Treatment system and treatment method for concentrating and separating salty mud in primary brine refining process

Abstract

The invention relates to the technical field of primary brine treatment processes, and particularly discloses a salt mud concentration and separation treatment system and method in a primary brine refining process, and the system comprises a salt mud pool, a salt mud pump, a salt mud concentration separator, an HVMTM membrane filter, a primary brine storage tank, a filter press and a DCS control module, the method comprises the following steps: feeding a salty mud mixed solution into a salty mud concentration separator for separation and concentration, carrying out salty mud concentration and sedimentation separation through a special structure of the salty mud concentration separator, directly feeding a clear solution into an HVMTM membrane filter for filtration, feeding the filtered clear solution into a primary salty water storage tank, and treating a concentrated salty mud solution at the bottom of the salty mud concentration separator through a salty mud filter press; according to the technology, about 40-50% of salt water in the salt mud mixed liquid can be directly filtered through the HVM membrane, so that the secondary consumption of a refining agent in the primary salt water treatment process is reduced, and the salt water refining cost is reduced; the salty mud treatment efficiency is improved, and the treatment burden of the filter press is reduced by about 40%.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of primary brine treatment process, in particular to a salt sludge concentration and separation treatment system and method in the primary brine refining process. BACKGROUND

[0002] In the primary brine refining process, the sludge of the Kay membrane and the inorganic ceramic membrane, the backflush waste liquid of the coarse filter, and the salt-containing waste liquid discharged during the maintenance of the primary brine equipment and pipelines are collected into a salt sludge mixed liquid storage tank and directly sent to a filter press for treatment by a pressurizing pump. However, the salt sludge mixed liquid recovered from the salt sludge pool contains salt indexes, excessive sodium hydroxide, and excessive sodium carbonate indexes, which meet the daily control indexes of the primary brine. After being directly treated by the filter press, the filtered liquid is sent to the salt-making water system again for salt-making, which not only increases the treatment burden of the filter press, but also increases the consumption of refining agents and the treatment load in the refining process, increases the production cost, and wastes resources and energy.

[0003] The existing salt sludge mixed liquid treatment process in the chlor-alkali industry has the following problems: 1. The traditional salt sludge mixed liquid treatment process increases the treatment burden of the filter press. 2. The filtered liquid after filtration is saturated brine, which contains excessive sodium hydroxide and excessive sodium carbonate indexes and returns to the salt-making system again, thereby increasing the consumption of refining agents in the refining process and increasing the treatment cost. SUMMARY

[0004] To solve the above technical problems, the present application provides a salt sludge concentration and separation treatment system and method in the primary brine refining process. The salt sludge mixed liquid is sent to a salt sludge concentration and separation device for separation and concentration. The salt sludge is concentrated and separated by the special structure of the salt sludge concentration and separation device. The clear liquid is directly filtered by the Kay membrane filter and then sent to the primary brine storage tank. The concentrated salt sludge liquid at the bottom of the salt sludge concentration and separation device is treated by a salt sludge filter press. Through this technology, about 40-50% of the salt water in the salt sludge mixed liquid can be directly filtered by the Kay membrane, thereby reducing the secondary consumption of refining agents in the primary brine treatment process, reducing the cost of brine refining, improving the salt sludge treatment efficiency, and reducing the treatment burden of the filter press by about 40%.

[0005] To achieve this technical purpose, the present application adopts the following scheme: In a first aspect, the present application provides a salt sludge concentration and separation treatment system in the primary brine refining process, which comprises a salt sludge pool, a salt sludge pump, a filter press, and a DCS control module. The salt sludge pool is connected with a salt sludge concentration and separation device through a salt sludge pipeline. The salt sludge concentration and separation device is connected with the filter press through a concentrated salt sludge pipeline. The salt sludge concentration and separation device is connected with a Kay membrane filter through a clear liquid outlet pipeline. The Kay membrane filter is connected with a primary brine storage tank.

[0006] Further, the salt sludge pipeline is connected with a liquid inlet pipeline, and a remote flow meter and a regulating valve are installed on the liquid inlet pipeline, and the remote flow meter and the regulating valve are respectively connected with the DCS control module in communication.

[0007] Further, the top of the salt sludge concentration separator is provided with a salt sludge liquid inlet, and the middle is provided with a inclined plate layer; the liquid inlet pipeline is provided with a plurality of liquid inlet pipelines, which are uniformly distributed at the salt sludge liquid inlet of the salt sludge concentration separator and extend to the inclined plate layer; the upper part of the salt sludge concentration separator is provided with a clear liquid outlet connected with a clear liquid outlet pipeline; the bottom of the salt sludge concentration separator is provided with a concentrated salt sludge outlet connected with a concentrated salt sludge pipeline.

[0008] Further, the salt sludge pipeline is provided with a salt sludge pump A, a salt sludge flow meter and a salt sludge regulating valve, and the salt sludge flow meter and the salt sludge regulating valve are respectively connected with the DCS control module in communication.

[0009] Further, the concentrated salt sludge pipeline is provided with a salt sludge pump B, a concentrated salt sludge flow meter and a concentrated salt sludge regulating valve, and the concentrated salt sludge flow meter and the concentrated salt sludge regulating valve are respectively connected with the DCS control module in communication.

[0010] Further, the clear liquid outlet pipeline is provided with a salt content monitor, a clear liquid flow meter and a forward osmosis membrane cut-off valve, and the salt content monitor, the clear liquid flow meter and the forward osmosis membrane cut-off valve are respectively connected with the DCS control module in communication.

[0011] Further, the clear liquid outlet pipeline is connected with a coarse salt water tank through a pipeline, and an unqualified salt water cut-off valve is arranged on the connecting pipeline, and the unqualified salt water cut-off valve is connected with the DCS control module in communication.

[0012] In the second aspect, the application provides a salt sludge concentration separation treatment method in a primary brine refining process, which is performed according to the following steps: Step one, the salt sludge is transported to the salt sludge concentration separator by the salt sludge pump A, and the salt sludge concentration separator performs concentration separation on the salt sludge mixed liquid; Step two, after the concentration separation of the salt sludge concentration separator, the bottom concentrated salt sludge is sent into the filter press through the concentrated salt sludge pipeline by the salt sludge pump B for pressure filtration treatment; and the upper separated qualified supernatant enters the forward osmosis filter for filtration; The salt sludge flow entering the salt sludge concentration separator is monitored by the salt sludge flow meter, and is controlled by the DCS control module; the concentrated salt sludge flow discharged from the salt sludge concentration separator is monitored by the concentrated salt sludge flow meter, and is controlled by the DCS control module; the clear liquid outlet flow and the salt content discharged from the salt sludge concentration separator are monitored by the clear liquid flow meter and the salt content monitor respectively, and the supernatant flow is controlled by the DCS control module.

[0013] Further, when the salt content monitoring value is lower than the set lower limit 300g / L, it is judged that the salt content index is unqualified, the DCS control module opens the unqualified salt water cut-off valve to the coarse salt water tank, closes the into the membrane cut-off valve, and the unqualified salt water reenters the coarse salt water tank, and the salt treatment is carried out again to ensure that the salt content index of the primary salt water is stable and qualified.

[0014] Further, the sum of the clear liquid outlet flow of the salt mud concentration separator and the concentrated salt mud flow is equal to the salt mud flow into the salt mud concentration separator, and the 'concentrated salt mud flow / salt mud flow' is recorded as a K coefficient, the salt mud concentration ratio and the separated clear liquid amount are controlled by adjusting the K coefficient, and the K coefficient is controlled at 0.4-0.7.

[0015] Compared with the prior art, the beneficial effects of the present application are that: The salt mud mixed liquid after the ceramic membrane, the pre-treater discharge mud and the membrane discharge residue is sent to the salt mud concentration separator for separation and concentration, the treated clear liquid is directly sent to the primary salt water storage tank after being filtered by the membrane filter, and the concentrated salt mud liquid at the bottom of the salt mud concentration separator is sent to the filter press for treatment, about 40-50% of the salt water in the salt mud mixed liquid can be directly filtered by the membrane, the secondary consumption of the refining agent in the primary salt water treatment process is reduced, the salt water refining cost is reduced, the salt mud treatment efficiency is improved, and the treatment burden of the filter press is reduced. BRIEF DESCRIPTION OF DRAWINGS

[0016] Fig. 1 A salt mud concentration and separation treatment system in a primary salt water refining process is provided for the embodiments of the present application; Fig. 2 A logic block diagram of a salt mud concentration and separation treatment method in a primary salt water refining process is provided for the embodiments of the present application; Fig. 3 A structure schematic diagram of a salt mud concentration separator is provided for the embodiments of the present application; In the figure, 1 is a salt mud pool, 2 is a salt mud pump A, 3 is a salt mud pipeline, 4 is a salt mud flow meter, 5 is a salt mud regulating valve, 6 is an inlet pipeline, 7 is a salt mud concentration separator, 71 is a salt mud liquid inlet, 72 is a sedimentation inclined plate, 73 is a clear liquid outlet, 74 is a concentrated salt mud outlet, 8 is a salt content monitor, 9 is a clear liquid flow meter, 10 is a clear liquid outlet pipeline, 11 is an unqualified salt water cut-off valve, 12 is a primary salt water storage tank, 13 is a coarse salt water tank, 14 is a membrane filter, 15 is a filter press, 16 is a concentrated salt mud regulating valve, 17 is a concentrated salt mud flow meter, 18 is a salt mud pump B, 19 is an into the membrane cut-off valve, 20 is a concentrated salt mud pipeline, and 21 is a DCS control module. DETAILED DESCRIPTION

[0017] In order to fully understand the objects, features and effects of the present application, the following specific embodiments are described in detail, but the present application is not limited to this.

[0018] Referring to Figs. 1 to 3 The embodiment of the present application provides a salt mud concentration and separation treatment system in a primary brine refining process, which comprises a salt mud pool 1, a salt mud pump A 2, a salt mud pipeline 3, a salt mud flowmeter 4, a salt mud regulating valve 5, a liquid inlet pipeline 6, a salt mud concentration and separation device 7, a salt content monitor 8, a clear liquid flowmeter 9, a clear liquid outlet pipeline 10, an unqualified brine cut-off valve 11, a primary brine storage tank 12, a coarse brine tank 13, a Kaimai filter 14, a filter press 15, a concentrated salt mud regulating valve 16, a concentrated salt mud flowmeter 17, a salt mud pump B 18, a Kaimai inlet cut-off valve 19, a concentrated salt mud pipeline 20 and a DCS control module 21.

[0019] The salt mud pool 1 is communicated with the salt mud pump A 2 through a pipeline, the salt mud pump A 2 is communicated with the salt mud concentration and separation device 7 through the salt mud pipeline 3, the salt mud pipeline 3 is provided with the salt mud flowmeter 4 and the salt mud regulating valve 5, and the salt mud flowmeter 4 and the salt mud regulating valve 5 are respectively connected with the DCS control module 21 in communication.

[0020] The salt mud pipeline 3 is connected with the salt mud concentration and separation device 7 through the liquid inlet pipeline 6, the liquid inlet pipeline 6 is composed of a plurality of DN32 and DN25 pipelines which are uniformly distributed, so that the salt mud mixture can enter the salt mud concentration and separation device 7 uniformly, and the disturbance caused by liquid inlet is prevented, and the sedimentation and separation effect of the salt mud concentration and separation device 7 is prevented from being damaged.

[0021] The liquid inlet pipeline 6 is provided with a remote flowmeter and a regulating valve, and the remote flowmeter and the regulating valve are respectively connected with the DCS control module 21 in communication.

[0022] Referring to Fig. 3 The top of the salt mud concentration and separation device 7 is provided with a salt mud liquid inlet 71, and the middle part is provided with an inclined plate layer, the inclined plate layer comprises a plurality of uniformly distributed sedimentation inclined plates 72 for reducing flow rate and collecting sedimentation salt mud; the plurality of DN32 and DN25 pipelines of the liquid inlet pipeline 6 are uniformly distributed at the salt mud liquid inlet 71 of the salt mud concentration and separation device 7 and extend to the inclined plate layer, the flow rate is reduced by the sedimentation inclined plate 72, and the sedimentation and separation speed and quality of the salt mud are improved. The top of the salt mud concentration and separation device 7 is in the shape of a trumpet mouth, the large mouth is downward, 4-5 clear liquid outlets 73 are arranged on the arc-shaped periphery for collecting separated supernatant, and the clear liquid outlets 73 are connected with the clear liquid outlet pipeline 10.

[0023] The lower part of the salt mud concentration and separation device 7 is in a conical structure, the bottom of the conical structure is provided with a concentrated salt mud outlet 74, and the concentrated salt mud outlet 74 is connected with the concentrated salt mud pipeline 20.

[0024] The concentrated salt sludge pipeline 20 is connected with the salt sludge pump B 18, the salt sludge pump B 18 is connected with the filter press 15, the concentrated salt sludge regulating valve 16 and the concentrated salt sludge flowmeter 17 are installed on the pipeline between the outlet of the salt sludge pump B 18 and the filter press 15, and the concentrated salt sludge regulating valve 16 and the concentrated salt sludge flowmeter 17 are respectively connected with the DCS control module 21.

[0025] The salt sludge concentration separator 7 is connected with the coarse salt water tank 13 and the membrane filter 14 through the clear liquid outlet pipe 10, the membrane filter 14 is connected with the primary brine storage tank 12, the salt content monitor 8 and the clear liquid flowmeter 9 are installed on the clear liquid outlet pipe 10, the membrane inlet cut-off valve 19 is arranged on the pipeline from the clear liquid outlet pipe 10 to the membrane filter 14, the unqualified salt water cut-off valve 11 is arranged on the pipeline from the clear liquid outlet pipe 10 to the coarse salt water tank 13, and the salt content monitor 8, the clear liquid flowmeter 9, the unqualified salt water cut-off valve 11 and the membrane inlet cut-off valve 19 are respectively connected with the DCS control module 21.

[0026] Referring to Fig. 2 A salt sludge concentration separation treatment method in a primary brine refining process, the salt content in the clear liquid is monitored by the salt content monitor 8, and the detection result is introduced into the DCS control module 21; the DCS control module 21 controls the unqualified salt water cut-off valve 11 and the membrane inlet cut-off valve 19 to switch through the set value, so that the salt sludge concentration separator 7 separates the clear clear liquid into different process treatment flows. The salt sludge flowmeter 4, the salt sludge regulating valve 5, the clear liquid flowmeter 9, the concentrated salt sludge regulating valve 16 and the concentrated salt sludge flowmeter 17 monitor the flow in and out of the salt sludge concentration separator 7 in real time and transmit the monitoring values to the DCS control module 21; the DCS control module 21 processes and analyzes the data, controls the opening degree of the regulating valve in and out of the salt sludge concentration separator 7, balances the control processing load, and makes the medium flow in and out of the salt sludge concentration separator 7 in a dynamic balance state, which is specifically performed according to the following steps: Step one, the salt sludge is transported to the salt sludge concentration separator 7 by the salt sludge pump A 2, the salt sludge concentration separator 7 concentrates and separates the salt sludge mixed liquid, the salt sludge mixed liquid settles in the salt sludge concentration separator 7, the salt sludge slurry with large particles is heavy and enters the lower part of the salt sludge concentration separator 7, and the clear liquid enters the upper part of the salt sludge concentration separator 7; Step two, after the concentration and separation of the salt sludge concentration separator 7, the concentrated salt sludge at the bottom is sent to the filter press 15 through the concentrated salt sludge pipeline 20 by the salt sludge pump B 18 for filter pressing treatment; the qualified supernatant separated from the upper part enters the membrane filter 14 for filtration; When the monitoring value of the salt content monitor 8 is lower than the set lower limit 300g / L, it is judged that the salt content index is unqualified, the DCS control module 21 opens the unqualified salt water cut-off valve 11 to the coarse salt water tank 13 and closes the membrane inlet cut-off valve 19, and the unqualified salt water reenters the coarse salt water tank 13 for salt treatment again, so as to ensure that the salt content index of the primary brine is stable and qualified.

[0027] The sum of the clear liquid outflow of the salt sludge concentration separator 7 and the concentrated salt sludge flow is equal to the salt sludge flow into the salt sludge concentration separator 7, so as to effectively control the processing load of the salt sludge concentration separator 7.

[0028] The ratio of the concentrated salt sludge flow to the salt sludge flow is denoted as a K coefficient, the K coefficient is adjusted to control the salt sludge concentration ratio and the separation clear liquid amount, the K coefficient can be adjusted according to production requirements, and is generally controlled between 0.4 and 0.7. The size of the K coefficient directly affects the clear liquid recovery amount and the concentrated salt sludge amount, and is an important setting parameter of the process. When the K coefficient is less than 0.4, the lower the concentrated salt sludge flow, the greater the clear liquid flow, the sedimentation separation effect is low, which is not conducive to salt water quality control; when the K coefficient is greater than 0.7, the concentrated salt sludge flow is large, and the clear liquid flow is small, and the separation and recovery of salt water is reduced.

[0029] The salt sludge is subjected to sedimentation separation through the processing system and the processing method provided by the application, about 40-50% of the salt water in the salt sludge mixed solution can be directly filtered through the Kay membrane filter 14, the secondary consumption of the refining agent in the primary salt water treatment process is reduced, the salt water refining cost is reduced, the salt sludge treatment efficiency is improved, and the processing burden of the filter press 15 is reduced.

[0030] Finally, it should be noted that: the above-mentioned is only the preferred embodiment of the present application, of course, the person skilled in the art can modify and change the present application, if these modifications and changes belong to the scope of the present application claim and its equivalent technology, should be considered as the protection scope of the present application.

Claims

1. A system for concentrating and separating salt slurry in a primary brine refining process, comprising a salt slurry tank (1), a salt slurry pump, a filter press (15) and a DCS control module (21), characterized in that, The salt sludge tank (1) is connected with a salt sludge concentration separator (7) through a salt sludge pipeline (3), the salt sludge concentration separator (7) is connected with a filter press (15) through a concentrated salt sludge pipeline (20), the salt sludge concentration separator (7) is connected with a Kaimai filter (14) through a clear liquid outlet pipeline (10), and the Kaimai filter (14) is connected with a primary brine storage tank (12).

2. The system for concentrating and separating salt sludge in a primary brine refining process according to claim 1, wherein A liquid inlet pipeline (6) is connected between the salt sludge pipeline (3) and the salt sludge concentration separator (7), a remote flow meter and an adjusting valve are installed on the liquid inlet pipeline (6), and the remote flow meter and the adjusting valve are respectively in communication connection with a DCS control module (21).

3. The system for concentrating and separating salt sludge in a primary brine refining process according to claim 2, wherein The top of the salt sludge concentration separator (7) is provided with a salt sludge liquid inlet (71), and the middle is provided with a tilting plate layer; the liquid inlet pipeline (6) is provided with a plurality of liquid inlet pipelines, which are uniformly distributed at the salt sludge liquid inlet (71) of the salt sludge concentration separator (7) and extend to the tilting plate layer; the upper part of the salt sludge concentration separator (7) is provided with a clear liquid outlet (73), and the clear liquid outlet (73) is connected with the clear liquid outlet pipeline (10); the bottom of the salt sludge concentration separator (7) is provided with a concentrated salt sludge outlet (74), and the concentrated salt sludge outlet (74) is connected with the concentrated salt sludge pipeline (20).

4. The system for concentrating and separating salt sludge in a primary brine refining process according to claim 1, wherein The salt sludge pipeline (3) is provided with a salt sludge pump A (2), a salt sludge flow meter (4) and a salt sludge adjusting valve (5), and the salt sludge flow meter (4) and the salt sludge adjusting valve (5) are respectively in communication connection with a DCS control module (21).

5. The system for concentrating and separating salt sludge in a primary brine refining process according to claim 1, wherein The concentrated salt sludge pipeline (20) is provided with a salt sludge pump B (18), a concentrated salt sludge flow meter (17) and a concentrated salt sludge adjusting valve (16), and the concentrated salt sludge flow meter (17) and the concentrated salt sludge adjusting valve (16) are respectively in communication connection with a DCS control module (21).

6. The system for concentrating and separating salt sludge in a primary brine refining process according to claim 1, wherein The clear liquid outlet pipeline (10) is provided with a salt content monitor (8), a clear liquid flow meter (9) and a Kaimai membrane cut-off valve (19), and the salt content monitor (8), the clear liquid flow meter (9) and the Kaimai membrane cut-off valve (19) are respectively in communication connection with a DCS control module (21).

7. The system for concentrating and separating salt sludge in a primary brine refining process according to claim 1, wherein The clear liquid outlet pipeline (10) is connected with a coarse brine tank (13) through a pipeline, and an unqualified brine cut-off valve (11) is arranged on the connecting pipeline, and the unqualified brine cut-off valve (11) is in communication connection with a DCS control module (21).

8. A method for concentrating and separating salt sludge in a primary brine refining process, characterized by, The following steps are taken: Step one, the salt sludge is transported to the salt sludge concentration separator (7) by the salt sludge pump A (2), and the salt sludge concentration separator (7) concentrates and separates the salt sludge mixture; Step two, after the concentration and separation of the salt sludge concentration separator (7), the bottom concentrated salt sludge is sent into the filter press (15) through the concentrated salt sludge pipeline (20) by the salt sludge pump B (18) for pressure filtration treatment; the qualified supernatant separated from the upper part enters the Kaimai filter (14) for filtration; The salt mud flow into the salt mud concentration separator (7) is monitored by a salt mud flow meter (4) and controlled by the DCS control module (21); the concentrated salt mud flow discharged from the salt mud concentration separator (7) is monitored by a concentrated salt mud flow meter (17) and controlled by the DCS control module (21); the supernatant liquid flow and the salt content discharged from the salt mud concentration separator (7) are monitored by a supernatant liquid flow meter (9) and a salt content monitor (8) respectively, and the supernatant liquid flow is controlled by the DCS control module (21).

9. The method of claim 8, wherein the concentration and separation of the salt sludge in the primary brine refining process is characterized by, When the monitoring value of the salt content monitor (8) is lower than the set lower limit of 300 g / L, it is judged that the salt content index is unqualified, the DCS control module (21) opens the unqualified brine cut-off valve (11) to the coarse salt tank (13), closes the Kaimen cut-off valve (19), and the unqualified brine reenters the coarse salt tank (13) to be treated again to ensure that the salt content index of the primary brine is stable and qualified.

10. The method for concentrating and separating salt sludge in a primary brine refining process according to claim 8, characterized by, The sum of the supernatant liquid flow and the concentrated salt mud flow of the salt mud concentration separator (7) is equal to the salt mud flow into the salt mud concentration separator (7), and the "concentrated salt mud flow / salt mud flow" is recorded as the K coefficient, the K coefficient is controlled to control the salt mud concentration ratio and the separation supernatant liquid amount, and the K coefficient is controlled to be 0.4-0.7.

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