Oily sludge-based foam light soil and preparation method thereof

Abstract

The invention discloses oily sludge-based foam light soil and a preparation method thereof, and belongs to the technical field of building materials, the oily sludge-based foam light soil comprises, by mass, 60%-80% of oily sludge pyrolysis powder, 5%-15% of cement, 10%-20% of water and 5%-10% of foam; in the preparation process, firstly, the oily sludge is subjected to pyrolysis treatment to prepare oily sludge pyrolysis powder with the oil content smaller than or equal to 2%, then the oily sludge pyrolysis powder is mixed with cement and water to form light soil slurry, the light soil slurry and foam liquid are mixed to prepare a light soil mixture, the flow value of the light soil mixture is measured, and then pouring, curing and curing are conducted to form the foam light soil. The preparation method of the oily sludge-based foam light soil is simple, the oily sludge-based foam light soil as a roadbed material meets the requirements of highway roadbed design specifications, the use amount of cement, fly ash and other raw materials in common foam light soil is reduced, pollution and harm of oily sludge pyrolysis powder to the environment can be solved, and the oily sludge-based foam light soil has good market prospects and application value.

Description

Technical Field

[0001] The invention relates to the technical field of building materials, in particular to an oil sludge-based foamed lightweight soil and a preparation method thereof. Background Art

[0002] In recent years, with the development of economy and the exploitation of oil in desert, the petrochemical industry has produced an average of 1 million tons of new oil sludge every year, and this amount is still on the rise. Foamed lightweight soil is a new type of lightweight geotechnical construction filler. It is a lightweight mixed material formed by mechanically stirring cementitious materials, aggregates, admixtures and water, and mixing them with foam made by a foaming device. The technical indicators such as density and strength can be adjusted by adjusting the mix ratio. It can be used in engineering projects such as roadbed filling, foundation pit backfilling and filling underground pipelines. It has many advantages such as light weight, adjustable strength, good fluidity, strong uprightness after curing, and excellent thermal insulation performance.

[0003] The cement-based foamed lightweight soil roadbed filling currently used belongs to large-volume lightweight soil pouring, which has high heat generation and poor crack resistance. Most foamed lightweight soils still use cement as the main cementing material, with high construction and production costs and serious resource and environmental problems in the process of cement production. Oil sludge comes from the process of oil extraction, refining, processing, transportation and production, and is a kind of oil solid waste that can be recycled. Oil sludge is used instead of cement to improve the performance of foamed lightweight soil, thereby further optimizing the use of foamed lightweight soil and making it widely used. At present, there has been research in China on the improvement of oil sludge for highway roadbed filling. Using oil sludge as a road construction material can greatly reduce the cost of road construction.

[0004] In the existing method of making roadbed filler from oil sludge, the oil sludge residue after chemical conditioning, centrifugation and pyrolysis process is used for roadbed filling, which affects its surrounding environment. The residue is mainly used for roadbed filling around oil wells or for roadbed filling of third- and fourth-level highways. The actual application scope of the project is relatively narrow and cannot meet the actual requirements of a wide range of projects. Summary of the invention

[0005] In view of the problems existing in the prior art, the present invention provides an oil sludge-based foamed lightweight soil and a preparation method thereof, so as to realize the recycling of oil sludge resources, and the performance of the prepared oil sludge-based foamed lightweight soil can meet the performance of engineering materials.

[0006] The present invention is achieved through the following technical solutions: In a first aspect, the present application provides an oil sludge-based foamed lightweight soil, which comprises, by mass percentage, 60%-80% of oil sludge pyrolysis powder, 5%-15% of cement, 10%-20% of water and 5%-10% of foam; The oil sludge pyrolysis powder is powder obtained by pyrolysis of oil sludge.

[0007] Preferably, the density of the oil sludge pyrolysis powder is in the range of 1.25 g / cm 3 -1.45g / cm 3 The particle size distribution is 0.075mm-0.600mm, which belongs to fine sand. The average organic matter content is 2.4%, the oil content is ≤2%, and the bulk density is >1500kg / cm 3 .

[0008] Preferably, the foam is a foam liquid formed by a foaming agent, and the foaming agent is a rosin acid soap foaming agent, a metal aluminum powder foaming agent, or a plant protein foaming agent.

[0009] Preferably, the dilution ratio of the foaming agent is 1:(35-50), and the foaming ratio is 600-800 times.

[0010] Preferably, the cement is P·042.5 ordinary Portland cement, with a final setting time of <240 min and a 28-day compressive strength of >42.5 MPa.

[0011] Preferably, the bulk density of the oil sludge-based foamed lightweight soil is 8 kN / m 3 -14kN / m 3 , the unconfined compressive strength is 0.68MPa~1.74MPa.

[0012] In a second aspect, the present application provides a method for preparing oil sludge-based foamed lightweight soil, comprising: 60%-80% of oil sludge pyrolysis powder, 5%-15% of cement and 10%-20% of water are mixed evenly to obtain a light soil slurry; Dilute 5%-10% of the foaming agent and foam to obtain a foam liquid; The lightweight soil slurry and the foam liquid are mixed and stirred evenly to obtain a lightweight soil mixture, and the lightweight soil mixture is solidified to obtain oil sludge-based foamed lightweight soil.

[0013] Preferably, the preparation method of the lightweight soil slurry is as follows: The oil sludge pyrolysis powder and cement are mixed evenly to obtain a mixed dry material, and water is added to the mixed dry material in batches and stirred evenly to obtain a light soil slurry.

[0014] Preferably, the oil sludge pyrolysis powder and cement are mixed in batches to obtain a mixed dry material.

[0015] In a third aspect, the present application provides an embankment, comprising the oil sludge-based foamed lightweight soil.

[0016] In a fourth aspect, the present application provides a highway comprising the oil sludge-based foamed lightweight soil.

[0017] Compared with the prior art, the present invention has the following beneficial technical effects: The oil sludge-based foamed lightweight soil provided in the present application uses 60-80% of oil sludge pyrolysis powder as the main raw material, providing an alternative and advantageous method for the treatment of oil sludge. The foamed lightweight soil made according to the "Highway Subgrade Design Specification" (JTGD30-2015) can meet the filler strength requirements of the roadbed, embankment or foundation of expressways, first-class highways, second-class and lower-class highways. It can not only consume a large amount of oil sludge, greatly reduce the use of cement, etc., save natural resources, realize the waste utilization of solid waste materials, but also reduce the harm of oil sludge to the environment, achieve the purpose of turning waste into treasure and protecting the environment, and at the same time produce certain economic benefits.

[0018] The preparation method of the oil sludge-based foamed lightweight soil is simple. As a roadbed material, it meets the requirements of highway roadbed design specifications, reduces the amount of raw materials such as cement and fly ash in ordinary foamed lightweight soil, can solve the pollution and harm to the environment caused by the pyrolysis powder of oil sludge, achieves comprehensive utilization of resources, protects the environment, and has good market prospects and application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0020] Figure 1 The present invention is a flow chart of the method for preparing the oil sludge-based foamed lightweight soil. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations.

[0022] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for which protection is sought, but merely represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0023] An oil sludge-based foamed lightweight soil comprises, by mass percentage, 60%-80% of oil sludge pyrolysis powder, 5%-15% of cement, 10%-20% of water and 5%-10% of foam.

[0024] The cement is P·042.5 ordinary Portland cement, with a final setting time of <240min and a 28-day compressive strength of >42.5MPa.

[0025] The oil sludge pyrolysis powder is obtained by pyrolysis of oil sludge, and the density of the oil sludge pyrolysis powder is in the range of 1.25 g / cm 3 -1.45g / cm 3 The particle size distribution is 0.075mm-0.600mm, which belongs to fine sand. The average organic matter content is 2.4%, the oil content is ≤2%, and the bulk density is >1500kg / cm 3 . The foam is a dilution of rosin acid soap foaming agent, metal aluminum powder foaming agent and plant protein foaming agent, the dilution ratio is 1: (35-50), and the foaming ratio is 600-800 times.

[0026] The preparation process of the foam is as follows: according to the mass dosage, 0.2-0.6 parts of foaming agent are added to 10-60 parts of water to dilute to form a foam liquid, and then an air compressor is used to generate the foam liquid, and the apparent density is 50kg / m 3 -60kg / m 3 .

[0027] The bulk density of the oil sludge-based foamed lightweight soil is 8kN / m 3 -14kN / m 3 The 28-day unconfined compressive strength of foam lightweight soil is 0.68MPa~1.74MPa.

[0028] Correspondingly, the present application also provides a method for preparing oil sludge-based foamed lightweight soil, comprising the following steps: Step 1, 60%-80% of oil sludge pyrolysis powder, 5%-15% of cement and 10%-20% of water are mixed uniformly to obtain a light soil slurry; During the preparation of the lightweight soil slurry, the oil sludge pyrolysis powder and cement are first mixed and stirred evenly to obtain a mixture, and then 2 / 3 of the total water is added to the mixture and stirred evenly, and then the remaining 1 / 3 of the water is added and stirred sufficiently to obtain a lightweight soil slurry. There should be no lumps of powder in the lightweight soil slurry.

[0029] The preparation method of the oil sludge pyrolysis powder is as follows: After the oil sludge is heated at a high temperature of 550-600°C for 4-5 hours, the light components in the petroleum are volatilized, and the remaining heavy components (mainly asphaltene) adhere to the solid residue, which is cooled for 6-7 hours to obtain the oil sludge pyrolysis powder; the oil content is ≤2%. The average density of the oil sludge pyrolysis powder is 1.44g / cm 3 The particle size distribution is 0.075mm-0.600mm, which belongs to fine sand. The average organic matter content is 2.4%, the oil content is ≤2%, and the bulk density is >1500kg / cm 3 .

[0030] Step 2: dilute 5%-10% of the foaming agent and foam to obtain a foam liquid, the dilution multiple being 40-50 times.

[0031] Step 3, mixing the light soil slurry of step 1 with the foam liquid of step 2, and stirring evenly to obtain a light soil mixture; Step 4: solidifying the lightweight soil mixture to obtain oil sludge-based foamed lightweight soil.

[0032] Example 1 An oil sludge-based foamed lightweight soil comprises, by mass percentage, 65% of oil sludge pyrolysis powder, 20% of cement, 10% of water and 5% of foam.

[0033] The preparation method of the oil sludge-based foamed lightweight soil is as follows: Step 1: 65% of the pyrolysis powder of the oil sludge and 20% of the cement are dry mixed in 4 batches in a forced single-horizontal shaft mixer at a speed of 40±5r / min for 5 minutes to uniformly mix the pyrolysis powder of the oil sludge and the cement to obtain a mixed dry material.

[0034] Step 2: Add 10% water twice into the mixer containing the mixed dry materials and stir for 5 minutes to obtain a uniform lightweight soil slurry; add 2 / 3 of the water for the first time and the remaining water for the second time. After stirring, there should be no lumps of powder in the lightweight soil slurry.

[0035] Step 3: dilute 5% of the foaming agent and water in a ratio of 1:35, and then pass the foaming agent through an air compressor to make an apparent density of 60kg / m 3 Foaming liquid.

[0036] Step 4: Mix the lightweight soil slurry obtained in step 2 and the foam obtained in step 3 for 3 minutes to obtain a lightweight soil mixture. The wet density of the lightweight soil mixture is 1200 kg / m 3 -1400kg / m 3 .

[0037] Step 5: pour the lightweight soil mixture into a mold, and obtain the oil sludge-based foamed lightweight soil after solidification.

[0038] Example 2 An oil sludge-based foamed lightweight soil comprises, by mass percentage, 70% of oil sludge pyrolysis powder, 15% of cement, 8% of water and 7% of foam.

[0039] The preparation method of the oil sludge-based foamed lightweight soil is as follows: Step 1: Dry mix 70% of the oil sludge pyrolysis powder and 15% of the cement in 5 batches in a forced single-horizontal shaft mixer at a speed of 40±5r / min for 5 minutes to evenly mix the oil sludge pyrolysis powder and cement to obtain a mixed dry material.

[0040] Step 2: Add 8% water twice into the mixer containing the mixed dry materials and stir for 5 minutes to obtain a uniform lightweight soil slurry; add 1 / 2 of the water for the first time and the remaining water for the second time. After stirring, there should be no lumps of powder in the lightweight soil slurry.

[0041] Step 3: Dilute 7% vegetable protein foaming agent and water at a ratio of 1:35, and then pass the foaming agent through an air compressor with the working pressure of the air compressor set to 0.7MPa-0.9MPa. The apparent density is 60kg / m 3 Foaming liquid.

[0042] Step 4: Mix the lightweight soil slurry obtained in step 2 and the foam obtained in step 3 and stir for 3 minutes to obtain a lightweight soil mixture.

[0043] Step 5: pour the lightweight soil mixture into a mold, and obtain the oil sludge-based foamed lightweight soil after solidification.

[0044] Example 3 An oil sludge-based foamed lightweight soil comprises, by mass percentage, 71% of oil sludge pyrolysis powder, 14% of cement, 5% of water and 10% of foam.

[0045] The preparation method of the oil sludge-based foamed lightweight soil is as follows: Step 1: Dry mix 71% of the oil sludge pyrolysis powder and 14% of the cement in 4 batches in a forced single-horizontal shaft mixer at a speed of 40±5r / min for 5 minutes to evenly mix the oil sludge pyrolysis powder and cement to obtain a mixed dry material.

[0046] Step 2: Add 5% water twice into the mixer containing the mixed dry materials and stir for 3 minutes to obtain a uniform lightweight soil slurry; add 1 / 3 of the water for the first time and the remaining water for the second time. After stirring, there should be no lumps of powder in the lightweight soil slurry.

[0047] Step 3: dilute 10% of the aluminum powder foaming agent and water at a ratio of 1:40, and then pass the foaming agent through an air compressor to make an apparent density of 60kg / m 3 Foaming liquid.

[0048] Step 4: Mix the lightweight soil slurry obtained in step 2 and the foam obtained in step 3 and stir for 3 minutes to obtain a lightweight soil mixture.

[0049] Step 5: pour the lightweight soil mixture into a mold, and obtain the oil sludge-based foamed lightweight soil after solidification.

[0050] Example 4 An oil sludge-based foamed lightweight soil comprises, by mass percentage, 73% of oil sludge pyrolysis powder, 11% of cement, 6% of water and 5% of foam.

[0051] The preparation method of the oil sludge-based foamed lightweight soil is as follows: Step 1: 73% of the pyrolysis powder of the oil sludge and 11% of the cement are dry mixed in three batches in a forced single-horizontal shaft mixer at a speed of 40±5 r / min for 5 minutes to uniformly mix the oil sludge powder and cement to obtain a mixed dry material.

[0052] Step 2: Add 6% water twice into the mixer containing the mixed dry materials and stir for 3 minutes to obtain a uniform lightweight soil slurry; add 1 / 3 of the water for the first time and the remaining water for the second time. After stirring, there should be no lumps of powder in the lightweight soil slurry.

[0053] Step 3: dilute 5% of rosin acid soap foaming agent and water at a ratio of 1:50, and then pass the foaming agent through an air compressor to make an apparent density of 60kg / m 3 Foaming liquid.

[0054] Step 4: Mix the lightweight soil slurry obtained in step 2 and the foam obtained in step 3 and stir for 3 minutes to obtain a lightweight soil mixture.

[0055] Step 5: pour the lightweight soil mixture into a mold, and obtain the oil sludge-based foamed lightweight soil after solidification.

[0056] Example 5 An oil sludge-based foamed lightweight soil comprises, by mass percentage, 60% of oil sludge pyrolysis powder, 15% of cement, 15% of water and 10% of foam.

[0057] The preparation method of the oil sludge-based foamed lightweight soil is the same as that in Example 1 and will not be repeated here.

[0058] Example 6 An oil sludge-based foamed lightweight soil comprises, by mass percentage, 80% of oil sludge pyrolysis powder, 5% of cement, 10% of water and 5% of foam.

[0059] The preparation method of the oil sludge-based foamed lightweight soil is the same as that in Example 1 and will not be repeated here.

[0060] Example 7 An oil sludge-based foamed lightweight soil comprises, by mass percentage, 65% of oil sludge pyrolysis powder, 5% of cement, 20% of water and 10% of foam.

[0061] Example 8 A road embankment comprises the oil sludge-based foamed lightweight soil.

[0062] Example 9 A highway comprising the embankment described in Example 8.

[0063] The preparation method of the oil sludge-based foamed lightweight soil is the same as that in Example 1 and will not be repeated here.

[0064] The oil sludge-based foamed lightweight soil of Examples 1-4 was subjected to compressive strength tests for 7 days, 14 days and 28 days, respectively. According to GB / Tl 7671-2021 "Test Method for Strength of Cement Mortar (ISO Method)", CJJ / T 177-2012 "Technical Specification for Filling Engineering of Bubble Mixed Lightweight Soil" and the test, the fluidity and strength of the oil sludge-based foamed lightweight soil were tested by a universal pressure testing machine, and the results are shown in Table 5.

[0065] Table 5

[0066] From the test results in Table 5, it can be seen that with the increase of the amount of oil sludge pyrolysis powder, the flow value of foamed lightweight soil is 150mm-170mm, which meets the national standard specifications for building materials. It also shows that oil sludge pyrolysis powder will increase the strength and crack resistance of foamed lightweight soil; the unconfined compressive strength of oil sludge-based foamed lightweight soil is 35%-45% higher than that of ordinary foamed lightweight soil. At the same time, its crack resistance, durability, and high hydration heat release have also been greatly improved. Due to the small amount of cement, the stability and controllability of the mix ratio are more guaranteed. The prepared foamed lightweight soil has a sufficiently high unconfined compressive strength and can meet the filling requirements of the roadbed, embankment or foundation of expressways, first-class highways, second-class and lower-class highways. It can not only consume a large amount of oil sludge pyrolysis powder, but also greatly reduce the use of cement and save production costs. By preparing oil sludge-based foamed lightweight soil, the rational use of oil sludge pyrolysis powder is realized, waste is turned into treasure, and the surrounding environment is greatly improved. At the same time, this preparation and production process is intuitive, the production efficiency is high, safe, and the production quality meets the construction requirements. It has a significant positive role and far-reaching effect on promoting the recycling of solid waste.

[0067] The above contents are only for explaining the technical idea of ​​the present invention and cannot be used to limit the protection scope of the present invention. Any changes made on the basis of the technical solution in accordance with the technical idea proposed by the present invention shall fall within the protection scope of the claims of the present invention.

Claims

1. An oil sludge-based foamed lightweight soil, characterized in that: By mass percentage, it includes 60%-80% of oil sludge pyrolysis powder, 5%-15% of cement, 10%-20% of water and 5%-10% of foam; The oil sludge pyrolysis powder is powder obtained by pyrolysis of oil sludge.

2. The oil sludge-based foamed lightweight soil according to claim 1, characterized in that: The density range of the oil sludge pyrolysis powder is 1.25 g / cm 3 -1.45g / cm 3 The particle size distribution is 0.075mm-0.600mm, which belongs to fine sand. The average organic matter content is 2.4%, the oil content is ≤2%, and the bulk density is >1500kg / cm 3 .

3. The oil sludge-based foamed lightweight soil according to claim 1, characterized in that: The foam is a foam liquid formed by a foaming agent, and the foaming agent is a rosin acid soap foaming agent, a metal aluminum powder foaming agent, or a plant protein foaming agent.

4. The oil sludge-based foamed lightweight soil according to claim 2, characterized in that: The dilution ratio of the foaming agent is 1:(35-50), and the foaming ratio is 600-800 times.

5. The oil sludge-based foamed lightweight soil according to claim 1, characterized in that: The bulk density of the oil sludge-based foamed lightweight soil is 8kN / m 3 -14kN / m 3 , the unconfined compressive strength is 0.68MPa~1.74MPa.

6. A method for preparing the oil sludge-based foamed lightweight soil according to any one of claims 1 to 5, characterized in that: include: 60%-80% of oil sludge pyrolysis powder, 5%-15% of cement and 10%-20% of water are mixed evenly to obtain a light soil slurry; Dilute 5%-10% of the foaming agent and foam to obtain a foam liquid; The lightweight soil slurry and the foam liquid are mixed and stirred evenly to obtain a lightweight soil mixture, and the lightweight soil mixture is solidified to obtain oil sludge-based foamed lightweight soil.

7. The method for preparing oil sludge-based foamed lightweight soil according to claim 6, characterized in that: The preparation method of the lightweight soil slurry is as follows: The oil sludge pyrolysis powder and cement are mixed evenly to obtain a mixed dry material, and water is added to the mixed dry material in batches and stirred evenly to obtain a light soil slurry.

8. The method for preparing oil sludge-based foamed lightweight soil according to claim 7, characterized in that: The oil sludge pyrolysis powder and cement are mixed in batches to obtain mixed dry materials.

9. A road embankment, characterized in that: It comprises the oil sludge-based foamed lightweight soil as described in any one of claims 1 to 5.

10. A highway, characterized in that: It comprises the oil sludge-based foamed lightweight soil as described in any one of claims 1 to 5.

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