[0037] In some embodiments, the sintering temperature is achieved at a heating rate between about 3 °C / min and about 30 °C / min, or between about 5 °C / min and about 25 °C / min, or between about 5 °C / min and about 15 °C / min.

[0038] In some embodiments, the sintering time is between about 1 min and about 15 min, or between about 2 min and about 12 min, or between about 3 min and about 10 min, or between about 4 min and about 8 min.

[0039] In some embodiments, sintering the granulated pellets is performed under a controlled atmosphere.

[0040] In some embodiments, the ASC material exhibits a phosphate adsorption capacity of at least 55 mg P / g.

[0041] In some embodiments, the specific surface area of the ASC material is at least 70 m2 / g.

[0042] In some embodiments, the ASC material exhibits a compressive strength suitable for use as a lightweight aggregate in concrete production.

[0043] In some embodiments, the ASC material is configured for use in one or more of water filtration, landscaping, and construction applications.

[0044] In some embodiments,the aluminum salt-based WTR to clay material dry mass ratio is between about 75:25 and about 85:15;the mixture comprises between about 25 wt% and about 35 wt% of inorganic WTR and between about 45 wt% and about 55 wt% of organic content, based on a total dry mixture weight; andthe sintering temperature is between about 850 °C and about 950 °C.

[0045] In some embodiments, the at least one additive comprises at least one silica-rich industrial byproduct.

[0046] In some embodiments, the at least one silica-rich industrial byproduct is at least one of fly ash, glass waste, and slag.

[0047] In some embodiments, the process further comprises one or more features as defined herein and / or described herein and / or illustrated herein.

[0048] In accordance with another aspect, there is provided an aluminum salt-based ceramsite (ASC) material produced according to the process as defined herein, wherein the ASC material has a phosphate adsorption capacity of at least 50 mg P / g.

[0049] In some embodiments, the ASC material comprises residual components derived from the at least one additive.

[0050] In some embodiments, the ASC material further comprises one or more features as defined herein and / or described herein and / or illustrated herein.

[0051] In accordance with yet another aspect, there is provided a sintered aluminum salt-based ceramsite (ASC) material derived from aluminum salt-based water treatment residuals (WTR) having a porous structure having a specific surface area of at least 55 m2 / g and a phosphate adsorption capacity of at least 50 mg P / g, the ASC material comprising residual components derived from at least one additive of a feedstock used to produce the sintered ASC material.

[0052] In some embodiments, the feedstock comprises at least 50 wt% aluminum saltbased WTR, or at least 60 wt% aluminum salt-based WTR, or at least 70 wt% aluminum salt-based WTR.

[0053] In some embodiments, the at least one additive comprises at least one clay material.

[0054] In some embodiments, the feedstock has an aluminum salt-based WTR to clay material dry mass ratio between about 60:40 and about 95:5, or between about 70:30 and about 90:10, or between about 75:25 and about 85:15.

[0055] In some embodiments, the sintered ASC material is produced via a sintering step performed at a sintering temperature between about 700 °C and about 1000 °C, or between about 750 °C and about 975 °C, or between about 800 °C and about 950 °C, or between about 850 °C and about 950 °C.

[0056] In some embodiments, the sintering temperature is between about 850 °C and about 950 °C.

[0057] In some embodiments, the specific surface area of the ASC material is at least 70 m2 / g.

[0058] In some embodiments, the sintered ASC material has a compressive strength suitable for use as a lightweight aggregate in concrete applications.

[0059] In some embodiments, the sintered ASC material is suitable for use as a high-performance adsorbent in water filtration applications.

[0060] In some embodiments, the sintered ASC material is suitable for use as a moisture and nutrient retention aid in landscaping and horticulture applications.

[0061] In some embodiments, the at least one additive comprises at least one silica-rich industrial byproduct.

[0062] In some embodiments, the sintered ASC material further comprises one or more features as defined herein and / or described herein and / or illustrated herein.BRIEF DESCRIPTION OF THE DRAWINGS

[0063] Embodiments of the process for producing aluminum salt-based ceramsite (ASC) materials from aluminum salt-based water treatment residuals (WTR) and the resulting ASC materials, and associated applications are represented in, and will be further understood in connection with the following figures.

[0064] Fig 1 is a flow diagram of a process for producing aluminum salt-based ceramsite (ASC) materials from aluminum salt-based water treatment residuals (WTR), in accordance with an embodiment of the present disclosure.

[0065] Fig 2 illustrates the impact of various process parameters on a resulting specific surface area of an ASC material produced. The process parameters are aluminum saltbased WTR to clay material dry mass ratio (in wt%, identified C1), preheating time (in minutes, identified C2), preheating temperature (in °C, identified C3), sintering time (in minutes, identified C4), sintering temperature (in °C, identified C5), and heating rate (in °C / minutes, identified C6).DETAILED DESCRIPTION

[0066] While the present techniques will be described in conjunction with example embodiments, it will be understood that it is not intended to limit the scope of the invention to such embodiments. On the contrary, it is intended to cover all alternatives, modifications and equivalents as may be included as defined by the present description. The objects, advantages and other features of the present invention will become more apparent and be better understood upon reading of the following non-restrictive description of the invention, given with reference to the accompanying drawings.

[0067] All technical and scientific terms and expressions used herein have the same definitions as those commonly understood by the person skilled in the art when relating to the present technology. The definition of some terms and expressions used herein is nevertheless provided below for clarity purposes.

[0068] When the term “about” is used herein, it means approximately, in the region of or around. When the term “about” is used in relation to a numerical value, it modifies it, for example, by a variation of 10% above and below its nominal value. This term can also take into account the rounding of a number or the probability of random errors in experimental measurements, for instance, due to equipment limitations.

[0069] When a range of values is mentioned herein, the lower and upper limits of the range are, unless otherwise indicated, always included in the definition. When a range of values is mentioned in the present application, then all intermediate ranges and subranges, as well as individual values included in the ranges, are intended to be included.

[0070] It is worth mentioning that throughout the following description when the article “a” is used to introduce an element, it does not have the meaning of “only one” and rather means “one or more”. It is to be understood that where the specification states that a step, component, feature, or characteristic “may”, “might”, “can” or “could” be included, that particular component, feature, or characteristic is not required to be included in all alternatives.

[0071] In the present description, an embodiment is related to an example or optional feature. The various appearances of “one embodiment,” “an embodiment” or “some embodiments” do not necessarily all refer to the same embodiments. Although various features of the invention may be described in the context of a single embodiment, the features may also be provided separately or in any suitable combination. Conversely, although the invention may be described herein in the context of separate embodiments for clarity, the invention may also be implemented in a single embodiment.

[0072] When the article “a” or “an” is used to introduce an element in the present application, it should not be understood in a limiting sense as “only one”, but rather as “one or more”. It should be understood that where the description states that a particular step, component, element, or feature “may” or “can” be included, such step, component, element, or feature is not required to be present in every embodiment.

[0073] The present application generally pertains to processes for producing lightweight, porous aluminum salt-based ceramsite (ASC) materials using aluminum saltbased water treatment residuals (WTR) as the primary feedstock. The present application further relates to the ASC material produced by the processes described herein and to their use for instance in water filtration, landscaping, and construction applications.

[0074] In particular, there is provided a process for producing an ASC material from a feedstock comprising aluminum salt-based WTR, the process comprising:drying and pulverizing the aluminum salt-based WTR into a fine WTR powder;mixing the fine WTR powder with at least one additive to yield a mixture;forming granulated pellets with the mixture; andsintering the granulated pellets at a sintering temperature between about 700 °C and about 1000 °C for a sintering time sufficient to induce expansion and vitrification, thereby forming the ASC material, wherein the ASC material exhibits a porous ceramsite structure and a specific surface area of at least 55 m2 / g.

[0075] The applications mentioned above in water filtration, landscaping, and construction can make use of the ASC material produced by the processes described herein, owing to their resulting porous structure, high specific surface area and mechanical integrity.

[0076] Without being bound by theory, the porous structure of the ASC material described herein can promote efficient mass transfer and provide abundant active sites for adsorption, making these materials particularly suitable for water filtration and treatment applications, where the removal of pollutants such as phosphate and heavy metals is required. In landscaping applications, the ASC material described herein can serve as durable, moisture- and nutrients-retaining aggregates that enhance soil quality and supports sustainable horticulture practices. The high specific surface area of the ASC material described herein can enable capillary storage of water, which can result in a subsequent gradual release of water to surrounding soil and plant roots, thereby improving water-use efficiency. In addition, the adsorption capacity of the ASC material described herein can support the temporary retention of nutrients, reducing nutrient leaching andenhancing nutrient availability overtime. In construction applications, the ASC material as described herein can function as lightweight aggregates that improve the thermal insulation and mechanical properties, such as compressive strength, of concrete while reducing its weight.

[0077] The porous structure and properties of ASC material described herein are closely related to their production process. Without being bound by theory, ceramsite materials production involves pore formation and vitrification, which occur through a coupled thermal decomposition and liquid phase sintering mechanism. During thermal processing, an organic fraction present in the raw material decomposes and volatilizes, thereby generating gaseous species that nucleate within individual granules. As the temperature increases, a liquid phase can form as a result of flux components such as alkali oxides, alkaline earth oxides, and iron oxides, and the viscosity of the liquid or glass phase governs whether the generated gases are able to escape or are retained within the granules.

[0078] When the viscosity of the liquid phase and the rate of gas evolution are suitably balanced, the gases become entrapped as discrete pores, resulting in a stable porous structure with increased pore volume and specific surface area. If the extent of liquid phase formation is insufficient, for example due to an inadequately low sintering temperature or an insufficient amount of flux material, the gaseous species are not effectively stabilized, particle coalescence is limited, and the resulting structure exhibits poordensification, weak interparticle bonding, and reduced mechanical strength. Conversely, if the liquid phase becomes excessively fluid, such as under conditions of excessive flux content or overly high sintering temperature, the gaseous bubbles may coalesce and escape or the structure may undergo excessive vitrification and densification, leading to partial or complete pore collapse and a reduction in accessible surface area, even though compressive strength may increase.

[0079] Organic content of the feedstock used to produce the ASC material as described herein can also play an important role in establishing the final pore structure. A minimum amount of organic matter may be required to generate sufficient gas for pore creation, and an organic content below this level may result in limited porosity and a low specific surface area. In contrast, an excessive organic content may generate high internal gas pressures during thermal decomposition, potentially causing uncontrolled expansion,coalescence of pores, thinning of pore walls, and a consequent reduction in mechanical strength or structural integrity. Accordingly, depending on the intended application of a ceramsite material, an optimal range of organic content can exist in which sufficient gas is generated to form a porous structure while maintaining adequate wall thickness and compressive strength.

[0080] Sintering temperature, sintering time, and heating rate can collectively influence the degree of vitrification and the resulting balance between porosity and strength of the ASC material. Sintering at temperatures that are too low, or for insufficient durations, may leave the material under vitrified, with weak particle bonding and limited mechanical strength despite the presence of pores. Sintering at excessively high temperatures, or for overly long sintering times, may promote extensive viscous flow and densification, thereby closing pores and reducing specific surface area and adsorption capacity. Heating profiles that allow controlled burn out of organic matter prior to or during vitrification are believed to favor the formation of a more uniform and stable pore structure.

[0081] Accordingly, techniques known in the art for producing ceramsite materials are often confronted with challenges in simultaneously balancing the above-mentioned considerations and supporting more efficient, robust, and sustainable production practices.

[0082] For a more detailed understanding of the disclosure, reference is now made to Fig 1 , illustrating a process flow diagram of an embodiment of a process 100 for producing an aluminum salt-based ceramsite (ASC) material from aluminum salt-based water treatment residuals (WTR). It is to be noted that boxes delineated by solid lines correspond to steps typically performed in the process, whereas boxes delineated by dashed lines should be interpreted as including optional steps. The connecting arrows, whether solid or dashed, reflect the same coding convention.

[0083] In some embodiments, the process 100 for producing an aluminum salt-based ceramsite (ASC) material from a feedstock comprising aluminum salt-based water treatment residuals (WTR) can include drying and pulverizing the aluminum salt-based WTR into a fine WTR powder 110.

[0084] In some embodiments, the aluminum salt-based ceramsite WTR can be present in a proportion representing at least 50 wt%, or at least 60 wt%, or at least 70 wt%of the feedstock. A mass percentage of aluminum salt-based WTR can ensure a high utilization rate of this waste material while maintaining the performance characteristics of the ASC material.

[0085] In some embodiments, the aluminum salt-based WTR can have a water content ranging between 25 wt% and 90 wt% and be characterized by a broad range of particle sizes. Accordingly, drying and pulverizing this raw material can contribute to ensuring uniformity in the feedstock, in terms of moisture content and particle size distribution, enabling consistent results during subsequent process steps.

[0086] In some embodiments, the aluminum salt-based WTR can be dried for instance in a drying oven, in a vacuum chamber, or under ambient air. In some embodiments, the aluminum salt-based WTR can be dried at a WTR drying temperature between about 20 °C and about 150 °C, or between about 50 °C and about 130 °C, or between about 80 °C and about 120 °C, or between about 90 °C and about 115 °C. In some embodiments, the aluminum salt-based WTR can be dried for a WTR drying time between about 3 h and about 24 h, or between about 6 h and about 18 h, or between about 10 h and about 14 h. In some embodiments, the aluminum salt-based WTR can be dried until it exhibits a WTR mass change of less than 0.5 % / h, or less than 0.3 % / h, or less than 0.2 % / h, or less than 0.1 % / h. In an example, the aluminum salt-based WTR can be dried in a drying oven, at 100 °C, for 14 h.

[0087] In some embodiments, the aluminum salt-based WTR can be pulverized using a method selected from the group consisting of ball milling, hammer milling, jet milling, disc or plate milling, roller milling, and a combination thereof. In some embodiments, the aluminum salt-based WTR can be pulverized to achieve an average fine WTR powder particle size between about 0.02 mm and about 0.30 mm, or between about 0.05 mm and about 0.25 mm, or between about 0.10 mm and about 0.20 mm. In some embodiments, the aluminum salt-based WTR can be pulverized so that the resulting fine WTR powder passes through a 40-mesh, 60-mesh, 80-mesh, or 100-mesh sieve. In an example, the aluminum salt-based WTR can be pulverized to achieve an average fine WTR powder particle size of 0.15 mm.

[0088] Still referring to Fig 1, the process 100 further includes mixing the fine WTR powder with the at least one additive to yield a mixture 120. In some embodiments, the atleast one additive can include at least one clay material. This aspect will be described in further detail below. In some embodiments, the mixing can be performed for instance using a method selected from the group consisting of dry blending, high-shear mixing, mechanical vibration or shaking, wet mixing with a liquid binder followed by drying, or a combination thereof. In some embodiments, the at least one additive can include at least one clay material.

[0089] In some embodiments, the mixture can include between about 20 wt% and about 40 wt% of inorganic WTR and between about 40 wt% and about 60 wt% of organic content, or between about 25 wt% and about 35 wt% of inorganic WTR and between about 45 wt% and about 55 wt% of organic content, based on a total dry mixture weight. In an example, the mixture can include about 27 wt% of inorganic WTR and about 58 wt% of organic content, based on a total dry mixture weight. In another example, the mixture can include about 30 wt% of inorganic WTR and about 50 wt% of organic content, based on a total dry mixture weight. In some embodiments, the feedstock can include one or more of AI2O3, SiC>2, Fe2C>3, MgO, CaO, K2O / Na2O, and P2O5, and organic content. In some embodiments, the feedstock can include AI2O3, SiC>2, Fe2Os, MgO, CaO, K2O / Na2O, and P2O5 and organic content.

[0090] In some embodiments, the feedstock can have an aluminum salt-based WTR to clay material dry mass ratio between about 60:40 and about 95:5, or between about 70:30 and about 90:10, or between about 75:25 and about 85:15. It is to be understood that the stated dry mass ratio refers to the respective masses of the aluminum salt-based WTR and the clay material on a dry basis, excluding water content. In an example, the aluminum salt-based WTR and the at least one clay material in the feedstock can be characterized by an aluminum salt-based WTR to clay material dry mass ratio of about 80:20. The at least one clay material can generally act as a binder and structural agent, contributing to the mechanical integrity and expansion potential of the granulated pellets during sintering.

[0091] In some embodiments, the clay material comprises bentonite. In some embodiments, the clay material is bentonite. Bentonite can provide benefits in the production of the ASC material described herein, such as facilitating the formation of granulated pellets, promoting internal expansion during sintering, and enhancing internal porosity.

[0092] In some embodiments, the at least one clay material can also be subjected to a drying and pulverizing step prior to being mixed with the fine WTR powder. In some embodiments, the at least one clay material can be dried and pulverized under similar conditions to those used for the aluminum salt-based WTR. In some embodiments, the aluminum salt-based WTR and the at least one clay material can be dried and pulverized together. In the context of the disclosure, it is to be understood that the terms "pulverizing" and "grinding" are used interchangeably to refer to a step of reducing a material to a fine powder. It is also to be understood that when referring to “drying” in the context of the step of “drying and pulverizing the aluminum salt-based WTR into a fine WTR powder”, it is intended to mean that a moisture content is reduced, and does not necessarily mean that the moisture content is brought to zero. In some embodiments, there can thus be a residual moisture content following the drying step.

[0093] In some embodiments, the at least one additive can include at least one silica-rich industrial byproduct. A silica-rich industrial byproduct can provide supplementary silica and alumina, which can contribute to the structural and thermal properties of the ASC material. In some embodiments, the at least one additive can consist of the at least one silica-rich industrial byproduct when said silica-rich industrial byproduct exhibits mineral characteristics similar to those of a clay material. In some embodiments, the mixture can thus include fine WTR powder and at least one clay material. In other embodiments, the mixture can include fine WTR powder and at least one silica-rich industrial byproduct. In yet other embodiments, the mixture can include fine WTR powder, at least one clay material, and at least one silica-rich industrial byproduct. It is to be understood that, in embodiments where the mixture includes fine WTR powder, at least one clay material, and at least one silica-rich industrial byproduct, the order in which the components are mixed to form the mixture is not limiting. In one example, the mixing can be achieved by first combining the fine WTR powder with the at least one clay material, followed by mixing with the at least one silica-rich industrial byproduct. In another example, the fine WTR powder can be first mixed with the at least one silica-rich industrial byproduct, followed by mixing with the at least one clay material. In yet another example, the at least one clay material can be first mixed with the at least one silica-rich industrial byproduct, followed by mixing with the fine WTR powder. In some embodiments, the at least one silica-rich industrial byproduct can be selected from fly ash, glass waste, and slag. It is to be understood that, similarly to the at least one clay material, the at least one silica-richindustrial byproduct, if present, can be subjected to ancillary pretreatment steps including drying and pulverizing prior to being mixed. The at least one clay material and / or the at least one silica-rich industrial byproduct can generally contribute to providing structural integrity, enhanced sintering performance, and can thus contribute to the desired physical and chemical properties of the resulting ASC material. The proportions of the fine WTR powder, the at least one clay material, and the at least one silica-rich industrial byproduct, can generally be adjusted to achieve a desired balance of porosity, strength, and adsorption capacity in the resulting ASC material.

[0094] As depicted in Fig 1, the process further includes forming granulated pellets with the mixture 130. The granulation can be performed using conventional methods such as extrusion or pelletization, depending on factors such as the target application and the production scale. In some embodiments, the formation of granulated pellets can be performed at a granulator spinning speed between about 20 rpm and about 70 rpm, or between about 25 rpm and about 60 rpm, or between about 30 rpm and about 50 rpm. In some embodiments, the formation of granulated pellets can be performed in the presence of one or more organic or inorganic binder. An organic or inorganic binder can enhance the cohesion and durability of the granulated pellets during subsequent handling and facilitate controlled expansion during the sintering step. In some embodiments, the formation of granulated pellets can include spraying water or a water-based solution onto the mixture to maintain a mixture moisture level between about 10 wt% and about 50 wt%, or between about 15 wt% and about 40 wt%, or between about 20 wt% and about 35 wt%. In an example, the formation of granulated pellets can be performed at a granulator spinning speed of about 35 rpm, in the presence of sprayed water. In some embodiments, the granulated pellets can be dried prior to their sintering. Techniques for drying the granulated pellets can include air-drying or the granulated pellets can be subjected to heating to remove residual moisture and reduce the risk of thermal shock during the sintering process. In some embodiments, the granulated pellets can be heated at a pellet drying temperature between about 20 °C and about 150 °C, or between about 50 °C and about 130 °C, or between about 80 °C and about 120 °C, or between about 90 °C and about 115 °C. In some embodiments, the granulated pellets can be dried for a pellet drying time between about 3 h and about 24 h, or between about 6 h and about 18 h, or between about 10 h and about 14 h. In some embodiments, forming granulated pellets of uniformsize and shape may be desirable. Uniformity in pellet size and shape can contribute to ensuring consistent sintering and material properties in the ASC material.

[0095] Still referring to Fig 1, the process further includes sintering the granulated pellets at a sintering temperature between about 700 °C and about 1000 °C for a sintering time sufficient to induce expansion and vitrification, so as to form the ASC material, wherein the ASC material exhibits a porous ceramsite structure and a specific surface area of at least 55 m2 / g 140. In some embodiments, sintering the granulated pellets can be performed for instance in a kiln or a muffle furnace. In some embodiments, the temperature range of about 700 °C and about 1000 °C enables achieving the dual objectives of expansion and vitrification, which impart the ceramsite with its characteristic porous structure and durability. In some embodiments, the sintering temperature can be between about 750 °C and about 975 °C, or between about 800 °C and about 950 °C, or between about 850 °C and about 950 °C. In a preferred embodiment, the sintering temperature can be between about 850 °C and about 950 °C. In some embodiments, the sintering of the granulated pellets can allow for a complete vitrification of silica and alumina components. Surprisingly, it was found that there was an increase in the specific surface area (SSA) of the ASC material produced at lower sintering temperatures, which is counter-intuitive in the general context of ceramsite production from sludge such as aluminum salt-based WTR, which are produced at sintering temperatures higher than 1000 °C. It is to be understood that other process parameters have to be controlled in order to achieve this effect, such as those described for instance in the Examples 1 and 2 below.

[0096] In that respect, reference is now made to Fig 2, which illustrates various process parameters that have been varied to identify optimized conditions for the process when it is desired to enhance the resulting specific surface area of the ASC material produced. Fig 2 illustrates an inverse relationship between the sintering temperature and the resulting specific surface area, with the highest specific surface area being achieved at the lowest sintering temperature tested. Conversely, Fig 2 also indicates that a higher aluminum salt-based WTR to clay material dry mass ratio (for instance, 80:20 vs. 40:60) resulted in a higher specific surface area.

[0097] In some embodiments, the sintering temperature can be achieved at a heating rate between about 3 °C / min and about 30 °C / min, or between about 5 °C / min and about25 °C / min, or between about 5 °C / min and about 15 °C / min. In some embodiments, the sintering time, corresponding to the time during which the sintering temperature is applied to the granulated pellets, can be between about 1 min and about 15 min, or between about 2 min and about 12 min, or between about 3 min and about 10 min, or between about 4 min and about 8 min. The sintering time can vary according to the composition of the feedstock and desired product properties In an example, the granulated pellets can be sintered at a sintering temperature of about 900 °C for a sintering time of about 5 minutes, with the sintering temperature being achieved by applying a heating rate of about 10 °C / min. It is thus to be understood that sintering the granulated pellets involves a controlled heating profile to gradually heat the granulated pellets and avoid rapid thermal gradients that could compromise their structural integrity.

[0098] In some embodiments, sintering the granulated pellets can be performed under a controlled atmosphere. Atmospheric conditions within the kiln or muffle furnace can be carefully regulated to optimize the properties of the ASC material. For instance, oxygen levels can be controlled to influence the oxidation states of certain components, which can affect the porosity and adsorption characteristics of the ASC material. The kiln or muffle furnace atmosphere can also be adjusted to minimize energy consumption and emissions, in alignment with the sustainable objectives of the invention.

[0099] In some embodiments, sintering the granulated pellets can further include preheating the granulated pellets prior to reaching the sintering temperature. In some embodiments, the preheating can be achieved at a substantially constant temperature in the muffle furnace. In some embodiments, the granulated pellets can be preheated at a preheating temperature between about 250 °C and about 650 °C, or between about 350 °C and about 600 °C, or between about 400 °C and about 550 °C, or between about 450 °C and about 550 °C. In some embodiments, the granulated pellets can be preheated for a preheating time between about 5 min and about 30 min, or between about 10 min and about 25 min, or between about 15 min and about 25 min. In an example, the preheating of the granulated pellets can be performed for a preheating time of about 20 minutes at a preheating temperature of about 500 °C.

[0100] In some embodiments, a subsequent step of waste heat recovery can be integrated to the process described herein to capture and reuse energy, thereby reducing environmental impact.

[0101] In some embodiments, the ASC material resulting from the above-described process can have a phosphate adsorption capacity of at least 50 mg P / g. In an example, the ASC material can have a specific surface area of about 70 m2 / g and a phosphate adsorption capacity of about 47 mg P / g, for instance. In some embodiments, the ASC material can have a compressive strength suitable for use as a lightweight aggregate in concrete production. In some embodiments, the ASC material can be used in one or more of water filtration, landscaping, and construction applications.

[0102] In some embodiments, the process parameters associated with the process for producing an ASC material from aluminum salt-based WTR disclosed herein can be optimized simultaneously to achieve the desired properties of the resulting ASC material. The process parameters of the process described herein can thus be viewed as a holistically constrained, multi-parameter fabrication regime in which a raw material composition (organic-rich aluminum-salt WTR with an additive, such as a clay material), moisture, particle size, preheating conditions, and sintering schedule are jointly controlled to yield a high-SSA, highly porous ASC material that can be suitable for filtration and phosphate adsorption, for instance.

[0103] In some embodiments, the process for producing an ASC material from a feedstock comprising aluminum salt-based WTR as defined herein can present at least one of the following benefits:High WTR utilization: By incorporating at least 50% of aluminum salt-based WTR by weight, the process can enhance the use of this waste stream while maintaining product performance.Tailored properties: The process can allow for precise control of the porosity, strength, and adsorption capacity of the ASC material, enabling its use in demanding applications.Resource efficiency: The inclusion of industrial byproducts can reduce reliance on virgin raw materials, lowering the environmental impact of the production process.Cost -effectiveness: The high utilization of waste materials and energy-efficient sintering process can contribute to reduced production costs.

[0104] The process described herein for producing an ASC material thus provides an innovative solution for repurposing WTR. By converting an environmentally challenging waste stream into a high-value material, the present disclosure addresses critical environmental and industrial challenges while delivering economic and ecological benefits.Characteristics, properties, and applications of the ASC material

[0105] The present disclosure further relates to a sintered ASC material produced from a feedstock comprising aluminum salt-based WTR and to its use in water filtration, landscaping, and construction applications. In particular, there is provided a sintered aluminum salt-based ceramsite (ASC) material derived from aluminum salt-based water treatment residuals (WTR) having a porous structure having a specific surface area of at least 55 m2 / g; a phosphate adsorption capacity of at least 50 mg P / g, the ASC material comprising residual components derived from at least one additive of a feedstock used to produce the sintered ASC material. In some embodiments, the at least one additive can include at least one clay material, at least one silica-rich industrial byproduct, or both.

[0106] In some embodiments, the feedstock can include at least 50 wt% aluminum salt-based WTR, or at least 60 wt% aluminum salt-based WTR, or at least 70 wt% aluminum salt-based WTR. In some embodiments, the feedstock can have an aluminum salt-based WTR to clay material dry mass ratio between about 60:40 and about 95:5, or between about 70:30 and about 90:10, or between about 75:25 and about 85:15. In embodiments where the sintered ASC material is produced from a feedstock comprising at least one silica-rich industrial byproduct in accordance with the process described herein, the sintered ASC material can further include residual components derived from the at least one silica-rich industrial byproduct. In some embodiments, the sintered ASC material can result from a sintering step performed at a sintering temperature between about 700 °C and about 1000 °C, or between about 750 °C and about 975 °C, or between about 800 °C and about 950 °C, or between about 850 °C and about 950 °C.

[0107] In some embodiments, the sintered ASC material can have a specific surface area of at least 70 m2 / g. In some embodiments, the sintered ASC material can have a compressive strength suitable for use as a lightweight aggregate in concrete applications. In some embodiments, the sintered ASC material can be suitable for use as a high-performance adsorbent in water filtration applications. In some embodiments, the sintered ASC material can be suitable for use as a moisture and nutrient retention aid in landscaping and horticulture applications.

[0108] It is to be understood that the specific surface area, the phosphate adsorption capacity as well as desired mechanical properties can be achieved through precise control of the feedstock composition and sintering conditions.

[0109] In some embodiments, the ASC material as defined herein can be characterized by at least one of the following:Porosity and surface area: The ASC material can have a specific surface area greater than 55 m2 / g, making it effective as an adsorbent for pollutants such as phosphates and heavy metals in water treatment applications.Phosphate adsorption capacity: The ASC material can achieve a phosphate adsorption capacity of at least 50 mg P / g, which can outperform conventional adsorbents.Compressive strength: The ASC material can demonstrate sufficient compressive strength for use as a lightweight aggregate in concrete production, contributing to improved thermal insulation and mechanical properties of concrete structures.Moisture Retention: In landscaping applications, the ASC material can retain moisture and nutrients, enhancing soil quality and supporting plant growth.

[0110] In some embodiments, the ASC material as defined herein can be considered for application in the following fields:Water Treatment: The high adsorption capacity and specific surface area of the ASC material make them ideal for removing pollutants from industrial and municipal wastewater. Their lightweight nature simplifies handling and integration into existing filtration systems.Construction: As lightweight aggregates, the ASC material reduce the density of concrete required while improving the thermal and acoustic insulation propertiesthereof, making them suitable for integration in high-rise buildings and specialized infrastructure.Landscaping: The ability of the ASC material to retain moisture and nutrients enhances soil aeration and plant health. The ASC material can thus serve as durable, eco-friendly alternatives to traditional mulches.Sustainability considerations

[0111] The present disclosure incorporates principles of sustainability by utilizing waste materials as feedstock. The high aluminum salt-based WTR content in the feedstock reduces reliance on virgin raw materials, contributing to the circular economy. Silica-rich industrial byproducts such as fly ash, waste glass, and slag further enhance sustainability by diverting industrial byproducts from landfills.

[0112] Furthermore, the sintering step is designed for energy efficiency, employing optimized kiln and muffle furnace designs and optionally integrating heat recovery pathways to minimize energy consumption and emissions. These features align the process described herein and the resulting ASC material with global objectives for decarbonization and sustainable resource management.

[0113] The present disclosure thus represents a comprehensive approach to waste valorization, leveraging advanced material engineering to create sustainable, high-value products.EXAMPLES

[0114] The following examples are provided for illustrative purposes only and should not be interpreted as further limiting the scope of the invention as contemplated.

[0115] Unless otherwise indicated, all numerical values expressing quantities of components, preparation conditions, concentrations, properties, and the like as used herein are to be understood as being modified in all instances by the term “about”. At a minimum, each numerical parameter should be interpreted in light of the number of significant figures reported and by applying common rounding techniques. Accordingly, unless otherwise indicated, the numerical parameters set forth in this document are approximations that may vary depending on the desired properties. Notwithstanding thatthe ranges of numerical values and the parameters defining the scope of the embodiments are approximations, the numerical values presented in the following examples are reported as precisely as possible. However, any numerical value inherently contains certain errors arising from variations in experiments, test measurements, statistical analyses, and the like.Example 1Preparation of an aluminum salt-based ceramsite (ASC) material from a feedstock comprising aluminum salt-based water treatment residuals (WTR).

[0116] To produce an ASC material from a feedstock comprising aluminum salt-based WTR, the aluminum salt-based WTR was dried at 105 °C for 12 h in a drying oven, then ground to produce a fine WTR powder sized to pass through a 100-mesh sieve (i.e., -0.15 mm).

[0117] A clay material corresponding to bentonite was also dried at 105 °C for 12 h, then ground into a bentonite powder sized to pass through a 100-mesh sieve (i.e., - 0.15 mm).

[0118] The fine WTR powder and the bentonite powder were mixed to form a mixture having an aluminum salt-based WTR to clay material dry mass ratio of about 80:20. In this particular example, the mixture included about 30% of inorganic WTR and about 50 wt% of organic content.

[0119] Granulated pellets were then formed using the mixture, and water was sprayed onto the mixture during pelletization to maintain a moisture content between about 20 wt% and 35 wt%. The granulated pellets were subsequently dried in the drying oven at a pellet heating temperature of 105 °C for a pellet drying time of 12 h to produce dried granulated pellets.

[0120] The dried granulated pellets were then introduced into a kiln and subjected to sintering. In order to do so, the granulated pellets were first preheated at a preheating temperature of 500 °C for a preheating time of 20 min. Following preheating, the granulated pellets were sintered at a sintering temperature of 900 °C for a sintering timeof 5 min. Throughout the sintering of the granulated pellets, a heating rate of 10 °C / min was maintained.

[0121] Once the sintering step was completed, the resulting ASC material was allowed to cool prior to characterization.

[0122] The specific surface area of the ASC material, as determined using the BET (Brunauer-Emmett-Teller) method, was 70.529 m2 / g.Example 2Preparation of an aluminum salt-based ceramsite (ASC) material from a feedstock comprising aluminum salt-based water treatment residuals (WTR).

[0123] To produce a comparative ceramsite material from a feedstock comprising aluminum salt-based WTR, the aluminum salt-based WTR was dried at 105 °C for 12 h, then ground to produce a fine WTR powder sized to pass through a 100-mesh sieve (i.e., - 0.15 mm). A clay material corresponding to bentonite was also dried at 105 °C for 12 h, then ground into a bentonite powder sized to pass through a 100-mesh sieve (i.e., - 0.15 mm). These conditions are thus the same conditions as those described with reference to Example 1.

[0124] The fine WTR powder and the bentonite powder were mixed to form a mixture having an aluminum salt-based WTR to clay material dry mass ratio of about 80:20. These conditions are thus the same conditions as those described with reference to Example 1.

[0125] Granulated pellets were then formed using the mixture, and water was sprayed onto the mixture during pelletization. The granulated pellets were subsequently dried in the drying oven at a pellet heating temperature of 105 °C for a pellet drying time of 12 h to produce dried granulated pellets. These conditions are thus the same conditions as those described with reference to Example 1.

[0126] The dried granulated pellets were then subjected to preheating under the same conditions as in Example 1, but were then sintered at a sintering temperature of 1100 °C for a sintering time of 5 min. Throughout the sintering of the granulated pellets, a heating rate of 8 °C / min was maintained.

[0127] Once the sintering step was completed, the resulting ASC material was allowed to cool in the kiln under the same conditions as in Example 1, prior to characterization.

[0128] The specific surface area of the ASC material, as determined using the BET (Brunauer-Emmett-Teller) method, was 46.631 m2 / g.

[0129] The above result shows that an increase in sintering temperature above the sintering temperature range of about 700 °C to about 1000 °C can negatively affect the resulting specific surface area by causing a reduction in the specific surface area of the ASC material of more than 30 %, while other process parameters are maintained as described in Example 1.

[0130] It will be apparent to those of skill in the art that by routine modification the present invention can be optimized for use in a wide range of conditions and application. It will also be obvious to those of skill in the art that there are various ways and designs with which to produce the apparatus and methods of the present invention. The illustrated embodiments are therefore not intended to limit the scope of the invention, but to provide examples of the apparatus and method to enable those of skill in the art to appreciate the inventive concept.

[0131] Those skilled in the art will recognize that many more modifications besides those already described are possible without departing from the inventive concepts herein. The inventive subject matter, therefore, is not to be restricted except in the scope of the appended claims. Moreover, in interpreting both the specification and the claims, all terms should be interpreted in the broadest possible manner consistent with the context. The terms "comprises" and "comprising" should be interpreted as referring to elements, components, or steps in a non-exclusive manner, indicating that the referenced elements, components, or steps may be present, or utilized, or combined with other elements, components, or steps not expressly referenced.

Claims

CLAIMS1. A process for producing an aluminum salt-based ceramsite (ASC) material from a feedstock comprising aluminum salt-based water treatment residuals (WTR), the process comprising:drying and pulverizing the aluminum salt-based WTR into a fine WTR powder;mixing the fine WTR powder with at least one additive to yield a mixture;forming granulated pellets with the mixture; andsintering the granulated pellets at a sintering temperature between about 700 °C and about 1000 °C for a sintering time sufficient to induce expansion and vitrification, thereby forming the ASC material, the ASC material having a porous ceramsite structure and a specific surface area of at least 55 m2 / g.

2. The process of claim 1, wherein the aluminum salt-based WTR is present in a proportion representing at least 50 wt%, or at least 60 wt%, or at least 70 wt% of the feedstock.

3. The process of claim 1 or 2, wherein the at least one additive comprises at least one clay material.

4. The process of claim 3, wherein an aluminum salt-based WTR to clay material dry mass ratio is between about 60:40 and about 95:5, or between about 70:30 and about 90:10, or between about 75:25 and about 85:15.

5. The process of claim 4, wherein the aluminum salt-based WTR to clay material dry mass ratio is between about 75:25 and about 85:15.

6. The process of claim 4, wherein the aluminum salt-based WTR to clay material dry mass ratio is about 80:20.

7. The process of any one of claims 3 to 6, further comprising drying the at least one clay material prior to mixing the fine WTR powder with the at least one clay material.

8. The process of any one of claims 1 to 7, wherein the mixture comprises between about 20 wt% and about 40 wt% of inorganic WTR and between about 40 wt% and about 60 wt% of organic content, or between about 25 wt% and about 35 wt% of inorganic WTR and between about 45 wt% and about 55 wt% of organic content, based on a total dry mixture weight.

9. The process of any one of claims 1 to 7, wherein the mixture comprises between about 35 wt% and about 45 wt% of inorganic WTR and between about 55 wt% and about 65 wt% of organic content, based on a total dry mixture weight.

10. The process of any one of claims 1 to 7, wherein the mixture comprises between about 25 wt% and about 35 wt% of inorganic WTR and between about 45 wt% and about 55 wt% of organic content, based on the total dry mixture weight.

11. The process of any one of claims 1 to 10, wherein drying the aluminum salt-based WTR is performed at a WTR drying temperature between about 20 °C and about 150 °C, or between about 50 °C and about 130 °C, or between about 80 °C and about 120 °C, or between about 90 °C and about 115 °C.

12. The process of any one of claims 1 to 11, wherein drying the aluminum salt-based WTR is performed for a WTR drying time between about 3 h and about 24 h, or between about 6 h and about 18 h, or between about 10 h and about 14 h.

13. The process of any one of claims 1 to 12, wherein drying the aluminum salt-based WTR is performed until the aluminum salt-based WTR exhibits a WTR mass change of less than 0.5 % / h, or less than 0.3 % / h, or less than 0.2 % / h, or less than 0.1 % / h.

14. The process of any one of claims 1 to 13, wherein pulverizing the aluminum saltbased WTR achieves an average fine WTR powder particle size between about 0.02 mm and about 0.30 mm, or between about 0.05 mm and about 0.25 mm, or between about 0.10 mm and about 0.20 mm.

15. The process of any one of claims 1 to 14, wherein forming the mixture into granulated pellets is performed at a granulator spinning speed between about 20 rpm and about 70 rpm, or between about 25 rpm and about 60 rpm, or between about 30 rpm and about 50 rpm.

16. The process of any one of claims 1 to 15, wherein forming the mixture into granulated pellets comprises spraying water or a water-based solution onto the mixture to maintain a mixture moisture level between about 10 wt% and about 50 wt%, or between about 15 wt% and about 40 wt%, or between about 20 wt% and about 35 wt%.

17. The process of any one of claims 1 to 16, further comprising drying the granulated pellets prior to the sintering thereof.

18. The process of claim 17, wherein the granulated pellets are dried at a pellet drying temperature between about 20 °C and about 150 °C, or between about 50 °C and about 130 °C, or between about 80 °C and about 120 °C, or between about 90 °C and about 115 °C.

19. The process of claim 17 or 18, wherein the granulated pellets are dried for a pellet drying time between about 3 h and about 24 h, or between about 6 h and about 18 h, or between about 10 h and about 14 h.

20. The process of any one of claims 1 to 19, further comprising preheating the granulated pellets prior to the sintering thereof.

21. The process of claim 20, wherein the granulated pellets are preheated at a preheating temperature between about 250 °C and about 650 °C, or between about 350 °C and about 600 °C, or between about 400 °C and about 550 °C, or between about 450 °C and about 550 °C.

22. The process of claim 20 or 21, wherein the granulated pellets are preheated for a preheating time between about 5 min and about 30 min, or between about 10 min and about 25 min, or between about 15 min and about 25 min.

23. The process of any one of claims 1 to 22, wherein the sintering temperature is between about 750 °C and about 975 °C, or between about 800 °C and about 950 °C, or between about 850 °C and about 950 °C.

24. The process of claim 23, wherein the sintering temperature is between about 850 °C and about 950 °C.

25. The process of claim 24, wherein the sintering temperature is about 900 °C.

26. The process of any one of claims 1 to 25, wherein the sintering temperature is achieved at a heating rate between about 3 °C / min and about 30 °C / min, or between about 5 °C / min and about 25 °C / min, or between about 5 °C / min and about 15 °C / min.

27. The process of any one of claims 1 to 26, wherein the sintering time is between about 1 min and about 15 min, or between about 2 min and about 12 min, or between about 3 min and about 10 min, or between about 4 min and about 8 min.

28. The process of any one of claims 1 to 27, wherein sintering the granulated pellets is performed under a controlled atmosphere.

29. The process of any one of claims 1 to 28, wherein the ASC material exhibits a phosphate adsorption capacity of at least 55 mg P / g.

30. The process of any one of claims 1 to 29, wherein the specific surface area of the ASC material is at least 70 m2 / g.

31. The process of any one of claims 1 to 30, wherein the ASC material exhibits a compressive strength suitable for use as a lightweight aggregate in concrete production.

32. The process of any one of claims 1 to 31, wherein the ASC material is configured for use in one or more of water filtration, landscaping, and construction applications.

33. The process of claim 3, wherein:an aluminum salt-based WTR to clay material dry mass ratio is between about 75:25 and about 85:15;the mixture comprises between about 25 wt% and about 35 wt% of inorganic WTR and between about 45 wt% and about 55 wt% of organic content, based on a total dry mixture weight; andthe sintering temperature is between about 850 °C and about 950 °C.

34. The process of any one of claims 1 to 33, wherein the at least one additive comprises at least one silica-rich industrial byproduct.

35. The process of claim 34, wherein the at least one silica-rich industrial byproduct is at least one of fly ash, glass waste, and slag.

36. An aluminum salt-based ceramsite (ASC) material produced according to the process of any one of claims 1 to 35, wherein the ASC material has a phosphate adsorption capacity of at least 50 mg P / g.

37. The ASC material of claim 36, comprising residual components derived from the at least one additive.

38. A sintered aluminum salt-based ceramsite (ASC) material derived from aluminum salt-based water treatment residuals (WTR) having a porous structure having a specific surface area of at least 55 m2 / g and a phosphate adsorption capacity of at least 50 mg P / g, the ASC material comprising residual components derived from at least one additive of a feedstock used to produce the sintered ASC material.

39. The sintered ASC material of claim 38, wherein the feedstock comprises at least 50 wt% aluminum salt-based WTR, or at least 60 wt% aluminum salt-based WTR, or at least 70 wt% aluminum salt-based WTR.

40. The sintered ASC material of claim 38 or 39, wherein the at least one additive comprises at least one clay material.

41. The sintered ASC material of claim 40, wherein the feedstock has an aluminum saltbased WTR to clay material dry mass ratio between about 60:40 and about 95:5, or between about 70:30 and about 90:10, or between about 75:25 and about 85:15.

42. The sintered ASC material of any one of claims 38 to 41 , wherein the sintered ASC material is produced via a sintering step performed at a sintering temperature between about 700 °C and about 1000 °C, or between about 750 °C and about 975 °C, or between about 800 °C and about 950 °C, or between about 850 °C and about 950 °C.

43. The sintered ASC material of any one of claims 38 to 42, wherein the sintering temperature is between about 850 °C and about 950 °C.

44. The sintered ASC material of any one of claims 38 to 43, wherein the specific surface area of the ASC material is at least 70 m2 / g.

45. The sintered ASC material of any one of claims 38 to 44, having a compressive strength suitable for use as a lightweight aggregate in concrete applications.

46. The sintered ASC material of any one of claims 38 to 45, wherein the sintered ASC material is suitable for use as a high-performance adsorbent in water filtration applications.

47. The sintered ASC material of any one of claims 38 to 46, wherein the sintered ASC material is suitable for use as a moisture and nutrient retention aid in landscaping and horticulture applications.

48. The sintered ASC material of any one of claims 38 to 47, wherein the at least one additive comprises at least one silica-rich industrial byproduct.

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