CN-121991379-A - Preparation method of bio-based interpenetrating network hydrogel and application of solidified fine tailings

CN121991379ACN 121991379 ACN121991379 ACN 121991379ACN-121991379-A

Abstract

A preparation method of a bio-based interpenetrating network hydrogel and application of solidified fine tailings comprise the following steps of S1, adding CMC (carboxymethyl cellulose) and HEC (hydroxyethyl cellulose) into a three-neck flask filled with deionized water according to a mass ratio of (3:1) - (5:4), dissolving the CMC and HEC into the deionized water, and dissolving the CMC and HEC into the deionized water under magnetic stirring at 40-50 ℃ and 300rpm to form a transparent homogeneous solution, S2, introducing nitrogen into the solution obtained in the step S1 for 30min, and then sequentially adding APS (ammonium persulfate) and MBA (methylene bisacrylamide), wherein APS is an initiator, and MBA is a cross-linking agent. The CMC-HEC interpenetrating network hydrogel acts on tailings through a triple mechanism of physical wrapping-functional group complexing-interpenetrating network synergy, wherein carboxyl groups of CMC form a rigid framework with tailings particles and heavy metal ions through ionic bonding, and hydroxyethyl chains of HEC fill pores through hydrogen bonding to form a flexible network, so that the two form an interpenetrating network through MBA crosslinking, and the reinforcing effect of 'hardness and softness and economy' is realized.

Inventors

DU CHANGBO
LI FENG
WANG HAOWEN
YI FU
NIU BEN
SUN QI
LI XILIN
JIANG LIGUO
LV HUIXIN

Assignees

辽宁工程技术大学

Dates

Publication Date: 20260508
Application Date: 20260127

Claims (10)

1. The preparation method of the bio-based interpenetrating network hydrogel is characterized by comprising the following steps of: S1, adding CMC and HEC into deionized water, and dissolving under the condition of stirring to obtain transparent homogeneous solution; S2, introducing nitrogen, and adding an initiator and a crosslinking agent; s3, subsequently heating the solution in the step S2, and continuously stirring to perform graft copolymerization reaction until the solution viscosity is observed to be obviously increased and elastic gel is formed, so as to form crude gel; and S4, after the reaction liquid is cooled to room temperature, transferring the crude gel into a beaker, adding absolute ethyl alcohol into the beaker for continuous soaking to remove unreacted monomers, and then placing the crude gel into a vacuum drying oven for drying to constant weight, thus obtaining the white hydrogel powder.
2. The preparation method of the bio-based interpenetrating network hydrogel according to claim 1, wherein the mass ratio of CMC to HEC in the step S1 is (3:1) - (5:4), the stirring temperature in the step S1 is 40-50 ℃, and the stirring speed is 300rpm; the nitrogen gas is introduced in the step S2 for 30min, the initiator is ammonium persulfate APS, and the cross-linking agent is methylene bisacrylamide MBA.
3. The preparation method of the bio-based interpenetrating network hydrogel according to claim 1, wherein the solution heating temperature in the step S3 is 70-80 ℃, and the continuous stirring time in the step S3 is 40-60 min; The absolute ethanol content added in the step S4 is 200mL, the soaking time is 12h, and the temperature of the vacuum drying oven in the step S4 is 60 ℃.
4. The method of preparing a bio-based interpenetrating network hydrogel according to claim 1, wherein the optimal mass ratio of CMC to HEC in the step S1 is 5:4, the addition amount of CMC is 5g, the addition amount of HEC is 4g, the addition amount of APS is 0.01g, and the addition amount of MBA is 0.4g.
5. A biobased interpenetrating network hydrogel, characterized by being obtained by the preparation method according to any one of claims 1-4.
6. The application of the biobased interpenetrating network hydrogel in curing fine tailings, which is characterized in that the high-efficiency green curing of the fine tailings is realized, and the mechanical strength, the heavy metal fixing capability and the environmental sustainability are synchronously improved.
7. The use of the biobased interpenetrating network hydrogel according to claim 6 for solidifying fine tailings, wherein said fine tailings are graphite tailings.
8. A method of solidifying fine tailings using the biobased interpenetrating network hydrogel of claim 5, comprising the steps of: Step A, mixing the hydrogel powder and the fine tailings by adopting a dry mixing method, wherein the hydrogel powder and the fine tailings are uniformly dispersed on the surfaces of the tailings particles during mixing; step B, filling the mixed materials into a mould in 5 layers, wherein the filling amount of each layer is 1/5 of the total mass; Step C, uniformly compacting each layer of die for 25 times or 30 times by using a standard compaction hammer, lightly scratching the surface layer by using a scraper after each layer is compacted, enhancing the bonding force between layers, and avoiding the delamination interface to be a weak area; d, after the pressure equalization of all the 5 layers of dies in the step B is completed, standing for 10min to release internal stress, and then slowly demoulding; And E, placing the demoulded test piece into a drying box, drying at 105 ℃ for 48 hours, taking out, and then carrying out flattening treatment on the surface of the test piece to finally obtain the solidified fine tailings.
9. The method for solidifying fine tailings with a hydrogel according to claim 8, wherein the hydrogel is added in an amount of 0.5-3% of the dry mass of the tailings.
10. The method for solidifying fine tailings with a hydrogel according to claim 8, wherein the hydrogel is added in an amount of 1.0-2.0% of the dry mass of the tailings.

Description

Preparation method of bio-based interpenetrating network hydrogel and application of solidified fine tailings Technical Field The invention relates to the technical field of hydrogel preparation and fine tailings application, in particular to a preparation method of a bio-based interpenetrating network hydrogel and application of solidified fine tailings. Background Under the background of continuous improvement of the development intensity of the global mineral resources and the refined development of the mineral separation process, the yield of the fine tailings (the grain diameter is more less than 0.075 mm, the specific surface area is large and the mud content is high) discharged by various ferrous metal, nonferrous metal and nonmetal mines is continuously increased. The fine tailings are usually conveyed to a tailings pond or a storage site in a slurry form with high water content, and a large amount of the fine tailings are stored for a long time, so that not only are land resources occupied and the layout of mining areas and surrounding land is affected, but also the environmental risk is obviously increased due to the characteristics of ultra-fine particles, high surface activity, carrying beneficiation agents and the like. In the existing engineering, the mode of hydraulic conveying to a tailing dam enclosing sedimentation tank for natural sedimentation is often adopted for disposal, but the mode has double hidden troubles that on one hand, the construction and maintenance cost of the tailing pond is high and the occupied area is large, on the other hand, the residual flotation agents (such as collectors, foaming agents, inhibitors and the like) and the existing heavy metals in the tailings are easy to migrate into a soil-groundwater system under the long-term permeation and leaching effects, so that the organic matter content of polluted soil is reduced, the aggregate structure is damaged, the biotoxicity is accumulated, and the ecological safety and the agricultural sustainable utilization of the area are seriously threatened. At present, the conventional treatment of the fine tailings is mainly carried out by piling up the tailings by a tailings dam, and the research on recycling is mainly focused on two major directions of building material recycling and solidification/stabilization treatment. In the aspect of building material utilization, attempts are made to mix fine tailings into cement products, sintered or baking-free bricks, ceramic materials, asphalt mixtures and the like, but the problems of uneven grain size distribution, high proportion of argillaceous particles, high porosity, insufficient early strength of a solidified body or a product, high dry shrinkage cracking sensitivity, increased consumption of cementing materials for meeting strength requirements, easy induction of brittleness enhancement, durability reduction and the like are caused. In the solidification/stabilization aspect, cement and a base composite curing agent thereof are mainly used, mechanical properties are improved and heavy metals are fixed through filling and wrapping of hydration products, but the defects that firstly, the energy consumption is high, the carbon emission is large in the cement clinker preparation process, contradiction exists with the current double-carbon targets, secondly, the cement hydration products are easy to decompose and erode under the environments of acid rain, acid percolate and the like, the solidified heavy metals can be released again, secondary pollution risks exist, thirdly, the surfaces of fine tailings are often negatively charged or adsorbed with organic medicament films, the compatibility of the cement hydration products and interfaces is poor, the interfaces are easy to form weak bonding layers, and the strength exertion and long-term stability of the solidified bodies are limited. Therefore, the existing fine tailings disposal and resource utilization technologies are still difficult to meet engineering requirements in terms of mechanical reinforcement, long-term stable fixation of heavy metals and environmental friendliness, and development of a novel curing material which is wide in source, low in carbon and environment-friendly and good in compatibility with fine tailings interfaces and an application method thereof are needed. Based on the method, the invention provides a preparation method of a bio-based interpenetrating network hydrogel and application of the bio-based interpenetrating network hydrogel in fine tailings solidification. Disclosure of Invention The invention aims to provide a preparation method of a bio-based interpenetrating network hydrogel and application of cured fine tailings, which are used for solving the problems that the particle size of the fine tailings is small, the specific surface area is large, the porosity is high, the strength and durability of a cured body are difficult to improve under the condition of low doping amount of the exi