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CN-121991441-A - Red mud-based water-absorbing polyvinyl chloride particle material and preparation method thereof

CN121991441ACN 121991441 ACN121991441 ACN 121991441ACN-121991441-A

Abstract

The application belongs to the technical field of red mud-based materials, and particularly relates to a red mud-based water-absorbing polyvinyl chloride particle material and a preparation method thereof. The granular material comprises, by mass, 100 parts of polyvinyl chloride resin, 65-150 parts of red mud powder which is dealkalized, dried and crushed to an average particle size of 5-10 mu m, 3-8 parts of a composite modifier containing at least one of a silane coupling agent and a titanate coupling agent, 3-8 parts of a calcium-zinc composite stabilizer and 1-4 parts of a lubricant, wherein the composite modifier modifies the surface of the red mud powder to form an interface bonding layer with the polyvinyl chloride resin. The obtained granular material has the tensile strength of more than or equal to 25MPa and the water absorption rate of 0.94-1.83 percent, and has mechanical stability and adjustable water absorption, so that the solid waste red mud with low cost is used for highly filling the polyvinyl chloride and maintaining the performance, and the bottlenecks of high cost and difficult utilization of the red mud of the existing calcium carbonate are solved.

Inventors

  • GAO JIANYANG
  • WANG ZHEN
  • HUANG ENJIE
  • ZHANG XIAOYANG
  • HU MUQIU

Assignees

  • 中铝山东有限公司

Dates

Publication Date
20260508
Application Date
20251216

Claims (10)

  1. 1. The red mud-based water-absorbing polyvinyl chloride particle material is characterized by comprising the following components in parts by mass: 100 parts of polyvinyl chloride resin; Dealkalizing, drying and crushing 65-150 parts of red mud powder with the average particle size of 5-10 mu m; 3-8 parts of composite modifier containing at least one of silane coupling agent and titanate coupling agent, and 3-8 Parts of calcium-zinc composite stabilizer and 1-4 Parts of a lubricant; the composite modifier modifies the surface of the red mud powder to enable the red mud powder and the polyvinyl chloride resin to form an interface bonding layer.
  2. 2. The red mud-based water-absorbing polyvinyl chloride granular material according to claim 1, wherein the red mud powder is obtained by drying bayer process red mud to a water content of <1.0% through water elution alkali and at 105-120 ℃ and then through jet milling.
  3. 3. The red mud-based water-absorbent polyvinyl chloride particulate material according to claim 1, wherein the composite modifier is a mixture of 3-aminopropyl triethoxysilane and bis (dioctyl pyrophosphoryloxy) ethylene titanate in a mass ratio of 1:1.
  4. 4. The red mud-based water-absorbent polyvinyl chloride particulate material of claim 1, wherein the lubricant is a composite of polyethylene wax and stearic acid in a mass ratio of 1:1.
  5. 5. The red mud-based water-absorbing polyvinyl chloride particulate material of claim 1, wherein inorganic-organic chemical bridging is formed between the composite modifier and the surface of the red mud powder and between the composite modifier and the polyvinyl chloride resin, and the thickness of the interface bonding layer is 5-50nm.
  6. 6. The red mud-based water-absorbing polyvinyl chloride particulate material of claim 1, wherein the particulate material is a cylindrical particulate material having a diameter of 2-4mm and a length of 3-5 mm.
  7. 7. The red mud-based water-absorbing polyvinyl chloride particulate material according to claim 1, wherein the particulate material has a water absorption of 0.94-1.83%, a tensile strength of 25MPa or more, and an elongation at break of 11% or more.
  8. 8. A process for the preparation of a red mud-based water absorbent polyvinyl chloride particulate material as claimed in any one of claims 1 to 7, characterized in that the process comprises: Sequentially performing water alkali elution, filter pressing, drying at 105-120 ℃ and crushing on Bayer process red mud to obtain red mud powder with an average particle size of 5-10 mu m and a water content of less than 1.0%; premixing the red mud powder with a composite modifier containing at least one of a silane coupling agent and a titanate coupling agent to obtain surface modified red mud powder; Sequentially carrying out high-speed hot mixing and low-speed cold mixing on the surface modified red mud powder, polyvinyl chloride resin, calcium-zinc composite stabilizer and lubricant to obtain a mixture; and (3) carrying out melt extrusion, cooling and granulating on the mixture in a double-screw extruder to obtain the red mud-based water-absorbing polyvinyl chloride particle material.
  9. 9. The method according to claim 7, wherein the high-speed hot-mixing temperature is 115-125 ℃ and the rotation speed is not lower than 800rpm, and the low-speed cold-mixing temperature is 40-50 ℃ and the rotation speed is not higher than 200rpm.
  10. 10. The process according to claim 7, wherein the twin-screw extruder has a screw speed of 200 to 350rpm, a feed stage temperature of 155 to 165 ℃, a compression stage temperature of 165 to 185 ℃, a homogenization stage temperature of 180 to 190 ℃, and a head temperature of 175 to 185 ℃.

Description

Red mud-based water-absorbing polyvinyl chloride particle material and preparation method thereof Technical Field The application belongs to the technical field of red mud-based materials, and particularly relates to a red mud-based water-absorbing polyvinyl chloride particle material and a preparation method thereof. Background The cost of the polyvinyl chloride resin is reduced and the performance is improved by inorganic filler, and the traditional calcium carbonate has weakened the economic advantage due to the continuous rising of the price. Bayer process red mud is a large amount of solid waste in the alumina industry, has the characteristics of high alkali and hydrophilicity, is poor in interfacial compatibility with a hydrophobic polyvinyl chloride matrix, and directly filling the bayer process red mud into polyvinyl chloride resin can cause the negative effects of agglomeration, stress concentration and processing thermal degradation, so that the bayer process red mud cannot be utilized in a recycling way. Disclosure of Invention The embodiment of the application provides a red mud-based water-absorbing polyvinyl chloride particle material and a preparation method thereof, which aim to solve the technical problem of how to fill polyvinyl chloride with Bayer process red mud and maintain performance. In a first aspect, an embodiment of the present application provides a red mud-based water-absorbent polyvinyl chloride particulate material, where the particulate material is composed of the following components in parts by mass: 100 parts of polyvinyl chloride resin; Dealkalizing, drying and crushing 65-150 parts of red mud powder with the average particle size of 5-10 mu m; 3-8 parts of composite modifier containing at least one of silane coupling agent and titanate coupling agent, and 3-8 Parts of calcium-zinc composite stabilizer and 1-4 Parts of a lubricant; the composite modifier modifies the surface of the red mud powder to enable the red mud powder and the polyvinyl chloride resin to form an interface bonding layer. Optionally, the red mud powder is obtained by washing Bayer process red mud with water to remove alkali, drying at 105-120 ℃ until the water content is less than 1.0%, and then carrying out jet milling. Optionally, the composite modifier is a mixture of 3-aminopropyl triethoxysilane and bis (dioctyl pyrophosphoric acid acyloxy) ethylene titanate in a mass ratio of 1:1. Optionally, the lubricant is a composite of polyethylene wax and stearic acid in a mass ratio of 1:1. Optionally, inorganic-organic chemical bridging is formed between the composite modifier and the surface of the red mud powder and between the composite modifier and the polyvinyl chloride resin, and the thickness of the interface bonding layer is 5-50nm. Optionally, the granular material is cylindrical granular material with a diameter of 2-4mm and a length of 3-5 mm. Optionally, the water absorption rate of the granular material is 0.94-1.83%, the tensile strength is more than or equal to 25MPa, and the elongation at break is more than or equal to 11%. In a second aspect, an embodiment of the present application provides a method for preparing the red mud-based water-absorbent polyvinyl chloride particulate material according to any one of the first aspect, where the method includes: Sequentially performing water alkali elution, filter pressing, drying at 105-120 ℃ and crushing on Bayer process red mud to obtain red mud powder with an average particle size of 5-10 mu m and a water content of less than 1.0%; premixing the red mud powder with a composite modifier containing at least one of a silane coupling agent and a titanate coupling agent to obtain surface modified red mud powder; Sequentially carrying out high-speed hot mixing and low-speed cold mixing on the surface modified red mud powder, polyvinyl chloride resin, calcium-zinc composite stabilizer and lubricant to obtain a mixture; and (3) carrying out melt extrusion, cooling and granulating on the mixture in a double-screw extruder to obtain the red mud-based water-absorbing polyvinyl chloride particle material. Optionally, the temperature of the high-speed hot mixing is 115-125 ℃, the rotating speed is not lower than 800rpm, the temperature of the low-speed cold mixing is 40-50 ℃, and the rotating speed is not higher than 200rpm. Optionally, the screw speed of the double screw extruder is 200-350rpm, the temperature of the feeding section is 155-165 ℃, the temperature of the compression section is 165-185 ℃, the temperature of the homogenizing section is 180-190 ℃, and the temperature of the machine head is 175-185 ℃. Compared with the prior art, the technical scheme provided by the embodiment of the application has the following advantages: The method comprises the steps of firstly drying and jet-pulverizing red mud with water-washing alkali-105-120 ℃ to 5-10 mu m to remove alkaline catalyst from the source and reduce water content, so as to avoid gasificati