Seawater-mixed high-pressure salt corrosion-resistant all-solid-waste anti-seepage grouting material and preparation method thereof

Abstract

The invention discloses a seawater-mixed high-pressure salt corrosion-resistant all-solid-waste anti-seepage grouting material and a preparation method thereof. The high-pressure salt corrosion-resistant all-solid-waste anti-seepage grouting material can adapt to a high-salt and high-pressure environment. In addition, the adopted raw materials are almost zero in cost, solid raw materials are all taken from solid wastes, and solid waste recycling is achieved; strong alkaline leachate of an alkaline residue field is used as an alkali activator, and waste is treated by waste; finally, seawater is adopted for mixing according to local conditions, so that fresh water resources are greatly saved, and the anti-seepage performance can be improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of cement paste compositions, and particularly relates to a seawater-mixed high-pressure salt corrosion-resistant full-solid-waste anti-seepage grouting material and a preparation method thereof. BACKGROUND

[0002] With the rapid development of underground engineering construction, the problem of anti-seepage and leakage in underground engineering is increasingly prominent. Groundwater is rich in various salt ions, especially chloride ions and sulfate ions, which have a significant erosion effect on traditional cement-based grouting materials, resulting in a decrease in material strength and insufficient durability. In coastal underground engineering, high water pressure and strong ion corrosion (among which magnesium ions, chloride ions and sulfate ions are typical groundwater corrosive ions) often act together, exacerbating the long-term safety and stability of underground engineering. At present, commonly used cement paste consumes a large amount of resources and produces high carbon emissions, and does not have salt corrosion resistance and high-pressure permeation resistance, making it difficult to meet the long-term anti-seepage requirements under complex geological conditions.

[0003] Essentially, municipal bulk solid waste has become a serious challenge to the sustainable development of the country, and it is urgent to prepare new environmentally friendly grouting materials in combination with the characteristics of different solid wastes and the characteristics of regional solid waste utilization. SUMMARY

[0004] The purpose of the present application is to provide a seawater-mixed high-pressure salt corrosion-resistant full-solid-waste anti-seepage grouting material that can adapt to high-salt high-pressure environments and realize solid waste resource utilization.

[0005] Correspondingly, the application also provides a preparation method of a seawater-mixed high-pressure salt corrosion-resistant full-solid-waste anti-seepage grouting material.

[0006] The technical solution of the present application is as follows:

[0007] A seawater-mixed high-pressure salt corrosion-resistant full-solid-waste anti-seepage grouting material is obtained by mixing a solid waste main material with seawater;

[0008] The solid waste main material is composed of 30-50wt% of activated lead-zinc tailings slag, 30-48wt% of alkali slag and 2-40wt% of fly ash;

[0009] The lead-zinc tailings slag is activated after high-temperature calcination, cooling to room temperature and ball milling to a particle size of less than 20μm; wherein the high-temperature calcination temperature is 500-1000℃, the high-temperature calcination time is 3-6h, the ball milling speed is 120-200r / min, and the alkali activator used for activation is alkali slag percolate. Preferably, the high-temperature calcination temperature is 800℃, and the time is 4h.

[0010] In some preferred embodiments, the operation of activation is: mixing the lead-zinc tailings slag and the alkali activator according to a mass ratio of 5:1, and then reacting at 24-34 DEG C for 1-5 hours, and then obtaining.

[0011] In some preferred embodiments, the mass ratio of seawater to solid waste main material is 2:5.

[0012] In some preferred embodiments, the particle size of the lead-zinc tailings slag is less than 20 microns, and the water content is less than 5 wt%.

[0013] In some preferred embodiments, the particle size of the alkali slag is less than 75 microns, and the calcium oxide content is higher than 80 wt%.

[0014] In some preferred embodiments, the pH value of the alkali slag leaching solution is 12-14.

[0015] In some preferred embodiments, the particle size of the fly ash is less than 75 microns, and the water content is less than 2 wt%.

[0016] A preparation method of a seawater-mixed high-pressure salt corrosion resistant full-solid waste anti-seepage grouting material, comprising the following steps:

[0017] (1) The lead-zinc tailings slag is sequentially subjected to high-temperature calcination, cooling to room temperature, and then ball milling to a particle size of less than 20 microns for standby; wherein the high-temperature calcination temperature is 800 DEG C, the high-temperature calcination time is 4 hours, and the ball milling speed is 120-200 r / min;

[0018] The alkali slag is dried and ground, and then sieved with a screen mesh having a pore size of 75 microns for standby;

[0019] The fly ash is dried and ground, and then sieved with a screen mesh having a pore size of 75 microns for standby;

[0020] (2) The lead-zinc tailings slag treated in step (1) is mixed with the alkali activator according to a mass ratio of 5:1, and then reacted at 30 DEG C for 1-5 hours to obtain activated lead-zinc tailings slag;

[0021] (3) The activated lead-zinc tailings slag, the alkali slag, and the fly ash are mixed according to a mass ratio of 30-50:30-48:2-40 to obtain a solid waste main material;

[0022] (4) The seawater and the solid waste main material are mixed to obtain a high-pressure salt corrosion resistant full-solid waste anti-seepage grouting material.

[0023] In some preferred embodiments, the mass ratio of seawater to solid waste main material is 2:5.

[0024] The present application has at least the following beneficial effects:

[0025] (1) The high-pressure salt corrosion resistant full solid waste anti-seepage grouting material prepared by the application has good anti-seepage performance and still has excellent performance under high-pressure salt corrosion environment.

[0026] (2) The raw materials used in the application are almost "zero cost": the solid raw materials are all taken from solid waste, realizing solid waste resource utilization; the strong alkaline leachate of an alkali residue field is used as an alkali activator to treat waste with waste; finally, seawater is used for mixing according to local conditions, which not only saves a large amount of fresh water resources, but also improves the anti-seepage performance.

[0027] (3) The preparation method used in the application is simple and convenient for large-scale production. DETAILED DESCRIPTION

[0028] The technical solutions of the application are further described and explained through specific embodiments.

[0029] In the following examples, if no special instructions are given, the water used can be one or more of distilled water, pure water, drinking water; the performance indicators of fly ash not specifically mentioned can refer to GB / T 1596-2017; the detection methods in the following examples are all conventional detection methods if no special instructions are given; the reagents in the following examples are all purchased from commercial channels if no special instructions are given.

[0030] I. Preparation of high-pressure salt corrosion resistant full solid waste anti-seepage grouting material

[0031] The preparation method comprises the following steps:

[0032] (1) The lead-zinc tailings are sequentially subjected to high-temperature calcination, cooling to room temperature and then ball milling to a particle size of less than 20 mu m for standby;

[0033] The temperature of high-temperature calcination is 800 DEG C, the time of high-temperature calcination is 4h, and the rotation speed of ball milling is 120-200r / min; the water content of the lead-zinc tailings after the above treatment is less than 5wt%.

[0034] (2) The alkali residue is dried and ground, and then sieved with a sieve with a pore size of 75 mu m for standby, wherein the calcium oxide content of the alkali residue is higher than 80wt%.

[0035] (3) The fly ash is dried to a water content of less than 2wt% and then ground, and finally sieved with a sieve with a pore size of 75 mu m for standby.

[0036] (4) The lead-zinc tailings after step (1) treatment and the alkali activator are mixed in a mass ratio of 5:1, and then reacted at 30 DEG C for a period of time (activation time) to obtain activated lead-zinc tailings.

[0037] (5) The activated lead-zinc tailings, alkali residue and fly ash are mixed with a J16 cement mixer for 300s to obtain a solid waste main material.

[0038] (6) The seawater and solid waste main material are mixed in a 80*100 mm cylindrical mold according to a mass ratio of 2:5, then demolded after curing for 24 h under room temperature conditions of 20 ± 2 ℃ and a relative humidity environment of ≥ 50%, and continue to cure for 7 d to obtain the test sample corresponding to each example.

[0039] The feeding ratio and excitation time of each example are shown in Table 1:

[0040] Table 1 Preparation parameters of examples 1-7

[0041]

[0042] II. Performance test

[0043] (1) Impermeability test under pressure-free conditions

[0044] According to the soil test procedure GB50123-2019, the results are shown in Table 2.

[0045] Table 2 Permeability coefficient of examples 1-7 under pressure-free conditions

[0046] Test sample Permeability coefficient m / s Example 1 2.37 x 10 -9 ]] Example 2 8.49 x 10 -10 ]] Example 3 6.24 x 10 -10 ]] Example 4 6.07 x 10 -10 ]] Example 5 4.47 x 10 -10 ]] Example 6 8.64 x 10 -10 ]] Example 7 7.82 x 10 -10 ]]

[0047] From examples 1-4, it can be seen that within a certain time range, the impermeability of the high-pressure salt corrosion resistant full solid waste impermeable grouting material is positively correlated with the excitation time of the lead-zinc tailings, and when the excitation time is 1 h, the permeability coefficient is 2.37×10 -9 m / s, and after 2 h of excitation, the permeability coefficient decreases by an order of magnitude to 8.49×10 -10 m / s; in comparison, after 3 h and 4 h of excitation, the permeability coefficient changes little, being 6.24×10 -10 m / s and 6.07×10 -10 m / s, respectively. Overall, the impermeability of the cured grout is excellent and improves with the increase of the excitation time of the tailings.

[0048] Comparing comparative example 3, example 5 and example 6, it can be seen that the higher the lead-zinc tailings content, the larger the permeability coefficient, and when the tailings content is between 30-50%, the permeability coefficient is stable within the order of 4-9×10 -10 m / s, showing excellent impermeability. Comparing comparative example 3 and example 7, it can be seen that the lower the alkali slag content, the larger the permeability coefficient, and the alkali slag content between 30-48% can achieve good impermeability.

[0049] (2) Impermeability test of traditional cement grout and high-pressure salt corrosion resistant full solid waste impermeable grouting material under high pressure-salt corrosion

[0050] Test instrument: The test was conducted by using high water pressure plate and rigid wall permeameter, and the high water pressure plate was GEOTACM10000 standard water pressure plate.

[0051] Test environment: According to the required ion solution in the simulation seawater in the standard ASTM D1148-98, the concentrations of chloride ion (19.4 mg / L), sulfate ion (2.77 mg / L) and magnesium ion (1.31 mg / L) were calculated, and the corrosion conditions of complex ions in the actual environment were simulated.

[0052] Test sample: The preparation methods of examples 3 and 5-7 were as shown above, and the ordinary portland cement was P.O.42.5R cement. The specific test conditions and test results are shown in table 3.

[0053] Table 3 Test conditions and test results of permeability coefficient under high pressure-salt corrosion conditions

[0054] Test sample Water pressure Dissolution environment Permeability coefficient m / s Example 3 0 Water 6.24 x 10 -10 ]]> Example 3 0.25 MPa Water 6.37 x 10 -10 ]]> Example 3 0.50 MPa Water 6.94 x 10 -10 ]] Example 3 0.75 MPa Water 7.23 x 10 -10 ]] Example 3 0.75 MPa Chloride 7.62 x 10 -10 ]] Example 5 0.75 MPa Chloride 6.88 x 10 -10 ]] Example 6 0.75 MPa Chloride 8.04 x 10 -10 ]] Example 7 0.75 MPa Chloride 7.85 x 10 -10 ]]> Example 3 0.75 MPa Sulfate 7.29 x 10 -10 ]] Example 5 0.75 MPa Sulfate 6.74 x 10 -10 ]] Example 6 0.75 MPa Sulfate 7.83 x 10 -10 ]] Example 7 0.75 MPa Sulfate 7.41 x 10 -10 ]]> Example 3 0.75 MPa Magnesium 8.46 x 10 -10 ]]> Example 5 0.75 MPa Magnesium 8.04 x 10 -10 ]] Example 6 0.75 MPa Magnesium 9.23 x 10 -10 ]]> Example 7 0.75 MPa Magnesium 8.64 x 10 -10 ]]> Ordinary Portland cement 0.75 MPa Water 9.22 x 10 -10 ]]> Ordinary Portland cement 0.75 MPa Chloride 2.18 x 10 -9 ]]> Ordinary Portland cement 0.75 MPa Sulfate 4.43 x 10 -9 ]] Ordinary Portland cement 0.75 MPa Magnesium 9.46 x 10 -9 ]]>

[0055] According to the above table, the permeability coefficient of the high-pressure salt corrosion resistant full solid waste anti-permeation grouting material in water under the pressure of 0-0.75 MPa is 6.24-7.23×10 -10 m / s, which indicates that the material has excellent anti-permeation effect under high pressure in water, and the permeability coefficient (7.23×10 -10 m / s) thereof in water under the same pressure is lower than the permeability coefficient (9.22×10 -10 m / s) of the ordinary portland cement.

[0056] Under the condition of high pressure (0.75 MPa water pressure) coupled with chloride ion, the permeability coefficient of the high-pressure salt corrosion resistant full solid waste anti-permeation grouting material is relatively low, and fluctuates in the range of 6.88-8.04×10 -10 m / s, which is much lower than the permeability coefficient (2.18×10 -9 m / s) of the ordinary portland cement under the same chloride ion corrosion concentration.

[0057] Under the condition of high pressure (0.75 MPa water pressure) coupled with sulfate ion, the permeability coefficient of the high-pressure salt corrosion resistant full solid waste anti-permeation grouting material is relatively low, and fluctuates in the range of 6.74-7.83×10 -10 m / s, which is much lower than the permeability coefficient (4.43×10 -9 m / s) of the ordinary portland cement under the same sulfate ion corrosion concentration.

[0058] Under the condition of high pressure (0.75 MPa water pressure) coupled with magnesium ion, although the permeability coefficient of the high-pressure salt corrosion resistant full solid waste anti-permeation grouting material is slightly increased, and fluctuates in the range of 8.04-9.23×10-10 m / s, but still much lower than the permeability coefficient (9.46*10 -9 m / s) of ordinary Portland cement under the same magnesium ion corrosion concentration.

[0059] The above experiment shows that the high-pressure salt-resistant full-solid waste anti-seepage grouting material has a low permeability coefficient under high-pressure salt corrosion conditions, and the anti-seepage performance is better than that of traditional ordinary Portland cement.

[0060] The above description is only a preferred embodiment of the present application, and therefore cannot limit the scope of the present application. Any equivalent changes and modifications made in accordance with the scope of the present application and the content of the specification should still be within the scope of the present application.

Claims

1. A high-pressure salt corrosion resistant solid waste seepage prevention grouting material mixed with seawater, characterized in that, It is obtained by mixing solid waste with seawater; The solid waste main material consists of 30-50 wt% activated lead-zinc tailings slag, 30-48 wt% alkaline slag and 2-40 wt% fly ash; The lead-zinc tailings slag is calcined at high temperature, cooled to room temperature, ball-milled to a particle size of less than 20 μm, and then activated to obtain the activated lead-zinc tailings slag; wherein, the high-temperature calcination temperature is 500~1000℃, the high-temperature calcination time is 3~6h, the ball milling speed is 120~200r / min, and the alkaline activator used for activation is alkaline slag leachate.

2. The high-pressure salt corrosion resistant solid waste seepage-proof grouting material as described in claim 1, characterized in that, The activation process is as follows: the lead-zinc tailings slag and the alkaline activator are mixed at a mass ratio of 5:1 and reacted at 24~34℃ for 1~5 hours.

3. The high-pressure salt corrosion resistant solid waste seepage prevention grouting material as described in claim 1, characterized in that, The mass ratio of seawater to the main solid waste material is 2:

5.

4. The high-pressure salt corrosion resistant solid waste seepage prevention grouting material as described in claim 1, characterized in that, The lead-zinc tailings slag has a particle size of less than 20 μm and a moisture content of less than 5 wt%.

5. The high-pressure salt corrosion resistant solid waste seepage prevention grouting material as described in claim 1, characterized in that, The alkaline residue has a particle size of less than 75 μm and a calcium oxide content of more than 80 wt%.

6. The high-pressure salt corrosion resistant solid waste seepage-proof grouting material as described in claim 1, characterized in that, The pH value of the alkaline residue leachate is 12-14.

7. The high-pressure salt corrosion resistant solid waste seepage prevention grouting material as described in claim 1, characterized in that, The fly ash has a particle size of less than 75 μm and a moisture content of less than 2 wt%.

8. A method for preparing a high-pressure salt corrosion resistant solid waste seepage-proof grouting material mixed with seawater, characterized in that, Includes the following steps: (1) Lead-zinc tailings slag is successively calcined at high temperature, cooled to room temperature and then ball-milled to a particle size of less than 20 μm for later use; wherein, the high temperature calcination temperature is 800℃, the high temperature calcination time is 4h, and the ball milling speed is 120~200r / min; The alkali residue was dried and ground, and then sieved through a 75μm sieve for later use. The fly ash is dried and ground, then sieved through a 75μm sieve for later use. (2) The lead-zinc tailings slag treated in step (1) is mixed with the alkaline activator at a mass ratio of 5:1 and reacted at 30°C for 1 to 5 hours to obtain the activated lead-zinc tailings slag. (3) The activated lead-zinc tailings slag, the alkaline slag and the fly ash are mixed in a mass ratio of 30~50:30~48:2~40 to obtain the main solid waste material; (4) When using, seawater and the solid waste main material are mixed to obtain the high pressure salt corrosion resistant solid waste anti-seepage grouting material.

9. The preparation method according to claim 8, characterized in that, The mass ratio of seawater to the main solid waste material is 2:5.

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