CN-121495003-B - Sodium carboxymethyl cellulose, preparation method thereof and dust suppressant

CN121495003BCN 121495003 BCN121495003 BCN 121495003BCN-121495003-B

Abstract

The application belongs to the field of cellulose ether, and provides sodium carboxymethyl cellulose, a preparation method thereof and a dust suppressant. The method comprises the steps of mixing cellulose, solid alkali and a solid etherifying agent to obtain a first mixture, regulating the humidity of the first mixture by using a humidity regulating medium to obtain flowable wet powder, mechanically activating the wet powder to obtain a second mixture, heating the second mixture to enable the second mixture to undergo an alkalization reaction and an etherification reaction, neutralizing the obtained product of the heating treatment to obtain a neutral mixture, and sequentially dissolving and purifying the neutral mixture to obtain sodium carboxymethyl cellulose. According to the method provided by the embodiment of the application, a large amount of organic solvents such as isopropanol and the like are not needed, so that the generation of waste liquid is reduced, and the environmental protection disposal cost and the production safety risk are obviously reduced.

Inventors

XU XIAOCHUAN
LI CHAO
GU XIAOWEI
ZHAO YUNQI
WU ZHIYUAN
ZHONG YUXIANG
Qin Meiman

Assignees

东北大学

Dates

Publication Date: 20260512
Application Date: 20260113

Claims (7)

1. The preparation method of the sodium carboxymethyl cellulose is characterized by comprising the following steps of: Mixing cellulose, a solid base, and a solid etherifying agent to obtain a first mixture; regulating the humidity of the first mixture by using a humidity regulating medium to obtain flowable wet powder, wherein the humidity regulating medium comprises deionized water, and the mass ratio of the humidity regulating medium to the first mixture is (0.08-0.15) to 1; mechanically activating the wet powder to obtain a second mixture; heating the second mixture to enable the second mixture to undergo an alkalization reaction and an etherification reaction; neutralizing the heated product to obtain a neutral mixture; Sequentially carrying out dissolution treatment and purification treatment on the neutral mixture to obtain sodium carboxymethyl cellulose; The dissolution treatment includes mixing the neutral mixture with water to obtain a mixed solution; the purification treatment process comprises the steps of carrying out microfiltration on the mixed solution to obtain filtrate, and supplementing fresh water as first dialysis water in the microfiltration process; ultrafiltering the filtrate to obtain a retentate, and supplementing fresh water as second permeate during the ultrafiltration.
2. The method of claim 1, wherein the solid base comprises at least one of sodium hydroxide, potassium hydroxide, calcium hydroxide, sodium carbonate; The solid etherifying agent comprises at least one of sodium monochloroacetate, potassium monochloroacetate, methyl chloroacetate and ethyl chloroacetate; In the first mixture, the mass ratio of the cellulose to the alkali to the etherifying agent is 1: (0.30-0.40): (0.80-1.00).
3. The method according to claim 1, wherein the temperature of the heat treatment is 50 ℃ to 70 ℃, and the time of the heat treatment is 1.5h to 4h.
4. The method according to claim 1, wherein the neutralization treatment comprises introducing carbon dioxide or an atomized acid solution into the heat-treated product; the acid solution comprises at least one of acetic acid solution, citric acid solution, lactic acid solution and carbonic acid solution.
5. The method according to claim 1, wherein, In the mixed solution, the concentration of sodium carboxymethyl cellulose is 3-8 wt%.
6. The method according to claim 5, wherein, Concentrating the trapped fluid to obtain concentrated fluid; drying the concentrated solution to obtain sodium carboxymethyl cellulose.
7. The method according to claim 6, wherein the microfiltration is a ceramic membrane filtration, the pressure of the microfiltration is 0.1MPa to 0.5MPa, and the pore diameter of the ceramic membrane is 20nm to 100nm; the ultrafiltration is organic membrane filtration, the pressure of the ultrafiltration is 1MPa-3MPa, and the molecular weight cut-off of the organic membrane is 2kDa-10kDa.

Description

Sodium carboxymethyl cellulose, preparation method thereof and dust suppressant Technical Field The application relates to the technical field of cellulose ether, in particular to sodium carboxymethyl cellulose, a preparation method thereof and a dust suppressant. Background The particle size of the dust particles in the dry beach area of the iron tailings is mainly distributed at 1-100 mu m, and flotation reagent residues and partial heavy metal ions are attached to the surfaces of the particles, so that the specific surface area of the dust particles is large, the surface energy is high, and the dust particles are easily disturbed by wind fields to suspend in the air. At present, a composite dust suppressant consisting of sodium carboxymethyl cellulose, polyacrylamide, glycerol and the like is mainly used for treating dust particles. The sodium carboxymethyl cellulose is used as a key bonding component, and a large amount of organic solvent is used in the existing preparation method, so that more waste liquid is generated, the subsequent cost for treating the waste liquid is obviously increased, and the requirements of greenization and large-scale application are difficult to meet. It should be noted that the foregoing is not necessarily prior art, and is not intended to limit the scope of the present application. Disclosure of Invention The embodiment of the application provides sodium carboxymethyl cellulose, a preparation method thereof and a dust suppressant, which are used for solving or relieving one or more of the technical problems. In a first aspect of the embodiment of the present application, a preparation method of sodium carboxymethylcellulose is provided, including the following steps: Mixing cellulose, a solid base, and a solid etherifying agent to obtain a first mixture; adjusting the humidity of the first mixture by using a humidity adjusting medium to obtain flowable wet powder; mechanically activating the wet powder to obtain a second mixture; heating the second mixture to enable the second mixture to undergo an alkalization reaction and an etherification reaction; neutralizing the heated product to obtain a neutral mixture; And sequentially carrying out dissolution treatment and purification treatment on the neutral mixture to obtain sodium carboxymethyl cellulose. The method comprises the steps of firstly mixing cellulose, solid alkali and a solid etherifying agent in a solid form to obtain a first mixture, then adding a small amount of humidity-adjusting medium to maintain the humidity of the first mixture to obtain flowable wet powder, then promoting alkali to be uniformly dispersed and transferred into the cellulose in a mechanical activation mode to obtain a second mixture, carrying out alkalization reaction and etherification reaction on the second mixture under a heating condition to obtain a reaction material containing sodium carboxymethyl cellulose and byproduct salt, and then carrying out neutralization treatment, dissolution treatment and purification treatment on the obtained product after the heating treatment to obtain sodium carboxymethyl cellulose. In this way, sodium carboxymethyl cellulose is prepared by adopting a solid mixing-humidifying-reacting (alkalizing reaction and etherification reaction) route based on solid alkali and solid etherifying agent, and the process does not need to adopt a large amount of organic solvents such as isopropanol and the like, and only needs to carry out limited dissolution and purification on the neutral mixture, thereby reducing the production of waste liquid, and obviously reducing the environmental protection disposal cost and the production safety risk. In addition, the method of the application can also omit complex unit operations such as solvent recovery, rectification, repeated washing and the like in the traditional process. In a word, the process flow of the method is obviously shortened, the equipment investment and the operation energy consumption (especially the heat energy consumption) are greatly reduced, and the method meets the requirements of green chemistry and clean production. According to an embodiment of the application, the solid alkali comprises at least one of sodium hydroxide, potassium hydroxide, calcium hydroxide and sodium carbonate, the solid etherifying agent comprises at least one of sodium monochloroacetate, potassium monochloroacetate, methyl chloroacetate and ethyl chloroacetate, and the mass ratio of the cellulose to the alkali to the etherifying agent in the first mixture is 1:0.30-0.40:0.80-1.00. Thus, the three components of cellulose, alkali and etherifying agent can fully perform the alkalization reaction and the etherification reaction. According to the embodiment of the application, the humidity-adjusting medium comprises at least one of deionized water, ethanol and isopropanol, and the mass ratio of the humidity-adjusting medium to the first mixture is 1: (0.08-0.15). Thereby, it is ensure