A method for preparing a highly dispersible composite filler

Abstract

This application relates to a method for preparing a highly dispersible composite filler. The method includes: mixing steel slag powder, granulated blast furnace slag powder, and carbonaceous secondary resources to obtain a raw material mixture; ultra-fine grinding the raw material mixture to obtain ultra-fine powder; synergistically classifying the ultra-fine powder to separate fine powder of a target particle size; adjusting the classification airflow to match the classification airflow with the production capacity of the ultra-fine grinding; compounding and modifying the fine powder to form a modified filler; the compounding and modification uses a compound modifier, which includes a combination of silane coupling agent, titanate coupling agent, and polyethylene glycol, or a combination of titanate coupling agent and calcium stearate; homogenizing and packaging the modified filler to obtain a composite filler. The resulting composite filler achieves high-value utilization of solid waste resources and reduces production energy consumption and overall costs, providing an innovative solution for replacing traditional high-end fillers.

Description

Technical Field

[0001] This application relates to the field of new materials technology, and in particular to a method for preparing a highly dispersible composite filler. Background Technology

[0002] The steel industry is a pillar industry of the national economy, but the large amount of metallurgical solid waste such as steel slag generated each year leads to problems such as land accumulation and environmental pollution due to low comprehensive utilization rates. The chemical composition of this type of metallurgical solid waste is similar to that of cement clinker, theoretically possessing the potential to become a high-end filler. However, limited by the inherent properties of the material, steel slag is currently mainly used in low-value-added fields.

[0003] Existing technologies for preparing high-end fillers from steel slag face multiple challenges: 1) Insufficient powder performance: The prepared powders are difficult to meet the stringent requirements of high-end coatings and precision rubber products in terms of particle size and distribution; 2) Low efficiency of modification processes: The surface modification process is inefficient, resulting in insufficient dispersion of the filler in the organic matrix and limited improvement in the key performance of the products; 3) High production costs: Traditional production processes are energy-intensive, and complex modification schemes further increase the overall cost; 4) Poor application adaptability: Existing technologies are difficult to meet the needs of multiple application scenarios and cannot adapt to the goal of low-carbon production in the industry.

[0004] Despite existing patented technologies, including compound grinding and single-component modification, the performance of composite fillers remains largely limited to low-end applications. For example, the preparation process of ultrafine powders often suffers from bottlenecks such as insufficient synergy between grinding and classification, and limited precision in surface modification, resulting in the inability to precisely control powder properties. While high-temperature activation or composite modification may improve some indicators, they often significantly increase energy consumption and costs, contradicting the green manufacturing orientation. These factors collectively indicate that existing technological approaches have not yet systematically overcome the core bottlenecks in the high-value utilization of metallurgical solid waste. Summary of the Invention

[0005] This application provides a method for preparing highly dispersible composite fillers to solve the following technical problem: how to achieve high-value composite fillers.

[0006] This application provides a method for preparing a highly dispersible composite filler, the method comprising: Steel slag powder, granulated blast furnace slag powder and carbon-containing secondary resources are batched to obtain a raw material mixture; The raw material mixture is subjected to ultrafine grinding to obtain ultrafine powder; the ultrafine grinding adopts a grinding method with a grading liner, and the steel ball gradation of the grinding method is Φ10mm:Φ15mm:Φ20mm=3:5:2; The ultrafine powder is synergistically classified to separate fine powder of the target particle size; the synergistic classification is achieved by adjusting the classification air volume to match the production capacity of the ultrafine powder mill. The fine powder is compounded and modified to form a modified filler; the compounding modification uses a compounding modifier, which includes a combination of silane coupling agent, titanate coupling agent and polyethylene glycol, or a combination of titanate coupling agent and calcium stearate. The modified filler was homogenized and packaged to obtain a composite filler.

[0007] Optionally, in the batching step, the mass fraction of the steel slag powder is 60%~75%, the mass fraction of the granulated blast furnace slag powder is 20%~35%, and the mass fraction of the carbon-containing secondary resources is 3%~5%; or, The mass fraction of the carbon-containing secondary resources is 90%~98%, the mass fraction of the steel slag powder is 1%~5%, and the mass fraction of the granulated blast furnace slag powder is 1%~5%.

[0008] Optionally, in the batching step, the steel slag powder, the granulated blast furnace slag powder, and the carbon-containing secondary resources all meet the following requirements: mesh size ≥ 400 mesh, D90 ≤ 35 μm, and moisture content ≤ 0.8%.

[0009] Optionally, in the ultrafine grinding step, the feed rate of the grinding method is 1.2t / h~1.5t / h, the grinding time is 1.5h~2.0h, inert gas is introduced during the grinding process, and the grinding current is adjusted in real time to 150A~160A through online particle size monitoring to ensure that the D90 of the ultrafine powder is ≤15μm.

[0010] Optionally, in the collaborative grading step, the grading air volume is 4000 m³ / h. 3 / h~4500m 3 / h, the first-stage classification removes coarse powder with D90≥20μm and returns it to the ultrafine grinding step for re-grinding, the second-stage classification controls the fine powder D90≤12μm, and the product yield is 90%~95%.

[0011] Optionally, in the compound modification step, the compound modifier includes a combination of silane coupling agent KH-550, titanate coupling agent NDZ-311 and polyethylene glycol PEG-400. The mass fraction of the silane coupling agent KH-550 is 0.2%~0.5%, the mass fraction of the titanate coupling agent NDZ-311 is 0.1%~0.3%, and the mass fraction of the polyethylene glycol PEG-400 is 0.1%~0.2%.

[0012] Optionally, the compound modifier includes a combination of titanate coupling agent NDZ-201 and calcium stearate, wherein the mass fraction of titanate coupling agent NDZ-201 is 0.3%~0.6% and the mass fraction of calcium stearate is 0.2%~0.4%.

[0013] Optionally, in the compound modification step, the mixing temperature is 60℃~70℃, the mixing time is 8min~12min, and the modifier coating rate is ≥92%.

[0014] Optionally, a raw material pretreatment step may be included before the ingredient preparation step; The raw material pretreatment includes: removing iron from the steel slag powder by magnetic separation to an iron content ≤0.5%; removing impurities from the granulated blast furnace slag powder by air separation to an impurity content ≤0.3%; and drying the carbon-containing secondary resources to a moisture content ≤0.8%.

[0015] Optionally, the composite filler product has a D90 ≤ 15μm, a 45μm sieve residue ≤ 0.08%, an oil absorption value ≤ 55g / 100g, and a bulk density ≤ 2.3g / cm³. 3 Contact angle ≥35°, moisture content ≤0.8%.

[0016] Optionally, in the homogenization and packaging step, the modified powder is homogenized after being cooled to room temperature, with batch-to-batch performance fluctuations ≤3% and packaging accuracy ±0.2%.

[0017] Optionally, the coordinated classification step may further include a pulse dust collection step, with the exhaust dust concentration ≤8mg / m³. 3 .

[0018] The technical solutions provided in this application have the following advantages compared with the prior art: This application provides a method for preparing a highly dispersible composite filler. The method includes: mixing steel slag powder, granulated blast furnace slag powder, and carbonaceous secondary resources to obtain a raw material mixture; subjecting the raw material mixture to ultrafine grinding to obtain ultrafine powder; the ultrafine grinding adopts a grinding method with a classifying liner, wherein the steel ball gradation of the grinding method is Φ10mm:Φ15mm:Φ20mm=3:5:2; performing synergistic classification on the ultrafine powder to separate fine powder of the target particle size; the synergistic classification is achieved by adjusting the classifying air volume to match the capacity of the ultrafine grinding; the fine powder is compounded and modified to form a modified filler; the compounding modification uses a compound modifier, which includes a combination of silane coupling agent, titanate coupling agent and polyethylene glycol, or a combination of titanate coupling agent and calcium stearate; and homogenizing and packaging the modified filler to obtain a composite filler. By establishing a specific phase foundation through specific ingredient formulation, the rigidity of steel slag, the activity of mineral slag, and the conductivity of carbon-containing resources complement each other. Then, a grinding method using graded liners and specifically graded steel balls is employed to promote particle spheroidization while efficiently crushing, controlling particle size distribution and morphology from the source. Essentially, this activates the particle surface through mechanochemical effects, creating active sites for subsequent modification. The synergistic grading step achieves highly selective separation of fine powders of the target particle size through dynamic matching of airflow and grinding capacity, ensuring ideal initial dispersion of the powder, resulting in a steep particle size distribution curve, reducing excessively coarse and fine particles, and achieving the densest packing in the composite filler. Subsequent compounding and modification steps select combinations of silane coupling agents, titanate coupling agents, and polyethylene glycol based on the final application scenario to optimize compatibility with the organic polymer matrix, or select combinations of titanate coupling agents and calcium stearate to enhance dispersion and reinforcement in rubber, thereby directionally imparting surface functions to the composite filler. Finally, homogenized packaging ensures batch stability of the composite filler product performance, fully realizing the value leap from solid waste to high-performance composite filler.

[0019] In summary, by precisely matching raw materials, parametrically coupling grinding and grading processes, and employing application-oriented compound surface modification strategies, the core technological bottlenecks of metallurgical solid waste—characterized by large compositional fluctuations, surface inertness, and easy agglomeration—have been systematically overcome, resulting in low performance and narrow applications. Based on this, the waste is transformed into a high-value-added composite material with controllable particle size, excellent dispersibility, and specific interfacial functions, thereby achieving a fundamental value enhancement from low-end waste to high-performance filler. Attached Figure Description

[0020] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0021] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, those skilled in the art can obtain other drawings based on these drawings without any creative effort.

[0022] Figure 1 This is a flowchart illustrating a method for preparing a highly dispersible composite filler, as provided in an embodiment of this application. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below. Obviously, the described embodiments are only some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0024] The range descriptions used herein, such as numerical ranges and proportional ranges, include all possible sub-ranges and single numerical values ​​within that range. For example, the range descriptions of "1 to 6" or "1~6" cover all sub-ranges between 1 and 6 (such as 1 to 3, 2 to 5, etc.) and single numbers (such as 1, 2, 3, 4, 5, 6). Unless otherwise specified, the terms "including" and "contains" used herein mean "including but not limited to"; relational terms such as "first" and "second" are used only to distinguish different entities or operations and do not imply an actual order or relationship. "And / or" indicates that multiple situations can exist individually or simultaneously. Expressions such as "at least one," "multiple," and "at least one" refer to any combination of the corresponding objects, including combinations of single or multiple objects. The proportional relationships mentioned herein, such as mass ratios and molar ratios, should be understood as the correspondence between the first and second terms of a proportional formula, according to the order of description. The raw materials, reagents, instruments, and equipment used herein can all be obtained through commercial purchase or prepared using existing methods.

[0025] Figure 1 This is a flowchart illustrating a method for preparing a highly dispersible composite filler, as provided in an embodiment of this application.

[0026] Please see Figure 1 This application provides a method for preparing a highly dispersible composite filler, the method comprising: S1. Steel slag powder, granulated blast furnace slag powder and carbon-containing secondary resources are batched to obtain a raw material mixture; S2. The raw material mixture is subjected to ultrafine grinding to obtain ultrafine powder; the ultrafine grinding adopts a grinding method with a grading liner, and the steel ball gradation of the grinding method is Φ10mm:Φ15mm:Φ20mm=3:5:2; S3. The ultrafine powder is subjected to synergistic classification to separate fine powder of the target particle size; the synergistic classification is achieved by adjusting the classification air volume to match the capacity of the ultrafine powder mill. S4. The fine powder is compounded and modified to form a modified filler; the compounding modification uses a compounding modifier, which includes a combination of silane coupling agent, titanate coupling agent and polyethylene glycol, or a combination of titanate coupling agent and calcium stearate. S5. The modified filler is homogenized and packaged to obtain a composite filler.

[0027] In the above technical solution, precise ingredient proportioning lays the foundation for the synergistic phase composition of multiple components; then, a specific steel ball gradation grinding method is adopted, and the material is ultra-finely pulverized and its morphology optimized with the help of a classifying liner; subsequently, by dynamically matching the classifying air volume and grinding capacity, fine powder within the target particle size range is efficiently separated; then, according to the final application scenario, a compound modifier is selected to perform surface functionalization modification on the fine powder, constructing a stable organic-inorganic interface; finally, homogenization and packaging ensure the batch stability of product performance.

[0028] In some embodiments, during the batching step, the steel slag powder has a mass fraction of 60%~75%, the granulated blast furnace slag powder has a mass fraction of 20%~35%, and the carbon-containing secondary resources have a mass fraction of 3%~5%; or, The mass fraction of the carbon-containing secondary resources is 90%~98%, the mass fraction of the steel slag powder is 1%~5%, and the mass fraction of the granulated blast furnace slag powder is 1%~5%.

[0029] The first formulation is dominated by steel slag powder, which has a high mass fraction and provides the main rigid framework and chemical activity, ensuring the composite filler has good basic strength and reaction interface. Granulated blast furnace slag powder serves as an important supplement of silica and alumina, optimizing the overall particle size distribution and long-term stability. A small amount of carbon-containing secondary resources mainly plays an auxiliary functional adjustment role. For example, the mass fraction of steel slag powder can be 60%, 65%, 70%, 75%, etc.; the mass fraction of granulated blast furnace slag powder can be 20%, 25%, 30%, 35%, etc.; and the mass fraction of carbon-containing secondary resources can be 3%, 4%, 5%, etc.

[0030] The second formulation uses carbon-containing secondary resources as the absolute main component, aiming to maximize the unique functional characteristics of these resources. The introduction of very small amounts of steel slag powder and granulated blast furnace slag powder is primarily for fine-tuning, slightly increasing hardness or controlling costs. For example, the mass fraction of carbon-containing secondary resources can be 90%, 92%, 94%, 96%, 98%, etc. for steel slag powder; 1%, 2%, 3%, 4%, 5%, etc. for steel slag powder; and 1%, 2%, 3%, 4%, 5%, etc. for granulated blast furnace slag powder.

[0031] In some embodiments, during the batching step, the steel slag powder, the granulated blast furnace slag powder, and the carbon-containing secondary resources all meet the following requirements: mesh size ≥ 400 mesh, D90 ≤ 35 μm, and moisture content ≤ 0.8%.

[0032] Steel slag powder, granulated blast furnace slag powder, and carbon-containing secondary resources all meet the following requirements: mesh size ≥ 400 mesh, D90 ≤ 35 μm, and moisture content ≤ 0.8%. This ensures the uniformity of particle size when the materials enter the ultrafine mill, thereby improving grinding efficiency and reducing energy consumption. The extremely low moisture content effectively inhibits the tendency of powder to agglomerate during processing and creates a dry and stable interface environment for the subsequent full and uniform reaction between the compound modifier and the particle surface, ultimately ensuring the high dispersibility and stable coating effect of the resulting composite filler. For example, the mesh size can be 400 mesh, 500 mesh, 600 mesh, etc.; D90 can be 31 μm, 33 μm, 35 μm, etc.; and the moisture content can be 0.5%, 0.6%, 0.7%, 0.8%, etc.

[0033] In some embodiments, in the ultrafine grinding step, the feed rate of the grinding method is 1.2t / h to 1.5t / h, the grinding time is 1.5h to 2.0h, inert gas is introduced during the grinding process, and the grinding current is adjusted in real time to 150A to 160A through online particle size monitoring to ensure that the D90 of the ultrafine powder is ≤15μm.

[0034] The feed rate for grinding is between 1.2 t / h and 1.5 t / h. This avoids both equipment overload leading to decreased grinding efficiency and insufficient feed causing energy waste, maintaining the continuous and stable operation of the ultrafine ball mill during grinding. For example, the feed rate can be 1.2 t / h, 1.3 t / h, 1.4 t / h, 1.5 t / h, etc. The grinding time is between 1.5 h and 2.0 h, ensuring that the raw material mixture is fully crushed to achieve the target fineness while minimizing powder agglomeration and abnormal energy consumption caused by over-grinding. For example, the grinding time can be 1.5 h, 1.6 h, 1.7 h, 1.8 h, 1.9 h, 2.0 h, etc. An inert gas (N2) is introduced during the grinding process to prevent oxidation of carbonaceous secondary resources. Real-time online particle size monitoring and adjustment of the grinding current between 150A and 160A are used to dynamically balance the kinetic energy of the grinding media and the crushing intensity of the material, thereby effectively suppressing over-grinding and ensuring the stability of the powder particle size distribution. This provides powder raw materials that meet the fineness standards for subsequent classification processes. For example, the grinding current can be 150A, 152A, 154A, 156A, 158A, 160A, etc. Ensuring that the D90 of the ultrafine powder is ≤15μm meets the basic performance threshold for the fineness of composite fillers in high-end applications, providing a qualified raw material input standard for subsequent classification processes. For example, the D90 of the ultrafine powder can be 10μm, 11μm, 12μm, 13μm, 14μm, 15μm, etc.

[0035] In some embodiments, the grading air volume in the collaborative grading step is 4000 m³ / h. 3 / h~4500m 3 / h, the first-stage classification removes coarse powder with D90≥20μm and returns it to the ultrafine grinding step for re-grinding, the second-stage classification controls the fine powder D90≤12μm, and the product yield is 90%~95%.

[0036] The air volume is 4000m³ / h. 3 / h~4500m 3 Between / h, through a two-stage synergistic mechanism of primary separation of coarse particles and secondary fine sieving, high-precision particle size classification of powder is achieved in the airflow field, while maintaining stable negative pressure in the system to ensure the yield and uniformity of ultrafine powder particle size distribution. For example, the classification airflow can be 4000m³ / h. 3 / h、4100m 3 / h, 4200m 3 / h、4300m 3 / h, 4400m 3 / h, 4500m 3The primary classification process removes coarse powder particles by sieving them and returning them to the mill for reprocessing, eliminating the interference of excessive particle size components on the quality of the composite filler and ensuring the recycling rate of raw materials. The secondary classification process, combined with a variable frequency fan to dynamically adjust the classification airflow, precisely matches the airflow processing capacity with the ball mill capacity (the airflow increases or decreases synchronously with the feed rate, with fluctuations controlled within ±5%), achieving efficient separation and collection of the target fine powder. Finally, the finished powder with the required particle size is obtained after treatment by a high-precision pulse dust collector. For example, the D90 of the coarse powder removed by the primary classification can be 20μm, 22μm, 24μm, 26μm, 28μm, 30μm, etc.; the D90 of the fine powder controlled by the secondary classification can be 6μm, 8μm, 10μm, 12μm, etc.; the product yield can be 90%, 91%, 92%, 93%, 94%, 95%, etc.

[0037] In some embodiments, the compound modification step includes a combination of silane coupling agent KH-550, titanate coupling agent NDZ-311, and polyethylene glycol PEG-400. The mass fraction of the silane coupling agent KH-550 is 0.2%~0.5%, the mass fraction of the titanate coupling agent NDZ-311 is 0.1%~0.3%, and the mass fraction of the polyethylene glycol PEG-400 is 0.1%~0.2%.

[0038] The amino functional groups in the silane coupling agent KH-550 preferentially anchor to the surface of fine powder particles, forming strong chemical bonds and exposing organic segments. The alkoxy groups in the titanate coupling agent NDZ-311 further reduce the surface energy of the fine powder through a grafting reaction, blocking polar agglomeration. The long-chain molecules of polyethylene glycol PEG-400 utilize steric hindrance to inhibit secondary aggregation of fine powder particles while simultaneously improving their wettability with the organic matrix. These three agents work synergistically to construct an organic-inorganic transition layer on the surface of the fine powder, possessing high reactivity, low interfacial tension, and good dispersion stability. This lays the foundation for the uniform dispersion and performance enhancement of the subsequently formed composite filler in the polymer system. For example, the mass fraction of the silane coupling agent KH-550 can be 0.2%, 0.3%, 0.4%, 0.5%, etc.; the mass fraction of the titanate coupling agent NDZ-311 can be 0.1%, 0.2%, 0.3%, etc.; and the mass fraction of the polyethylene glycol PEG-400 can be 0.1%, 0.2%, etc.

[0039] In some embodiments, the compound modifier comprises a combination of titanate coupling agent NDZ-201 and calcium stearate, wherein the mass fraction of titanate coupling agent NDZ-201 is 0.3% to 0.6% and the mass fraction of calcium stearate is 0.2% to 0.4%.

[0040] The alkoxy groups of the titanate coupling agent NDZ-201 first react chemically with the hydroxyl groups on the surface of the fine powder to form strong chemical bonds and graft hydrophobic long chains, thereby significantly reducing the surface energy of the fine powder and improving its wettability in the organic phase. Simultaneously, calcium stearate molecules further coat the surface of the fine powder particles through physical adsorption and partial chemical reaction, providing excellent dispersing and lubricating effects to reduce processing friction and agglomeration, and also playing a certain activating and stabilizing role in subsequent vulcanization or processing. These two components synergistically construct a modified layer on the surface of the fine powder with strong interfacial bonding, excellent dispersibility, and processing lubrication, thus transforming the fine powder into a modified filler and ultimately significantly improving the mechanical properties, processing flowability, and product uniformity of composite materials (especially rubber products). For example, the mass fraction of the titanate coupling agent NDZ-201 can be 0.3%, 0.4%, 0.5%, 0.6%, etc.; the mass fraction of calcium stearate can be 0.2%, 0.3%, 0.4%, etc.

[0041] In some embodiments, during the compound modification step, the mixing temperature is 60℃~70℃, the mixing time is 8min~12min, and the coating rate of the modifier is ≥92%.

[0042] In the compound modification step, the mixing temperature is 60℃~70℃, and the mixing time is 8min~12min. Thermal energy is used to promote the full spreading, penetration, and chemical bonding of the compound modifier molecules on the powder surface, thereby achieving a uniform interface functionalization with a coating rate ≥92%. Subsequently, cooling treatment eliminates the heat accumulation effect, maintaining the stability of the compound modifier molecular structure and laying the foundation for the high dispersibility of the final composite filler. For example, the mixing temperature can be 60℃, 62℃, 64℃, 66℃, 68℃, 70℃, etc.; the mixing time can be 8min, 9min, 10min, 11min, 12min, etc.; and the modifier coating rate can be 92%, 94%, 96%, etc.

[0043] In some embodiments, a raw material pretreatment step is included before the ingredient mixing step; The raw material pretreatment includes: removing iron from the steel slag powder by magnetic separation to an iron content ≤0.5%; removing impurities from the granulated blast furnace slag powder by air separation to an impurity content ≤0.3%; and drying the carbon-containing secondary resources to a moisture content ≤0.8%.

[0044] In the raw material pretreatment process, steel slag powder is magnetically separated to remove iron to an iron content of ≤0.5% to avoid equipment wear; granulated blast furnace slag powder is air-separated to remove impurities to an impurity content of ≤0.3% to ensure chemical purity; and carbon-containing secondary resources are dried to a moisture content of ≤0.8% to prevent particle agglomeration in subsequent processes. Subsequently, an automatic metering system (accuracy ±0.1%) precisely proportions the above raw materials to create a low-defect, high-stability raw material mixture, thus providing the necessary purity guarantee for subsequent ultrafine processing and surface modification. For example, the iron content of steel slag powder after magnetic separation can be 0.1wt%, 0.2wt%, 0.3wt%, 0.4wt%, 0.5wt%, etc.; the impurity content of granulated blast furnace slag powder after air separation can be 0.1wt%, 0.2wt%, 0.3wt%, etc.; and the moisture content of carbon-containing secondary resources after drying can be 0.2%, 0.4%, 0.6%, 0.8%, etc.

[0045] In some embodiments, the composite filler product has a D90 ≤ 15 μm, a 45 μm sieve residue ≤ 0.08%, an oil absorption value ≤ 55 g / 100 g, and a bulk density ≤ 2.3 g / cm³. 3 Contact angle ≥35°, moisture content ≤0.8%.

[0046] The D90 ≤ 15μm and 45μm sieve residue ≤ 0.08% together ensure that the powder is in an ultrafine state with extremely low coarse particle content. This provides the most basic physical prerequisite for the composite filler to achieve highly uniform dispersion in the matrix and avoid stress concentration points. An oil absorption value ≤ 55g / 100g directly reflects the low demand for resin or plasticizer by the composite filler. This means that the composite filler can maintain good flowability during polymer processing and reduce the negative impact on the system viscosity. Bulk density ≤ 2.3g / cm³ 3 This indicates that the composite filler has a loosely packed particle structure, which is beneficial for faster wetting and more uniform distribution during the mixing process. A contact angle ≥35° is key evidence that the composite filler surface has been effectively modified, changing from hydrophilic to hydrophobic, directly determining the interfacial compatibility and bonding strength between the composite filler and the organic polymer matrix. A moisture content ≤0.8% is an important quality control indicator to ensure the storage stability of the composite filler, prevent agglomeration, and avoid the generation of bubbles during subsequent high-temperature processing or curing, which could affect the final performance of the product. For example, D90 can be 10μm, 11μm, 12μm, 13μm, 14μm, 15μm, etc.; 45μm sieve residue can be 0.02%, 0.04%, 0.06%, 0.08%, etc.; oil absorption value can be 15g / 100g, 25g / 100g, 35g / 100g, 45g / 100g, 55g / 100g, etc.; and bulk density can be 2.0g / cm³. 3 2.1g / cm3 2.2g / cm 3 2.3g / cm 3 Contact angles can be 35°, 40°, 45°, etc.; moisture content can be 0.5%, 0.6%, 0.7%, 0.8%, etc.

[0047] In some embodiments, during the homogenization and packaging step, the modified powder is cooled to room temperature and then homogenized, with batch-to-batch performance fluctuations ≤3% and packaging accuracy ±0.2%.

[0048] The homogenization process involves feeding the modified and cooled powder into a buffer chamber (10m³). 3 The mixture is thoroughly mixed via a homogenizing spiral (15 r / min), effectively eliminating potential differences in composition and performance caused by minor fluctuations in earlier processes, thus ensuring batch-to-batch performance variation ≤3%. The packaging process utilizes an air-floating valve bag packaging machine (packaging accuracy ±0.2%), achieving precise control over the weight of each bag. It also provides standard bags, ton bags, and even bulk storage (60m³). 3 The various forms of direct delivery ensure consistent product quality and accurate measurement, while flexibly adapting to the diverse warehousing, transportation, and usage needs of downstream customers, thus completing the final transformation from qualified products to standardized commodities.

[0049] In some embodiments, the coordinated classification step is followed by a pulse dust collection step, with the exhaust dust concentration ≤8mg / m³. 3 .

[0050] Dust concentration in exhaust ≤8mg / m³ 3 This ensures that the production environment meets environmental regulations, while reducing raw material loss and maintaining the negative pressure stability of the grading system, thus establishing a clean operating benchmark for continuous production. For example, the concentration of emitted dust can be 2 mg / m³. 3 4mg / m 3 6mg / m 3 8mg / m 3 wait.

[0051] The present application is further illustrated below with reference to specific embodiments. Experimental methods in the following embodiments that do not specify specific conditions are generally determined according to national standards / industry standards / the disclosure herein; if there are no corresponding national standards / industry standards / the disclosure herein, they are performed according to generally accepted international standards, conventional conditions, or conditions recommended by the manufacturer.

[0052] Example 1 Application of composite fillers in anti-corrosion coatings; 70 kg of steel slag powder (D90=32μm), 27 kg of granulated blast furnace slag powder (D90=30μm) and 3 kg of carbon-containing secondary resources (D90=28μm) were pretreated and then batched to obtain a raw material mixture; The raw material mixture was subjected to ultrafine grinding at a feed rate of 1.3 t / h for 1.8 h. Inert gas was introduced during the grinding process, and the grinding current was adjusted to 155 A in real time using online particle size monitoring to ensure that the D90 of the ultrafine powder was 13.2 μm and the specific surface area was 850 m². 2 / kg, to obtain ultrafine powder; the ultrafine grinding adopts a grinding method with a classifying liner, and the steel ball gradation of the grinding method is Φ10mm:Φ15mm:Φ20mm=3:5:2; Ultrafine powders are synergistically classified to separate fine powders of the target particle size. This synergistic classification is achieved by adjusting the classification airflow to match the production capacity of the ultrafine powder mill. Specifically, the primary classifier operates at a speed of 260 r / min, the secondary classifier at 280 r / min, and the classification airflow is 4200 m³ / min. 3 / h, the primary classification removes coarse powder with D90≥20μm and returns it to the ultrafine grinding step for re-grinding, and the secondary classification controls the fine powder D90≤12μm, with a product yield of 92%; The fine powder is compounded and modified to form a modified filler; the compounding modification uses a compound modifier, which includes 0.3 kg of silane coupling agent, 0.2 kg of titanate coupling agent and 0.15 kg of polyethylene glycol, the mixing temperature is 65℃ and the mixing time is 10 min; The modified filler was homogenized and packaged to obtain a composite filler.

[0053] Example 2 Application of composite fillers in anti-corrosion coatings; 70 kg of steel slag powder (D90=32μm), 27 kg of granulated blast furnace slag powder (D90=30μm) and 3 kg of carbon-containing secondary resources (D90=28μm) were pretreated and then batched to obtain a raw material mixture; The raw material mixture was subjected to ultrafine grinding at a feed rate of 1.3 t / h for 1.8 h. Inert gas was introduced during the grinding process, and the grinding current was adjusted to 155 A in real time using online particle size monitoring to ensure that the D90 of the ultrafine powder was 13.2 μm and the specific surface area was 850 m². 2 / kg, to obtain ultrafine powder; the ultrafine grinding adopts a grinding method with a classifying liner, and the steel ball gradation of the grinding method is Φ10mm:Φ15mm:Φ20mm=3:5:2; Ultrafine powders are synergistically classified to separate fine powders of the target particle size. This synergistic classification is achieved by adjusting the classification airflow to match the production capacity of the ultrafine powder mill. Specifically, the primary classifier operates at a speed of 260 r / min, the secondary classifier at 280 r / min, and the classification airflow is 4200 m³ / min. 3 / h, the primary classification removes coarse powder with D90≥20μm and returns it to the ultrafine grinding step for re-grinding, and the secondary classification controls the fine powder D90≤12μm, with a product yield of 92%; The fine powder is compounded and modified to form a modified filler; the compound modification uses a compound modifier, which includes 0.3 kg of silane coupling agent and 0.35 kg of titanate coupling agent, the mixing temperature is 65℃ and the mixing time is 10 min; The modified filler was homogenized and packaged to obtain a composite filler.

[0054] Example 3 Application of composite fillers in rubber products; 3 kg of steel slag powder (D90=32μm), 2 kg of granulated blast furnace slag powder (D90=30μm) and 95 kg of carbon-containing secondary resources (D90=29μm) were pretreated and then batched to obtain a raw material mixture; The raw material mixture was subjected to ultrafine grinding at a feed rate of 1.2 t / h for 1.6 h. Inert gas was introduced during the grinding process, and the grinding current was adjusted to 152 A in real time using online particle size monitoring to ensure that the D90 of the ultrafine powder was 12.5 μm and the specific surface area was 880 m². 2 / kg, to obtain ultrafine powder; the ultrafine grinding adopts a grinding method with a classifying liner, and the steel ball gradation of the grinding method is Φ10mm:Φ15mm:Φ20mm=3:5:2; Ultrafine powders are synergistically classified to separate fine powders of the target particle size. This synergistic classification is achieved by adjusting the classification airflow to match the production capacity of the ultrafine powder mill. Specifically, the primary classifier operates at a speed of 250 r / min, the secondary classifier at 270 r / min, and the classification airflow is 4000 m³ / min. 3 / h, the primary classification removes coarse powder with D90≥20μm and returns it to the ultrafine grinding step for re-grinding, and the secondary classification controls the fine powder D90≤12μm, with a product yield of 93%; The fine powder is compounded and modified to form a modified filler; the compounding modification uses a compound modifier, which includes 0.4 kg titanate coupling agent and 0.3 kg calcium stearate, the mixing temperature is 62℃ and the mixing time is 9 min; The modified filler was homogenized and packaged to obtain a composite filler.

[0055] Example 4 Application of composite fillers in rubber products; 3 kg of steel slag powder (D90=32μm), 2 kg of granulated blast furnace slag powder (D90=30μm) and 95 kg of carbon-containing secondary resources (D90=29μm) were pretreated and then batched to obtain a raw material mixture; The raw material mixture was subjected to ultrafine grinding at a feed rate of 1.2 t / h for 1.6 h. Inert gas was introduced during the grinding process, and the grinding current was adjusted to 152 A in real time using online particle size monitoring to ensure that the D90 of the ultrafine powder was 12.5 μm and the specific surface area was 880 m². 2 / kg, to obtain ultrafine powder; the ultrafine grinding adopts a grinding method with a classifying liner, and the steel ball gradation of the grinding method is Φ10mm:Φ15mm:Φ20mm=3:5:2; Ultrafine powders are synergistically classified to separate fine powders of the target particle size. This synergistic classification is achieved by adjusting the classification airflow to match the production capacity of the ultrafine powder mill. Specifically, the primary classifier operates at a speed of 250 r / min, the secondary classifier at 270 r / min, and the classification airflow is 4000 m³ / min. 3 / h, the primary classification removes coarse powder with D90≥20μm and returns it to the ultrafine grinding step for re-grinding, and the secondary classification controls the fine powder D90≤12μm, with a product yield of 93%; The fine powder is compounded and modified to form a modified filler; the compounding modification uses a compound modifier, which includes 0.6 kg of titanate coupling agent and 0.1 kg of calcium stearate, the mixing temperature is 62℃ and the mixing time is 9 min; The modified filler was homogenized and packaged to obtain a composite filler.

[0056] Comparative Example 1 70 kg of steel slag powder (D90=32μm), 27 kg of granulated blast furnace slag powder (D90=30μm) and 3 kg of carbon-containing secondary resources (D90=28μm) were pretreated and then batched to obtain a raw material mixture; The raw material mixture was subjected to ultrafine grinding at a feed rate of 1.3 t / h for 1.8 h. Inert gas was introduced during the grinding process, and the grinding current was adjusted to 155 A in real time using online particle size monitoring to ensure that the D90 of the ultrafine powder was 13.2 μm and the specific surface area was 850 m². 2 / kg, to obtain ultrafine powder; the ultrafine grinding adopts a grinding method with a classifying liner, and the steel ball gradation of the grinding method is Φ10mm:Φ15mm:Φ20mm=3:5:2; Ultrafine powders are synergistically classified to separate fine powders of the target particle size. This synergistic classification is achieved by adjusting the classification airflow to match the production capacity of the ultrafine powder mill. Specifically, the primary classifier operates at a speed of 260 r / min, the secondary classifier at 280 r / min, and the classification airflow is 4200 m³ / min. 3 / h, the primary classification removes coarse powder with D90≥20μm and returns it to the ultrafine grinding step for re-grinding, and the secondary classification controls the fine powder D90≤12μm, with a product yield of 92%; The fine powder is compounded and modified to form a modified filler; the compounding modification uses a compound modifier, which is 0.65 kg of silane coupling agent, the mixing temperature is 65℃, and the mixing time is 10 min. The modified filler was homogenized and packaged to obtain a composite filler.

[0057] Comparative Example 2 70 kg of steel slag powder (D90=32μm), 27 kg of granulated blast furnace slag powder (D90=30μm) and 3 kg of carbon-containing secondary resources (D90=28μm) were pretreated and then batched to obtain a raw material mixture; The raw material mixture was subjected to ultrafine grinding at a feed rate of 1.3 t / h for 1.8 h. Inert gas was introduced during the grinding process, and the grinding current was adjusted to 155 A in real time using online particle size monitoring to ensure that the D90 of the ultrafine powder was 13.2 μm and the specific surface area was 850 m². 2 / kg, to obtain ultrafine powder; the ultrafine grinding adopts a grinding method with a classifying liner, and the steel ball gradation of the grinding method is Φ10mm:Φ15mm:Φ20mm=3:5:2; Ultrafine powders are synergistically classified to separate fine powders of the target particle size. This synergistic classification is achieved by adjusting the classification airflow to match the production capacity of the ultrafine powder mill. Specifically, the primary classifier operates at a speed of 260 r / min, the secondary classifier at 280 r / min, and the classification airflow is 4200 m³ / min. 3 / h, the primary classification removes coarse powder with D90≥20μm and returns it to the ultrafine grinding step for re-grinding, and the secondary classification controls the fine powder D90≤12μm, with a product yield of 92%; The fine powder is compounded and modified to form a modified filler; the compounding modification uses a compound modifier, which is 0.65 kg of titanate coupling agent, the mixing temperature is 65℃, and the mixing time is 10 min. The modified filler was homogenized and packaged to obtain a composite filler.

[0058] Comparative Example 3 3 kg of steel slag powder (D90=32μm), 2 kg of granulated blast furnace slag powder (D90=30μm) and 95 kg of carbon-containing secondary resources (D90=29μm) were pretreated and then batched to obtain a raw material mixture; The raw material mixture was ground in a vertical mill with a power of 180kW and a rotation speed of 15r / min. Inert gas was introduced during the grinding process. The grinding current was adjusted to 152A in real time through online particle size monitoring. The powder had a D90 of 12.5μm and a specific surface area of ​​880m². 2 / kg, to obtain powder; The powder is co-classified to separate fine powder of the target particle size. Co-classification is achieved by adjusting the classifying airflow to match the capacity of the ultrafine mill. Specifically, the primary classifier operates at a speed of 250 r / min, the secondary classifier at 270 r / min, and the classifying airflow is 4000 m³ / min. 3 / h, the primary classification removes coarse powder with D90≥20μm and returns it to the ultrafine grinding step for re-grinding, and the secondary classification controls the fine powder D90≤12μm, with a product yield of 93%; The fine powder is compounded and modified to form a modified filler; wherein the compound modifier includes 0.4 kg titanate coupling agent and 0.3 kg titanate coupling agent, the mixing temperature is 62℃ and the mixing time is 9 min; The modified filler was homogenized and packaged to obtain a composite filler.

[0059] Comparative Example 4 3 kg of steel slag powder (D90=32μm), 2 kg of granulated blast furnace slag powder (D90=30μm) and 95 kg of carbon-containing secondary resources (D90=29μm) were pretreated and then batched to obtain a raw material mixture; The raw material mixture was subjected to ultrafine grinding at a feed rate of 1.2 t / h for 1.6 h. Inert gas was introduced during the grinding process, and the grinding current was adjusted to 152 A in real time using online particle size monitoring to ensure that the D90 of the ultrafine powder was 12.5 μm and the specific surface area was 880 m². 2 / kg, to obtain ultrafine powder; the ultrafine grinding adopts a grinding method with a classifying liner, and the steel ball gradation of the grinding method is Φ10mm:Φ15mm:Φ20mm=3:5:2; Ultrafine powders are synergistically classified to separate fine powders of the target particle size. This synergistic classification is achieved by adjusting the classification airflow to match the production capacity of the ultrafine powder mill. Specifically, the primary classifier operates at a speed of 250 r / min, the secondary classifier at 270 r / min, and the classification airflow is 4000 m³ / min. 3 / h, the primary classification removes coarse powder with D90≥20μm and returns it to the ultrafine grinding step for re-grinding, and the secondary classification controls the fine powder D90≤12μm, with a product yield of 93%; The fine powder is compounded and modified to form a modified filler; the compounding modification uses a compound modifier, which is 0.7 kg of calcium stearate, the mixing temperature is 62℃, and the mixing time is 9 min. The modified filler was homogenized and packaged to obtain a composite filler.

[0060] The performance of the embodiments and comparative examples is shown in Table 1.

[0061] Table 1

[0062] The data tables above provide a clear comparison of the differences between various embodiments and comparative examples. The following conclusions can be drawn: As can be seen from Examples 1-2 and Comparative Examples 1-2, the contact angle of Examples 1-2 is ≥38°, which blocks the water molecule penetration path, so that the epoxy primer has stable salt spray resistance for more than 800h and the adhesion remains at level 0; while the contact angle of Comparative Examples 1-2 is ≤32°, which leads to an increase in the hydrophilicity of the coating, and the salt spray resistance drops sharply to 500h~550h and the adhesion is downgraded.

[0063] As can be seen from Examples 3-4 and Comparative Examples 3-4, Examples 3-4 significantly improved the rubber reinforcement efficiency by synergistically controlling the powder particle size D90≤15μm and the oil absorption value ≤45g / 100g, with the tensile strength increasing by 15%~28%; while the powder particle size D90 of Comparative Example 3 was 21μm, resulting in a significant decrease in the reinforcement effect; although the powder particle size of Comparative Example 4 was qualified, the oil absorption value was too low, which weakened the interfacial bonding force between the composite filler and the rubber, resulting in a tensile strength increase of 8%.

[0064] One or more technical solutions in the embodiments of the present invention have at least the following technical effects or advantages: This invention provides a method for preparing a highly dispersible composite filler. Through a synergistic process of ultrafine powder and compound modification, three core advantages are simultaneously achieved: In terms of environmental benefits, energy consumption is significantly reduced by 37.5%~50%, and carbon emissions are reduced by 60%~67%; in terms of product performance, it overcomes the bottleneck of adaptability to multiple scenarios with a single material, achieving salt spray resistance ≥800h in anti-corrosion coatings and tensile strength improvement ≥25% in rubber; in terms of economic benefits, the production cost per ton is reduced by 40%~50% compared to imported fillers, and the production cycle is shortened by 50%. Ultimately, with the technical barrier of filler coverage rate ≥92% as the core, a new path for the high-value application of metallurgical solid waste is opened.

[0065] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed in this application.

Claims

1. A method for preparing a highly dispersible composite filler, characterized in that, The method includes: Steel slag powder, granulated blast furnace slag powder and carbon-containing secondary resources are batched to obtain a raw material mixture; The raw material mixture is subjected to ultrafine grinding to obtain ultrafine powder; the ultrafine grinding adopts a grinding method with a grading liner, and the steel ball gradation of the grinding method is Φ10mm:Φ15mm:Φ20mm=3:5:2; The ultrafine powder is synergistically classified to separate fine powder of the target particle size; the synergistic classification is achieved by adjusting the classification air volume to match the production capacity of the ultrafine powder mill. The fine powder is compounded and modified to form a modified filler; the compounding modification uses a compounding modifier, which includes a combination of silane coupling agent, titanate coupling agent and polyethylene glycol, or a combination of titanate coupling agent and calcium stearate. The modified filler was homogenized and packaged to obtain a composite filler.

2. The preparation method according to claim 1, characterized in that, In the batching step, the steel slag powder has a mass fraction of 60%~75%, the granulated blast furnace slag powder has a mass fraction of 20%~35%, and the carbon-containing secondary resources have a mass fraction of 3%~5%; or... The mass fraction of the carbon-containing secondary resources is 90%~98%, the mass fraction of the steel slag powder is 1%~5%, and the mass fraction of the granulated blast furnace slag powder is 1%~5%.

3. The preparation method according to claim 1, characterized in that, In the batching step, the steel slag powder, the granulated blast furnace slag powder, and the carbon-containing secondary resources all meet the following requirements: mesh size ≥ 400 mesh, D90 ≤ 35 μm, and moisture content ≤ 0.8%.

4. The preparation method according to claim 1, characterized in that, In the ultrafine grinding step, the feed rate of the grinding method is 1.2t / h to 1.5t / h, the grinding time is 1.5h to 2.0h, inert gas is introduced during the grinding process, and the grinding current is adjusted to 150A to 160A in real time through online particle size monitoring to ensure that the D90 of the ultrafine powder is ≤15μm.

5. The preparation method according to claim 1, characterized in that, In the aforementioned collaborative grading step, the grading air volume is 4000 m³ / h. 3 / h~4500m 3 / h, the first-stage classification removes coarse powder with D90≥20μm and returns it to the ultrafine grinding step for re-grinding, the second-stage classification controls the fine powder D90≤12μm, and the product yield is 90%~95%.

6. The preparation method according to claim 1, characterized in that, In the compound modification step, the compound modifier includes a combination of silane coupling agent KH-550, titanate coupling agent NDZ-311 and polyethylene glycol PEG-400. The mass fraction of the silane coupling agent KH-550 is 0.2%~0.5%, the mass fraction of the titanate coupling agent NDZ-311 is 0.1%~0.3%, and the mass fraction of the polyethylene glycol PEG-400 is 0.1%~0.2%; or, The compound modifier comprises a combination of titanate coupling agent NDZ-201 and calcium stearate, wherein the mass fraction of titanate coupling agent NDZ-201 is 0.3%~0.6% and the mass fraction of calcium stearate is 0.2%~0.4%.

7. The preparation method according to claim 1, characterized in that, In the compound modification step, the mixing temperature is 60℃~70℃, the mixing time is 8min~12min, and the coating rate of the modifier is ≥92%.

8. The preparation method according to claim 1, characterized in that, The ingredient preparation step is preceded by a raw material pretreatment step. The raw material pretreatment includes: removing iron from the steel slag powder by magnetic separation to an iron content ≤0.5%; removing impurities from the granulated blast furnace slag powder by air separation to an impurity content ≤0.3%; and drying the carbon-containing secondary resources to a moisture content ≤0.8%.

9. The preparation method according to claim 1, characterized in that, The composite filler product has a D90 ≤ 15μm, a 45μm sieve residue ≤ 0.08%, an oil absorption value ≤ 55g / 100g, and a bulk density ≤ 2.3g / cm³. 3 Contact angle ≥35°, moisture content ≤0.8%.

10. The preparation method according to claim 1, characterized in that, In the homogenization and packaging step, the modified powder is homogenized after being cooled to room temperature, with batch-to-batch performance fluctuations ≤3% and packaging accuracy ±0.2%. The coordinated classification step is followed by a pulse dust collection step, with the exhaust dust concentration ≤8mg / m³. 3 .

Images