APPLICATION OF NANO MAGNESIUM OXIDE (NANO-MgO) PARTICLE SYNTHESISED FROM MINING WASTES AS A RADIATIVE COOLING MATERIAL FOR TEXTILE PRODUCTS

Abstract

The invention relates to the synthesis of nano magnesium oxide (nano-MgO) particles from mining wastes and the application of the synthesised particles to textile products as a radiative cooling material. The invention comprises the development of cooling technologies without external energy input by means of innovative and green nanotechnological approaches using recycled mining wastes. In the invention, a material providing cooling without external energy input is developed. Said material falls within the class of radiative cooling materials.

Description

[0001] APPLICATION OF NANO MAGNESIUM OXIDE (Nano-MgO) PARTICLES SYNTHESISED FROM MINING WASTES AS A RADIATIVE COOLING MATERIAL FOR TEXTILE PRODUCTS

[0002] Technical Field of the Invention

[0003] The invention relates to the synthesis of nano magnesium oxide (nano-MgO) particles from mining wastes and the application of the synthesised particles to textile products as a radiative cooling material. The invention comprises the development of cooling technologies without external energy input by means of innovative and green nanotechnological approaches using recycled mining wastes. In the invention, a material providing cooling without external energy input is developed. Said material falls within the class of radiative cooling materials.

[0004] State of the Art

[0005] Radiative cooling is a unique system that operates without the need for external energy in order to mitigate increasingly severe hot weather conditions that threaten human health. Radiative cooling is a natural cooling process in which objects transfer heat to the atmosphere through electromagnetic radiation. This process enables objects with high emissivity, such as the human body, to cool by utilising thermal radiation present in the surrounding environment. This process, which takes place through the atmospheric window, is an energy-efficient and sustainable cooling technique. The use of radiative cooling on textile surfaces offers innovative solutions that provide energy efficiency and comfort. Radiative cooling on textile surfaces is used to keep the user cool or to reduce ambient temperature by passively dissipating heat. These applications are becoming widespread particularly in wearable technologies, outdoor textiles, and energy-efficient building materials. Radiative cooling on textile surfaces occurs by the textile emitting heat absorbed from the body or the environment in the form of infrared radiation into space or the surrounding environment. Areas of use include wearable technologies such as sportswear and daily clothing; outdoor textiles such as tents and awnings; cooling blankets used in medical applications; and militaryand industrial applications such as camping equipment and protective garments. This technology comprises nano-coatings (nano-MgO, nano-TiO2), polymer fibres, photothermal modifications, and woven designs with high reflectance-emissivity capacity. Metal oxide-based coatings are generally used to increase thermal insulation in textile products. However, these coatings are insufficient in providing homogeneous distribution during application. Existing solutions offer high cost and limited thermal performance. In addition, these materials are generally not suitable in terms of environmental sustainability.

[0006] In the state of the art, Tang et al. developed an MgO-based paint in a study conducted in 2022. In the study, a model building cooling experiment and corresponding thermodynamic modelling were carried out in order to investigate the cooling potential of the proposed paint in building applications. In addition, a life-cycle assessment was performed for the developed MgO radiative cooling paint. As a result, it was found that the MgO paint exhibited a broadband infrared emissivity of approximately 0.93 in the mid-IR region (2.5-25 pm) through phonon polariton resonances, while simultaneously providing a high solar reflectance of approximately 0.95 through particle scattering. Even on a humid and cloudy day with peak solar irradiance of 868 W / m2, a sub-ambient temperature reduction of approximately 3.5 °C and a net cooling power of approximately 61.2 W / m2were experimentally demonstrated. In this study, the MgO paint experimentally provided a sub-ambient temperature reduction of 3.5 °C [1]. However, this effect may exhibit diminished performance on humid and cloudy days. Although the environmental impact of the MgO paint was reduced by 7.92-24.75 % compared to commercial paints, no details were provided regarding recyclability or waste management. In addition, the MgO paint described in the study cannot directly provide thermal comfort for individual users, as its application is limited solely to surface coatings.

[0007] In another state of the art, Du et al. designed a passive radiative cooling textile in a 2023 study, in which the optical properties of MgO were investigated through calculations and MgO nanoparticles were integrated into porous cellulose acetate (CA) and polyester (PET) matrices. The resulting textile exhibited 94.6 % solar reflectance and 96.8 % infrared emissivity [2], A sub-ambient temperature reduction of 8 °C was achieved due to the optical properties of MgO and Mie scattering of the porous CA polymer. The polyester (PET)-based matrix used in the study has a high environmentalimpact, as PET is not biodegradable and pose adverse consequences for environmental sustainability. The dip-coating and porous structure formation processes are technically complex and may not be suitable for industrial-scale manufacturing. Furthermore, comparisons made against simulated bare-skin heaters and PET textiles are insufficient to evaluate performance under a variety of real-world conditions.

[0008] In another state of the art, Das et al. demonstrated a white, high-emissivity magnesium oxide (MgO)-polyvinylidene fluoride (PVDF) nanocomposite in a 2023 study, which exhibited an average sub-ambient temperature reduction of approximately 7 °C under direct sunlight. Optimised MgO-PVDF metamaterials with a dielectric particle size of approximately 50 nm exhibited a solar reflectance of 96.3 % due to Mie scattering and a thermal emissivity of 98.5 % within the atmospheric transmission window, attributed to anharmonic multiphonon Mg-0 bond vibrations and other stretching / bonding vibrations originating from the polymer. In said study, the MgO-PVDF nanocomposite was optimised for infrastructure-focused cooling rather than for reducing individual energy consumption or providing direct benefits to individual users. Although the coating offers water-resistant hydrophobic properties, its performance durability under long-term humid or variable weather conditions was not disclosed. Homogeneous dispersion of MgO particles within the PVDF matrix is of critical importance; otherwise, non-uniform distribution leads to the degradation of the optical and thermal properties of the material. In addition, precise control of MgO nanoparticle concentration and size represents a critical processing challenge. Although a low-cost method is claimed, maintaining low material costs during the transition from laboratory scale to commercial scale remains challenging, particularly since the synthesis and purification of MgO can be prohibitively costly. Furthermore, despite the nanocomposite's low-cost nature, it offers limited advantages in terms of sustainability or recyclability.

[0009] The limitations and inadequacies of existing solutions in the current state of the art, including the inability to ensure homogeneous heat distribution during application in smart textile composite materials with radiative cooling properties, prohibitive manufacturing costs, limited thermal performance, and lack of environmental sustainability, have necessitated an advancement in this field.Brief Description and the Aims of the Invention

[0010] The invention relates to the synthesis of nano magnesium oxide (nano-MgO) particles from mining wastes and the application of the synthesized particles to textile products as a radiative cooling material.

[0011] One aim of the invention is to increase energy efficiency in radiative materials. The invention reduces ambient temperature by effectively managing infrared radiation and provides passive radiative cooling. This increases energy efficiency.

[0012] Another aim of the invention is to provide an environmentally friendly solution for the production of radiative materials. Since the material that is the subject of the invention consists of metal oxides obtained by recycling mining wastes, it offers an ecologically friendly solution. For this reason, a low-cost and energy-efficient production process is achieved.

[0013] Another aim of the invention is to develop a material with strong mechanical properties. The material that is the subject of the invention is resistant to fracture and bending and can be used under harsh conditions such as extreme temperatures.

[0014] Another aim of the invention is to provide a practical technology specifically designed for personal thermal management and comfort. The material that is the subject of the invention can be easily used in hot regions or hot outdoor environments due to the lightweight and portable nature of the textile.

[0015] Description of the Drawings

[0016] Figure 1. Experimental setup used during the preparation of the radiative cooling textile material

[0017] Detailed Description of the Invention

[0018] The invention relates to the development of smart textile composites having radiative cooling properties based on nano magnesium oxide (nano-MgO) particles obtained from wastes. In the invention, advantages are provided in many areas such asenvironmental sustainability, wide application area, ease of production, cost advantage, and performance optimisation.

[0019] The method for obtaining nano magnesium oxide (nano-MgO) particles having specific physicochemical properties, which constitute the main component of the invention, from mining wastes is carried out by a hydrothermal method or a sol-gel method. In the synthesis of nano magnesium oxide (nano-MgO) particles by the hydrothermal method according to the invention, a solution is formed by using solutions of pure water, diluted NaOH, KOH (potassium hydroxide), LiH (lithium hydroxide), NH3(ammonia), ammonium hydroxide (NH40H), sodium carbonate (Na2CO3), sodium bicarbonate (NaHCO3), triethylamine (TEA), or ethylenediamine (EDA) as initiator chemicals together with the mining waste, and crystalline nanostructures are obtained by applying a thermal treatment to this solution at temperatures between 300 °C and 700 °C for 2-10 hours by means of an oven. The synthesis of highly crystalline nanoparticles and the ability to produce them in desired sizes and shapes are among the advantages of the hydrothermal method. The size and morphology of nano-MgO obtained by hydrothermal processes depend on the solvent composition and operating conditions.

[0020] In the method according to the invention, the synthesis of nano magnesium oxide (nano-MgO) particles from mining wastes by the hydrothermal method comprises the following process steps;

[0021] i. placing a magnesium source extracted from the mining waste into a Teflon- coated stainless-steel autoclave,

[0022] ii. adding the initiator chemical dropwise until the desired pH is obtained, iii. filling approximately 50-70 % of the reactor with water and tightly closing the lid,

[0023] iv. increasing the temperature to a selected value between 100-200 °C for a period of 10-24 hours and allowing the reactor to maintain this temperature for a predetermined duration,

[0024] v. obtaining pure magnesium hydroxide (Mg(OH)2) by washing the product obtained at the end of the reaction several times with distilled water and alcohol, and

[0025] vi. calcining the purified Mg(OH)2after drying in order to obtain nano-MgO.In the method according to the invention, the mining waste mentioned comprises magnesite (MgCO3), dolomite (CaMg(CO3)2), olivine (Mg2SiO4or (Mg,Fe)2SiO4), serpentinite (Mg3Si2O5(OH)4), brucite (Mg(OH)2), talc (Mg3Si4Oi0(OH)2), laterite (magnesium-containing nickel laterites), calcite, or dolomite mixtures.

[0026] In one embodiment of the method that is the subject of the invention, the synthesis of nano magnesium oxide (nano-MgO) particles from mining wastes by the hydrothermal method comprises the process steps of;

[0027] i. treating an aqueous magnesium carbonate (MgCO3) solution prepared at different concentrations ranging between 0.01 M and 0.5 M and extracted from mining wastes with nitric acid (HNO3),

[0028] ii. dissolving the obtained magnesium nitrate (Mg(NO3)2) precursor solution in deionised water by adding a NaOH base at concentrations ranging between 0.1 M and 0.5 M,

[0029] iii. forming white suspended particles in the resulting solution, confirming the formation of magnesium hydroxide [Mg(OH)2] nanoparticles,

[0030] iv. stirring this solution using a magnetic stirrer for approximately 10-30 minutes and then transferring the solution into a Teflon-coated stainless-steel autoclave, v. maintaining the solution at 150-200 °C for a period of 12-24 hours,

[0031] vi. subsequently washing the solution with water and ethanol until the pH reaches 7 and removing impurities, and

[0032] vii. centrifuging the washed solution for 5-15 minutes and calcining it at 400-700 °C for 4-6 hours.

[0033] In the method that is the subject of the invention, the synthesis of nano magnesium oxide (nano-MgO) particles from mining wastes by the sol-gel method comprises the process steps of;

[0034] i. dissolving magnesium nitrate Mg(NO3)2, obtained by treating an aqueous magnesium carbonate (MgCO3) solution extracted from mining wastes with nitric acid (HNO3), in deionised water,

[0035] ii. preparing a precursor solution by adding a sodium hydroxide (NaOH) solution, iii. waiting for the formation of white suspended particles in order to observe the formation of magnesium hydroxide (Mg(OH)2) nanoparticles,iv. stirring the solution using a magnetic stirrer and washing it with water and ethanol until the pH reaches 7, and

[0036] v. subsequently centrifuging and calcining the washed solution.

[0037] In one embodiment of the invention, the synthesis of nano magnesium oxide (nano-MgO) particles from mining wastes by the sol-gel method comprises the process steps of;

[0038] i. dissolving Mg(NO3)2, obtained by treating an aqueous MgCO3solution extracted from mining wastes at concentrations ranging between 0.1 M and 0.5 M with HNO3, in deionised water,

[0039] ii. preparing a precursor solution by adding a 0.1 -0.5 M NaOH solution, iii. waiting for the formation of white suspended particles in order to observe the formation of Mg(OH)2nanoparticles,

[0040] iv. stirring the solution using a magnetic stirrer for periods ranging between 10-60 minutes and washing it with water and ethanol until the pH reaches 7, and v. subsequently centrifuging the washed solution and calcining it at temperatures between 300 °C and 700 °C for 2-4 hours.

[0041] The sol-gel method is a fundamental approach aimed at the formation of metal oxides and similar inorganic materials, in which metal alkoxides are combined with suitable solvents and reactants to form homogeneous solutions. The resulting solutions can subsequently transform into colloidal suspensions (sol) and ultimately evolve into densely integrated networks (gel). Depending on the drying method, these gels can be converted into xerogels or aerogels. In optimisation of the sol-gel method, experimental series are conducted according to specific parameters with the aim of obtaining high-yield, small-sized nanoparticles. In order to determine the most suitable values, important parameters in the experimental series include pre-treatment duration (stirring time), molar volumes of metal precursor solutions, molar volumes of the solvents used, reaction temperature, calcination duration, and calcination temperature. As a result of these experimental series, nanoparticles with high yield are selected, thereby laying the groundwork for subsequent steps.

[0042] In order to apply the nano magnesium oxide (nano-MgO) particles having specific physicochemical properties, which constitute the invention and play a role in radiativecooling, to textiles, coating is performed by a dip-coating method or by an electrospinning method.

[0043] In another embodiment of the invention, the method for applying said nano magnesium oxide (nano-MgO) particles to textiles by the dip-coating comprises the process steps of;

[0044] i. cleaning and drying the textile material prior to immersion in the solution in order to remove contaminants,

[0045] ii. preparing metal precursor solutions into which the textile fabrics will be immersed,

[0046] iii. during preparation of the solution, dispersing nano magnesium oxide (nano- MgO) particles at weight percentages ranging between 0.1 % and 20 % in solvents such as water, ethanol, methanol, acetone, isopropanol (IPA), acetic acid, formamide, dimethylformamide (DMF), dimethyl sulfoxide (DMSO), acetonitrile (ACN), or dichloromethane,

[0047] iv. maintaining the solvent temperature in a controlled manner between 20 °C and 50 °C,

[0048] v. immersing the textile material comprising cellulose acetate (CA), polyethylene terephthalate (PET), or commercial cotton textile fabrics into a mixed solution containing nano magnesium oxide (nano-MgO) metal precursor solutions, vi. removing the textile material from the precursor solution after the immersion process and subjecting it to a squeezing process, and

[0049] vii. enabling homogeneous distribution of MgO within the textile and adhesion of nano magnesium oxide (nano-MgO) particles to the textile surface by means of a roller system through which the textile composite passes during the squeezing process.

[0050] Dip-coating is a process carried out by immersing the material to be coated into a solution and then withdrawing it from the solution at a controlled rate. From the MgO particles synthesised by sol-gel and hydrothermal methods and optimised in the previous steps, those exhibiting high yield are selected and solutions are prepared at specific mass ratios. Since mass percentage solution ratios, temperature, and immersion durations are effective in these experimental series, each parameter is optimised separately. MgO ratios are selected between 0.1 % and 20 % by weight;experiments are conducted at temperatures between 20 °C and 50 °C; and the final parameter, immersion duration, is varied between 30 minutes and 1 hour to prepare the textile materials. The dip-coating process comprises a roller system. As a result of all these processes, the MgO structure is thoroughly incorporated into the textile materials, and the fabric content is coated.

[0051] In one embodiment of the invention, the textile materials comprise cellulose acetate (CA), polyethylene terephthalate (PET), or commercial cotton textile fabrics.

[0052] In coating the MgO nanoparticles that are the subject of the invention onto textiles by the electrospinning method, electrostatic forces are utilised, and nanofibres are produced as electrically charged jets that are continuously stretched due to electrostatic repulsions between surface charges and subsequently solidified by evaporation of the solvent. Nanofibres can be produced from polymers, composites, ceramics, and metals directly by this method or by post-spinning processes. The electrospinning technique generally produces fabricated nanofibres having a wide diameter distribution, random orientation, and relatively low production rate. The electrospinning method is highly preferred for surface coating because it coats the surface homogeneously in the form of a thin layer.

[0053] The coating of nano magnesium oxide (nano-MgO) particles that are the subject of the invention onto textiles by the electrospinning method comprises the process steps of; i. preparing mixtures of cellulose acetate (CA) and MgO,

[0054] ii. preparing mixtures of polyethylene terephthalate (PET) and MgO,

[0055] iii. preparing mixtures of commercial cotton and MgO,

[0056] iv. placing the solution suspensions prepared in the first three process steps into the syringe of the electrospinning device, and

[0057] v. performing electrospinning at concentrations of 10 %, 15 %, and 20 % (weight / volume) for cellulose acetate (CA), polyethylene terephthalate (PET), and commercial cotton / cellulose, respectively.

[0058] In one embodiment of the invention, the parameters for coating said nano magnesium oxide (nano-MgO) particles onto textiles by the electrospinning method are flow rate, the distance between the needle tip and the collector, and the applied voltage. Operation is carried out at flow rates of 0.1 mL / h, 0.3 mL / h, and 0.5 mL / h, distances of10 cm, 15 cm, or 20 cm, and applied voltages of 15 kV, 20 kV, and 25 kV. In the method that is the subject of the invention, the viscous polymeric solution obtained is filled into the syringe, and the needles are connected to the electrode of the electrospinning machine. In order to obtain a continuous, uniform fibre and bead-free network, various process parameters such as applied voltage, polymer concentration, flow rate, humidity, and temperature are optimised.

[0059] In one embodiment of the invention, preparation of the cellulose acetate (CA) and MgO mixtures described in process step (i) of said method comprises the process steps of;

[0060] - first dissolving CA at room temperature by vigorous stirring in acetone:N,N- dimethylacetamide at ratios of 1 :1 , 1 :2, or 2:1 , and

[0061] - adding MgO at weight percentages of 0.5, 1, 1.5, and 2 and dispersing it thoroughly by sonication.

[0062] In one embodiment of the invention, preparation of the polyethylene terephthalate (PET) and MgO mixtures described in process step (ii) of said method comprises the process steps of;

[0063] - cutting PET into small pieces of 1 cm2,

[0064] - dissolving the PET at room temperature in dichloromethane (DCM):trifluoroacetic acid (TFA) solvents at ratios of 1 :1 , 1 :2, or 2:1 , and - adding ZnO, MgO, and ZnO / MgO at weight percentages of 0.5, 1 , 1.5, or 2 and dispersing them thoroughly by ultrasonication.

[0065] In one embodiment of the invention, preparation of the commercial cotton and MgO mixtures described in process step (iii) of said method comprises the process steps of;

[0066] - first dissolving cellulose at room temperature by stirring in acetic acid:acetone at ratios of 1 :1 , 1:2, or 2:1 in order to produce nanocomposites in fibre form by electrospinning, and

[0067] - subsequently dispersing and mixing solutions of ZnO, MgO, and ZnO / MgO prepared at weight percentages of 0.5, 1, 1.5, or 2 with commercial cotton / cellulose.In order to measure the cooling performance on the textile surface to which the cooling nanoparticles that are the subject of the invention are applied, an experimental setup frequently used in the literature is designed. The experimental setup is adapted for textile coating based on literature references and is used accordingly. The setup consists of an insulation foam with approximate dimensions of 30 cm x 30 cm x 15 cm, the surface of which is covered with aluminium foil. The radiative cooling textile material is placed inside, and experimental series are carried out. The upper part of the insulation foam comprises a low-density polyethylene film in order to prevent convection. Thermometers are placed at specific locations to measure internal and external temperatures.

[0068] The experimental setup to be used during preparation of the radiative cooling textile material is as shown in Figure 1. A detailed description of the components of the experimental setup is as follows: the textile material is cleaned and dried before being immersed in the solution, thereby removing contaminants. The setup comprises a container into which liquid is placed, and metal precursor solutions are introduced into this container. The container includes metal oxide solutions prepared at specific ratios and volumes. The textile material is immersed in this precursor solution and kept therein for a predetermined period. The MgO-containing precursor solution has weight percentages ranging between 1 % and 20 %, and the immersion process is carried out by varying the temperature between 20 °C and 50 °C. After the immersion process, the textile material is removed from the precursor solution and subjected to a squeezing process. By means of this setup, homogeneous formation of the MgO-textile composite is ensured and excess liquid is removed. The textile material squeezed between two rollers is homogeneously coated, and MgO nanoparticles adhere to the textile surface. After completion of these processes, the textile material is left to dry. In the invention, a textile composite material is developed that improves optical properties important for radiative cooling applications and consists of nano magnesium oxide (nano-MgO) particles prepared starting from specially synthesised organometallic compounds. The properties of this smart textile, together with its design strategy, contribute to the development of high-performance radiative cooling garments for practical purposes.In the invention, two different methods, namely a hydrothermal method and a sol-gel method, are used to synthesise metal oxide nanoparticles. During synthesis by these methods, parameters such as molar ratios of metal oxides, stirring durations, molar volume of the solvent, calcination duration, and calcination temperature affect particle size, surface area, and purity. The metal oxide nanoparticles are treated with three different polymer matrices. Subsequently, MgO nanoparticles in dispersion form are applied to textile matrices either by the electrospinning method at high speed and pressure or by a direct dip-coating method. The cooling performances of the smart composite textile materials to be obtained are compared, and the parameters of the combination operating with the highest efficiency are determined. In the invention, nano-MgO particles having a highly porous structure and low particle size are synthesised from magnesite and dolomite mining wastes by sol-gel or hydrothermal methods, and textile composites are formed by applying the produced MgO nanoparticles to textiles by electrospinning or dip-coating methods. An experimental setup is established to measure the cooling performance of the textile composites and to measure air humidity. As a result of tests carried out using this experimental setup, it has been concluded that the textile composite provides a cooling effect of 7-9 °C. The material has a wide range of applications. The raw material of the textile material can also be used in sectors such as paint, building, and construction. The ability of the material to be applied to both rigid and flexible surfaces further distinguishes the invention. The invention reduces ambient temperature by effectively managing infrared radiation and provides passive radiative cooling, thereby increasing energy efficiency. Since the material consists of metal oxides obtained by recycling mining wastes, it offers an environmentally friendly solution. For this reason, a low-cost and energyefficient production process is provided, directly addressing sustainable development goals. The material produced in the invention is durable against fracture and bending, has a long service life, and can be used under harsh conditions such as extreme temperatures. The invention is a technology specifically designed for personal thermal management and comfort, providing a much more practical benefit in daily life. In addition, due to the lightweight and portable nature of the textile, it can be easily used in hot regions or hot outdoor environments. The invention benefits from surface defects of magnesium oxides. These defects optimise resonance frequencies by affecting the vibrational modes of Mg-0 bonds, thereby increasing broadband infrared emission in the mid-IR region (2.5-25 pm). Surface defects in MgO, such as oxygen vacanciesand magnesium excess, increase electron density, leading to the formation of energy levels at the surface and higher solar reflectance. In this way, heating of the material is prevented by reflecting solar radiation. Effective passive radiative cooling is achieved through these defects. High-performance cooling is achieved together with optimised MgO ratios and additives. A more stable optical structure is provided, and performance is maintained during long-term use. The materials and methods used are green and sustainable.REFERENCES

[0069] [1] Tang, H., Li, S., Zhang, Y, Na, Y, Sun, C., Zhao, D., Liu, J., & Zhou, Z. 2022, Radiative cooling performance and life-cycle assessment of a scalable MgO paint for building applications. Journal of Cleaner Production, 380, 135035.

[0070] [2] Du, L., Zhou, Z., Li, J., Hu, B., Wang, C., Zheng, J., Liu, W, Li, R., & Chen, W. 2023, Highly efficient subambient all-day passive radiative cooling textiles with optically responsive MgO embedded in porous cellulose acetate polymer, Chemical Engineering Journal, 469, 143765.

[0071] [3] P. Das, S. Rudra, K. C. Maurya, B. Saha, 2023, Ultra-Emissive MgO-PVDF Polymer Nanocomposite Paint for Passive Daytime Radiative Cooling. Adv. Mater Technol. 8, 2301174.

Claims

CLAIMS1. A hydrothermal synthesis method of nano magnesium oxide (nano-MgO) particles from mining wastes, comprising;i. placing a magnesium source extracted from mining waste into a Teflon- coated stainless-steel autoclave,ii. adding an initiator chemical dropwise until a desired pH is obtained, iii. filling approximately 50-70 % of the reactor with water and tightly closing the lid,iv. increasing the temperature to a selected value between 100-200 °C for a period of 10-24 hours and allowing the reactor to maintain this temperature for a predetermined duration,v. obtaining pure magnesium hydroxide (Mg(OH)2) by washing the product obtained at the end of the reaction several times with distilled water and alcohol, andvi. calcining the purified Mg(OH)2after drying in order to obtain nano-MgO.

2. A method according to claim 1, wherein the mining waste is magnesite (MgCO3), dolomite (CaMg(CO3)2), olivine (Mg2SiO4or (Mg,Fe)2SiO4), serpentinite (Mg3Si2O5(OH)4), brucite (Mg(OH)2), talc (Mg3Si4Oi0(OH)2), laterite (magnesium- containing nickel laterites), calcite, or dolomite mixtures.

3. A method according to claim 1 , wherein said initiator chemical is dilute NaOH, KOH (potassium hydroxide), LiH (lithium hydroxide), NH3(ammonia), ammonium hydroxide (NH40H), sodium carbonate (Na2CO3), sodium bicarbonate (NaHCO3), triethylamine (TEA), or ethylenediamine (EDA) solutions.

4. A method according to claim 1, wherein a solution is formed by using said mining waste together with pure water, dilute NaOH (sodium hydroxide), KOH (potassium hydroxide), LiH (lithium hydroxide), NH3(ammonia), ammonium hydroxide (NH40H), sodium carbonate (Na2CO3), sodium bicarbonate (NaHCO3), triethylamine (TEA), or ethylenediamine (EDA) solutions as initiator chemicals, and a thermal treatment is applied to this solution by means of an oven at temperatures between 300 °C and 700 °C for 2-10 hours.

5. A method according to claim 1 , comprising the process steps of:i. treating an aqueous magnesium carbonate (MgCO3) solution prepared at different concentrations ranging between 0.01 M and 0.5 M and extracted from mining wastes with nitric acid (HNO3),ii. dissolving the obtained magnesium nitrate (Mg(NO3)2) precursor solution in deionised water by adding a NaOH base at concentrations ranging between 0.1 M and 0.5 M,iii. forming white suspended particles in the resulting solution, confirming the formation of magnesium hydroxide [Mg(OH)2] nanoparticles,iv. stirring this solution using a magnetic stirrer for approximately 10-30 minutes and subsequently transferring the solution into a Teflon-coated stainless- steel autoclave,v. maintaining the solution at 150-200 °C for a period of 12-24 hours, vi. subsequently washing the solution with water and ethanol until the pH reaches 7 and removing impurities, andvii. centrifuging the washed solution for 5-15 minutes and calcining it at 400- 700 °C for 4-6 hours.

6. A sol-gel synthesis method of nano magnesium oxide (nano-MgO) particles from mining wastes, comprising the process steps of:i. dissolving magnesium nitrate Mg(NO3)2, obtained by treating an aqueous magnesium carbonate (MgCO3) solution extracted from mining wastes with nitric acid (HNO3), in deionised water,ii. preparing a precursor solution by adding a sodium hydroxide (NaOH) solution,iii. waiting for the formation of white suspended particles in order to observe the formation of magnesium hydroxide (Mg(OH)2) nanoparticles,iv. stirring the solution using a magnetic stirrer and washing it with water and ethanol until the pH reaches 7, andv. subsequently centrifuging and calcining the washed solution.

7. A method according to claim 6, comprising the process steps of:i. dissolving Mg(NO3)2, obtained by treating an aqueous MgCO3solution extracted from mining wastes at concentrations ranging between 0.1 M and 0.5 M with HNO3, in deionised water,ii. preparing a precursor solution by adding a 0.1 -0.5 M NaOH solution, iii. waiting for the formation of white suspended particles in order to observe the formation of Mg(OH)2nanoparticles,iv. stirring the solution using a magnetic stirrer for periods ranging between 10- 60 minutes and washing it with water and ethanol until the pH reaches 7, andv. subsequently centrifuging the washed solution and calcining it at temperatures between 300 °C and 700 °C for 2-4 hours.

8. A nano magnesium oxide (nano-MgO) particle obtained by the method according to any one of claims 1 to 7.

9. A nano magnesium oxide (nano-MgO) particle according to claim 8, wherein the particle has a size of 20-80 nanometres.10.A textile product comprising a nano magnesium oxide (nano-MgO) particle according to claim 8 or 9.

11. A method for applying a nano magnesium oxide (nano-MgO) particle according to claim 8 or 9 onto a textile, wherein the method is a dip-coating method or an electrospinning coating method.

12. A method according to claim 11, wherein applying nano magnesium oxide (nano- MgO) particles to textiles by the dip-coating method comprises the process steps of:i. cleaning and drying the textile material before immersion in the solution in order to remove contaminants,ii. preparing metal precursor solutions into which the textile fabrics will be immersed,iii. during preparation of the solution, dispersing nano magnesium oxide (nano- MgO) particles at weight percentages ranging between 0.1 % and 20 % insolvents such as water, ethanol, methanol, acetone, isopropanol (IPA), acetic acid, formamide, dimethylformamide (DMF), dimethyl sulfoxide (DMSO), acetonitrile (ACN), or dichloromethane,iv. maintaining the solvent temperature in a controlled manner between 20 °C and 50 °C,v. immersing the textile material into a mixed solution containing nano magnesium oxide (nano-MgO) metal precursor solutions,vi. removing the textile material from the precursor solution after the immersion process and subjecting it to a squeezing process, andvii. enabling homogeneous distribution of MgO within the textile and adhesion of nano magnesium oxide (nano-MgO) particles to the textile surface by means of a roller system through which the textile composite passes during the squeezing process.13.A method according to claim 12, wherein said textile material comprises cellulose acetate (CA), polyethylene terephthalate (PET), or commercial cotton textile fabrics.

14. A method according to claim 11, wherein coating nano magnesium oxide (nano- MgO) particles onto textiles by the electrospinning method comprises the process steps of:i. preparing mixtures of cellulose acetate (CA) and MgO and preparing mixtures of polyethylene terephthalate (PET) and MgO,ii. preparing mixtures of commercial cotton and MgO,iii. placing the solution suspensions prepared in the first three process steps into the syringe of an electrospinning device, andiv. performing electrospinning at concentrations of 10 %, 15 %, and 20 % (weight / volume) for cellulose acetate (CA), polyethylene terephthalate (PET), and commercial cotton / cellulose.

15. A method according to claim 11 , wherein the electrospinning method is carried out at a flow rate of 0.1 mL / h, 0.3 mL / h, or 0.5 mL / h, at a distance of 10 cm, 15 cm, or 20 cm, and at an applied voltage of 15 kV, 20 kV, or 25 kV.

16. A method according to claim 14, wherein preparation of the cellulose acetate (CA) and MgO mixtures described in process step (i) of said method comprises the process steps of:- first dissolving CA at room temperature by vigorous stirring in acetone: N,N- dimethylacetamide at ratios of 1 :1 , 1 :2, or 2:1 , and- adding MgO at weight percentages of 0.5, 1, 1.5, and 2 and dispersing it thoroughly by sonication.

17. A method according to claim 14, wherein preparation of the polyethylene terephthalate (PET) and MgO mixtures described in process step (ii) of said method comprises the process steps of:- cutting PET into small pieces of 1 cm2,- dissolving the PET at room temperature in dichloromethane (DCM):trifluoroacetic acid (TFA) solvents at ratios of 1 :1 , 1:2, or 2:1 , and - adding zinc oxide (ZnO), magnesium oxide (MgO), and zinc oxide / magnesium oxide (ZnO / MgO) at weight percentages of 0.5, 1, 1.5, or 2 and dispersing them thoroughly by ultrasonication.

18. A method according to claim 14, wherein preparation of the commercial cotton and MgO mixtures described in process step (iii) of said method comprises the process steps of:- first dissolving cellulose at room temperature by stirring in acetic acid:acetone at ratios of 1 : 1 , 1 :2, or 2: 1 in order to produce nanocomposites in fibre form by electrospinning, and- subsequently dispersing and mixing solutions of ZnO, MgO, and ZnO / MgO prepared at weight percentages of 0.5, 1, 1.5, or 2 with commercial cotton / cellulose.

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