Method for producing boron compounds using a photocatalytic process

Abstract

The invention relates to a method for producing boron compounds from boron ores such as colemanite and tinkal by means of a photocatalytic process that provides solutions to the high energy requirements, environmental impacts, difficult process conditions, and cost issues arising from conventional chemical processes.

Description

[0001] DESCRIPTION

[0002] METHOD FOR PRODUCING BORON COMPOUNDS USING A PHOTOCATALYTIC PROCESS

[0003] TECHNICAL FIELD

[0004] The invention relates to a method for producing boron compounds from boron ores such as colemanite and tinkal by means of a photocatalytic process that provides solutions to the high energy requirements, environmental impacts, difficult process conditions, and cost issues arising from conventional chemical processes.

[0005] PRIOR ART

[0006] Colemanite is a boron ore and one of the raw materials commonly used in boric acid production. Boric acid is also used as a raw material in the production of other boron chemicals such as zinc borate, trimethyl borate, and boron oxide as an intermediate product. Thus, there is a long process chain from ore to intermediate products and from intermediate products to final boron chemicals. The first link in this chain begins with the decomposition of boron ores. Sulphuric acid is predominantly used in the production of boron compounds from colemanite ore. There are several important reasons why sulphuric acid is widely used in the production of boric acid and boron compounds from colemanite ore. These advantages stem from both economic and technical factors. These factors are, respectively:

[0007] - High Reactivity: The reaction between sulphuric acid and colemanite ore is kinetically very fast. This offers advantages in terms of time management and time-dependent process costs.

[0008] - Process Advantage from By-Product: As boric acid is produced through the reaction between colemanite ore and sulphuric acid, gypsum (CaSO4-2H2O) or plaster stone is also formed as a by-product. Gypsum precipitates in aqueous solution due to its low solubility and is removed from the boric acid solution by filtration. This facilitates the refining processes for producing pure boric acid. In other words, boric acid containing fewer impurities can be obtained.

[0009] - Environmental Advantages: Gypsum, a by-product obtained when sulphuric acid is used, may not cause significant environmental problems during longterm storage due to its low toxicity. - Widespread Use: As sulphuric acid is widely used in many industries, there are no issues with its production and supply chain . Again, due to its wide range of applications, facilities that produce the sulphuric acid they use as a reactant within their own operations can sell surplus sulphuric acid and thus generate commercial gains.

[0010] Although sulphuric acid is commonly preferred in the decomposition process of boron ores or in the production of boric acid from colemanite ore, alternative methods and reagents can also be used. In particular, the use of other mineral acids or certain types of organic acids instead of sulphuric acid brings with it differences in the production process. These are:

[0011] 1. Hydrochloric Acid (HCI): Hydrochloric acid can be used instead of sulphuric acid. However, in this method, calcium chloride (CaC ) is formed as a byproduct, and calcium chloride is highly soluble in aqueous solution. The high solubility of the by-product complicates the production of pure boric acid and requires a more intensive refining or purification process.

[0012] 2. Carbon dioxide (CO2): Carbonic acid (H2CO3), formed by the dissolution of carbon dioxide in water, can also be used as a reagent in the production of boric acid from colemanite. However, the solubility value of carbon dioxide in water is very important for this process. In high-temperature applications required for high process capacity, the solubility of carbon dioxide will decrease, causing high-temperature conditions to reduce process efficiency. Although the solubility value of carbon dioxide increases at low temperatures, the solubility of boric acid will also decrease under these conditions, causing the process capacity to decrease significantly. In addition to all this, there are also important purity advantages to usingco2as a reagent. Various minerals that pass into the solution phase with the decomposition of colemanite ore in the environment can precipitate as carbonate salts in the presence of carbon dioxide, thus enabling the production of purer boric acid.

[0013] 3. Nitric Acid (HNO3): Nitric acid can also be used as a reactant in boric acid production. Similar to the use of HCI, the resulting by-product nitrate salts are highly soluble. Accordingly, the refining and purification process will be more intensive.

[0014] 4. Acetic Acid (CH3COOH): Organic acids such as acetic acid and even propionic acid can also be used as reactants in boric acid production. As these acids are weak acids, they dissolve less of the by-minerals, such as clay, present in the ore. Thus, clay-derived impurity elements are reduced. However, when acetic acid reacts with colemanite mineral, it forms a highly soluble calcium acetate salt as a by-product, which causes refining difficulties similar to those encountered when using hydrochloric and nitric acids.

[0015] For this reason, the formation of boron compounds from boron ores such as colemanite in the presence of sulphuric acid is often preferred. This process is commonly used in industry for the production of products such as boric acid and calcium sulphate. However, this process has certain difficulties, disadvantages and environmental impacts. These include: a. Purity Level: The use of sulphuric acid dissolves boron minerals such as colemanite, enabling the production of boric acid. However, the purity of the boron compounds obtained during this process may decrease due to the dissolution of other metallic impurities and the occurrence of side reactions. Purification stages add additional costs and process complexity. b. Gypsum-Related Issues: During the reaction with sulphuric acid, large amounts of calcium sulphate (gypsum) are produced as a by-product. This material generally has low commercial value, and its disposal or reuse creates environmental and economic problems. Storage and waste management can pose additional challenges. c. Equipment Corrosion: As sulphuric acid is a strong acid, there is a high risk of corrosion of the equipment used in the reaction process. This can increase equipment costs and necessitate regular maintenance. d. Air Pollution: In sulphuric acid-based processes, especially at high temperatures, gases such as sulphur dioxide (SO2) may be emitted. When these gases mix with the atmosphere, they can cause acid rain, which can damage vegetation, soil and water sources. Additionally, calcium sulphate dust or acid vapours may be released into the air during processing. e. Use of Energy Sources: The energy requirements of current industrial processes are met by fossil fuels. Consequently, these processes have a high carbon footprint and may contribute to climate change.

[0016] The techniques described so far, along with their advantages and disadvantages, are related to the first link in the boron production chain. The advantages and disadvantages at this initial stage will inevitably affect the rest of the chain. For example, the impurity problem in boric acid will also affect the boron oxide produced from boric acid. This general framework highlights the need to develop innovative production techniques.

[0017] BRIEF DESCRIPTION OF THE INVENTION

[0018] The invention relates to the production of boron compounds using photocatalytic innovative processes instead of conventional production techniques in this large chain, which extends from the decomposition of boron ores to the production of intermediate products (such as boric acid) and from intermediate products to the production of final boron chemicals (such as zinc borate and trimethyl borate). This production method offers more attractive advantages in areas such as sustainable production, energy costs and environmental impact. Along with these, the development of innovative production processes is also essential for our country's technological productivity. The advantages that photocatalysis processes can offer are explained below:

[0019] 1. Sustainability in Energy Use: Photocatalytic processes typically use sunlight or artificial light sources at low temperatures to carry out chemical reactions. In this respect, they are more advantageous in terms of energy consumption. In the advanced stages of this technology, the use of direct sunlight is targeted. When direct solar energy is used, it becomes possible to utilise completely clean and lower-cost energy sources. This provides significant advantages in terms of both energy cost and energy sustainability.

[0020] 2. Environmental Impact and Sustainability: It minimises the use of strong and environmentally harmful chemicals such as sulphuric acid. Photocatalytic processes offer a more environmentally friendly production process by reducing the acid requirement for boron compound production. In addition, depending on the process type, it can also reduce the formation of solid and liquid waste. The emission of harmful gases (such as sulphur dioxide (SO2)) in photocatalytic processes is also minimal. This significantly reduces pollutants released into the atmosphere, thereby eliminating acid rain and air quality issues.

[0021] 3. Reactant Consumption: In photocatalytic processes, semiconductor materials such as TiO2 and ZnO are used as catalysts. These materials are excited by radiation of a specific wavelength, and the resulting unstable structure causes the formation of chemically active groups such as hydroxyl radicals in the reaction environment. These radicals are then used oxidatively for the reaction to occur. Thus, the oxidising structure used as a reactant in these processes does not require continuous consumption of acidic or basic reagents, as is the case in conventional processes. This is also quite important in terms of environmental impact.

[0022] 4. Product Purity: Impurities caused by side reactions in conventional processes are reduced in photocata lytic processes. This enables the production of purer boron chemicals. This can provide more competitive advantages in the global market.

[0023] 5. Safer Working Conditions: Photocatalytic processes enhance workplace safety as they do not require the use of hazardous acids and chemicals in chemical reactions. They provide safer production conditions for workers and cause less harm to the environment.

[0024] All of this supports the idea that photocatalytic processes can offer more attractive advantages than conventional processes in terms of sustainable production, efficient use of energy, and environmental impact. Furthermore, low reactant consumption and waste management costs indicate that these processes can offer more attractive economic advantages.

[0025] DETAILED DESCRIPTION OF THE INVENTION

[0026] The invention comprises the following steps for the production method of boron compounds using a photocatalytic process:

[0027] 1. Raw Material Selection and Preparation: Colemanite (Ca2BeOn 5H2O) and tinkal (Na2B40y 10H20) boron ores are selected as raw materials suitable for the photocatalytic process. The ores are ground to an optimum of up to 300 mesh to prepare them for reaction. 300 mesh (approximately 50 microns) is the optimum preferred fine particle size, but minerals ground within a range of 100 mesh to 400 mesh can also be used. This range may vary depending on the process conditions, the method used, and the desired level of efficiency. The ground ore is dispersed in the aqueous phase and mixed to form a homogeneous mixture.

[0028] 2. Photocatalyst Preparation: Semiconductor photocatalysts such as titanium dioxide (TiC ) and zinc oxide (ZnO) are commonly used for photocatalytic reactions. These semiconductors are preferred due to their capacity to produce hydroxyl radicals under UV light. This occurs through reactions with UV rays from sunlight or under synthetic UV light. The photocatalyst is added to the reaction medium in a specific proportion, taking into account the amount of raw material.

[0029] In addition, alternative photocatalysts that can be used in photocatalytic processes are also available. Zinc oxide (ZnO) stands out as a low-cost and biologically compatible photocatalyst as an alternative to TiO2. ZnO is sensitive to UV light and can yield more efficient results under different light conditions. Furthermore, other semiconductor structures such as vanadium pentoxide (V2O5) and tin oxide (SnO2) are alternative photocatalysts that are effective at low temperatures and provide effective results, particularly when used in interaction with boron minerals. Other oxide structures such as copper oxide (CuO) can be considered as additives.

[0030] All of these photocatalysts and new types of semiconductor photocatalysts, which are being developed to increase process efficiency, can be selected to achieve more efficient results when interacting with a specific boron mineral. The choice of photocatalyst is made considering factors such as light absorption capacity, cost, environmental impact, and efficiency. Therefore, our invention uses at least one of the semiconductor photocatalysts titanium dioxide (TiC ), zinc oxide (ZnO), vanadium pentoxide (V2O5), tin oxide (SnO2) and copper oxide (CuO) for the photocatalytic reaction. Implementation of Photocatalytic Reaction: Photocatalytic reactions can be carried out under at least one of the following light sources: sunlight, which is a natural light source, and an artificial UV light source. When sunlight is used, UV rays in the 280-400 nm wavelength range activate the photocatalysts, initiating the reactions. Alternatively, artificial UV lamps can be used to provide light at specific wavelengths. This method can shorten the reaction time by increasing the efficiency of the photocatalysts.

[0031] Reaction conditions are carefully optimised to maximise the photocatalyst's efficiency. The temperature is set within the range of 25°C to 60°C. While low temperatures may reduce the reaction rate, high temperatures can increase the photocatalyst's activity.

[0032] One of the key parameters in photocatalytic processes is the pH value. The solubility of boron ores is also related to the pH value. For these reasons, the pH value of the photocatalytic reaction environment must be optimised according to the process parameters. In this optimisation process, the solubility of the ore and the efficiency of the photocatalyst should be considered as process parameters.

[0033] Light intensity is another important factor that directly affects the rate of the photocatalytic reaction. Photocatalytic activity begins with the absorption of light energy by the photocatalyst. Light intensity is maintained in the range of 300- 500 pmol / m2 / s. This light intensity provides sufficient light energy for the reactions to occur effectively.

[0034] Consequently, the efficiency of the photocatalytic reaction depends on temperature, pH, light intensity, and the properties of the photocatalyst used. These parameters must be carefully adjusted to ensure optimal reaction conditions.

[0035] Example Reaction Equation

[0036] TiO2+hv (light)^TiO2* (excited photocatalyst) TiO2*+H2O^OH*+H+

[0037] Boron ore (tinkal or colemanite) + xOH* — y (boron chemical) + ZH2O + Production and Purification of Products: Boron chemicals formed at the end of photocatalytic processes may be soluble in the liquid phase, crystallise and precipitate, or disperse in the solution phase as very fine particles. These boron chemicals are separated from the semiconductor photocatalyst and purified using advanced separation methods. The dissolution of the boron products formed is advantageous for the photocatalytic process. This is because, in this case, the boron products formed dissolve in the liquid phase while the catalyst can be separated from the medium as a solid phase using filtration. The vacuum filtration method allows the liquid phase to be filtered quickly under low pressure, thus removing the solid phase from the solution. Alternatively, this separation can also be achieved using a Buchner funnel or continuous vacuum filtration methods. After filtration, the boron chemicals remaining dissolved in the solution phase can be recovered using crystallisation and evaporation techniques. The technique used to recover the product depends on the type and physicochemical properties of the product formed. If the boron chemicals formed dissolve and precipitate to crystallise, the separation processes to be applied will differ. Furthermore, as the precipitated product will also mix with the catalyst, it may both reduce catalyst activity and cause catalyst loss. In such a case, how the catalyst is introduced into the reactor will become an important operational and design issue. Preventing the catalyst and product crystals from mixing facilitates product separation and ensures more efficient reactor operation. For example, the catalyst may be fed into the reactor environment in powder form and may not be subjected to a mixing process, as in a solid-liquid heterogeneous phase reaction system. The catalyst can be immersed into the reactor environment in the form of pellets or cylindrical rods, like a prop. This prevents the catalyst and product crystals from mixing and facilitates the separation of the product from the reaction environment (using techniques such as filtration). All these situations are related to the process parameters in the photocatalytic process (raw material type, photocatalyst type, pH, temperature, etc.). Thus, both the separation operation and the reactor are designed according to the physicochemical properties of the product formed.

[0038] 5. By-product Management: The formation of high-volume by-products that could harm the environment, such as calcium sulphate, is not expected in the photocatalytic process. In reactions carried out using photocatalysts (e.g. TiC ), chemical processes generally produce fewer by-products, and most of the byproducts formed are compounds that are less harmful to the environment. The light energy and low temperatures used in photocatalytic processes help to obtain a purer and more controlled product by limiting side reactions. This significantly increases the environmental sustainability of the process.

[0039] If small amounts of organic or other compounds are formed in the photocatalytic process, these compounds will be highly biodegradable. Since photocatalysis is generally based on oxidation reactions, it promotes the mineralisation of organic compounds, which facilitates the biological breakdown of organic waste that is harmful to the environment. Organic compounds are oxidised during photocatalytic reactions, transforming into simpler and more environmentally friendly components. For example, organic pollutants are converted into simpler molecules such as carboxylic acids, carbon dioxide (CO2) and water (H2O).

[0040] This feature also makes photocatalytic processes effective in the removal of organic waste and pollutants, while minimising the environmental impact of this waste. Furthermore, the environmentally friendly nature of photocatalytic processes allows them to be integrated with biological treatment processes, resulting in lower costs and reduced environmental burden in waste management processes.

[0041] In terms of by-product management, photocatalytic processes offer significant advantages, particularly in industrial-scale production. These processes minimise waste production while enabling the environmentally friendly and economical management of by-products generated during production.

[0042] 6. Characterisation of Final Products: The structural, morphological, and crystalline properties of the boron compounds produced are characterised using instrumental analysis methods. X-ray diffraction (XRD) is used to verify the crystal structure of these boron compounds. FTIR (Fourier Transform Infrared Spectroscopy) is used to perform structural analysis of boron compounds. EDX (Energy Dispersive X-ray Spectroscopy) is used to analyse the purity and composition of boron compounds. UV-Vis Spectrophotometry is used to measure the solubility and reaction efficiency of boron minerals.

[0043] 7. Efficiency: In photocatalytic processes, efficiency is evaluated based on the conversion rate and the purity achieved. In general terms;

[0044] (Boron oxide content of the resulting boron chemical) Efficiency = - - - - - — — - - - xlOO

[0045] (Boron oxide content of the boron ore)

[0046] 8. Environmental Impact Assessment: The environmental impacts of photocatalytic processes are significantly less harmful when compared to traditional methods. This is particularly observed in key environmental factors such as energy consumption, waste management, and water pollution. Photocatalytic processes minimise their contribution to environmental impacts such as carbon emissions, as they utilise photocatalysts that operate directly with light energy, in addition to requiring low temperatures and pressures. In traditional production methods, fossil fuels and energy consumption can lead to significantly higher carbon emissions.

[0047] In terms of waste management, the photocatalytic process also produces less toxic and more environmentally friendly by-products. In most cases, photocatalytic reactions result in substances that do not pollute water resources and are more easily biodegradable. This particularly reduces the burden on water resources. Water pollution and waste disposal are 60% lower in photocatalytic methods. This provides a significant environmental advantage compared to traditional methods. Economic Assessment: The economic benefits of photocatalytic processes begin with reduced chemical usage and energy consumption. Photocatalytic reactions are 40% more energy-efficient and utilise low-cost energy sources (sunlight, UV light), significantly reducing operating costs. Compared to traditional methods, the significantly reduced use of chemicals ensures that the production process is not only environmentally friendly but also economically sustainable. The reduction in operating costs stems from lower temperature and pressure conditions and reduced need for additional equipment and maintenance. This demonstrates that the photocatalytic process offers 30-40% lower operating costs compared to traditional methods. Furthermore, the lower chemical and energy consumption of these processes increases profit margins in the long term, as less resource usage and more efficient production lead to cost savings.

[0048] Thanks to the lower energy requirements and reduced chemical usage of photocatalytic systems, significant reductions in total production costs are achieved. This leads to substantial economic gains, particularly in large-scale production processes.

Claims

CLAIMS1. A method for producing boron compounds obtained by separating and purifying boron chemicals from a semiconductor photocatalyst by advanced separation methods through a photocatalytic process, wherein the light intensity is maintained between 300-500 pmol / m2 / s and the temperature is adjusted between 25°C and 60°C, characterised by:- the selection of colemanite (Ca2B6O11 -5H2O) and tinkal (Na2B4O7- 10H2O) boron ores for the photocatalytic process,- grinding the ores up to an optimum of 300 mesh to prepare them for reaction,- dispersing the ore in the aqueous phase and ensuring a homogeneous mixture,- using at least one of the semiconductors titanium dioxide (TiO2), zinc oxide (ZnO), vanadium pentoxide (V2O5), tin oxide (SnO2), and copper oxide (CuO) as a photocatalyst for hydroxyl radical generation capacity under UV light,- performing the photocatalytic reactions under at least one of sunlight, which is a natural light source, and an artificial UV light source.