Method and device for recycling silicone oil by recycling alkaline residues

Abstract

The invention provides a method and device for recycling silicone oil by recycling alkaline residues, and the method comprises the following steps: stirring and dissolving the alkaline residues to obtain a dissolved material; carrying out three-phase separation treatment on the dissolved material to obtain alkali liquor at the lower layer, an oil phase at the upper layer and an emulsion at the middle layer; wherein the alkali liquor is used for alkali washing and recycling, and the oil phase is used for recycling silicone oil; adding composite salt water into the emulsion, and carrying out centrifugal demulsification treatment to obtain recovered silicone oil and wastewater; enabling the recovered silicone oil to participate in three-phase separation treatment again; wherein the composite salt water comprises sodium salt, potassium salt and magnesium salt; the silicon oil can be efficiently recycled, meanwhile, the separated alkali liquor can be directly reused in the production process, the problems of silicon oil waste and environmental pollution in traditional alkali residue treatment are solved, the whole technological process is simple and efficient, conventional equipment is adopted, complex additives are not needed, and energy consumption is low; and an innovative and practical solution is provided for alkaline residue resourceful treatment in the organic silicon industry.

Description

Technical Field

[0001] The invention belongs to the technical field of organic silicon, and particularly relates to a method and device for recycling silicone oil by recycling alkali residue. Background Art

[0002] During the organosilicon production process, the alkali residue produced after the silicone oil is neutralized with solid alkali contains 3% to 10% unrecovered silicone oil and residual alkali liquor. Currently, this alkali residue is typically directly treated for pollution-free disposal, resulting in the waste of high-value components and posing environmental risks. Because the silicone oil and alkali liquor in the alkali residue form a stable emulsion and are contaminated with solid impurities, traditional separation technologies are difficult to efficiently recover the silicone oil and alkali liquor.

[0003] Therefore, there is an urgent need to develop a separation and recycling process for organosilicon alkali slag to achieve resource utilization, improve economic benefits and meet environmental protection requirements. Summary of the Invention

[0004] The present invention provides a method and device for recycling silicone oil by recycling alkali residue, which are used to solve the problem that the effective components in the alkali residue cannot be efficiently recycled in the prior art.

[0005] In a first aspect, the present invention provides a method for recycling silicone oil by recycling alkali residue, comprising the following steps:

[0006] Stirring and dissolving the alkali residue to obtain dissolved material;

[0007] The dissolved material is subjected to a three-phase separation process to obtain an alkali solution in the lower layer, an oil phase in the upper layer, and an emulsion in the middle layer; wherein the alkali solution is used for alkali washing and recycling, and the oil phase is used for silicone oil recycling;

[0008] Compound salt water is added to the emulsion for centrifugal demulsification treatment to obtain recovered silicone oil and wastewater; the recovered silicone oil is re-involved in the three-phase separation treatment; wherein the compound salt water includes sodium salt, potassium salt and magnesium salt.

[0009] Compared with the existing technology, the benefits of the present invention are: through the synergistic process of stirring dissolution, three-phase separation and composite brine demulsification, efficient recovery and recycling of silicone oil and alkali liquor in alkali slag are achieved, wherein the synergistic effect of sodium salt, potassium salt and magnesium salt in the composite brine significantly improves the demulsification efficiency, so that the silicone oil is efficiently recovered. At the same time, the separated alkali liquor can be directly reused in the production process, which not only solves the problems of silicone oil waste and environmental pollution in traditional alkali slag treatment, but also the entire process is simple, efficient and low-cost, uses conventional equipment, does not require complex additives, and has low energy consumption, providing an innovative and practical solution for the resource treatment of alkali slag in the silicone industry.

[0010] Furthermore, the stirring and dissolving treatment time is 1 to 3 hours, the stirring speed is 30 to 50 rpm, and the temperature is 55 to 75°C.

[0011] Furthermore, the configuration temperature of the composite brine is 40-85°C.

[0012] Furthermore, during the preparation of the composite brine, nitrogen is introduced for bubbling treatment, and the nitrogen introduction rate is 5 to 30 m 3 / h.

[0013] Furthermore, the mass ratio of sodium salt, potassium salt and magnesium salt is 1:(0.2-0.7):(10-20).

[0014] Furthermore, in the centrifugal demulsification treatment, the mass ratio of the emulsion to the composite brine is 10:(1-3).

[0015] Furthermore, the sodium salt includes at least one of sodium chloride, sodium carbonate, sodium fatty alcohol alkyl sulfonate, sodium sulfate and sodium nitrate; and / or, the potassium salt includes at least one of potassium chloride, potassium carbonate, potassium sulfate or potassium nitrate; and / or, the magnesium salt includes at least one of magnesium chloride, magnesium nitrate or magnesium sulfate.

[0016] Furthermore, the rotation speed of the centrifugal demulsification treatment is 3000-5000 r / min, and the time is 4-7 hours.

[0017] In a second aspect, the present invention provides a device for recycling alkali residue and recovering silicone oil, which is used to perform the method for recycling alkali residue and recovering silicone oil described in the first aspect, and comprises a dissolving kettle, a three-phase separator, an emulsion buffer tank, a centrifugal demulsifier and a brine preparation tank; wherein, the alkali residue is introduced into the material inlet of the dissolving kettle, the outlet of the dissolving kettle is connected to the material inlet of the three-phase separator, the alkali liquid outlet at the bottom of the three-phase separator is used to output the alkali liquid, the oil phase outlet at the top of the three-phase separator is used to output the oil phase, the emulsion outlet in the middle of the three-phase separator is connected to the inlet of the emulsion buffer tank, the outlet of the emulsion buffer tank is connected to the material inlet of the centrifugal demulsifier, the outlet of the brine preparation tank is connected to the brine inlet of the centrifugal demulsifier, the silicone oil outlet of the centrifugal demulsifier is connected to the reflux port of the three-phase separator, and the wastewater outlet of the centrifugal demulsifier is used for drainage.

[0018] Furthermore, it also includes a hot water tank and a brine metering tank; the outlet of the hot water tank is connected to the inlet of the dissolution kettle and the inlet of the brine preparation tank respectively, and the outlet of the brine preparation tank is connected to the brine inlet of the centrifugal demulsifier through the brine metering tank. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 Schematic diagram of an apparatus for recycling alkali residue and recovering silicone oil in one embodiment of the present invention;

[0020] Figure 2 Schematic diagram of a dissolving kettle in one embodiment of the present invention.

[0021] Description of reference numerals:

[0022] 1. Dissolving kettle; 2. Three-phase separator; 3. Emulsion buffer tank; 4. Centrifugal demulsifier; 5. Brine preparation tank; 6. Hot water tank; 7. Silicone oil recovery tank; 8. Oil recovery pump; 9. Brine metering tank; 101. Removable filter plate. DETAILED DESCRIPTION

[0023] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0024] In a first aspect, the present invention provides a method for recycling silicone oil by recycling alkali residue, comprising the following steps:

[0025] Stirring and dissolving the alkali residue to obtain dissolved material;

[0026] The dissolved material is subjected to a three-phase separation process to obtain an alkali solution in the lower layer, an oil phase in the upper layer, and an emulsion in the middle layer; wherein the alkali solution is used for alkali washing and recycling, and the oil phase is used for silicone oil recycling;

[0027] Compound salt water is added to the emulsion for centrifugal demulsification treatment to obtain recovered silicone oil and wastewater; the recovered silicone oil is re-involved in the three-phase separation treatment; wherein the compound salt water includes sodium salt, potassium salt and magnesium salt.

[0028] The alkali residue of the present invention is derived from the waste residue generated after the silicone oil is neutralized with a solid alkali (such as sodium hydroxide, sodium carbonate, etc.) during the production of organosilicon. Specifically, it is a by-product formed when an alkaline substance is used to neutralize, wash, or adjust the pH of the acidic components during the synthesis of organosilicon monomers, silicone oil refining, or post-treatment processes. The alkali residue typically contains 85-95% sodium carbonate, 3-10% incompletely separated silicone oil, and 2-5% emulsion; wherein the silicone oil is a hydrolysis product of a high-boiling substance with a boiling point of 110-130°C, and its main component is a polymethylsiloxane mixture, the structure of which is mainly composed of silicon-oxygen bonds, silicon-carbon bonds, and silicon-silicon bonds, and has some side chains; the main component of the emulsion is siloxane.

[0029] Because the stable oil-water-solid emulsion system of alkali residue requires direct disposal, it wastes resources and puts pressure on the environment. The recovery process of the present invention allows for the effective separation and recycling of the silicone oil and alkali liquor in the alkali residue. Since the alkali residue dissolves into alkali liquor, silicone oil, and emulsion, the silicone oil is fully recovered in separate layers. A small amount of silicone oil in the alkali liquor is also recycled into the silicone oil system during alkali washing, resulting in efficient recovery of the entire silicone oil.

[0030] The method for recycling silicone oil by recycling alkali residue provided by the present invention realizes the efficient recovery and recycling of silicone oil and alkali liquor in alkali residue through the coordinated process of stirring and dissolving, three-phase separation and composite brine demulsification. The sodium salt, potassium salt and magnesium salt in the composite brine synergistically improve the demulsification efficiency, so that the silicone oil is efficiently recovered. At the same time, the separated alkali liquor can be directly reused in the production process. This not only solves the problems of silicone oil waste and environmental pollution in traditional alkali residue treatment, but also the entire process is simple, efficient and low-cost. Conventional equipment is used, no complex additives are required, and energy consumption is low. This provides an innovative and practical solution for the resource treatment of alkali residue in the silicone industry.

[0031] Furthermore, the stirring and dissolving treatment time is 1 to 3 hours, the stirring speed is 30 to 50 rpm, and the temperature is 55 to 75° C. This process parameter range can ensure that the alkali residue is fully dissolved and forms a uniform material system, further reducing energy consumption and waste.

[0032] Furthermore, the preparation temperature of the composite brine is 40-85° C. This temperature range is conducive to the full dissolution of each salt and the formation of a stable composite brine system, further improving the demulsification effect.

[0033] In a specific embodiment, during the preparation of the composite brine, nitrogen is introduced for bubbling treatment, and the nitrogen introduction rate is 5 to 30 m 3 / h. Nitrogen bubbling can further promote the uniform dissolution of salts and further improve the demulsification effect.

[0034] Specifically, the mass ratio of sodium salt, potassium salt, and magnesium salt is 1:(0.2-0.7):(10-20). During the centrifugal demulsification process, the mass ratio of the emulsion to the composite brine is 10:(1-3). The sodium salt includes at least one of sodium chloride, sodium carbonate, sodium fatty alcohol alkyl sulfonate, sodium sulfate, and sodium nitrate; the potassium salt includes at least one of potassium chloride, potassium carbonate, potassium sulfate, or potassium nitrate; and the magnesium salt includes at least one of magnesium chloride, magnesium nitrate, or magnesium sulfate.

[0035] The composite brine defined by the above parameters can produce a better synergistic demulsification effect, provide an optimal ion environment, and significantly improve the recovery rate of silicone oil.

[0036] Optionally, the rotation speed of the centrifugal demulsification treatment is 3000-5000 r / min, and the time is 4-7 hours.

[0037] Second, see Figure 1The present invention provides a device for recycling alkali residue and recovering silicone oil, which is used to perform the method for recycling alkali residue and recovering silicone oil described in the first aspect, and comprises a dissolving kettle 1, a three-phase separator 2, an emulsion buffer tank 3, a centrifugal demulsifier 4 and a brine preparation tank 5; wherein, the alkali residue is introduced into the material inlet of the dissolving kettle 1, the outlet of the dissolving kettle 1 is connected with the material inlet of the three-phase separator 2, the alkali liquid outlet at the bottom of the three-phase separator 2 is used to output the alkali liquid, the oil phase outlet at the top of the three-phase separator 2 is used to output the oil phase, the emulsion outlet in the middle of the three-phase separator 2 is connected with the inlet of the emulsion buffer tank 3, the outlet of the emulsion buffer tank 3 is connected with the material inlet of the centrifugal demulsifier 4, the outlet of the brine preparation tank 5 is connected with the brine inlet of the centrifugal demulsifier 4, the silicone oil outlet of the centrifugal demulsifier 4 is connected with the reflux port of the three-phase separator 2, and the wastewater outlet of the centrifugal demulsifier 4 is used for drainage.

[0038] Specifically, the alkali residue enters the dissolution kettle 1 through the material inlet of the dissolution kettle 1 for stirring and dissolving treatment, and the dissolved material leaves through the outlet of the dissolution kettle 1, and then enters the three-phase separator 2 through the material inlet of the three-phase separator 2 for three-phase separation treatment. Alkali solution is obtained in the lower layer of the three-phase separator 2 for alkali washing and recycling, and the oil phase is obtained in the upper layer of the three-phase separator 2 for silicone oil product recycling. The middle layer obtains an emulsion, and the emulsion leaves through the emulsion outlet in the middle of the three-phase separator 2 and is passed into the emulsion buffer tank 3. Thereafter, it is quantitatively passed into the centrifugal demulsifier 4 and subjected to centrifugal demulsification treatment with the brine from the brine preparation tank 5. The recovered silicone oil obtained after demulsification is re-introduced into the three-phase separator 2 through the reflux port of the three-phase separator 2 to participate in the three-phase separation treatment, thereby further recovering the silicone oil in the alkali residue.

[0039] The device for recycling alkali slag and recovering silicone oil provided by the present invention realizes full-process automated control of the alkali slag treatment process through the systematic integrated design of the dissolving kettle 1, the three-phase separator 2, the emulsion buffer tank 3, the centrifugal demulsifier 4 and the brine preparation tank 5, significantly improves the separation efficiency of silicone oil, alkali solution and emulsion, and the arrangement of the centrifugal demulsifier 4 and the brine preparation tank 5 enhances the demulsification effect of the composite brine. The entire device operates stably and reliably and can be produced continuously, which not only greatly improves the recovery rate of silicone oil and alkali solution, but also has low equipment investment and operating costs, simple maintenance, and is adapted to the needs of industrial production, providing efficient equipment support for the resource treatment of alkali slag in the silicone industry.

[0040] Furthermore, it also includes a hot water tank 6 and a brine metering tank 9; the outlet of the hot water tank 6 is connected to the inlet of the dissolution kettle 1 and the inlet of the brine preparation tank 5 respectively, and the outlet of the brine preparation tank 5 is connected to the brine inlet of the centrifugal demulsifier 4 through the brine metering tank 9.

[0041] In one embodiment, the dissolving tank 1 is disposed above the three-phase separator 2, the outlet of the dissolving tank 1 is disposed at the bottom of the dissolving tank 1, and the material inlet of the three-phase separator 2 is disposed at the top of the three-phase separator 2. The dissolved material is transported to the three-phase separator 2 using the principle of static equilibrium, further saving power consumption for transporting the dissolved material.

[0042] Furthermore, the brine preparation tank 5 is equipped with a nitrogen bubbling device to further save energy consumption.

[0043] Optionally, the separated oil phase can be sent to the silicone oil system via the silicone oil recovery tank 7 and the recovery oil pump 8, and the separated alkali solution can be sent to the alkali tank of the silicone oil system.

[0044] Further, see Figure 2 A detachable filter plate 101 is provided in the middle and upper part of the dissolving kettle 1 for filtering mechanical impurities and adhesives in the alkali residue.

[0045] It is worth noting that the specific structure of the pipelines connecting the various devices is conventional in the art and will not be described in detail here, as long as the process flow is smooth. The present invention does not limit the specific form of each device, which are all existing devices in the art and any device that can achieve its functions can be used.

[0046] Hereinafter, a method for recycling silicone oil by recycling alkali residue provided by the present invention is described in detail through specific examples.

[0047] Example 1

[0048] The alkali residue is passed into the dissolving kettle, and the hot water in the hot water tank is added to the dissolving kettle for stirring and dissolving for 1 hour to obtain the dissolved material;

[0049] The dissolved material in the dissolving kettle is discharged into the three-phase separator for three-phase separation treatment. The alkali liquid at the bottom is discharged into the alkali liquid tank of the silicone oil system for system alkali washing. The oil phase at the top is sent to the silicone oil recovery tank. The material in the silicone oil recovery tank is sent to the silicone oil system for recovery through the recovery oil pump. The silicone oil recovery rate is 100%; the middle emulsified layer is sent to the emulsion buffer tank, and the emulsion in the emulsion buffer tank is sent to the centrifugal demulsifier;

[0050] The composite brine in the brine preparation tank is sodium chloride, potassium chloride and magnesium chloride in a mass ratio of 1:0.2:10, and the temperature of the brine preparation tank is 40°C; after the composite brine is prepared, the brine is sent to the brine metering tank, and the brine in the brine metering tank is sent to a high-efficiency centrifugal demulsifier with a mass of 10% of the emulsion. The composite brine and the emulsion are centrifugally demulsified in the centrifugal demulsifier. The speed of the high-efficiency centrifugal demulsifier is 3000r / min, and the demulsification time is 4 hours. The recovered silicone oil is observed to be colorless and transparent, and is sent to the three-phase separator to participate in the three-phase separation process again.

[0051] Example 2

[0052] The alkali residue is passed into the dissolving kettle, and the hot water in the hot water tank is added to the dissolving kettle for stirring and dissolving for 3 hours to obtain the dissolved material;

[0053] The dissolved material in the dissolving kettle is discharged into the three-phase separator for three-phase separation treatment. The alkali liquid at the bottom is discharged into the alkali liquid tank of the silicone oil system for system alkali washing. The oil phase at the top is sent to the silicone oil recovery tank. The material in the silicone oil recovery tank is sent to the silicone oil system for recovery through the recovery oil pump. The silicone oil recovery rate is 100%; the middle emulsified layer is sent to the emulsion buffer tank, and the emulsion in the emulsion buffer tank is sent to the centrifugal demulsifier;

[0054] The composite brine in the brine preparation tank is sodium chloride, potassium chloride and magnesium chloride in a mass ratio of 1:0.7:10, and the temperature of the brine preparation tank is 85°C; after the composite brine is prepared, the brine is sent to the brine metering tank, and the brine in the brine metering tank is sent to a high-efficiency centrifugal demulsifier with a mass of 30% of the emulsion. The composite brine and the emulsion are centrifugally demulsified in the centrifugal demulsifier. The speed of the high-efficiency centrifugal demulsifier is 5000r / min, and the demulsification time is 7 hours. The recovered silicone oil is observed to be colorless and transparent, and is sent to the three-phase separator to participate in the three-phase separation process again.

[0055] Example 3

[0056] The alkali residue is passed into the dissolving kettle, and the hot water in the hot water tank is added to the dissolving kettle for stirring and dissolving for 2 hours to obtain the dissolved material;

[0057] The dissolved material in the dissolving kettle is discharged into the three-phase separator for three-phase separation treatment. The alkali liquid at the bottom is discharged into the alkali liquid tank of the silicone oil system for system alkali washing. The oil phase at the top is sent to the silicone oil recovery tank. The material in the silicone oil recovery tank is sent to the silicone oil system for recovery through the recovery oil pump. The silicone oil recovery rate is 100%; the middle emulsified layer is sent to the emulsion buffer tank, and the emulsion in the emulsion buffer tank is sent to the centrifugal demulsifier;

[0058] The composite brine in the brine preparation tank is sodium chloride, potassium chloride and magnesium chloride in a mass ratio of 1:0.5:15, and the temperature of the brine preparation tank is 40°C; after the composite brine is prepared, the brine is sent to the brine metering tank, and the brine in the brine metering tank is sent to a high-efficiency centrifugal demulsifier with a mass of 10% of the emulsion. The composite brine and the emulsion are centrifugally demulsified in the centrifugal demulsifier. The speed of the high-efficiency centrifugal demulsifier is 3000r / min, and the demulsification time is 4 hours. The recovered silicone oil is observed to be colorless and transparent, and is sent to the three-phase separator to participate in the three-phase separation process again.

[0059] Example 4

[0060] The alkali residue is passed into the dissolving kettle, and the hot water in the hot water tank is added to the dissolving kettle for stirring and dissolving for 2 hours to obtain the dissolved material;

[0061] The dissolved material in the dissolving kettle is discharged into the three-phase separator for three-phase separation treatment. The alkali liquid at the bottom is discharged into the alkali liquid tank of the silicone oil system for system alkali washing. The oil phase at the top is sent to the silicone oil recovery tank. The material in the silicone oil recovery tank is sent to the silicone oil system for recovery through the recovery oil pump. The silicone oil recovery rate is 100%; the middle emulsified layer is sent to the emulsion buffer tank, and the emulsion in the emulsion buffer tank is sent to the centrifugal demulsifier;

[0062] The composite brine in the brine preparation tank is sodium chloride, potassium chloride and magnesium chloride in a mass ratio of 1:0.5:15, and the temperature of the brine preparation tank is 85°C; after the composite brine is prepared, the brine is sent to the brine metering tank, and the brine in the brine metering tank is sent to a high-efficiency centrifugal demulsifier with a mass of 10% of the emulsion. The composite brine and the emulsion are centrifugally demulsified in the centrifugal demulsifier. The speed of the high-efficiency centrifugal demulsifier is 3000r / min, and the demulsification time is 4 hours. The recovered silicone oil is observed to be colorless and transparent, and is sent to the three-phase separator to participate in the three-phase separation process again.

[0063] Example 5

[0064] The alkali residue is passed into the dissolving kettle, and the hot water in the hot water tank is added to the dissolving kettle for stirring and dissolving for 2 hours to obtain the dissolved material;

[0065] The dissolved material in the dissolving kettle is discharged into the three-phase separator for three-phase separation treatment. The alkali liquid at the bottom is discharged into the alkali liquid tank of the silicone oil system for system alkali washing. The oil phase at the top is sent to the silicone oil recovery tank. The material in the silicone oil recovery tank is sent to the silicone oil system for recovery through the recovery oil pump. The silicone oil recovery rate is 100%; the middle emulsified layer is sent to the emulsion buffer tank, and the emulsion in the emulsion buffer tank is sent to the centrifugal demulsifier;

[0066] The composite brine in the brine preparation tank is sodium chloride, potassium chloride and magnesium chloride in a mass ratio of 1:0.5:15, and the temperature of the brine preparation tank is 65°C; after the composite brine is prepared, the brine is sent to the brine metering tank, and the brine in the brine metering tank is sent to a high-efficiency centrifugal demulsifier with a mass of 10% of the emulsion. The composite brine and the emulsion are centrifugally demulsified in the centrifugal demulsifier. The speed of the high-efficiency centrifugal demulsifier is 3000r / min, and the demulsification time is 4 hours. The recovered silicone oil is observed to be colorless and transparent, and is sent to the three-phase separator to participate in the three-phase separation process again.

[0067] Example 6

[0068] The alkali residue is passed into the dissolving kettle, and the hot water in the hot water tank is added to the dissolving kettle for stirring and dissolving for 2 hours to obtain the dissolved material;

[0069] The dissolved material in the dissolving kettle is discharged into the three-phase separator for three-phase separation treatment. The alkali liquid at the bottom is discharged into the alkali liquid tank of the silicone oil system for system alkali washing. The oil phase at the top is sent to the silicone oil recovery tank. The material in the silicone oil recovery tank is sent to the silicone oil system for recovery through the recovery oil pump. The silicone oil recovery rate is 100%; the middle emulsified layer is sent to the emulsion buffer tank, and the emulsion in the emulsion buffer tank is sent to the centrifugal demulsifier;

[0070] The composite brine in the brine preparation tank is sodium chloride, potassium chloride and magnesium chloride in a mass ratio of 1:0.5:15, and the temperature of the brine preparation tank is 65°C; after the composite brine is prepared, the brine is sent to the brine metering tank, and the brine in the brine metering tank is sent to a high-efficiency centrifugal demulsifier with a mass of 30% of the emulsion. The composite brine and the emulsion are centrifugally demulsified in the centrifugal demulsifier. The speed of the high-efficiency centrifugal demulsifier is 3000r / min, and the demulsification time is 4 hours. The recovered silicone oil is observed to be colorless and transparent, and is sent to the three-phase separator to participate in the three-phase separation process again.

[0071] Example 7

[0072] The alkali residue is passed into the dissolving kettle, and the hot water in the hot water tank is added to the dissolving kettle for stirring and dissolving for 2 hours to obtain the dissolved material;

[0073] The dissolved material in the dissolving kettle is discharged into the three-phase separator for three-phase separation treatment. The alkali liquid at the bottom is discharged into the alkali liquid tank of the silicone oil system for system alkali washing. The oil phase at the top is sent to the silicone oil recovery tank. The material in the silicone oil recovery tank is sent to the silicone oil system for recovery through the recovery oil pump. The silicone oil recovery rate is 100%; the middle emulsified layer is sent to the emulsion buffer tank, and the emulsion in the emulsion buffer tank is sent to the centrifugal demulsifier;

[0074] The composite brine in the brine preparation tank is sodium chloride, potassium chloride and magnesium chloride in a mass ratio of 1:0.5:15, and the temperature of the brine preparation tank is 65°C; after the composite brine is prepared, the brine is sent to the brine metering tank, and the brine in the brine metering tank is sent to a high-efficiency centrifugal demulsifier with a mass of 30% of the emulsion. The composite brine and the emulsion are centrifugally demulsified in the centrifugal demulsifier. The speed of the high-efficiency centrifugal demulsifier is 5000r / min, and the demulsification time is 4 hours. The recovered silicone oil is observed to be colorless and transparent, and is sent to the three-phase separator to participate in the three-phase separation process again.

[0075] Example 8

[0076] The alkali residue is passed into the dissolving kettle, and the hot water in the hot water tank is added to the dissolving kettle for stirring and dissolving for 2 hours to obtain the dissolved material;

[0077] The dissolved material in the dissolving kettle is discharged into the three-phase separator for three-phase separation treatment. The alkali liquid at the bottom is discharged into the alkali liquid tank of the silicone oil system for system alkali washing. The oil phase at the top is sent to the silicone oil recovery tank. The material in the silicone oil recovery tank is sent to the silicone oil system for recovery through the recovery oil pump. The silicone oil recovery rate is 100%; the middle emulsified layer is sent to the emulsion buffer tank, and the emulsion in the emulsion buffer tank is sent to the centrifugal demulsifier;

[0078] The composite brine in the brine preparation tank is sodium chloride, potassium chloride and magnesium chloride in a mass ratio of 1:0.5:15, and the temperature of the brine preparation tank is 65°C; after the composite brine is prepared, the brine is sent to the brine metering tank, and the brine in the brine metering tank is sent to a high-efficiency centrifugal demulsifier with a mass of 20% of the emulsion. The composite brine and the emulsion are centrifugally demulsified in the centrifugal demulsifier. The speed of the high-efficiency centrifugal demulsifier is 4000r / min, and the demulsification time is 4 hours. The recovered silicone oil is observed to be colorless and transparent, and is sent to the three-phase separator to participate in the three-phase separation process again.

[0079] Example 9

[0080] The alkali residue is passed into the dissolving kettle, and the hot water in the hot water tank is added to the dissolving kettle for stirring and dissolving for 2 hours to obtain the dissolved material;

[0081] The dissolved material in the dissolving kettle is discharged into the three-phase separator for three-phase separation treatment. The alkali liquid at the bottom is discharged into the alkali liquid tank of the silicone oil system for system alkali washing. The oil phase at the top is sent to the silicone oil recovery tank. The material in the silicone oil recovery tank is sent to the silicone oil system for recovery through the recovery oil pump. The silicone oil recovery rate is 100%; the middle emulsified layer is sent to the emulsion buffer tank, and the emulsion in the emulsion buffer tank is sent to the centrifugal demulsifier;

[0082] The composite brine in the brine preparation tank is sodium chloride, potassium chloride and magnesium chloride in a mass ratio of 1:0.5:15, and the temperature of the brine preparation tank is 65°C; after the composite brine is prepared, the brine is sent to the brine metering tank, and the brine in the brine metering tank is sent to a high-efficiency centrifugal demulsifier with a mass of 20% of the emulsion. The composite brine and the emulsion are centrifugally demulsified in the centrifugal demulsifier. The speed of the high-efficiency centrifugal demulsifier is 4000r / min, and the demulsification time is 7 hours. The recovered silicone oil is observed to be colorless and transparent, and is sent to the three-phase separator to participate in the three-phase separation process again.

[0083] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. If these modifications and variations fall within the scope of the claims of the present invention and their equivalent technologies, they should be considered to be within the scope of protection of the present invention.

Claims

1. A method for recycling silicone oil by recycling alkali residue, characterized in that: The following steps are involved: Stirring and dissolving the alkali residue to obtain dissolved material; The dissolved material is subjected to three-phase separation treatment to obtain an alkali solution in the lower layer, an oil phase in the upper layer, and an emulsion in the middle layer; wherein the alkali solution is used for alkali washing and recycling, and the oil phase is used for silicone oil recycling; Compound salt water is added to the emulsion for centrifugal demulsification treatment to obtain recovered silicone oil and wastewater; the recovered silicone oil is re-involved in the three-phase separation treatment; wherein the compound salt water includes sodium salt, potassium salt and magnesium salt.

2. The method for recycling silicone oil by recycling alkali residue according to claim 1, characterized in that: The stirring and dissolving treatment time is 1~3h, the stirring speed is 30~50rpm, and the temperature is 55~75℃.

3. The method for recycling silicone oil by recycling alkali residue according to claim 1, characterized in that: The preparation temperature of the composite brine is 40~85℃.

4. The method for recycling silicone oil by recycling alkali residue according to claim 1, characterized in that: During the preparation of the composite brine, nitrogen is introduced for bubbling treatment at a rate of 5-30 m³ / h.

5. The method for recycling silicone oil by recycling alkali residue according to any one of claims 1 to 4, characterized in that: The mass ratio of sodium salt, potassium salt and magnesium salt is 1: (0.2-0.7): (10-20).

6. The method for recycling silicone oil by recycling alkali residue according to claim 5, characterized in that: In the centrifugal demulsification treatment, the mass ratio of the emulsion to the composite brine is 10:(1~3).

7. The method for recycling silicone oil by recycling alkali residue according to claim 6, characterized in that: The sodium salt includes at least one of sodium chloride, sodium carbonate, sodium fatty alcohol alkyl sulfonate, sodium sulfate and sodium nitrate; and / or, The potassium salt includes at least one of potassium chloride, potassium carbonate, potassium sulfate or potassium nitrate; and / or, The magnesium salt includes at least one of magnesium chloride, magnesium nitrate or magnesium sulfate.

8. The method for recycling silicone oil by recycling alkali residue according to any one of claims 1 to 4, characterized in that: The speed of centrifugal demulsification treatment is 3000~5000r / min, and the time is 4~7h.

9. A device for recycling silicone oil from alkali residue, used for executing the method for recycling silicone oil from alkali residue according to any one of claims 1 to 8, characterized in that: It includes dissolving kettle, three-phase separator, emulsion buffer tank, centrifugal demulsifier and brine preparation tank; Among them, the alkali residue is introduced into the material inlet of the dissolution kettle, the outlet of the dissolution kettle is connected with the material inlet of the three-phase separator, the alkali liquid outlet at the bottom of the three-phase separator is used to output the alkali liquid, the oil phase outlet at the top of the three-phase separator is used to output the oil phase, the emulsion outlet in the middle of the three-phase separator is connected with the inlet of the emulsion buffer tank, the outlet of the emulsion buffer tank is connected with the material inlet of the centrifugal demulsifier, the outlet of the brine preparation tank is connected with the brine inlet of the centrifugal demulsifier, the silicone oil outlet of the centrifugal demulsifier is connected with the reflux port of the three-phase separator, and the wastewater outlet of the centrifugal demulsifier is used for drainage.

10. The device for recycling silicone oil from alkali residue according to claim 9, characterized in that: Also includes hot water tanks and brine metering tanks; The outlet of the hot water tank is communicated with the inlet of the dissolving kettle and the inlet of the brine preparation tank respectively. The outlet of the brine preparation tank is communicated with the brine inlet of the centrifugal demulsifier through the brine metering tank.

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