Deamination system and ternary wastewater mother liquor treatment system

Abstract

The utility model relates to the technical field of wastewater treatment, and provides a deamination system and a ternary wastewater mother liquor treatment system. The deamination system comprises a first heat exchanger, a second heat exchanger, a deamination tower, a tail gas absorption tower and a reboiler; an outlet of the cold source channel of the first heat exchanger is communicated with an inlet of the cold source channel of the second heat exchanger, an outlet of the cold source channel of the second heat exchanger is communicated with a feed port of the deamination tower, a gas outlet of the deamination tower is communicated with the tail gas absorption tower, a high-temperature liquid inlet is formed in the middle of the deamination tower, and a stock solution outlet is formed in the bottom of the deamination tower; the stock solution outlet is communicated with an inlet of a cold source channel of the reboiler, and an outlet of the cold source channel of the reboiler is communicated with the high-temperature liquid inlet; a deamination liquid outlet is formed in the bottom of the reboiler and is communicated with an inlet of the heat source channel of the second heat exchanger; and a heat source channel outlet of the reboiler is communicated with a cold source channel inlet of the first heat exchanger. The deamination system can fully utilize the waste heat of condensate water and reduce the energy consumption of the system.

Description

Technical Field

[0001] The utility model relates to the technical field of wastewater treatment, in particular to a deammonification system and a ternary wastewater mother liquor treatment system. Background Art

[0002] Lithium-ion batteries currently occupy a significant market share in the portable electronic device market, thanks to their high specific capacity, long cycle life, low self-discharge rate, lack of memory effect, and environmental friendliness. They are widely recognized as the most promising power battery for electric vehicles. Ternary nickel-cobalt-manganese cathode materials are a key lithium-ion battery cathode material. They offer significant advantages, such as superior performance to lithium cobalt oxide at a significantly lower cost than lithium cobalt oxide, and significantly higher energy density than lithium iron phosphate. They are gradually becoming the mainstream cathode material for automotive power batteries.

[0003] In the preparation process of positive electrode materials, the preparation process of precursors accounts for 60%, and the quality of the precursors directly affects the performance of the positive electrode materials. Generally, ternary positive electrode materials are made by mixing secondary spherical particles formed by the agglomeration of fine crystals of nickel, cobalt, manganese hydroxide and lithium hydroxide and then calcining them. At present, the main method used to produce ternary precursors is the co-precipitation method, that is, nickel salts, cobalt salts, manganese salts or aluminum salts are mixed into salt solutions in a certain proportion, and nickel cobalt manganese / aluminum hydroxide precipitates are formed in the presence of alkaline solution and chelating agents, and then qualified products are obtained through centrifugal washing, slurrying, drying and other steps. In the production of ternary precursor materials, the wastewater in the production process is mainly the mother liquor and washing water generated by the synthesis reaction, aging and washing sections. The wastewater contains pollutants such as ammonia nitrogen, alkali, and heavy metals (nickel, cobalt, manganese).

[0004] Of the two types of wastewater (mother liquor and wash water) treated by conventional ternary wastewater treatment equipment, the mother liquor is deaminated and deweighted (ammonia nitrogen and heavy metals are qualified) and then enters the MVR for evaporation to produce alum and distilled water; the wash water is treated through multi-stage membranes and deammoniation components to produce pure water.

[0005] At present, in the mother liquor treatment system, the steam usage of the deamination system accounts for 60%-70%. During operation, the deamination tower needs to control the top temperature of the tower to about 95°C, the temperature in the tower to about 100°C, and the reboiler temperature to about 105°C. The existing process uses the reboiler outlet water and the deamination tower inlet water for heat exchange, thereby saving steam usage, but the steam condensate discharged from the reboiler and the steam condensate of the MVR are not fully utilized.

[0006] In view of the above problems, the present invention provides a deammonification system, which can utilize the heat in the steam condensate, thereby improving the problem that the thermal energy of the steam condensate is not fully utilized. Utility Model Content

[0007] The purpose of the utility model includes providing a deammonification system and a ternary wastewater mother liquor treatment system, which can utilize the heat in the steam condensate, thereby improving the problem mentioned in the background art that the thermal energy of the steam condensate is not fully utilized.

[0008] The embodiment of the present utility model can be implemented as follows:

[0009] In a first aspect, the utility model provides a deamination system, comprising a first heat exchanger, a second heat exchanger, a deamination tower, a tail gas absorption tower and a reboiler;

[0010] The outlet of the cold source channel of the first heat exchanger is connected to the inlet of the cold source channel of the second heat exchanger, the outlet of the cold source channel of the second heat exchanger is connected to the feed port of the deamination tower, the gas outlet of the deamination tower is connected to the tail gas absorption tower, the middle part of the deamination tower is provided with a high-temperature liquid inlet, the bottom part is provided with a raw liquid outlet, the raw liquid outlet is connected to the inlet of the cold source channel of the reboiler, and the outlet of the cold source channel of the reboiler is connected to the high-temperature liquid inlet;

[0011] The bottom of the reboiler is provided with a deammonification liquid discharge outlet, which is connected to the inlet of the heat source channel of the second heat exchanger; the inlet of the heat source channel of the reboiler is connected to the high-temperature steam inlet pipe, and the outlet of the heat source channel of the reboiler is connected to the inlet of the cold source channel of the first heat exchanger.

[0012] In an optional embodiment, the deamination system further comprises a steam condensate collecting device, and the steam condensate discharge outlet of the reboiler is connected to the inlet of the steam condensate collecting device;

[0013] The deammonification system also includes a falling film evaporator condensate inlet pipe and a forced circulation evaporator steam condensate inlet pipe, and the falling film evaporator condensate inlet pipe and the forced circulation evaporator steam condensate inlet pipe are connected to the inlet of the steam condensate collecting device.

[0014] In an optional embodiment, the outlet of the steam condensate collecting device is connected to the inlet of the heat source channel of the first heat exchanger through a condensate delivery pipe;

[0015] A condensate delivery pump is provided on the condensate delivery pipeline.

[0016] In an optional embodiment, the deammoniation system further includes a weight removal system, and the inlet of the weight removal system is connected to the outlet of the heat source channel of the second heat exchanger.

[0017] In an optional embodiment, the deammoniation system further includes a distilled water system, and the inlet of the distilled water system is connected to the outlet of the heat source channel of the first heat exchanger.

[0018] In an optional embodiment, the first heat exchanger and / or the second heat exchanger is a plate heat exchanger.

[0019] In an optional embodiment, the deammonification system includes an ammonia-containing raw liquid tank, which is connected to the inlet of the cold source channel of the first heat exchanger.

[0020] In an optional embodiment, the ammonia-containing raw liquid tank and the first heat exchanger are connected through a raw liquid delivery pipeline, and a raw liquid delivery pump is provided on the raw liquid delivery pipeline.

[0021] In a second aspect, an embodiment of the present invention provides a ternary wastewater mother liquor treatment system, including the deammoniation system provided by an embodiment of the present invention.

[0022] The beneficial effects of the deamination system provided by the embodiment of the utility model include:

[0023] The deamination system provided by the present invention, due to the first and second heat exchangers, as well as their associated configuration with the reboiler and deamination tower, can recover and utilize the heat in the steam condensate and the deamination liquid, thereby saving energy consumption and reducing processing costs for the entire system. This effectively addresses the issue of insufficient utilization of the heat energy in the steam condensate. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0025] Figure 1 This is a schematic structural diagram of the deamination system provided in this embodiment.

[0026] Icons: 100 - deamination system; 110 - first heat exchanger; 120 - second heat exchanger; 130 - deamination tower; 131 - partition; 132 - feed inlet; 133 - high-temperature liquid inlet; 134 - raw liquid outlet; 135 - deamination liquid outlet; 136 - condenser; 140 - reboiler; 141 - high-temperature steam inlet pipe; 150 - steam condensate collecting device; 151 - falling film evaporator condensate inlet pipe; 152 - forced circulation evaporator steam condensate inlet pipe; 160 - condensate transfer pump; 170 - weight removal system; 180 - distilled water system; 190 - ammonia raw liquid tank; 191 - raw liquid transfer pump. DETAILED DESCRIPTION

[0027] To make the purpose, technical solutions, and advantages of the embodiments 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 accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations.

[0028] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but rather merely represents selected embodiments of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort are intended to fall within the scope of protection of the present invention.

[0029] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not require further definition or explanation in subsequent drawings.

[0030] In the description of the present invention, it should be noted that if the terms "upper", "lower", "inside", "outside", etc. appear, the orientation or position relationship indicated is based on the orientation or position relationship shown in the accompanying drawings, or is the orientation or position relationship in which the utility model product is usually placed when in use. It is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it cannot be understood as a limitation on the present invention.

[0031] In addition, the terms "first", "second", etc., if used, are merely used to distinguish and describe, and should not be understood as indicating or implying relative importance.

[0032] It should be noted that, in the absence of conflict, the features in the embodiments of the present invention can be combined with each other.

[0033] Please refer to Figure 1 As shown, the embodiment of the present invention provides a deamination system 100, comprising a first heat exchanger 110, a second heat exchanger 120, a deamination tower 130, a tail gas absorption tower and a reboiler 140;

[0034] The outlet of the cold source channel of the first heat exchanger 110 is connected to the inlet of the cold source channel of the second heat exchanger 120, the outlet of the cold source channel of the second heat exchanger 120 is connected to the feed inlet 132 of the deamination tower 130, the gas outlet of the deamination tower 130 is connected to the tail gas absorption tower, the deamination tower 130 has a high-temperature liquid inlet 133 in the middle and a raw liquid outlet 134 at the bottom, the raw liquid outlet 134 is connected to the inlet of the cold source channel of the reboiler 140, and the outlet of the cold source channel of the reboiler 140 is connected to the high-temperature liquid inlet 133;

[0035] The bottom of the reboiler 140 is provided with a deammonification liquid discharge outlet 135, which is connected to the inlet of the heat source channel of the second heat exchanger 120; the inlet of the heat source channel of the reboiler 140 is connected to the high-temperature steam inlet pipe 141, and the outlet of the heat source channel of the reboiler 140 is connected to the inlet of the cold source channel of the first heat exchanger 110.

[0036] The method of using the deamination system 100 provided by the present invention is as follows:

[0037] The ammonia-containing raw liquid is introduced into the first heat exchanger 110 from the cold source channel inlet of the first heat exchanger 110 to be heated for the first time, and then enters the cold source channel of the second heat exchanger 120 to be heated for the second time, and then enters the deamination tower 130 from the middle part thereof. The raw liquid entering the deamination tower 130 spreads on the partition 131 provided in the deamination tower 130 and falls downward. The raw liquid falling to the bottom enters the cold source channel of the reboiler 140 and continuously enters the reboiler. Under the heating of the high-temperature steam in the heat source channel 140, the raw liquid in the cold source channel is in a boiling state and enters the deamination tower 130 from the high-temperature liquid inlet 133. After entering the deamination tower 130, the boiling high-temperature mother liquid is released in the form of high-temperature gas, blowing the ammonia nitrogen in the raw liquid distributed on the partition 131 upward and discharged from the gas outlet. The raw liquid after the ammonia nitrogen is removed falls to the bottom of the tower, part of which continues to enter the reboiler 140 for heating and circulation, and part is discharged from the deamination liquid outlet 135. The discharged deamination liquid has a high temperature and is passed into the heat source channel of the first heat exchanger 110 as a heat source to heat the ammonia-containing raw liquid; the steam condensate discharged from the heat source channel of the reboiler 140 still has a high temperature and is passed into the heat source channel of the second heat exchanger 120 as a heat source to heat the ammonia-containing raw liquid again.

[0038] The deamination system 100 provided in the embodiment of the present invention can realize the recovery and utilization of heat in steam condensate and deamination liquid due to the first heat exchanger 110 and the second heat exchanger 120 and their related arrangements with the reboiler 140 and the deamination tower 130, thereby saving energy consumption of the entire system and reducing processing costs.

[0039] It should be noted that, in the present invention, the heat exchanger, deamination tower 130, tail gas absorption tower and reboiler 140 involved all belong to the prior art, and their structures are not described in detail to avoid redundancy.

[0040] Optionally, the heat source channel outlet of the reboiler 140 is connected to the cold source channel inlet of the first heat exchanger 110 through a pipe. To ensure thermal insulation, the pipe is an insulated pipe, or an insulation layer is provided outside the pipe.

[0041] Optionally, the deammonification liquid outlet 135 is connected to the inlet of the heat source channel of the second heat exchanger 120 through a pipe. In order to ensure thermal insulation, the pipe is an insulated pipe, or an insulation layer is provided outside the pipe.

[0042] Optionally, the deamination system 100 further includes a condenser 136 , which is in communication with the gas outlet of the deamination tower 130 and is configured to condense the discharged ammonia gas to obtain ammonia water.

[0043] Optionally, the deamination system 100 further includes a steam condensate collecting device 150 , and the steam condensate discharge port of the reboiler 140 is connected to the inlet of the steam condensate collecting device 150 ;

[0044] The deamination system 100 further includes a falling film evaporator condensate inlet pipe 151 and a forced circulation evaporator steam condensate inlet pipe 152 , which are connected to the inlet of the steam condensate collecting device 150 .

[0045] The condensed water from the falling film evaporator and the steam condensed water from the forced circulation evaporator both have relatively high temperatures. They are collected together with the steam condensed water from the reboiler 140 in the steam condensed water collecting device 150 and introduced into the first heat exchanger 110 as a heat source to further improve the waste heat utilization rate.

[0046] Optionally, the outlet of the steam condensate collecting device 150 is connected to the inlet of the heat source channel of the first heat exchanger 110 through a condensate delivery pipe; a condensate delivery pump 160 is provided on the condensate delivery pipe.

[0047] A condensate delivery pump 160 is provided on the condensate delivery pipe to provide power for delivering the condensate. Optionally, the condensate delivery pump 160 is a centrifugal pump.

[0048] Optionally, the deamination system 100 further includes a weight removal system 170 , and an inlet of the weight removal system 170 is in communication with an outlet of the heat source channel of the second heat exchanger 120 .

[0049] The function of the weight removal system 170 is to use a filter element to intercept heavy metals in the wastewater after deammonification. It should be noted that the weight removal system 170 belongs to the existing technology and its structure refers to a precision filter, so it will not be described in detail here.

[0050] Optionally, the deamination system 100 further includes a distilled water system 180 , and an inlet of the distilled water system 180 is in communication with an outlet of the heat source channel of the first heat exchanger 110 .

[0051] After cooling in first heat exchanger 110, the condensed water enters distilled water system 180. Distilled water system 180 processes the steam condensed water produced by the MVR through membrane treatment until it meets standards for reuse. It should be noted that distilled water system 180 is conventional technology, and its structure is similar to that of a reverse osmosis device, so detailed description is omitted here.

[0052] Optionally, the first heat exchanger 110 and / or the second heat exchanger 120 is a plate heat exchanger.

[0053] Optionally, the deammonification system 100 includes an ammonia-containing stock liquid tank 190, which is connected to the inlet of the cold source channel of the first heat exchanger 110. The ammonia-containing stock liquid is stored in the ammonia-containing stock liquid tank 190. During operation, the ammonia-containing stock liquid is discharged from the ammonia-containing stock liquid tank 190 and enters the first heat exchanger 110.

[0054] Optionally, the ammonia-containing raw liquid tank 190 and the first heat exchanger 110 are connected via a raw liquid delivery pipeline, and a raw liquid delivery pump 191 is provided on the raw liquid delivery pipeline.

[0055] A raw liquid delivery pump 191 is provided on the raw liquid delivery pipeline to provide power for delivering the ammonia-containing raw liquid. Optionally, the raw liquid delivery pump 191 is a centrifugal pump.

[0056] In summary, the deamination system 100 provided by the embodiment of the present invention, due to the first heat exchanger 110 and the second heat exchanger 120, and their associated configuration with the reboiler 140 and the deamination tower 130, can recover and utilize the heat in the steam condensate and the deamination liquid, thereby saving energy consumption of the entire system and reducing processing costs. This effectively improves the problem of insufficient utilization of the heat energy of the steam condensate.

[0057] In a preferred embodiment, the steam condensate from the MVR (forced circulation evaporator, falling film evaporator) is collected for secondary use to preheat the steam before entering the deamination tower, thereby reducing steam consumption.

[0058] The present invention also provides a ternary wastewater mother liquor treatment system, which includes the deammoniation system 100 provided by the present invention. Since the ternary wastewater mother liquor treatment system includes the deammoniation system 100 provided by the present invention, it has the characteristic of low energy consumption.

[0059] The above is only a specific implementation method of the present invention, but the protection scope of the present invention is not limited to this. Any changes or replacements that can be easily thought of by any technician familiar with this technical field within the technical scope disclosed in the present invention should be covered by the protection scope of the present invention.

Claims

1. A deamination system, characterized in that: It includes a first heat exchanger, a second heat exchanger, a deamination tower, a tail gas absorption tower and a reboiler; The outlet of the cold source channel of the first heat exchanger is connected to the inlet of the cold source channel of the second heat exchanger, the outlet of the cold source channel of the second heat exchanger is connected to the feed inlet of the deamination tower, the gas outlet of the deamination tower is connected to the tail gas absorption tower, the middle part of the deamination tower has a high-temperature liquid inlet, and the bottom part has a raw liquid outlet, the raw liquid outlet is connected to the inlet of the cold source channel of the reboiler, and the outlet of the cold source channel of the reboiler is connected to the high-temperature liquid inlet; The bottom of the reboiler is provided with a deammonification liquid discharge outlet, which is connected to the inlet of the heat source channel of the second heat exchanger; the inlet of the heat source channel of the reboiler is connected to the high-temperature steam inlet pipe, and the outlet of the heat source channel of the reboiler is connected to the inlet of the cold source channel of the first heat exchanger.

2. The deamination system according to claim 1, characterized in that: The deamination system further comprises a steam condensate collecting device, and the steam condensate discharge port of the reboiler is connected to the inlet of the steam condensate collecting device; The deammonification system further includes a falling film evaporator condensate inlet pipe and a forced circulation evaporator steam condensate inlet pipe, and the falling film evaporator condensate inlet pipe and the forced circulation evaporator steam condensate inlet pipe are connected to the inlet of the steam condensate collecting device.

3. The deamination system according to claim 2, characterized in that: The outlet of the steam condensate collecting device is connected to the inlet of the heat source channel of the first heat exchanger through a condensate delivery pipe; The condensate delivery pipeline is provided with a condensate delivery pump.

4. The deamination system according to claim 1, characterized in that: The deammoniation system further includes a weight removal system, the inlet of which is in communication with the outlet of the heat source channel of the second heat exchanger.

5. The deamination system according to claim 1, characterized in that: The deammoniation system further includes a distilled water system, the inlet of the distilled water system being in communication with the outlet of the heat source channel of the first heat exchanger.

6. The deamination system according to claim 1, characterized in that: The first heat exchanger and / or the second heat exchanger is a plate heat exchanger.

7. The deamination system according to claim 1, characterized in that: The deammonification system includes an ammonia-containing raw liquid tank, which is connected to the inlet of the cold source channel of the first heat exchanger.

8. The deamination system according to claim 7, characterized in that: The ammonia-containing raw liquid tank and the first heat exchanger are communicated with each other through a raw liquid delivery pipeline, and a raw liquid delivery pump is provided on the raw liquid delivery pipeline.

9. The ternary wastewater mother liquor treatment system is characterized by: The invention comprises a deamination system as described in any one of claims 1 to 8.

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