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CN-122013592-A - Composite modified coal-based solid waste filler and preparation method and application thereof

CN122013592ACN 122013592 ACN122013592 ACN 122013592ACN-122013592-A

Abstract

The application discloses a composite modified coal-based solid waste filler and a preparation method and application thereof, and belongs to the technical field of inorganic solid waste recycling and green packaging materials. The process sequentially comprises the steps of acid treatment, alkali treatment, silane coupling agent treatment and cationic polymer treatment for multi-step synergistic modification to obtain composite modified filler, and then mixing the filler with fluffed plant pulp fibers, and carrying out wet forming and drying to obtain the high-performance packaging material. The synergistic modification process realizes high-content (35-55 wt%) filling of coal-based solid waste, and the prepared material has excellent mechanical property and environmental compatibility, namely, the retention rate of wet strength is more than or equal to 70%, and the water absorption rate is less than or equal to 5%.

Inventors

  • MIAO YINGJU
  • WU HONG
  • LEI YIZHU
  • YUAN JIE

Assignees

  • 六盘水师范学院

Dates

Publication Date
20260512
Application Date
20260202

Claims (10)

  1. 1. The preparation method of the composite modified coal-based solid waste filler is characterized in that acid treatment, alkali treatment, silane coupling agent treatment and cationic polymer treatment are sequentially carried out on coal-based solid waste to obtain the composite modified coal-based solid waste filler; the concentration of the acid solution adopted in the acid treatment is 0.5-5 wt%, and the treatment temperature is 20-80 ℃; the alkali concentration adopted in the alkali treatment is 1-10 wt%, and the treatment temperature is 40-90 ℃; The silane coupling agent treatment is to add the coal-based solid waste subjected to alkali treatment into the silane coupling agent subjected to pre-hydrolysis for reaction; the cationic polymer is a polymer containing quaternary ammonium salt groups.
  2. 2. The method according to claim 1, wherein the coal-based solid waste is at least one selected from fly ash, gasified slag and coal gangue, and has a particle diameter d90 less than or equal to 100 μm.
  3. 3. The plant fiber-based packaging material is characterized by comprising the following raw materials, by weight, 45-90 parts of plant fibers and 35-55 parts of composite modified coal-based solid waste fillers; The composite modified coal-based solid waste filler is obtained by the preparation method of any one of claims 1-2.
  4. 4. The plant fiber-based packaging material according to claim 3, wherein the raw material comprises 45-65 parts of plant fiber and 35-55 parts of composite modified coal-based solid waste filler.
  5. 5. The plant fiber based packaging material according to claim 3, wherein the raw material further comprises one or more of the following auxiliary agents, namely 0.5-2.0 parts of wet strength agent, 0.1-0.5 parts of retention and drainage aid, and 0.5-3.0 parts of softening agent.
  6. 6. A method of preparing a plant fiber based packaging material according to any one of claims 3 to 5, comprising the steps of: S1, mixing the composite modified coal-based solid waste filler obtained by the preparation method of any one of claims 1 or 2 with fluffed plant fibers to form composite slurry; s2, carrying out wet forming on the composite slurry in the S1, and drying to obtain the plant fiber-based packaging material.
  7. 7. The method of claim 6, wherein the composite modified coal-based solid waste filler is present in the plant fiber-based packaging material in an amount of 10% to 55% by mass.
  8. 8. The method of claim 7, wherein the mass percentage is 35% -55%.
  9. 9. The method according to claim 6, wherein the wet forming in S2 includes the steps of subjecting the composite slurry to primary solid-liquid separation, collecting filtrate resulting from the primary solid-liquid separation, and recycling the filtrate for the re-forming of the same batch of slurry.
  10. 10. Use of the composite modified coal-based solid waste filler obtained by the preparation method according to any one of claims 1 or 2 for preparing a plant fiber-based packaging material.

Description

Composite modified coal-based solid waste filler and preparation method and application thereof Technical Field The application belongs to the technical field of inorganic solid waste recycling and green composite packaging materials, and particularly relates to a composite modified coal-based solid waste filler, and a preparation method and application thereof. Background With the intensive and sustainable development concept of global environmental protection regulations, development of completely biodegradable and renewable green packaging materials has become an urgent need. Paper-based packaging materials (e.g., pulp molded articles made from waste paper fibers, cardboard, etc.) based on plant fibers are considered as an important alternative to conventional plastics due to their recyclability and degradability. The current disposal mode (piling or low-added value building material utilization) has the problems of low environmental risk and low economic benefit. Therefore, the searching of a new way for high-valued and large-scale utilization of coal-based solid wastes is significant. The coal-based solid waste is used as filler to be applied to the plant fiber-based composite material, so that the aim of reducing cost can be fulfilled. But the interfacial compatibility between the coal-based solid wastes (hydrophilic inorganic matters) and plant fibers is extremely poor. The direct mixing can not be enhanced, but can damage the hydrogen bond network among fibers, so that the mechanical property of the composite material is seriously reduced, and the problem of filler falling (powder falling) is caused. Particularly, when the wet method is adopted to prepare the composite material with high filler content, the modified filler particles are tiny, so that the modified filler particles are very easy to run off along with water in the forming and dewatering process, the actual filler content of the product is far lower than a design value, and the consistency of the performance and the utilization rate of the material are seriously affected. The prior art has often addressed this problem by adding excess retention aid or using extremely expensive special forming equipment, resulting in high costs and environmental protection. To improve compatibility, the prior art generally employs a single physical or chemical modification method, or a combination of simple steps. However, conventional methods have the further limitation that, firstly, they generally rely on a single mechanism of action, and are difficult to cope with complex interfacial stresses at high loadings, especially in wet environments. Secondly, the prior art does not consider the coordination effect among the modification steps aiming at special fillers with complex surface components and nonuniform activity such as coal-based solid wastes. Finally, the existing method lacks systematic design, and cannot construct a multiple and composite interface structure integrating physical anchoring, chemical bonding and strong electrostatic adsorption between the filler and the fiber. Therefore, the prior art has difficulty in realizing high-proportion filling (such as more than 30 percent, particularly high content reaching 35 to 55 percent) of coal-based solid waste, simultaneously ensuring that the composite material has excellent comprehensive properties, particularly high wet strength retention rate (more than or equal to 70 percent) and low water absorption rate (less than or equal to 5 percent), and avoiding the occurrence of powder falling. In view of the foregoing, there is a need for a process and a composite material preparation method that can solve the above problems, so as to prepare a degradable environment-friendly packaging material with excellent performance and controllable cost while realizing high-value utilization of coal-based solid waste. Disclosure of Invention In order to achieve the above purpose, the application provides a preparation method of composite modified coal-based solid waste filler, which comprises the steps of sequentially carrying out acid treatment, alkali treatment, silane coupling agent treatment and cationic polymer treatment on coal-based solid waste to obtain composite modified coal-based solid waste filler; the concentration of the acid solution adopted in the acid treatment is 0.5-5 wt%, and the treatment temperature is 20-80 ℃; the alkali concentration adopted in the alkali treatment is 1-10 wt%, and the treatment temperature is 40-90 ℃; The silane coupling agent treatment is to add the coal-based solid waste subjected to alkali treatment into the silane coupling agent subjected to pre-hydrolysis for reaction; the cationic polymer is a polymer containing quaternary ammonium salt groups. Further, the coal-based solid waste is at least one selected from fly ash, gasified slag and coal gangue, and the grain diameter D90 of the coal-based solid waste is less than or equal to 100 mu m. Further, the plant fibe