A method for preparing oily sludge-based inorganic eco-stone

Abstract

A method for preparing oily sludge-based inorganic eco-stone includes the following steps: S1: Mixing oily sludge and water until homogeneous, allowing natural sedimentation to separate the oil phase from the liquid and solid phases, and collecting the mixed slurry of liquid and solid oily sludge; S2: Adding a demulsifier to the mixed slurry, mixing and stirring, allowing natural sedimentation, and collecting the solid slurry; S3: Mixing the solid slurry, silicate cement, curing compound, and aggregate until homogeneous to obtain the raw material slurry of oily sludge-based inorganic eco-stone; S4: Pressing the raw material slurry into shape, curing, and preparing the oily sludge-based inorganic eco-stone. The advantages are: the oily sludge-based inorganic eco-stone has excellent mechanical properties and low water absorption, making it suitable for road construction, landscaping projects, and outdoor landscape design, with a wide range of applications.

Description

Technical Field

[0001] This invention patent relates to the field of separation and utilization technology, specifically to a method for preparing an inorganic ecological stone based on oily sludge. Background Technology

[0002] Oily sludge is mainly oily solid waste generated during the extraction, transportation, storage and refining of petroleum. It has a complex composition, containing multiple oily substances, suspended solids and a large amount of toxic substances such as benzene and phenols, which can cause harm to human health, ecology and environment. Therefore, it has been included in the "National Hazardous Waste List".

[0003] The treatment and disposal of oily sludge must meet the development requirements of sustainable resource utilization while simultaneously achieving the dual goals of harmless disposal and resource utilization. In the application of oily sludge treatment technologies, on the one hand, the stable water-in-oil (W / O) emulsion, oil-in-water (O / W) emulsion, or complex multiple emulsion structures formed by water, oil, and solid particles in oily sludge significantly increase the difficulty of separating the oil-water-solid three-phase system. On the other hand, due to the high proportion of petroleum hydrocarbons in oily sludge and their significant environmental hazards, oily sludge treatment technologies primarily focus on the recovery of petroleum hydrocarbons from the oil phase, while the disposal of the solid phase mainly employs methods such as landfill or biological treatment, with relatively few technologies for resource utilization.

[0004] In the prior art, Chinese invention patent CN 116924648A discloses a method for treating oily sludge, which involves mixing oily sludge, demulsifier and flocculant to achieve three-phase separation to obtain water, oil and solidified oily sludge, mixing solidified oily sludge with coal-water slurry and settling to obtain oily sludge-coal-water slurry and remaining oily sludge, and then incinerating the oily sludge to convert it 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. This invention involves drying the oily sludge, adding modified diatomaceous earth as a catalyst for pyrolysis to obtain pyrolysis residue, and then mixing the pyrolysis residue, fly ash, silica fume, and cement to process it into road base concrete. Testing showed that the maximum 28-day strength of the standard concrete specimen was 44 MPa.

[0006] Most 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 within the sludge. The remaining solid phase is typically incinerated or landfilled, lacking the resource utilization of the solid phase within the oily sludge. Furthermore, the utilization of the remaining solid phase after treatment requires further processing using high-temperature pyrolysis or incineration to obtain residues or ash. However, high-temperature pyrolysis or incineration processes are complex, energy-intensive, demanding on equipment, and pose a risk of secondary pollution. Summary of the Invention

[0007] The purpose of this invention is to solve the existing technical problems by proposing a method for preparing an inorganic ecological stone based on oily sludge.

[0008] To achieve the above objectives, the present invention adopts the following technical solution: a method for preparing oily sludge-based inorganic ecological stone, comprising the following steps:

[0009] S1: Mix oily sludge and water evenly, and after natural sedimentation, separate the oil phase from the liquid phase and solid phase, and collect the mixed slurry of oily sludge in liquid and solid phases.

[0010] S2: Add a demulsifier to the mixture of liquid and solid oily sludge, mix and stir, and collect the solid sludge after natural sedimentation.

[0011] S3: Mix the solid slurry, silicate cement, curing compounding agent and aggregate evenly to obtain an oily sludge-based inorganic ecological stone raw material slurry;

[0012] S4: Press the oily sludge-based inorganic ecological stone raw material slurry into shape, and after curing, prepare oily sludge-based inorganic ecological stone.

[0013] Furthermore, in step 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.

[0014] 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.

[0015] Furthermore, in S2, the stirring speed is 60–200 r / min, the stirring time is 5–15 min, and the natural sedimentation time is 2–4 h.

[0016] Furthermore, in S3, the mass ratio of the solid slurry, silicate cement, curing compound agent, and aggregate is 30-60:15-30:4-15:15-30.

[0017] 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.

[0018] Furthermore, in step S4, the pressure for pressing is 15–50 MPa, and the pressing time is 70–150 s.

[0019] Furthermore, in S4, the maintenance is natural maintenance, lasting for 14 to 28 days.

[0020] Furthermore, in S4, the curing is standard curing, with a temperature of 18–22 °C, a humidity of 95–100%, and a curing time of 14–28 days.

[0021] The beneficial effects of the present invention are: (1) The present invention utilizes demulsifier to destroy the stable emulsion system of oily sludge, realizes the separation of oil-water-solid three phases of oily sludge, can not only recover the oil phase component of oily sludge, but also the oil content in the collected solid phase is low, which meets the standard of SY / T 7301-2016, and can be used as raw material for inorganic ecological stone, so as to maximize the comprehensive resource utilization of oily sludge.

[0022] (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 investment in process construction and low energy consumption.

[0023] (3) The inorganic ecological stone made from oily sludge prepared by this 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 exhibits excellent mechanical properties and low water absorption, making it suitable for road construction, greening projects, and outdoor landscape design, with a wide range of applications. The preparation method provided by this invention has positive guiding significance for the comprehensive resource utilization of oily sludge, and is more in line with environmental protection requirements, sustainable development concepts, and green development concepts. Attached Figure Description

[0024] Figure 1 This is a graph showing the oil content of solid mud in various embodiments of the present invention.

[0025] Figure 2 This is a physical image of the product obtained in Example 1. Detailed Implementation

[0026] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0027] Example 1 combined with appendix Figure 1-2 This embodiment provides a method for preparing inorganic eco-stone based on oily sludge, including the following steps:

[0028] S1: Oily sludge obtained from the oil field after dehydration and drying treatment, with an oil content of 8%, is mixed with water at a ratio of 2 times the mass of the oily sludge. After mixing and stirring evenly, the mixture is allowed to settle naturally at room temperature for 3 hours. The oil phase is separated from the liquid and solid phases, and the liquid and solid phases of the oily sludge mixture are collected.

[0029] S2: Add a demulsifier to the mixture of liquid and solid oily sludge. The demulsifier is a polyether demulsifier. The amount of demulsifier added is 0.5% of the mass of the oily sludge. Mix and stir evenly in a concrete mixer at a stirring speed of 150 r / min. After stirring for 5 min, let it stand naturally at room temperature for 3 h to settle. Collect the solid sludge. The oil content of the solid sludge is 1.24%.

[0030] S3: Mix 60 wt% solid mud, 15 wt% silicate cement, 5 wt% curing compound agent and 20 wt% aggregate by mass percentage to obtain an oily sludge-based inorganic ecological stone raw material slurry. The curing compound agent 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. The aggregate is medium and coarse sand.

[0031] S4: The slurry of oily sludge-based inorganic ecological stone is pressed into shape. The pressing pressure is 30 MPa and the pressing time is 100 s. After pressing, it is placed under standard curing conditions of 20 ℃ and 100% humidity for 28 days to prepare the oily sludge-based inorganic ecological stone.

[0032] Example 2

[0033] This embodiment provides a method for preparing inorganic eco-stone based on oily sludge, including the following steps:

[0034] S1: The oily sludge obtained from the oil field after dehydration and drying 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. After mixing and stirring evenly, the mixture is allowed to settle naturally at room temperature for 2 hours. The oil phase is separated from the liquid phase and the solid phase, and the mixed slurry of liquid and solid oily sludge is collected.

[0035] S2: Add a demulsifier to the mixture of liquid and solid oily sludge. The demulsifier is a polyether-based demulsifier. The amount of demulsifier added is 1% of the mass of the oily sludge. Mix and stir evenly in a concrete mixer at a stirring speed of 120 r / min. After stirring for 10 min, let it stand naturally at room temperature for 2 h to settle. Collect the solid sludge. The oil content of the solid sludge is 0.98%.

[0036] S3: Mix 50 wt% solid mud, 20 wt% silicate cement, 8 wt% curing compound agent and 22 wt% aggregate by mass percentage to obtain an oily sludge-based inorganic ecological stone raw material slurry. The curing compound agent 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. The aggregate is medium and coarse sand.

[0037] S4: The slurry of oily sludge-based inorganic ecological stone is pressed into shape. The pressing pressure is 20 MPa and the pressing time is 150 s. After pressing, it is placed under standard curing conditions of 20 ℃ and 100% humidity for 28 days to prepare the oily sludge-based inorganic ecological stone.

[0038] Example 3

[0039] This embodiment provides a method for preparing inorganic eco-stone based on oily sludge, including the following steps:

[0040] S1: The oily sludge obtained from the oil field after dehydration and drying 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. After mixing and stirring evenly, the mixture is allowed to settle naturally at room temperature for 4 hours. The oil phase is separated from the liquid phase and the solid phase, and the mixed slurry of liquid and solid oily sludge is collected.

[0041] S2: Add a demulsifier to the mixture of liquid and solid oily sludge. The demulsifier is a polyether demulsifier. The amount of demulsifier added is 3% of the mass of the oily sludge. Mix and stir evenly in a concrete mixer at a stirring speed of 80 r / min for 15 min. After stirring, let it stand naturally at room temperature for 2 h to settle. Collect the solid sludge. The oil content of the solid sludge is 1.41%.

[0042] S3: Mix 40 wt% solid mud, 25 wt% silicate cement, 10 wt% curing compound agent and 25 wt% aggregate by mass percentage to obtain an oily sludge-based inorganic ecological stone raw material slurry. The curing compound agent 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. The aggregate is medium and coarse sand.

[0043] S4: Press the slurry of oily sludge-based inorganic ecological stone into shape. The pressing pressure is 50 MPa and the pressing time is 70 s. After pressing, allow it to cure naturally for 28 days to obtain the oily sludge-based inorganic ecological stone.

[0044] Example 4

[0045] This embodiment provides a method for preparing inorganic eco-stone based on oily sludge, including the following steps:

[0046] S1: The oily sludge obtained from the oil field after dehydration and drying 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. After mixing and stirring evenly, the mixture is allowed to settle naturally at room temperature for 2 hours. The oil phase is separated from the liquid phase and the solid phase, and the mixed slurry of liquid and solid oily sludge is collected.

[0047] S2: Add a demulsifier to the mixture of liquid and solid oily sludge. The demulsifier is a polyether demulsifier. The amount of demulsifier added is 0.2% of the mass of the oily sludge. Mix and stir evenly in a concrete mixer at a stirring speed of 150 r / min for 8 min. After stirring, let it stand naturally at room temperature for 3 h to collect the solid sludge. The oil content of the solid sludge is 1.53%.

[0048] S3: Mix 40 wt% solid mud, 20 wt% silicate cement, 10 wt% curing compound agent and 30 wt% aggregate by mass percentage to obtain an oily sludge-based inorganic ecological stone raw material slurry. The curing compound agent 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. The aggregate is medium and coarse sand.

[0049] S4: Press the slurry of oily sludge-based inorganic ecological stone into shape. The pressing pressure is 50 MPa and the pressing time is 80 s. After pressing, allow it to cure naturally for 28 days to obtain the oily sludge-based inorganic ecological stone.

[0050] Comparative Example 1

[0051] This comparative example provides a method for preparing an inorganic eco-stone based on oily sludge, comprising the following steps:

[0052] S1: The oily sludge obtained from the oil field after dehydration and drying 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. After mixing evenly, it is allowed to stand naturally at room temperature for 3 hours to separate the oil phase from the liquid phase and the solid phase. The solid phase oily sludge mixture is collected, and the oil content of the solid phase oily sludge mixture is 6.64%.

[0053] S2: In this comparative example, no demulsifier was added, and the mechanical properties of the prepared inorganic eco-stone were observed to see if they decreased.

[0054] S3: By mass percentage, 60 wt% of solid oily sludge mixture, 15 wt% of silicate cement, 5 wt% of curing compound agent and 20 wt% of aggregate are mixed and stirred evenly to obtain oily sludge-based inorganic ecological stone raw material slurry. The curing compound agent is composed of calcium oxide, magnesium oxide, calcium carbonate, silica fume and steel slag powder mixed in a mass ratio of 7:8:20:10:55. The aggregate is medium and coarse sand.

[0055] S4: The slurry of oily sludge-based inorganic ecological stone is pressed into shape. The pressing pressure is 30 MPa and the pressing time is 100 s. After pressing, it is placed under standard curing conditions of 20 ℃ and 100% humidity for 28 days to prepare the oily sludge-based inorganic ecological stone.

[0056] The solid mud collected according to Examples 1-4 of the present invention conforms to the standard of SY / T 7301-2016.

[0057] The compressive strength, flexural strength, water absorption, and dry density of the oily sludge-based inorganic ecostones prepared in Examples 1-4 and Comparative Example 1 were tested. The test results are shown in Table 1 below:

[0058] Table 1

[0059]

[0060] As shown in Table 1, Examples 1-4 used demulsifiers to disrupt the emulsion system of oily sludge, achieving three-phase separation of oil, water, and solid phases. The compressive and flexural strengths of the oily sludge-based inorganic eco-stone prepared using the collected oily sludge solid phase slurry were significantly better than those of the oily sludge-based inorganic eco-stone prepared using the oily sludge-based sludge in Comparative Example 1 without demulsifier treatment. On the other hand, comparing the data from Examples 1-3, it can be seen that the compressive and flexural strengths of the oily sludge-based inorganic eco-stone prepared using oily sludge increased with decreasing oily sludge content and increasing silicate cement or aggregate content. However, both the compressive and flexural strengths of the oily sludge-based inorganic eco-stone met the strength grade requirements of Cc50 in GB 28635-2012 standard.

[0061] In summary, by using a demulsifier to disrupt the emulsified system of oily sludge, three-phase separation of oil, water, and solid phases can be achieved. The collected oily sludge solid phase has a low oil content, meeting 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 exhibits excellent mechanical properties and low water absorption, making it suitable for applications in road construction, landscaping projects, and outdoor landscape design, among other scenarios. Furthermore, the preparation method described in this invention maximizes the comprehensive resource utilization of oily sludge.

[0062] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A method for the preparation of an oil sludge based inorganic eco-stone, characterized by, Includes the following steps: S1: The oily sludge obtained from the oil field after dehydration and drying treatment 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 settle naturally at room temperature for 4 hours. The oil phase is separated from the liquid phase and the solid phase, and the liquid and solid phases of the oily sludge mixture are collected. S2: Add a demulsifier, specifically a polyether-based demulsifier, to the mixture of liquid and solid phase oily sludge. The amount of demulsifier added is 3% of the mass of the oily sludge. Mix the mixture thoroughly in a concrete mixer at a speed of 80 r / min for 15 min. After mixing, allow it to settle naturally at room temperature for 2 h. Collect the solid phase sludge, which has an oil content of 1.41%. S3: Mix 40 wt% solid mud, 25 wt% silicate cement, 10 wt% curing compound agent and 25 wt% aggregate by mass percentage to obtain oily sludge-based inorganic ecological stone raw material slurry. The curing compound agent is composed of calcium oxide, magnesium oxide, calcium carbonate, silica fume and steel slag powder mixed in a mass ratio of 5:5:20:10:

60. The aggregate is medium and coarse sand. S4: The slurry of oily sludge-based inorganic ecological stone is pressed into shape. The pressing pressure is 50 MPa and the pressing time is 70 s. After pressing, it is naturally cured for 28 days to obtain oily sludge-based inorganic ecological stone. The 28-day compressive strength of the oily sludge-based inorganic ecological stone is 58.7 MPa, the flexural strength is 10.12 MPa, and the water absorption rate is 5.30%.

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