Method for preparing flame-retardant PP composite material from fly ash
Flame-retardant PP composite materials were prepared by magnetic separation and ultrafine grinding modification, which solved the problems of fly ash accumulation and pollution, realized high added value utilization and environmental protection, and improved material performance.
Patent Information
- Application Number
- CN202511893083.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-16
- Publication Date
- 2026-02-13
AI Technical Summary
Fly ash accumulates in large quantities, pollutes the environment, and cannot be utilized for high added value. Existing technologies mainly use it in building materials, resulting in serious resource waste.
Flame-retardant PP composite materials are prepared by removing magnetic iron-containing minerals from fly ash through magnetic separation, followed by ultrafine grinding and surface modification. Flame-retardant additives are then prepared using fly ash to improve its compatibility and flame-retardant properties in polymers.
This approach enables the high-value utilization of fly ash, solves environmental pollution problems, improves the flame retardant and overall performance of composite materials, reduces costs, and complies with resource utilization policies.
Smart Images
Figure CN121517816A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of comprehensive utilization of solid waste, and particularly relates to a method for preparing a flame-retardant PP composite material from fly ash. BACKGROUND
[0002] Fly ash is an industrial waste residue generated by coal-fired power plants, and its accumulation is huge. It not only occupies a large amount of farmland, seriously pollutes the ecological environment, but also brings potential harm to human health. Therefore, the disposal and comprehensive utilization of fly ash have always been concerned. At present, fly ash is mainly made into building materials for road paving and road backfill engineering, etc., and cannot be used for high value-added utilization, resulting in waste of resources. Therefore, it is necessary to develop a high-value utilization approach for fly ash to turn waste into treasure, which can not only generate certain benefits, but also solve the pollution problem caused by the storage of fly ash solid waste to the environment. SUMMARY
[0003] In view of the above technical problems, the present application provides a method for preparing a flame-retardant PP composite material from fly ash.
[0004] In order to achieve the above purpose, the technical scheme of the present application is as follows: A method for preparing a flame-retardant PP composite material from fly ash, comprising the following steps: S1, fly ash pretreatment, removing magnetic iron-containing minerals in the fly ash by using a magnetic separation device; S2, fly ash superfine grinding, grinding the pretreated fly ash to 3-15 microns to prepare fly ash superfine powder, meeting the fineness requirement of inorganic mineral filler; S3, surface modification of fly ash superfine powder, placing the fly ash superfine powder in an oil bath pot, adding a modifier for heating and stirring to uniformly mix, and performing dry organic modification on the fly ash superfine powder, wherein the amount of the modifier is 1.1-1.3wt%, and the heating and stirring temperature is 80-100℃; S4, preparation of flame-retardant filler by compounding fly ash modified powder, wherein the fly ash modified powder and the flame-retardant additive are compounded into flame-retardant powder filler in proportion, and the proportion of the fly ash modified powder and the flame-retardant additive is 25-30phr and 8-10phr; S5, preparation of fly ash-based PP composite material, adding the flame-retardant filler to the PP in an amount of 30-50phr, and adding the PP in an amount of 70-50phr, then feeding into a reaction kettle, uniformly heating and stirring in the reaction kettle, and then feeding into an extruder in a molten state after cooling the mixture to obtain a fly ash-based PP composite material, wherein the heating and stirring temperature is 70-90℃.
[0005] The step S1 is specifically adopting a spiral dry magnetic separator to remove the magnetic iron-containing mineral in the fly ash through two-stage magnetic separation, wherein the field strength of the spiral dry magnetic separator is 3000-4000Gs.
[0006] The step S2 is specifically adopting a Raymond mill to perform closed-circuit grinding on the pretreated fly ash.
[0007] The modifier in the step S3 is octadecylamine.
[0008] The stirring time in the step S3 is 30-50 min, and the stirring speed is 900-1100 r / min.
[0009] The flame-retardant additive in the step S4 is prepared by proportioning a flame retardant and a flame-retardant synergist, wherein the flame retardant is decabromodiphenyl ethane, the flame-retardant synergist is antimony trioxide, and the proportion of decabromodiphenyl ethane to antimony trioxide is 3:1.
[0010] The stirring speed in the step S5 is 1000-1200 r / min, and the stirring time is 40-60 min.
[0011] After the mixture is cooled, the double-screw extruder is used to extrude in a molten state at a screw speed of 30 r / min.
[0012] The present application has the following advantages: 1. In the present application, the magnetic iron-containing mineral in the fly ash is removed by a two-stage dry spiral magnetic separator, thereby reducing the self-agglomeration phenomenon and preventing the influence of the iron-containing mineral on the performance of the filler.
[0013] 2. In the present application, the fly ash is ground by a Raymond mill closed-circuit grinding process, thereby reducing the grinding energy consumption and improving the grinding efficiency while performing the ultra-fine grinding and particle size classification. The surface structure of the particles is activated by the ultra-fine processing, thereby improving the compatibility of the fly ash and the polymer. With the decrease of the particle size, the surface electron structure and the crystal structure of the particles change, thereby producing the surface effect, small-size effect, quantum effect and macroscopic quantum tunnel effect that the coarse particles do not have, so that the ultra-fine powder has a series of excellent physical and chemical properties compared with the conventional particle materials, such as the increase of the specific surface area, the increase of the surface high-energy free radicals and the active points on the surface, and the increase of the stability of the combination interface between the particles and other substances, the uniformity and stability of the system.
[0014] 3. The present application realizes the high-value utilization of the industrial solid waste, solves the influence of the solid waste storage on the environment, and provides a new way for the high-value comprehensive utilization of the solid waste resources.
[0015] 4. This invention, through pretreatment, ultrafine grinding, and surface modification, can significantly improve the compatibility between inorganic fillers and polymers, and further enhance the flame retardant properties and overall performance of the composite material.
[0016] 5. This invention enables the organic modification of inorganic mineral fly ash, achieving chemical bonding between inorganic fillers and matrix materials, improving the compatibility between fly ash fillers and polymers, enhancing the interfacial bonding between the two, ensuring the dispersion state of fillers in polymers, achieving the filling effect, and also playing a reinforcing role, improving the flame retardant properties and comprehensive performance of composite materials.
[0017] 6. This invention can use fly ash to replace high-grade modified talc or activated kaolin in ABS, PP and other plastic products. Fly ash itself is solid waste and needs to be reduced. The raw material is easy to obtain and has no cost. The flame-retardant composite material prepared by using fly ash has a lower cost and can also create higher economic benefits. It solves the problems of low added value utilization of fly ash and environmental pollution caused by stockpiling, which is in line with the national policy requirements for solid waste reduction and resource utilization. Attached Figure Description
[0018] Figure 1 This is a process flow diagram of the present invention. Detailed Implementation
[0019] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments. It should be understood that these descriptions are merely exemplary and not intended to limit the scope of the invention. Furthermore, descriptions of well-known structures and technologies are omitted in the following description to avoid unnecessarily obscuring the concepts of the invention.
[0020] Example 1 like Figure 1 As shown, a method for preparing flame-retardant PP composite material from fly ash includes the following steps: S1. Fly ash pretreatment: magnetic separation equipment is used to remove magnetic iron-containing minerals from fly ash. S2. Ultrafine grinding of fly ash: The pretreated fly ash is ground to 3μm to prepare ultrafine fly ash powder, which meets the fineness requirements of inorganic mineral fillers. S3. Surface modification of fly ash ultrafine powder: Fly ash ultrafine powder is placed in an oil bath, a modifier is added, and the mixture is heated and stirred until homogeneous. The fly ash ultrafine powder is subjected to dry organic modification. The amount of modifier is 1.1 wt%, and the heating and stirring temperature is 80℃. S4. Flame-retardant filler prepared by compounding modified fly ash micro powder: modified fly ash micro powder and flame-retardant additive are compounded in a certain proportion to form flame-retardant micro powder filler, wherein the ratio of modified fly ash micro powder to flame-retardant additive is 25 phr and 8 phr. S5. Preparation of fly ash-based PP composite material: Flame-retardant filler is added to PP at a rate of 30 phr, and the PP addition amount is 70 phr. Then, it is sent to a reactor and heated and stirred evenly in the reactor. After the mixture is cooled, it is added to an extruder and extruded in a molten state to obtain fly ash-based PP composite material. The heating and stirring temperature is 70℃.
[0021] In step S1, a spiral dry magnetic separator is used to remove magnetic iron-containing minerals from fly ash through two-stage magnetic separation. The field strength of the spiral dry magnetic separator is 3000 Gs.
[0022] Specifically, in step S2, a Raymond mill is used to perform closed-circuit grinding on the pretreated fly ash.
[0023] In step S3, the modifier is octadecylamine.
[0024] In step S3, the stirring time is 30 minutes and the stirring speed is 900 r / min.
[0025] In step S4, the flame retardant additive is prepared by mixing a flame retardant and a flame retardant synergist in a certain proportion. The flame retardant is decabromodiphenyl ethane, and the flame retardant synergist is antimony trioxide. The ratio of decabromodiphenyl ethane to antimony trioxide is 3:1.
[0026] In step S5, the stirring speed is 1000 r / min and the stirring time is 40 min.
[0027] In step S5, the mixture is cooled and then fed into a twin-screw extruder and extruded in a molten state at a screw speed of 30 r / min.
[0028] Example 2 like Figure 1 As shown, a method for preparing flame-retardant PP composite material from fly ash includes the following steps: S1. Fly ash pretreatment: magnetic separation equipment is used to remove magnetic iron-containing minerals from fly ash. S2. Ultrafine grinding of fly ash: Grind the pretreated fly ash to 15μm to prepare ultrafine fly ash powder, which meets the fineness requirements of inorganic mineral fillers. S3. Surface modification of fly ash ultrafine powder: Fly ash ultrafine powder is placed in an oil bath, a modifier is added, and the mixture is heated and stirred until homogeneous. The fly ash ultrafine powder is then subjected to dry organic modification. The amount of modifier is 1.3 wt%, and the heating and stirring temperature is 100℃. S4. Flame-retardant filler prepared by compounding modified fly ash micro powder: modified fly ash micro powder and flame-retardant additive are compounded in a certain proportion to form flame-retardant micro powder filler, wherein the ratio of modified fly ash micro powder to flame-retardant additive is 30 phr and 10 phr. S5. Preparation of fly ash-based PP composite material: Flame-retardant filler is added to PP at a rate of 50 phr. The PP addition amount is 50 phr. Then, it is sent to a reactor and heated and stirred evenly in the reactor. After the mixture is cooled, it is added to an extruder and extruded in a molten state to obtain fly ash-based PP composite material. The heating and stirring temperature is 90℃.
[0029] In step S1, a spiral dry magnetic separator is used to remove magnetic iron-containing minerals from fly ash through two-stage magnetic separation. The field strength of the spiral dry magnetic separator is 4000 Gs.
[0030] Specifically, in step S2, a Raymond mill is used to perform closed-circuit grinding on the pretreated fly ash.
[0031] In step S3, the modifier is octadecylamine.
[0032] In step S3, the stirring time is 50 minutes and the stirring speed is 1100 r / min.
[0033] In step S4, the flame retardant additive is prepared by mixing a flame retardant and a flame retardant synergist in a certain proportion. The flame retardant is decabromodiphenyl ethane, and the flame retardant synergist is antimony trioxide. The ratio of decabromodiphenyl ethane to antimony trioxide is 3:1.
[0034] In step S5, the stirring speed is 1200 r / min and the stirring time is 60 min.
[0035] In step S5, the mixture is cooled and then fed into a twin-screw extruder and extruded in a molten state at a screw speed of 30 r / min.
[0036] Example 3 The fly ash described in this embodiment is produced by the Jiuquan Iron and Steel Group Thermal Power Plant, and its particle size is D80 < 400 mesh. The process includes the following steps: S1: Fly ash pretreatment, using a spiral dry magnetic separator to remove magnetite from the fly ash through two-stage magnetic separation. After testing, the iron content in the fly ash after iron removal was reduced from 10.5% to 4.16%.
[0037] S2: Ultrafine grinding of fly ash, using Raymond mill to grind pretreated fly ash to 15μm content of 90%.
[0038] S3: Surface modification of fly ash micropowder. Ultrafine fly ash powder was placed in an oil bath, and octadecylamine was added and heated with stirring to modify the powder. The dosage of octadecylamine was 1.2 wt%, the modification temperature was 90℃, the modification time was 40 min, and the stirring speed was 1000 r / min. The tested results showed an activity index of 99.01% and an oil absorption value of 25.1 g / 100g, meeting the high-quality requirements of commonly used inorganic mineral fillers.
[0039] S4: The ratio of modified fly ash powder to flame retardant additive is 30 phr and 10 phr, respectively. The modified fly ash powder is then compounded with flame retardant filler. The flame retardant additive is prepared by mixing the flame retardant decabromodiphenyl ethane and the flame retardant synergist antimony trioxide in a 3:1 ratio.
[0040] S5: Preparation of fly ash-based PP composite material: Flame-retardant filler was added to PP at a rate of 40 phr. The PP addition amount was 40 phr. Then, the mixture was sent to a reactor for heating and stirring. The heating temperature was 80℃, the stirring speed was 1100 r / min, and the pressure stirring time was 50 min. After the mixture cooled, it was added to a twin-screw extruder at a speed of 30 r / min to obtain fly ash-based polypropylene composite material.
[0041] The fly ash-based composite material underwent limiting oxygen index (LOI) testing and UL-94 vertical flammability testing. The LIO index of the composite material reached 27.2%, and the flammability rating reached V-0, meaning the composite material cannot be ignited. The corresponding impact strength, flexural strength, flexural modulus, and tensile strength of the composite material were 22.37 KJ / m2, 50.10 MPa, 1650.18 MPa, and 40.13 MPa, respectively, meeting the strength requirements of the corresponding products.
[0042] It should be understood that the specific embodiments described above are merely illustrative or explanatory of the principles of the invention and do not constitute a limitation thereof. Therefore, any modifications, equivalent substitutions, improvements, etc., made without departing from the spirit and scope of the invention should be included within the protection scope of the invention. Furthermore, the appended claims are intended to cover all variations and modifications falling within the scope and boundaries of the appended claims, or equivalent forms of such scope and boundaries.
Claims
1. A method for preparing flame-retardant PP composite material from fly ash, characterized in that, Includes the following steps: S1. Fly ash pretreatment: magnetic separation equipment is used to remove magnetic iron-containing minerals from fly ash. S2. Ultrafine grinding of fly ash: Grind the pretreated fly ash to 3-15μm to prepare ultrafine fly ash powder, which meets the fineness requirements of inorganic mineral fillers. S3. Surface modification of fly ash ultrafine powder: Place fly ash ultrafine powder in an oil bath, add modifier and heat and stir to mix evenly, and perform dry organic modification of fly ash ultrafine powder. The amount of modifier is 1.1-1.3wt% and the heating and stirring temperature is 80-100℃. S4. Flame-retardant filler prepared by compounding modified fly ash micro powder: modified fly ash micro powder and flame-retardant additive are compounded in proportion to form flame-retardant micro powder filler, wherein the ratio of modified fly ash micro powder to flame-retardant additive is 25-30 phr and 8-10 phr, respectively. S5. Preparation of fly ash-based PP composite material: Flame-retardant filler is added to PP at a rate of 30-50 phr, and the PP addition amount is 70-50 phr. Then, it is sent to a reactor and heated and stirred evenly in the reactor. After the mixture is cooled, it is added to an extruder and extruded in a molten state to obtain fly ash-based PP composite material. The heating and stirring temperature is 70-90℃.
2. The method for preparing flame-retardant PP composite material from fly ash according to claim 1, characterized in that, In step S1, a spiral dry magnetic separator is used to remove magnetic iron-containing minerals from fly ash through two-stage magnetic separation. The field strength of the spiral dry magnetic separator is 3000-4000 Gs.
3. The method for preparing flame-retardant PP composite material from fly ash according to claim 1, characterized in that, In step S2, the pretreated fly ash is specifically ground in a closed circuit using a Raymond mill.
4. The method for preparing flame-retardant PP composite material from fly ash according to claim 1, characterized in that, In step S3, the modifier is octadecylamine.
5. The method for preparing flame-retardant PP composite material from fly ash according to claim 1, characterized in that, In step S3, the stirring time is 30-50 min and the stirring speed is 900-1100 r / min.
6. The method for preparing flame-retardant PP composite material from fly ash according to claim 1, characterized in that, In step S4, the flame retardant additive is prepared by mixing a flame retardant and a flame retardant synergist in a certain proportion. The flame retardant is decabromodiphenyl ethane, and the flame retardant synergist is antimony trioxide. The ratio of decabromodiphenyl ethane to antimony trioxide is 3:
1.
7. The method for preparing flame-retardant PP composite material from fly ash according to claim 1, characterized in that, In step S5, the stirring speed is 1000-1200 r / min and the stirring time is 40-60 min.
8. The method for preparing flame-retardant PP composite material from fly ash according to claim 1, characterized in that, In step S5, after the mixture is cooled, it is fed into a twin-screw extruder and extruded in a molten state at a screw speed of 30 r / min.