Preparation method of oily sludge-based inorganic ecostone

Abstract

The preparation method of the oily sludge-based inorganic ecostone comprises the following steps: S1, uniformly mixing and stirring oily sludge and water, naturally precipitating, separating an oil phase from a liquid phase and a solid phase, and collecting to obtain liquid-phase and solid-phase oily sludge mixed slurry; s2, adding a demulsifier into the mixed slurry of the liquid-phase oily sludge and the solid-phase oily sludge, mixing and stirring, naturally precipitating, and collecting to obtain solid-phase slurry; s3, uniformly mixing and stirring the solid-phase slurry, Portland cement, a curing compound agent and aggregate to obtain oil-containing sludge-based inorganic ecological stone raw material slurry; and S4, carrying out compression molding on the oily sludge-based inorganic ecological stone raw material slurry, and curing to prepare the oily sludge-based inorganic ecological stone. The oily sludge inorganic ecostone has the advantages of excellent mechanical properties and low water absorption, can be applied to road construction, greening engineering and outdoor landscape design, and has wide application scenarios.

Description

Technical Field

[0001] The patent of this invention relates to the field of separation and utilization technology, and specifically to a method for preparing oily sludge-based inorganic eco-stone. Background Art

[0002] Oily sludge is mainly oily solid waste generated during the process of oil extraction, transportation, storage and refining. It has a complex composition and contains multiple oil substances, suspended solids and a large amount of toxic substances such as benzene and phenol. It can cause harm to the human body, ecology and environment, and has therefore been included in the "National List of Hazardous Wastes".

[0003] The treatment and disposal of oily sludge must not only meet the development requirements of sustainable resource utilization, but also take into account the dual goals of harmless disposal and resource utilization. In the application of oily sludge treatment technology, on the one hand, the water, oil and solid particles in the oily sludge form stable oil-in-water (W / O) emulsions, water-in-oil (O / W) emulsions or complex multiple emulsion structures, which greatly increases the difficulty of oil-water-solid three-phase separation. On the other hand, due to the high proportion of petroleum hydrocarbons in oily sludge and their significant environmental hazards, the treatment technology of oily sludge mainly focuses on the recovery of petroleum hydrocarbons in the oil phase, while the disposal of the solid phase mostly adopts landfill or biological treatment, and the technology for its resource utilization is still relatively rare.

[0004] In the prior art, Chinese invention patent CN 116924648A discloses a method for treating oily sludge, in which oily sludge, a demulsifier, and a flocculant are mixed to achieve three-phase separation to obtain water, oil, and solidified oily sludge. The solidified oily sludge is mixed with a coal-water slurry and allowed to settle, and the resulting oily sludge-water slurry and the remaining oily sludge are incinerated to convert the oily sludge into products such as gas and ash.

[0005] Chinese invention patent CN 118388179A discloses a method for preparing road base concrete based on oily sludge. The method involves drying the oily sludge, then pyrolyzing it with modified diatomaceous earth as a catalyst to produce a pyrolysis residue. The residue is then mixed with fly ash, silica fume, and cement to create the road base concrete. Testing revealed that the maximum 28-day strength of a standard concrete test block was 44 MPa.

[0006] Existing technologies for the comprehensive resource utilization of oily sludge, as shown in the aforementioned patents, primarily focus on the recovery and utilization of crude oil resources in the oily sludge. The remaining solid phase is typically incinerated or landfilled, lacking resource utilization of the solid phase in the oily sludge. Furthermore, the utilization of the remaining solid phase after oily sludge treatment requires further high-temperature pyrolysis or incineration to obtain residue or ash. However, high-temperature pyrolysis or incineration processes are complex, energy-intensive, require high-quality equipment, and pose the risk of secondary pollution. Summary of the Invention

[0007] The purpose of the present invention is to solve the existing technical problems and to propose a method for preparing oily sludge-based inorganic eco-stone.

[0008] In order to achieve the above object, the present invention adopts the following technical solution: a method for preparing oily sludge-based inorganic eco-stone, comprising the following steps: S1: Mix the oily sludge and water and stir them evenly. After natural sedimentation, separate the oil phase from the liquid phase and the solid phase, and collect the liquid phase and solid phase oily sludge mixed slurry; S2: adding a demulsifier to the mixture of the liquid phase and the solid phase oily sludge, mixing and stirring, collecting the solid phase sludge after natural sedimentation; S3: mixing and stirring the solid phase slurry, silicate cement, curing compound and aggregate to obtain oily sludge-based inorganic eco-stone raw material slurry; S4: Pressing the oil-containing sludge-based inorganic eco-stone raw material slurry into shape, and curing it to prepare the oil-containing sludge-based inorganic eco-stone.

[0009] Furthermore, in S1, the amount of water added is 1 to 3 times the mass of the oily sludge, and the natural sedimentation time is 2 to 4 hours.

[0010] Furthermore, in S2, the demulsifier is a polyether demulsifier, and the amount of the demulsifier added is 0.1 to 3% of the mass of the oily sludge.

[0011] Furthermore, in S2, the stirring speed is 60 to 200 r / min, the stirring time is 5 to 15 min, and the natural sedimentation time is 2 to 4 h.

[0012] Furthermore, in S3, the mass ratio of the solid phase slurry, silicate cement, curing compound and aggregate is 30-60:15-30:4-15:15-30.

[0013] Furthermore, in S3, the curing compound is a mixture of calcium oxide, magnesium oxide, calcium carbonate, silica fume and steel slag powder in a mass ratio of 5-10:5-10:15-25:5-10:45-60, and the aggregate is medium-coarse sand.

[0014] Furthermore, in S4, the pressing pressure is 15 to 50 MPa, and the pressing time is 70 to 150 s.

[0015] Furthermore, in S4, the curing is natural curing, and the time is 14 to 28 days.

[0016] Furthermore, in S4, the curing is standard curing, with a temperature of 18 to 22° C., a standard curing humidity of 95 to 100%, and a standard curing time of 14 to 28 days.

[0017] The beneficial effects of the present invention are: (1) The present invention utilizes a demulsifier to destroy the stable emulsified system of oily sludge, thereby realizing the oil-water-solid three-phase separation of oily sludge. Not only can the oil phase component of the oily sludge be recovered, but the oil content in the collected solid phase is low, which meets the standard of SY / T 7301-2016 and can be used as a raw material for inorganic eco-stone, thereby realizing the comprehensive resource utilization of oily sludge to the greatest extent.

[0018] (2) The preparation method provided by the present invention does not require high-temperature treatment of oily sludge, does not produce dioxins and other harmful substances, reduces treatment costs and environmental risks, has a high utilization rate of oily sludge, and has low process construction investment and energy consumption.

[0019] (3) The oily sludge inorganic eco-stone prepared by the present invention has a 28-day compressive strength of 50-60 MPa, a flexural strength of 7-12 MPa, and a water absorption rate of 4-6%. It has excellent mechanical properties and low water absorption rate. It can be used in road construction, greening projects, and outdoor landscape design, with a wide range of application scenarios. The preparation method provided by the present invention has positive guiding significance for the comprehensive resource utilization of oily sludge, is more in line with environmental protection requirements, and is in line with the concepts of sustainable development and green development. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 Graph showing the oil content of the solid phase mud according to various embodiments of the present invention.

[0021] Figure 2 This is a physical picture obtained in Example 1. DETAILED DESCRIPTION

[0022] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0023] Example 1 Combined with the attached Figure 1-2 This embodiment provides a method for preparing oily sludge-based inorganic eco-stone, comprising the following steps: S1: The oily sludge obtained from the oil field after dehydration and drying treatment, with an oil content of 8%, is mixed with water. The amount of water added is twice the mass of the oily sludge. The mixture is stirred evenly and allowed to stand for natural sedimentation at room temperature for 3 hours. The oil phase is separated from the liquid phase and the solid phase, and the liquid phase and solid phase oily sludge mixture slurry is collected.

[0024] S2: A demulsifier was added to the mixture of liquid and solid oily sludge. The demulsifier was a polyether demulsifier, and the amount of demulsifier added was 0.5% of the mass of the oily sludge. The mixture was mixed and stirred evenly in a concrete mixer at a stirring speed of 150 r / min. After stirring for 5 minutes, the mixture was allowed to stand and naturally settle at room temperature for 3 hours. The solid phase mud was collected, and the oil content of the solid phase mud was 1.24%.

[0025] S3: According to the mass percentage, 60 wt% of solid phase mud, 15 wt% of silicate cement, 5 wt% of curing compound and 20 wt% of aggregate are mixed and stirred evenly to obtain oily sludge-based inorganic eco-stone raw material slurry, wherein the curing compound is a mixture of calcium oxide, magnesium oxide, calcium carbonate, silica fume and steel slag powder in a mass ratio of 7:8:20:10:55, and the aggregate is medium-coarse sand.

[0026] S4: The oily sludge-based inorganic eco-stone raw material slurry is pressed into shape at a pressing pressure of 30 MPa and a pressing time of 100 s. After pressing and molding, it is placed under standard curing conditions of 20°C and 100% humidity for 28 days to prepare the oily sludge-based inorganic eco-stone.

[0027] Example 2 This embodiment provides a method for preparing oily sludge-based inorganic eco-stone, comprising the following steps: S1: The oily sludge obtained from the oil field and dehydrated and dried is mixed with water. The oil content of the oily sludge is 8%, and the amount of water added is 3 times the mass of the oily sludge. The mixture is stirred evenly and allowed to stand for natural sedimentation at room temperature for 2 hours. The oil phase is separated from the liquid phase and the solid phase, and the liquid phase and solid phase oily sludge mixed slurry is collected.

[0028] S2: A demulsifier was added to the mixture of liquid and solid oily sludge. The demulsifier was a polyether demulsifier and the amount of demulsifier added was 1% of the mass of the oily sludge. The mixture was mixed and stirred evenly in a concrete mixer at a stirring speed of 120 r / min. After stirring for 10 minutes, the mixture was allowed to stand and naturally settle at room temperature for 2 hours. The solid phase sludge was collected and the oil content of the solid phase sludge was 0.98%.

[0029] S3: According to mass percentage, 50 wt% of solid phase mud, 20 wt% of silicate cement, 8 wt% of curing compound and 22 wt% of aggregate are mixed and stirred evenly to obtain oily sludge-based inorganic eco-stone raw material slurry, wherein the curing compound is a mixture of calcium oxide, magnesium oxide, calcium carbonate, silica fume and steel slag powder in a mass ratio of 10:10:25:10:45, and the aggregate is medium-coarse sand.

[0030] S4: The oily sludge-based inorganic eco-stone raw material slurry is pressed into shape at a pressing pressure of 20 MPa and a pressing time of 150 s. After pressing and molding, it is placed under standard curing conditions of 20°C and 100% humidity for 28 days to prepare the oily sludge-based inorganic eco-stone.

[0031] Example 3 This embodiment provides a method for preparing oily sludge-based inorganic eco-stone, comprising the following steps: S1: The oily sludge obtained from the oil field and dehydrated and dried is mixed with water. The oil content of the oily sludge is 8%, and the amount of water added is twice the mass of the oily sludge. The mixture is stirred evenly and allowed to stand for natural sedimentation at room temperature for 4 hours. The oil phase is separated from the liquid phase and the solid phase, and the liquid phase and solid phase oily sludge mixture slurry is collected.

[0032] S2: A demulsifier was added to the mixture of liquid and solid oily sludge. The demulsifier was a polyether demulsifier and the amount of demulsifier added was 3% of the mass of the oily sludge. The mixture was mixed and stirred evenly in a concrete mixer at a stirring speed of 80 r / min. After stirring for 15 minutes, the mixture was allowed to stand and naturally settle at room temperature for 2 hours. The solid phase sludge was collected and the oil content of the solid phase sludge was 1.41%.

[0033] S3: According to the mass percentage, 40 wt% of solid phase mud, 25 wt% of silicate cement, 10 wt% of curing compound and 25 wt% of aggregate are mixed and stirred evenly to obtain oily sludge-based inorganic eco-stone raw material slurry, wherein the curing compound is a mixture of calcium oxide, magnesium oxide, calcium carbonate, silica fume and steel slag powder in a mass ratio of 5:5:20:10:60, and the aggregate is medium-coarse sand.

[0034] S4: The oily sludge-based inorganic eco-stone raw material slurry is pressed into shape at a pressing pressure of 50 MPa and a pressing time of 70 s. After pressing and molding, the oily sludge-based inorganic eco-stone is naturally cured for 28 days to prepare the oily sludge-based inorganic eco-stone.

[0035] Example 4 This embodiment provides a method for preparing oily sludge-based inorganic eco-stone, comprising the following steps: S1: The oily sludge obtained from the oil field and dehydrated and dried is mixed with water. The oil content of the oily sludge is 8%, and the amount of water added is 3 times the mass of the oily sludge. The mixture is stirred evenly and allowed to stand for natural sedimentation at room temperature for 2 hours. The oil phase is separated from the liquid phase and the solid phase, and the liquid phase and solid phase oily sludge mixed slurry is collected.

[0036] S2: A demulsifier was added to the mixture of liquid and solid oily sludge. The demulsifier was a polyether demulsifier, and the amount of demulsifier added was 0.2% of the mass of the oily sludge. The mixture was mixed and stirred evenly in a concrete mixer at a stirring speed of 150 r / min. After stirring for 8 minutes, the mixture was allowed to stand and naturally settle at room temperature for 3 hours. The solid phase mud was collected, and the oil content of the solid phase mud was 1.53%.

[0037] S3: According to the mass percentage, 40 wt% of solid phase mud, 20 wt% of silicate cement, 10 wt% of curing compound and 30 wt% of aggregate are mixed and stirred evenly to obtain oily sludge-based inorganic eco-stone raw material slurry, wherein the curing compound is a mixture of calcium oxide, magnesium oxide, calcium carbonate, silica fume and steel slag powder in a mass ratio of 10:8:15:10:57, and the aggregate is medium-coarse sand.

[0038] S4: The oily sludge-based inorganic eco-stone raw material slurry is pressed into shape at a pressing pressure of 50 MPa and a pressing time of 80 s. After pressing and molding, the oily sludge-based inorganic eco-stone is naturally cured for 28 days to prepare the oily sludge-based inorganic eco-stone.

[0039] Comparative Example 1 This comparative example provides a method for preparing an oily sludge-based inorganic eco-stone, comprising the following steps: S1: The dehydrated and dried oily sludge obtained from the oil field is mixed with water. The oil content of the oily sludge is 8%. The amount of water added is twice the mass of the oily sludge. The mixture is stirred evenly and allowed to stand for natural sedimentation at room temperature for 3 hours. The oil phase is separated from the liquid phase and the solid phase, and the solid phase oily sludge mixed slurry is collected. The oil content of the solid phase oily sludge mixed slurry is 6.64%.

[0040] S2: In this comparative example, no demulsifier was added to observe whether the mechanical properties of the prepared inorganic eco-stone decreased.

[0041] S3: According to mass percentage, 60 wt% of solid oily sludge mixed slurry, 15 wt% of silicate cement, 5 wt% of curing compound and 20 wt% of aggregate are mixed and stirred evenly to obtain oily sludge-based inorganic eco-stone raw material slurry, wherein the curing compound is a mixture of calcium oxide, magnesium oxide, calcium carbonate, silica fume and steel slag powder in a mass ratio of 7:8:20:10:55, and the aggregate is medium-coarse sand.

[0042] S4: The oily sludge-based inorganic eco-stone raw material slurry is pressed into shape at a pressing pressure of 30 MPa and a pressing time of 100 s. After pressing and molding, it is placed under standard curing conditions of 20°C and 100% humidity for 28 days to prepare the oily sludge-based inorganic eco-stone.

[0043] The solid phase slurry collected according to Examples 1 to 4 of the present invention complies with the standard of SY / T 7301-2016.

[0044] The compressive strength, flexural strength, water absorption and dry density of the oily sludge-based inorganic eco-stones prepared in Examples 1 to 4 and Comparative Example 1 were tested. The test results are shown in Table 1 below: Table 1

[0045] As shown in Table 1, Examples 1-4 used a demulsifier to disrupt the emulsified system of the oily sludge, achieving oil-water-solid three-phase separation. The oily sludge-based inorganic eco-stone prepared using the collected solid-phase slurry of the oily sludge significantly outperformed the oily sludge-based inorganic eco-stone prepared from the oily sludge in Comparative Example 1, which was not treated with a demulsifier. On the other hand, a comparison of the data from Examples 1-3 shows that the compressive and flexural strengths of the oily sludge-based inorganic eco-stone prepared using oily sludge increased with decreasing the amount of oily sludge added and increasing the amount of Portland cement or aggregate added. However, both compressive and flexural strengths of the oily sludge-based inorganic eco-stone met the strength grade requirements of Cc50 in GB 28635-2012.

[0046] In summary, demulsifiers are used to destroy the emulsified system of oily sludge, achieving oil-water-solid three-phase separation of oily sludge. The collected solid phase slurry of oily sludge has a low oil content and meets the standard of SY / T 7301-2016, and can be used as a raw material for inorganic eco-stone. The oily sludge-based inorganic eco-stone prepared from oily sludge has excellent mechanical properties and low water absorption. It can be used in scenarios such as road construction, greening projects, and outdoor landscape design. It has a wide range of application scenarios, and the preparation method of the patent of this invention can maximize the comprehensive resource utilization of oily sludge. The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solution and inventive concept of the present invention, should be covered by the scope of protection of the present invention.

Claims

1. A method for preparing oily sludge-based inorganic eco-stone, characterized in that: The following steps are involved: S1: Mix the oily sludge and water and stir them evenly. After natural sedimentation, separate the oil phase from the liquid phase and the solid phase, and collect the liquid phase and solid phase oily sludge mixed slurry; S2: adding a demulsifier to the mixture of the liquid phase and the solid phase oily sludge, mixing and stirring, collecting the solid phase sludge after natural sedimentation; S3: mixing and stirring the solid phase slurry, silicate cement, curing compound and aggregate to obtain oily sludge-based inorganic eco-stone raw material slurry; S4: Pressing the oil-containing sludge-based inorganic eco-stone raw material slurry into shape, and curing it to prepare the oil-containing sludge-based inorganic eco-stone.

2. The method for preparing an oily sludge-based inorganic eco-stone according to claim 1, characterized in that: In S1, the amount of water added is 1 to 3 times the mass of the oily sludge, and the natural sedimentation time is 2 to 4 hours.

3. The method for preparing an oily sludge-based inorganic eco-stone according to claim 1, characterized in that: In S2, the demulsifier is a polyether demulsifier, and the amount of the demulsifier added is 0.1-3% of the mass of the oily sludge.

4. The method for preparing an oily sludge-based inorganic eco-stone according to claim 1, characterized in that: In S2, the stirring speed is 60 to 200 r / min, the stirring time is 5 to 15 min, and the natural sedimentation time is 2 to 4 h.

5. The method for preparing an oily sludge-based inorganic eco-stone according to claim 1, characterized in that: In S3, the mass ratio of the solid phase slurry, silicate cement, curing compound and aggregate is 30-60:15-30:4-15:15-30.

6. The method for preparing an oily sludge-based inorganic eco-stone according to claim 1, characterized in that: In S3, the curing compound is a mixture of calcium oxide, magnesium oxide, calcium carbonate, silica fume and steel slag powder in a mass ratio of 5-10:5-10:15-25:5-10:45-60, and the aggregate is medium-coarse sand.

7. The method for preparing an oily sludge-based inorganic eco-stone according to claim 1, characterized in that: In the step S4 , the pressing pressure is 15 to 50 MPa, and the pressing time is 70 to 150 s.

8. The method for preparing an oily sludge-based inorganic eco-stone according to claim 1, characterized in that: In S4, the curing is natural curing, and the duration is 14 to 28 days.

9. The method for preparing an oily sludge-based inorganic eco-stone according to claim 1, characterized in that: In S4, the curing is standard curing, with a temperature of 18 to 22° C., a standard curing humidity of 95 to 100%, and a standard curing time of 14 to 28 days.

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