A method and apparatus for purifying sludge sediment

Abstract

The present application relates to a kind of slurry purification method and device, belong to slurry purification technical field, by adding breaker and combining oxidation / acidolysis and thermochemical treatment, the stable structure of colloidal particle is destroyed, the microfine particle wrapped is released, further using helical path partition addition surfactant, ensure that reagent is evenly spread in combination with stirring, significantly reduce slurry apparent viscosity and improve fluidity.Afterwards, using the centrifugal-shear synergistic effect of high-speed centrifuge and hydrocyclone strengthens particle separation efficiency, shortens residence time and inhibits the risk of laminar flow blockage;While applying electric field drives charged particle to be enriched to electrode area.Finally, through the deep dehydration process of filter aid auxiliary, realize that slurry moisture content is greatly reduced, this integrated process not only reduces the hydrodynamic resistance and processing volume expansion, also significantly alleviates the laminar flow resistance, wear and frequent blockage problem of pipeline and equipment.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of mud slurry purification, and particularly relates to a mud slurry purification method and device. BACKGROUND

[0002] Mud slurry treatment is a key link in the fields of oil drilling, mining and engineering construction, and its treatment efficiency directly determines the resource recovery rate, equipment service life and environmental protection cost control level. The current mainstream technology mainly relies on a triple process system of mechanical separation, chemical flocculation and centrifugal dewatering: first, large particle solids are removed through a vibrating screen or a cyclone for primary screening; then, fine particles are aggregated into groups by adding flocculating agents to realize sedimentation separation; finally, plate and frame filter presses or centrifuges are used for pressure filtration and dewatering to reduce the water content.

[0003] However, when facing complex component mud with high oil content and strong colloidal stability, the existing technology system faces significant challenges. The stable dispersion system of colloidal particles in the mud is formed due to the surface charge repulsion effect and the protection of the hydration layer. Under the synergistic effect of oil phase wrapping and high viscosity medium, the conventional flocculation process is difficult to effectively destroy the colloidal protection layer, the release of fine particles is blocked, causing low aggregation efficiency. At the same time, the high viscosity characteristics cause the deterioration of fluid dynamics, not only expanding the treatment volume, but also forming a laminar flow blocking effect in the pipeline system and separation equipment, which significantly increases the operation and maintenance cost due to the accelerated equipment wear rate and frequent blockage problems. In view of this technical bottleneck, it is urgent to develop a new type of mud slurry purification method and device. SUMMARY

[0004] To solve the above problems in the prior art, the application provides a mud slurry purification method and device, which solves the problem of fluid dynamics deterioration caused by high viscosity mud in the prior art, not only expanding the treatment volume, but also forming a laminar flow blocking effect in the pipeline system and separation equipment, which significantly increases the operation and maintenance cost due to the accelerated equipment wear rate and frequent blockage problems.

[0005] The object of the application can be achieved by the following technical solutions:

[0006] A mud slurry purification method, comprising the following steps:

[0007] S1: first, break the colloidal stable structure, add a breaker, oxidize or acidolysis the organic matter or hydration layer on the surface of the colloid, adjust the pH to the isoelectric point, neutralize the surface charge of the particles, and then perform thermal chemical treatment to promote particle destabilization, collapse the colloidal protection layer, and release the wrapped fine particles;

[0008] S2: take the amount of slurry sample in S1, put it into an environment with a known magnetic field strength, by observing whether the particles move to the direction of the magnetic field, to determine whether it has magnetic properties, if the particles have magnetic properties, first add inorganic flocculants to neutralize the charge, then add high molecular flocculants to form large flocs through "bridging effect", if the particles have no magnetic properties, add magnetite powder as magnetic seeds to make it coagulate with the particles;

[0009] S3: reduce the viscosity of the slurry, and add surfactants to the first annular region, the second annular region and the Nth annular region in a spiral path;

[0010] S4: use a high-speed centrifuge and a hydrocyclone to separate the particles by shear force and centrifugal force;

[0011] S5: apply an electric field to the charged particles, and drive the particles to migrate directionally to the electrode area to gather;

[0012] S6: filter, and then use a filter press to perform deep dewatering.

[0013] As a further scheme of the present application, the volume V of each annular region in S3 i Decreases with the decrease of radius and decreases according to a quadratic function.

[0014] As a further scheme of the present application, after reducing the viscosity of the slurry in S3, heating is required to increase the temperature, and the temperature-viscosity negative correlation is used again to improve the fluidity.

[0015] As a further scheme of the present application, when adding surfactants to the first annular region, the second annular region and the Nth annular region in S3 in a spiral path, a radial and tangential stirrer is required to be used simultaneously.

[0016] As a further scheme of the present application, after adding surfactants to each annular region in S3, a period of time is required for the surfactants to diffuse preliminarily, and before entering the next annular region, the viscosity of the current annular region is detected to dynamically adjust the subsequent addition amount.

[0017] As a further scheme of the present application, the Nth annular region in S3 has the smallest volume, and the addition amount needs to be reduced by 10% to 15%.

[0018] The mud slurry purification device comprises a supporting cylinder, a mud-water separation assembly, a concentration dehydration assembly and a purification recovery assembly arranged in the supporting cylinder respectively, and the mud-water separation assembly, the concentration dehydration assembly and the purification recovery assembly are arranged from top to bottom in the supporting cylinder.

[0019] As a further scheme of the present application, the mud-water separation assembly, the concentration dehydration assembly and the purification recovery assembly all comprise filter screens, the mesh of the filter screens in the mud-water separation assembly, the concentration dehydration assembly and the purification recovery assembly decreases in turn, and the mesh of the adjacent two filter screens is arranged in a staggered manner.

[0020] As a further scheme of the present application, the mesh of the filter screens in the mud-water separation assembly, the concentration dehydration assembly and the purification recovery assembly is in a positive funnel structure.

[0021] The present application has the following beneficial effects:

[0022] The multi-step cooperative treatment effectively solves the separation problem of high-viscosity mud. First, a gel breaker is added, combined with oxidation / acidolysis and thermal chemical treatment, to destroy the stable structure of colloidal particles and release the wrapped fine particles. Then, the particle magnetism is determined by a magnetic field test. If it is magnetic, an inorganic coagulant and a high molecular flocculant are added to promote flocculation. If it is not magnetic, magnetite powder is introduced as a magnetic seed to realize copolymerization. Further, a spiral path is used to add a surfactant in different zones, combined with stirring to ensure uniform diffusion of the reagents, significantly reducing the apparent viscosity of the mud and improving the flowability. Thereafter, the centrifugal-shearing synergy of a high-speed centrifuge and a hydrocyclone is used to enhance the particle separation efficiency, shorten the residence time and inhibit the risk of laminar flow blockage. At the same time, an electric field is applied to drive the charged particles to the electrode area. Finally, a deep dehydration process assisted by a filter aid is used to achieve a significant reduction in the water content of the mud. This integrated process not only reduces the hydrodynamic resistance and reduces the processing volume expansion, but also significantly alleviates the problems of laminar flow resistance, wear and frequent blockage of pipelines and equipment. BRIEF DESCRIPTION OF DRAWINGS

[0023] For the convenience of those skilled in the art, the present application will be further described below with reference to the accompanying drawings.

[0024] Figure 1 The flow chart of the mud slurry purification method of the present application. DETAILED DESCRIPTION

[0025] To further illustrate the technical means and effects adopted by the present application to achieve the predetermined application purpose, the specific embodiments, structures, features and effects according to the present application are described in detail below with reference to the accompanying drawings and preferred embodiments.

[0026] Please refer to Figure 1 The present embodiment provides a mud slurry purification method, comprising the following steps:

[0027] S1: First, break the colloidal stability structure, add a breaker, oxidize or acidify the organic matter or hydration layer on the surface of the colloid, adjust the pH to the isoelectric point, neutralize the surface charge of the particles, and then perform a thermal chemical treatment, heating to 60-80°C, reducing the stability of the colloid, promoting particle destabilization, collapsing the colloidal protective layer, and releasing the encapsulated fine particles; This can neutralize the charge on the surface of the particles, reduce the stability of the colloid, and thus reduce the mutual repulsive force between the particles, making it easier for the particles to aggregate and form flocs. This helps to reduce the viscosity of the mud, preventing the formation of laminar flow stagnation effects in the pipeline and equipment;

[0028] S2: Take an appropriate amount of mud sample from S1 and place it in an environment with a known magnetic field strength. Observe whether the particles move towards the magnetic field to determine if they are magnetic. If the particles are magnetic, first add an inorganic flocculant to neutralize the charge, then add a high molecular weight flocculant to form large flocs through "bridging action". If the particles are not magnetic, add magnetite powder as a magnetic seed to make them coagulate with the particles; Convert micron-sized particles into millimeter-sized flocs to increase settling speed, reduce mud residence time in the pipeline, and reduce the risk of laminar flow;

[0029] S3: Reduce mud viscosity by adding a surfactant to disrupt the internal structure of the mud and reduce apparent viscosity. Divide the mud pit into concentric circles, with the first annular region, the second annular region, and the Nth annular region. Add surfactant to the first annular region, the second annular region, and the Nth annular region using a spiral path;

[0030] S4: Use a high-speed centrifuge and a hydrocyclone to compensate for insufficient density differences using centrifugal force, and use a hydrocyclone to separate particles through the combined action of shear force and centrifugal force; Improve separation efficiency, reduce mud residence time in equipment, and reduce the risk of laminar flow and plugging;

[0031] S5: Apply an electric field to charged particles to drive them to migrate directionally to the electrode area and aggregate; This electrophoretic separation technique can further improve particle separation efficiency, reduce the content of fine particles in the mud, and thus reduce the viscosity of the mud, reducing the risk of pipeline plugging and equipment wear;

[0032] S6: Perform filtration, then use a filter press device for deep dewatering, where the filter press device is a plate-and-frame filter press or a belt filter press, and add a filter aid for deep dewatering, which can effectively remove water from the mud, reducing the volume of the mud and reducing fluid dynamics issues during processing. At the same time, the deeply dewatered mud is easier to handle and store, reducing the risk of equipment wear and plugging.

[0033] When facing the mud with high oil content and strong colloidal stability, the existing technology system faces significant challenges. The stable dispersion system formed by the surface charge repulsion effect and the protection of the hydration layer of colloidal particles in the mud is difficult to be effectively destroyed by the conventional flocculation process under the synergistic effect of oil phase wrapping and high viscosity medium. The release of fine particles is blocked, causing low agglomeration efficiency. At the same time, the high viscosity characteristics cause the deterioration of fluid dynamics, not only expanding the treatment volume, but also forming a laminar flow blocking effect in the pipeline system and separation equipment, which significantly increases the operation and maintenance cost caused by the accelerated equipment wear rate and frequent plugging problems.

[0034] To solve the above problems, the present embodiment effectively solves the separation problem of high viscosity mud through multi-step synergistic treatment: first, add a gel breaker and combine oxidation / acidolysis and thermal chemical treatment to destroy the stable structure of colloidal particles and release the wrapped fine particles; then, determine the particle magnetism through magnetic field testing - if magnetic, add inorganic coagulant and polymer flocculant to promote flocculation; if not magnetic, introduce magnetite powder as a magnetic seed to realize copolymerization, and further use a spiral path to add surfactant in a partitioned manner, combined with stirring to ensure uniform diffusion of the reagent, significantly reducing the apparent viscosity of the mud and improving the fluidity. After that, the centrifugal-shearing synergistic effect of high-speed centrifuge and hydrocyclone is used to strengthen the particle separation efficiency, shorten the residence time and inhibit the risk of laminar flow plugging; at the same time, an electric field is applied to drive the charged particles to concentrate in the electrode area. Finally, through the deep dehydration process assisted by filter aid, the water content of the mud is greatly reduced. This integrated process not only reduces the fluid dynamics resistance and treatment volume expansion, but also significantly alleviates the problems of laminar flow blocking, wear and frequent plugging of the pipeline and equipment.

[0035] It should be noted that in S3, the addition of surfactant reduces the viscosity of the slurry, and the surfactant can reduce the surface tension of the slurry, thereby reducing its viscosity. However, if too much surfactant is added, the slurry may be excessively diluted, losing its original stability and affecting the subsequent treatment process. The amount of surfactant added needs to match the properties of the slurry to ensure the effectiveness and uniformity of the chemical reaction. In an embodiment, a method for calculating the amount of surfactant required for the scheme of the present application is given: first, test the viscosity of the slurry under different surfactant concentrations by rheometer or viscometer, draw the "viscosity-concentration" curve, and get the inflection point corresponding to the significant slowing down of the viscosity reduction rate, which is M. Then, calculate the theoretical amount of surfactant added according to the formula Q theoretical = V x p x M, where V is the volume of the slurry, Q theoretical is the theoretical amount of surfactant added, p is the density of the slurry, and M is the inflection point corresponding to the significant slowing down of the viscosity reduction rate. In addition, since spiral addition may cause local uneven mixing, a correction coefficient needs to be determined through experiments. In the laboratory, simulate the spiral addition process and measure the actual amount of surfactant Q actual required to reach the target viscosity. Calculate the mixing efficiency coefficient: k = Q theoretical / Q actual, if the stirring is sufficient, k ≈ 1.1-1.3; if the stirring is manual or the path coverage is uneven, k ≈ 1.5-2.0. Divide the slurry pool into N annular regions along the spiral path, and each region has a volume V i = V / N, then the i-th addition amount is: i Q i i = k x V i x p x M x (1 + a (η0-η)), where η is the target viscosity, η0 is the initial viscosity, and a is the viscosity correction factor, which reflects the nonlinear effect of the initial viscosity on the addition amount.

[0036] To improve the efficiency and uniformity of the slurry sediment purification process and avoid uneven and excessive use of chemicals, in an embodiment, the volume of each annular region in the first annular region, the second annular region, and the Nth annular region in S3 is i decreased with the radius and decreased according to a quadratic function. By reducing the viscosity of the slurry, the settling speed of the solid particles in the slurry can be accelerated, thereby improving the efficiency of the entire purification process. Using a spiral path to add surfactant can ensure that each annular region is uniformly treated, so that the viscosity of the slurry in the entire slurry pool is effectively reduced. According to the law of quadratic function decrease, the amount of surfactant added to each annular region can be more accurately controlled, reducing the amount of chemical agents used and reducing costs.

[0037] Since it is aimed at high-viscosity mud, the influence of external temperature is considered, so the temperature of the mud needs to be reasonably controlled to further optimize the flowability of the mud. In an embodiment, after reducing the viscosity of the mud in S3, heating is still needed to raise the temperature to 50-70 DEG C. The flowability is improved again by using the negative correlation between temperature and viscosity. There is a negative correlation between the viscosity of the mud and the temperature, that is, as the temperature rises, the viscosity of the mud will decrease. This is because the increase in temperature will cause the molecules in the mud to move faster, and the intermolecular force will weaken, so that the mud will flow more easily. Raising the temperature can accelerate the reaction speed of the chemical additives in the mud, so that they can play a role more quickly, thereby more effectively reducing the viscosity of the mud. In S3, when the surfactant is added to the first annular region, the second annular region, and the Nth annular region respectively using the spiral path, radial and tangential stirring is needed using the stirrer. The addition method of the spiral path and the radial and tangential stirring ensure the uniform distribution of the surfactant in the mud. In addition, after adding the surfactant to each annular region in S3, a period of time is needed for the surfactant to diffuse preliminarily. The period of time for the surfactant to diffuse preliminarily helps to improve its contact efficiency and reaction efficiency with the mud. If no period of time is allowed for the surfactant to diffuse preliminarily, the surfactant may not be able to fully contact the mud, thereby reducing the purification effect. Since the fixed amount of addition may cause too much or too little surfactant in some areas, affecting the purification effect and cost, the viscosity of the current region is detected before entering the next circle, and the subsequent addition amount is dynamically adjusted, so that the amount of surfactant can be accurately controlled, and waste can be avoided. Finally, the volume of the Nth annular region in S3 is the smallest, and the addition amount needs to be reduced by 10-15%. The reduction of 10-15% can maximize the cost-effectiveness on the premise of not sacrificing product performance. The reduction of the addition amount of the surfactant in the Nth annular region can reduce the cost and avoid over-treatment.

[0038] A mud sludge purification device, comprising a support cylinder, a mud-water separation assembly, a concentration and dehydration assembly, and a purification and recovery assembly arranged in the support cylinder respectively, the mud-water separation assembly, the concentration and dehydration assembly, and the purification and recovery assembly are arranged from top to bottom in the support cylinder, the mud-water separation assembly, the concentration and dehydration assembly, and the purification and recovery assembly all comprise a filter screen, the mesh size of the filter screens in the mud-water separation assembly, the concentration and dehydration assembly, and the purification and recovery assembly decreases in turn, and the mesh size of the adjacent two filter screens is arranged in a staggered manner, and the mesh size of the filter screens in the mud-water separation assembly, the concentration and dehydration assembly, and the purification and recovery assembly is a positive funnel structure.

[0039] It is worth mentioning that the filter screen of the sludge separation to the concentrated dehydration to the purification recovery assembly is gradually reduced in mesh size, forming a three-stage filtering gradient, large particles are intercepted in the first layer to avoid direct impact on the subsequent fine screen and reduce the risk of instantaneous blockage, different particle sizes are gradually trapped through physical classification, and the fine screen is prevented from being covered by large particles too early, in addition, the flow rate of viscous fluid gradually adapts to the mesh size in progressive filtration, reducing the deterioration of laminar flow caused by sudden pressure changes, while sharing the wear pressure in stages, prolonging the service life of each component; in addition, the mesh of adjacent filter screens is designed to be staggered, the mesh of adjacent filter screens does not overlap in the vertical direction, forcing the fluid path to change, inducing local turbulence through path offset, breaking the laminar flow resistance easily formed by high-viscosity fluid, enhancing the internal shear force of the slurry, and the vortex generated by the change of fluid direction can flush the edge of the mesh, preventing particles from being stuck, which can effectively alleviate the "boundary layer thickening" phenomenon of viscous slurry, reduce flow resistance, improve processing efficiency, reduce the probability of static adhesion of particles at the mesh, and inhibit blockage from the root of flow state design; finally, the filter screen of the positive funnel structure, the mesh is a reverse tapered channel with large size at the top and small size at the bottom, which uses gravity and fluid power to guide the trapped particles to slide down the funnel wall, avoiding horizontal retention, the funnel structure forms a local pressure difference, accelerating the flow through the mesh, reducing the particle residence time, the tapered channel enlarges the contact area when the particles pass through, reducing the probability of being stuck.

[0040] The above is only a preferred embodiment of the present application, and does not limit the present application in any form. Although the present application has been disclosed as above, it is not intended to limit the present application. Any person skilled in the art can make some changes or modifications to the above disclosed technical content to obtain equivalent embodiments with equivalent changes, without departing from the technical solution of the present application. Any modification, equivalent change and modification of the above embodiments made in accordance with the technical essence of the present application are still within the scope of the technical solution of the present application.

Claims

1. A method for purifying sludge sediment, characterized by, The method comprises the following steps: S1: first destroy the colloidal stability structure, add a gel breaker, oxidize or acidify the organic matter or hydration layer on the surface of the colloid, adjust the pH to the isoelectric point, neutralize the surface charge of the particles, and then perform a thermal chemical treatment to promote particle destabilization, collapse the colloidal protective layer, and release the encapsulated fine particles; S2: take an appropriate amount of slurry sample from S1 and place it in an environment with a known magnetic field strength. Observe whether the particles move towards the magnetic field to determine if they have magnetic properties. If the particles have magnetic properties, first add an inorganic flocculant to neutralize the charge, and then add a high molecular flocculant to form large flocs through "bridging action". If the particles do not have magnetic properties, add magnetite powder as a magnetic seed to make it coagulate with the particles; S3: reduce the viscosity of the slurry, and add a surfactant to the first annular region, the second annular region, and the Nth annular region in a spiral path, respectively, from the edge of the slurry tank to the center of the slurry tank; S4: use a high-speed centrifuge and a hydrocyclone to separate the particles through the combined action of shear force and centrifugal force; S5: apply an electric field to the charged particles to drive them to migrate directionally to the electrode area and aggregate; S6: filter, and then use a filter press to perform deep dewatering; In S3, after adding the surfactant to each annular region, wait for a period of time for the surfactant to diffuse preliminarily, and before moving on to the next region, detect the viscosity of the current region and dynamically adjust the subsequent addition amount. In S3, the surfactant is added to the first annular region, the second annular region, and the Nth annular region in a spiral path, and a stirrer is used for radial and tangential stirring.

2. A method of purifying sludge sediment according to claim 1, characterized in that, The volume of each annular region V of the first annular region, of the second annular region up to the Nth annular region of the S3 i decreases as the radius decreases and as a quadratic function.

3. A method of purifying sludge sediment according to claim 1, characterized in that, In S3, after reducing the viscosity of the slurry, heating is required to further improve the fluidity by utilizing the negative correlation between temperature and viscosity.

4. A method of purifying sludge sediment according to claim 1, characterized in that, The Nth annular region in S3 has the smallest volume, and the addition amount needs to be reduced by 10% to 15%.

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