Desert aeolian sand base material stabilized by salt lake brine and preparation method of desert aeolian sand base material

Abstract

The invention relates to the technical field of green building materials and road engineering, in particular to a desert aeolian sand base material stabilized by salt lake brine and a preparation method thereof.The desert aeolian sand base material is prepared from, by mass, 10.5-11.6 parts of salt lake brine, 4.2-5.7 parts of light calcined magnesia, 0.3-1.8 parts of II-grade fly ash, 95-100.0 parts of aeolian sand and 0.6-0.8 part of a composite water repellent agent. And the compressive strength is greater than or equal to 3.0 MPa and meets the requirements of highway base layers. The salt lake old brine and the aeolian sand are used as main raw materials, magnesium harm solid waste is digested, desert resources are utilized, the process is simple, early strength and energy saving are achieved, the cost is low, and the method is suitable for highway engineering in desert areas.

Description

Technical Field

[0001] This invention relates to the field of green building materials and road engineering technology, specifically to a method for stabilizing desert aeolian sand base material using salt lake brine and its preparation. Background Technology

[0002] Magnesium oxychloride cement (MOC) has advantages such as rapid hardening and early strength, wear resistance, and resistance to brine corrosion. However, traditional MOC mostly uses pure MgCl2 solution as a binder, which is costly and mainly used in non-load-bearing decorative products. Its application in road base courses is almost non-existent.

[0003] The salt lakes in southern Xinjiang produce large quantities of MgCl2-type brine as a byproduct, which causes magnesium damage due to a lack of utilization methods. Meanwhile, the Taklamakan Desert has vast reserves of aeolian sand, which are difficult to utilize as resources. Combining these two factors to prepare low-cost, early-strength road base materials could solve both resource and environmental problems at once. However, the aeolian sand particles are rounded and poorly graded, and the MOC system has insufficient water resistance, resulting in strength and durability that fail to meet engineering requirements. Summary of the Invention

[0004] To address the shortcomings of the existing technologies, the purpose of this invention is to provide a method for stabilizing desert aeolian sand base materials using salt lake brine and its preparation. The preparation method provided by this invention is simple, low-cost, and provides early strength and durability, achieving efficient utilization of old salt lake brine and aeolian sand, and meeting the technical requirements for highway base courses in desert areas.

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: A material for stabilizing desert aeolian sand base layer using salt lake brine is made from the following raw materials in parts by weight: 10.5-11.6 parts salt lake brine, 4.2-5.7 parts lightly calcined magnesium oxide, 0.3-1.8 parts Class II fly ash, 95-100.0 parts aeolian sand, and 0.6-0.8 parts composite water-resistant agent.

[0006] In a preferred embodiment of the present invention, the brine is a potassium extraction waste filtrate from a salt lake in southern Xinjiang, with a density of 1.331 g·cm³. -3 -1.336g·cm -3 Mg in salt lake brine 2+ The content is 96.0-107.4 g / L, Na + The content is 3.2g / L-3.6g / L, K + The content is 2.5g / L-2.9g / L, SO4 2- The content was 40.0 g / L-46.2 g / L, Cl - The content of [specific component] is 298.3g / L-298.0g / L, and the content of other components is 6.9g / L-7.3g / L.

[0007] In a preferred embodiment of the present invention, the preparation method of the desert aeolian sand base material stabilized by salt lake brine is as follows: lightly calcined magnesium oxide, Class II fly ash, aeolian sand, salt lake brine and composite water-resistant agent are mixed as raw materials and cured to obtain the desert aeolian sand base material stabilized by salt lake brine.

[0008] In a preferred embodiment of the present invention, the composite water-resistant agent consists of phosphate, sodium polyacrylate, and corn starch, with the mass ratio of phosphate, sodium polyacrylate, and corn starch being 1.0-1.5: 2.5-3.0: 0.5-1.0.

[0009] In a preferred embodiment of the present invention, the particle size of the aeolian sand is 0.15mm-4.75mm.

[0010] The preparation method of lightly calcined magnesium oxide includes the following steps: After sieving and dissolving the quicklime, a lime slurry is obtained.

[0011] Lime slurry is added to salt lake brine, allowed to stand, filtered, dried, and calcined to obtain lightly calcined magnesium oxide.

[0012] In a preferred embodiment of the present invention, the activity of the slaked lime is 75%, and the mass fraction of the slaked lime in the lime slurry is 40%.

[0013] In a preferred embodiment of the present invention, the standing time is 24 hours, the calcination temperature is 600°C, and the calcination time is 1 hour.

[0014] Another object of the present invention is to provide a desert aeolian sand base material prepared by any of the above-described preparation methods.

[0015] This invention utilizes salt lake brine to stabilize desert aeolian sand base materials for use in highway base engineering in desert areas.

[0016] Compared with the prior art, the beneficial effects of the present invention are: This invention relates to a method for preparing a base course material for aeolian sand in desert areas using salt lake brine. The base course material prepared by this invention features early setting and high strength, which can accelerate the construction progress of highway base courses. It also has high compressive strength (≥3.0 MPa), meeting the technical requirements for highway base courses in desert areas. The formula and preparation method of the base course material for aeolian sand in desert areas provided by this invention result in a product that is simple to operate, reduces the amount of silicate cement used, protects limited crushed stone resources, reduces energy consumption, solves the problem of magnesium stagnation in the local area, provides a new approach for the development and utilization of salt lake resources in southern Xinjiang, and promotes local economic development. Attached Figure Description

[0017] Figure 1 This is a flowchart illustrating the implementation process of the present invention. Detailed Implementation

[0018] The following detailed description, in conjunction with embodiments of the present invention and accompanying drawings, provides a clear and complete illustration of the technical solutions in these embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0019] It should be noted that all technical terms used in this invention are for the purpose of describing specific embodiments only and are not intended to limit the scope of protection of this invention. Unless otherwise specified, all raw materials, reagents, instruments and equipment used in the following embodiments of this invention can be purchased from the market or prepared by existing methods.

[0020] The Class II fly ash was produced by a building materials company in Xinjiang, and the salt lake brine was the filtrate from potassium extraction waste from a salt lake in southern Xinjiang.

[0021] Example 1 A method for preparing desert aeolian sand base material using salt lake brine includes the following steps: (8) Pass quicklime with an activity of 75% through a 0.075mm sieve, prepare a lime slurry with a solid content of 40%, add it to the brine of the salt lake, let it stand for 24 hours, filter, dry, and calcine at 600℃ for 1 hour to obtain light calcined magnesium oxide. The activity content of the light calcined magnesium oxide is determined to be 60.0%.

[0022] (9) Weigh 9.5g of lightly calcined magnesium oxide, then weigh 0.3g of grade II fly ash and 100.0g of aeolian sand, mix them with the lightly calcined magnesium oxide and stir evenly to obtain dry material.

[0023] (10) Then weigh 11.6g of salt lake brine and add 0.6g of composite water-resistant agent to obtain liquid material.

[0024] (11) Add the liquid material to the dry material and stir evenly. Pour into the mold, compact, and cure in a natural environment for 24 hours before demolding to obtain a desert aeolian sand base material stabilized by salt lake brine.

[0025] Example 2 A method for preparing desert aeolian sand base material using salt lake brine includes the following steps: (1) The slaked lime with an activity of 75% was passed through a 0.075 mm sieve, and a lime slurry with a solid content of 40% was prepared. The lime slurry was added to the brine of the salt lake and left to stand for 24 hours. After filtration, drying, and calcination at 600℃ for 1 hour, the light-burned magnesium oxide was obtained. The activity content of the light-burned magnesium oxide was determined to be 60.0%.

[0026] (2) Weigh 9.0g of lightly calcined magnesium oxide with an active content of 60.0%, weigh 0.6g of grade II fly ash and 100.0g of aeolian sand in sequence, mix them with the lightly calcined magnesium oxide and stir evenly to obtain dry material.

[0027] (3) Then weigh 11.6g of salt lake brine and add 0.6g of composite water-resistant agent to obtain liquid material. (4) Add the liquid material to the dry material and stir evenly, pour into the mold, compact, and cure in a natural environment for 24 hours before demolding to obtain a desert aeolian sand base material stabilized by salt lake brine.

[0028] Example 3 A method for preparing desert aeolian sand base material using salt lake brine includes the following steps: (1) The slaked lime with an activity of 75% was passed through a 0.075 mm sieve, and a lime slurry with a solid content of 40% was prepared. The lime slurry was added to the brine of the salt lake and left to stand for 24 hours. After filtration, drying, and calcination at 600℃ for 1 hour, the light-burned magnesium oxide was obtained. The activity content of the light-burned magnesium oxide was determined to be 60.0%.

[0029] (2) Weigh 8.5g of lightly calcined magnesium oxide with an active content of 60.0%, weigh 0.9g of grade II fly ash and 100.0g of aeolian sand in sequence, mix them with the lightly calcined magnesium oxide and stir evenly to obtain dry material.

[0030] (3) Then weigh 11.2g of salt lake brine and add 0.6g of composite water-resistant agent to obtain liquid material.

[0031] (4) Add the liquid material to the dry material and stir evenly. Pour into the mold, compact, and cure in a natural environment for 24 hours before demolding to obtain a desert aeolian sand base material stabilized by salt lake brine.

[0032] Example 4 A method for preparing desert aeolian sand base material using salt lake brine includes the following steps: (1) The slaked lime with an activity of 75% was passed through a 0.075 mm sieve, and a lime slurry with a solid content of 40% was prepared. The lime slurry was added to the brine of the salt lake and left to stand for 24 hours. After filtration, drying, and calcination at 600℃ for 1 hour, the light-burned magnesium oxide was obtained. The activity content of the light-burned magnesium oxide was determined to be 60.0%.

[0033] (2) Weigh 8g of lightly calcined magnesium oxide with an active content of 60.0%, weigh 0.6g of grade II fly ash and 100.0g of aeolian sand in sequence, mix them with the lightly calcined magnesium oxide and stir evenly to obtain dry material.

[0034] (3) Then weigh 10.9g of salt lake brine and add 0.6g of composite water-resistant agent to obtain liquid material.

[0035] (4) Add the liquid material to the dry material and stir evenly. Pour into the mold, compact, and cure in a natural environment for 24 hours before demolding to obtain a desert aeolian sand base material stabilized by salt lake brine.

[0036] Example 5 A method for preparing desert aeolian sand base material using salt lake brine includes the following steps: (1) The slaked lime with an activity of 75% was passed through a 0.075 mm sieve, and a lime slurry with a solid content of 40% was prepared. The lime slurry was added to the brine of the salt lake and left to stand for 24 hours. After filtration, drying, and calcination at 600℃ for 1 hour, the light-burned magnesium oxide was obtained. The activity content of the light-burned magnesium oxide was determined to be 60.0%.

[0037] (2) Weigh 7.5g of lightly calcined magnesium oxide with an active content of 60.0%, weigh 0.6g of grade II fly ash and 100.0g of aeolian sand in sequence, mix them with the lightly calcined magnesium oxide and stir evenly to obtain dry material.

[0038] (3) Then weigh 10.8g of salt lake brine and add 0.6g of composite water-resistant agent to obtain liquid material.

[0039] (4) Add the liquid material to the dry material and stir evenly. Pour into the mold, compact, and cure in a natural environment for 24 hours before demolding to obtain a desert aeolian sand base material stabilized by salt lake brine.

[0040] Results Analysis The component combinations of the salt lake brine stabilized desert aeolian sand base material prepared in Examples 1-5 are shown in Table 1. The 3-day compressive strength of the salt lake brine stabilized desert aeolian sand base material prepared in Example 1 is 4.2 MPa, while the requirement of 3.0 MPa for highway base courses is 3.0 MPa. Therefore, it can be used for road construction, as shown in Table 2.

[0041] The 3-day compressive strength of the salt lake brine-stabilized desert aeolian sand base material prepared in Example 2 is 4.7 MPa, which is 3.0 MPa as required for highway base courses, and it can be used for pavement construction, as shown in Table 2.

[0042] The 3-day compressive strength of the salt lake brine stabilized desert aeolian sand base material prepared in Example 3 is 6.5 MPa, while the highway base layer requires 3.0 MPa, so it can be used for pavement construction, as shown in Table 2.

[0043] The 3-day compressive strength of the salt lake brine stabilized desert aeolian sand base material prepared in Example 4 is 5.2 MPa, while the highway base layer requires 3.0 MPa, so it can be used for pavement construction, as shown in Table 2.

[0044] The 3-day compressive strength of the salt lake brine stabilized desert aeolian sand base material prepared in Example 5 is 4.7 MPa, which exceeds the 3.0 MPa requirement for highway base courses, and it can be used for pavement construction, as shown in Table 2.

[0045] Therefore, the salt lake brine-stabilized desert aeolian sand base material prepared by this invention can be used for road construction and meets the technical requirements of highway base courses in desert areas.

[0046] Table 1 shows the component proportions of the salt lake brine-stabilized desert aeolian sand base material prepared in Examples 1-5. Table 2 shows the maximum dry density and optimum moisture content compressive strength of MOCB (Medium Dry Fiber) base material for desert aeolian sand foundation prepared in Examples 1-5. It should be noted that when numerical ranges are involved in this invention, it should be understood that both endpoints of each numerical range and any value between the two endpoints can be selected. Since the steps and methods used are the same as in the embodiments, preferred embodiments are described here to avoid redundancy. Although preferred embodiments of the invention have been described, those skilled in the art, once they understand the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this invention.

[0047] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A material for stabilizing desert aeolian sand base layer using salt lake brine, characterized in that, It is made from the following raw materials in parts by weight: 10.5-11.6 parts of salt lake brine, 4.2-5.7 parts of lightly calcined magnesium oxide, 0.3-1.8 parts of Grade II fly ash, 95-100.0 parts of aeolian sand and 0.6-0.8 parts of composite water-resistant agent.

2. The desert aeolian sand base material stabilized by salt lake brine according to claim 1, characterized in that, Salt lake brine is the filtrate from potassium extraction waste, with a density of 1.331 g·cm³. -3 -1.336g·cm -3 Mg in salt lake brine 2+ The content is 96.0 g / L-107.4 g / L, Na + The content is 3.2g / L-3.6g / L, K + The content is 2.5g / L-2.9g / L, SO4 2- The content was 40.0 g / L-46.2 g / L, Cl - The content of [specific component] is 298.3g / L-298.0g / L, and the content of other components is 6.9g / L-7.3g / L.

3. The desert aeolian sand base material stabilized by salt lake brine according to claim 1, characterized in that, The preparation method of desert aeolian sand base material stabilized by salt lake brine is as follows: lightly calcined magnesium oxide, grade II fly ash, aeolian sand, salt lake brine and composite water-resistant agent are mixed as raw materials to obtain desert aeolian sand base material stabilized by salt lake brine.

4. The method for preparing desert aeolian sand base material using salt lake brine according to claim 3, characterized in that, The composite water-resistant agent consists of phosphate, sodium polyacrylate, and corn starch, with a mass ratio of phosphate, sodium polyacrylate, and corn starch of 1.0-1.5:2.5-3.0:0.5-1.

0.

5. The method for preparing desert aeolian sand base material using salt lake brine according to claim 3, characterized in that, The particle size of aeolian sand ranges from 0.15 mm to 4.75 mm.

6. A desert aeolian sand base material stabilized by salt lake brine, prepared by any one of claims 1-5.

7. The desert aeolian sand base material stabilized by salt lake brine according to claim 6, characterized in that, Compressive strength ≥ 3.0 MPa.

8. The application of the desert aeolian sand base material stabilized by salt lake brine as described in claim 7 in highway base engineering in desert areas.

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