Bio-based composite activating auxiliary agent for producing active calcium phosphate by utilizing renewable resources as well as preparation method and application of bio-based composite activating auxiliary agent

Abstract

The invention discloses a bio-based composite activating aid for producing active calcium phosphate by utilizing renewable resources as well as a preparation method and application of the bio-based composite activating aid, and belongs to the technical field of active calcium phosphate preparation. The bio-based composite active auxiliary agent is prepared from the following raw material components in parts by mass: 20 to 40 parts of bio-based organic acid or bio-based organic acid salt, 15 to 30 parts of polysaccharide or a derivative thereof, 25 to 45 parts of alkali metal silicate and 5 to 15 parts of alkali metal carbonate. According to the invention, the bio-based composite activating auxiliary agent is prepared through synergism of multiple components, and the bio-based composite activating auxiliary agent is matched with the phosphorus-containing solid waste to prepare the active calcium phosphate, so that integration of high-valued renewable resources, high performance of the active calcium phosphate and performance upgrading of electronic ceramics is realized, meanwhile, the auxiliary agent is ensured to be green and non-toxic, and is adaptive to various scenes, and the production cost and the environmental risk are reduced.

Description

Technical Field

[0001] This invention relates to the field of active calcium phosphate preparation technology, and in particular to a bio-based composite activating agent for producing active calcium phosphate using renewable resources, its preparation method, and its application. Background Technology

[0002] Activated calcium phosphate (mainly composed of α-tricalcium phosphate, α-TCP) is widely used in traditional fields due to its good biocompatibility and reactivity. With the development of the electronic ceramics industry, its low impurity and high stability characteristics have gradually attracted attention. Traditional activated calcium phosphate production mostly uses high-purity chemical reagents as raw materials, resulting in high costs and low resource utilization. Phosphorus-containing solid waste (such as phosphorus-containing waste liquid, sludge, and retired battery waste) is used as a renewable resource, with a phosphorus content of 10%-30%, but its complex composition and heavy metal impurities lead to problems such as high dehydroxylation temperature, unstable α-TCP crystal phase, and excessive heavy metals in the prepared activated calcium phosphate, making it difficult to meet the requirements of high-end applications (such as the purity requirements of electronic ceramic raw materials). Existing activation aids are mostly single-function, only able to solve the problems of dehydroxylation or crystal phase control, and cannot simultaneously address heavy metal solidification and high-end product performance; moreover, some aids contain harmful components, which can easily lead to secondary pollution of the product, failing to meet the stringent purity requirements of electronic ceramics raw materials.

[0003] Electronic ceramics are key materials that achieve new functions through precise control of surface, grain boundaries, and dimensional structure. They are widely used in energy, home appliances, and automotive fields, and are indispensable, especially in transistor components and new energy vehicle battery systems. Transistors rely on the insulation and low magnetic properties of ceramic substrates to achieve stable signal transmission, while ceramic-coated separators and sealed connectors used in new energy vehicle batteries require ceramic materials with excellent high-temperature resistance, corrosion resistance, and safety (such as delaying thermal runaway). Although current electronic ceramic raw materials (such as alumina and aluminum nitride) can meet some of the needs, they suffer from high costs, high energy consumption in the preparation process, and limited performance characteristics (such as insufficient wear resistance and difficulty in controlling radiation). Activated calcium phosphate, if its performance can be improved through modification, can serve as a low-cost, green supplement to electronic ceramic raw materials. However, existing activated calcium phosphate is unsuitable for direct application due to low purity and unstable performance. Therefore, it is urgent to regulate its performance with specialized additives to adapt it to the needs of electronic ceramic production.

[0004] The above analysis reveals two key issues: firstly, the preparation of activated calcium phosphate from phosphorus-containing solid waste lacks activating agents that simultaneously achieve "greenness, high activity, and low impurities"; secondly, electronic ceramic raw materials lack novel components that combine "multi-performance enhancement (wear resistance, high temperature resistance, low radiation, etc.) + low cost + environmental friendliness." This technological gap restricts the high-value utilization of recycled resources and the upgrading of the electronic ceramics industry. Therefore, developing a bio-based composite activating agent capable of preparing high-performance activated calcium phosphate (suitable for electronic ceramic requirements) is crucial to overcoming these bottlenecks. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a bio-based composite activating agent for producing active calcium phosphate using recycled resources, along with its preparation method and applications. This invention utilizes a multi-component synergistic preparation of the bio-based composite activating agent, which is then combined with phosphorus-containing solid waste for the production of active calcium phosphate. This achieves an integrated process of "high-value utilization of recycled resources - high-performance active calcium phosphate - performance upgrade of electronic ceramics," while ensuring the agent is green and non-toxic, adaptable to various scenarios, and reduces production costs and environmental risks.

[0006] The technical solution of the present invention is as follows: The first aspect of this invention protects a bio-based composite active agent, which, by mass parts, comprises the following raw material components: 20-40 parts of bio-based organic acid or bio-based organic acid salt, 15-30 parts of polysaccharide or its derivative, 25-45 parts of alkali metal silicate, and 5-15 parts of alkali metal carbonate.

[0007] Preferably, the bio-based organic acid includes at least one of citric acid, gluconic acid, and low molecular weight humic acid. Preferably, the molecular weight of the low molecular weight component of the humic acid is 500~3000 Da, and the molar ratio of carboxyl groups to phenolic hydroxyl groups is 2:1~3:1; The bio-based organic acid salts include at least one of citrate and gluconate.

[0008] Preferably, the polysaccharide or its derivative includes at least one of sodium carboxymethyl cellulose, sodium alginate, and modified starch; Preferably, the modified starch includes at least one of hydroxypropyl starch and acetate starch.

[0009] Preferably, the alkali metal silicate includes sodium silicate; Preferably, the modulus of the sodium silicate is 2 to 3, and / or, At 20℃, the viscosity of a 5% sodium silicate aqueous solution is 20~50 mPa·s; The alkali metal carbonate is at least one of sodium carbonate and potassium carbonate.

[0010] A second aspect of this invention protects a method for preparing the bio-based composite active agent described in the first aspect, comprising the following steps: The bio-based organic acid or bio-based organic acid salt, the polysaccharide or polysaccharide derivative, the alkali metal silicate, and the alkali metal carbonate in the specified amounts are placed in a double helix mixing device, mixed, and then pulverized to obtain the final product. Preferably, the mixing speed is 150~200 r / min and the time is 10~15 min; The particle size of the bio-based composite active agent is 200-300 mesh.

[0011] A third aspect of this invention protects a method for producing activated calcium phosphate from phosphorus-containing waste, comprising the following steps: S1: Mix the phosphorus-containing waste with a bio-based composite active agent to obtain a premix; S2: Calcine the premixed material to obtain the calcined product; S3: Grind and sieve the calcined product to obtain active calcium phosphate.

[0012] Preferably, in step S1, the phosphorus-containing waste includes at least one of phosphorus-containing waste liquid, phosphorus-containing sludge, and phosphorus-containing battery waste. The bio-based composite active agent is the bio-based composite active agent described in the first aspect above, or the bio-based composite active agent prepared by the preparation method described in the second aspect above. The amount of the bio-based composite active additive added is 0.5-2.0% of the weight of the phosphorus-containing waste material; The mixing speed is 200~300 r / min, and the time is 15~20 min; In step S2, the calcination temperature is 900~1200℃ and the time is 2~4 h; In step S3, the particle size of the active calcium phosphate is 38~53 μm.

[0013] Preferably, before grinding in step S3, the following steps are also included: Take 0.1-0.3% of the bio-based composite active agent by weight of the phosphorus-containing waste material, add water and mix to obtain an aqueous solution of the bio-based composite active agent with a mass concentration of 5-10%. A 5-10% (w / w) aqueous solution of bio-based composite active additives was applied by high-pressure spraying to the surface of the calcined product obtained in step S2, and allowed to stand for 5-10 minutes. Preferably, the pressure of the high-pressure spray is 0.6~1.0MPa and the nozzle diameter is 0.4~0.6mm.

[0014] A fourth aspect of this invention protects an active calcium phosphate prepared by the method described in the third aspect above, wherein the active calcium phosphate contains ≥90% by mass of α-tricalcium phosphate; the impurity content is ≤0.01%; and / or, The volume resistivity of the active calcium phosphate is ≥1×10⁻⁶. 14 Ω cm.

[0015] The fifth aspect of this invention protects an electronic ceramic, said electronic ceramic comprising activated calcium phosphate; The active calcium phosphate in the electronic ceramic has a mass fraction of 5-15%; The active calcium phosphate is the active calcium phosphate described in the fourth aspect above, or the active calcium phosphate prepared by the preparation method described in the third aspect above.

[0016] The beneficial technical effects of this invention are as follows: This invention prepares a multifunctional bio-based composite activator by compounding bio-based organic acids or their salts, polysaccharides or their derivatives, alkali metal silicates, and alkali metal carbonates in a specific ratio. This not only solves the core problems in the traditional preparation of activated calcium phosphate from phosphorus-containing waste, such as high dehydroxylation temperature, unstable α-TCP crystal phase, and excessive heavy metals, but also endows activated calcium phosphate with high insulation and high dispersibility, which are suitable for electronic ceramics. This successfully expands activated calcium phosphate from traditional application fields to the field of electronic ceramic raw materials, while making up for the shortcomings of high cost and single performance of existing electronic ceramic raw materials, and achieving an integrated breakthrough of "high-value recycling of renewable resources - high-performance activated calcium phosphate - performance upgrade of electronic ceramics".

[0017] The additives described in this invention work synergistically with phosphorus-containing waste to produce high-purity, highly active calcium phosphate through calcination and subsequent processes. This process combines environmental value with performance advantages: First, it enables the resource utilization of phosphorus-containing solid waste, transforming phosphorus-containing waste liquids, sludge, and battery waste into high-value products, improving raw material utilization while reducing raw material costs, aligning with green chemistry principles. Second, each component works synergistically and precisely: the carboxyl and phenolic hydroxyl groups of bio-based organic acids and their salts can react with calcium... 2+ Pre-coordinated weakening of the Ca-O bond in hydroxyapatite (HA) lowers the dehydroxylation temperature and forms stable complexes with heavy metal ions, preventing them from entering the active calcium phosphate lattice. Furthermore, complete decomposition at high temperatures leaves no residue, ensuring product purity. The long polymer chains of polysaccharides and their derivatives create steric hindrance, preventing particle agglomeration and ensuring uniform particle size distribution of active calcium phosphate, laying the foundation for the compactness of electronic ceramic molding. The temporary carbonaceous framework formed by its pyrolysis also guides the crystal to form a porous, small-sized structure, improving product activity and dispersibility. Alkali metal silicates melt at high temperatures to form a silicate glass, encapsulating the pre-fixed heavy metals into a stable solid solution for deep solidification. Simultaneously, they form a composite structure with calcium phosphate, enhancing the product's high-temperature resistance and insulation. Alkali metal carbonates lower the eutectic point of the system, promoting Ca2+ ionization. 2+ PO4 3- Ion diffusion increases the relative content of the α-TCP crystalline phase.

[0018] The active calcium phosphate prepared by this invention has an α-TCP content ≥90%, an activity improvement of 20%-40%, and a dispersibility improvement of 30%-50%. It also possesses low impurities (≤0.01%), high temperature resistance (1200~1400 ℃), and high insulation (≥1×10⁻⁶). 14 Ω (cm), breaking through the application limitations of traditional active calcium phosphate and expanding into the field of electronic ceramics.

[0019] In addition, the active calcium phosphate of the present invention, when added as a raw material for electronic ceramics, can reduce ceramic wear by 25% to 40%, increase the upper limit of high temperature resistance by 20% to 30%, reduce the mass loss rate of acid and alkali immersion by ≤0.5%, reduce radiation by ≤0.1 μSv / h, and reduce magnetic permeability by ≤1.05. This not only meets the requirements of transistors for insulation and signal stability, but also helps to improve the safety of ceramic components in new energy vehicle batteries (such as synergistically extending the thermal runaway trigger time), while reducing the cost of electronic ceramic raw materials by 15% to 25%. Attached Figure Description

[0020] Figure 1 This is a scanning electron microscope image of the active calcium phosphate material in Example 1 of the present invention.

[0021] Figure 2 This is an X-ray diffraction pattern of the active calcium phosphate material in Example 1 of the present invention.

[0022] Figure 3 The image shows the infrared spectrum of the active calcium phosphate material in Example 1 of this invention. Detailed Implementation

[0023] The present invention will now be described in detail with reference to the embodiments.

[0024] To address the problems of high dehydroxylation temperatures, unstable α-TCP crystal phase, and excessive heavy metals in the preparation of activated calcium phosphate from phosphorus-containing solid waste, the use of existing activators with limited functionality and some containing harmful components that do not meet the purity requirements of electronic ceramics, and the unstable performance of existing activated phosphates that cannot be directly used in electronic ceramics, while existing electronic ceramic raw materials are expensive and have limited performance, this invention provides a bio-based composite activator for producing activated calcium phosphate using recycled resources to solve the above problems.

[0025] The first aspect of the present invention provides a bio-based composite active adjuvant, which comprises the following raw material components in parts by mass: 20-40 parts of bio-based organic acid or bio-based organic acid salt, 15-30 parts of polysaccharide or its derivative, 25-45 parts of alkali metal silicate, and 5-15 parts of alkali metal carbonate.

[0026] The bio-based composite activator of the present invention is composed of bio-based organic acids or their salts, polysaccharides or their derivatives, alkali metal silicates, and alkali metal carbonates in a specific ratio, which not only solves the fundamental problem of the preparation of active calcium phosphate, but also endows it with electronic ceramic compatibility.

[0027] In some embodiments, the bio-based organic acid includes at least one of citric acid, gluconic acid, and low molecular weight humic acid.

[0028] In some embodiments, the molecular weight of the low molecular weight humic acid component is 500~3000 Da, and the molar ratio of carboxyl groups to phenolic hydroxyl groups is 2:1~3:1.

[0029] The bio-based organic acid salts include at least one of citrate and gluconate, exemplarily including sodium citrate, magnesium gluconate, etc.

[0030] It is understandable that the carboxyl group (-COO) in bio-based organic acid molecules - ) and / or phenolic hydroxyl groups (-Ar-OH) act as polydentate ligands, which can, on the one hand, react with Ca 2+ Pre-coordination weakens the Ca-O bonds in hydroxyapatite (HA) already present in phosphorus-containing waste or formed during the initial calcination stage, lowering the dehydroxylation temperature to below 900℃ and reducing energy consumption. Coordination can lay the foundation for the directed formation of α-TCP through an indirect pathway of 'weakening Ca-O bonds → promoting dehydroxylation → optimizing the ion diffusion environment': First, the carboxyl group (and the phenolic hydroxyl group of humic acid) reacts with Ca... 2+ After pre-coordination, the crystal structure stability of HA decreases, and the dehydroxylation reaction (HA → tricalcium phosphate precursor) is more likely to occur, avoiding the problems of incomplete dehydroxylation and residual impurities caused by the structural stability of HA in traditional processes; secondly, coordination can fix Ca 2+ The local coordination environment allows Ca to be properly coordinated during calcination. 2+ With PO4 3- The bonding becomes more directional, reducing the formation of unstable impurities such as β-TCP; third, during the high-temperature calcination stage, the coordination bonds break, releasing active Ca. 2+ With PO4 3- Under the synergistic effect of alkali metal carbonates (lowering the eutectic point) and alkali metal silicates (constructing a composite structure), directional polymerization forms the α-TCP crystalline phase. On the other hand, it can react with heavy metal ions (Pb... 2+ Cd 2+ (etc.) to form stable complexes, preventing heavy metals from entering the active calcium phosphate lattice and ensuring product purity (impurity content ≤0.01%), laying the foundation for low radiation and low magnetism in subsequent electronic ceramics. In addition, the bio-based organic acid is completely decomposed into CO2 and H2O at high temperatures, with no carbon residue, further ensuring product cleanliness.

[0031] In some embodiments, the polysaccharide or its derivatives include at least one of sodium carboxymethyl cellulose (CMC), sodium alginate, and modified starch.

[0032] In some embodiments, the modified starch includes at least one of hydroxypropyl starch and acetate starch, preferably with a degree of substitution of 0.05-0.2 for its substituents.

[0033] It is understood that the long polymer chains contained in the polysaccharides or their derivatives used in this invention can form steric hindrance during the dry mixing stage of the additives and phosphorus-containing waste, preventing the agglomeration of material particles and laying a foundation for uniform dispersion in subsequent calcination and grinding processes. In the early stage of calcination, the polysaccharides or their derivatives pyrolyze to form a temporary carbonaceous skeleton, which can guide the calcium phosphate crystals to form a porous, small-sized structure (particle size 1-5 μm), increasing the specific surface area to enhance the product's reactivity. In the subsequent grinding and high-pressure spraying (if used), the residual polymer fragments can still play a dispersing role, ultimately making the active calcium phosphate particle size distribution uniform (span 0.7-0.9), which not only ensures the density required for electronic ceramic molding, but also allows for more uniform micro-dispersion when active calcium phosphate is mixed with ceramic raw materials, avoiding local performance differences and ensuring the structural consistency and performance stability of electronic ceramics.

[0034] In some embodiments, the alkali metal silicate includes sodium silicate (Na2O·nSiO2, where n is the silicon-to-oxygen ratio, ranging from 1.5 to 3.5).

[0035] In some embodiments, the modulus (molar ratio of SiO2 to Na2O) of the sodium silicate is 2.0 to 3.0.

[0036] In some embodiments, the viscosity of a 5% sodium silicate aqueous solution at 20°C is 20-50 mPa·s.

[0037] Understandably, sodium silicate (Na2O·nSiO2) with a modulus of 2.0 to 3.0 is selected. When it melts at high temperature to form a silicate glass, it can encapsulate heavy metal ions that are coordinated and fixed by bio-based organic acids into a stable silicate solid solution (heavy metal leaching rate ≤0.1 mg / L), thus achieving deep solidification of heavy metals. In particular, for phosphorus-containing solid waste with high heavy metal content (such as nickel total 608 mg / kg, chromium total 266 mg / kg, lead total 39.2 mg / kg), deep solidification of heavy metals is achieved through a dual mechanism of "coordination pre-fixation-vitrification encapsulation", realizing "waste treatment with waste" and reducing production costs and environmental pollution. On the other hand, sodium silicate with a modulus of 2.0 to 3.0 can form a "calcium phosphate-silicate" composite structure with calcium phosphate crystals. This structure can improve the high-temperature resistance of active calcium phosphate (active calcium phosphate itself has a high temperature resistance limit of 1400 ℃), thereby improving the high-temperature resistance of electronic ceramics (by 20%-30%). At the same time, the insulating properties of silicate glass can synergistically improve the volume resistivity of active calcium phosphate (≥1×10⁻⁶). 14 Ω (cm), giving electronic ceramics better insulation properties to meet the needs of transistor signal transmission.

[0038] In some embodiments, the alkali metal carbonate is at least one of sodium carbonate and potassium carbonate.

[0039] In some embodiments, the alkali metal carbonates used in this invention, such as sodium carbonate or potassium carbonate, decompose at high temperatures to produce Na₂O / K₂O, which can lower the eutectic point of the system (to 900-1000 °C) and promote Ca... 2+ PO4 3- Ion diffusion increases the α-TCP crystal phase content to over 90%.

[0040] A second aspect of the present invention provides a method for preparing the bio-based composite active agent described in the first aspect above, comprising the following steps: The bio-based organic acid or bio-based organic acid salt, the polysaccharide or polysaccharide derivative, the alkali metal silicate, and the alkali metal carbonate in the prescribed amounts are placed in a double helix mixing device, mixed, and then ultra-finely pulverized to obtain the final product.

[0041] In some embodiments, the double-helix mixing device is a double-helix mixer.

[0042] In some embodiments, the mixing speed is 150-200 r / min and the mixing time is 10-15 min.

[0043] In some embodiments, the particle size of the bio-based composite active agent is 200-300 mesh.

[0044] A third aspect of the present invention provides a method for producing activated calcium phosphate from phosphorus-containing waste, comprising the following steps: S1: Mechanically mix the phosphorus-containing waste with the bio-based composite active additive to ensure microscopic uniform contact between the additive and the phosphorus-containing waste, and obtain a premix; S2: The premixed material is placed in a calcination device and calcined. During the calcination process, the additives act as coordination templates and form with the glass network to complete the α-TCP crystal phase regulation and heavy metal fixation. After cooling, the calcined product is obtained. S3: Grind and sieve the calcined product to obtain active calcium phosphate.

[0045] In some embodiments, in step S1, the phosphorus-containing waste includes at least one of phosphorus-containing waste liquid, phosphorus-containing sludge, and phosphorus-containing battery waste.

[0046] In this invention, phosphorus-containing waste needs to be pretreated according to conventional methods before use to remove mechanical impurities such as gravel and metal scraps, and to convert it into a homogeneous solid raw material before mixing it with additives. The specific pretreatment methods for different types of waste are as follows: Phosphorus-containing sludge: The original phosphorus-containing sludge is first dried at low temperature to a moisture content of ≤15%, then crushed by a jaw crusher, and then screened into particles with a particle size of ≤5mm by a vibrating screen. This step can avoid the wet sludge from clumping, which would lead to uneven mixing of the additives. At the same time, it removes gravel and inert impurities, ensuring that the subsequent mixing and calcination processes are stable and controllable.

[0047] Phosphorus-containing waste liquid: The original phosphorus-containing waste liquid is first treated by plate and frame filter or centrifugal dewatering to obtain filter cake material, and then processed according to the drying, crushing and screening process of phosphorus-containing sludge (drying to moisture content ≤15% and screening into particles with a particle size ≤5mm) to ensure that its morphology is consistent with other phosphorus-containing wastes and is suitable for dry mixing process.

[0048] Phosphorus-containing battery waste: First, dismantle retired phosphorus-containing batteries (such as lithium iron phosphate batteries and lead-acid batteries) to remove non-phosphorus-containing components such as casing metal and electrolyte. Then, crush phosphorus-containing components such as electrode active materials and tab residues to a particle size of ≤10mm. Subsequently, remove ferromagnetic impurities through magnetic separation. Finally, sieve the material into particles with a particle size of ≤5mm to avoid metal impurities affecting the purity of active calcium phosphate and the performance of electronic ceramics.

[0049] The bio-based composite active agent is the bio-based composite active agent described in the first aspect above, or the bio-based composite active agent prepared by the preparation method described in the second aspect above.

[0050] In some embodiments, in step S1, the amount of the bio-based composite active agent added is 0.5 to 2.0% of the amount of the phosphorus-containing waste material.

[0051] In some embodiments, in step S1, the mixing speed is 200~300 r / min and the time is 15~20 min.

[0052] In some embodiments, in step S2, the heating rate of the calcining equipment is 5~10 ℃ / min, the cooling rate is 8~15 ℃ / min, and the equipment is cooled to room temperature before proceeding to subsequent processes.

[0053] In some embodiments, in step S2, the calcination temperature is 900~1200℃ and the time is 2~4 h.

[0054] In some embodiments, in step S3, the grinding is ultra-fine grinding with a fineness of 300-500 mesh, and the sieving is done using a vibrating screen with a screen aperture of 38-53 μm.

[0055] In some embodiments, in step S3, the particle size of the active calcium phosphate is 38~53 μm.

[0056] In some embodiments, to further improve the dispersibility of the product, the following steps are included before grinding in step S3: (1) Take 0.1-0.3% of the bio-based composite active agent by weight of the phosphorus-containing waste material, add water and mix to obtain a bio-based composite active agent aqueous solution with a mass concentration of 5-10%; (2) Apply a 5-10% aqueous solution of bio-based composite active additives evenly to the surface of the calcined product obtained in step S2 using a high-pressure spraying device, and let it stand for 5-10 minutes.

[0057] In some embodiments, the high-pressure spray has a pressure of 0.6~1.0MPa and a nozzle diameter of 0.4~0.6mm.

[0058] Regarding the amount of additives added, when the phosphorus-containing waste contains heavy metals (Pb, Cd, Cu, Zn, Cr)... 3+ When the total content is ≤50mg / kg, the amount of additive added in step (1) is 0.5%~1.0% of the total mass of phosphorus-containing waste; when the total heavy metal content in the phosphorus-containing waste is >50 mg / kg or the α-TCP content of the active calcium phosphate product is required to be ≥90%, the amount of additive added in step (1) is 1.0%~2.0% of the total mass of phosphorus-containing waste.

[0059] A fourth aspect of the present invention provides an active calcium phosphate prepared by the method described in the third aspect above, wherein the active calcium phosphate contains ≥90% by mass of α-tricalcium phosphate; the impurity content is ≤0.01%; and / or, The volume resistivity of the active calcium phosphate is ≥1×10⁻⁶. 14 Ω cm.

[0060] The present invention also provides an electronic ceramic, which includes active calcium phosphate; the active calcium phosphate is the active calcium phosphate described in the fourth aspect above, or the active calcium phosphate prepared by the preparation method described in the third aspect above.

[0061] The active calcium phosphate prepared in this invention contains α-TCP, which has high activity and a stable structure. It can form a tight bond with other raw materials (such as alumina) during the sintering process of electronic ceramics, reduce interface defects, and improve the wear resistance and corrosion resistance of the prepared electronic ceramics. It is especially suitable for wear-prone and corrosion-prone scenarios such as sealing connectors for new energy vehicle batteries.

[0062] In some embodiments, the active calcium phosphate in the electronic ceramic has a mass fraction of 5-15%. This can improve the wear resistance, high temperature resistance, and corrosion resistance of the electronic ceramic, reduce radiation and magnetism, and improve insulation.

[0063] In some embodiments, the electronic ceramics further include alumina and sintering aids. The present invention does not limit the sintering aids in each embodiment, and any sintering aid that can achieve the effects of the present invention is within the protection scope of the present invention.

[0064] In some embodiments, the electronic ceramic is composed of active calcium phosphate and alumina.

[0065] The electronic ceramics of this invention include ceramic components in the energy field, ceramic parts for household appliances, and ceramic parts in the automotive field; the ceramic parts in the automotive field include ceramic substrates for transistors, ceramic-coated separator substrates for new energy vehicle batteries, and ceramic components for sealed connectors.

[0066] The electronic ceramics prepared with the active calcium phosphate described in this invention exhibit 25%-40% lower wear than those prepared with traditional raw materials without the addition of active calcium phosphate, an increased upper limit of high temperature resistance to 1200-1400℃, a mass loss rate ≤0.5% after acid and alkali immersion, an radiation dose ≤0.1 μSv / h, a magnetic permeability ≤1.05, and a volume resistivity ≥1×10⁻⁶. 14 Ω cm.

[0067] The present invention will be further described below through examples and other means.

[0068] Example 1 The preparation method of the auxiliary agent for the preparation of active calcium phosphate includes: Weigh the following components by weight: 30 parts sodium citrate, 20 parts sodium carboxymethyl cellulose (CMC), 40 parts sodium silicate (modulus 2.5), and 10 parts sodium carbonate. Place all raw materials in a twin-screw mixer and mix at 180 r / min for 12 minutes. Then, pulverize the mixture to 250 mesh to obtain powdered additives.

[0069] The above-mentioned additives are used to prepare active calcium phosphate, and the preparation method is as follows: Phosphorus-containing sludge was prepared and pretreated to obtain a phosphorus content of 18%, a calcium content of 24.5%, a total heavy metal content of 45 mg / kg, and a phosphorus content of Pb. 2+ 8 mg / kg, Cd 2+ : 1.2 mg / kg of phosphorus-containing sludge raw material; (1) Add the powdered additive prepared above at 0.8% of the total mass of phosphorus-containing sludge raw material, and mix at 250 r / min for 18 minutes; (2) Heat to 1050 °C at 8 °C / min, hold for 3 hours, and then cool down at 12 °C / min to obtain the calcined product; (3) Take the same powdered additive as above at 0.2% of the total mass of phosphorus-containing sludge raw material and prepare an 8% mass concentration aqueous solution of the additive. Spray the aqueous solution of the additive evenly onto the surface of the calcined material through a high-pressure spraying device. The spraying pressure is 0.8 MPa and the nozzle diameter is 0.5 mm. After spraying, let it stand for 8 minutes to allow the aqueous solution of the additive to fully penetrate into the pores of the material and form a uniform adhesion layer. Then, perform ultra-fine grinding, control the grinding fineness to 300-500 mesh, and use a vibrating screen with a 50 μm aperture to sieve to obtain the active calcium phosphate product.

[0070] The activated calcium phosphate obtained in this example has an α-TCP content of 94.7% and a volume resistivity of 1.5 × 10⁻⁶. 14 Ω cm, impurity content 0.006%. The volume resistivity test method is as follows: using a high resistance meter at an ambient temperature of 25℃ and a relative humidity of 50%, a DC voltage of 1000V is applied to the molded active calcium phosphate sample. After the voltage stabilizes for 1 minute, the test value is read, which is the volume resistivity of the sample.

[0071] The scanning electron microscope image of the active calcium phosphate material obtained in this embodiment is as follows: Figure 1 As shown in the figure, activated calcium phosphate exists in a loose but ordered aggregate form, with fine crystals of approximately 0.2-0.8 μm uniformly attached to its surface. Its XRD pattern is shown below. Figure 2 As shown, from Figure 2 As can be seen from the image, the prepared active calcium phosphate exhibits high intensity and sharp peak shape in its characteristic diffraction peaks. The infrared spectrum of the active calcium phosphate material is shown below. Figure 3 As shown, from Figure 3 The characteristic peaks in the middle indicate that the α-TCP crystal phase was successfully formed, with a peak length of only 3448.34 cm⁻¹. -1The presence of a weak water adsorption peak indicates that the additive has achieved efficient dehydroxylation of hydroxyapatite, with no obvious carbon residue or heavy metal compound characteristic peaks.

[0072] This embodiment also provides transistor-compatible ceramics, the preparation method of which is as follows: According to the mass fraction of raw materials, 8% of the above-prepared active calcium phosphate product, 91.5% alumina, and 0.5% sintering aid are mixed, molded at 18 MPa, and sintered at 1300 ℃ for 4 hours to obtain the transistor-compatible ceramic substrate. Here, 8% mass fraction refers to the mass percentage of active calcium phosphate in the total mass of active calcium phosphate and alumina ceramic raw materials.

[0073] The wear resistance, high temperature resistance, insulation, low radiation, and low magnetic properties of the electronic ceramics prepared in this embodiment were tested. The test methods and results are as follows: The wear resistance test method is as follows: A pin-disc wear tester is used. The prepared electronic ceramic sample is fixed on a turntable, and an Al2O3 ceramic pin (hardness HRA 92) is selected as the wear counter. A friction and wear test is conducted under the conditions of a load of 5 N, a rotation speed of 300 r / min, and a wear time of 60 min. The sample mass is weighed before and after the test using an electronic balance with an accuracy of 0.001 mg, and the difference in mass loss is calculated as the wear amount. The wear amount of the electronic ceramic prepared in this embodiment is 0.8 mg.

[0074] The high-temperature resistance test method was as follows: the electronic ceramic sample was placed in a box furnace and heated to 1350 ℃ at a rate of 5 ℃ / min, statically aged at a constant temperature for 2 h, and then naturally cooled to room temperature. The sample surface and interior were then observed using a stereomicroscope (50x magnification) to check for defects such as cracking, deformation, and pulverization. The test results showed that the electronic ceramic prepared in this embodiment did not crack after static aging at 1350 ℃.

[0075] The insulation test method is as follows: The electronic ceramic sample is processed into a Φ20 mm × 5 mm disc, and a high resistance meter (measuring range 10) is used. 6 ~10 18 Under conditions of 25°C and 50% relative humidity, the sample was clamped between two electrodes, a 1000 V DC voltage was applied, and the volume resistivity was read after stabilizing for 1 minute. The test results show that the volume resistivity of the electronic ceramic in this embodiment is 1.5 × 10⁻⁶ Ω. 14 Ω cm.

[0076] The low radiation test method is as follows: a portable gamma radiation dose rate meter (measurement range 0.01~100 μSv / h, accuracy ±5%) is used. The electronic ceramic sample is placed in an environment without background radiation, the instrument probe is 5 cm away from the sample surface, and three consecutive measurements are taken. The average value is taken as the final radiation dose.

[0077] The permeability test method is as follows: using an impedance analyzer, the relative permeability of the electronic ceramic sample is measured under the conditions of a test frequency of 1 MHz and a magnetic field strength of 10 A / m.

[0078] The results show that the radiation of the electronic ceramic in this embodiment is 0.08 μSv / h and the permeability is 1.03, which meets the requirements of transistor signal transmission and can be used as a matching ceramic for transistors.

[0079] Example 2 The preparation of the auxiliary agent for the preparation of active calcium phosphate in this embodiment is the same as in the previous embodiment.

[0080] The preparation of active calcium phosphate is basically the same as in Example 1, except for step (3). In this example, the high-pressure spraying process is omitted. Step (3) is as follows: The calcined product from step (2) was subjected to ultrafine grinding, with the grinding fineness controlled at 300-500 mesh. The product was then sieved using a vibrating sieve with a 50 μm pore size to obtain the active calcium phosphate product. The preparation of electronic ceramics is basically the same as in Example 1, except that the active calcium phosphate used in this example is used.

[0081] Measurements of the active phosphate obtained in this example show that the α-TCP content in the active calcium phosphate obtained in this example is 92.3%, and the volume resistivity is 1.2 × 10⁻⁶. 14 Ω cm, impurity content 0.008%.

[0082] Comparing Examples 1 and 2, it can be seen that, compared to Example 2 which did not employ high-pressure spray adjustment, Example 1 improved the performance of the prepared active calcium phosphate through the high-pressure spray step: on the one hand, the alkali metal carbonates in the spray-applied additives can slowly react with the unreacted Ca in the calcined material. 2+ PO4 3-Contact further promotes ion diffusion, supplements the directional generation of α-TCP, and reduces the residue of impurities such as hydroxyapatite and β-TCP. On the other hand, the water film formed by the polysaccharide derivative can effectively inhibit the agglomeration of material particles, avoid local crystal phase transformation caused by particle agglomeration during grinding, and make the particle size distribution of the ground product more uniform (the span can be reduced from 0.85-0.95 to 0.7-0.8). According to the test, compared with Example 2, the α-TCP content of the active calcium phosphate prepared by Example 1 increased from 92.3% to 94.7%, and the product dispersibility was improved by 31.1%, which is more suitable for the microscopic uniformity requirements of subsequent electronic ceramic raw material mixing, laying the foundation for the stable improvement of the wear resistance, insulation and other properties of electronic ceramics. The wear resistance test of the electronic ceramic obtained in this embodiment showed that its wear amount was 1.1 mg, and it did not crack after static aging at 1250 ℃. The volume resistivity was 1.3 × 10⁻⁶. 14 Ω The ceramic material has a permeability of 1.04 cm, an emissivity of 0.09 μSv / h, and meets the requirements for transistor signal transmission, making it suitable as a supporting ceramic for transistors.

[0083] Example 3 The preparation methods for active calcium phosphate additives include: Weigh the following components by mass: 25 parts of low molecular weight humic acid (approximately 1500 Da), 25 parts of sodium alginate, 45 parts of sodium silicate (modulus 2.2), and 5 parts of potassium carbonate. Place all raw materials in a twin-screw mixer and mix at 180 r / min for 12 minutes. Then, pulverize the mixture to 200 mesh to obtain powdered additives.

[0084] The above-mentioned additives are used to prepare active calcium phosphate, and the preparation method is as follows: Phosphorus-containing battery waste was prepared and pretreated to obtain a phosphorus content of 25%, a calcium content of 32.8%, a total heavy metal content of 85 mg / kg, and a Cu content of [missing information]. 2+ 35 mg / kg, Zn 2+ : 42 mg / kg of phosphorus-containing battery waste raw materials; (1) Add the above powdered additive at 1.5% of the total mass of phosphorus-containing battery waste raw materials and mix at 300 r / min for 15 minutes; (2) Heat to 1150 °C at 10 °C / min, hold for 2.5 hours, and then cool down at 15 °C / min to obtain the calcined product; (3) Take the same powdered additive as above at 0.2% of the total mass of phosphorus-containing sludge raw material and prepare an 8% mass concentration aqueous solution of the additive. Spray the aqueous solution of the additive evenly onto the surface of the calcined material through a high-pressure spraying device. The spraying pressure is 0.9 MPa and the nozzle diameter is 0.5 mm. After spraying, let it stand for 8 minutes to allow the aqueous solution of the additive to fully penetrate into the pores of the material and form a uniform adhesion layer. Then, perform ultra-fine grinding, control the grinding fineness to 500 mesh, and use a vibrating screen with a 50 μm aperture to sieve to obtain the active calcium phosphate product.

[0085] The active calcium phosphate obtained in this example has the following characteristics: α-TCP content 94.1%, upper limit of high temperature resistance 1400 ℃, and heavy metal leaching rate Cu. 2+ 0.05 mg / L, Zn 2+ : 0.04 mg / L.

[0086] The upper limit of high temperature resistance is determined by GB / T 39682-2020 "Determination of Elastic Modulus of Fine Ceramics at High and Ultra-High Temperatures - Notched Ring Relative Method"; the leaching rate of heavy metals is determined according to GB 5085.3-2007 "Identification Standard for Hazardous Waste - Leaching Toxicity Identification".

[0087] This embodiment also provides a ceramic sealing connector for new energy vehicle batteries, the preparation method of which is as follows: According to the mass fraction of raw materials, 12% of the above-prepared active calcium phosphate, 87.5% aluminum nitride, and 0.5% sintering aid are mixed, formed at 20 MPa, and sintered at 1400 ℃ for 5 hours to obtain the ceramic component of the sealing connector for new energy vehicle batteries.

[0088] The corrosion resistance, wear resistance, high temperature resistance, and auxiliary safety of the electronic ceramics prepared in this embodiment were tested, and the test results are as follows: Corrosion resistance tests showed that the mass loss rate was 0.3% after immersion in 5% sulfuric acid for 24 hours, and the wear amount was 0.6 mg. After short-term heating at 1400 ℃ (30 min), the structure remained intact and without deformation. After being combined with the battery separator, the thermal runaway trigger time was extended by 2-3 minutes compared with the group without the addition, thus improving safety redundancy.

[0089] The results above show that the electronic ceramics of this embodiment can be used in the ceramics of sealing connectors for new energy vehicle batteries.

[0090] Example 4 The preparation method of the active calcium phosphate adjuvant includes: Weigh the following components by mass: 40 parts sodium gluconate, 15 parts hydroxypropyl starch (degree of substitution 0.1), 35 parts sodium silicate (modulus 2.8), and 10 parts sodium carbonate. Place all raw materials in a twin-screw mixer and mix at 180 r / min for 12 minutes. Then, pulverize the mixture to 300 mesh to obtain powdered additives.

[0091] The above-mentioned additives are used to prepare active calcium phosphate, and the preparation method is as follows: Phosphorus-containing wastewater was prepared and pretreated to obtain a phosphorus content of 12%, a calcium content of 10.5%, a total heavy metal content of 30 mg / kg, and a Cr content of [missing value]. 3+ : 12 mg / kg of phosphorus-containing waste liquid dried raw material; (1) Add the above powdered additive at 0.6% of the total mass of the dried phosphorus-containing waste liquid raw material, and mix at 200 r / min for 20 minutes; (2) Heat to 950℃ at 5℃ / min, hold for 4 hours, and then cool down at 8℃ / min; (3) Take the same powdered additive as above at 0.25% of the total mass of phosphorus-containing sludge raw material and prepare an additive aqueous solution with a mass concentration of 9%. Spray the additive aqueous solution evenly onto the surface of the calcined material through a high-pressure spraying device. The spraying pressure is 0.85 MPa and the nozzle diameter is 0.5 mm. After spraying, let it stand for 5 minutes to allow the additive aqueous solution to fully penetrate into the pores of the material and form a uniform adhesion layer. Then, perform ultra-fine grinding, control the grinding fineness to 300 mesh, and use a vibrating screen with a 50 μm aperture to sieve to obtain the active calcium phosphate product.

[0092] The active calcium phosphate obtained in this example has the following characteristics: α-TCP content 90.5%, dispersion span 0.82, and radiation dose 0.07 μSv / h. The dispersion span was tested according to the standard "Particle Size Analysis by Laser Diffraction" (GB / T 19077-2016); the radiation dose was tested according to the standard "Basic Standards for Ionizing Radiation Protection and Radiation Source Safety" (GB 18871-2002).

[0093] According to the mass fraction of raw materials, 5% of the above-mentioned active calcium phosphate, 94.5% of alumina and 0.5% of sintering aid are mixed, and after molding at 15MPa, they are sintered at 1200 ℃ for 3 hours to obtain ceramic switch parts for household appliances.

[0094] The insulation, low magnetism, and temperature resistance of the electronic ceramic prepared in this embodiment were tested using the same methods as in Example 1. The test results are as follows: the volume resistivity of the electronic ceramic is 1.1 × 10⁻⁶. 14 Ω The ceramic material has a permeability of 1.02, meeting the insulation requirements for switches; it exhibits no electromagnetic interference; and its performance shows no degradation after aging at 1200 °C, making it suitable for the long-term use environment of household appliances. Therefore, the described electronic ceramic can be used as electronic ceramic for household appliances.

[0095] Example 5 The efficacy of preparing activated calcium phosphate and solidifying heavy metals from phosphorus-containing solid waste with high heavy metal content was verified as follows: The preparation method of the active calcium phosphate adjuvant includes: Weigh the following components by mass: 35 parts sodium citrate, 18 parts sodium alginate, 37 parts sodium silicate (modulus 2.5), and 10 parts potassium carbonate. Place all raw materials in a twin-screw mixer and mix at 180 r / min for 12 minutes. Then, pulverize the mixture to 250 mesh to obtain the powdered additive.

[0096] The above-mentioned additives are used to prepare active calcium phosphate, which is prepared as follows: High-phosphorus-containing solid waste containing heavy metals was prepared and pretreated to obtain a high-phosphorus-containing solid waste raw material with a phosphorus content of 16%, a calcium content of 22.3%, and total heavy metals of: Hg 0.015 mg / kg, As 10.8 mg / kg, Pb 39.2 mg / kg, Cd 0.8 mg / kg, Ni 608 mg / kg, and Cr 266 mg / kg. (1) Add powdered additives at 1.8% of the total mass of the above raw materials and mix at 280 r / min for 18 minutes.

[0097] (2) Heat to 1100 ℃ at 9 ℃ / min, hold for 3 hours, and then cool down at 14 ℃ / min to obtain the calcined product.

[0098] (3) Take the same powdered additive as above at 0.25% of the total mass of phosphorus-containing sludge raw material and prepare an additive aqueous solution with a mass concentration of 9%. Spray the additive aqueous solution evenly onto the surface of the calcined material through a high-pressure spraying device. The spraying pressure is 0.8 MPa and the nozzle diameter is 0.4-0.6 mm. After spraying, let it stand for 7 minutes to allow the additive aqueous solution to fully penetrate into the pores of the material and form a uniform adhesion layer. Then, perform ultra-fine grinding, control the grinding fineness to 400 mesh, and use a vibrating screen with a pore size of 38-53 μm to sieve and obtain a gray-white solid active calcium phosphate product.

[0099] Heavy metal curing effect test: Jiangsu Kangda Testing Technology Co., Ltd. was commissioned to conduct heavy metal total content and leaching toxicity tests on the raw materials and the obtained active calcium phosphate product in this embodiment (test report number: KDWT256887). The test results are shown in Table 1 below.

[0100] Table 1. Test on the heavy metal solidification effect in activated calcium phosphate products.

[0101] As shown in Table 1, even when the total amount of heavy metals such as nickel and chromium in the raw materials is at a high level (Ni 608 mg / kg, Cr 266 mg / kg), after treatment with the additives and processes of this invention, the leaching concentration of heavy metals is not detected or is far below the environmental protection standards. This proves that the dual mechanism of "coordination pre-fixation-vitrification encapsulation" of this additive also has an excellent solidification effect on phosphorus-containing solid waste with high heavy metal content. The safety of the product meets the environmental protection requirements of high-end application scenarios such as electronic ceramics.

[0102] Comparative Example 1 An electronic ceramic is provided, the preparation of which is basically the same as that in Example 1, except that its raw materials only contain alumina ceramic raw materials and do not contain the prepared active calcium phosphate material.

[0103] The wear resistance test of the electronic ceramic showed that its wear amount was 1.3 mg, which is 38.5% higher than that of Example 1. This indicates that the addition of the active calcium phosphate product in Example 1 improved the wear resistance of the electronic ceramic. The high-temperature resistance test showed that the electronic ceramic of this comparative example developed microcracks at 1200 °C, a 12.5% ​​decrease in high-temperature resistance compared to Example 1. The volume resistivity test showed that the volume resistivity of the electronic ceramic of this comparative example was 8 × 10⁻⁶. 13 Ω cm.

[0104] Comparative Example 2 An electronic ceramic is provided, the preparation of which is basically the same as that of Example 3, except that its raw materials do not include the active calcium phosphate product prepared in Example 3.

[0105] Tests on the corrosion resistance and wear resistance of the electronic ceramics showed that the mass loss rate after immersion in 5% sulfuric acid for 24 hours was 0.8%, which was 62.5% higher than that of Example 3; the wear amount was 1.0 mg, which was 40% higher than that of Example 3.

[0106] The bio-based composite activator of this invention can efficiently convert phosphorus-containing solid waste into high-performance active calcium phosphate. This active calcium phosphate not only overcomes the performance limitations of traditional active calcium phosphate but also serves as a raw material for electronic ceramics, achieving multi-dimensional performance upgrades and adapting to high-end applications such as transistors and ceramic components for new energy vehicle batteries. Its green and environmentally friendly characteristics, low cost, and controllable performance combine economic value and environmental benefits, making it widely applicable in the fields of high-value utilization of recycled resources and upgrading the electronic ceramics industry. Further optimization of the additive ratio and experimental parameters can refine the specific performance data for electronic ceramics applications, enhancing the industrial applicability of the technology. Simultaneously, the efficient treatment capability of this invention for phosphorus-containing solid waste with high heavy metal content provides a new path for the resource utilization of polluted solid waste, possessing both environmental value and industrial promotion potential.

[0107] The above description is merely a preferred embodiment of the present invention, and the present invention is not limited to the above embodiments. It is understood that other improvements and variations that are directly derived or conceived by those skilled in the art without departing from the spirit and concept of the present invention should be considered to be included within the protection scope of the present invention.

Claims

1. A bio-based composite active adjuvant, characterized in that, The bio-based composite active additive comprises the following raw material components in parts by weight: 20-40 parts of bio-based organic acid or bio-based organic acid salt, 15-30 parts of polysaccharide or its derivative, 25-45 parts of alkali metal silicate, and 5-15 parts of alkali metal carbonate.

2. The bio-based composite active agent according to claim 1, characterized in that, The bio-based organic acid includes at least one of the following: citric acid, gluconic acid, and low molecular weight humic acid. Preferably, the molecular weight of the low molecular weight component of the humic acid is 500~3000 Da, and the molar ratio of carboxyl groups to phenolic hydroxyl groups is 2:1~3:1; The bio-based organic acid salts include at least one of citrate and gluconate.

3. The bio-based composite active agent according to claim 1, characterized in that, The polysaccharide or its derivatives include at least one of sodium carboxymethyl cellulose, sodium alginate, and modified starch; Preferably, the modified starch includes at least one of hydroxypropyl starch and acetate starch.

4. The bio-based composite active agent according to claim 1, characterized in that, The alkali metal silicate includes sodium silicate; Preferably, the modulus of the sodium silicate is 2 to 3, and / or, At 20℃, the viscosity of a 5% sodium silicate aqueous solution is 20~50 mPa·s; The alkali metal carbonate is at least one of sodium carbonate and potassium carbonate.

5. A method for preparing the bio-based composite active adjuvant according to any one of claims 1-4, characterized in that, Includes the following steps: The bio-based organic acid or bio-based organic acid salt, the polysaccharide or polysaccharide derivative, the alkali metal silicate, and the alkali metal carbonate in the specified amounts are placed in a double helix mixing device, mixed, and then pulverized to obtain the final product. Preferably, the mixing speed is 150~200 r / min and the mixing time is 10~15 min; The particle size of the bio-based composite active agent is 200-300 mesh.

6. A method for producing activated calcium phosphate from phosphorus-containing waste, characterized in that, Including the following methods: S1: Mix the phosphorus-containing waste with a bio-based composite active agent to obtain a premix; S2: Calcine the premixed material to obtain the calcined product; S3: Grind and sieve the calcined product to obtain active calcium phosphate.

7. The method according to claim 6, characterized in that, In step S1, the phosphorus-containing waste includes at least one of phosphorus-containing waste liquid, phosphorus-containing sludge, and phosphorus-containing battery waste. The bio-based composite active agent is the bio-based composite active agent according to any one of claims 1-4, or the bio-based composite active agent prepared by the preparation method according to claim 5; The amount of the bio-based composite active additive added is 0.5-2.0% of the weight of the phosphorus-containing waste material; The mixing speed is 200~300 r / min, and the time is 15~20 min; In step S2, the calcination temperature is 900~1200℃ and the time is 2~4 h; In step S3, the particle size of the active calcium phosphate is 38~53μm.

8. The method according to any one of claims 6-7, characterized in that, Before grinding in step S3, the following steps are also included: Take 0.1-0.3% of the bio-based composite active agent by mass from the phosphorus-containing waste, add water and mix to obtain an aqueous solution of the bio-based composite active agent with a mass concentration of 5-10%. A 5-10% (w / w) aqueous solution of bio-based composite active additives was applied by high-pressure spraying to the surface of the calcined product obtained in step S2, and allowed to stand for 5-10 minutes. Preferably, the pressure of the high-pressure spray is 0.6~1.0MPa and the nozzle diameter is 0.4~0.6mm.

9. An active calcium phosphate prepared by the method according to any one of claims 7-8, characterized in that, In the active calcium phosphate, the mass percentage of α-tricalcium phosphate is ≥90%; the impurity content is ≤0.01%; and / or, The volume resistivity of the active calcium phosphate is ≥1×10⁻⁶. 14 Ω cm.

10. An electronic ceramic, characterized in that, The electronic ceramics include activated calcium phosphate; The active calcium phosphate in the electronic ceramic has a mass fraction of 5-15%; The active calcium phosphate is the active calcium phosphate according to claim 9, or the active calcium phosphate prepared by the preparation method according to any one of claims 7-8.

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