阅读说明：本技术 一种尾矿砂充填胶凝辅助材料及其制备方法 (Tailing sand filling cementing auxiliary material and preparation method thereof ) 是由 张建俊 姚柏聪 孙闯 陈东旭 金淳哲 王洋 于 2021-09-22 设计创作，主要内容包括：本发明公开了一种尾矿砂充填胶凝辅助材料及其制备方法,其主要成分包括：磺化油4～50份、硅烷类偶联剂30～35份、阴离子聚丙烯酰胺8～10份、碱性激发剂6～10份、环保硫酸盐激发剂3～5份、分散剂0.3～0.8份、阴离子型表面活性剂1～2份、水100份；本发明所述尾矿砂充填胶凝辅助材料,以小剂量辅助污泥、水渣、钢渣、脱硫灰、粉煤灰等固体废弃物胶凝尾矿砂,即可使充填料浆强度达到预期目标；辅助水泥胶凝尾矿砂进行充填时,宜可有效降低灰砂比,节约生产成本,掺有充填胶凝辅助材料的充填体,具有更高的强度与更好的耐久性。本发明所述尾矿砂充填胶凝辅助材料,生产成本低、胶凝效果优良、材料安全环保、制备工艺简单,为一种新型绿色环保胶凝材料,应用前景广阔。(The invention discloses a tailing sand filling cementing auxiliary material and a preparation method thereof, and the tailing sand filling cementing auxiliary material mainly comprises the following components: 4-50 parts of sulfonated oil, 30-35 parts of silane coupling agent, 8-10 parts of anionic polyacrylamide, 6-10 parts of alkaline activator, 3-5 parts of environment-friendly sulfate activator, 0.3-0.8 part of dispersant, 1-2 parts of anionic surfactant and 100 parts of water; according to the invention, the tailing sand filling gelling auxiliary material is used for assisting solid wastes such as sludge, water granulated slag, steel slag, desulfurized ash and fly ash to gel the tailing sand in a small dosage, so that the strength of filling slurry can reach an expected target; when the auxiliary cement gelling tailing sand is filled, the ash-sand ratio can be effectively reduced, the production cost is saved, and the filling body doped with the auxiliary filling gelling material has higher strength and better durability. The tailing sand filling cementing auxiliary material has the advantages of low production cost, excellent cementing effect, safe and environment-friendly material, simple preparation process, wide application prospect, and is a novel environment-friendly cementing material.)

1. The tailing sand filling cementing auxiliary material is characterized by comprising the following components in parts by mass:

45-50 parts of sulfonated oil, 30-35 parts of silane coupling agent, 8-10 parts of anionic polyacrylamide, 6-10 parts of alkaline activator, 3-5 parts of environment-friendly sulfate activator, 0.3-0.8 part of dispersant, 1-2 parts of anionic surfactant and 100 parts of water.

The preparation method of the tailing sand filling cementing auxiliary material comprises the following specific steps:

step one, pouring the alkaline activator and the environment-friendly sulfate activator into a stirrer at the same time, uniformly stirring, and carrying out stirring indoors or ensuring that the stirring environment maintains indoor temperature and humidity, wherein the stirring speed is 100r/min, and the stirring time is 2-5 min.

And step two, pouring the water and the anionic surfactant in parts into a stirrer for mixing, uniformly stirring, and carrying out stirring indoors or ensuring that the indoor temperature and humidity are maintained in a stirring environment, wherein the stirring speed is 150r/min, and the stirring time is 2-5 min.

And step three, sequentially putting the silane coupling agent, the sulfonated oil, the anionic polyacrylamide and the dispersing agent in parts into a stirrer for mixing, uniformly stirring, and carrying out indoor stirring or ensuring that the indoor temperature and humidity are maintained in a stirring environment, wherein the stirring speed is 300r/min, and the stirring time is 10-15 min, so as to obtain the tailing sand filling cementing auxiliary material.

2. The tailings sand packing cementitious auxiliary material of claim 1, wherein the sulfonated oil is an anionic surfactant.

3. The tailing sand filling cementitious auxiliary material according to claim 1, wherein the alkali-activator is one of calcium hydroxide and sodium silicate.

4. The tailing sand filling cementitious auxiliary material of claim 1, wherein the environmentally friendly sulfate excitant is one of sodium sulfate, calcium sulfate and phosphogypsum.

5. The tailing sand-filled supplementary cementitious material as claimed in claim 1, wherein the dispersant is one of fatty acids, paraffins and metal soaps.

6. The tailing sand filling cementitious auxiliary material of claim 1, wherein the anionic surfactant is one of sodium alkyl sulfonate and sodium alkyl sulfate.

Technical Field

The invention relates to the technical field of solid waste treatment, in particular to a tailing sand filling cementing auxiliary material and a preparation method thereof.

Background

The tailings are the largest industrial solid waste in China, occupy a large amount of land resources such as agriculture and forestry, seriously pollute the surrounding ecological environment and are easy to cause geological disasters. The main treatment mode at the present stage is to take the tailings as the main raw material for filling, so that the utilization rate of solid wastes is improved, but the comprehensive utilization rate is not high, and the main reasons are as follows: the tailing sand is used as a filling body of main aggregate, the strength is low, the impermeability is poor, the durability is poor, the strength requirement can be met only by mixing a large amount of traditional cementing materials such as cement, and the treatment cost is high, so the tailing sand cementing auxiliary material is generated.

The traditional cementing auxiliary material on the market is a soil curing agent, is a novel energy-saving environment-friendly engineering material synthesized by multiple inorganic and organic materials and used for curing various soils, and has the characteristics of small using amount, remarkable curing effect, convenient construction in engineering application and the like, but most of the applicable objects of the traditional cementing auxiliary material at the present stage are soil bodies, the cementing auxiliary material used for filling tailing sand is fresh, the traditional cementing auxiliary material can only be used for assisting the conventional cementing materials such as cement and the like in use, and when small dose of auxiliary solid wastes such as sludge, water slag, steel slag, desulfurized ash, fly ash and the like are used for cementing the tailing sand, the curing effect is poor, the filling slurry strength is low and the like.

Disclosure of Invention

A first object of the present invention is to solve at least the above problems and to provide at least the advantages which will be described later.

The invention also provides a tailing sand filling cementing auxiliary material and a preparation method thereof. The tailing sand filling cementing auxiliary material has the characteristics of low blending usage amount, low production cost, excellent curing effect, simple preparation process, safety, greenness, environmental protection and the like.

In order to achieve the purpose and other advantages, the invention provides a tailing sand filling cementing auxiliary material which comprises the following components in parts by weight:

45-50 parts of sulfonated oil, 30-5 parts of silane coupling agent, 8-10 parts of anionic polyacrylamide, 6-10 parts of alkaline activator, 3-5 parts of environment-friendly sulfate activator, 0.3-0.8 part of dispersant, 1-2 parts of anionic surfactant and 100 parts of water.

Preferably, the alkali-activator is Ca (OH)₂。

Preferably, the environment-friendly sulfate excitant is CaSO₄。

Preferably, the dispersant is a paraffin.

The preparation method of the tailing sand filling cementing auxiliary material comprises the following specific steps:

step one, pouring the alkaline activator and the environment-friendly sulfate activator into a stirrer at the same time, uniformly stirring, and carrying out stirring indoors or ensuring that the stirring environment maintains indoor temperature and humidity, wherein the stirring speed is 100r/min, and the stirring time is 2-5 min.

And step two, pouring the water and the anionic surfactant in parts into a stirrer for mixing, uniformly stirring, and carrying out stirring indoors or ensuring that the indoor temperature and humidity are maintained in a stirring environment, wherein the stirring speed is 150r/min, and the stirring time is 2-5 min.

And step three, sequentially putting the silane coupling agent, the sulfonated oil, the anionic polyacrylamide and the dispersing agent in parts into a stirrer for mixing, uniformly stirring, and carrying out indoor stirring or ensuring that the indoor temperature and humidity are maintained in a stirring environment, wherein the stirring speed is 300r/min, and the stirring time is 10-15 min, so as to obtain the tailing sand filling cementing auxiliary material.

The invention at least comprises the following beneficial effects:

the tailing sand filling cementing auxiliary material is a green environment-friendly material with a simple preparation process, and can meet the strength requirement when tailing sand is used as a main aggregate, sludge, desulfurized ash, water slag powder, steel slag powder, fly ash and other solid wastes are used as a filling body of the cementing material, and a small amount of tailing sand is mixed to fill the cementing auxiliary material; when the tailing sand filling body taking cement as a main cementing material is mixed with a small amount of tailing sand to fill the cementing auxiliary material, the cement consumption can be reduced, the production cost is saved, and the cemented tailing sand filling material has higher compressive strength and tensile strength in the early stage and the final stage, and has good impermeability and durability;

secondly, the added sulfonated oil (anionic surfactant) is one of the components, namely n-butyl oleate sodium sulfate, the molecular weight is high, the molecular structure has two functional groups with opposite hydrophilic performance and negative charges, and one end functional group in the molecule is formed by RSO₃H, and the other end of the hydrophilic end is a hydrophobic end with a functional group consisting of C, H atoms, when the sulfonated oil is added into the tailings, the water content in the tailings is reduced, the sulfonated oil and the tailings particles are solidified, and the solidification is irreversible and permanent. The reasons for the gelation are mainly that one end of the sulfonated oil is hydrophilic and the most Al in the tailing sand is in the hydrophilic end³⁺、Mg²⁺、Fe³⁺When cations are combined with each other, a new ionic bond is generated, the gelling force among tailing sand particles is increased, the hydrophobic end at the other end of the sulfonated oil is wrapped on the surface of the tailing sand to form a hydrophobic film, and the hydrophobicity of the tailing sand is converted into hydrophobicity;

thirdly, the general formula of the added silane coupling agent is RSiX₃According to the characteristics of the molecular structure general formula, X is a hydrolyzable group and can chemically react with the surface of the tailing sand. The coupling agent is melted into water to generate hydrolysis reaction to generate monomer and oligomer, wherein Si-OH groups generated by hydrolysis are combined with-OH groups on the surface of the tailing sand to form hydrogen bonds, and the monomer and the oligomer are subjected to dehydration condensation reaction in a dry environment to form stable Si-O-Si covalent bonds and generate permanent solidification on the tailing sand;

fourthly, the added anionic polyacrylamide is absorbed on the surface to form a film by combining anions with a large number of cations on the surface of the tailing sand, so that the tailing sand forms micro aggregates, the physical structure of the tailing sand is improved, and the cohesive force among tailing sand particles is increased;

fifth, Ca (OH) is added₂(alkali activator), CaSO₄(sulfate excitant) to prepare a mixed excitant, and the activity of the traditional cement cementing material, sludge, desulfurized ash, water slag powder, steel slag powder, fly ash solid waste cementing material and tailing sand filled with main aggregate is stimulated to increase the strength of the tailing sand. By carrying out XRF and XRD detection on the tailing sand filled with the main aggregate and the cementing material,as can be seen from tables 1-1, 1-2 and FIG. 1, the cement and the tailings are complex in composition and contain a large amount of SiO₂、Al₂O₃CaO, metal cations and the like, and when the tailing sand cementing auxiliary material is added and fully stirred, the early slaked lime and a large amount of ionic Al in the tailing sand³⁺、Mg²⁺、Fe³⁺And SO₄ ^2-Plasma reaction is carried out to form compact cementing materials such as C-S-H bonds and AFt phase ettringite, pores among the tailing sands are filled, the bonding effect and early strength among the tailing sands are improved, the hydrophilicity of the tailing sands is reduced, and in the later period, when gypsum completely participates in hydration, the ettringite is converted into an AFm phase, and the final strength is improved;

TABLE 1-1 XRF chemical composition analysis results of tailings sands

FeO	SiO2	Al2O3	Fe2O3	CaO	MgO	MnO	P2O5	TiO2	K2O	Na2O	S
												9.96	71.73	1.77	3.37	2.51	7.05	0.21	0.17	0.047	0.34	0.19	0.096

Table 1-2 gel material XRF chemical composition analysis results

6, the added anionic surfactant is hydrophobic anions when dissolved in water, and has the functions of increasing the solubility of an alkaline activator and a sulfate activator in water, exciting active substances on the surface of the tailing sand particles and adsorbing metal cations on the surface of the tailing sand particles and having a certain water blocking effect;

7, the added dispersant has lipophilicity and hydrophily, can disperse oily substances in the gelling auxiliary raw material and prevent the coagulation of the alkaline activator and the sulfate activator in water.

Drawings

FIG. 1 shows XRD diffraction patterns of tailings sand and cementitious material;

FIG. 2 is a graph showing the comparison of the compressive strengths of S-1, S-2 and D-1 at different curing ages;

FIG. 3 is a graph showing the comparison of the compressive strengths of S-1, S-2 and D-1 at different curing ages;

FIG. 4 shows SEM images of the microstructures of S-1 and D-1 tailings sand pack;

FIG. 5 shows the form distribution fractal drawing of the pore unit of S-1 and D-1 tailing sand filling bodies.

Detailed Description

The embodiments of the present invention will be described more fully hereinafter with reference to the accompanying drawings, in which some, but not all embodiments of the invention are shown. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example one

The method is characterized in that the tailing sand is used as aggregate, the cementing material is a conventional common cementing material, the national standard P.O 42.5.5 cement is prepared, the ash-sand ratio is 1:4, the slurry concentration is 70%, and the addition amount of the tailing sand filling cementing auxiliary material is the total massThe cement tailing sand filler (hereinafter referred to as S-1). The auxiliary gelling material comprises the following components in parts by weight: 47 parts of sulfonated oil, 35 parts of KH550 silane coupling agent, 10 parts of anionic polyacrylamide, Ca (OH)₂8 portions of CaSO₄5 parts of white oil, 0.5 part of sodium alkyl sulfonate and 100 parts of water.

Example two

The preparation method is characterized in that the tailing sand is used as aggregate, the cementing material is solid waste desulfurized ash and blast furnace water granulated slag which are mixed according to the proportion of 1:3, the ash-sand ratio is 1:4, the slurry concentration is 70%, and the addition amount of the tailing sand filling cementing auxiliary material is the total massThe slag powder tailing sand filler (hereinafter referred to as S-2). The auxiliary gelling material comprises the following components in parts by weight: sulfonation of47 parts of oil, 35 parts of KH550 silane coupling agent, 10 parts of anionic polyacrylamide, Ca (OH)₂8 portions of CaSO₄5 parts of white oil, 0.5 part of sodium alkyl sulfonate and 100 parts of water.

The concrete method of the auxiliary gelling material comprises the following steps:

step one, mixing the Ca (OH) of the parts₂、CaSO₄And meanwhile, pouring the mixture into a stirrer for mixing, uniformly stirring, and stirring at the speed of 100r/min for 2-5 min indoors or under the condition that the indoor temperature and humidity are maintained in a stirring environment.

And step two, pouring the water and the sodium alkylsulfonate into a stirrer to be mixed, uniformly stirring, and carrying out stirring indoors or ensuring that the indoor temperature and humidity are maintained in a stirring environment, wherein the stirring speed is 150r/min, and the stirring time is 2-5 min.

And step three, sequentially putting the KH550 silane coupling agent, the sulfonated oil, the anionic polyacrylamide and the white oil in parts into a stirrer for mixing, uniformly stirring, carrying out indoor stirring or ensuring that the indoor temperature and humidity are maintained in a stirring environment, wherein the stirring speed is 300r/min, the stirring time is 10-15 min, and the preparation of the tailing sand filling gelling auxiliary material is completed.

Comparative example 1

The cement tailing sand filling body (D-1) is prepared by taking tailing sand as an aggregate, taking a cementing material as a common cementing material, taking the cementing material as national standard P.O42.5 cement, setting the ash-sand ratio to be 1:4 and the slurry concentration to be 70% and not adding tailing sand filling cementing auxiliary materials.

The specific test method comprises the following steps:

the test pieces prepared in the first embodiment, the second embodiment and the first embodiment are put into a curing box, cured to corresponding age, and subjected to performance test:

firstly, detecting the compressive strength performance:

the test pieces of 70.7X 70.7cm prepared in the first examples, the second examples and the first comparative examples were put into a curing box of type YH-90B, cured for 3d, cured for 7d and cured for 28d, and the compressive strength was measured.

TABLE 2 compressive strengths at different curing ages

	3d compressive Strength (MPa)	7d compressive Strength (MPa)	28d compressive Strength (MPa)
				EXAMPLE one (S-1)	1.01	1.75	4.43
EXAMPLE two (S-2)	0.70	1.18	3.31
				COMPARATIVE EXAMPLE I (D-1)	0.79	1.09	3.27

As can be seen from the results of Table 2 and S-1 and S-2 in FIG. 2, the auxiliary cementitious material has a good cementitious effect on the tailings sand, and the 3D, 7D and 28D strengths all meet the requirements of the complete tailings paste filling technical Specification (GB/T39489-. Comparing S-2 with D-1, it can be seen that the compressive strength of example two 3D is less than that of comparative example one, while the compressive strengths of examples two 7D and 28D are both greater than that of comparative example one, and the early and final compressive strengths of S-2 are similar to or even greater than that of D-1, indicating that the new method of using the auxiliary cementitious material to solidify solid waste as the cementitious material for the tailing fill is feasible.

Secondly, detecting tensile strength performance:

the tensile strength of the test pieces of 70.7X 70.7cm prepared in examples one, two and comparative example one was measured by placing them in a curing box of type YH-90B and curing for 3d, 7d and 28 d.

TABLE 3 tensile strength at different curing ages

	3d tensile Strength (MPa)	7d tensile Strength (MPa)	28d tensile Strength (MPa)
				EXAMPLE one (S-1)	0.14	0.25	0.60
EXAMPLE two (S-2)	0.10	0.18	0.47
				COMPARATIVE EXAMPLE I (D-1)	0.09	0.14	0.38

As can be seen from Table 3, the early and final tensile strengths of S-1 and S-2 are higher than that of D-1, indicating that the increase of the tensile strength of the tailing sand filling body after the cementitious auxiliary material is cured is obvious. As can be seen from the comparison of S-1 and S-2 in FIG. 3, the strength effect of the gelled auxiliary material on the solidified slag powder tailings is more significant than that of the gelled auxiliary material on the tensile strength.

Comprehensive test data show that the compressive strength and the tensile strength of the tailing sand filling body after the auxiliary cementing material is solidified are obviously improved, the auxiliary cementing material has obvious solidification effects on the cement tailing sand filling body and the slag powder tailing sand filling body, and a new method is provided for comprehensively utilizing solid wastes and preparing the cementing material.

Thirdly, detecting the impermeability:

the first, second and first comparative examples were prepared into truncated cone-shaped test pieces with an upper mouth diameter of 70mm, a lower mouth diameter of 80mm and a height of 30mm, and cured in a YH-90B type standard constant temperature and humidity curing box for 28d, and the test procedure was carried out according to "basic performance test method for building mortar" (JGJ 70-2009) to determine the impermeability rating of the tailing sand fillers of the first, second and first comparative examples, respectively.

TABLE 4 impermeability grade

	EXAMPLE one (S-1)	EXAMPLE two (S-2)	COMPARATIVE EXAMPLE I (D-1)
				Grade of impermeability	P6	P6	P5

According to the specification of concrete quality control Standard (GB 50164-2011), the material with the impermeability grade being more than or equal to P6 has impermeability, and the analysis table 4 shows that S-1 and S-2 tailing sand filling bodies added with the cementing auxiliary material both meet the impermeability requirement, but do not meet the impermeability requirement for the D-1 tailing sand filling body.

The impermeability of the material is mainly related to the pores of the material, the impermeability grade is high, the porosity of the material is low, the material shows that the tailing sand solidified by the tailing sand gelling auxiliary material forms a compact structure, the pores among tailing sand particles are reduced, the effect of converting the hydrophilicity of the solidified tailing sand into the hydrophobicity is obvious, and the material has high impermeability.

Fourthly, microstructure analysis:

processing SEM images of microstructures of S-1 and D-1 tailing sand fillers by utilizing IPP6.0, extracting equivalent areas and equivalent circumferences of microscopic pores as shown in figure 3, drawing a double-log diagram of the equivalent areas and the equivalent circumferences as shown in figure 4, calculating a pore distribution fractal dimension of the fillers according to (1), and analyzing microstructure changes of the fillers before and after adding the auxiliary gelling material.

In the formula: p is the equivalent pore perimeter; a is the equivalent area of the pore; d is a pore form distribution fractal dimension; c is a constant.

As can be seen from FIG. 4, the pore distribution fractal dimension of the cement tailing sand filling body with the cementing auxiliary material added in the S-1 state is 1.6264, the pore distribution fractal dimension of the cement tailing sand filling body with the D-1 state without the cementing auxiliary material added in the D-1 state is 1.7034, the size of the fractal dimension represents the complexity of the microscopic pore distribution, and the more disordered the pore distribution, the larger the fractal dimension. In the first example after the addition of the auxiliary gelling material, the fractal dimension of the pore distribution was reduced by 0.077, which indicates that the grains of the tailing sand filling body after the addition of the auxiliary gelling material become orderly arranged. The porosity can be greatly reduced, the distance between tailing sand particles is reduced, and the structure of the filling body is more compact and compact.