PRODUCTION METHOD OF BINDING MATERIAL OBTAINED FROM MAGNESIUM SLAGS

Abstract

The invention relates to an alternative binder material production method used in the production of high-performance cements and concretes with properties similar to Portland cement clinker, from magnesium slag released during high-temperature magnesium production. In our invention, the magnesium production slag is subjected to shock cooling with water after extended sintering times to create clinker phases with high C3S and low C2S, similar to Portland cement clinker.

Description

1 TARIFF PRODUCTION OF BINDING MATERIAL OBTAINED FROM MAGNESIUM SLAGS METHOD TECHNICAL AREA 5 The invention stems from the release of magnesium during high-temperature magnesium production. from the resulting magnesium slag, a substance with properties similar to Portland cement clinker. alternative binders used in the production of high-performance cement and concrete It is related to the material production method. In our invention, magnesium production slags inside, subjected to shock cooling with water after extended sintering times 10 by leaving behind clinker with high C3S and low C2S, similar to Portland cement clinker. The formation of its phases is ensured. PREVIOUS TECHNIQUE Magnesium metal production has been increasing worldwide in recent years, reaching 15 Large quantities of magnesium slag are formed during this process. 2024 As of now, global magnesium production has reached approximately 1,000,000 tons, and this Approximately 8,500,000 tons of magnesium slag were generated during the production process. The country Based on this data, China is the world's leading magnesium producer with an annual output of 800,000 tons. It is a leading producer. Other leading producers include Russia (65,000 tons), 20 The USA (50,000 tons) and Israel (25,000 tons) are included. Also, Kazakhstan, Ukraine, Countries such as Brazil, Türkiye, South Korea, and Iran import a total of 100,000 tons of magnesium. It carries out production. These data show that magnesium production is on a global scale. This shows that it has become widespread and is an important industry. Magnesium slag, which is produced during the manufacturing of magnesium metal, 25 It is a waste product of industrial processes and accumulates in large volumes. However, this A significant portion of slag is discarded as waste without being recycled. is being stored, and this leads to both economic losses and environmental problems. This opens up the issue, especially since storage areas occupy a large space, and waste has to be handled in the long term. Risks of soil and water pollution due to release into nature and metal content of magnesium 30 This makes the disposal of slag more difficult, along with increased magnesium production. The amount of slag is also expected to increase globally, and this situation will continue in the future. This could lead to even greater environmental and economic problems in the coming years. 2 Given the current situation, magnesium slags can be effectively... Recycling and developing sustainable usage areas is of great importance. These wastes are transported back into industry through recycling processes. This will lead to a reduction in the need for raw materials, a decrease in production costs, and This will contribute to minimizing environmental impacts. Especially cement production, 5 in fields such as ceramics industry, building materials and road embankment applications Research on the use of magnesium slag as an alternative raw material. Studies show that these wastes can be recycled and contribute to the economy. In this context, Instead of storing magnesium slag as waste, it can be used as an industrial resource. Addressing this is a critical step toward achieving the sustainable development goals. will be. During magnesium metal production in Türkiye, the raw materials undergo thermochemical processing. After being subjected to reduction processes, a significant amount of magnesium is produced. magnesium slag is produced. Approximately 165 tons of magnesium slag are produced daily at the facility. these wastes are produced and sent to the factory without undergoing any recycling process. They are stored in open stockyards. When evaluated on an annual basis, in Türkiye It is estimated that over 60,000 tons of magnesium slag will be generated by 2025. Accordingly, there are plans to establish a second magnesium production facility, and this facility With the commissioning of the facility, the annual amount of magnesium slag will exceed 120,000 tons. This is expected. This situation, along with the expansion of magnesium production, will lead to increased waste management. 20 This indicates that the processes will become even more complex. In the known technique, magnesium is released during magnesium production. The slags are generally sintered at a temperature range of 1150-1300 °C for 8-12 hours. and in the open stockyard without any controlled cooling process. It is left to cool naturally. In this method, the cooling process takes place outside 25°C. It varies depending on the factors, and the lack of thermal stability This negatively affects the mineralogical structure of the slag. Especially this slow process. During the cooling process, the tricalcium silicate (alite-C₃S) phases present in the slag structure Its thermal stability is disrupted and its formation is prevented. Instead, slowly Due to cooling, a large amount of dicalcium silicate (belite-C₂S) phase is formed and 30 The amount is increasing. This situation means that magnesium production slag is used in cement production. This severely limits its potential for use, because Portland cement is the main component. The active phase, C₃S, provides properties such as high strength and rapid hydration, while C₂S The controlled phase has a lesser effect in contributing to these properties. Therefore, controlled 3 And because a rapid cooling process is not applied, magnesium slags, Portland It is unable to achieve a balanced and appropriate phase distribution as in cement clinker, This also creates a disadvantage in terms of cement performance and efficiency. BRIEF DESCRIPTION OF THE INVENTION 5 The invention stems from the release of magnesium during high-temperature production. The resulting magnesium slag is shock-cooled with water to form Portland cement clinker. It relates to a similar alternative method of producing a binder material. In our invention... Magnesium slag clinker, like cement clinker, offers high performance. The production of cements and concretes, magnesium production slag has a longer shelf life. 10 The clinker phases are similar due to the very rapid cooling after the sintering process. This is achieved by the formation of a higher level (high C3S and low C2S). Longer Sintering times and shock water cooling affect the mineralogical structure of magnesium slag. not only improves the mechanical properties, but also facilitates their integration into the cement matrix. and offers positive contributions to hydration properties. This adaptation is used in industry 15 It is capable of being integrated with the existing magnesium metal production infrastructure on this scale, It provides additional economic and environmental benefits. The advantages of our invention are listed below: - Sintering time of magnesium pellets in the temperature range of 1150-1300 °C is 8- When the hours are increased from 12 to 16 and 24 hours, the maximum magnesium metal production is 20. This ensures that the undesirable Mg metal content in the slag is also reduced. - Longer sintering times encourage the formation of higher amounts of C3S. is doing. - Simultaneously, C₃S is made more stable through shock cooling, thus converting it to C₂S. This prevents and results in higher strength clinker, thus cement 25 There is an increase in quality. - Rapid cooling optimizes grinding and sintering processes in cement production. This enables efficient production with lower energy consumption. - Magnesium slag, which is considered industrial waste, is used in cement. Its use as a substitute for clinker in production is beneficial in terms of waste management. It supports environmental sustainability and reduces dependence on natural raw materials. - Cement production costs thanks to the use of alternative raw materials in the processes. It can be reduced. Waste recycled by industry provides economic benefits. 4 - High C3S formation creates fractured and fine crystalline structures during grinding. It increases efficiency and reduces energy consumption. - It can be integrated into existing production lines in a modular way. - By enabling the production of substitute materials for cement clinker, fossil fuel consumption will be reduced and It will reduce CO₂ emissions. 5 LIST OF FIGURES Figure 1. View of the Magnesium Slag Cooling Plant. The corresponding numbers in the figures are 10. 1. Magnesium Slag 2. Reduction furnace 3. Spiral 4. Steel Bucket Belt 5. Water Spray System 15 6. Hot Gas DETAILED DESCRIPTION OF THE INVENTION The invention consists of magnesium slag (1), reduction furnace (2), screw conveyor (3), steel bucket conveyor. (4) is characterized by its water spray system (5) and hot gas (6) components. 20 In the Portland cement production process, the clinker solution phase is approximately 1260- It begins to form in the temperature range of 1310 °C. As the temperature increases, the proportion of the melt phase also increases. And this ratio, depending on the chemical composition, is approximately 20-30% by weight at 1400 °C. It reaches this level. These temperatures are the main component of Portland cement clinker. It is necessary for the formation of C3S (alite). At the beginning of sintering, along with C2S (belite), 25 A large amount of free CaO (calcium oxide) is released. The melt phase consists of free CaO and It reacts with C2S, contributing to the formation of C3S. Cement clinker, sintering. After reaching a certain temperature (1400-1450 °C), it must be rapidly cooled. This rapid cooling, It ensures that the C3S level is maintained and increased as much as possible. However, slowly. During cooling, some of the C3S in the clinker melt can transform into C2S and C3A. 30 Furthermore, at temperatures below 1250 °C, C3S loses its stability and forms free molecules with C2S. It tends to decompose into CaO. Magnesium pellets are used in reduction furnaces (2) for the production of magnesium metal. It is left to stand for a period of 8-12 hours. After this period, Taç magnesium metal production begins. While this is being done, magnesium slags (1) are also formed. The formation of magnesium production slag follows processes similar to those of cement clinker. In our invention, we produce Portland cement clinker similar to magnesium production slag. To produce an alternative binder, magnesium production slag is processed over longer periods. It undergoes sintering and subsequent rapid cooling. Magnesium 5 sintering of slag (1) at a temperature range of 1150-1300 °C for 16-24 hours During this process, the C3S phase forms in high concentrations, while the C2S phase forms in low concentrations. This extended process... The magnesium slag (1) formed after the sintering process is shock-mixed with water to the clinker. It is subjected to cooling. The main reason for this is that magnesium slag (1) clinker The stability of the C3S phase is increased by 10% through the rapid cooling process applied in the sintering zone. The goal is to protect it and prevent this phase from reverting back to C2S. Magnesium slag (1) clinker that we obtained by applying our invention. It contains 40-70% by weight of allite (tricalcium silicate, C3S). This phase dissolves rapidly in water. reacting in some way, it determines the strength and heat of hydration of the cement. It is the basic component. In rapidly cooled clinker, C3S crystals have a hexagonal structure. and cracks are observed that occur due to the effect of thermal pressing. These cracks, It increases the hydraulic activity of the clinker while also improving its grinding capability. Good In clinker formed as a result of a cooling process, the crystal ends have a sharp structure. This property positively affects the reactivity and performance of the clinker. In our invention, 20 coming out of the reduction furnace (2) in shock cooling in water. magnesium slag (1) fixed to the ground, open and heat resistant sheet metal The test was conducted by pouring water into a box-shaped metal container made of the same material. The shock cooling process was carried out inside this metal container, and the resulting... The results of the samples were analyzed (Table 1). In the water jet shock cooling process, 25 comes out of the reduction furnace (2). magnesium slag (1) directly on water spraying system (5) integrated movable It is poured onto a steel bucket conveyor belt (4). Here, the water is controlled by a spray system (5). It is somehow shock-cooled. Thus, the desired mineralogical and chemical phase is achieved. The compositions are optimized. The cooling temperatures of the material, water Temperature sensors (thermocouple) integrated into the outlet of the spray system (5) and 30 They are controlled by timers. Shock cooling performed by water spray system (5), magnesium This shock cooling reduces the temperature of the slag (1) to 35°C within 0-30 seconds. In the analyses performed as a result of the process, magnesium slag (1) clinker structure 6 Portland cement contains C3S at a similar rate to clinker phases, ranging from 40-70%. It is observed that it consists of the following components (Table 1). The clinker contains 10-20% C2S. in addition to its component, it contains minor (<2%) components such as free lime (CaO) and periclase (MgO). It is located. This result shows that the water spraying system (5) improves the mineralogical structure of cement 5 It enables the production of usable clinkers and the C₃S ratio This shows that it has been improved. This improved clinker has a higher yield in cement production. along with providing performance and durability (Table 1), industrial sustainability This also stands out as an important step in that respect. Table 1. Cooling Test Results Sample Cooling Method Final C₃S Rate (%) C₂S Rate (%) Free CaO (%) Hydration Beginning (minute) 2 Daily Strength (MPa) 28 Daily Strength (MPa) Natural cooling Open weather 0 91.47 7.10 350 6.20 28.60 Sudden shock in water 70.06 5.57 1.47 140 31.50 56.30 This Spraying Controlled shock 61.93 14.03 1.49 155 27.30 51.30 Example 1: In the magnesium production facility, in the reduction furnace (2) for 16 hours High amount of fresh magnesium slag obtained from sintered pellets (1) (daily average 165 tons) 15 after being removed from the reduction furnace (2) at a temperature of 1300 °C It was then placed directly into a metal box filled with water, which has high thermal resistance. Thermal The role of shock effect in triggering material phase transformation is to be investigated through sudden... It has been subjected to cooling. The alternative obtained as a result of the applied method. The binder product is ground in a laboratory-type ball mill to form standard cement. It has been brought to a fineness. Phase characterization of the resulting composite binder was performed using X-ray 20 The binder was analyzed using x-ray diffraction (XRD) method. According to the XRD results, the binder The structure consists of 70.06% tricalcium silicate (C₃S) and 5.57% dicalcium silicate. It has been determined that it contains (C₂S). These ratios are similar to the clinker phase in classic Portland cement. Their distributions overlap to a high degree, and even in terms of early resistance potential. It offers an advantage. The 28-day compressive strength obtained from the prepared samples is 25. 7 The value was measured as 56.30 MPa. This value is suitable for high-strength cement classes. This corresponds to a high C₃S ratio, which leads to early and ultimate strength development. supporting and revealing the hydraulic potential of thermally shock-activated slag. It places. Example 2: Magnesium slag obtained from the magnesium production process (1), high 5 It undergoes a thermochemical reduction process carried out at this temperature. In this context, magnesium slags (1) were placed in a reduction furnace (2) for 16 hours. The process is completed by waiting. After the reduction process. The resulting hot magnesium slag (1) is closed from the outlet of the reduction furnace (2). It is transported within the system via a screw conveyor (steel screw conveyor). 10 This equipment ensures homogeneous and continuous processing of material at high temperatures. It is constructed from a steel alloy structure to facilitate the drainage of magnesium slag. (1) is transferred to the moving steel bucket conveyor (4) after exiting the screw discharger. This steel bucket belt (4) is equipped with steel buckets with high temperature resistance. It supports continuous transportation operations. The transportation line has 15 sections at both the entrance and exit. and water spray system integrated into its side edges (5) magnesium This water spray system ensures the controlled cooling of the slag (1). (5) works in synchronization with the temperature sensors and automatic control unit, and sudden It preserves the phase structure by avoiding thermal shocks. With magnesium slag (1) The amount of water in contact, spray pressure and duration are process parameters 20 By optimizing, control of physical and chemical properties is ensured. Thus, With our invention, we can safely process high-temperature magnesium slag (1). The semi-finished product is obtained by cooling and having a microstructure suitable for subsequent processing. The resulting cooled magnesium slag (1) is used in cement production. They are prepared for use through processes such as phase transformation and grinding. 25

Claims

8 REQUESTS 1. Extended sintering in high-temperature magnesium production. After the periods, the magnesium slags that are released are shock cooled with water (1) by making and containing 40-70% by weight of the allite (tricalcium silicate, C3S) phase 5 It is a method of producing binder materials; its characteristic feature is: - magnesium slag at a temperature range of 1150-1300 °C for 16-24 hours sintering over a period of time, - magnesium slag (1) from the reduction furnace (2) fixed to the ground, 10 open-mouthed, heat-resistant sheet metal containers filled with water. rough casting of metal, - stages of performing the shock cooling process in this metal container It is characteristic.

2. The binding material production method mentioned in Claim 1, its characteristic is; 15 - magnesium slag at a temperature range of 1150-1300 °C for 16-24 hours sintering over a period of time, - magnesium slag (1) coming out of the reduction furnace (2) directly Moving steel bucket belt (4) with integrated water spraying system (5) spilled on it, 20 - controlled shock cooling by water spraying system (5), - by shock cooling the temperature of magnesium slag (1) within 0-30 seconds It is characterized by stages of lowering the temperature to 35°C.

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