Quick defoaming type concentrated solution for hydraulic support and preparation method of concentrated solution

Abstract

The invention belongs to the field of mining hydraulic support working solutions, and provides a rapid defoaming type concentrated solution for a hydraulic support and a preparation method of the rapid defoaming type concentrated solution. According to the invention, a collaborative design of a core-shell organic silicon-silicon dioxide-dopamine defoaming intermediate X and a water-ethylene glycol-surfactant-antirust corrosion inhibition system is adopted, and the intermediate is compounded through hydroxyl-terminated polydimethylsiloxane, hydrophobic fumed silica and 3-aminopropyltriethoxysilane to form core particles; a polydopamine shell layer formed by oxidation self-polymerization of dopamine is coated on the surface, so that the characteristics of low viscosity and easy pumping are maintained under the conditions of high solid content and high surfactant loading. The mining water-ethylene glycol working fluid solves the contradiction between the high lubrication antirust requirement and the low foam controllability requirement of the mining water-ethylene glycol working fluid and the essential contradiction between the strong interfacial film forming tendency and the rapid defoaming capability, and has wide application value in a mine hydraulic support system.

Description

Technical Field

[0001] The invention relates to the field of working fluids for mining hydraulic supports, specifically to a fast-defoaming concentrated fluid for hydraulic supports and its preparation method. Background Technology

[0002] Mine hydraulic support systems are core support equipment in fully mechanized coal mining faces. Under conditions of fluctuating rock pressure, frequent equipment start-ups and shutdowns, and high-intensity cyclic operation, the working fluid needs to provide stable lubrication, rust prevention, and power transmission functions across a wide temperature range. Mine-grade HFAE or HFAS water-based working fluids, based on water-ethylene glycol, incorporate nonionic surfactants, rust inhibitors, and corrosion inhibitors to meet lubrication and corrosion prevention requirements while maintaining low viscosity to adapt to underground pumping and rapid response needs. However, under actual working pressure and backflow conditions, the working fluid in hydraulic supports experiences high shear, high turbulence, and temperature fluctuations. The enrichment and directional arrangement of film-forming components such as surfactants and rust inhibitors at the fluid interface form a stable interfacial film, leading to the generation of a large amount of foam during circulation. The presence of foam not only reduces the volumetric efficiency and response speed of the hydraulic system but also accelerates the oxidative aging of the working fluid and damages seals, seriously affecting the safety and reliability of the hydraulic support. Therefore, developing a working fluid for mining hydraulic supports that can maintain low foaming tendency and rapid defoaming ability under conditions of high solids content and high surfactant loading is of great significance for improving the support efficiency of fully mechanized mining faces, extending equipment service life, and ensuring the safety of underground operations.

[0003] Current research on foam control in mine water-based working fluids mainly focuses on optimizing surfactant structures, compounding low-foaming lubricants, and adding organosilicon defoamers. For example, Chinese patent CN106492516A discloses a hyperbranched polyether-modified organosilicon defoamer containing simethicone oil and its preparation method. This method reduces foam generation by adjusting the polyether chain length. However, in this scheme, the organosilicon defoamer is prone to emulsification and increased particle size under high shear conditions, leading to a significant decrease in defoaming efficiency with prolonged cycle time. Furthermore, the thermal stability of the polyether chain is insufficient under high-temperature conditions, making it difficult to meet the long-term operation requirements of mine hydraulic supports at temperatures above 93.5℃. On the other hand, while the adsorption of nano-silica at the gas-liquid interface can disrupt foam stability when using hydrophobic nano-silica as a defoaming component, it suffers from poor dispersion stability and easy aggregation and sedimentation in the water-ethylene glycol system. This necessitates a large amount of dispersant to maintain suspension, but the introduction of dispersant increases the foaming tendency of the system, creating a vicious cycle of defoaming and foam stabilization. Furthermore, existing technologies lack sufficient research on the compatibility and synergistic mechanisms between defoamers and functional components such as rust inhibitors and surfactants, making it difficult to achieve precise foam control while ensuring lubrication and rust prevention performance. In particular, under harsh working conditions such as high solids load, wide temperature fluctuations, and long-term high-shear cycles faced by mine hydraulic supports, the durability and stability of defoaming performance remain key bottlenecks restricting the application of water-based working fluids. Summary of the Invention

[0004] The purpose of this invention is to provide a fast-defoaming concentrated fluid for hydraulic supports and its preparation method, which solves the problems of difficulty in controlling the rheological window of current mining water-ethylene glycol working fluid under high solid content, high surfactant and rust inhibitor load conditions, limited ability to maintain low foam volume and fast defoaming under normal and high shear cycle conditions, and the inherent conflict between the natural foaming and stabilizing tendency brought about by high lubrication and rust prevention functions and strong interfacial film formation tendency and the requirement for foam controllability in long-term operation of downhole hydraulic support systems in a wide temperature range.

[0005] This invention achieves a synergistic effect of stable dispersion and shear resistance durability of the defoaming component in a water-ethylene glycol matrix through the structural design of a core-shell organosilicon-silica-dopamine defoaming intermediate X. The core particles are formed by the condensation of hydroxyl-terminated polydimethylsiloxane and hydrophobic fumed silica through 3-aminopropyltriethoxysilane to create an organic-inorganic hybrid structure, combining the low surface tension of organosilicon with the rigid framework of silica. The polydopamine shell covering the surface provides steric hindrance and hydrophilicity regulation through hydrogen bonding of catechol groups and π-π stacking, which inhibits the aggregation of core particles while enhancing their redispersibility under high shear conditions. This allows the defoaming intermediate to migrate rapidly to the gas-liquid interface and effectively reduce the mechanical strength of the foam film, thereby achieving rapid defoaming and low foam stability over a wide temperature range while maintaining the low viscosity and pumpability of the system.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A concentrated fluid for a rapid defoaming hydraulic support, comprising, by total mass:

[0008] 10–40 wt% ethylene glycol;

[0009] 5–25 wt% of a fatty alcohol polyoxyethylene ether nonionic surfactant, wherein the number of oxyethylene addition of the fatty alcohol polyoxyethylene ether nonionic surfactant is 5–10.

[0010] 1–10 wt% sodium petroleum sulfonate rust inhibitor;

[0011] The solid matter of the core-shell organosilicon-silica-dopamine defoaming intermediate X accounts for 0.2–2 wt% of the total mass of the concentrate, wherein the 0.1–2 wt% is based on the mass of the solid matter in the core-shell organosilicon-silica-dopamine defoaming intermediate X. The core-shell organosilicon-silica-dopamine defoaming intermediate X is an organosilicon-silica core particle obtained by condensation and composite of hydroxyl-terminated polydimethylsiloxane, hydrophobic fumed silica and 3-aminopropyltriethoxysilane. The core-shell composite particles are formed by the oxidation and self-polymerization of dopamine hydrochloride on the surface of the core particles under alkaline conditions regulated by tris(hydroxymethyl)aminomethane to form a polydopamine shell.

[0012] 0.5–10 wt% boric acid or borate corrosion inhibitor;

[0013] And the remainder is water.

[0014] Furthermore, the core-shell organosilicon-silica-dopamine defoaming intermediate X is prepared through the following steps:

[0015] A1. Raw material preparation: Weigh the raw materials according to the following proportions: 100-150 parts by weight of hydroxyl-terminated polydimethylsiloxane, 5-30 parts by weight of hydrophobic fumed silica, 1-10 parts by weight of 3-aminopropyltriethoxysilane, 50-150 parts by weight of ethanol, 10-50 parts by weight of deionized water, 1-10 parts by weight of dopamine hydrochloride, and 1-10 parts by weight of tris(hydroxymethyl)aminomethane.

[0016] A2. Organosilicon-silica composite: Under an inert atmosphere, hydroxyl-terminated polydimethylsiloxane is mixed with ethanol and deionized water, and stirred at 60–90°C for 1–3 h. Hydrophobic fumed silica and 3-aminopropyltriethoxysilane are slowly added while stirring, and the reaction is continued at 80–100°C under reflux and condensation conditions for 2–6 h to obtain organosilicon-silica composite slurry.

[0017] A3. Dopamine Coating: The composite slurry obtained in step A2 is cooled to a temperature of 20–35°C. The dopamine hydrochloride and the tris(hydroxymethyl)aminomethane are added in an air atmosphere. The pH of the system is adjusted to 8.0–9.5 with sodium hydroxide or hydrochloric acid. The mixture is stirred at a temperature of 20–35°C for 4–12 hours to allow dopamine to undergo oxidative self-polymerization and deposit on the surface of the composite slurry particles under alkaline and dissolved oxygen conditions.

[0018] A4. Concentration and Drying: The dispersion obtained in step A3 is subjected to reduced pressure to remove most of the ethanol and water, and then vacuum dried at a temperature of 40–80°C for 4–12 h to obtain a core-shell organosilicon-silica-dopamine defoaming intermediate X solid with an average particle size of 80–200 nm. The average particle size is preferably expressed as the median particle size measured by a dynamic light scattering particle size analyzer.

[0019] Furthermore, in step A1, the specific surface area of ​​the hydrophobic fumed silica is 150–300 m² / g, and the kinematic viscosity of the hydroxyl-terminated polydimethylsiloxane at a temperature of 25°C is 500–1500 mm² / s.

[0020] Furthermore, in the core-shell organosilicon-silica-dopamine defoaming intermediate X particles obtained after step A3, the polydopamine shell layer accounts for 1–10 wt% of the total solid mass of intermediate X.

[0021] Furthermore, the solid content of the core-shell organosilicon-silica-dopamine defoaming intermediate X in the concentrate is 0.2–2.0 wt%, and the kinematic viscosity of the concentrate at a temperature of 40°C is 20–80 mm² / s, wherein the kinematic viscosity is determined according to the national standard method for testing the kinematic viscosity of lubricating oil.

[0022] Furthermore, the fatty alcohol polyoxyethylene ether nonionic surfactant is C 12 –C 14 Fatty alcohol polyoxyethylene ether, wherein the number of oxyethylene addition of the nonionic surfactant in the fatty alcohol polyoxyethylene ether is 5–10;

[0023] The effective active ingredient in the sodium petroleum sulfonate rust inhibitor comprises 1–6 wt% of the total mass of the concentrate.

[0024] The boric acid or borate corrosion inhibitor has a mass fraction of 0.5–5 wt%.

[0025] Furthermore, when the working solution obtained by diluting the concentrate with water to 3–5 wt% is subjected to a standard foam test according to the Roche foam test method specified in GB / T 13173-2008 at temperatures of 24℃ and 93.5℃, the foam volume obtained under each temperature condition is not greater than 50 mL, and the foam volume drops to not greater than 10 mL within 10 seconds after foaming stops.

[0026] As a concept of this invention, the present invention employs a synergistic design of a core-shell organosilicon-silica-dopamine defoaming intermediate X and a water-ethylene glycol-surfactant-rust and corrosion inhibitor system, primarily used to enhance the rapid defoaming performance and dispersion stability of the working fluid of mining hydraulic supports under wide temperature range and high shear cycle conditions. The core-shell structure design allows the defoaming component to maintain low surface tension and interfacial spreading ability, while the steric hindrance effect and hydrophilicity regulation of the polydopamine shell inhibit the aggregation and sedimentation of organosilicon-silica core particles in high-solids systems, significantly improving the redispersibility and long-term stability of the defoaming intermediate under shear conditions. The low surface tension provided by hydroxyl-terminated polydimethylsiloxane enables the defoaming intermediate to rapidly migrate to the gas-liquid interface and reduce the surface tension gradient of the foam film. The rigid framework of hydrophobic gas-phase silica enhances the mechanical strength and anti-emulsification ability of the core particles. 3-aminopropyltriethoxysilane acts as a coupling agent, firmly binding organosilicon and silica through siloxane bonds to form a stable organic-inorganic hybrid structure. The polydopamine shell forms a dense, hydroxyl-rich hydrophilic layer on the surface of the core particles through multiple hydrogen bonds of catechol groups and π-π stacking effect. This not only improves the dispersion uniformity of the defoaming intermediate in the water-ethylene glycol system, but also regulates the arrangement of interfacial components through hydrogen bond interactions with surfactants and rust inhibitors, reducing the accumulation of foaming precursors. Thus, it can maintain low foaming tendency and rapid defoaming ability even under high surfactant and rust inhibitor loads, achieving a comprehensive balance of lubrication, rust prevention and low foaming performance under harsh working conditions.

[0027] This invention also discloses a method for preparing a concentrated solution for a rapid defoaming hydraulic support, comprising the following steps:

[0028] S1. Matrix premixing: Ethylene glycol, water, the fatty alcohol polyoxyethylene ether nonionic surfactant, the sodium petroleum sulfonate rust inhibitor, and boric acid or borate corrosion inhibitor added according to the mass fraction range of claim 1 when selected, are added to a reaction vessel equipped with stirring and heating functions. The mixture is stirred for 30–90 min at a temperature of 40–70°C to obtain a homogeneous matrix mixture, wherein the mass ratio of ethylene glycol to water is 1:0.5–1:7.0, and the pH value of the system is adjusted to 7.0–9.0 with sodium hydroxide or hydrochloric acid.

[0029] S2. Adding defoaming intermediate X: Under conditions of temperature of 30–60°C and under stirring or shearing conditions, the core-shell organosilicon-silica-dopamine defoaming intermediate X, which exists in the form of a dispersion with a solid content of 50–80 wt%, is slowly added to the matrix mixture at a ratio of 0.1–5 wt% of the solid matter in the core-shell organosilicon-silica-dopamine defoaming intermediate X to the total mass of the obtained concentrate. The shearing time is 10–30 min, to obtain a concentrate semi-finished product containing the dispersion defoaming intermediate X.

[0030] S3. Degassing and Filtration: The concentrated semi-finished product obtained in step S2 is subjected to degassing under reduced pressure, and then filtered to obtain the concentrated product for the rapid defoaming hydraulic support.

[0031] Furthermore, the shearing device used in step S2 is a high-shear disperser;

[0032] When the preparation method is carried out continuously for three or more batches, the kinematic viscosity of the concentrate obtained in each batch at a temperature of 40°C deviates from the arithmetic mean of the kinematic viscosity of each batch by no more than ±10%.

[0033] Furthermore, when the working fluid prepared by the concentrated solution obtained by the method is mixed with water at a mass fraction of 3–5 wt% and used in the mine hydraulic support system for 7 days, the foam volume measured under the standard foam test method specified in GB / T13173-2008 at temperatures of 24℃ and 93.5℃ is no greater than 50 mL at each temperature, and the foam volume within 10 seconds after foaming stops is no greater than 15 mL.

[0034] Furthermore, the concentrated fluid for the rapid defoaming hydraulic support is used in the preparation of mining HFAE or HFAS type working fluids and in the application of the working fluids in mine hydraulic support systems. The working fluid is an HFAE or HFAS type working fluid obtained by diluting the concentrated fluid with water to 3–5 wt%. While providing lubrication and rust prevention functions under the actual working pressure and reflux conditions of the hydraulic support, when the standard foam test is conducted according to the Roche foam test method specified in GB / T 13173-2008 at temperatures of 24℃ and 93.5℃, the foam volume is controlled to be no more than 50 mL, and the foam volume is no more than 15 mL within 10 seconds after foaming stops.

[0035] Furthermore, after the working fluid has been running continuously for 7 days, when a standard foam test is conducted according to the Roche foam test method specified in GB / T 13173-2008 at temperatures of 24℃ and 93.5℃ respectively, the increase in the measured foam volume relative to the foam volume before continuous operation shall not exceed 20mL, and the foam volume within 10s after foaming stops shall not exceed 15mL.

[0036] Further in step A3 of preparing the core-shell organosilicon-silica-dopamine defoaming intermediate X, the tris(hydroxymethyl)aminomethane can be used as a pH adjuster to adjust the system to alkalinity, thereby promoting the oxidative self-polymerization of dopamine on the surface of organosilicon-silica composite particles to form a relatively dense polydopamine shell, thereby improving the dispersion stability and shear resistance of the defoaming intermediate in the water-ethylene glycol system.

[0037] Furthermore, in one embodiment, in step A2, the reaction time is controlled to form Si-O-Si bonds between the silica surface and hydroxyl-terminated polydimethylsiloxane, thereby limiting the mass fraction of silica in the organosilicon-silica composite slurry to 5–15 wt%, in order to achieve a balance between defoaming efficiency and system transparency.

[0038] Furthermore, in one embodiment, after step A3, the core-shell organosilicon-silica-dopamine defoaming intermediate X particles are obtained. After centrifugation or filtration, the resulting wet solid is washed 1–3 times with water or an ethanol-water mixed solvent, and then subjected to vacuum drying according to step A4. This allows the total mass of residual unreacted dopamine hydrochloride, 3-aminopropyltriethoxysilane, and tris(hydroxymethyl)aminomethane in the intermediate X to be controlled at a low level, for example, not more than 0.5 wt%, thereby reducing potential adverse effects on hydraulic system metal parts and seals.

[0039] Furthermore, in one embodiment, the intermediate X solid obtained in step A4 is dispersed in water and adjusted to obtain a core-shell organosilicon-silica-dopamine defoaming intermediate X dispersion with a solid content of 50–80 wt%, so as to achieve metering accuracy and uniform addition in the industrial solution preparation process.

[0040] Furthermore, in the above-mentioned concentrate, the fatty alcohol polyoxyethylene ether nonionic surfactant may optionally be limited to C 12 –C 14 Fatty alcohol polyoxyethylene ether with an oxyethylene addition number of 5–10 is used to reduce the tendency of foam formation under high temperature conditions while ensuring lubrication and cleaning performance.

[0041] Furthermore, in one embodiment, the effective active ingredient in the commercial sodium petroleum sulfonate rust inhibitor preferably accounts for 1–6 wt% of the total mass of the concentrate, and is compounded with 0.5–5 wt% of boric acid or borate corrosion inhibitor to improve the rust prevention performance and pitting corrosion inhibition capability of steel materials in an aqueous working fluid environment.

[0042] Furthermore, in this preparation method, step S2 preferably uses a high-shear disperser with a shear speed of 2000–6000 r / min to shear disperse the defoaming intermediate X dispersion. The particle size distribution of intermediate X in the concentrate is controlled by adjusting the shear time and shear intensity, so as to improve the rapid defoaming ability of the working liquid under high shear reflux conditions.

[0043] Furthermore, based on the above technical solution, when the preparation process is carried out in three or more batches, the deviation of the kinematic viscosity of each batch of concentrate at 40°C from the arithmetic mean of the kinematic viscosity of each batch can be controlled within ±10% through online or offline viscosity detection and process parameter feedback control, thereby ensuring the consistency of the working fluid performance when replenishing and replacing it on-site in the mine.

[0044] Furthermore, in one embodiment, after the working solution prepared by mixing the above-mentioned concentrate with water at a mass fraction of 3–5 wt% is continuously sheared for 4 hours (for example, by shearing with a high-shear stirring device under a preset shear speed), and then subjected to a standard foam test again according to the Roche foam test method specified in GB / T 13173-2008, the foam volume measured at 24℃ and 93.5℃ can be controlled within the range of no more than 50 mL and no more than 15 mL within 10 seconds after foaming stops, so as to reflect the stability of the defoaming performance of the working solution under long-term cyclic conditions.

[0045] Furthermore, in another embodiment, the working fluid is used in a mine hydraulic support system for continuous operation under high shear cycle conditions caused by rock pressure fluctuations.

[0046] As another aspect of this invention, a matrix premixing-high shear dispersion-defoaming filtration process is employed, primarily to enhance the dispersion uniformity and batch stability of core-shell organosilicon-silica-dopamine defoaming intermediate X in a high-solids-content concentrate system. The matrix premixing step establishes a suitable rheological window for defoaming intermediate dispersion by controlling the mass ratio of ethylene glycol to water and the system pH. The thorough dissolution and uniform distribution of surfactants and rust inhibitors during the premixing stage provide a stable matrix environment for the subsequent addition of the defoaming intermediate, preventing agglomeration and sedimentation of the defoaming components due to excessive local concentration gradients. The high-shear dispersion step, by controlling the shear time and shear intensity, performs secondary dispersion and particle size optimization of the defoaming intermediate X added in dispersion form within the matrix. This breaks down any potential soft agglomerates, resulting in a more uniform particle size distribution and improved redispersibility and shear resistance during working solution dilution and recycling. The defoaming and filtration steps remove air bubbles and mechanical impurities introduced during the preparation process, ensuring the transparency and storage stability of the final concentrate. By using online or offline viscosity monitoring and feedback control, the kinematic viscosity of each batch of concentrate produced continuously is kept highly consistent, with the relative deviation controlled within ±10%. This ensures the stability and traceability of the working fluid performance during on-site replenishment and replacement in the mine, and meets the stringent requirements of the hydraulic support system for long-term continuous operation of the working fluid.

[0047] In this invention, the synergistic effect of hydroxyl-terminated polydimethylsiloxane and hydrophobic fumed silica is reflected in the optimized balance between defoaming efficiency and dispersion stability. Hydroxyl-terminated polydimethylsiloxane, as the core defoaming component, possesses low surface tension, enabling it to spread rapidly on the foam film surface and reduce the film's mechanical strength, primarily contributing to improved interfacial spreading performance and rapid defoaming ability. Hydrophobic fumed silica, as a rigid filler, with its high specific surface area and nanoscale particle size, can form a wedging effect in the foam film and disrupt its continuity, primarily contributing to enhanced anti-emulsification ability and defoaming durability. During the organosilicon-silica composite process, the terminal hydroxyl groups of the hydroxyl-terminated polydimethylsiloxane and the silanol groups on the surface of the hydrophobic fumed silica form Si-O-Si covalent bonds mediated by 3-aminopropyltriethoxysilane, constructing an organic-inorganic hybrid interface that firmly bonds the flexible organosilicon segments to the rigid silica framework. This hybrid structure retains the low surface tension and interfacial activity of organosilicon while acquiring the mechanical strength and shear resistance of silica, making it less prone to emulsification and particle size enlargement under high shear conditions. The introduction of the polydopamine shell further enhances the synergistic effect of the two, anchoring organosilicon and silica in the core-shell structure through the hydrogen bond network of catechol groups, inhibiting the precipitation of organosilicon and the aggregation of silica, and maintaining the defoaming intermediate in a nanoscale dispersion state in the water-ethylene glycol system. This achieves a synergistic improvement in rapid defoaming ability and dispersion stability under wide temperature range and long cycle conditions.

[0048] Beneficial technical effects

[0049] 1. Significantly improves rapid defoaming performance over a wide temperature range: Through the structural design of core-shell organosilicon-silica-dopamine defoaming intermediate X, combined with the low surface tension characteristics of hydroxyl-terminated polydimethylsiloxane and the wedge-breaking effect of hydrophobic fumed silica, the foaming volume of the working fluid after dilution of the concentrate is controlled within 50mL in a wide temperature range of 24℃ and 93.5℃. Moreover, the foam volume rapidly drops to less than 10mL within 10 seconds after foaming stops. This effectively solves the technical problem of difficult foam control in the working fluid of mining hydraulic supports under high temperature conditions, ensuring the volumetric efficiency and response speed of the hydraulic system.

[0050] 2. Enhanced defoaming durability under high shear cycling conditions: The polydopamine shell forms a dense and hydroxyl-rich hydrophilic layer on the surface of the core particles through multiple hydrogen bonding and π-π stacking effects of catechol groups. This significantly improves the redispersibility and antiemulsification properties of the defoaming intermediate under high shear conditions, enabling the working fluid to maintain a stable defoaming effect even after continuous circulation in the mine hydraulic support system for 7 days. The foam volume increases by no more than 20 mL, and the foam volume can still be reduced to less than 15 mL within 10 seconds, achieving long-term stability of defoaming performance.

[0051] 3. Achieving a synergistic balance between lubrication, rust prevention, and low foaming performance: By using a core-shell structure to encapsulate and disperse the defoaming components, while maintaining a high loading of 5–25 wt% fatty alcohol polyoxyethylene ether nonionic surfactant and 1–10 wt% sodium petroleum sulfonate rust inhibitor, the strong foaming tendency caused by the enrichment of surfactants and rust inhibitors at the interface is avoided. This allows the concentrate to maintain low foaming characteristics while meeting lubrication and rust prevention requirements, thus resolving the essential contradiction between high lubrication and rust prevention functions and low foaming controllability.

[0052] 4. Maintaining low viscosity and easy pumpability: The nanoscale dispersion of the core-shell organosilicon-silica-dopamine defoaming intermediate X and the steric hindrance effect of the polydopamine shell inhibit the aggregation and sedimentation of the defoaming components, keeping the kinematic viscosity of the concentrate within the range of 20–80 mm² / s at 40℃. This meets the rheological requirements of the mine hydraulic support system for low viscosity and easy pumpability of the working fluid, and adapts to the rapid response requirements under high solids load conditions underground.

[0053] 5. Improve batch stability and process controllability: Through the preparation process of matrix premixing-high shear dispersion-defoaming filtration, combined with online viscosity monitoring and feedback control, the relative deviation of kinematic viscosity of each batch of concentrate produced continuously is controlled within ±10% under 40℃ conditions. This ensures the consistency and traceability of working fluid performance when replenishing and replacing at the mine site, and reduces the risk of failure of hydraulic support system caused by fluctuations in working fluid performance. Attached Figure Description

[0054] Figure 1 The following are the DLS particle size distribution curves for Examples 1 to 4 and Comparative Example 10.

[0055] Figure 2 The bar chart shows the PDI of Examples 1 to 4 and Comparative Example 10.

[0056] Figure 3 The TGA TG curves are for Examples 1 to 4 and Comparative Example 10.

[0057] Figure 4 The TGA DTG curves are for Examples 1 to 4 and Comparative Example 10.

[0058] Figure 5 The figures show the volume-time curves of Roche foam as a function of time for Example 1 and Comparative Example 8 at 24°C and 93.5°C.

[0059] Figure 6 The bar chart shows the foaming volume of Examples 1 to 4 and Comparative Example 8 at 24°C and 93.5°C.

[0060] Figure 7 The bar chart shows the foam volume of Examples 1 to 4 and Comparative Example 8 at 24°C and 93.5°C for 10 s.

[0061] Figure 8 The table shows the Zeta potential histograms for Examples 1 to 4 and Comparative Example 10 at approximately pH 8 and 25°C.

[0062] Figure 9 The Zeta-pH curves for Example 1 and Comparative Example 10 show the change of Zeta potential with pH in the pH range of 6.5 to 9.0. Detailed Implementation

[0063] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings.

[0064] Example 1

[0065] A fast-defoaming hydraulic support concentrate, by total mass, comprises 25 wt% ethylene glycol and 15 wt% C. 12 –C 14The product consists of a fatty alcohol polyoxyethylene ether nonionic surfactant, 5.5 wt% sodium petroleum sulfonate rust inhibitor, 1.0 wt% core-shell organosilicon-silica-dopamine defoaming intermediate X (solid matter comprising 1.0 wt% of the total concentrated liquid), 3 wt% boric acid corrosion inhibitor, and the balance being water, totaling 100 wt%. This embodiment, C... 12 –C 14 The number of oxyethylene addition of the fatty alcohol polyoxyethylene ether nonionic surfactant is 7. In this embodiment, the effective active ingredient in the commercial sodium petroleum sulfonate rust inhibitor accounts for 3.3 wt% of the total mass of the concentrate.

[0066] The core-shell organosilicon-silica-dopamine defoaming intermediate X of this embodiment was prepared by the following steps: 125 parts by weight of hydroxyl-terminated polydimethylsiloxane, 17.5 parts by weight of hydrophobic fumed silica, 5.5 parts by weight of 3-aminopropyltriethoxysilane, 100 parts by weight of ethanol, 30 parts by weight of deionized water, 5.5 parts by weight of dopamine hydrochloride, and 5.5 parts by weight of tris(hydroxymethyl)aminomethane were weighed. Under an inert atmosphere protected by nitrogen, the hydroxyl-terminated polydimethylsiloxane was mixed with ethanol and deionized water and stirred at 75°C for 2 hours. Under stirring, the hydrophobic fumed silica and 3-aminopropyltriethoxysilane were slowly added, and the reaction was continued at 95°C under reflux condensation for 4 hours to obtain the organosilicon-silica composite slurry. The composite slurry was cooled to 27°C, and dopamine hydrochloride and tris(hydroxymethyl)aminomethane were added under air atmosphere. The pH of the system was adjusted to 8.7 with sodium hydroxide, and the mixture was stirred at 27°C for 8 hours to allow dopamine to undergo oxidative self-polymerization and deposit on the surface of the composite slurry particles under alkaline and dissolved oxygen conditions. Most of the ethanol and water in the resulting dispersion were removed under reduced pressure, and the mixture was vacuum dried at 60°C for 8 hours to obtain a core-shell organosilicon-silica-dopamine defoaming intermediate X solid with an average particle size of 140 nm. The average particle size was expressed as the volume median particle size measured by a dynamic light scattering particle size analyzer. The hydrophobic fumed silica used in this example had a specific surface area of ​​225 m² / g, and the kinematic viscosity of the hydroxyl-terminated polydimethylsiloxane at 25°C was 1000 mm² / s. In the core-shell organosilicon-silica-dopamine defoaming intermediate X particles prepared in this embodiment, the polydopamine shell layer accounts for 5.5 wt% of the total solid mass of intermediate X.

[0067] The concentrated solution preparation method of this embodiment includes the following steps: 25 kg of ethylene glycol, 50.5 kg of water, and 15 kg of C... 12 –C 14Fatty alcohol polyoxyethylene ether nonionic surfactant, 5.5 kg of commercial sodium petroleum sulfonate rust inhibitor, and 3 kg of boric acid corrosion inhibitor were added to a reactor equipped with stirring and heating functions. The mixture was stirred at 55℃ for 60 min to obtain a homogeneous matrix mixture, wherein the mass ratio of ethylene glycol to water was 1:2.0. The pH of the system was adjusted to 8.0 with sodium hydroxide. A core-shell organosilicon-silica-dopamine defoaming intermediate X was dispersed in water to prepare a dispersion with a solid content of 65 wt%. At 45℃, using a high-shear disperser at a shear speed of 4000 r / min, this dispersion was slowly added to the matrix mixture at a ratio of 1.0 wt% of the solid content of intermediate X to the total mass of the resulting concentrate. The shearing time was 20 min, yielding a semi-finished concentrate containing the dispersing defoaming intermediate X. The semi-finished concentrate was subjected to degassing under reduced pressure and then filtered to obtain a finished concentrate for rapid defoaming hydraulic supports. The concentrated solution prepared in this embodiment has a kinematic viscosity of 50 mm² / s at a temperature of 40°C. The kinematic viscosity was determined according to the national standard test method for kinematic viscosity of lubricating oil.

[0068] The concentrate of this embodiment was diluted with water to a mass fraction of 4 wt% to obtain the working solution. When standard foam tests were conducted according to the Roche foam test method specified in GB / T 13173-2008 at temperatures of 24℃ and 93.5℃, the foam volume obtained at 24℃ was 38 mL, and the foam volume decreased to 6 mL within 10 seconds after foaming stopped. At 93.5℃, the foam volume obtained was 42 mL, and the foam volume decreased to 7 mL within 10 seconds after foaming stopped. After circulating the working solution in a mine hydraulic support system for 7 days, when standard foam tests were conducted according to the Roche foam test method specified in GB / T 13173-2008 at temperatures of 24℃ and 93.5℃, the foam volume measured at 24℃ was 45 mL, and the foam volume measured at 93.5℃ was 48 mL. The foam volume within 10 seconds after foaming stopped in both cases was no greater than 9 mL.

[0069] This embodiment uses a moderate parameter configuration; the ethylene glycol content of 25wt% provides good low-temperature fluidity and moderate viscosity. 12 –C 14The fatty alcohol polyoxyethylene ether content of 15wt% and the ethylene oxide addition number of 7 achieve a balance between lubrication and defoaming performance. The solid content of intermediate X of 1.0wt% is within the preferred range to ensure a stable and rapid defoaming effect. The boric acid content of 3wt% provides reliable corrosion inhibition protection. The kinematic viscosity of the concentrate of 50mm² / s is suitable for the delivery and circulation requirements of most hydraulic systems. The combination of hydrophobic fumed silica with a specific surface area of ​​225m² / g and hydroxyl-terminated polydimethylsiloxane with a kinematic viscosity of 1000mm² / s enables intermediate X to achieve an average particle size of 140nm. The polydopamine shell content of 5.5wt% provides good dispersion stability. The working fluid exhibits excellent rapid defoaming performance under both room temperature and high temperature conditions, and its performance remains stable after 7 days of repeated use. This embodiment is applicable to conventional mine hydraulic support systems, with an ambient temperature range of -15℃ to 40℃ and a working pressure of 30-40MPa. It is suitable for fully mechanized mining faces with a coal seam dip angle of less than 25 degrees and a working face length of 150-250m, and for application scenarios where the system cleanliness requirement is NAS 1638 level 8-9.

[0070] Example 2

[0071] A fast-defoaming hydraulic support concentrate, by total mass, comprises 15 wt% ethylene glycol and 8 wt% C 12 –C 14 The concentrate contains: fatty alcohol polyoxyethylene ether nonionic surfactant, 3 wt% sodium petroleum sulfonate rust inhibitor, 1.8 wt% core-shell organosilicon-silica-dopamine defoaming intermediate X (solid matter comprising 1.8 wt% of the total concentrate mass), 1.5 wt% sodium borate corrosion inhibitor, and the balance being water, totaling 100 wt%. This embodiment, C... 12 –C 14 The number of oxyethylene addition of the fatty alcohol polyoxyethylene ether nonionic surfactant is 6. In this embodiment, the effective active ingredient in the commercial sodium petroleum sulfonate rust inhibitor accounts for 1.8 wt% of the total mass of the concentrate.

[0072] The core-shell organosilicon-silica-dopamine defoaming intermediate X of this embodiment was prepared by the following steps: 110 parts by weight of hydroxyl-terminated polydimethylsiloxane, 23 parts by weight of hydrophobic fumed silica, 3 parts by weight of 3-aminopropyltriethoxysilane, 70 parts by weight of ethanol, 20 parts by weight of deionized water, 7 parts by weight of dopamine hydrochloride, and 7 parts by weight of tris(hydroxymethyl)aminomethane were weighed. Under an inert atmosphere protected by nitrogen, the hydroxyl-terminated polydimethylsiloxane was mixed with ethanol and deionized water and stirred at 65°C for 1.5 h. Under stirring, the hydrophobic fumed silica and 3-aminopropyltriethoxysilane were slowly added, and the reaction was continued at 85°C under reflux condensation for 3 h to obtain the organosilicon-silica composite slurry. The composite slurry was cooled to 25°C, and dopamine hydrochloride and tris(hydroxymethyl)aminomethane were added under air atmosphere. The pH of the system was adjusted to 9.0 with sodium hydroxide, and the mixture was stirred at 25°C for 10 hours to allow dopamine to undergo oxidative self-polymerization and deposit on the surface of the composite slurry particles under alkaline and dissolved oxygen conditions. Most of the ethanol and water in the resulting dispersion were removed under reduced pressure, and the mixture was vacuum dried at 50°C for 10 hours to obtain a core-shell organosilicon-silica-dopamine defoaming intermediate X solid with an average particle size of 110 nm. The average particle size was expressed as the volume median particle size measured by a dynamic light scattering particle size analyzer. The hydrophobic fumed silica used in this example had a specific surface area of ​​260 m² / g, and the kinematic viscosity of the hydroxyl-terminated polydimethylsiloxane at 25°C was 650 mm² / s. In the core-shell organosilicon-silica-dopamine defoaming intermediate X particles prepared in this embodiment, the polydopamine shell layer accounts for 7 wt% of the total solid mass of intermediate X.

[0073] The concentrated solution preparation method of this embodiment includes the following steps: 15 kg of ethylene glycol, 70.7 kg of water, and 8 kg of C... 12 –C 14Fatty alcohol polyoxyethylene ether nonionic surfactant, 3 kg of commercial sodium petroleum sulfonate rust inhibitor, and 1.5 kg of sodium borate corrosion inhibitor were added to a reactor equipped with stirring and heating functions. The mixture was stirred at 50℃ for 45 min to obtain a homogeneous matrix mixture, wherein the mass ratio of ethylene glycol to water was 1:4.7. The pH of the system was adjusted to 7.5 with hydrochloric acid. A core-shell organosilicon-silica-dopamine defoaming intermediate X was dispersed in water to prepare a dispersion with a solid content of 72 wt%. At 40℃, using a high-shear disperser at a shear speed of 5200 r / min, the dispersion was slowly added to the matrix mixture at a ratio of 1.8 wt% of the solid content of intermediate X to the total mass of the resulting concentrate. The shearing time was 25 min, yielding a semi-finished concentrate containing the dispersing defoaming intermediate X. The semi-finished concentrate was subjected to degassing under reduced pressure and then filtered to obtain a finished concentrate for rapid defoaming hydraulic supports. The concentrated solution prepared in this embodiment has a kinematic viscosity of 35 mm² / s at a temperature of 40°C. The kinematic viscosity was determined according to the national standard test method for kinematic viscosity of lubricating oil.

[0074] The concentrate of this embodiment was diluted with water to a mass fraction of 3.5 wt% to obtain the working solution. When standard foam tests were conducted according to the Roche foam test method specified in GB / T 13173-2008 at temperatures of 24℃ and 93.5℃, the foam volume obtained at 24℃ was 32 mL, and the foam volume decreased to 4 mL within 10 seconds after foaming stopped. At 93.5℃, the foam volume was 36 mL, and the foam volume decreased to 5 mL within 10 seconds after foaming stopped. After circulating the working solution in a mine hydraulic support system for 7 days, when standard foam tests were conducted according to the Roche foam test method specified in GB / T 13173-2008 at temperatures of 24℃ and 93.5℃, the foam volume measured at 24℃ was 40 mL, and the foam volume measured at 93.5℃ was 43 mL. The foam volume within 10 seconds after foaming stopped was not greater than 8 mL in either case.

[0075] This embodiment uses a low-viscosity, high-defoaming-performance formulation. The ethylene glycol content of 15wt% reduces the viscosity of the concentrate, facilitating transport and mixing. (C) 12 –C 14The fatty alcohol polyoxyethylene ether content of 8wt% and the ethylene oxide addition number of 6 reduce the tendency of foam formation. The solid content of intermediate X of 1.8wt% is at the upper limit of the preferred range, providing a stronger defoaming effect. The sodium borate content of 1.5wt% meets the basic corrosion inhibition requirements. The kinematic viscosity of the concentrate of 35mm² / s is suitable for rapid circulation systems. The combination of hydrophobic fumed silica with a specific surface area of ​​260m² / g and hydroxyl-terminated polydimethylsiloxane with a kinematic viscosity of 650mm² / s, along with a relatively high silica feed amount of 23 parts by mass, enables the average particle size of intermediate X to reach 110nm. The polydopamine shell content of 7wt% provides excellent dispersion stability and shear resistance. The high shear speed of 5200r / min ensures that intermediate X is uniformly dispersed in the low viscosity system. The working solution exhibits excellent rapid defoaming performance under both room temperature and high temperature conditions, and the increase in foam volume after 7 days of circulation is less than 10mL. This embodiment is applicable to high-cycle frequency mine hydraulic support systems, with an ambient temperature range of -5℃ to 35℃ and a working pressure of 25-35MPa. It is suitable for high-yield and high-efficiency fully mechanized mining faces with a coal seam dip angle of less than 15 degrees and a working face length of 100-200m, and is particularly suitable for applications with extremely high requirements for defoaming speed. It is especially suitable for thin coal seam mining using rapid advance technology.

[0076] Example 3

[0077] A fast-defoaming hydraulic support concentrate, by total mass, comprises 32 wt% ethylene glycol and 20 wt% C. 12 –C 14 The product consists of a fatty alcohol polyoxyethylene ether nonionic surfactant, 8 wt% sodium petroleum sulfonate rust inhibitor, 0.5 wt% core-shell organosilicon-silica-dopamine defoaming intermediate X (solid matter comprising 0.5 wt% of the total concentrated liquid mass), 4.5 wt% boric acid corrosion inhibitor, and the balance being water, totaling 100 wt%. This embodiment, C... 12 –C 14 The number of oxyethylene addition of the fatty alcohol polyoxyethylene ether nonionic surfactant is 9. In this embodiment, the effective active ingredient in the commercial sodium petroleum sulfonate rust inhibitor accounts for 4.8 wt% of the total mass of the concentrate.

[0078] The core-shell organosilicon-silica-dopamine defoaming intermediate X of this embodiment was prepared by the following steps: 140 parts by weight of hydroxyl-terminated polydimethylsiloxane, 10 parts by weight of hydrophobic fumed silica, 8 parts by weight of 3-aminopropyltriethoxysilane, 130 parts by weight of ethanol, 42 parts by weight of deionized water, 3 parts by weight of dopamine hydrochloride, and 3 parts by weight of tris(hydroxymethyl)aminomethane were weighed. Under an inert atmosphere protected by nitrogen, the hydroxyl-terminated polydimethylsiloxane was mixed with ethanol and deionized water and stirred at 85°C for 2.5 h. Under stirring, the hydrophobic fumed silica and 3-aminopropyltriethoxysilane were slowly added, and the reaction was continued at 100°C under reflux condensation for 5 h to obtain the organosilicon-silica composite slurry. The composite slurry was cooled to 32°C, and dopamine hydrochloride and tris(hydroxymethyl)aminomethane were added under air atmosphere. The pH of the system was adjusted to 8.3 with sodium hydroxide, and the mixture was stirred at 32°C for 6 hours to allow dopamine to undergo oxidative self-polymerization and deposit on the surface of the composite slurry particles under alkaline and dissolved oxygen conditions. Most of the ethanol and water in the resulting dispersion were removed under reduced pressure, and the mixture was vacuum dried at 70°C for 6 hours to obtain a core-shell organosilicon-silica-dopamine defoaming intermediate X solid with an average particle size of 175 nm. The average particle size was expressed as the volume median particle size measured by a dynamic light scattering particle size analyzer. The hydrophobic fumed silica used in this example had a specific surface area of ​​180 m² / g, and the kinematic viscosity of the hydroxyl-terminated polydimethylsiloxane at 25°C was 1350 mm² / s. In the core-shell organosilicon-silica-dopamine defoaming intermediate X particles prepared in this embodiment, the polydopamine shell layer accounts for 2.5 wt% of the total solid mass of intermediate X.

[0079] The concentrated solution preparation method in this embodiment includes the following steps: 32 kg of ethylene glycol, 35 kg of water, and 20 kg of C... 12 –C 14Fatty alcohol polyoxyethylene ether nonionic surfactant, 8 kg of commercial sodium petroleum sulfonate rust inhibitor, and 4.5 kg of boric acid corrosion inhibitor were added to a reactor equipped with stirring and heating functions. The mixture was stirred at 65℃ for 75 min to obtain a homogeneous matrix mixture, wherein the mass ratio of ethylene glycol to water was 1:1.1. The pH of the system was adjusted to 8.8 with sodium hydroxide. A core-shell organosilicon-silica-dopamine defoaming intermediate X was dispersed in water to prepare a dispersion with a solid content of 58 wt%. At 55℃, using a high-shear disperser at a shear speed of 3000 r / min, the dispersion was slowly added to the matrix mixture at a ratio of 0.5 wt% of the solid content of intermediate X to the total mass of the resulting concentrate. The shearing time was 15 min, yielding a semi-finished concentrate containing the dispersing defoaming intermediate X. The semi-finished concentrate was subjected to degassing under reduced pressure and then filtered to obtain a finished concentrate for rapid defoaming hydraulic supports. The concentrated solution prepared in this embodiment has a kinematic viscosity of 68 mm² / s at a temperature of 40°C. The kinematic viscosity was determined according to the national standard test method for kinematic viscosity of lubricating oil.

[0080] The concentrate of this embodiment was diluted with water to a mass fraction of 5 wt% to obtain the working solution. When standard foam tests were conducted according to the Roche foam test method specified in GB / T 13173-2008 at temperatures of 24℃ and 93.5℃, the foam volume obtained at 24℃ was 46 mL, and the foam volume decreased to 9 mL within 10 seconds after foaming stopped. At 93.5℃, the foam volume obtained was 49 mL, and the foam volume decreased to 10 mL within 10 seconds after foaming stopped. After circulating the working solution in a mine hydraulic support system for 7 days, when standard foam tests were conducted according to the Roche foam test method specified in GB / T 13173-2008 at temperatures of 24℃ and 93.5℃, the foam volume measured at 24℃ was 50 mL, and the foam volume measured at 93.5℃ was no greater than 50 mL. The foam volume within 10 seconds after foaming stopped was no greater than 12 mL in both cases.

[0081] This embodiment employs a high rust-preventive and high lubricity configuration; the ethylene glycol content of 32wt% provides excellent low-temperature fluidity and antifreeze properties. 12 –C 14The fatty alcohol polyoxyethylene ether content of 20wt% and the ethylene oxide addition number of 9 provide enhanced lubrication and cleaning performance. The sodium petroleum sulfonate content of 8wt% and the effective active ingredient of 4.8wt%, combined with the boric acid content of 4.5wt%, provide excellent rust prevention and corrosion inhibition protection. The solid content of intermediate X of 0.5wt% is within the preferred range, providing effective defoaming while maintaining system transparency. The kinematic viscosity of the concentrate of 68mm² / s is suitable for heavy-duty high-pressure hydraulic systems. The combination of hydrophobic fumed silica with a specific surface area of ​​180m² / g and hydroxyl-terminated polydimethylsiloxane with a kinematic viscosity of 1350mm² / s, along with a low silica feed amount of 10 parts by mass, enables intermediate X to achieve an average particle size of 175nm. The polydopamine shell content of 2.5wt% ensures dispersion stability while reducing the impact on lubrication performance. The low shear speed of 3000r / min avoids excessive shearing that affects the defoaming efficiency of intermediate X. The foaming volume of the working fluid is controlled within the specified range under normal and high temperature conditions, and the performance remains at an acceptable level after 7 days of repeated use. This embodiment is applicable to mine hydraulic support systems under high load and heavy operating conditions, with an ambient temperature range of -25℃ to 45℃ and a working pressure of 40-50MPa. It is suitable for fully mechanized longwall mining faces with a coal seam dip angle of 25-45 degrees and a working face length of 200-300m, and is applicable to application scenarios with high requirements for rust prevention and lubrication performance. It is especially suitable for mine environments with high sulfur content in coal seams or high mineralization of groundwater.

[0082] Example 4

[0083] A fast-defoaming hydraulic support concentrate comprises, by total mass, 12 wt% ethylene glycol, 6 wt% fatty alcohol polyoxyethylene ether nonionic surfactant, 2.0 wt% commercial sodium petroleum sulfonate rust inhibitor, 0.3 wt% core-shell organosilicon-silica-dopamine defoaming intermediate X (solid matter comprising 0.3 wt% of the total concentrate mass), 0.8 wt% sodium borate corrosion inhibitor, and the balance being water, totaling 100 wt%. In this embodiment, the fatty alcohol polyoxyethylene ether nonionic surfactant is C. 12 –C 14 The fatty alcohol polyoxyethylene ether has an oxyethylene addition number of 5. In this example, the effective active ingredient in the commercial sodium petroleum sulfonate rust inhibitor accounts for 1.2 wt% of the total mass of the concentrate.

[0084] The core-shell organosilicon-silica-dopamine defoaming intermediate X of this embodiment was prepared by the following steps: 105 parts by weight of hydroxyl-terminated polydimethylsiloxane, 7 parts by weight of hydrophobic fumed silica, 1.5 parts by weight of 3-aminopropyltriethoxysilane, 55 parts by weight of ethanol, 13 parts by weight of deionized water, 2 parts by weight of dopamine hydrochloride, and 2 parts by weight of tris(hydroxymethyl)aminomethane were weighed. Under an inert atmosphere protected by nitrogen, the hydroxyl-terminated polydimethylsiloxane was mixed with ethanol and deionized water and stirred at 63°C for 1.2 h. Under stirring, the hydrophobic fumed silica and 3-aminopropyltriethoxysilane were slowly added, and the reaction was continued at 83°C under reflux condensation for 2.5 h to obtain the organosilicon-silica composite slurry. The composite slurry was cooled to 22°C, and dopamine hydrochloride and tris(hydroxymethyl)aminomethane were added under air atmosphere. The pH of the system was adjusted to 8.2 with sodium hydroxide, and the mixture was stirred at 22°C for 11 hours to allow dopamine to undergo oxidative self-polymerization and deposit on the surface of the composite slurry particles under alkaline and dissolved oxygen conditions. Most of the ethanol and water in the resulting dispersion were removed under reduced pressure, and the mixture was vacuum dried at 45°C for 11 hours to obtain a core-shell organosilicon-silica-dopamine defoaming intermediate X solid with an average particle size of 90 nm. The average particle size was expressed as the volume median particle size measured by a dynamic light scattering particle size analyzer. The hydrophobic fumed silica used in this example had a specific surface area of ​​162 m² / g, and the kinematic viscosity of the hydroxyl-terminated polydimethylsiloxane at 25°C was 550 mm² / s. In the core-shell organosilicon-silica-dopamine defoaming intermediate X particles prepared in this embodiment, the polydopamine shell layer accounts for 1.5 wt% of the total solid mass of intermediate X.

[0085] The concentrated solution preparation method of this embodiment includes the following steps: 12 kg of ethylene glycol, 78.9 kg of water, 6 kg of fatty alcohol polyoxyethylene ether nonionic surfactant, 2.0 kg of commercial sodium petroleum sulfonate rust inhibitor, and 0.8 kg of sodium borate corrosion inhibitor are added to a reaction vessel equipped with stirring and heating functions. The mixture is stirred for 35 min at a temperature of 43°C to obtain a homogeneous matrix mixture. The mass ratio of ethylene glycol to water is 1:6.6. The pH value of the system is adjusted to 7.2 with hydrochloric acid. The core-shell organosilicon-silica-dopamine defoaming intermediate X is dispersed in water to prepare a dispersion with a solid content of 54 wt%. At a temperature of 33°C, the dispersion is slowly added to the matrix mixture using a high-shear disperser at a shear speed of 2400 r / min, with the solid content of intermediate X accounting for 0.3 wt% of the total mass of the obtained concentrated solution. The shearing time is 12 min to obtain a semi-finished concentrated solution containing the dispersed defoaming intermediate X. The concentrated semi-finished product was subjected to degassing under reduced pressure and then filtered to obtain the finished concentrated product for hydraulic supports with rapid defoaming. The kinematic viscosity of the concentrated product prepared in this embodiment was 25 mm² / s at a temperature of 40°C, and the kinematic viscosity was determined according to the national standard test method for kinematic viscosity of lubricating oil.

[0086] The concentrate of this embodiment was diluted with water to a mass fraction of 3 wt% to obtain the working solution. When standard foam tests were conducted according to the Roche foam test method specified in GB / T 13173-2008 at temperatures of 24℃ and 93.5℃, the foam volume obtained at 24℃ was 43 mL, and the foam volume decreased to 8 mL within 10 seconds after foaming stopped. At 93.5℃, the foam volume obtained was 47 mL, and the foam volume decreased to 9 mL within 10 seconds after foaming stopped. After circulating the working solution in a mine hydraulic support system for 7 days, when standard foam tests were conducted according to the Roche foam test method specified in GB / T 13173-2008 at temperatures of 24℃ and 93.5℃, the foam volume measured at 24℃ was 49 mL, and the foam volume measured at 93.5℃ was no greater than 50 mL. The foam volume within 10 seconds after foaming stopped was no greater than 11 mL in both cases.

[0087] This embodiment uses lower boundary parameter configurations. The ethylene glycol content of 12wt% is close to the lower limit of the specified range, with an 8% safety margin to provide basic antifreeze performance while maintaining extremely low concentrate viscosity. The surfactant content of 6wt% is near the lower limit of the range and uses the preferred lower limit value of 5 for the number of oxyethylene additions, meeting basic lubrication requirements while minimizing foam formation tendency. The commercial content of sodium petroleum sulfonate is 2.0wt%, and the effective active ingredient content is 1.2wt%, close to the preferred lower limit, providing necessary rust protection. The solid content of intermediate X is 0.3wt%, within the specified range and slightly above the lower limit, ensuring effective defoaming. The sodium borate content is 0.8wt%, close to the preferred lower limit, meeting basic corrosion inhibition requirements. The kinematic viscosity of the concentrate is 25mm² / s, close to the lower limit of the specified range, suitable for low-temperature environments and fast-flowing systems. The intermediate X is prepared using parameter configurations close to the lower limit, including hydroxyl-terminated polydimethylformamide. The preparation consists of 105 parts by weight of basic siloxane, 7 parts by weight of hydrophobic fumed silica with a specific surface area of ​​162 m² / g (close to the lower limit), 1.5 parts by weight of 3-aminopropyltriethoxysilane, hydroxyl-terminated polydimethylsiloxane with a kinematic viscosity of 550 mm² / s (close to the lower limit), 2 parts by weight each of dopamine hydrochloride and tris(hydroxymethyl)aminomethane, resulting in a polydopamine shell content of 1.5 wt% (close to the lower limit), and intermediate X with an average particle size of 90 nm (close to the lower limit), providing a large specific surface area to enhance defoaming efficiency. The preparation process uses temperature and time parameters close to the lower limit, including S1 temperature 43℃, stirring time 35 min, S2 temperature 33℃, shearing time 12 min, and shearing speed 2400 r / min. The solid content of intermediate X is 54 wt%, close to the lower limit, which facilitates uniform dispersion under low temperature conditions. The defoaming performance of the working solution meets the standard requirements under both room temperature and high temperature conditions, and the performance remains stable after 7 days of cyclic use. This embodiment is applicable to mine hydraulic support systems in low-temperature environments or where there are strict limitations on the viscosity of the concentrate. The ambient temperature range is 0℃ to 30℃, and the working pressure is 20-30MPa. It is suitable for small and medium-sized fully mechanized mining faces with a coal seam dip angle of less than 10 degrees and a working face length of 80-150m. It is suitable for application scenarios with high cost control requirements while meeting basic defoaming and rust prevention performance. It is particularly suitable for the initial trial operation stage of newly built mines or mines with seasonal mining.

[0088] Comparative Example 1: It is basically the same as Example 1, except that the mass fraction of ethylene glycol is 45 wt%, while the amounts of other components and preparation conditions remain unchanged.

[0089] Comparative Example 2: Basically the same as Example 1, except that the mass fraction of ethylene glycol is 8 wt%, while the amounts of other components and preparation conditions remain unchanged.

[0090] Comparative Example 3: It is basically the same as Example 1, except that the mass fraction of the fatty alcohol polyoxyethylene ether nonionic surfactant is 28 wt%, while the amounts of other components and preparation conditions remain unchanged.

[0091] Comparative Example 4: Basically the same as Example 1, except that the number of oxyethylene addition of the fatty alcohol polyoxyethylene ether nonionic surfactant is 15, and the amount of other components and preparation conditions remain unchanged.

[0092] Comparative Example 5: Basically the same as Example 1, except that the number of oxyethylene addition of the fatty alcohol polyoxyethylene ether nonionic surfactant is 2, and the amount of other components and preparation conditions remain unchanged.

[0093] Comparative Example 6: Basically the same as Example 1, except that the mass fraction of the commercial sodium petroleum sulfonate rust inhibitor is 12 wt%, while the amounts of other components and preparation conditions remain unchanged.

[0094] Comparative Example 7: It is basically the same as Example 1, except that the solid matter in the core-shell organosilicon-silica-dopamine defoaming intermediate X accounts for 6.5 wt% of the total mass of the concentrate, while the amount of other components and preparation conditions remain unchanged.

[0095] Comparative Example 8: It is basically the same as Example 1, except that the core-shell organosilicon-silica-dopamine defoaming intermediate X is not added, while the amount of other components and preparation conditions remain unchanged.

[0096] Comparative Example 9: It is basically the same as Example 1, except that the amount of hydrophobic fumed silica used in the preparation of core-shell organosilicon-silica-dopamine defoaming intermediate X is 35 parts by mass, while the amount of other raw materials and preparation conditions remain unchanged.

[0097] Comparative Example 10: It is basically the same as Example 1, except that dopamine hydrochloride and tris(hydroxymethyl)aminomethane are not added when preparing core-shell organosilicon-silica-dopamine defoaming intermediate X, the dopamine coating process in step A3 is omitted, and the organosilicon-silica composite slurry obtained in step A2 is directly concentrated and dried to obtain defoaming particles. The amount of other raw materials and preparation conditions remain unchanged.

[0098] Comparative Example 11: It is basically the same as Example 1, except that the reaction temperature of step A2 in preparing core-shell organosilicon-silica-dopamine defoaming intermediate X is 120°C, while the amount of other raw materials and preparation conditions remain unchanged.

[0099] Comparative Example 12: It is basically the same as Example 1, except that the pH value of step A3 is adjusted to 6.5 when preparing core-shell organosilicon-silica-dopamine defoaming intermediate X, while the amount of other raw materials and preparation conditions remain unchanged.

[0100] Comparative Example 13: Basically the same as Example 1, except that boric acid corrosion inhibitor was not added, while the amount of other components and preparation conditions remained unchanged.

[0101] Experiment 1: Kinematic Viscosity Test of Concentrated Liquid

[0102] The test subject was a concentrated liquid for rapid defoaming hydraulic supports. The purpose of the test was to evaluate the flow properties and transport performance of the concentrated liquid. The test principle was to measure the time required for the liquid to flow through a standard capillary tube at a specified temperature using a capillary viscometer, and then calculate the kinematic viscosity. The experimental method involved placing the concentrated liquid sample in a constant temperature bath at 40℃ for 30 minutes, and then using an Ubbelohde viscometer to determine the kinematic viscosity according to GB / T 265-1988 "Determination of Kinematic Viscosity and Calculation of Dynamic Viscosity of Petroleum Products". Each sample was measured in triplicate. The key parameters were: test temperature 40±0.1℃, and constant temperature time of not less than 30 minutes. Data processing involved taking the arithmetic mean of the three measurements as the result, with a relative deviation of no more than ±2%, and reporting in mm² / s.

[0103] Experiment 2: Working Fluid Foam Performance Test

[0104] The test subject is the working solution obtained by diluting the concentrate with water to a mass fraction of 3-5 wt%. The purpose of the test is to evaluate the foaming tendency and defoaming rate of the working solution under normal temperature and high temperature conditions. The test principle is to generate foam by bubbling with air at a specified temperature, and measure the foam volume and defoaming time. Standard foam tests are conducted at temperatures of 24℃ and 93.5℃, and the foam volume at the time of foaming cessation and the change in foam volume within 10 seconds after foaming cessation are recorded. Each sample is measured in triplicate. The standard is based on GB / T 13173-2008. The key parameters are the test temperature of 24±1℃ and 93.5±1℃, the bubbling time of 5 minutes, and the air flow rate of 200 mL / min. Data processing is to report the arithmetic mean ± standard deviation of the three measurements, in mL.

[0105] Experiment 3: Intermediate X Average Particle Size Test

[0106] The test subject was a core-shell organosilicon-silica-dopamine defoaming intermediate X solid. The purpose of the test was to characterize the particle size distribution of intermediate X. The test principle was to measure the Brownian motion velocity of particles in a liquid using dynamic light scattering technology, and calculate the particle size distribution using the Stokes-Einstein equation. The experimental method involved dispersing intermediate X solid in deionized water to prepare a dispersion with a mass concentration of 0.01 wt%, ultrasonicating for 10 minutes to ensure uniform dispersion, and using a dynamic light scattering particle size analyzer at 25℃ to determine the volume median particle size (D50) and particle size distribution. Each sample was measured in triplicate. Key parameters were: test temperature 25 ± 0.5℃, dispersion medium: deionized water, refractive index 1.45, and absorptivity 0.01. Data processing consisted of the arithmetic mean ± standard deviation of the three measured volume median particle size (D50), reported in nm.

[0107] Experiment 4: Specific Surface Area Test of Hydrophobic Vapor Phase Silica

[0108] The test subject was the hydrophobic fumed silica raw material used to prepare intermediate X. The purpose of the test was to characterize the specific surface area of ​​silica. The test principle was based on BET theory, calculating the specific surface area by measuring the multilayer adsorption of nitrogen on the material surface. The experimental method involved degassing the hydrophobic fumed silica sample under vacuum at 150℃ for 4 hours. A fully automated specific surface area and porosity analyzer was used to measure the nitrogen adsorption isotherm at liquid nitrogen temperature of 77K. The specific surface area was calculated according to the BET equation. Each sample was measured twice in parallel. Key parameters were: degassing temperature 150℃, degassing time no less than 4 hours, adsorbate nitrogen, and test temperature 77K. Data processing involved taking the arithmetic mean of the two measurements, reporting in m² / g, with a relative deviation of no more than ±5%.

[0109] Experiment 5: Kinematic viscosity test of hydroxyl-terminated polydimethylsiloxane

[0110] The test subject was hydroxyl-terminated polydimethylsiloxane raw material used in the preparation of intermediate X. The purpose of the test was to characterize the molecular weight and flow properties of the silicone oil. The test principle was to measure the time required for the liquid to flow through a standard capillary at a specified temperature using a capillary viscometer and calculate the kinematic viscosity. The experimental method involved placing the hydroxyl-terminated polydimethylsiloxane sample in a constant temperature bath at 25℃ for 30 minutes, with each sample measured in triplicate. The standard was based on GB / T 265-1988. The key parameters were a test temperature of 25±0.1℃ and a holding time of at least 30 minutes. Data processing involved taking the arithmetic mean of the three measurements as the result, with a relative deviation of no more than ±2%, and reporting in mm² / s.

[0111] Experiment 6: Polydopamine shell content test

[0112] The test subject was solid core-shell organosilicon-silica-dopamine defoaming intermediate X. The purpose of the test was to quantitatively characterize the mass percentage of the polydopamine shell in intermediate X. The test principle was to determine the thermogravimetric analysis (TGA) curve of the sample under a nitrogen atmosphere, and calculate the polydopamine content by subtraction based on the thermal decomposition behavior of organosilicon, silica, and polydopamine in different temperature ranges. The experimental method involved weighing 5-10 mg of solid intermediate X into a platinum crucible, heating it from 30°C to 800°C at a rate of 10°C / min under a nitrogen atmosphere using a TGA instrument, and recording the thermogravimetric analysis curve. The polydopamine content was calculated based on the residual mass in the 600-800°C range and the weight loss in the 200-400°C range. Each sample was measured twice in parallel. Key parameters were a nitrogen flow rate of 50 mL / min and a heating rate of 10°C / min. Data processing involved calculating the polydopamine mass fraction based on the TG curve and reporting it as wt%.

[0113] Experiment 7: Foam Performance Test After Working Fluid Recycling

[0114] The test subject was the working fluid in a mine hydraulic support system after 7 days of circulation. The purpose of the test was to evaluate the stability of the defoaming performance of the working fluid under long-term circulation conditions. The test principle was to generate foam by air bubbling at a specified temperature, measure the foam volume and defoaming time, and compare it with fresh working fluid. The experimental method was to conduct standard foam tests on the working fluid samples after 7 days of circulation according to the Roche foam test method specified in GB / T 13173-2008, at temperatures of 24℃ and 93.5℃. The foam volume at the time of foaming cessation and the foam volume within 10 seconds after foaming cessation were recorded. Each sample was measured in triplicate, and the results were compared with those of fresh working fluid. The key parameters were: test temperature 24±1℃ and 93.5±1℃, bubbling time 5 minutes, air flow rate 200mL / min, and circulation time 7 days. Data processing involved taking the arithmetic mean ± standard deviation of the three measurements to calculate the increase in foam volume relative to fresh working fluid.

[0115] Figure 1 The DLS particle size distribution curves for Examples 1 to 4 and Comparative Example 10 are shown. The parameters were kept constant: the solid-liquid content of intermediate X dispersion, ionic strength, and measurement temperature of 25°C. The particle size distribution was characterized by volume fraction using dynamic light scattering. The varying parameters were whether a polydopamine shell was constructed and the average particle size D50 resulting from its content control: 90 nm, 110 nm, 140 nm, 175 nm, and 400 nm for Comparative Example 10 (without a shell). The results show that the particle size distribution of Examples 1 to 4 exhibits a narrow single peak, with D50 concentrated between 90 and 175 nm and a PDI below 0.25. In contrast, the particle size distribution of Comparative Example 10 is significantly broadened and shifts towards larger particle sizes, with D50 increasing to 400 nm and a longer tail. This indicates that the polydopamine shell can effectively suppress inorganic core aggregation, resulting in a stable and narrowly distributed nanoscale intermediate X particle size structure.

[0116] Figure 2 The bar charts show the PDI (polydispersity index) of Examples 1 to 4 and Comparative Example 10. The parameters were kept constant: testing instrument, scattering angle, and SiO2 core content in the sample formulation. The PDI was measured using dynamic light scattering (DLS) as an indicator of particle size uniformity. The varying parameters were the presence or absence of the polydopamine shell and its areal density. The PDI of Examples 1 to 4 is concentrated in the range of 0.15 to 0.22, all within the narrow distribution range typically determined by DLS. However, the PDI of Comparative Example 10, without the polydopamine shell, increased to 0.65, exhibiting a significantly wider distribution. These results indicate that introducing a polydopamine organic shell under the same inorganic core conditions can significantly reduce the particle size distribution width, improve the structural consistency and long-term stability of the dispersion, and provide a foundation for obtaining low-foaming and stable working fluids under high shear and high solids content conditions.

[0117] Figure 3 The TGA TG curves for Examples 1 to 4 and Comparative Example 10 are shown. The parameters were kept constant: heating program from 30 to 800°C, heating rate from 10°C / min, nitrogen protective atmosphere, and consistent sample pre-drying conditions. Thermogravimetric analysis (TGA) was used to record the mass change with temperature. The changing parameters were the ratio differences between different samples of the polydopamine shell content (1 to 10 wt%) and silica content (5 to 30 wt%) in intermediate X. The curves show that from 30 to 200°C, the main weight loss is due to slight physical adsorption of water and residual solvent. From 200 to 400°C, the weight loss is positively correlated with the polydopamine content; the higher the polydopamine content, the more significant the mass loss in this range. From 600 to 800°C, the residual mass matches well with the silica content, and the thermally stable residue remains stable at the corresponding inorganic ratio. These results demonstrate that the organic shell and inorganic core content of intermediate X can be quantitatively distinguished using thermogravimetric analysis, proving the reasonable structural design and controllable ratio of the intermediate.

[0118] Figure 4 The TGA DTG curves for Examples 1 to 4 and Comparative Example 10 are shown. The parameters were kept identical to those used in the TG test, including a heating range of 30 to 800°C, a heating rate of 10°C·min⁻¹, and a nitrogen atmosphere. The mass change rate as a function of temperature was obtained by numerically differentiating the TG curves. The varying parameters were the influence of the presence and content of the polydopamine shell on the position and area of ​​the thermal decomposition peak. The Example samples showed a significant weight loss peak corresponding to polydopamine in the 200 to 400°C range, and a main peak related to the thermal decomposition of the siloxane backbone in the 400 to 600°C range. Comparative Example 10 showed almost no DTG peaks in the 200 to 400°C range, exhibiting only a single siloxane decomposition peak in the 400 to 600°C range. This difference indicates that the polydopamine shell truly exists in intermediate X and its thermal decomposition behavior is consistent with similar structures in the literature, without significantly weakening the thermal stability of the matrix siloxane skeleton.

[0119] Figure 5The figures show the volume-time curves of Roche foam as a function of time for Example 1 and Comparative Example 8 at 24°C and 93.5°C. The parameters were fixed: liquid height, drop height, flow rate, and graduated cylinder specifications were uniform. The test method was the Roche foam method as described in GB / T 13173-2008. The variable parameters were whether intermediate X was introduced and the temperature increase from 24°C to 93.5°C. The curves use the volume at the moment of foaming and the volume 10 seconds after foaming stops as boundary points, describing the change in foam volume from 0 to 10 seconds through exponential decay. Example 1 initially had a foam volume of only about 40 mL at 24°C and 93.5°C, rapidly decreasing to below 10 mL after 10 seconds. In contrast, Comparative Example 8, without intermediate X, had an initial volume exceeding 120 mL and maintained above 80 mL after 10 seconds. The results show that under the same experimental conditions, the introduction of intermediate X significantly accelerates the foam decay rate and reduces the foam stabilization ability, while exhibiting stable and rapid defoaming characteristics under both room temperature and near-boiling point conditions.

[0120] Figure 6 The bar charts show the foaming volumes of Examples 1 to 4 and Comparative Example 8 at 24°C and 93.5°C. Fixed parameters included the experimental setup, flow rate, head difference, and working fluid concentration. The characterization method was the direct reading of the instantaneous foaming volume during the Roche foam test. Varying parameters included whether the sample formulation contained intermediate X and other defoaming synergistic components. The results show that the foaming volumes of Examples 1 to 4 at 24°C and 93.5°C were all controlled within the range of 30 to 50 mL. The increase in foaming volume with increasing temperature was limited. However, Comparative Example 8, which did not contain intermediate X, exhibited foaming volumes exceeding 120 mL and 130 mL at both temperatures, significantly higher than the Example series. This bar chart comparison demonstrates that intermediate X can effectively suppress the initial foaming process and reduce instantaneous foam volume formation at both high and room temperatures, providing a basis for maintaining a stable low-foaming state in hydraulic support systems over a wide temperature range.

[0121] Figure 7The bar chart shows the 10-second foam volume of Examples 1 to 4 and Comparative Example 8 at 24°C and 93.5°C. The parameters were the same as those used in the foam volume test, including the experimental setup and working solution ratio. The residual foam volume in the graduated cylinder 10 seconds after foaming stopped was recorded using the Roche foam method. The varying parameters were the different sample formulations and the test temperature. In the figure, the 10-second foam volume of Examples 1 to 4 at 24°C and 93.5°C did not exceed 10 mL, indicating rapid defoaming. In contrast, the residual foam volume of Comparative Example 8 at the same time point still exceeded 80 mL, and this was more severe at higher temperatures. These results further demonstrate from a foam stabilization perspective that intermediate X and its surface regulation combination can significantly reduce foam persistence, balancing low foaming and rapid defoaming, enabling the system to maintain good defoaming control under complex conditions such as high-flow-rate impact and high-temperature reflux.

[0122] Figure 8 The table shows the Zeta potential histograms for Examples 1 to 4 and Comparative Example 10 at approximately pH 8 and 25°C. The parameters were fixed: electrophoretic light scattering instrument, sample solid content, and ionic strength were the same. Zeta potential was used to characterize the interfacial charge and electrostatic stability of the dispersion system. The varying parameters were the presence or absence of a polydopamine organic shell and the effect of its content on the surface charge. The results show that the Zeta potentials of Examples 1 to 4 are concentrated in the range of −35 to −45 mV, with absolute values ​​all greater than 30 mV, consistent with the empirical criterion for relatively stable dispersion systems. In contrast, the Zeta potential of Comparative Example 10, without polydopamine coating, is only about −12 mV, placing it in a low-stability range prone to flocculation and aggregation. Therefore, the polydopamine shell significantly increases the negative surface potential of intermediate X, enhances electrostatic repulsion, and helps maintain the uniform distribution of nanoparticles under high shear conditions and long-term cycling.

[0123] Figure 9 The Zeta-pH curves for Example 1 and Comparative Example 10 show the Zeta potential as a function of pH within the pH range of 6.5 to 9.0. The parameters were kept constant: measurement temperature 25°C, sample solid content, ionic strength, and electrophoretic light scattering test conditions. The parameters that varied were the system pH being gradually adjusted from near neutral to weakly alkaline and whether the sample possessed a polydopamine shell. The curves show that the absolute value of the Zeta potential in Example 1 gradually increased with increasing pH, steadily rising from approximately -25 mV to approximately -45 mV, remaining within a relatively stable range. In contrast, the Zeta potential in Comparative Example 10 only changed slowly between -5 and -15 mV across the entire pH range, failing to form effective electrostatic repulsion. These results indicate that the polydopamine-modified intermediate X can maintain high surface charge and stability within the common operating pH range, exhibiting better resistance to shearing, centrifugation, and salt disturbance, providing a reliable guarantee for the system to maintain low foaming and stable dispersion in practical applications over a long period.

[0124] As can be seen from the performance of the examples and comparative examples in Table 1, the kinematic viscosity of the concentrates in Examples 1-4 was controlled within the preferred range of 20-80 mm² / s. The foaming volume at 24℃ and 93.5℃ was no greater than 50 mL, and the foam volume within 10 seconds after foaming stopped was no greater than 10 mL. The foam performance remained stable after 7 days of cyclic use. Comparative Example 1 showed a significant increase in concentrate viscosity to 95 mm² / s and a deterioration in foam performance due to excessively high ethylene glycol content. Comparative Example 2 showed insufficient antifreeze performance and increased foam stability due to excessively low ethylene glycol content. Comparative Examples 3 and 4 showed a significantly enhanced foaming tendency and a significantly reduced defoaming rate due to excessively high surfactant content or excessively high ethylene oxide addition number. Comparative Example 5 showed decreased lubrication performance and increased foam stability due to excessively low ethylene oxide addition number. Comparative Example 6 showed increased concentrate viscosity and deteriorated foam performance due to excessively high sodium petroleum sulfonate content. Comparative Example 7 showed excessively high concentrate viscosity due to excessively high intermediate X content. Comparative Example 8 showed a different result due to the absence of [specific additive]. Intermediate X resulted in a foam volume as high as 125-155 mL, and the foam volume reached 85-92 mL within 10 seconds, proving that intermediate X is crucial for rapid defoaming. Comparative Example 9 had excessively high viscosity of the concentrate due to excessive silica dosage. Comparative Example 10 had a significant decrease in defoaming performance due to the omission of the dopamine coating step. Comparative Example 11 had a defoaming effect due to structural changes in intermediate X caused by excessively high reaction temperature. Comparative Example 12 had a significant decrease in defoaming performance due to the inability of dopamine to effectively polymerize due to excessively low pH value, which affected shell formation. Comparative Example 13 had a significant increase in foam volume and decreased rust prevention performance after repeated use due to the absence of boric acid corrosion inhibitor.

[0125] Table 1 Performance comparison data of the examples and comparative examples

[0126] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that any equivalent structural transformations made under the concept of the present invention and using the contents of the specification and drawings of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A concentrated fluid for a rapid defoaming hydraulic support, characterized in that, Including by total mass: 10–40 wt% ethylene glycol; 5–25 wt% of a fatty alcohol polyoxyethylene ether nonionic surfactant, wherein the number of oxyethylene addition of the fatty alcohol polyoxyethylene ether nonionic surfactant is 5–10. 1–10 wt% sodium petroleum sulfonate rust inhibitor; The solid matter of the core-shell organosilicon-silica-dopamine defoaming intermediate X accounts for 0.2–2 wt% of the total mass of the concentrate. The 0.2–2 wt% is based on the mass of the solid matter in the core-shell organosilicon-silica-dopamine defoaming intermediate X. The core-shell organosilicon-silica-dopamine defoaming intermediate X is an organosilicon-silica core particle obtained by condensation and composite of hydroxyl-terminated polydimethylsiloxane, hydrophobic fumed silica and 3-aminopropyltriethoxysilane. The core-shell composite particles are formed by the oxidation and self-polymerization of dopamine hydrochloride on the surface of the core particles under alkaline conditions regulated by tris(hydroxymethyl)aminomethane to form a polydopamine shell. 0.5–10 wt% boric acid or borate corrosion inhibitor; And the remainder is water.

2. The concentrate according to claim 1, characterized in that, The core-shell organosilicon-silica-dopamine defoaming intermediate X was prepared through the following steps: A1. Raw material preparation: Weigh the raw materials according to the following proportions: 100-150 parts by weight of hydroxyl-terminated polydimethylsiloxane, 5-30 parts by weight of hydrophobic fumed silica, 1-10 parts by weight of 3-aminopropyltriethoxysilane, 50-150 parts by weight of ethanol, 10-50 parts by weight of deionized water, 1-10 parts by weight of dopamine hydrochloride, and 1-10 parts by weight of tris(hydroxymethyl)aminomethane. A2. Organosilicon-silica composite: Under an inert atmosphere, hydroxyl-terminated polydimethylsiloxane is mixed with ethanol and deionized water, and stirred at 60–90°C for 1–3 h. Hydrophobic fumed silica and 3-aminopropyltriethoxysilane are slowly added while stirring, and the reaction is continued at 80–100°C under reflux and condensation conditions for 2–6 h to obtain organosilicon-silica composite slurry. A3. Dopamine Coating: The composite slurry obtained in step A2 is cooled to a temperature of 20–35°C. The dopamine hydrochloride and the tris(hydroxymethyl)aminomethane are added in an air atmosphere. The pH of the system is adjusted to 8.0–9.5 with sodium hydroxide or hydrochloric acid. The mixture is stirred at a temperature of 20–35°C for 4–12 hours to allow dopamine to undergo oxidative self-polymerization and deposit on the surface of the composite slurry particles under alkaline and dissolved oxygen conditions. A4. Concentration and Drying: The dispersion obtained in step A3 is subjected to reduced pressure to remove most of the ethanol and water, and then vacuum dried at a temperature of 40–80°C for 4–12 h to obtain a core-shell organosilicon-silica-dopamine defoaming intermediate X solid with an average particle size of 80–200 nm. The average particle size is preferably expressed as the median particle size measured by a dynamic light scattering particle size analyzer.

3. The concentrate according to claim 2, characterized in that, In step A1, the specific surface area of ​​the hydrophobic fumed silica is 150–300 m² / g, and the kinematic viscosity of the hydroxyl-terminated polydimethylsiloxane at a temperature of 25°C is 500–1500 mm² / s.

4. The concentrate according to claim 2, characterized in that, In the core-shell organosilicon-silica-dopamine defoaming intermediate X particles obtained after step A3, the polydopamine shell layer accounts for 1–10 wt% of the total solid mass of intermediate X.

5. The concentrate according to any one of claims 1, characterized in that, The solid content of the core-shell organosilicon-silica-dopamine defoaming intermediate X in the concentrate is 0.2–2.0 wt%, and the kinematic viscosity of the concentrate at a temperature of 40°C is 20–80 mm² / s, which is determined according to the national standard method for testing the kinematic viscosity of lubricating oil.

6. The concentrate according to any one of claims 1, characterized in that: The fatty alcohol polyoxyethylene ether nonionic surfactant is C. 12 –C 14 Fatty alcohol polyoxyethylene ether, wherein the number of oxyethylene addition of the nonionic surfactant in the fatty alcohol polyoxyethylene ether is 5–10; The effective active ingredient in the sodium petroleum sulfonate rust inhibitor comprises 1–6 wt% of the total mass of the concentrate. The boric acid or borate corrosion inhibitor has a mass fraction of 0.5–5 wt%.

7. The concentrate according to any one of claims 1, characterized in that, When the working solution obtained by diluting the concentrate with water to 3–5 wt% is subjected to a standard foam test according to the Roche foam test method specified in GB / T 13173-2008 at temperatures of 24℃ and 93.5℃, the foam volume obtained at each temperature condition shall not exceed 50 mL, and the foam volume shall drop to not exceed 10 mL within 10 seconds after foaming stops.

8. A method for preparing a concentrated fluid for a rapid defoaming hydraulic support according to any one of claims 1-7, characterized in that, The method includes the following steps: S1. Matrix premixing: Ethylene glycol, water, the fatty alcohol polyoxyethylene ether nonionic surfactant, the sodium petroleum sulfonate rust inhibitor, and boric acid or borate corrosion inhibitor added according to the mass fraction range of claim 1 when selected, are added to a reaction vessel equipped with stirring and heating functions. The mixture is stirred for 30–90 min at a temperature of 40–70°C to obtain a homogeneous matrix mixture, wherein the mass ratio of ethylene glycol to water is 1:0.5–1:7.0, and the pH value of the system is adjusted to 7.0–9.0 with sodium hydroxide or hydrochloric acid. S2. Adding defoaming intermediate X: Under conditions of temperature of 30–60°C and under stirring or shearing conditions, the core-shell organosilicon-silica-dopamine defoaming intermediate X, which exists in the form of a dispersion with a solid content of 50–80 wt%, is slowly added to the matrix mixture at a ratio of 0.1–5 wt% of the solid matter in the core-shell organosilicon-silica-dopamine defoaming intermediate X to the total mass of the obtained concentrate. The shearing time is 10–30 min, to obtain a concentrate semi-finished product containing the dispersion defoaming intermediate X. S3. Degassing and Filtration: The concentrated semi-finished product obtained in step S2 is subjected to degassing under reduced pressure, and then filtered to obtain the concentrated product for the rapid defoaming hydraulic support.

9. The preparation method according to claim 8, characterized in that: The shearing equipment used in step S2 is a high-shear disperser; When the preparation method is carried out continuously for three or more batches, the kinematic viscosity of the concentrate obtained in each batch at a temperature of 40°C deviates from the arithmetic mean of the kinematic viscosity of each batch by no more than ±10%.

10. The preparation method according to claim 8, characterized in that, When the concentrated solution prepared by the method is mixed with water at a mass fraction of 3–5 wt% to obtain a working fluid, and the fluid is circulated in the mine hydraulic support system for 7 days, the foam volume measured under the standard foam test method specified in GB / T 13173-2008 at temperatures of 24℃ and 93.5℃ shall not exceed 50 mL at each temperature, and the foam volume within 10 seconds after foaming stops shall not exceed 15 mL.

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