Periclase-high-entropy spinel composite refractory material and preparation method thereof

Abstract

The invention particularly relates to a periclase-high-entropy spinel composite refractory material and a preparation method thereof. According to the technical scheme, the preparation method comprises the following steps: mixing multi-component metal chlorate, a complexing agent and water according to the molar ratio of the complexing agent to the multi-component metal chlorate of (1-3): 1, and stirring to obtain multi-component metal oxide sol with the concentration of 10-40wt%; taking 60-90wt% of periclase and 10-40wt% of multi-component metal oxide sol as raw materials, mixing the multi-component metal oxide sol with the periclase, drying, adding a binding agent accounting for 1-8wt% of the raw materials, mixing, and carrying out compression molding; and then heating to 1400-1600 DEG C in an air atmosphere at a rate of 5-10 DEG C / min, and cooling to room temperature along with the furnace to prepare the periclase-high-entropy spinel composite refractory material. The preparation method has the characteristics of easiness in process control, low cost and high production efficiency, and the prepared periclase-high-entropy spinel composite refractory material is good in thermal shock resistance, good in hydration resistance and excellent in mechanical property.

Description

Technical Field

[0001] This invention belongs to the technical field of periclase composite refractory materials. Specifically, it relates to a periclase-high entropy spinel composite refractory material and its preparation method. Background Technology

[0002] Pernicoptere (MgO), with a melting point as high as 2800℃, possesses excellent high-temperature performance, chemical stability, and strong resistance to alkaline slag erosion, making it a core component of magnesia refractories. Due to the good high-temperature resistance and slag erosion resistance of magnesia refractories, they have been widely used in iron and steel metallurgy, cement rotary kilns, glass, and lime kilns. However, the average coefficient of thermal expansion of periclase from room temperature to 1000℃ is approximately 13.5 × 10⁻⁶. -6 At temperatures below a certain temperature (°C), the high thermal expansion coefficient leads to stress concentration and poor thermal shock resistance. At room temperature, magnesia readily reacts with water, undergoing a hydration process to form magnesium hydroxide [Mg(OH)₂], causing volume expansion and structural damage, severely impacting the performance and service life of the refractory material. Therefore, those skilled in the art have conducted research on improving the thermal shock resistance, hydration resistance, and mechanical properties of magnesia refractories. The technologies described in "A Magnesium-Manganese Spinel Refractory Material and Its Preparation Method and Application" (CN 118754611 A), "A Magnesium-Iron Spinel Brick for Cement Kilns and Its Preparation Method" (CN 118754614 A), and "A Low-Alumina Magnesia Composite Unburned Brick and Its Preparation Method" (CN 111302769 A) all involve adding or in-situ generating magnesium-aluminum spinel, manganese-aluminum spinel, zinc-aluminum spinel, or iron-aluminum spinel to magnesia sand (periacriticite) to prepare magnesia refractory materials. However, spinel raw materials have low activity and are not easy to sinter. Directly adding spinel makes it difficult to achieve dense sintering of magnesia refractory materials, resulting in poor mechanical properties of the finished products. Moreover, the in-situ generation of spinel causes a volume expansion of about 8%, which can easily lead to material structural damage.

[0003] The technology described in "A non-fired magnesia-alumina spinel brick for impregnated tubes in an RH refining furnace and its preparation method" (CN 118812241 B) involves the addition of magnesia-alumina spinel, silicon carbide, titanium dioxide powder, and boron oxide powder to prepare magnesia refractory materials. However, the non-fired process inherently presents challenges in raw material processing, mixing and molding, and binder compatibility. Furthermore, it is prone to forming a borosilicate glass phase under high-temperature conditions, which reduces the material's high-temperature mechanical properties and thermal shock resistance.

[0004] The technology described in "A superhydrophobic alkaline refractory material that is difficult to water-convert and its preparation method" (CN 116730728 B) utilizes an organic coupling agent, inorganic micro / nano powders, and an organic solvent to obtain an organic... An inorganic composite modification solution is uniformly coated onto an alkaline refractory material, forming a superhydrophobic organic layer on its surface. Inorganic composite protective layers are available, but the modified solution is expensive, and the use of organic coupling agents and solvents is environmentally unfriendly. Small amounts of inorganic micro-nano powders are difficult to form a continuous protective layer with magnesium oxide and / or calcium oxide, which is not conducive to improving the material's high-temperature hydration resistance. Furthermore, due to the meticulous coating operation and high rework rate, the production efficiency is low. Summary of the Invention

[0005] This invention aims to overcome the shortcomings of existing materials and provides a method for preparing periclase-high entropy spinel composite refractory materials that is easy to control, low in cost, and high in production efficiency. The periclase-high entropy spinel composite refractory materials prepared by this method have good thermal shock resistance, good hydration resistance, and excellent mechanical properties.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: The complexing agent and the polymetallic chloride were mixed with water at a molar ratio of 1 to 3 to 1, and stirred to obtain a polymetallic oxide sol with a concentration of 10 to 40 wt%. Then, using 60 to 90 wt% periclase and 10 to 40 wt% of the polymetallic oxide sol as raw materials, the polymetallic oxide sol was mixed with the periclase, dried, and a binder of 1 to 8 wt% of the raw materials was added. The mixture was then pressed into shape. The temperature was then raised to 1400 to 1600 °C at a rate of 5 to 10 °C / min in an air atmosphere, and then cooled to room temperature in the furnace to obtain a periclase-high entropy spinel composite refractory material.

[0007] The multi-component metal chloride salt is composed of five or more metal chloride salts; the metal chloride salt is one of magnesium chloride, nickel chloride, manganese chloride, ferrous chloride, cobalt chloride, copper chloride, zinc chloride, and aluminum chloride; the molar ratio of the other metal chloride salts in the multi-component metal chloride salt is equal, except for aluminum chloride; the molar ratio of aluminum chloride to any one of the other metal chloride salts is 9~14:1; the purity of the multi-component metal chloride salt is ≥98wt%.

[0008] The complexing agent is citric acid or propylene oxide.

[0009] The stirring time is 0.5 to 2 hours; the stirring speed is 500 to 1000 rpm.

[0010] The periclase has an MgO content ≥ 98 wt% and a particle size ≤ 5 mm.

[0011] The binder is one of pulp waste liquor, polyvinyl alcohol, and phenolic resin.

[0012] The pressure during the pressing process is 100~300MPa.

[0013] The drying temperature is 80~110℃, and the drying time is 6~12h.

[0014] The heat preservation time is 2-6 hours.

[0015] By adopting the above technical solution, the present invention has the following advantages compared with the prior art: 1. This invention first mixes and stirs a multi-component metal chloride salt, a complexing agent, and water to obtain a multi-component metal oxide sol with a concentration of 10-40 wt%. This sol is then mixed with periclase particles, dried, and a binder of 1-8 wt% of the raw materials is added. The mixture is then pressed into shape and fired in an air atmosphere. The entire process is short, easy to control, low in cost, and highly efficient.

[0016] 2. This invention employs a multi-component metal oxide sol (M(OH)). x When mixed with periclase particles, the metal elements in the multi-component metal oxide sol achieve uniform mixing at the molecular level, forming a uniform coating layer on the periclase particle surface. The metal hydroxyl groups in the multi-component metal oxide sol bond with the broken Mg–O bonds on the periclase surface, forming a stable Mg–O–M bridging structure, significantly enhancing the interfacial bonding force between the two phases. During firing, high-entropy aluminate spinel is generated in situ on the periclase surface, forming a core-shell structure of "perclase as the core and high-entropy spinel as the shell." This not only improves the bonding strength but also effectively prevents liquid water / water vapor from contacting the periclase, greatly enhancing the hydration resistance of the periclase-high-entropy spinel composite refractory material.

[0017] 3. This invention employs a unique "brick-mud" composite structure in its material design, where magnesia (pericarpeggio) particles act as the "brick phase" and are uniformly encapsulated by a high-entropy spinel phase as the "mud phase." In this structural design, the high-entropy spinel phase effectively buffers the mechanical and thermal stresses experienced by the pericarpeggio-high-entropy spinel composite refractory during service, disperses fracture energy, and significantly inhibits crack initiation, propagation, and penetration. This effectively prevents sudden fracture of the pericarpeggio-high-entropy spinel composite refractory and significantly improves its compressive strength, flexural strength, and fracture toughness.

[0018] 4. This invention utilizes the entropy stabilization effect and retarded diffusion effect of high-entropy spinel to significantly enhance the high-temperature stability and toughness of periclase-high-entropy spinel composite refractories. Simultaneously, the thermal expansion mismatch between high-entropy spinel and periclase leads to the formation of dispersed microcracks within the periclase-high-entropy spinel composite refractories, effectively preventing the propagation of main cracks, reducing the brittleness of the periclase-high-entropy spinel composite refractories, and improving residual strength and thermal shock resistance. Furthermore, the composition of high-entropy spinel is highly tunable; key properties such as the coefficient of thermal expansion and thermal conductivity can be flexibly controlled by adjusting the proportions of multi-component metal chlorides to meet the needs of different application scenarios.

[0019] 5. This invention utilizes a multi-component metal oxide sol to react in situ with periclase to generate high-entropy aluminate spinel. This results in a uniform distribution of the high-entropy aluminate spinel phase, which exhibits excellent high-temperature stability and good hydration resistance, comprehensively improving the service performance of periclase-high-entropy spinel composite refractory materials. The in-situ synthesis method enhances the interfacial bonding between the two phases, leading to a more uniform stress distribution in the periclase-high-entropy spinel composite refractory material during heating and stress, thereby synergistically improving strength, toughness, and thermal shock resistance.

[0020] The periclase-high-entropy spinel composite refractory material prepared by this invention was tested and found to have a bulk density of 2.8~3.2 g / cm³. 3 The apparent porosity is 10-20%; the compressive strength at room temperature is 60-150 MPa; the softening temperature under 0.2 MPa load is 1500-1700℃; the hydration weight gain rate after 10 hours of storage at 50℃ and 90% relative humidity is 1-5%; and the thermal shock resistance of the composite refractory material is 15-40 cycles under 1100℃ and water cooling conditions.

[0021] Therefore, the present invention has the characteristics of easy process control, low cost and high production efficiency. The prepared periclase-high entropy spinel composite refractory material has good thermal shock resistance, good hydration resistance and excellent mechanical properties. Attached Figure Description

[0022] Figure 1 The image shows the XRD pattern of a periclase-high-entropy spinel composite refractory material prepared according to the present invention. Figure 2 for Figure 1 The image shown is a SEM image of the periclase-high-entropy spinel composite refractory. Figure 3 for Figure 1 The figure shows the Mg element distribution of the periclase-high-entropy spinel composite refractory. Figure 4 for Figure 1 The diagram shows the O element distribution of the periclase-high-entropy spinel composite refractory. Figure 5 for Figure 1 The diagram shows the Mn element distribution of the periclase-high-entropy spinel composite refractory. Figure 6 for Figure 1 The figure shows the Co element distribution of the magnesite-high-entropy spinel composite refractory. Figure 7 for Figure 1 The diagram shows the Cu element distribution of the periclase-high-entropy spinel composite refractory. Figure 8 for Figure 1 The diagram shows the Zn element distribution of the magnesite-high-entropy spinel composite refractory. Figure 9 for Figure 1 The diagram shows the Al element distribution of the magnesite-high-entropy spinel composite refractory. Figure 10 The image shows the XRD pattern of another periclase-high entropy spinel composite refractory material prepared according to the present invention. Detailed Implementation

[0023] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, but this is not intended to limit the scope of protection thereof.

[0024] A periclase-high entropy spinel composite refractory material and its preparation method. The preparation method described in this specific embodiment is as follows: The preparation method is as follows: the multi-component metal chloride, the complexing agent, and water are mixed and stirred at a molar ratio of complexing agent to multi-component metal chloride of 1-3:1 to obtain a multi-component metal oxide sol with a concentration of 10-40 wt%; then, using 60-90 wt% periclase and 10-40 wt% of the multi-component metal oxide sol as raw materials, the multi-component metal oxide sol is mixed with the periclase, dried, and a binder of 1-8 wt% of the raw materials is added, mixed, and pressed into shape; then, the temperature is raised to 1400-1600℃ in air at a rate of 5-10℃ / min, and cooled to room temperature in the furnace to obtain a periclase-high-entropy spinel composite refractory material.

[0025] The multi-component metal chloride salt is composed of five or more metal chloride salts; the metal chloride salt is one of magnesium chloride, nickel chloride, manganese chloride, ferrous chloride, cobalt chloride, copper chloride, zinc chloride, and aluminum chloride; the molar ratio of the other metal chloride salts in the multi-component metal chloride salt is equal, except for aluminum chloride; the molar ratio of aluminum chloride to any one of the other metal chloride salts is 9~14:1; the purity of the multi-component metal chloride salt is ≥98wt%.

[0026] The complexing agent is citric acid or propylene oxide.

[0027] The stirring time is 0.5 to 2 hours; the stirring speed is 500 to 1000 rpm.

[0028] The periclase has an MgO content of ≥98wt%.

[0029] The binder is one of pulp waste liquor, polyvinyl alcohol, and phenolic resin.

[0030] The pressure during the pressing process is 100~300MPa.

[0031] The drying temperature is 80~110℃, and the drying time is 6~12h.

[0032] The heat preservation time is 2-6 hours.

[0033] In this specific implementation: The grain size of periclase is ≤5 mm.

[0034] The details will not be repeated in the examples.

[0035] Example 1 A periclase-high-entropy spinel composite refractory material and its preparation method. The preparation method described in this embodiment is as follows: The complexing agent and the polymetallic chloride were mixed with water at a molar ratio of 1:1 to obtain a polymetallic oxide sol with a concentration of 10 wt%. Then, using 60 wt% periclase and 40 wt% of the polymetallic oxide sol as raw materials, the polymetallic oxide sol was mixed with the periclase, dried, and a binder accounting for 1 wt% of the raw materials was added. The mixture was then pressed into shape. Finally, the mixture was heated to 1400°C in air at a rate of 5°C / min and cooled to room temperature in the furnace to obtain a periclase-high-entropy spinel composite refractory material.

[0036] The multi-component metal chloride is composed of five or more metal chlorides; the metal chlorides are magnesium chloride, nickel chloride, manganese chloride, ferrous chloride, and aluminum chloride; the molar ratios of the other metal chlorides (excluding aluminum chloride) in the multi-component metal chloride are equal; the molar ratio of aluminum chloride to any one of the other metal chlorides is 9:1; the purity of the multi-component metal chloride is 98 wt%.

[0037] The complexing agent is propylene oxide.

[0038] The stirring time is 0.5 hours; the stirring speed is 500 rpm.

[0039] The periclase has an MgO content of 98 wt%.

[0040] The binder is pulp waste liquid.

[0041] The pressure during the pressing process is 100 MPa.

[0042] The drying temperature is 80℃ and the drying time is 6 hours.

[0043] The heat preservation time is 2 hours.

[0044] The periclase-high-entropy spinel composite refractory material prepared in this embodiment was tested and found to have a bulk density of 2.86 g / cm³. 3 The apparent porosity is 18.5%; the compressive strength at room temperature is 95 MPa; the softening temperature under 0.2 MPa load is 1580℃; the hydration weight gain rate after 10 hours of storage at 50℃ and 90% relative humidity is 1%; and the thermal shock resistance of the composite refractory material is 35 cycles under 1100℃ and water cooling conditions.

[0045] Example 2 A periclase-high-entropy spinel composite refractory material and its preparation method. The preparation method described in this embodiment is as follows: The complexing agent and the polymetallic chloride were mixed with water at a molar ratio of 1.2:1, and stirred to obtain a polymetallic oxide sol with a concentration of 15 wt%. Then, using 65 wt% periclase and 35 wt% of the polymetallic oxide sol as raw materials, the polymetallic oxide sol was mixed with the periclase, dried, and a binder accounting for 3 wt% of the raw materials was added. The mixture was then pressed into shape. Finally, the temperature was raised to 1450°C in air at a rate of 6°C / min, and then cooled to room temperature in the furnace to obtain a periclase-high-entropy spinel composite refractory material.

[0046] The multi-component metal chloride salt is composed of five or more metal chloride salts; the metal chloride salts are magnesium chloride, cobalt chloride, copper chloride, zinc chloride, and aluminum chloride; the molar ratios of the other metal chloride salts (excluding aluminum chloride) in the multi-component metal chloride salt are equal; the molar ratio of aluminum chloride to any one of the other metal chloride salts is 9:1; the purity of the multi-component metal chloride salt is 98.1 wt%.

[0047] The complexing agent is citric acid.

[0048] The stirring time is 0.8 hours; the stirring speed is 600 rpm.

[0049] The periclase has an MgO content of 98.1 wt%.

[0050] The binder is polyvinyl alcohol.

[0051] The pressure during the pressing process is 150 MPa.

[0052] The drying temperature is 85℃ and the drying time is 8 hours.

[0053] The heat preservation time is 3 hours.

[0054] The periclase-high-entropy spinel composite refractory material prepared in this embodiment was tested and found to have a bulk density of 3.05 g / cm³. 3 The apparent porosity is 13.9%; the compressive strength at room temperature is 145 MPa; the softening temperature under 0.2 MPa load is 1650℃; the hydration weight gain rate after 10 hours of storage at 50℃ and 90% relative humidity is 1.8%; and the thermal shock resistance of the composite refractory material is 40 cycles under 1100℃ and water cooling conditions.

[0055] Example 3 A periclase-high-entropy spinel composite refractory material and its preparation method. The preparation method described in this embodiment is as follows: The complexing agent and the polymetallic chloride were mixed with water at a molar ratio of 1.8:1 to obtain a polymetallic oxide sol with a concentration of 20 wt%. Then, using 70 wt% periclase and 30 wt% of the polymetallic oxide sol as raw materials, the polymetallic oxide sol was mixed with the periclase, dried, and a binder accounting for 5 wt% of the raw materials was added. The mixture was then pressed into shape. Finally, the temperature was raised to 1500°C in air at a rate of 7°C / min, and then cooled to room temperature in the furnace to obtain a periclase-high-entropy spinel composite refractory material.

[0056] The multi-component metal chloride salt is composed of five or more metal chloride salts; the metal chloride salts are magnesium chloride, manganese chloride, cobalt chloride, copper chloride, zinc chloride, and aluminum chloride; the molar ratios of the other metal chloride salts (excluding aluminum chloride) in the multi-component metal chloride salt are equal; the molar ratio of aluminum chloride to any one of the other metal chloride salts is 10:1; the purity of the multi-component metal chloride salt is 98.2 wt%.

[0057] The complexing agent is propylene oxide.

[0058] The stirring time is 1 hour; the stirring speed is 700 rpm.

[0059] The periclase has an MgO content of 98.2 wt%.

[0060] The binder is phenolic resin.

[0061] The pressure during the pressing process is 180 MPa.

[0062] The drying temperature is 90℃ and the drying time is 9 hours.

[0063] The heat preservation time is 4 hours.

[0064] The periclase-high-entropy spinel composite refractory material prepared in this embodiment was tested and found to have a bulk density of 3.16 g / cm³. 3 The apparent porosity is 11.7%; the room temperature compressive strength is 75 MPa; the softening temperature under 0.2 MPa load is 1590℃; the hydration weight gain rate after 10 hours of storage at 50℃ and 90% relative humidity is 2.5%; and the thermal shock resistance of the composite refractory material is 28 cycles under 1100℃ and water cooling conditions.

[0065] Example 4 A periclase-high-entropy spinel composite refractory material and its preparation method. The preparation method described in this embodiment is as follows: The complexing agent and the polymetallic chloride were mixed with water at a molar ratio of 2.2:1, and stirred to obtain a polymetallic oxide sol with a concentration of 30 wt%. Then, using 80 wt% periclase and 20 wt% of the polymetallic oxide sol as raw materials, the polymetallic oxide sol was mixed with the periclase, dried, and a binder accounting for 6 wt% of the raw materials was added. The mixture was then pressed into shape. Finally, the temperature was raised to 1520°C in air at a rate of 8°C / min, and then cooled to room temperature in the furnace to obtain a periclase-high-entropy spinel composite refractory material.

[0066] The multi-component metal chloride salt is composed of five or more metal chloride salts; the metal chloride salts are magnesium chloride, nickel chloride, ferrous chloride, cobalt chloride, copper chloride, and aluminum chloride; the molar ratios of the other metal chloride salts (excluding aluminum chloride) in the multi-component metal chloride salt are equal; the molar ratio of aluminum chloride to any one of the other metal chloride salts is 10:1; the purity of the multi-component metal chloride salt is 98.3 wt%.

[0067] The complexing agent is citric acid.

[0068] The stirring time is 1.5 hours; the stirring speed is 800 rpm.

[0069] The periclase has an MgO content of 98.3 wt%.

[0070] The binder is pulp waste liquid.

[0071] The pressure during the pressing process is 200 MPa.

[0072] The drying temperature is 100℃ and the drying time is 10 hours.

[0073] The heat preservation time is 4.5 hours.

[0074] The periclase-high-entropy spinel composite refractory material prepared in this embodiment was tested and found to have a bulk density of 3.20 g / cm³. 3 The apparent porosity is 10%; the compressive strength at room temperature is 80 MPa; the softening temperature under a 0.2 MPa load is 1620℃; the hydration weight gain rate after 10 hours of storage at 50℃ and 90% relative humidity is 3%; and the thermal shock resistance of the composite refractory material is 32 cycles under 1100℃ and water-cooling conditions.

[0075] Example 5 A periclase-high-entropy spinel composite refractory material and its preparation method. The preparation method described in this embodiment is as follows: The complexing agent and the polymetallic chloride were mixed with water at a molar ratio of 2.8:1, and stirred to obtain a polymetallic oxide sol with a concentration of 35 wt%. Then, using 85 wt% periclase and 15 wt% of the polymetallic oxide sol as raw materials, the polymetallic oxide sol was mixed with the periclase, dried, and a binder accounting for 7 wt% of the raw materials was added. The mixture was then pressed into shape. Finally, the temperature was raised to 1550°C in air at a rate of 9°C / min, and then cooled to room temperature in the furnace to obtain a periclase-high-entropy spinel composite refractory material.

[0076] The multi-component metal chloride salt is composed of five or more metal chloride salts; the metal chloride salts are magnesium chloride, nickel chloride, manganese chloride, ferrous chloride, cobalt chloride, zinc chloride, and aluminum chloride; the molar ratios of the other metal chloride salts (excluding aluminum chloride) in the multi-component metal chloride salt are equal; the molar ratio of aluminum chloride to any one of the other metal chloride salts is 12:1; the purity of the multi-component metal chloride salt is 98.4 wt%.

[0077] The complexing agent is propylene oxide.

[0078] The stirring time was 1.7 hours; the stirring speed was 900 rpm.

[0079] The periclase has an MgO content of 98.4 wt%.

[0080] The binder is polyvinyl alcohol.

[0081] The pressure during the pressing process is 250 MPa.

[0082] The drying temperature was 105℃, and the drying time was 11 hours.

[0083] The heat preservation time is 5 hours.

[0084] The periclase-high-entropy spinel composite refractory material prepared in this embodiment was tested and found to have a bulk density of 2.8 g / cm³. 3 The apparent porosity is 20%; the compressive strength at room temperature is 90 MPa; the softening temperature under 0.2 MPa load is 1560℃; the hydration weight gain rate after 10 hours of storage at 50℃ and 90% relative humidity is 1.5%; and the thermal shock resistance of the composite refractory material is 36 cycles under 1100℃ and water cooling conditions.

[0085] Example 6 A periclase-high-entropy spinel composite refractory material and its preparation method. The preparation method described in this embodiment is as follows: The complexing agent and the polymetallic chloride were mixed with water at a molar ratio of 3:1 to obtain a polymetallic oxide sol with a concentration of 40 wt%. Then, using 90 wt% periclase and 10 wt% of the polymetallic oxide sol as raw materials, the polymetallic oxide sol was mixed with the periclase, dried, and a binder accounting for 8 wt% of the raw materials was added. The mixture was then pressed into shape. Finally, the temperature was raised to 1600°C in air at a rate of 10°C / min, and then cooled to room temperature in the furnace to obtain a periclase-high-entropy spinel composite refractory material.

[0086] The multi-component metal chloride salt is composed of five or more metal chloride salts; the metal chloride salts are magnesium chloride, manganese chloride, ferrous chloride, cobalt chloride, copper chloride, zinc chloride, and aluminum chloride; the molar ratios of the other metal chloride salts (excluding aluminum chloride) in the multi-component metal chloride salt are equal; the molar ratio of aluminum chloride to any one of the other metal chloride salts is 12:1; the purity of the multi-component metal chloride salt is 98.5 wt%.

[0087] The complexing agent is citric acid.

[0088] The stirring time is 2 hours; the stirring speed is 1000 rpm.

[0089] The periclase has an MgO content of 98.5 wt%.

[0090] The binder is phenolic resin.

[0091] The pressure during the pressing process is 300 MPa.

[0092] The drying temperature is 110℃ and the drying time is 12 hours.

[0093] The heat preservation time is 6 hours.

[0094] The periclase-high-entropy spinel composite refractory material prepared in this embodiment was tested and found to have a bulk density of 3.0 g / cm³. 3The apparent porosity is 16.4%; the room temperature compressive strength is 150 MPa; the softening temperature under 0.2 MPa load is 1630℃; the hydration weight gain rate after 10 hours of storage at 50℃ and 90% relative humidity is 1.2%; and the thermal shock resistance of the composite refractory material is 39 cycles under 1100℃ and water cooling conditions.

[0095] Example 7 A periclase-high-entropy spinel composite refractory material and its preparation method are disclosed. The preparation method described in this embodiment is the same as in Example 1, except as follows: The multi-component metal chloride salt is composed of five or more metal chloride salts; the metal chloride salts are nickel chloride, manganese chloride, cobalt chloride, copper chloride, and aluminum chloride.

[0096] The periclase-high-entropy spinel composite refractory material prepared in this embodiment was tested and found to have a bulk density of 3.06 g / cm³. 3 The apparent porosity is 15.2%; the room temperature compressive strength is 85 MPa; the softening temperature under 0.2 MPa load is 1500℃; the hydration weight gain rate after 10 hours of storage at 50℃ and 90% relative humidity is 2.8%; and the thermal shock resistance of the composite refractory material is 25 cycles under 1100℃ and water cooling conditions.

[0097] Example 8 A periclase-high-entropy spinel composite refractory material and its preparation method are disclosed. The preparation method described in this embodiment is the same as in Example 2, except as described below. The multi-component metal chloride salt is composed of five or more metal chloride salts; the metal chloride salts are magnesium chloride, nickel chloride, ferrous chloride, zinc chloride and aluminum chloride.

[0098] The periclase-high-entropy spinel composite refractory material prepared in this embodiment was tested and found to have a bulk density of 3.13 g / cm³. 3 The apparent porosity is 12%; the compressive strength at room temperature is 100 MPa; the softening temperature under 0.2 MPa load is 1570℃; the hydration weight gain rate after 10 hours of storage at 50℃ and 90% relative humidity is 2.2%; and the thermal shock resistance of the composite refractory material is 34 cycles under 1100℃ and water cooling conditions.

[0099] Example 9 A periclase-high-entropy spinel composite refractory material and its preparation method. The preparation method described in this embodiment is the same as in Example 3, except as follows: The multi-component metal chloride salt is composed of five or more metal chloride salts; the metal chloride salts are nickel chloride, manganese chloride, ferrous chloride, cobalt chloride, zinc chloride, and aluminum chloride.

[0100] The periclase-high-entropy spinel composite refractory material prepared in this embodiment was tested and found to have a bulk density of 3.07 g / cm³. 3 The apparent porosity is 15.9%; the room temperature compressive strength is 110 MPa; the softening temperature under 0.2 MPa load is 1700℃; the hydration weight gain rate after 10 hours of storage at 50℃ and 90% relative humidity is 2%; and the thermal shock resistance of the composite refractory material is 37 cycles under 1100℃ and water cooling conditions.

[0101] Example 10 A periclase-high-entropy spinel composite refractory material and its preparation method. The preparation method described in this embodiment is the same as in Example 4, except as follows: The multi-component metal chloride salt is composed of five or more metal chloride salts; the metal chloride salts are magnesium chloride, manganese chloride, ferrous chloride, copper chloride, zinc chloride and aluminum chloride; the molar ratios of the other metal chloride salts except aluminum chloride are equal; the molar ratio of aluminum chloride to any one of the other metal chloride salts is 11:1.

[0102] The periclase-high-entropy spinel composite refractory material prepared in this embodiment was tested and found to have a bulk density of 3.05 g / cm³. 3 The apparent porosity is 16.3%; the room temperature compressive strength is 120 MPa; the softening temperature under 0.2 MPa load is 1680℃; the hydration weight gain rate after 10 hours of storage at 50℃ and 90% relative humidity is 5%; and the thermal shock resistance of the composite refractory material is 30 cycles under 1100℃ and water cooling conditions.

[0103] Example 11 A periclase-high-entropy spinel composite refractory material and its preparation method. The preparation method described in this embodiment is the same as in Example 5, except as described below: The multi-component metal chloride salt is composed of five or more metal chloride salts; the metal chloride salts are magnesium chloride, nickel chloride, manganese chloride, cobalt chloride, copper chloride, zinc chloride, and aluminum chloride.

[0104] The periclase-high-entropy spinel composite refractory material prepared in this embodiment was tested and found to have a bulk density of 3.12 g / cm³. 3 The apparent porosity is 13.7%; the compressive strength at room temperature is 90 MPa; the softening temperature under 0.2 MPa load is 1600℃; the hydration weight gain rate after 10 hours of storage at 50℃ and 90% relative humidity is 3.5%; and the thermal shock resistance of the composite refractory material is 15 cycles under 1100℃ and water cooling conditions.

[0105] Example 12 A periclase-high-entropy spinel composite refractory material and its preparation method. The preparation method described in this embodiment is the same as in Example 6, except as described below: The multi-component metal chloride salt is composed of five or more metal chloride salts; the metal chloride salts are magnesium chloride, manganese chloride, ferrous chloride, cobalt chloride, copper chloride, zinc chloride, and aluminum chloride; the molar ratios of the other metal chloride salts (excluding aluminum chloride) in the multi-component metal chloride salt are equal; the molar ratio of aluminum chloride to any one of the other metal chloride salts is 13:1.

[0106] The periclase-high-entropy spinel composite refractory material prepared in this embodiment was tested and found to have a bulk density of 3.19 g / cm³. 3 The apparent porosity is 11.5%; the room temperature compressive strength is 60 MPa; the softening temperature under 0.2 MPa load is 1610℃; the hydration weight gain rate after 10 hours of storage at 50℃ and 90% relative humidity is 4.5%; and the thermal shock resistance of the composite refractory material is 22 cycles under 1100℃ and water cooling conditions.

[0107] Example 13 A periclase-high-entropy spinel composite refractory material and its preparation method. The preparation method described in this embodiment is as follows: The complexing agent and the polymetallic chloride were mixed with water at a molar ratio of 2:1 to obtain a polymetallic oxide sol with a concentration of 25 wt%. Then, using 75 wt% periclase and 25 wt% of the polymetallic oxide sol as raw materials, the polymetallic oxide sol was mixed with the periclase, dried, and a binder of 4.5 wt% of the raw materials was added. The mixture was then pressed into shape. Finally, the mixture was heated to 1500°C in air at a rate of 7.5°C / min and cooled to room temperature in the furnace to obtain a periclase-high-entropy spinel composite refractory material.

[0108] The multi-component metal chloride salt is composed of five or more metal chloride salts; the metal chloride salts are magnesium chloride, nickel chloride, manganese chloride, ferrous chloride, cobalt chloride, copper chloride, zinc chloride, and aluminum chloride; the molar ratios of the other metal chloride salts (excluding aluminum chloride) in the multi-component metal chloride salt are equal; the molar ratio of aluminum chloride to any one of the other metal chloride salts is 14:1; the purity of the multi-component metal chloride salt is 98.3 wt%.

[0109] The complexing agent is propylene oxide.

[0110] The stirring time was 1.25 hours; the stirring speed was 750 rpm.

[0111] The periclase has an MgO content of 98.3 wt%.

[0112] The binder is pulp waste liquid.

[0113] The pressure during the pressing process is 200 MPa.

[0114] The drying temperature is 95℃ and the drying time is 9 hours.

[0115] The heat preservation time is 4 hours.

[0116] The periclase-high-entropy spinel composite refractory material prepared in this embodiment was tested and found to have a bulk density of 3.12 g / cm³. 3 The apparent porosity is 15.3%; the room temperature compressive strength is 92 MPa; the softening temperature under 0.2 MPa load is 1630℃; the hydration weight gain rate after 10 hours of storage at 50℃ and 90% relative humidity is 4.2%; and the thermal shock resistance of the composite refractory material is 17 cycles under 1100℃ and water cooling conditions.

[0117] This specific implementation method has the following advantages compared with the existing technical solution: 1. In this specific embodiment, a multi-component metal chloride salt, a complexing agent, and water are first mixed and stirred to obtain a multi-component metal oxide sol with a concentration of 10-40 wt%. This sol is then mixed with periclase particles, dried, and a binder accounting for 1-8 wt% of the raw materials is added. The mixture is then pressed into shape and fired in an air atmosphere. The entire process is short, easy to control, low in cost, and highly efficient.

[0118] 2. This specific embodiment uses a multi-component metal oxide sol (M(OH)). x When mixed with periclase particles, the metal elements in the multi-component metal oxide sol achieve uniform mixing at the molecular level, forming a uniform coating layer on the periclase particle surface. The metal hydroxyl groups in the multi-component metal oxide sol bond with the broken Mg–O bonds on the periclase surface, forming a stable Mg–O–M bridging structure, significantly enhancing the interfacial bonding force between the two phases. During firing, high-entropy aluminate spinel is generated in situ on the periclase surface, forming a core-shell structure of "perclase as the core and high-entropy spinel as the shell." This not only improves the bonding strength but also effectively prevents liquid water / water vapor from contacting the periclase, greatly enhancing the hydration resistance of the periclase-high-entropy spinel composite refractory material.

[0119] 3. This specific embodiment adopts a unique "brick-mud" composite structure in its material structure design, where magnesia (pericarpeggio) particles act as the "brick phase" and are uniformly encapsulated by a high-entropy spinel phase as the "mud phase." In this structural design, the high-entropy spinel phase can effectively buffer the mechanical and thermal stresses borne by the pericarpeggio-high-entropy spinel composite refractory during service, disperse fracture energy, and significantly inhibit the initiation, propagation, and penetration of cracks. This effectively avoids sudden fracture of the pericarpeggio-high-entropy spinel composite refractory and significantly improves its compressive strength, flexural strength, and fracture toughness.

[0120] 4. This specific embodiment utilizes the entropy stabilization effect and retarded diffusion effect of high-entropy spinel to significantly enhance the high-temperature stability and toughness of periclase-high-entropy spinel composite refractories. Simultaneously, the thermal expansion mismatch between high-entropy spinel and periclase creates dispersed microcracks within the periclase-high-entropy spinel composite refractories, effectively preventing the propagation of main cracks, reducing the brittleness of the periclase-high-entropy spinel composite refractories, and improving residual strength and thermal shock resistance. Furthermore, the composition of high-entropy spinel is highly tunable; key properties such as the coefficient of thermal expansion and thermal conductivity can be flexibly controlled by adjusting the proportions of multi-component metal chlorides to meet the needs of different application scenarios.

[0121] 5. This specific embodiment utilizes a multi-component metal oxide sol to react in situ with periclase to generate high-entropy aluminate spinel. This results in a uniform distribution of the high-entropy aluminate spinel phase, which exhibits excellent high-temperature stability and good hydration resistance, thus comprehensively improving the service performance of periclase-high-entropy spinel composite refractory materials. The prepared periclase-high-entropy spinel composite refractory material is shown in the attached figure. Figure 1 The image shows the XRD pattern of the periclase-high-entropy spinel composite refractory material prepared in Example 3. Figure 2 for Figure 1 The image shown is a SEM image of the periclase-high-entropy spinel composite refractory. Figure 3 for Figure 1 The figure shows the Mg element distribution of the periclase-high-entropy spinel composite refractory. Figure 4 for Figure 1 The diagram shows the O element distribution of the periclase-high-entropy spinel composite refractory. Figure 5 for Figure 1 The diagram shows the Mn element distribution of the periclase-high-entropy spinel composite refractory. Figure 6 for Figure 1 The figure shows the Co element distribution of the magnesite-high-entropy spinel composite refractory. Figure 7 for Figure 1 The diagram shows the Cu element distribution of the periclase-high-entropy spinel composite refractory. Figure 8 for Figure 1 The diagram shows the Zn element distribution of the magnesite-high-entropy spinel composite refractory. Figure 9 for Figure 1 The diagram shows the Al element distribution of the magnesite-high-entropy spinel composite refractory. Figure 10 The image shows the XRD pattern of the periclase-high entropy spinel composite refractory material prepared in Example 4.

[0122] from Figure 1 It can be seen that the phase exhibits obvious periclase amorphous phase diffraction peaks and high-entropy aluminate spinel (5M). 1 / 5 The presence of characteristic diffraction peaks of Al2O4, without the diffraction peaks of the raw materials, indicates that the synthesis reaction of high-entropy aluminate spinel is complete and the spinel phase exists stably in the prepared product. This demonstrates that the method can prepare high-purity target products, laying the foundation for the production of high-performance products.

[0123] from Figure 2 It can be seen that a high-entropy spinel layer is formed on the surface of the periclase particles, combined with... Figure 1 This layer is considered to be high-entropy aluminate spinel (5M). 1 / 5 Al2O4; from Figures 3-9 It can be seen that metallic Al elements are uniformly distributed on the surface of periclase particles. The distribution of metal elements at the A-site is not obvious in the energy spectrum due to their small atomic weight, but combined with the XRD pattern, it can be indicated that the (5M) metal elements were generated in situ. 1 / 5 )2Al2O4 forms a uniform coating on the surface of periclase particles, and the two phases are well bonded at the interface without cracks or gaps.

[0124] from Figure 10 It can be seen that the phase exhibits obvious characteristic diffraction peaks of high-entropy aluminate spinel, indicating that the high-entropy aluminate spinel phase is stably formed.

[0125] The accompanying drawings in the specification show that the in-situ synthesis method enhances the interfacial bonding between the two phases, making the stress distribution of the periclase-high-entropy spinel composite refractory more uniform during heating and stress, thereby synergistically improving strength, toughness and thermal shock resistance.

[0126] The periclase-high-entropy spinel composite refractory material prepared according to this specific embodiment has a bulk density of 2.8~3.2 g / cm³. 3The apparent porosity is 10-20%; the compressive strength at room temperature is 60-150 MPa; the softening temperature under 0.2 MPa load is 1500-1700℃; the hydration weight gain rate after 10 hours of storage at 50℃ and 90% relative humidity is 1-5%; and the thermal shock resistance of the composite refractory material is 15-40 cycles under 1100℃ and water cooling conditions.

[0127] Therefore, this specific embodiment has the characteristics of easy process control, low cost and high production efficiency. The prepared periclase-high entropy spinel composite refractory material has good thermal shock resistance, good hydration resistance and excellent mechanical properties.

Claims

1. A method for preparing a periclase-high-entropy spinel composite refractory material, characterized in that, The preparation method is as follows: the multi-component metal chloride, the complexing agent, and water are mixed and stirred at a molar ratio of complexing agent to multi-component metal chloride of 1-3:1 to obtain a multi-component metal oxide sol with a concentration of 10-40 wt%; then, using 60-90 wt% periclase and 10-40 wt% of the multi-component metal oxide sol as raw materials, the multi-component metal oxide sol is mixed with the periclase, dried, and a binder of 1-8 wt% of the raw materials is added, mixed, and pressed into shape; then, the temperature is raised to 1400-1600℃ in air at a rate of 5-10℃ / min, and cooled to room temperature in the furnace to obtain a periclase-high-entropy spinel composite refractory material.

2. The preparation method of the periclase-high-entropy spinel composite refractory material according to claim 1, characterized in that, The multi-component metal chloride salt is composed of five or more metal chloride salts; the metal chloride salt is one of magnesium chloride, nickel chloride, manganese chloride, ferrous chloride, cobalt chloride, copper chloride, zinc chloride, and aluminum chloride; the molar ratio of the other metal chloride salts in the multi-component metal chloride salt is equal, except for aluminum chloride; the molar ratio of aluminum chloride to any one of the other metal chloride salts is 9~14:1; the purity of the multi-component metal chloride salt is ≥98wt%.

3. The preparation method of the periclase-high-entropy spinel composite refractory material according to claim 1, characterized in that, The complexing agent is citric acid or propylene oxide.

4. The preparation method of the periclase-high-entropy spinel composite refractory material according to claim 1, characterized in that, The stirring time is 0.5 to 2 hours; the stirring speed is 500 to 1000 rpm.

5. The method for preparing the periclase-high-entropy spinel composite refractory material according to claim 1, characterized in that, The periclase has an MgO content ≥ 98 wt% and a particle size ≤ 5 mm.

6. The preparation method of the periclase-high-entropy spinel composite refractory material according to claim 1, characterized in that, The binder is one of pulp waste liquor, polyvinyl alcohol, and phenolic resin.

7. The preparation method of the periclase-high entropy spinel composite refractory material according to claim 1, characterized in that, The pressure during the pressing process is 100~300MPa.

8. The preparation method of the periclase-high entropy spinel composite refractory material according to claim 1, characterized in that, The drying temperature is 80~110℃, and the drying time is 6~12h.

9. The method for preparing the periclase-high-entropy spinel composite refractory material according to claim 1, characterized in that, The heat preservation time is 2-6 hours.

10. A periclase-high entropy spinel composite refractory material, characterized in that... The periclase-high entropy spinel composite refractory material is prepared by the preparation method of the periclase-high entropy spinel composite refractory material according to any one of claims 1 to 9.

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