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CN-115873302-B - Red mud-based nano flame retardant, and preparation method and application thereof

CN115873302BCN 115873302 BCN115873302 BCN 115873302BCN-115873302-B

Abstract

The invention belongs to the technical field of flame retardance, and particularly relates to a red mud-based nano flame retardant, and a preparation method and application thereof. According to the invention, red mud and a carbonaceous reducing agent are mixed for reduction roasting, iron oxide in the red mud is reduced into metallic iron, then monomer dissociation of the metallic iron is realized through crushing and grinding, then magnetic separation is carried out, magnetic product metallic iron and non-magnetic product aluminum rich slag (mainly containing aluminum oxide) are obtained through separation, then mechanochemical reaction is carried out on the aluminum rich slag, a magnesium additive and water in CO 2 atmosphere, and aluminum oxide in the aluminum rich slag and magnesium in the magnesium additive react with water and carbon dioxide under the mechanochemical action to form magnesium aluminum carbonate hydrotalcite, so that the red mud-based nano flame retardant comprising hydrotalcite components is obtained.

Inventors

  • GENG CHAO
  • NING ZHANJIN
  • CUI KUNPENG
  • LIN JINLIANG
  • YANG CHUANJIE
  • SUN MAOYU
  • TAO XINYI
  • HAN YUTING

Assignees

  • 中国消防救援学院

Dates

Publication Date
20260505
Application Date
20221202

Claims (7)

  1. 1. The preparation method of the red mud-based nano flame retardant is characterized by comprising the following steps of: mixing red mud and a carbonaceous reducing agent, and carrying out reduction roasting to obtain a roasting product; The red mud comprises 20-50% of Fe 2 O 3 , 30-60% of Al 2 O 3 , 1-10% of MgO and 5-20% of SiO 2 ; Crushing, grinding and magnetically separating the roasting product in sequence to obtain aluminum-rich slag; Mixing the aluminum-rich slag, the magnesium additive and water, and performing mechanochemical reaction in a CO 2 atmosphere to obtain a red mud-based nano flame retardant; The magnesium additive comprises one or more of MgO, mgCO 3 and Mg (OH) 2 , wherein the mass ratio of the magnesium additive to the aluminum-rich slag is (5-10) 100, and the mass ratio of the water to the aluminum-rich slag is (2-8) 100; the mechanochemical reaction is carried out under the condition of ball milling, the rotating speed of the ball milling is 450-600 rpm, and the time of the ball milling is 60-120 min.
  2. 2. The preparation method of the red mud, according to claim 1, is characterized in that the carbonaceous reducing agent comprises one or more of coke, coal and graphite, and the mass ratio of the carbonaceous reducing agent to the red mud is (3-8): 100.
  3. 3. The preparation method according to claim 1, wherein the temperature of the reduction roasting is 1100-1200 ℃ and the time is 30-90 min.
  4. 4. The preparation method according to claim 1, wherein the mass of the ground product which is ground to have the fineness of less than or equal to 0.043mm is 70-80% of the total ground product mass, and the magnetic field strength of the magnetic separation is 800-1200 gs.
  5. 5. The preparation method according to claim 1, wherein the volume concentration of CO2 in the CO 2 atmosphere is 80-100%.
  6. 6. The red mud-based nano flame retardant prepared by the preparation method of any one of claims 1-5, which is characterized in that the red mud-based nano flame retardant comprises magnesium aluminum carbonate hydrotalcite.
  7. 7. The application of the red mud-based nano flame retardant in the flame retardant field.

Description

Red mud-based nano flame retardant, and preparation method and application thereof Technical Field The invention belongs to the technical field of flame retardance, and particularly relates to a red mud-based nano flame retardant, and a preparation method and application thereof. Background The red mud is industrial solid waste discharged after alumina is refined from bauxite, and the byproduct red mud generated by each 1 ton of alumina is 1.0-1.8 tons. A large amount of red mud is piled up, so that not only is the land resource occupied, but also the surrounding environment is seriously affected. At present, the comprehensive recycling method of red mud is more. In the fields of building materials, road construction materials, heat insulation materials and the like, the research on the utilization of red mud has been applied to practice and has achieved a certain effect. However, the comprehensive utilization mode of the red mud also has certain problems, such as the use of the red mud for manufacturing building materials, the existence of radioactive elements in the red mud requires the addition of other substances to reduce the harm of the radioactive elements, the production cost is increased, and the problems of salt permeation and Fan Shuang on the surface of the manufactured building materials after long-time placement can influence the strength and the performance. Therefore, in order to better treat the red mud, a new way for comprehensively recycling the red mud is also required to be studied. Disclosure of Invention In view of the above, the invention aims to provide a red mud-based nano flame retardant, a preparation method and application thereof, the preparation method provided by the invention not only can recover metallic iron from red mud, the red mud can be prepared into the red mud-based nano flame retardant with excellent flame retardant property, so that the efficient resource conversion and utilization of the red mud are realized. In order to achieve the above object, the present invention provides the following technical solutions: the invention provides a preparation method of a red mud-based nano flame retardant, which comprises the following steps: mixing red mud and a carbonaceous reducing agent, and carrying out reduction roasting to obtain a roasting product; Crushing, grinding and magnetically separating the roasting product in sequence to obtain aluminum-rich slag; mixing the aluminum-rich slag, the magnesium additive and water, and performing mechanochemical reaction in a CO 2 atmosphere to obtain the red mud-based nano flame retardant. Preferably, the red mud contains 20-50% of Fe 2O3, 30-60% of Al 2O3, 1-10% of MgO and 5-20% of SiO 2. Preferably, the carbonaceous reducing agent comprises one or more of coke, coal and graphite, and the mass ratio of the carbonaceous reducing agent to the red mud is (3-8) 100. Preferably, the temperature of the reduction roasting is 1100-1200 ℃ and the time is 30-90 min. Preferably, the mass of the ground mineral products which are ground to the fineness of less than or equal to 0.043mm is 70-80% of the total ground mineral substances, and the magnetic field strength of the magnetic separation is 800-1200 GS. Preferably, the magnesium additive comprises one or more of MgO, mgCO 3 and Mg (OH) 2, and the mass ratio of the magnesium additive to the aluminum-rich slag is (5-10): 100. Preferably, the mechanochemical reaction is carried out under the condition of ball milling, the rotating speed of the ball milling is 450-600 rpm, and the time of the ball milling is 60-120 min. Preferably, the volume concentration of CO 2 in the CO 2 atmosphere is 80-100%. The invention also provides the red mud-based nano flame retardant prepared by the preparation method of the technical scheme, and the red mud-based nano flame retardant comprises magnesium aluminum carbonate hydrotalcite. The invention also provides application of the red mud-based nano flame retardant in the flame retardant field. The invention provides a preparation method of a red mud-based nano flame retardant, which comprises the following steps of mixing red mud with a carbonaceous reducing agent, carrying out reduction roasting to obtain a roasting product, sequentially carrying out crushing, ore grinding and magnetic separation on the roasting product to obtain aluminum-rich slag, mixing the aluminum-rich slag, a magnesium additive and water, and carrying out mechanochemical reaction in a CO 2 atmosphere to obtain the red mud-based nano flame retardant. According to the invention, the mechanochemical treatment can lead the surface of the aluminum-rich slag to be exposed with Al 3+, the surface of the magnesium-containing reagent to be exposed with Mg 2+, and then the addition of water and CO 2 is combined to carry out chemical reaction under the action of mechanochemistry to finally generate the magnesium aluminum carbonate hydrotalcite, wherein the preparation process of the magnesium a