Spherical porcelain sand formula for high-strength electric porcelain insulator

Abstract

The invention discloses a formula of spherical porcelain sand for a high-strength electric porcelain insulator, and belongs to the technical field of preparation of porcelain sand in special insulating materials. 20%-30% of magnesium clay; wherein the pre-treated recycled pug is obtained by performing thermal activation and surface modification treatment on the pug recycled in the process of pressing the electric porcelain insulator blank pug. According to the formula, on the premise that high performance of the porcelain sand for the electric porcelain insulator is ensured, dependence on high-price raw materials and overall production cost are greatly reduced, unified optimization of cost, performance and environmental protection is achieved through the comprehensive technical scheme of waste high-valued pretreatment, specific low-price clay optimization and trace auxiliary synergistic reinforcement, and the method is suitable for industrial production. The invention provides a novel porcelain sand formula which is high in performance, low in cost and environment-friendly.

Description

Technical Field

[0001] This invention belongs to the field of ceramic sand preparation technology in special insulating materials, specifically a spherical ceramic sand formula for high-strength electrical porcelain insulators. Background Technology

[0002] Currently, in the domestic electrical porcelain industry, the connection between high-strength electrical porcelain insulators and the flange or fitting adhesive parts is generally achieved by adding cement adhesive between the two to form a strong whole. To enhance the connection strength between the adhesive parts of the porcelain parts and the adhesive, a method is generally adopted to apply sand to the adhesive parts of the blank and then fire it, so that the porcelain sand and the porcelain parts form a strong whole, thereby increasing the friction between the adhesive and the porcelain parts and improving the product strength.

[0003] The domestic electrical porcelain industry primarily relies on high-purity, high-grade natural mineral raw materials for the formulation of spherical ceramic sand used in the adhesive bonding parts of high-strength electrical porcelain insulators. Typical existing formulations usually include high-quality feldspar from Hunan (as a flux), high-quality kaolin from Shanxi (providing Al2O3 and improving plasticity), bauxite from Henan (providing additional Al2O3 to enhance strength), and talc or cordierite (used to adjust the coefficient of thermal expansion and improve thermal stability). While such formulations can produce ceramic sand products that meet basic performance requirements, long-term production practice has revealed the following significant defects and shortcomings:

[0004] 1. High raw material costs and poor economic viability. The aforementioned feldspar, high-quality kaolin, and bauxite are all carefully selected and processed ceramic-grade raw materials, with high market prices. According to industry data, the cost of the clay used to prepare this type of ceramic sand alone is as high as approximately RMB 1,200 per ton. Adding the subsequent processing costs such as crushing, grinding, granulation, and sintering, the final comprehensive cost of the ceramic sand product can climb to over RMB 12,000 per ton, significantly increasing the overall manufacturing cost of electrical porcelain insulators and weakening the product's market competitiveness.

[0005] 2. High resource consumption, inconsistent with green manufacturing principles. The existing formula relies entirely on single-use natural mineral resources, failing to effectively utilize the large amount of solid waste generated during the production of electrical porcelain. Particularly during the clay pressing (refining) process, a certain proportion of clay leaks into the slurry tank through vacuum pumps. This clay has a chemical composition similar to the main formula of the green body, but is typically treated as waste or recycled at low value. This not only wastes valuable aluminosilicate resources but also increases the company's environmental disposal pressure and overall costs.

[0006] 3. The performance improvement path is singular and overly reliant on raw material grade. Current technologies, in order to ensure the strength, thermal stability, and bonding strength with adhesives of ceramic sand, primarily focus on continuously improving the purity and grade of raw materials. However, this leads to a dilemma of "increasing costs" and "limited performance improvement." More importantly, current technologies lack targeted design for material interfaces. As an intermediate medium in adhesive bonding, the interfacial bonding strength between ceramic sand and cement adhesives is crucial to the long-term reliability of insulators. However, the surface properties of traditional raw materials and their compatibility with cement hydration products are not optimal, creating a bottleneck in improving interfacial bonding strength.

[0007] In summary, the current industry of ceramic sand for high-strength electrical porcelain insulators urgently needs an innovative technical solution that can not only maintain or even improve the comprehensive performance of ceramic sand, especially the interfacial bonding strength and long-term durability, while significantly reducing raw material costs and realizing the resource utilization of solid waste, but also improve environmental benefits. Summary of the Invention

[0008] To address the above problems, this invention provides a spherical ceramic sand formula for high-strength electrical porcelain insulators. While ensuring the high performance of the ceramic sand for electrical porcelain insulators, it significantly reduces the dependence on high-priced raw materials and the overall production cost. Through a comprehensive technical solution of "high-value pretreatment of waste materials + selection of specific inexpensive clays + synergistic enhancement with trace additives", it achieves unified optimization of cost, performance, and environmental protection, providing a new type of ceramic sand formula that is high-performance, low-cost, and environmentally friendly.

[0009] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0010] A high-strength spherical ceramic sand formula for electrical porcelain insulators is made from the following raw materials by weight percentage:

[0011] Pre-treatment recovers 70%-80% of the mud;

[0012] Magnesia clay 20%-30%;

[0013] The pretreated recycled mud material is obtained by thermal activation and surface modification of the mud material recovered during the mud pressing process of the electric porcelain insulator blank.

[0014] The above technical solution is based on "waste modification and recycling" and "structure-performance synergistic design". Firstly, the composition of the "sludge recovered during the sludge pressing process of porcelain insulator blanks" is similar to the final product, but because it is a production leak material, it typically has low activity and unstable performance. Through "thermal activation" treatment, bound water and some organic matter in the sludge can be removed, and the crystal structure of the clay minerals can be destroyed, transforming them into a more active amorphous or metastable crystalline state, significantly increasing the specific surface area and surface energy. Subsequent "surface modification treatment" (such as using a coupling agent) introduces organic functional groups onto the surface of these highly active particles, significantly improving their interfacial wettability and chemical bonding ability with subsequent inorganic binders. When combined with "magnesian clay" with specific bonding and sintering properties in the specified ratio, a microstructure can be formed during sintering, with highly active recycled material as the matrix, and magnesian clay as a sintering aid and reinforcing phase, thereby constructing porcelain sand that meets the requirements for high-strength insulators at a low cost.

[0015] In a preferred embodiment, the raw materials are expressed as follows by weight percentage: 75% pretreated recycled clay and 25% magnesian clay. The magnesium oxide and other components in the magnesian clay can undergo a solid-phase reaction with silica, alumina, and other components in the recycled clay at high temperatures, generating eutectic compounds such as magnesium aluminosilicates. This promotes liquid-phase sintering, effectively fills the interparticle gaps, and improves the density and strength of the ceramic sand. This ratio ensures a moderate amount of liquid phase, achieving good densification without causing product deformation or uneven performance due to excessive flow; it is an optimized and verified golden ratio.

[0016] In a preferred embodiment, the thermal activation treatment involves calcining the recycled clay at 650℃-750℃ for 1-2 hours. Within this temperature range, the interlayer structural water (hydroxyl groups) of the minerals is removed, disrupting the long-range order of the crystal structure and forming short-range ordered metakaolinite. This process releases a large number of active Al-O and Si-O bonds, resulting in a dramatic increase in the surface energy and chemical potential of the clay. Precise control of the calcination time and temperature ensures a thorough and uniform activation process, allowing these highly active sites to participate more effectively in solid-phase reactions and liquid-phase mass transfer during subsequent sintering, thus promoting densification and strength development of the ceramic body.

[0017] In a preferred embodiment, the surface modification treatment involves wet treatment of the thermally activated clay material using a silane coupling agent solution. Silane coupling agents are molecules with an amphiphilic structure, generally denoted by the formula YR-Si(OR')3. Their working principle involves two steps: First, the siloxane alkyl group (-Si(OR')3) hydrolyzes to silanol (-Si(OH)3) in the wet treatment environment, which then undergoes a dehydration condensation reaction with the hydroxyl groups (-OH) on the surface of the recycled clay particles, forming a strong Si-O-Si covalent bond, thereby anchoring the coupling agent to the clay surface. Second, the organic functional group (Y, such as amino or epoxy groups) at the other end of the coupling agent is exposed. These groups can chemically react or physically entangle with components in the subsequent cementitious binder. In this way, a strong chemical interface is established between the inorganic ceramic sand particles and the inorganic / organic composite binder.

[0018] In a preferred embodiment, the magnesian clay is Liling magnesian clay with a magnesium oxide content of 8%-12%.

[0019] In a preferred embodiment, the magnesian clay is activated by acid leaching with a 3%-5% dilute hydrochloric acid solution before use. Hydrochloric acid, as a moderately strong acid, activates the clay primarily through chemical purification and surface corrosion. First, hydrochloric acid reacts with common carbonate impurities in the clay (such as CaCO3 and MgCO3) to generate soluble chlorides and carbon dioxide gas, thereby removing them and preventing the formation of pores due to carbonate decomposition at high temperatures. Second, hydrochloric acid partially dissolves and removes free iron and aluminum oxides, mitigating their adverse effects on the ceramic color. More importantly, the acid solution has a slight corrosive and exfoliating effect on the edges of the clay's layered structure, which not only exposes more fresh surfaces and active sites but also, to some extent, breaks up particle agglomerations, improving its dispersibility in the formulation and ultimately promoting a uniform sintering reaction.

[0020] In a preferred embodiment, the formulation also includes 0.1%-0.5% nano-zinc oxide by weight of the total raw materials. The working principle of this nano-zinc oxide is based on its nano-size effect and high surface activity. First, due to its extremely small particle size (typically <100nm) and huge specific surface area, its surface atoms possess extremely high unsaturated bonds and energy, enabling it to undergo strong solid-state reactions with surrounding SiO2, Al2O3, etc., in the early stages of sintering. This significantly reduces the activation energy of the reaction, promotes the formation of a low-temperature liquid phase, and thus plays a powerful sintering-driving role. Second, in the later stages of sintering, some Zn... 2+Ions can dissolve into the lattice of the main crystalline phase (such as mullite and cristobalite), causing lattice distortion and resulting in solid solution strengthening. At the same time, undissolved nano-ZnO particles accumulate at the grain boundaries, inhibiting abnormal grain growth through the "Zener pinning effect," making the ceramic structure more uniform and dense, reducing microscopic defects, and macroscopically manifesting as a simultaneous improvement in strength and toughness.

[0021] In a preferred embodiment, the formulation also includes boric acid at a weight of 0.1%-0.3% of the total raw materials. Boric acid (H3BO3) first dehydrates during heating to become boric anhydride (B2O3). B2O3 itself has a very low melting point (approximately 450℃) and can rapidly form a eutectic borosilicate glass with SiO2, alkali metal oxides, etc., in the formulation system. Its working principle is: 1) Low-temperature phase formation: Before the main silicate phase forms in large quantities, the borosilicate glass phase begins to form and flow, acting as a "binder" to connect the particles in advance and accelerate the densification process; 2) Mass transfer medium: This glass phase is a good medium for ion migration and can significantly accelerate the dissolution-precipitation process of substances such as SiO2 and Al2O3. 3) Structural buffer: The borosilicate glass phase ultimately exists between grain boundaries. Because its coefficient of thermal expansion is usually lower than that of silicate glass, it can effectively regulate the overall thermal expansion behavior of the ceramic body, reduce the internal stress caused by temperature changes, and the glass phase itself can dissipate the energy at the crack tip through minute viscous flow, thus giving the ceramic sand excellent thermal shock resistance. This achieves the goals of "low-temperature rapid firing" and "high strength and high toughness".

[0022] Compared with the prior art, the technical effects of the present invention are: (1) It achieves the unity of high performance and low cost. Specifically, it mainly uses the waste material (recycled mud) in the process of electric porcelain production as the main raw material, which greatly reduces the raw material procurement cost and solves the problem of high cost caused by the reliance on high-priced minerals in traditional formulas; at the same time, by performing the necessary pretreatment of "thermal activation and surface modification" on the recycled mud, the chemical activity and interfacial compatibility of the waste material are effectively improved, thereby ensuring that the final porcelain sand product has mechanical strength and bonding force with adhesives that are comparable to or even better than those of traditional formulas, thus realizing the high-value resource utilization of waste materials;

[0023] (2) The wet treatment with silane coupling agent solution specifically solves the problem of weak interfacial bonding between recycled material and cement binder. After treatment with silane coupling agent, the surface of recycled mud particles changes from hydrophilic to partially organic (enhanced hydrophobicity). At the same time, functional groups that can form chemical bonds or strong hydrogen bonds with inorganic materials (silica, silicates) and organic materials (some groups in cement hydration products) are introduced, thereby building a strong "bridge" between ceramic sand and binder, which significantly improves the overall mechanical load capacity and long-term reliability of the insulator.

[0024] (3) By introducing local inexpensive raw materials with specific chemical composition and natural mineral structure, the stability and predictability of the formula are ensured; the impurity composition and sintering characteristics of the clay with this specific magnesium content in Liling area have been verified by long-term practice; the magnesium oxide (MgO) content in this range can provide sufficient magnesium source to generate beneficial magnesium aluminum silicate phases (such as cordierite and forsterite precursors) in sintering, improve the thermal stability and mechanical properties of the ceramic body, and will not cause excessive shrinkage or generate harmful phases due to excessive MgO content. It is the key choice to achieve the optimization of cost and performance.

[0025] (4) Purifying and pre-activating the clay raw materials further improves the uniformity and repeatability of the formula performance; acid leaching can effectively dissolve free carbonates, some iron and titanium oxides and other impurities in the clay, reducing the generation of bubbles or colored spots by these impurities at high temperatures, thereby improving the uniformity of the appearance and the internal quality of the ceramic sand. At the same time, acid treatment can partially erode the surface of the clay particles, increasing their specific surface area and reactivity, so that they react more fully and uniformly in subsequent mixing and sintering;

[0026] (5) Using nano zinc oxide as a high-efficiency sintering aid and grain boundary strengthener, the microstructure and macro properties of ceramic sand are significantly improved with a very small amount of addition; nano zinc oxide can effectively reduce the sintering temperature of the formula and save energy; at the same time, it can be evenly distributed at the grain boundary, refine the grains, and strengthen the grain boundary through solid solution strengthening, pinning effect and other methods, thereby greatly improving the compressive strength, flexural strength and wear resistance of ceramic sand, and its strengthening effect is far greater than that of conventional micron-level additives;

[0027] (6) Boric acid is used as a highly efficient flux and glass phase forming agent to further optimize the sintering process and improve the thermal shock resistance of the ceramic sand. Boric acid can decompose at a lower temperature to form a borosilicate glass phase. This liquid phase has low viscosity and good fluidity, which can effectively wet and encapsulate solid particles, promote mass transfer, and enable the ceramic body to achieve high densification at a lower temperature or in a shorter time. At the same time, the formed borosilicate glass phase has a low coefficient of thermal expansion and good elasticity, which helps to buffer thermal stress and improve the ability of the ceramic sand to resist rapid heating and cooling. Detailed Implementation

[0028] To enable those skilled in the art to better understand the technical solution, the present invention will be described in detail below with reference to embodiments. The description in this part is only exemplary and explanatory, and should not be used to limit the scope of protection of the present invention in any way.

[0029] Example 1:

[0030] A high-strength spherical ceramic sand formula for electrical porcelain insulators is made from the following raw materials by weight percentage: pretreated recycled clay: 75%, acid-activated magnesia clay: 25%, without the addition of nano zinc oxide and boric acid;

[0031] Preparation and pretreatment of the above raw materials:

[0032] 1) Pretreatment of recycled mud: Recycled mud that leaked into the mud pool during the pressing process of electric porcelain insulator blanks from Hunan Lide Electric Porcelain Co., Ltd. was dehydrated by pressure filtration, dried, crushed, and passed through a 100-mesh sieve. The sieve material was placed in a muffle furnace and calcined at 700℃ for 1.5h to obtain thermally activated recycled mud. The thermally activated mud was mixed with a 0.8% γ-aminopropyltriethoxysilane (KH-550) aqueous solution at a solid-liquid ratio of 1:2 and stirred at 60℃ for 1h. Then it was filtered, dried, ground, and passed through a 200-mesh sieve to obtain pretreated recycled mud A.

[0033] 2) Magnesia clay pretreatment: Magnesia clay from Liling, Hunan (chemical analysis showed that its magnesium oxide content was 10.2%) was crushed and passed through a 100-mesh sieve. 3 kg of the sieve material was taken and 6 L of 5% dilute hydrochloric acid solution was added. The mixture was stirred and leached at 55℃ for 40 min. Then it was filtered, washed with deionized water until neutral, dried, and ground through a 200-mesh sieve to obtain acid-activated magnesia clay.

[0034] A process for preparing spherical ceramic sand for high-strength electrical porcelain insulators:

[0035] The pretreated recycled mud and acid-activated magnesium clay were mixed in the above proportion, and an appropriate amount of water (30% of the total dry weight) was added as a granulation wetting agent. The mixture was mixed evenly in a roller mill, and then granulated using a disc granulator to obtain spherical green granules with a particle size of 1.0-2.0 mm. The green granules were placed in a drying oven and dried at 105°C to constant weight.

[0036] The dried green pellets are loaded into an electric kiln and sintered according to the following gradient sintering process:

[0037] First stage: Increase the temperature from room temperature to 300℃ at a rate of 1℃ / min, and hold for 30min;

[0038] Second stage: Increase the temperature from 300℃ to 900℃ at a rate of 3℃ / min;

[0039] Third stage: Continue to heat to 1200℃ at a rate of 2℃ / min, and hold for 1 hour;

[0040] Cooling stage: The temperature is slowly reduced to 800℃ at a rate of 1.5℃ / min, and then cooled to room temperature with the furnace to obtain spherical ceramic sand products.

[0041] The above products underwent chemical composition analysis using X-ray fluorescence spectrometry (XRF). The results are as follows: Chemical composition (wt%): Loss on ignition (IL) 7.34, SiO2 51.55, Al2O3 33.97, K2O 2.85, Na2O 0.45, CaO 0.35, MgO 2.38; Microstructure analysis: The cross-sectional morphology was observed using scanning electron microscopy (SEM); Microstructure: SEM showed that the ceramic sand structure was dense, with low porosity, uniform grain size (2-5 μm), and clear grain boundaries.

[0042] Example 2:

[0043] A high-strength spherical ceramic sand formula for electrical porcelain insulators is made from the following raw materials by weight percentage: pretreated recycled mud: 74.5%, acid-activated magnesia clay: 25%, and nano zinc oxide (average particle size 30nm): 0.5%.

[0044] The pretreatment methods for recycled mud and magnesian clay are exactly the same as those in Example 1, resulting in pretreated recycled mud and acid-activated magnesian clay, respectively.

[0045] A process for preparing spherical ceramic sand for high-strength electrical porcelain insulators:

[0046] First, prepare a 5% suspension of nano zinc oxide with a small amount of water and ultrasonically disperse it for 30 minutes. Then, mix the pretreated recycled mud and acid-activated magnesium clay, and add the nano zinc oxide suspension while stirring to ensure uniform dispersion of nanoparticles. The subsequent granulation, drying and sintering processes are the same as in Example 1 to obtain spherical ceramic sand products.

[0047] Microstructure analysis of the above products revealed that SEM showed finer grains (1-3 μm) and uniformly distributed nano-zinc oxide particles at the grain boundaries, which acted as "pinning".

[0048] Example 3:

[0049] A high-strength spherical ceramic sand formula for electrical porcelain insulators is made from the following raw materials in weight percentages: pretreated recycled mud: 74.7%, acid-activated magnesia clay: 25%, nano zinc oxide (average particle size 30nm): 0.2%, boric acid: 0.1%.

[0050] The pretreatment methods for recycled mud and magnesian clay are exactly the same as those in Example 1, resulting in pretreated recycled mud and acid-activated magnesian clay, respectively.

[0051] A process for preparing spherical ceramic sand for high-strength electrical porcelain insulators: Boric acid is dissolved in a small amount of warm water to prepare a saturated solution. Pretreated recycled mud and acid-activated magnesium clay are mixed evenly, then the boric acid solution is added and mixed evenly. Then, an ultrasonically dispersed nano-zinc oxide suspension (preparation method is the same as in Example 2) is added. The subsequent granulation and drying processes are the same as in Example 1 to obtain the spherical ceramic sand product.

[0052] The sintering process has been slightly adjusted:

[0053] The peak sintering temperature was reduced to 1180°C (20°C lower than in Example 1), while other gradient sintering parameters remained unchanged.

[0054] Microstructure analysis of the above products revealed that the structure was highly dense with very few pores, narrow grain size distribution (1-2 μm), and a small amount of glass phase was visible at the grain boundaries.

[0055] Comparative Example 1:

[0056] Traditional high-priced raw material formula for spherical ceramic sand:

[0057] A high-strength spherical ceramic sand formula for electrical porcelain insulators is made from the following raw materials by weight percentage:

[0058] Hunan feldspar: 30%;

[0059] High-quality kaolin from Shanxi: 35%;

[0060] Henan bauxite: 20%;

[0061] Talc: 15%.

[0062] A preparation process for spherical ceramic sand for high-strength electrical porcelain insulators: After the raw materials are mixed, the same granulation, drying and sintering process as in Example 1 is adopted (the peak sintering temperature is 1220℃).

[0063] Comparative Example 2:

[0064] A high-strength spherical ceramic sand formula for electrical porcelain insulators is made from the following raw materials by weight percentage: untreated recycled clay: 75%, acid-activated magnesium clay: 25%. Microstructural analysis of the above product revealed a relatively loose structure with numerous and unevenly distributed pores and varying grain sizes, as shown by SEM.

[0065] Raw material preparation:

[0066] Take the same recycled mud as in Example 1, but do not perform thermal activation and surface modification treatment. It is used directly after drying, crushing and sieving (200 mesh), and is marked as untreated recycled mud.

[0067] The same acid-activated magnesium clay as in Example 1 was used for the magnesium clay.

[0068] A preparation process for spherical ceramic sand for high-strength electrical porcelain insulators: exactly the same as in Example 1, to obtain spherical ceramic sand products.

[0069] Comparative Example 3:

[0070] A high-strength spherical ceramic sand formula for electrical porcelain insulators is made from the following raw materials by weight percentage: thermally activated clay only: 75%, acid-activated magnesia clay: 25%.

[0071] Raw material preparation:

[0072] The recycled mud was only thermally activated (calcined at 700℃ for 1.5h) but not surface modified with silane coupling agent, and was marked as thermally activated mud only.

[0073] The same acid-activated magnesium clay B as in Example 1 was used for the magnesium clay.

[0074] A preparation process for spherical ceramic sand for high-strength electrical porcelain insulators: the same as in Example 1, to obtain spherical ceramic sand products.

[0075] Comparative Example 4:

[0076] The difference between this comparative example and Example 1 is that ordinary clay is used instead of Liling magnesian clay in the formulation. The magnesian clay used is ordinary building clay (produced in Changsha, chemical analysis shows that the MgO content is only 2.3%), which is treated with the same acid leaching and labeled as ordinary clay. The rest of the preparation process is the same as in Example 1.

[0077] Comparative Example 5:

[0078] The difference between this comparative example and Example 3 is that the formulation is: 73% pretreated recycled mud, 25% acid-activated magnesia clay, 1.5% nano zinc oxide, and 0.5% boric acid. The remaining preparation process is the same as in Example 3. Microstructural analysis of the above product revealed that SEM showed excessive liquid phase leading to abnormal grain growth (some reaching 15 μm) and an uneven structure.

[0079] The spherical ceramic sand products obtained in Examples 1-3 and Comparative Examples 1-5 were subjected to performance tests. Physical performance tests included: compressive strength tested according to GB / T 6569-2006; bulk density and water absorption tested according to GB / T 8489-2006; and the average linear expansion coefficient (20-600℃) tested using a thermal expansion meter. Application performance tests involved applying the ceramic sand to the adhesive bonding area of ​​a 20028 type electrical porcelain insulator blank according to standard procedures. After firing the finished product, its electromechanical breaking load was tested according to GB / T 775.3-2006. The test results are shown in the table below.

[0080] Table 1. Test results of physical and application properties of ceramic sand products

[0081] It should be noted that, in this document, the terms "comprising," "including," and any other variations are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Specific examples have been used in this document to illustrate the principles and implementation methods of the present invention. These examples are merely for the purpose of helping to understand the method and core ideas of the present invention. The above descriptions are only preferred embodiments of the present invention. It should be pointed out that, due to the limitations of written expression and the objective existence of infinite specific structures, those skilled in the art can make several improvements, modifications, or variations without departing from the principles of the present invention, and can also combine the above technical features in an appropriate manner. These improvements, modifications, variations, or combinations, or the direct application of the concept and technical solution of the present invention to other situations without modification, should all be considered within the scope of protection of the present invention.

Claims

1. A spherical porcelain sand formulation for high strength electric porcelain insulators, characterized by, The raw materials are prepared by the following weight percentages: Pre-treated recycled mud 70%-80%; Magnesia clay 20%-30%; The pre-treated recycled mud is mud recovered in the mud pressing process of an electric porcelain insulator blank body mud, which is obtained by heat activation and surface modification treatment.

2. A ball-form ceramic sand formulation for high strength electric porcelain insulator as claimed in claim 1, wherein, The weight percentages of the raw materials are: pre-treated recycled mud 75%, and magnesia clay 25%.

3. A ball-form ceramic sand formulation for high strength electric porcelain insulator as claimed in claim 1, wherein, The heat activation treatment is: calcining the recycled mud at 650-750℃ for 1-2h.

4. A ball-form ceramic sand formulation for high strength electric porcelain insulator as claimed in claim 1, wherein, The surface modification treatment is: wet treatment of the heat-activated mud with a silane coupling agent solution.

5. A ball-form ceramic sand formulation for high strength electric porcelain insulator as claimed in claim 1 or 2, wherein, The magnesia clay is Liling magnesia clay with a magnesium oxide content of 8%-12%.

6. A ball-form ceramic sand formulation for high strength electric porcelain insulator as claimed in claim 5, wherein, The magnesia clay is activated by acid immersion with a dilute hydrochloric acid solution with a concentration of 3%-5% before use.

7. A ball-form ceramic sand formulation for high strength electric porcelain insulator according to claim 1 or 2, characterized in that, The formula further includes 0.1%-0.5% of nano-zinc oxide based on the total weight of the raw materials.

8. A ball-form ceramic sand formulation for high strength electric porcelain insulator as claimed in claim 1 or 2, wherein, The formula further includes 0.1%-0.3% of boric acid based on the total weight of the raw materials.

Images