CN108726612A

CN108726612A - The processing method of ammonium salt-containing waste water

Info

Publication number: CN108726612A
Application number: CN201710266201.XA
Authority: CN
Inventors: 殷喜平; 李叶; 顾松园; 刘志坚; 王涛; 陈玉华; 安涛; 周岩; 苑志伟; 伊红亮
Original assignee: China Petroleum and Chemical Corp; Sinopec Catalyst Co
Current assignee: China Petroleum and Chemical Corp; Sinopec Catalyst Co
Priority date: 2017-04-21
Filing date: 2017-04-21
Publication date: 2018-11-02
Anticipated expiration: 2037-04-21
Also published as: CN108726612B

Abstract

The present invention relates to sewage treatment fields, disclose a kind of processing method of ammonium salt-containing waste water, which contains NH₄ ⁺、SO₄ ^2‑、Cl^‑And Na⁺, which is characterized in that this approach includes the following steps, and 1) by the first evaporation of pending waste water progress, the first concentrate of the first steam containing ammonia and sodium chloride-containing crystal is obtained, the pending waste water contains the ammonium salt-containing waste water；2) the first concentrate of the sodium chloride-containing crystal is subjected to low-temperature treatment, obtains the treatment fluid of sodium chloride-containing crystal；3) treatment fluid of the sodium chloride-containing crystal is carried out first to be separated by solid-liquid separation, and first is separated by solid-liquid separation obtained liquid phase and carries out the second evaporation, obtain the second concentrate of the second steam containing ammonia and sulfur acid sodium crystal；4) the second concentrate of the sulfur acid sodium crystal second is carried out to be separated by solid-liquid separation.Ammonium and sodium sulphate, sodium chloride in waste water can be separately recovered in this method, farthest recycle the resource in waste water.

Description

The processing method of ammonium salt-containing waste water

Technical field

The present invention relates to sewage treatment fields, and in particular, to a kind of processing method of ammonium salt-containing waste water, more particularly to One kind containing NH₄ ⁺、SO₄ ^2-、Cl^-And Na⁺Ammonium salt-containing waste water processing method.

Background technology

In the production process of oil refining catalyst, a large amount of sodium hydroxide, hydrochloric acid, sulfuric acid, ammonium salt, sulfate, salt are needed The inorganic acids alkali salt such as hydrochlorate generates and largely contains ammonium, sodium chloride and sodium sulphate and alumino-silicate combined sewage.For such Sewage, common practice is first in the range of adjusting pH value to 6~9, after removing most suspended substances, then to adopt in the prior art The removing of ammonium ion is carried out with biochemical process, blow-off method or vaporizing extract process, then, by saline sewage through overregulating pH value, the big portion of removing Divide suspended matter, remove hardness, except silicon and partial organic substances and then by ozone biological activated carbon adsorption and oxidation or other advanced oxygen Change method oxidation removal major part organic matter, then, after further removing hardness into ion interchange unit, into thickening device After (such as reverse osmosis and/or electrodialysis) concentration, then using MVR evaporative crystallizations or multiple-effect evaporation crystallization, obtain the chlorine containing a small amount of ammonium salt Change sodium and sodium sulphate mixing carnallite；Either；First adjust pH value in the range of 6.5~7.5, removing most suspended substances, so Afterwards, it removes hardness, remove silicon and partial organic substances, gone using ozone biological activated carbon adsorption and oxidation or the oxidation of other advanced oxidation processes It is (such as reverse osmosis and/or electric into thickening device after further removing hardness into ion interchange unit after most of organic matter Dialysis) after concentration, then crystallized using MVR evaporative crystallizations or multiple-effect evaporation, sodium chloride and the sodium sulphate mixing for obtaining ammonium salt-containing are miscellaneous Salt.But these carnallites containing ammonium are difficult to handle at present, or the processing cost is high, also, the process of removing early period ammonium ion, Add additional the processing cost of waste water.

In addition, biochemical process deamination can only handle the waste water of low ammonium content, and due to COD contents deficiency in Catalyst sewage Biochemical treatment cannot be directly carried out, machine object, such as glucose or starch are also additionally supplemented with during biochemical treatment, just may be used To handle ammoniacal nitrogen using biochemical process.Sixty-four dollar question is biochemical process deamination treated waste water often total nitrogen (nitre not up to standard Acid ion, nitrite ion content are exceeded), it is also necessary to advanced treating, in addition the content of salt does not reduce (20g/ in waste water L~30g/L), it is unable to direct emission, needs further to carry out desalting processing.

Air- extraction deamination needs to add a large amount of adjusting PH with base value, alkaline consumption is very high, due to de- to deviate from the ammoniacal nitrogen in waste water The alkali in waste water after ammonia cannot recycle, and treated, and pH value of waste water is very high, and the processing cost is high, and air lift rear catalyst is dirty The not big variation of COD contents in water, the salt content in waste water do not reduce (20g/L~30g/L), are unable to direct emission, It needs further to carry out desalting processing, wastewater treatment operating cost is high, remains a large amount of alkali in treated waste water, pH value is very Height, waste is big, and processing cost is up to 50 yuan/ton.

Invention content

The purpose of the present invention is overcome to contain NH in the prior art₄ ⁺、SO₄ ^2-、Cl^-And Na⁺Ammonium salt-containing cost for wastewater treatment Height, and the problem of can only obtain mixing salt crystal provides and a kind of at low cost and environmentally friendly contains NH₄ ⁺、SO₄ ^2-、Cl^-And Na⁺'s Wastewater treatment method, this method can be separately recovered ammonium and sodium chloride, sodium sulphate in waste water, farthest recycle waste water In resource.

To achieve the goals above, the present invention provides a kind of processing method of ammonium salt-containing waste water, which contains NH₄ ⁺、SO₄ ^2-、Cl^-And Na⁺, this approach includes the following steps,

1) pending waste water is subjected to the first evaporation, obtains the first concentration of the first steam containing ammonia and sodium chloride-containing crystal Liquid, the pending waste water contain the ammonium salt-containing waste water；

2) the first concentrate of the sodium chloride-containing crystal is subjected to low-temperature treatment, obtains the treatment fluid of sodium chloride-containing crystal；

3) treatment fluid of the sodium chloride-containing crystal is carried out first to be separated by solid-liquid separation, and obtained liquid is separated by solid-liquid separation by first The second evaporation is mutually carried out, the second concentrate of the second steam containing ammonia and sulfur acid sodium crystal is obtained；

4) the second concentrate of the sulfur acid sodium crystal second is carried out to be separated by solid-liquid separation；

Wherein, before the pending waste water is carried out the first evaporation, the pH value for adjusting the pending waste water is more than 9；Second evaporation makes sodium chloride crystal not crystallize precipitation；Relative to the SO contained in 1 mole of pending waste water₄ ^2-, institute State the Cl contained in pending waste water^-It is 7.15 moles or more.

Through the above technical solutions, for NH is contained₄ ⁺、SO₄ ^2-、Cl^-And Na⁺Waste water, by advance by pending waste water After pH value is adjusted to specific range, the first vaporising device is recycled to be evaporated isolated sodium chloride-containing crystal or sulfur acid Then the concentrate of sodium crystal and sodium chloride crystal and compared with concentrated ammonia liquor recycles low-temperature treatment to make the molten of sodium sulphate in concentrate Solution, sodium chloride further crystallize precipitation, obtain sodium chloride crystal, and the second vaporising device is then recycled to be evaporated to obtain again The concentrate of sulfur acid sodium crystal and compared with weak aqua ammonia, obtains sulfate crystal.This method can respectively obtain the chlorination of high-purity Sodium and sodium sulphate, the difficulty during avoiding mixed salt processing and recycling, are completed at the same time separation of ammonia and the process of salt, and adopt So that waste water is heated up simultaneously with heat exchange method and steam containing ammonia condenses, the reasonable heat using in evaporation process, energy saving, drop Low cost for wastewater treatment, the ammonium in waste water are recycled in the form of ammonium hydroxide, and sodium sulphate and sodium chloride are recycled with crystal form respectively, whole A process does not have waste residue and liquid generation, realizes the purpose to turn waste into wealth.

Further, this method is matched by the first evaporation and low-temperature treatment so that the first evaporation can be in higher temperatures Degree is lower to carry out, and improves the solid content and evaporation efficiency in the first evaporation concentrated solution, can be simultaneously reached energy-saving effect.

Other features and advantages of the present invention will be described in detail in subsequent specific embodiment part.

Description of the drawings

Attached drawing is to be used to provide further understanding of the present invention, an and part for constitution instruction, with following tool Body embodiment is used to explain the present invention together, but is not construed as limiting the invention.In the accompanying drawings：

Fig. 1 is a kind of flow diagram of the ammonium salt-containing wastewater treatment method of embodiment provided by the invention.

Fig. 2 is the flow diagram of the ammonium salt-containing wastewater treatment method of another embodiment provided by the invention.

Reference sign

1, the second vaporising device 72, second circulation pump

2, the first vaporising device 73, third circulating pump

22, low-temperature treatment tank 74, the 4th circulating pump

31, the first heat-exchanger rig 76, the 6th circulating pump

32, the second heat-exchanger rig 77, the 7th circulating pump

33, third heat-exchanger rig 78, the 8th circulating pump

34, the 4th heat-exchanger rig 79, the 9th circulating pump

35, the 5th heat-exchanger rig 80, the tenth circulating pump

36, the 6th heat-exchanger rig 81, vacuum pump

51, the first tank used for storing ammonia 82, circulating water pool

52, the second tank used for storing ammonia 83, tail gas absorber

53, the first mother liquor tank 91, the first equipment for separating liquid from solid

54, the second mother liquor tank 92, the second equipment for separating liquid from solid

61, the first pH value measuring device 101, the first compressor

62, the second pH value measuring device 102, the second compressor

71, first circulation pumps

Specific implementation mode

The specific implementation mode of the present invention is described in detail below.It should be understood that described herein specific Embodiment is merely to illustrate and explain the present invention, and is not intended to restrict the invention.

The endpoint of disclosed range and any value are not limited to the accurate range or value herein, these ranges or Value should be understood as comprising the value close to these ranges or value.For numberical range, between the endpoint value of each range, respectively It can be combined with each other between the endpoint value of a range and individual point value, and individually between point value and obtain one or more New numberical range, these numberical ranges should be considered as specific open herein.

Below in conjunction with Fig. 1-2, the present invention will be described, and the present invention is not limited by Fig. 1-2.

The processing method of ammonium salt-containing waste water provided by the invention, the ammonium salt-containing waste water contain NH₄ ⁺、SO₄ ^2-、Cl^-And Na⁺, should Method includes the following steps,

2) the first concentrate of the sodium chloride-containing crystal is subjected to low-temperature treatment, obtains the processing of sodium chloride-containing crystal Liquid；

Preferably, the pending waste water is the ammonium salt-containing waste water；Alternatively, the pending waste water contains and described contains ammonium Salt waste water and described second is separated by solid-liquid separation obtained liquid phase.

It is highly preferred that the pending waste water is the ammonium salt-containing waste water is separated by solid-liquid separation obtained liquid phase with described second At least part of mixed liquor.

It is further preferred that the pending waste water is the ammonium salt-containing waste water is separated by solid-liquid separation obtained liquid with described second The mixed liquor of phase.

Preferably, before the pending waste water is carried out the first evaporation, the pH value for adjusting the pending waste water is big In 10.8.In addition, for the pending waste water pH value the upper limit there is no limit, such as can be 14 hereinafter, preferably 13.5 hereinafter, more preferable 13 or less.

Method provided by the invention, which can be directed to, contains NH₄ ⁺、SO₄ ^2-、Cl^-And Na⁺Ammonium salt-containing waste water handled, remove Contain NH₄ ⁺、SO₄ ^2-、Cl^-And Na⁺Outside, to the ammonium salt-containing waste water, there is no particular limitation.From the treatment effeciency for improving waste water From the point of view of, relative to the SO contained in 1 mole of pending waste water₄ ^2-, the Cl that contains in the pending waste water^-For 7.15 moles or more, preferably 9.5 moles or more, preferably 10 moles or more, preferably 50 moles are hereinafter, more preferably 40 rub You hereinafter, further preferably 30 moles hereinafter, for example can be 8-20 moles, preferably 8-12 moles, more preferably 10-12 Mole.By by SO₄ ^2-And Cl^-Molar ratio control in above range, sodium chloride can be made to be precipitated and sodium sulphate in low-temperature treatment It is completely dissolved, to achieve the purpose that efficiently separate sodium chloride.It, in the present invention can also will be in addition, as above described below Thus the second Recycling Mother Solution obtained in second evaporation process is come to the first evaporation to the SO in pending waste water₄ ^2-And Cl^- Molar ratio be adjusted, and the balance of sodium hydroxide can be maintained.

In the present invention, first evaporation makes sodium chloride crystal be precipitated, and considers in terms of raising treatment effeciency, excellent It selects first evaporation that sodium chloride crystal and sodium sulfate crystal is made to be precipitated, obtains the of sulfur acid sodium crystal and sodium chloride crystal One concentrate.In the case where obtaining the first concentrate of sulfur acid sodium crystal and sodium chloride crystal, first evaporation needs Sodium sulfate crystal is set to be dissolved in low-temperature treatment, specifically, obtaining sulfur acid sodium crystal and sodium chloride crystalline substance in the first evaporation First concentrate of body need to ensure that sodium sulfate crystal therein can be completely dissolved in low-temperature treatment.By controlling described the One evaporation evaporation capacity, make sodium sulphate, sodium chloride simultaneously crystallize precipitation (i.e. first evaporate obtain sulfur acid sodium crystal and sodium chloride First concentrate of crystal), then made in the first concentrate of sulfur acid sodium crystal and sodium chloride crystal by the low-temperature treatment Sodium sulfate crystal dissolving, sodium chloride further crystallizes precipitation, obtains the treatment fluid for containing only sodium chloride crystal.

Treatment fluid about the sodium chloride-containing crystal, it is not excluded that the sulfuric acid of sodium chloride crystallization entrainment or adsorption Sodium.Since the water content of crystal after separation of solid and liquid is different, the content of sodium sulphate is in 8 mass % in the sodium chloride crystal generally yielded (preferably 4 mass %) below, in the present invention, when the content of sodium sulphate is below 8 mass % in obtained sodium chloride crystal It can think that sodium sulphate has dissolved.

In the present invention, second evaporation makes sodium chloride not crystallize precipitation, refers to that the sodium chloride of control mixed system is dense Degree is no more than the solubility under the second evaporation conditions (including but not limited to temperature, pH value etc.), it is not excluded that sulfate crystal presss from both sides The sodium chloride of band or adsorption.Since the water content of crystal after separation of solid and liquid is different, chlorine in the sodium sulfate crystal generally yielded Change the content of sodium below 8 mass % (preferably 4 mass %), in the present invention, sodium chloride in obtained sodium sulfate crystal It can think that sodium chloride does not crystallize precipitation when content is below 8 mass %.

In the present invention, it is to be understood that first steam containing ammonia and second steam containing ammonia are this field So-called indirect steam.The pressure is the pressure in terms of gauge pressure.

According to the present invention, there is no particular limitation for the mode that first evaporation and second evaporation carry out, and reaches The purpose evaporated under corresponding evaporation conditions can be used for example various vaporising devices commonly used in the art and carry out.Tool Body can be one or more in MVR vaporising devices, multi-effect evaporating device and single-effect evaporating equipment.Wherein, described first steams Hair is preferably carried out by MVR vaporising devices；Second evaporation is preferably carried out by MVR vaporising devices.

As MVR vaporising devices, such as can be selected from MVR falling film evaporators, MVR forced-circulation evaporators, MVR-FC It is one or more in continuous crystallisation evaporator, MVR-OSLO continuous crystallisation evaporators.Wherein, preferably MVR forced circulations are steamed Send out device, MVR-FC continuous crystallisation evaporators, more preferably falling liquid film+forced circulation two-stage MVR crystallizing evaporators.

As each effect evaporator in single-effect evaporating equipment or multi-effect evaporating device, such as falling film type evaporation can be selected from It is device, film-rising evaporator, scraper-type evaporator, evaporator with central downcomer, basket evaporator, external heating type evaporator, strong It is one or more in circulating evaporator and Liewen evaporator processed.Wherein, preferably forced-circulation evaporator, external-heat evaporation Device.Above-mentioned evaporator is formed by heating room and vaporization chamber respectively, can also include other evaporation accessories as needed, such as The demister for making liquid foam further detach, the vacuum plant when condenser and decompression operation that make indirect steam all condense Deng.When the vaporising device is multi-effect evaporating device, wherein there is no particular limitation for the evaporator quantity contained, it can be according to need The evaporation conditions selection wanted can be 2 effects or more, preferably 2-5 effects, more preferably 2-4 effects.

In the present invention, when carrying out first evaporation and/or the second evaporation using multi-effect evaporating device, liquid to be evaporated Feeding manner can be identical or different, fair current commonly used in the art, adverse current or advection mode may be used.It is described suitable Stream is specially：Liquid to be evaporated is passed through to each effect evaporator of multi-effect evaporating device successively, before the multi-effect evaporating device The steam containing ammonia that 1st effective evaporator evaporates is passed through in rear 1st effective evaporator.The adverse current is specially：By liquid to be evaporated according to The secondary each effect evaporator for being passed through multi-effect evaporating device contains ammonia by what the rear 1st effective evaporator of the multi-effect evaporating device evaporated Before steam is passed through in 1st effective evaporator.The advection is specially：Liquid to be evaporated is individually passed through to each effect of multi-effect evaporating device The steam containing ammonia that the preceding 1st effective evaporator of the multi-effect evaporating device evaporates is passed through in rear 1st effective evaporator by evaporator. Wherein, it is preferred to use forward feed mode.When using fair current or adverse current feeding, the condition of evaporation refers to multi-effect evaporating device most The evaporation conditions of 1st effective evaporator afterwards；When being fed using advection, the condition of evaporation refers to each effect evaporation of multi-effect evaporating device The evaporation conditions of device.

It in the present invention, can be in order to which the pending waste water to be passed through to each effect evaporator of multi-effect evaporating device successively Circulating pump is set between each effect evaporator, the waste water after the evaporation of preceding 1st effective evaporator is passed through next effect by the circulating pump Evaporator.

In the present invention, the circulating pump between selected each effect evaporator can be various forms commonly used in the art Pump, generate a large amount of fine grain cores to make material be uniformly evaporated, avoid, prevent crystal grain and impeller high velocity impact in cycle magma Generate a large amount of secondary nucleus, the circulating pump is preferably the centrifugal pump of the slow-speed of revolution, more preferably big flow, the slow-speed of revolution guide pump Wheel or big flow, low lift, the slow-speed of revolution axial-flow pump.

In the present invention, the condition of first evaporation can be selected suitably as needed, and reaching makes in the treatment fluid There is no the purposes of sodium sulfate crystal.It is described first evaporation condition may include：Temperature be 35 DEG C or more, pressure be- 95kPa or more.In order to improve evaporation efficiency, it is preferable that it is described first evaporation condition include：Temperature is 45 DEG C~175 DEG C, pressure Power is -95kPa~18110kPa；Preferably, the condition of first evaporation includes：Temperature be 60 DEG C~175 DEG C, pressure be- 87kPa~18110kPa；Preferably, the condition of first evaporation includes：Temperature is 75 DEG C~175 DEG C, and pressure is -73kPa ~653kPa；Preferably, the condition of first evaporation includes：Temperature be 80 DEG C~130 DEG C, pressure be -66kPa~ 117kPa；Preferably, the condition of first evaporation includes：Temperature is 95 DEG C~110 DEG C, and pressure is -37kPa~12kPa；It is excellent Selection of land, it is described first evaporation condition include：Temperature is 100 DEG C~110 DEG C, and pressure is -23kPa~12kPa.

In the present invention, the operating pressure of the first evaporation is preferably the saturated vapor pressure of evaporated feed liquid.

In the present invention, the flow of the first evaporation can suitably be selected according to the ability that equipment is handled, such as can be 0.1m³/ h or more (such as 0.1m³/ h~500m³/h)。

By making the first evaporation carry out under these conditions, the efficiency of evaporation can be improved, energy consumption is reduced.Ensureing maximum While evaporation capacity (cycles of concentration), ensure the first concentrate sulfate crystal fully dissolved after low-temperature treatment, to The purity for the sodium chloride crystal that can ensure.

It can be evaporated in the pending waste water according to the present invention by controlling the evaporation conditions of the first vaporising device 2 The 90 mass % or more (preferably 95 mass % or more) of contained ammonia, to obtain higher first ammonium hydroxide of concentration, the first ammonium hydroxide Can with direct reuse in the production process of catalyst, either with acid neutralization obtain carrying out after ammonium salt reuse or to water and corresponding Ammonium salt or ammonium hydroxide allotment use.

According to the present invention, first evaporation makes the sodium chloride in pending waste water crystallize precipitation, it is preferable that pending Sodium chloride and sodium sulphate in waste water crystallize precipitation simultaneously, by obtaining the higher sodium chloride-containing crystal of purity after low-temperature treatment Treatment fluid.Preferably, it is described first evaporation make sodium sulphate in the treatment fluid a concentration of Y or less (preferably 0.9Y-0.99Y, Preferably 0.95Y-0.98Y), wherein Y is under conditions of low-temperature treatment, and sodium chloride and sodium sulphate reach full in treatment fluid With when sodium sulphate concentration.By the way that the extent control of the first evaporation within the above range, can ensured that low-temperature treatment can be with It is precipitated sodium chloride crystallization as much as possible under conditions of so that sodium sulphate is dissolved.By making sodium chloride knot in the first evaporation as possible Crystalline substance can improve waste water treatment efficiency, reduce energy waste.

In the present invention, the carry out degree of first evaporation obtains liquid by the evaporation capacity of the first evaporation of monitoring The mode of amount carries out, and specifically, cycles of concentration is controlled by the evaporation capacity i.e. amount of the first ammonium hydroxide of the first evaporation of control, makes the The sulfate crystal being precipitated in one evaporation concentrated solution can be dissolved in low-temperature treatment.Here the first degree being concentrated by evaporation is led to The mode for crossing measurement evaporation capacity is monitored, and specifically can carry out flow measurement with use quality flowmeter.

A preferred embodiment according to the present invention will before the pending waste water is carried out the first evaporation First steam containing ammonia or the first ammonium hydroxide (the first liquid of steam condensation containing ammonia) carry out the first heat exchange with the pending waste water. There is no particular limitation for the mode of first heat exchange, and the heat exchange mode that this field routine may be used carries out.Described first The number of heat exchange can be preferably 2-4 times, more preferably 2-3 times more than primary.It is defeated after first heat exchange The ammonium hydroxide gone out is cooled, and heat utmostly recycles inside processing unit, and the energy is rationally utilized, and reduces waste.

A preferred embodiment according to the present invention, as shown in Figure 1, first heat exchange is filled by the first heat exchange It sets the 31, the 5th heat-exchanger rig 35 and the second heat-exchanger rig 32 carries out, specifically, will be evaporated in first vaporising device 2 To the first steam containing ammonia pass sequentially through the second heat-exchanger rig 32 and the first heat-exchanger rig 31, it is dense by the first of sodium chloride-containing crystal Contracting liquid first passes through the first heat-exchanger rig 31 or the 5th heat-exchanger rig by the 5th heat-exchanger rig 35, while by the pending waste water After 35 carry out the first heat exchange, then pass through the first heat exchange of progress of the second heat-exchanger rig 32.By first heat exchange, make institute It states the heating of pending waste water to be convenient for evaporating, while first steam containing ammonia being made to condense to obtain the first ammonium hydroxide, described first Ammonium hydroxide can be stored in the first tank used for storing ammonia 51.

In the present invention, do not have for first heat-exchanger rig 31, the 5th heat-exchanger rig 35 and the second heat-exchanger rig 32 It is special to limit, various heat exchangers commonly used in the art can be used, reaches first steam containing ammonia and waits locating with described Reason waste water carries out the purpose of first heat exchange.Specifically, it can be jacketed type exchanger, plate heat exchanger, shell Formula heat exchanger etc., wherein preferably plate heat exchanger.The material of the heat exchanger can be specifically chosen as needed, such as in order to Resist chloride ion corrosion, material can be selected for two phase stainless steel, the heat exchanger of titanium or titanium alloy, Hastelloy, temperature compared with The heat exchanger containing plastic material can be selected when low.

According to the present invention, in order to make full use of the thermal energy of the first steam containing ammonia, preferably by the first heat exchange after, it is described to wait for Handle waste water temperature be 52 DEG C~182 DEG C, more preferably 67 DEG C~182 DEG C, further preferably 87 DEG C~137 DEG C, more into One step is preferably 102 DEG C~117 DEG C.

In the present invention, for the method for pH value adjusting, there is no particular limitation, such as can use additional basic species The mode of matter adjusts the pH value of the pending waste water.There is no particular limitation for the alkaline matter, reaches above-mentioned adjusting pH value Purpose.In order not to introduce new impurity in pending waste water, the purity of gained crystal is improved, the basic species are of fine quality It is selected as NaOH.

Feed postition as the alkaline matter is the feed postition of this field routine, but preferably makes alkaline matter It is mixed in form of an aqueous solutions with the pending waste water, such as the aqueous solution containing alkaline matter can be passed into and import institute It states and is mixed in the pipeline of pending waste water.For the content of alkaline matter in aqueous solution, there is no particular limitation, as long as It can achieve the purpose that above-mentioned adjusting pH value.But it in order to reduce the dosage of water, further reduces the cost, it is preferable to use alkalinity The saturated aqueous solution of substance.In order to monitor the pH value of the pending waste water, can be waited for described in measurement after above-mentioned adjusting pH value Handle the pH value of waste water.

A preferred embodiment according to the present invention, as shown in Figure 1, first evaporation process is in the first evaporation dress It is carried out in setting 2, the pending waste water is being sent into the first heat-exchanger rig 31 or the first heat exchange of progress of the 5th heat-exchanger rig 35 Before, by the way that the pending waste water is being sent into the aqueous solution containing alkaline matter of importing in the pipeline of heat-exchanger rig simultaneously Mixing, to carry out first time pH value adjusting；Then the pending waste water is sent into the first heat-exchanger rig 31 or the 5th heat exchange dress 35 the first heat exchanges of carry out are set, are next sent into the pipeline of the second heat-exchanger rig 32 described in importing by the pending waste water Aqueous solution containing alkaline matter and mixing, to carry out second of pH value adjusting.It is adjusted, is made described pending by pH value twice PH value of the waste water before carrying out the first evaporation is more than 9, preferably greater than 10.8.Preferably, first time pH value adjusting makes The pH value for obtaining pending waste water is more than 7 (preferably 7-9), and second of pH value adjusts so that pH value (is preferably greater than more than 9 10.8).In accordance with the present invention it is preferred that before carrying out first heat exchange, the pH value for adjusting the pending waste water is more than 7。

In order to detect above-mentioned first time pH value adjust and second of pH value adjust after pH value, preferably will be described pending Waste water, which is sent on the pipeline of the first heat-exchanger rig 31 and the 5th heat-exchanger rig 35, is arranged the first pH value measuring device 61 to measure the The second pH value is being arranged the pending waste water to be sent on the pipeline of the second heat-exchanger rig 32 in pH value after pH value adjusting Measuring device 62 measures the pH value after second pH value is adjusted.

In the present invention, the first heat exchange, adjust the pH value of the pending waste water and the tune of the pending waste water With process (the pending waste water contains in the case that the ammonium salt-containing waste water is separated by solid-liquid separation obtained liquid phase with described second, Needing to carry out the allocation process of the pending waste water) there is no particular limitation for the priority that carries out, and it is appropriate to carry out as needed Selection, completed before the pending waste water is carried out the first evaporation.

In the present invention, the first concentrate of the sodium chloride-containing crystal is subjected to low-temperature treatment, keeps sodium sulfate crystal molten Solution, obtains the treatment fluid of sodium chloride-containing crystal.By controlling the evaporation capacity of first evaporation, make sodium sulphate in the treatment fluid A concentration of Y hereinafter, can make in low-temperature process, sodium sulfate crystal can be completely dissolved.

According to the present invention, there is no particular limitation for the mode that the low-temperature treatment carries out, as long as reaching control temperature appropriate Spend the sodium sulfate crystal dissolving in the first concentrate of the sodium chloride-containing crystal for making the first evaporation obtain.According to the present invention, The temperature of the low-temperature treatment is less than the temperature of the first evaporation, and specifically, the condition of the low-temperature treatment may include：Temperature is 13 DEG C~100 DEG C, preferably 15 DEG C~45 DEG C, more preferably 15 DEG C~35 DEG C, further preferably 17.9 DEG C~35 DEG C；Such as Can be 18 DEG C, 19 DEG C, 20 DEG C, 21 DEG C, 22 DEG C, 23 DEG C, 24 DEG C, 25 DEG C, 26 DEG C, 27 DEG C, 28 DEG C, 29 DEG C, 30 DEG C, 31 DEG C, 32℃、33℃、34℃、35℃、36℃、37℃、38℃、39℃、40℃、41℃、42℃、43℃、44℃、45℃、46℃、47 DEG C, 48 DEG C, 49 DEG C, 50 DEG C, 55 DEG C and 60 DEG C.In order to ensure that the effect of low-temperature treatment, the residence time of low-temperature treatment can be 10min~600min, preferably 20min~300min, preferably 50min~70min.

In the present invention, pass through the condition of first evaporation and low-temperature treatment of control so that the first evaporation can be higher Evaporating temperature, closer to normal pressure evaporating pressure under carry out, avoid at a lower temperature evaporation when the low problem of efficiency, not only Evaporation efficiency is improved, and the energy consumption of evaporation process can be reduced, improves wastewater treatment speed.On this basis, low temperature The temperature control of processing is easier, and low-temperature treatment temperature can be under conditions of less than evaporating temperature (such as 45 DEG C or less) It is operated, is more conducive to the dissolving of sodium sulphate and the precipitation of sodium chloride.

In the present invention, the low-temperature treatment may be used various cooling systems commonly used in the art and carry out, such as It can select low-temperature treatment tank 22.Preferably, it can be provided with cooling-part in the low-temperature treatment tank 22, can is specifically Import the component of cooling water.By the cooling-part, the first concentrate in low-temperature treatment tank can be cooled down rapidly.It is preferred that Ground can be provided with mixing component in the low-temperature treatment tank 22, by the mixing component, can make in the first concentrate Solid-liquid distributed mutually, Temperature Distribution are uniform, and reaching makes sodium sulfate crystal fully dissolve, and the mesh that sodium chloride crystal is precipitated to greatest extent 's.

In the present invention, the treatment fluid of the sodium chloride-containing crystal by first be separated by solid-liquid separation after obtain sodium chloride crystal and First mother liquor (i.e. first is separated by solid-liquid separation obtained liquid phase).There is no particular limitation for described first method being separated by solid-liquid separation, such as It can be selected from one or more in centrifugation, filtering, sedimentation.

According to the present invention, the separation of solid and liquid of first concentrate may be used the first equipment for separating liquid from solid (be, for example, from Scheming, band filter, flame filter press etc.) 91 progress.After the separation of solid and liquid, the first equipment for separating liquid from solid 91 obtain One mother liquor is temporarily stored into the first mother liquor tank 53, and can be sent into the second vaporising device 1 by the 6th circulating pump 76 and be carried out the second steaming Hair.In addition, the impurity such as certain chlorion, free ammonia, hydroxide ion can be adsorbed by being difficult to avoid that on obtained sodium chloride crystal, In order to remove the impurity of absorption, the peculiar smell of solid salt is reduced, corrosivity is reduced, improves the purity of the crystal, it is preferable that described Sodium chloride crystal water, the ammonium salt-containing waste water or sodium chloride solution carry out the first washing and drying.In order to avoid washing process The dissolving of middle sodium chloride crystal, it is preferable that the sodium chloride crystal is washed with sodium-chloride water solution.It is highly preferred that described Sodium chloride and sodium sulphate reach full simultaneously at the concentration of the sodium-chloride water solution preferably temperature corresponding to sodium chloride crystal to be washed The concentration of sodium chloride in the aqueous solution of sum.

It is separated by solid-liquid separation the mode washed with first as above-mentioned first, there is no particular limitation, and ability can be used for example The elutriation apparatus and solid-liquid separating equipment of domain routine, which combine, to carry out, can also be in the equipment for separating liquid from solid such as band filter of segmentation Upper progress.Preferably, first washing includes eluriating and/or eluting.For above-mentioned elutriation and elution, there is no particular limitation, It can be carried out by the method for this field routine.It is described elutriation and elution number there is no particular limitation, can be 1 time with On, the sodium chloride crystal of higher purity, preferably 2-4 times in order to obtain.During elutriation, use the ammonium salt-containing waste water as wash in a pan It does not recycle generally when washing lotion, can be used with circulated in countercurrent when doing elutriation liquid using the cleaning solution of the first washing recycling.It carries out Before the elutriation, tentatively separation of solid and liquid is carried out preferably by way of sedimentation and obtains the slurries (content liquid of sodium chloride-containing crystal For 35 mass % or less).During elutriation, relative to the slurries of 1 parts by weight sodium chloride-containing crystal, the liquid used is eluriated For 1-20 parts by weight.It is preferable to use sodium-chloride water solution progress for elution.In order to further increase the effect of elutriation, purity is obtained more High sodium chloride crystal, in the case of preferred, the liquid that elution can be used to obtain is washed, it is preferable to use water or sodium chloride Solution.For the liquid that washing generates, before second of the pH value preferably returned it to before the evaporation of the first vaporising device is adjusted, Such as after being returned by the 8th circulating pump 78 and being mixed with pending waste water before second pH is adjusted, by second of pH adjusting and the After the heat exchange of two heat-exchanger rigs 32, the evaporation of the first vaporising device is returned.

A preferred embodiment according to the present invention, the treatment fluid containing sodium chloride obtained by low-temperature treatment, After settling progress tentatively separation of solid and liquid, first time elutriation is carried out in eluriating tank with the ammonium salt-containing waste water, is then made again The liquid obtained when with subsequent wash sodium chloride crystal carries out second in another elutriation tank and eluriates, and will finally pass through twice Slurries after elutriation are sent into equipment for separating liquid from solid and are separated by solid-liquid separation, the crystal being separated by solid-liquid separation use again sodium-chloride water solution into Row elution, and the liquid that elution is obtained back in eluriating for the second time.By above-mentioned washing process, the chlorination that not only makes The purity of sodium crystal improves, and will not be excessive introducing cleaning solution, improve the efficiency of wastewater treatment.

In the present invention, there is no particular limitation for second vaporising device 1, can be commonly used in the art various MVR vaporising devices.Such as can be selected from MVR falling film evaporators, MVR forced-circulation evaporators, the evaporation of MVR-FC continuous crystallisations It is one or more in device, MVR-OSLO continuous crystallisation evaporators.Wherein, preferably MVR forced-circulation evaporators, MVR-FC connect Continuous crystallizing evaporator, more preferably falling liquid film+forced circulation two-stage MVR crystallizing evaporators.

In the present invention, there is no particular limitation for the evaporation conditions of second evaporation, can suitably select as needed, Achieve the purpose that make the first mother liquor concentrations.It is described second evaporation condition may include：Temperature is 35 DEG C or more, pressure To be more than -95kPa.In order to improve evaporation efficiency, the condition of preferably described second evaporation includes：Temperature is 45 DEG C~365 DEG C, pressure Power is -95kPa~18110kPa；Preferably, the condition of second evaporation includes：Temperature be 60 DEG C~365 DEG C, pressure be- 87kPa~18110kPa；Preferably, the condition of second evaporation includes：Temperature is 75 DEG C~175 DEG C, and pressure is -73kPa ~653kPa；Preferably, the condition of second evaporation includes：Temperature be 80 DEG C~130 DEG C, pressure be -66kPa~ 117kPa；Preferably, the condition of second evaporation includes：Temperature is 95 DEG C~110 DEG C, and pressure is -37kPa~12kPa；It is excellent Selection of land, it is described second evaporation condition include：Temperature is 95 DEG C~105 DEG C, and pressure is -37kPa~-7kPa.

In the present invention, the operating pressure of the second evaporation is preferably the saturated vapor pressure of evaporated feed liquid.

In addition, ability and pending wastewater flow rate that the evaporation capacity of the second evaporation can be handled according to equipment suitably select, Such as can be 100L/h or more (such as 0.1m³/ h~500m³/h)。

, can be while ensureing sulfate crystal by making the second evaporation carry out under these conditions, sodium chloride is not tied Crystalline substance, the purity for the sodium sulfate crystal that thereby may be ensured that.

According to the present invention, second evaporation is not so that (i.e. chlorination is precipitated in the sodium chloride crystallization in the pending waste water Sodium is not up to supersaturation), it is preferable that second evaporation makes a concentration of X or less of sodium chloride in the second concentrate (preferably 0.999X is hereinafter, more preferably 0.95X-0.999X, further preferred 0.99X-0.9967X).Wherein, X is in the second evaporation Under the conditions of, the concentration of sodium chloride when sodium chloride and sodium sulphate reach saturation in the second concentrate.Pass through the journey evaporated second Degree control within the above range, can be such that sulfate crystal as much as possible is precipitated under conditions of ensureing that sodium chloride is not precipitated. By making sulfate crystal in the second evaporation as possible, waste water treatment efficiency can be improved, energy waste is reduced.

In the present invention, the carry out degree of second evaporation is in such a way that the second evaporation of monitoring obtains the concentration of liquid It carries out, specifically, the concentration of liquid is obtained in above range by the second evaporation of control, the second evaporation is made described to wait locating The sodium chloride crystallization managed in waste water is precipitated.Here the second evaporation obtains the concentration of liquid, is supervised by way of measuring density It surveys, can specifically densitometer be used to carry out density measure.

According to the present invention, this method can also include the second concentrate by the sulfur acid sodium crystal in crystallization apparatus Crystallization obtains the magma of sulfur acid sodium crystal.Make in crystallization apparatus at this point, the evaporation conditions of second evaporation need to meet Sulfate crystal is precipitated and purpose that sodium chloride is not precipitated can (second evaporation makes the concentration of sodium chloride in the second concentrate For X or less).There is no particular limitation for the crystallization apparatus, such as can be brilliant flow container, brilliant liquid collecting tank, band stirring thickener Or without stirring thickener etc..A preferred embodiment according to the present invention, it is described crystallization in brilliant liquid collecting tank 55 into Row.There is no particular limitation for the condition of the crystallization, such as may include：Temperature be 45 DEG C or more, preferably 95 DEG C~107 DEG C, more preferably 85 DEG C~105 DEG C；Crystallization time can be 5min~for 24 hours, preferably 5min~30min.According to the present invention, The crystallization process of second concentrate of the sulfur acid sodium crystal can also be in the second vaporising device with crystallizer (as forced Circulation evaporation crystallizer) in carry out, the temperature crystallized at this time be it is corresponding second evaporation temperature.In the present invention, it crystallizes Temperature preferably with second evaporation temperature it is identical.

Second steam containing ammonia and the first mother liquor are carried out the second heat by a preferred embodiment according to the present invention It exchanges and obtains the second ammonium hydroxide.There is no particular limitation for the mode of second heat exchange, and changing for this field routine may be used Hot mode carries out.The number of second heat exchange can be preferably 2-4 times, more preferably 2-3 times more than primary, especially Preferably 2 times.By second heat exchange, the ammonium hydroxide of output is cooled, and heat utmostly recycles inside processing unit, The energy rationally is utilized, reduces waste.

In the case of, according to the invention it is preferred to, as shown in Figure 1, second heat exchange passes through 33 He of third heat-exchanger rig 4th heat-exchanger rig 34 carries out, and specifically, the second steam containing ammonia evaporated in second vaporising device 1 is led to successively The 4th heat-exchanger rig 34 and third heat-exchanger rig 33 are crossed, and by first mother liquor by third heat-exchanger rig 33, then with One mother liquor and second circulation liquid (the partial concentration liquid in second vaporising device 1) mixing, and obtained mixed liquor is passed through 4th heat-exchanger rig 34 carries out the second heat exchange, makes the first mother liquor heating be convenient for evaporating, while making described second to contain Ammonia steam condenses to obtain the second ammonium hydroxide, and second ammonium hydroxide can be stored in the second tank used for storing ammonia 52.

According to the present invention, after the second heat exchange, the temperature of first mother liquor is 42 DEG C or more, more preferably 52 DEG C ~372 DEG C, further preferably 82 DEG C~182 DEG C, be still more preferably 102 DEG C~112 DEG C.

A preferred embodiment according to the present invention, second evaporation process carry out in the second vaporising device 1, First mother liquor is passed through the second evaporation of progress in second vaporising device 1 by the 6th circulating pump 76 and obtains second containing ammonia Second concentrate of steam and sulfur acid sodium crystal.

In the present invention, sodium chloride is made not crystallize precipitation in order to reach second evaporation, described first is precipitated when evaporating Sodium sulfate crystal when the purpose that can be dissolved in low-temperature process, preferably make the condition of the second evaporation and low-temperature treatment full Foot：The temperature of second evaporation is at least 5 DEG C higher than the temperature of low-temperature treatment, preferably 20 DEG C high, more preferably 35 DEG C high~90 DEG C, It is further preferably 35 DEG C high~70 DEG C, it is particularly preferably 50 DEG C high~60 DEG C.The temperature with low-temperature treatment is evaporated by control second, When so that the first evaporation is precipitated sodium sulfate crystal and sodium chloride crystal, sodium sulphate therein can dissolve, and make the Sodium sulphate individually crystallizes precipitation in two evaporations, to improve the purity of obtained sodium sulphate and sodium chloride crystal.

In the present invention, the second concentrate of the sulfur acid sodium crystal that second evaporation obtains is separated by solid-liquid separation by second Obtain sodium sulfate crystal and the second mother liquor afterwards (i.e. second is separated by solid-liquid separation obtained liquid phase).Described second method being separated by solid-liquid separation does not have There is special restriction, such as can be selected from one or more in centrifugation, filtering and sedimentation.

According to the present invention, second separation of solid and liquid can (be, for example, centrifuge, belt by the second equipment for separating liquid from solid Filter, flame filter press etc.) 92 progress.After described second is separated by solid-liquid separation, the second equipment for separating liquid from solid 92 obtains second female Liquid returns to the first vaporising device 2 and carries out the first evaporation again, can specifically be returned to the second mother liquor by the 9th circulating pump 79 Second of pH value adjustment process.In addition, certain sulfate ion can be adsorbed, dissociate by being difficult to avoid that on obtained sodium sulfate crystal The impurity such as ammonia, hydroxide ion reduce the peculiar smell of solid salt to remove the impurity of absorption, reduce corrosivity, improve the crystalline substance The purity of body, it is preferable that sodium sulfate crystal water, the ammonium salt-containing waste water or metabisulfite solution carry out second and wash and do It is dry.In order to avoid the dissolving of sodium sulfate crystal in washing process, it is preferable that the sodium sulfate crystal is carried out with aqueous sodium persulfate solution Washing.It is highly preferred that the concentration of the aqueous sodium persulfate solution is preferably sodium sulphate at the temperature corresponding to sodium sulfate crystal to be washed Reach the concentration of sodium sulphate in the aqueous solution of saturation simultaneously with sodium chloride.

It is separated by solid-liquid separation the mode washed with second as above-mentioned second, there is no particular limitation, and ability can be used for example The elutriation apparatus and solid-liquid separating equipment of domain routine, which combine, to carry out, can also be in the equipment for separating liquid from solid such as band filter of segmentation Upper progress.Preferably, second washing includes eluriating and/or eluting.For above-mentioned elutriation and elution, there is no particular limitation, It can be carried out by the method for this field routine.It is described elutriation and elution number there is no particular limitation, can be 1 time with On, the sodium sulfate crystal of higher purity, preferably 2-4 times in order to obtain.During elutriation, use the ammonium salt-containing waste water as wash in a pan It does not recycle generally when washing lotion, can be used with circulated in countercurrent when doing elutriation liquid using the cleaning solution of the second washing recycling.It carries out Before the elutriation, tentatively separation of solid and liquid is carried out preferably by way of sedimentation and obtains the slurries (content liquid of sulfur acid sodium crystal For 35 mass % or less).During elutriation, relative to the slurries of 1 parts by weight sulfur acid sodium crystal, the liquid used is eluriated For 1~20 parts by weight.It is preferable to use aqueous sodium persulfate solution progress for elution.In order to further increase the effect of elutriation, purity is obtained Higher sodium sulfate crystal, in the case of preferred, the liquid that elution can be used to obtain is washed.The liquid generated for washing Body, it is preferable that before the ammonium salt-containing waste water eluriates second of pH value adjusting that liquid is back to before the evaporation of the first vaporising device 2, Other cleaning solutions are back to the second vaporising device 1, such as return to the second vaporising device 1 by the tenth circulating pump 80 and carry out the again Two evaporations.

A preferred embodiment according to the present invention obtains the second of sulfur acid sodium crystal dense by the second evaporation Contracting liquid carries out first time elutriation, then with the ammonium salt-containing waste water after settling progress tentatively separation of solid and liquid in eluriating tank It reuses the liquid obtained when subsequent wash sodium sulfate crystal and carries out second of elutriation in another elutriation tank, will finally pass through Slurries after eluriating twice are sent into the second equipment for separating liquid from solid and are separated by solid-liquid separation, and the crystal being separated by solid-liquid separation uses sodium sulphate again Aqueous solution is eluted, and the liquid that elution is obtained is used as back in eluriating for the second time and eluriates liquid.By above-mentioned elutriation and Elute the washing process combined, the purity of the sodium sulfate crystal not only made improves, and will not be excessive introducing cleaning solution, Improve the efficiency of wastewater treatment.

In the present invention, when carrying out the first evaporation and/or the second evaporation using MVR vaporising devices, in order to improve MVR evaporations Solid content in device, reduce liquid in ammonia content, preferably by by MVR vaporising devices evaporation after partially liq ( The liquid being located inside MVR vaporising devices, also referred to as circulation fluid) it flows back into MVR vaporising devices after heating and is evaporated again. It is not particularly limited as the ratio that the partially liq after the evaporation of MVR vaporising devices is flowed back into MVR vaporising devices, example Such as, the first reflux ratio of first evaporation can be 10-200, preferably 40-150, the second reflux ratio of second evaporation Can be 0.1-100, preferably 5-50.Here, reflux ratio refers to：Regurgitant volume and the total amount of liquid being sent into MVR vaporising devices Subtract the ratio of regurgitant volume.Preferably, the first circulation liquid in the first evaporation is preferably returned to the pH value tune before the first evaporation Before section is completed, as shown in Figure 1, can pump 72 by second circulation returns to the first heat-exchanger rig 31 by the first circulation liquid And mixed with pending waste water in the second waste water conveyance conduit between heat-exchanger rig 32, then passing through second of pH value After adjusting, heat exchange is carried out in the second heat-exchanger rig 32, is finally sent into first vaporising device 2.Preferably, second Second circulation liquid in evaporation is back to before the second heat exchange completes, as shown in Figure 1, can be by the 7th circulating pump 77 by institute State second circulation liquid be back to the 4th heat-exchanger rig 34 carry out heat exchange after, be finally sent into the second vaporising device 1.

In the present invention, using MVR vaporising devices carry out first evaporation and/or second evaporation when, this method further include by First steam containing ammonia and/or the second steam containing ammonia are compressed.The compression can be carried out by compressor, such as the first pressure Contracting machine 101 and the second compressor 102.By being compressed to containing ammonia steam, to input energy in MVR vapo(u)rization systems, ensure useless The process of water heating-evaporation-cooling is carried out continuously, and is needed to input startup steam when MVR evaporation processes start, is reached and continuously run It is only energized by compressor after state, it is no longer necessary to input other energy.The compressor may be used commonly used in the art Various compressors, such as centrifugal blower, turbocompressor or lobed rotor compressor etc..After compressor compresses, steam containing ammonia Temperature increase 5 DEG C~20 DEG C.

A preferred embodiment according to the present invention, first steam containing ammonia is cold by first heat exchange Remaining tail gas is coagulated to discharge after removing ammonia；Second steam containing ammonia is condensed remaining tail gas by second heat exchange to pass through Except being discharged after ammonia.As shown in Figure 1, first steam containing ammonia condenses remaining tail gas, that is, described the by first heat exchange The tail gas of two heat-exchanger rigs 32 discharge, second steam containing ammonia condense remaining tail gas the i.e. the 4th by second heat exchange The tail gas that heat-exchanger rig 34 is discharged.By the way that above-mentioned tail gas except ammonia, can be further decreased the pollutant load in emission, Make it can be with direct emission.

As the mode except ammonia, can be absorbed with tail gas absorber 83.The tail gas absorber 83 is without spy Other restriction can be various absorption towers commonly used in the art, such as tray absorption columns, packed absorber, falling film absorption Tower or void tower etc..There is recirculated water in the tail gas absorber 83, the recirculated water is under the action of the 4th circulating pump 74 in tail gas It is recycled in absorption tower 83, water can also be added to tail gas absorber 83 from circulating water pool 82 by third circulating pump 73, recycled Pond 82 can add fresh water, while can reduce by the temperature and ammonia content of 81 work water of vacuum pump.The tail gas absorber The type of flow of 83 inner exhaust gas and recirculated water can adverse current also can cocurrent, preferably adverse current.The recirculated water can be by additional Fresh water is supplemented.In order to ensure that tail gas fully absorbs, dilute sulfuric acid can also be further added in the tail gas absorber 83, To absorb a small amount of ammonia in tail gas etc..The recirculated water can be used as ammonium hydroxide or ammonium sulfate to be back to after absorbing tail gas It produces or sells.As the mode that above-mentioned tail gas is passed through to tail gas absorber 83, can be carried out by vacuum pump 81.

In the present invention, there is no particular limitation for the ammonium salt-containing waste water, as long as containing NH₄ ⁺、SO₄ ^2-、Cl^-And Na⁺It is useless Water.In addition, the method for the present invention is particularly suitable for the processing of high-salt wastewater.Dead catalyst as the present invention produces water, tool Body can be the waste water from molecular sieve, aluminium oxide or oil refining catalyst production process, and can also be will be from molecular sieve, oxidation Aluminium or the waste water of oil refining catalyst production process carry out the waste water after following removal of impurities and concentration.Molecular sieve, oxygen will preferably be come from The waste water for changing aluminium or oil refining catalyst production process carries out the waste water after following removal of impurities and concentration.

As the NH in the ammonium salt-containing waste water₄ ⁺Can be 8mg/L or more, preferably 300mg/L or more.

As the Na in the ammonium salt-containing waste water⁺Can be 510mg/L or more, preferably 1g/L or more, more preferably 2g/ L or more, further preferably 4g/L or more, further preferably 8g/L or more, further preferably 16g/L or more, further Preferably 32g/L or more, further preferably 40g/L or more, further preferably 50g/L or more, further preferably 60g/L More than.

As the SO in the ammonium salt-containing waste water₄ ^2-Can be 1g/L or more, preferably 2g/L or more, more preferably 4g/L More than, further preferably 8g/L or more, further preferably 16g/L or more, further preferably 32g/L or more, further Preferably 40g/L or more, further preferably 50g/L or more, further preferably 60g/L or more, further preferably 70g/L More than.

As the Cl in the ammonium salt-containing waste water^-Can be 970mg/L or more, more preferably 2g/L or more, further it is excellent Be selected as 4g/L or more, further preferably 8g/L or more, further preferably 16g/L or more, further preferably 32g/L with On, further preferably 40g/L or more, further preferably 50g/L or more, further preferably 60g/L or more.

The NH contained in the ammonium salt-containing waste water₄ ⁺、SO₄ ^2-、Cl^-And Na⁺The upper limit there is no particular limitation.Hold from waste water From the point of view of easily starting with, SO in ammonium salt-containing waste water₄ ^2-、Cl^-And Na⁺The upper limit be respectively 200g/L hereinafter, preferably 150g/L Below；NH in ammonium salt-containing waste water₄ ⁺For 100g/L hereinafter, preferably 50g/L or less.

From the efficiency for improving the first evaporation, from the point of view of the energy consumption for reducing processing procedure, relative in ammonium salt-containing waste water The SO contained₄ ^2-, the Cl in ammonium salt-containing waste water^-The higher the better for content, for example, relative to containing in 1 mole of ammonium salt-containing waste water SO₄ ^2-, the Cl that contains in the ammonium salt-containing waste water^-It is 1 mole or more, preferably 2 moles or more, preferably 5 moles or more, More preferably 9.5 moles or more, further preferably 10 moles or more.And from the point of view of practicability, relative to 1 mole of institute State the SO contained in ammonium salt-containing waste water₄ ^2-, the Cl that contains in the ammonium salt-containing waste water^-Preferably 200 moles hereinafter, more preferably 150 moles hereinafter, further preferably 100 moles hereinafter, still more preferably be 50 moles hereinafter, being still more preferably 30 Mole or less.Pass through the Cl that will contain in ammonium salt-containing waste water^-And SO₄ ^2-Molar ratio be limited to above range, can first steam Most of water is steamed in hair, reduces the circulation fluid scale of construction in system for handling, it is energy saving, keep processing procedure more economical.

In the present invention, the inorganic ion contained in the ammonium salt-containing waste water is in addition to NH₄ ⁺、SO₄ ^2-、Cl^-And Na⁺In addition, Mg can also be contained²⁺、Ca²⁺、K⁺、Fe³⁺, the inorganic ions such as rare earth element ion, Mg²⁺、Ca²⁺、K⁺、Fe³⁺, rare earth element from The respective content of the inorganic ions such as son is preferably 100mg/L hereinafter, more preferably 50mg/L is hereinafter, further preferably 10mg/L is not hereinafter, contain other inorganic ions particularly preferably.It, can by controlling other inorganic ions in above range To further increase the purity of finally obtained sodium chloride crystal and sodium sulfate crystal.In order to reduce in the ammonium salt-containing waste water The content of other inorganic ions preferably carries out following removal of impurities.

The TDS of the ammonium salt-containing waste water can be 1.6g/L or more, preferably 4g/L or more, more preferably 8g/L or more, Further preferably 16g/L or more, further preferably 32g/L or more, further preferably 40g/L or more, further preferably For 50g/L or more, further preferably 60g/L or more, further preferably 100g/L or more, further preferably 150g/L with On, further preferably 200g/L or more.

In the present invention, the pH value of the ammonium salt-containing waste water is preferably 4-8, such as 6.5-7.5.

In addition, due to the COD of waste water may block up film in concentration, in evaporative crystallization when influence the purity and color and luster etc. of salt, The COD more fewer better (preferably 20mg/L is hereinafter, more preferably 10mg/L or less) of the ammonium salt-containing waste water, is preferably pre-processing When by oxidation removal, such as bioanalysis, advanced oxidation processes progress specifically can be used, preferably used when COD contents are very high Oxidizing, the oxidant for example can be Fenton reagent.

In the present invention, in order to reduce the concentration impurity ion in ammonium salt-containing waste water, ensure the continuous-stable of processing procedure Carry out, reduce equipment operation maintenance cost, the ammonium salt-containing waste water using the present invention processing method handle before preferably through Removal of impurities.Preferably, the removal of impurities is one or more in separation of solid and liquid, chemical precipitation, absorption, ion exchange and oxidation.

Can be filtering, centrifugation, sedimentation etc. as the separation of solid and liquid；Can be to adjust as the chemical precipitation PH, carbonate deposition, magnesium salts precipitation etc.；Can be physical absorption and/or chemisorption, specific absorption as the absorption Agent can select activated carbon, silica gel, aluminium oxide, molecular sieve, natural clay etc.；As the ion exchange, strong acid may be used Any one in property resin cation, acidulous cation resin；As the oxidation, may be used commonly used in the art Various oxidants, such as ozone, hydrogen peroxide, potassium permanganate, in order to avoid introducing new impurity, it is preferred to use ozone, dioxygen Water etc..

Specific removal of impurities mode can be specifically chosen according to the dopant species contained in the ammonium salt-containing waste water.For suspension Object can select solid-liquid isolation method to clean；For inorganic matter and organic matter, chemical precipitation method, ion-exchange, suction can be selected Attached method removal of impurities, such as Subacidity cation exchange process, active carbon adsorption etc.；For organic matter, absorption and/or oxygen may be used The mode of change cleans, wherein preferably ozone biological activated carbon adsorption and oxidation method.A preferred embodiment party according to the present invention Formula, ammonium salt-containing waste water are removed by filtering, Subacidity cation exchange process, ozone biological activated carbon adsorption and oxidation method successively It is miscellaneous.By above-mentioned dedoping step, most suspended substances, hardness, silicon and organic matter can be removed, reduces device fouling risk, is protected Demonstrate,prove wastewater treatment process continuous and steady operation.

In the present invention, it for the lower ammonium salt-containing waste water of salt content, can be handled using the processing method of the present invention Before (preferably after above-mentioned removal of impurities), by concentrate make salt content reach the present invention ammonium salt-containing waste water required by range. Preferably, it is described concentration selected from ED films concentration and/or it is reverse osmosis；It is highly preferred that it is described be concentrated by ED films concentration and it is reverse osmosis It carries out, there is no particular limitation for the sequencing of the ED films concentration and reverse osmosis progress.The ED films concentration and reverse osmosis place The mode that this field routine may be used in reason device and condition carries out, and can be specifically chosen according to the case where pending waste water.Tool Body, it is concentrated as the ED films, unidirectional electrodialysis system or pole-reversing electroosmosis system can be selected to carry out；As the reverse osmosis Thoroughly, rolled film, plate membrane, dish tubular membrane, vibrating membrane or combinations thereof can be selected to carry out.Waste water can be improved by the concentration The efficiency of processing avoids energy waste caused by largely evaporating.

In the preferred embodiment of the present invention, waste water is that the waste water in process of producing molecular sieve is heavy by chemistry Form sediment, filtering, Subacidity cation exchange process and ozone biological activated carbon adsorption and oxidation method clean, and by the concentration of ED films and Waste water after reverse osmosis concentration.

Condition as above-mentioned chemical precipitation is preferably：Using sodium carbonate as inorganic agent, relative to 1 mole of calcium in waste water 1.2-1.4 mole of either sodium carbonate is added in ion, and the pH for adjusting waste water is more than 7, and reaction temperature is 20-35 DEG C, reaction time 0.5- 4h。

Condition as above-mentioned filtering is preferably：Filter element is situated between more using the double-layer filter material of anthracite and quartz sand composition Mass filter, anthracite granule size used are 0.7-1.7mm, quartz sand particle size 0.5-1.3mm, filtering velocity 10-30m/h.Filter The regeneration method of " gas backwash-gas and water backwash-water backwashing " is used to carry out media regeneration, regeneration period 10- after expecting use 15h。

Condition as above-mentioned Subacidity cation exchange process is preferably：PH value range is 6.5-7.5；Temperature≤40 DEG C, Resin layer height is 1.5-3.0m, regenerated liquid HCl concentration：4.5-5 mass %；Regenerant consumption (based on 100%), 50-60kg/ m³Wet resin；Regenerated liquid HCl flow velocitys are 4.5-5.5m/h, and regeneration time of contact is 35-45min；It is 18-22m/h just to wash flow velocity, It is 2-30min just to wash the time；Operation flow velocity is 15-30m/h；Langfang sanat can be used for example in acid cation exchange resin Chemical Co., Ltd., SNT board D113 acid cation exchange resins.

Condition as above-mentioned ozone biological activated carbon adsorption and oxidation method is preferably：The ozone residence time is 50-70min, Empty bed filtering velocity is 0.5-0.7m/h.

As above-mentioned ED films concentration condition be preferably：Electric current 145-155A, voltage 45-65V.It for example can be with as ED films For the ED films of Japanese A Sitong companies production.

It is preferably as above-mentioned reverse osmosis condition：Operating pressure 5.4-5.6MPa, 25-35 DEG C of inflow temperature, pH value are 6.5-7.5.It is for example carried out using the sea water desalination membrane TM810C that blue star Toray produces as reverse osmosis membrane.

It according to the present invention, when proceeding by wastewater treatment, can directly be gone into operation using ammonium salt-containing waste water, if ammonium salt-containing is useless The ion concentration of water meets the condition of the present invention, can first be carried out with condition according to the invention first evaporation, low-temperature treatment again into Row second evaporates；If the ion concentration of ammonium salt-containing waste water is unsatisfactory for the condition of the present invention, can control the first evaporation makes first In concentrate then the first concentrate is carried out low-temperature treatment and the second evaporation, obtained by the concentration of sodium sulphate close to concentration is precipitated Second concentrate is simultaneously separated by solid-liquid separation and obtains sodium sulfate crystal and the second mother liquor, then the second mother liquor is mixed with the ammonium salt-containing waste water To adjust the ion concentration of pending waste water sodium chloride crystal is obtained to carry out the first evaporation again after range of the presently claimed invention. Certainly Na can also be used in the starting stage₂SO₄Or the ion concentration in pending waste water is adjusted in NaCl, as long as making institute Pending waste water is stated to meet in the present invention to SO in pending waste water₄ ^2-、Cl^-Requirement.

The present invention will be described in detail by way of examples below.

In following embodiment, ammonium salt-containing waste water be process of producing molecular sieve in waste water successively pass through chemical precipitation, filtering, Subacidity cation exchange process and ozone biological activated carbon adsorption and oxidation method clean, and pass through the concentration of ED films and reverse osmosis successively Waste water after saturating method concentration.

Embodiment 1

As shown in Figure 1, by ammonium salt-containing waste water (159g/L containing NaCl, Na₂SO₄ 48g/L、NH₄Cl 39g/L、(NH₄)₂SO₄ 12g/L, pH 7) with inlet amount it is 5m³The speed of/h is sent into processing system by first circulation pump 71, is changed being sent to first The hydrogen of a concentration of 45.16 mass % is imported in the main pipeline of thermal 31 and the 5th heat-exchanger rig 35 (titanium alloy plate heat exchanger) Aqueous solution of sodium oxide carry out first time pH value adjusting, and by the first pH value measuring device 61 (pH meter) to the pH value after adjusting into Ammonium salt-containing waste water after the adjusting of the first pH value is respectively fed to 31 He of the first heat-exchanger rig by row monitoring (measured value 7.8) 5th heat-exchanger rig 35, the sulfur acid sodium crystal and sodium chloride obtained respectively with the first liquid of steam condensation containing ammonia and the first evaporation are brilliant First concentrate of body, which carries out the first heat exchange, makes ammonium salt-containing waste water be warming up to 102 DEG C；Then it is mixed to get and waits for the second mother liquor Handle the waste water (SO wherein contained₄ ^2-And Cl^-Molar ratio be 1：11.346), then pending waste water is being sent into the second heat exchange The sodium hydrate aqueous solution that a concentration of 45.16 mass % is imported in the pipeline of device 32 carries out second of pH value adjusting, and passes through Second pH value measuring device 62 (pH meter) is monitored (measured value 11) to the pH value after adjusting, is then fed into the second heat exchange dress Setting 32 (titanium alloy plate heat exchangers) and the first steam containing ammonia the first heat exchange of progress of recycling makes pending waste water be warming up to 112 DEG C, then by the pending waste water after the first heat exchange twice with 476.5m³/ h is sent into 2 (falling liquid film+pressure of the first vaporising device Cycle two-stage MVR crystallizing evaporators) it is evaporated, obtain the of the first steam containing ammonia and sulfur acid sodium crystal and sodium chloride crystal One concentrate.Wherein, the evaporation conditions of the first vaporising device 2 include：Temperature is 105 DEG C, and pressure is -7.02kPa, and evaporation capacity is 4.82m³/h.The first obtained steam containing ammonia (18 DEG C of temperature rise) after the compression of the first compressor 101 is evaporated to pass sequentially through Second heat-exchanger rig 32 and the first heat-exchanger rig 31 carry out heat exchange with pending waste water, cooling to obtain the first ammonium hydroxide, and the It is stored in one tank used for storing ammonia 51.In addition, in order to improve the solid content of concentrate in the first vaporising device 2, the first evaporation is filled It sets the partially liq after being evaporated in 2 and second heat-exchanger rig 32 is recycled to by second circulation pump 72, be then again introduced into the first steaming Transmitting apparatus 2 carries out the first evaporation (the first reflux ratio is 95.3).Pass through the mass flowmenter pair being arranged on the first vaporising device 2 The degree of one evaporation is monitored, and the evaporation capacity of the first evaporation of control is 4.82m³/ h (is equivalent to sodium sulphate in control process liquid A concentration of 0.978Y (88.9g/L)).

First concentrate of obtained sulfur acid sodium crystal and sodium chloride crystal is subjected to low temperature in low-temperature treatment tank 22 Processing, temperature are 20 DEG C, and time 60min obtains the treatment fluid of sodium chloride-containing crystal.

The treatment fluid of above-mentioned sodium chloride-containing crystal is sent into the first equipment for separating liquid from solid 91 (centrifuge) to be separated by solid-liquid separation, 7.17m is obtained per hour³Contain NaCl 279.8g/L, Na₂SO₄ 88.9g/L、NaOH 2.64g/L、NH₃The of 0.31g/L One mother liquor is temporarily stored into the first mother liquor tank 53, is separated by solid-liquid separation gained solid sodium chloride and (is obtained the chlorine of aqueous 15 mass % per hour Change sodium crystalli-zation cake 1190.32kg, wherein the content of sodium sulphate be 3.9 mass % or less) with sodium chloride crystalli-zation cake butt The sodium chloride solution of the equal 279.8g/L of quality elutes, dry in drying machine, obtains sodium chloride 1011.78kg per hour (purity is 99.5 weight %), after cleaning solution is sent into the second heat-exchanger rig 32 by the 8th circulating pump 78, is again introduced into the first steaming Transmitting apparatus 2 carries out the first evaporation.

Second evaporation process in the second vaporising device 1 (falling liquid film+forced circulation two-stage MVR crystallizing evaporators) into Row.The first mother liquor in above-mentioned first mother liquor tank 53 is sequentially sent to third heat-exchanger rig 33 and the 4th by the 6th circulating pump 76 After heat-exchanger rig 34, it is sent into the second evaporation of the second vaporising device 1 progress and obtains the second concentrate of sulfur acid sodium crystal.Wherein, The evaporation conditions of second vaporising device 1 include：Temperature is 105 DEG C, and pressure is -7.02kPa, evaporation capacity 0.78m³/h.In order to The solid content for improving concentrate in the second vaporising device 1, using in the second vaporising device 1 evaporate after the first mother liquor of part as Second circulation liquid is recycled to the 4th heat-exchanger rig 34 by the 7th circulating pump 77, is then again introduced into the progress of the second vaporising device 1 Second evaporation (the second reflux ratio is 9.6).Evaporate the second obtained steam containing ammonia (temperature after the compression of the second compressor 102 Rise 18 DEG C) the 4th heat-exchanger rig 34 and third heat-exchanger rig 33 are passed sequentially through, heat exchange is carried out with the first mother liquor, cooling obtains Second ammonium hydroxide, and stored in the second tank used for storing ammonia 52.It is steamed by the mass flowmenter pair second being arranged on the second vaporising device 1 The degree of hair is monitored, and controls a concentration of 0.9935X (306.5g/L) of the second evaporation concentrated solution sodium chloride.

Second concentrate of above-mentioned sulfur acid sodium crystal is sent into the second equipment for separating liquid from solid 92 (centrifuge) and carries out solid-liquid Separation, obtains 6.70m per hour³Contain NaCl 306.5g/L, Na₂SO₄ 52.5g/L、NaOH 2.89g/L、NH₃ 0.01g/L The second mother liquor, be temporarily stored into the second mother liquor tank 54.Second mother liquor is all recycled to first by the 9th circulating pump 79 to change Waste pipe between thermal 31 and the second heat-exchanger rig 32 is mixed to get pending waste water with ammonium salt-containing waste water.It is separated by solid-liquid separation Gained solid sodium sulfate (obtains the sulfate crystal filter cake 349.84kg that water content is 14 mass %, wherein sodium chloride per hour Content be 3.9 mass % or less) with after the elution of the metabisulfite solution of the 52.5g/L equal with sodium sulphate butt quality, dry It is dry in dry machine, sodium sulphate 300.87kg (purity is 99.5 weight %) is obtained per hour, and cleaning solution passes through the tenth circulating pump 80 It is recycled to the second vaporising device 1.

In addition, the second heat-exchanger rig 32 and the tail gas of the 4th heat-exchanger rig 34 discharge introduce tail gas absorption by vacuum pump 81 Tower 83 is absorbed, and recirculated water is connected in tail gas absorber 83, the recirculated water is under the action of the 4th circulating pump 74 in tail gas It is recycled in absorption tower 83, while water is added to tail gas absorber 83 from circulating water pool 82 by third circulating pump 73, and Fresh water is added in circulating water pool 82, reduces by the temperature and ammonia content of 81 work water of vacuum pump.In the tail gas absorber 83 It is further passed through dilute sulfuric acid, to absorb ammonia in tail gas etc..In addition, the initial period of MVR evaporations, is 143.3 by temperature DEG C steam started.

In the present embodiment, the ammonium hydroxide 4.82m of a concentration of 1.5 mass % is obtained in the first tank used for storing ammonia 51 per hour³, the The ammonium hydroxide 0.78m of a concentration of 0.28 mass % is obtained in two tank used for storing ammonia 52 per hour³, ammonium hydroxide can be back to the production of molecular sieve Process.

Embodiment 2

The processing of ammonium salt-containing waste water is carried out according to the method for embodiment 1, unlike：To containing NaCl 58g/L, Na₂SO₄ 120g/L、NH₄Cl 19g/L、(NH₄)₂SO₄The ammonium salt-containing waste water that 40g/L, pH are 7.1 is handled, and what is obtained is pending useless The SO contained in water₄ ^2-And Cl^-Molar ratio be 1：8.665.Heat is carried out by the first heat-exchanger rig 31 and the 5th heat-exchanger rig 35 The temperature of ammonium salt-containing waste water is 97 DEG C after exchange, and the temperature by pending waste water after the progress heat exchange of the second heat-exchanger rig 32 is 97.5℃.The evaporation conditions of first vaporising device 2 include：Temperature is 100 DEG C, and pressure is -22.83kPa, and evaporation capacity is 3.47m³/h.The temperature of low-temperature treatment is 25 DEG C, residence time 55min.The evaporation conditions of second vaporising device 1 include：Temperature Degree is 95 DEG C, and pressure is -36.36kPa, evaporation capacity 2.28m³/h。

First equipment for separating liquid from solid 91 obtains 454.10kg tons of the sodium chloride crystalli-zation cake of aqueous 14 mass % per hour, most Obtain sodium chloride 390.53kg per hour eventually (purity is 99.6 weight %)；25.59m is obtained per hour³A concentration of NaCl 280.6g/L、Na₂SO₄ 82.9g/L、NaOH 2.2g/L、NH₃The first mother liquor of 0.12g/L.

Second equipment for separating liquid from solid 92 obtains the sulfate crystal filter cake 962.68kg that water content is 15 mass % per hour, The final sodium sulphate 818.28kg (purity is 99.5 weight %) that obtains per hour obtains 23.56m per hour³, a concentration of NaCl 303.2g/L、Na₂SO₄ 55.3g/L、NaOH 2.4g/L、NH₃The second mother liquor of 0.005g/L.

In the present embodiment, the ammonium hydroxide 3.47m of a concentration of 2.2 mass % is obtained in the first tank used for storing ammonia 51 per hour³, the The ammonium hydroxide 2.28m of a concentration of 0.13 mass % is obtained in two tank used for storing ammonia 52 per hour³, ammonium hydroxide can be back to the production of molecular sieve Process.

Embodiment 3

The processing of ammonium salt-containing waste water is carried out according to the method for embodiment 1, unlike：To containing NaCl 80g/L, Na₂SO₄ 78g/L、NH₄Cl 29g/L、(NH₄)₂SO₄The ammonium salt-containing waste water that 28.7g/L, pH are 6.6 is handled, and what is obtained is pending useless The SO contained in water₄ ^2-And Cl^-Molar ratio be 1：8.745.Heat is carried out by the first heat-exchanger rig 31 and the 5th heat-exchanger rig 35 The temperature of ammonium salt-containing waste water is 105 DEG C after exchange, and the temperature of pending waste water after heat exchange is carried out by the second heat-exchanger rig 32 It is 117 DEG C.The evaporation conditions of first vaporising device 2 include：Temperature is 110 DEG C, pressure 11.34kPa, and evaporation capacity is 4.26m³/h.The evaporation conditions of second vaporising device 1 include：Temperature is 100 DEG C, and pressure is -22.82kPa, and evaporation capacity is 1.40m³/h.The temperature of low-temperature treatment is 20 DEG C, residence time 60min.

First equipment for separating liquid from solid 91 obtains 657.86kg tons of the sodium chloride crystalli-zation cake of aqueous 15 mass % per hour, most Obtain sodium chloride 559.18kg per hour eventually (purity is 99.4 weight %)；13.55m is obtained per hour³A concentration of NaCl 280.2g/L、Na₂SO₄ 89.1g/L、NaOH 1.7g/L、NH₃The first mother liquor of 0.18g/L.

Second equipment for separating liquid from solid 92 obtains the sulfate crystal filter cake 632.55kg that water content is 14 mass % per hour, It is final to obtain sodium sulphate 543.99kg per hour (purity is 99.5 weight %)；12.39m is obtained per hour³A concentration of NaCl 306.1g/L、Na₂SO₄ 53.9g/L、NaOH 1.85g/L、NH₃The second mother liquor of 0.0099g/L.

In the present embodiment, the ammonium hydroxide 4.26m of a concentration of 1.8 mass % is obtained in the first tank used for storing ammonia 51 per hour³, the The ammonium hydroxide 1.40m of a concentration of 0.16 mass % is obtained in two tank used for storing ammonia 52 per hour³, ammonium hydroxide can be back to the production of molecular sieve Process.

Embodiment 4

As shown in Fig. 2, by ammonium salt-containing waste water (149g/L containing NaCl, Na₂SO₄ 49g/L、NH₄Cl 45g/L、(NH₄)₂SO₄ 15g/L, pH 7.0) with inlet amount it is 5m³The speed of/h is sent in the pipeline of processing system, is being sent to the first heat exchange dress It sets in 31 or the 5th pipeline before heat-exchanger rig 35 (being titanium alloy plate heat exchanger) and imports a concentration of 45.16 mass % Sodium hydrate aqueous solution carries out first time pH value adjusting, and by the first pH value measuring device 61 (pH meter) to mixed pH value It is monitored (measured value 8), 71 are pumped by a part (4.5m of ammonium salt-containing waste water by first circulation³/ h) it is sent into the first heat exchange Device 31, carrying out the first heat exchange with the first liquid of steam condensation containing ammonia of recycling makes ammonium salt-containing waste water be warming up to 103 DEG C, remaining part It is distributed into the 5th heat-exchanger rig 35, carrying out the first heat exchange with the first concentrate makes ammonium salt-containing waste water be warming up to 103 DEG C, will contain ammonium After salt waste water converges and the second mother liquor is mixed to get the pending waste water (SO wherein contained₄ ^2-And Cl^-Molar ratio be 1： 11.227), then pending waste water is sent into the second heat-exchanger rig 32 and carries out the first heat exchange with the first steam containing ammonia, make to wait locating Reason waste water is warming up to 112 DEG C；Then pending waste water is sent in the pipeline of the first vaporising device 2 import it is a concentration of The sodium hydrate aqueous solution of 45.16 mass % carries out second of pH value adjusting, and passes through the second pH value measuring device 62 (pH meter) (measured value 10.8) is monitored to the pH value after adjusting, the pending waste water after second pH value is adjusted is sent into the One vaporising device 2 (falling liquid film+forced circulation two-stage MVR crystallizing evaporators) is evaporated, and obtains the first steam containing ammonia and sulfur acid First concentrate of sodium crystal and sodium chloride crystal.The first obtained steam containing ammonia is evaporated after the compression of the first compressor 101 (17 DEG C of temperature rise) passes sequentially through the second heat-exchanger rig 32 and the first heat-exchanger rig 31, respectively with pending waste water and ammonium salt-containing Waste water carries out heat exchange, and cooling obtains the first ammonium hydroxide, and is stored in the first tank used for storing ammonia 51.In addition, in order to improve the first steaming Partially liq after being evaporated in first vaporising device 2 is passed through second by the crystalline content of concentrate in transmitting apparatus 2 as circulation fluid Circulating pump 72 is recycled to the second heat-exchanger rig 32, is then again introduced into the first vaporising device 2 and carries out the first evaporation (reflux ratio is 92.6).The degree evaporated by the mass flowmenter pair first being arranged on the first vaporising device 2 is monitored, and control first is steamed The evaporation capacity of hair is 4.69m³/ h (a concentration of 0.976Y (83g/L) for being equivalent to sodium sulphate in control process liquid).Wherein, first The evaporation conditions of vaporising device 2 such as the following table 1：

Table 1

First concentrate of obtained sulfur acid sodium crystal and sodium chloride crystal is subjected to low temperature in low-temperature treatment tank 22 Processing, temperature are 25 DEG C, and residence time 55min obtains the treatment fluid of sodium chloride-containing crystal.

The treatment fluid of above-mentioned sodium chloride-containing crystal is sent into the first equipment for separating liquid from solid 91 (centrifuge) and carries out the first solid-liquid Separation, obtains 9.38m per hour³Contain NaCl 281g/L, Na₂SO₄ 83g/L、NaOH 1.66g/L、NH₃The of 0.18g/L One mother liquor is temporarily stored into the first mother liquor tank 53, is separated by solid-liquid separation gained solid sodium chloride and (is obtained the chlorine of aqueous 14 mass % per hour Change sodium crystalli-zation cake 1157.43kg, wherein the content of sodium sulphate be 3.6 mass % or less), with sodium chloride crystalli-zation cake butt The sodium chloride solution of the equal 281g/L of quality elutes, dry in drying machine, obtains sodium chloride 995.39kg (purity per hour For 99.4 weight %), after cleaning solution is sent into the second heat-exchanger rig 32 by the 8th circulating pump 78, it is again introduced into the first vaporising device 2 carry out the first evaporation.

Second evaporation process carries out in the second vaporising device 1, the second vaporising device 1 by 1st effective evaporator 1a, 2nd effect evaporator 1b, third effect evaporator 1c and fourth evaporator 1d (being forced-circulation evaporator) compositions.Pass through The first mother liquor in above-mentioned first mother liquor tank 53 is sequentially sent to the 4th heat-exchanger rig 34 and the 6th heat-exchanger rig by six circulating pumps 76 After 36 heat exchange, the second evaporation of each effect evaporator progress for being sequentially sent to the second vaporising device 1 obtains the second of sulfur acid sodium crystal Concentrate, evaporation conditions such as upper table 1.By the second steam containing ammonia that preceding 1st effective evaporator evaporates be passed through rear 1st effective evaporator into Row heat exchange simultaneously obtains condensation water, and further exchanges heat to obtain the second ammonium hydroxide in the 4th heat-exchanger rig 34 and the first mother liquor, and the 4th The second steam containing ammonia evaporated in effect evaporator 1d in third heat-exchanger rig 33 with cooling water (the ammonium salt-containing waste water) It carries out heat exchange and obtains the second ammonium hydroxide, the second ammonium hydroxide is merged and is stored in the second tank used for storing ammonia 52.In 1st effective evaporator Heating steam (life steam i.e. commonly used in the art) is passed through in 1a, heating steam obtains after being condensed in 1st effective evaporator 1a To condensate liquid be passed through the 6th heat-exchanger rig 36, further preheat the first mother liquor after for prepare washing solution.It is steamed by second The degree that the densitometer pair first being arranged on transmitting apparatus 1 evaporates is monitored, and controls the concentration of the second evaporation concentrated solution sodium chloride For 0.9935X (308.1g/L).By obtained the second concentrate of above-mentioned second vaporising device 1 evaporation in brilliant liquid collecting tank 55 into Row crystallization, crystallization temperature are 100 DEG C, and crystallization time 5min obtains the magma of sulfur acid sodium crystal.

The magma of above-mentioned sulfur acid sodium crystal is sent into the second equipment for separating liquid from solid 92 (centrifuge) to be separated by solid-liquid separation, often Hour obtains 8.70m³Contain NaCl 308.1g/L, Na₂SO₄ 53.9g/L、NaOH 1.82g/L、NH₃The second of 0.01g/L Mother liquor is temporarily stored into the second mother liquor tank 54, which is all recycled to the first heat-exchanger rig by the 9th circulating pump 79 31 and the second waste pipe between heat-exchanger rig 32 be mixed to get pending waste water with ammonium salt-containing waste water.It is separated by solid-liquid separation gained sulphur Sour sodium solid (obtains the sulfate crystal filter cake 378.37kg that water content is 15 mass %, the wherein content of sodium chloride per hour For 4.3 mass % or less) with after the 53.9g/L metabisulfite solutions elution equal with sodium sulphate butt quality, it is done in drying machine It is dry, obtain sodium sulphate 321.62kg (purity be 99.5 weight %) per hour, cleaning solution is recycled to the by the tenth circulating pump 80 Two vaporising devices 1.

In addition, the tail gas that the second heat-exchanger rig 32 and third heat-exchanger rig 33 are discharged introduces tail gas absorption by vacuum pump 81 Tower 83 is absorbed, and recirculated water is connected in tail gas absorber 83, the recirculated water is under the action of the 4th circulating pump 74 in tail gas It is recycled in absorption tower 83, while water is added to tail gas absorber 83 from circulating water pool 82 by third circulating pump 73, and Fresh water is added in circulating water pool 82, reduces by the temperature and ammonia content of 81 work water of vacuum pump.In the tail gas absorber 83 It is further passed through dilute sulfuric acid, to absorb ammonia in tail gas etc..In addition, the initial period of MVR evaporations, is 143.3 by temperature DEG C steam started.

In the present embodiment, the ammonium hydroxide 4.69m of a concentration of 1.8 mass % is obtained in the first tank used for storing ammonia 51 per hour³, the The ammonium hydroxide 0.99m of a concentration of 0.17 mass % is obtained in two tank used for storing ammonia 52 per hour³, ammonium hydroxide can be back to the production of molecular sieve Process.

Embodiment 5

The processing of ammonium salt-containing waste water is carried out according to the method for embodiment 4, unlike：To containing NaCl 69g/L, Na₂SO₄ 138g/L、NH₄Cl 12g/L、(NH₄)₂SO₄The ammonium salt-containing waste water that 24.4g/L, pH are 7.1 is handled, and what is obtained is pending The SO contained in waste water₄ ^2-And Cl^-Molar ratio be 1：9.085.It is carried out by the first heat-exchanger rig 31 and the 5th heat-exchanger rig 35 The temperature of ammonium salt-containing waste water is 104 DEG C after heat exchange, and the temperature of pending waste water after heat exchange is carried out by the second heat-exchanger rig 32 Degree is 114 DEG C.Evaporation conditions such as the following table 2 of first vaporising device 2 and the second vaporising device 1.The temperature of low-temperature treatment is 30 DEG C, Residence time is 50min.

Table 2

First equipment for separating liquid from solid 91 obtains 475.12kg tons of the sodium chloride crystalli-zation cake of aqueous 14 mass % per hour, most Obtain sodium chloride 408.95kg per hour eventually (purity is 99.4 weight %)；26.11m is obtained per hour³A concentration of NaCl 283.4g/L、Na₂SO₄ 79.9g/L、NaOH 2.66g/L、NH₃The first mother liquor of 0.077g/L.

Second equipment for separating liquid from solid 92 obtains the sulfate crystal filter cake 968.12kg that water content is 15 mass % per hour, It is final to obtain sodium sulphate 822.91kg per hour (purity is 99.5 weight %)；24.04m is obtained per hour³, a concentration of NaCl 306.3g/L、Na₂SO₄ 52.5g/L、NaOH 2.97g/L、NH₃The second mother liquor of 0.003g/L.

In the present embodiment, the ammonium hydroxide 3.31m of a concentration of 1.4 mass % is obtained in the first tank used for storing ammonia 51 per hour³, the The ammonium hydroxide 2.32m of a concentration of 0.08 mass % is obtained in two tank used for storing ammonia 52 per hour³, ammonium hydroxide can be back to the production of molecular sieve Process.

Embodiment 6

The processing of ammonium salt-containing waste water is carried out according to the method for embodiment 4, unlike：To containing NaCl 106g/L, Na₂SO₄ 103g/L、NH₄Cl 21g/L、(NH₄)₂SO₄The ammonium salt-containing waste water that 20.7g/L, pH are 7.2 is handled, and what is obtained is pending The SO contained in waste water₄ ^2-And Cl^-Molar ratio be 1：9.189.It is carried out by the first heat-exchanger rig 31 and the 5th heat-exchanger rig 35 The temperature of ammonium salt-containing waste water is 103 DEG C after heat exchange, and the temperature of pending waste water after heat exchange is carried out by the second heat-exchanger rig 32 Degree is 112 DEG C.Evaporation conditions such as the following table 3 of first vaporising device 2 and the second vaporising device 1.The temperature of low-temperature treatment is 25 DEG C, Residence time is 55min.

Table 3

First equipment for separating liquid from solid 91 obtains 757.97kg tons of the sodium chloride crystalli-zation cake of aqueous 15 mass % per hour, most Obtain sodium chloride 644.27kg per hour eventually (purity is 99.4 weight %)；19.57m is obtained per hour³A concentration of NaCl 280.4g/L、Na₂SO₄ 82.7g/L、NaOH 2.64g/L、NH₃The first mother liquor of 0.15g/L.

Second equipment for separating liquid from solid 92 obtains the sulfate crystal filter cake 737.81kg that water content is 15 mass % per hour, It is final to obtain sodium sulphate 627.14kg per hour (purity is 99.5 weight %)；18.09m is obtained per hour³, a concentration of NaCl 303.2g/L、Na₂SO₄ 55.1g/L、NaOH 2.85g/L、NH₃The second mother liquor of 0.0049g/L.

In the present embodiment, the ammonium hydroxide 3.86m of a concentration of 1.4 mass % is obtained in the first tank used for storing ammonia 51 per hour³, the The ammonium hydroxide 1.76m of a concentration of 0.16 mass % is obtained in two tank used for storing ammonia 52 per hour³, ammonium hydroxide can be back to the production of molecular sieve Process.

The preferred embodiment of the present invention has been described above in detail, still, during present invention is not limited to the embodiments described above Detail can carry out a variety of simple variants to technical scheme of the present invention within the scope of the technical concept of the present invention, this A little simple variants all belong to the scope of protection of the present invention.

It is further to note that specific technical features described in the above specific embodiments, in not lance In the case of shield, it can be combined by any suitable means.In order to avoid unnecessary repetition, the present invention to it is various can The combination of energy no longer separately illustrates.

In addition, various embodiments of the present invention can be combined randomly, as long as it is without prejudice to originally The thought of invention, it should also be regarded as the disclosure of the present invention.

Claims

1. a kind of processing method of ammonium salt-containing waste water, the ammonium salt-containing waste water contain NH₄ ⁺、SO₄ ^2-、Cl^-And Na⁺, which is characterized in that it should Method includes the following steps,

1) pending waste water is subjected to the first evaporation, obtains the first concentrate of the first steam containing ammonia and sodium chloride-containing crystal, institute It states pending waste water and contains the ammonium salt-containing waste water；

3) treatment fluid of the sodium chloride-containing crystal first is carried out to be separated by solid-liquid separation, and by first be separated by solid-liquid separation obtained liquid phase into Row second evaporates, and obtains the second concentrate of the second steam containing ammonia and sulfur acid sodium crystal；

Wherein, before the pending waste water is carried out the first evaporation, the pH value for adjusting the pending waste water is more than 9；

Second evaporation makes sodium chloride crystal not crystallize precipitation；

Relative to the SO contained in 1 mole of pending waste water₄ ^2-, the Cl that contains in the pending waste water^-It is 7.15 moles More than.

2. according to the method described in claim 1, wherein, the pending waste water is the ammonium salt-containing waste water；Alternatively, described wait for Processing waste water contains the ammonium salt-containing waste water and described second and is separated by solid-liquid separation obtained liquid phase；

Preferably, relative to the SO contained in 1 mole of pending waste water₄ ^2-, the Cl that contains in the pending waste water^-For 9.5 moles or more；

Preferably, relative to the SO contained in 1 mole of pending waste water₄ ^2-, the Cl that contains in the pending waste water^-It is 10 Mole or more；

Preferably, before the pending waste water is carried out the first evaporation, the pH value for adjusting the pending waste water is more than 10.8；

Preferably, the pH value for adjusting the pending waste water is carried out using NaOH.

3. method according to claim 1 or 2, wherein the first concentrate of the sodium chloride-containing crystal also contains sulfuric acid Sodium crystal；And when the first concentrate of the sodium chloride-containing crystal also contains sodium sulfate crystal, the low-temperature treatment makes sulfuric acid Sodium crystal dissolves, and obtains the treatment fluid of the sodium chloride-containing crystal.

Preferably, first evaporation makes a concentration of Y or less of sodium sulphate in the treatment fluid, wherein Y is in low-temperature treatment Under the conditions of, the concentration of sodium sulphate when sodium chloride and sodium sulphate reach saturation in the treatment fluid；

Second evaporation makes a concentration of X or less of sodium chloride in second concentrate, wherein X is the item in the second evaporation Under part, the concentration of sodium chloride when sodium chloride and sodium sulphate reach saturation in second concentrate；

Preferably, first evaporation makes a concentration of 0.9Y-0.99Y of sodium sulphate in the treatment fluid；

Preferably, second evaporation makes a concentration of 0.95X-0.999X of sodium chloride in second concentrate.

4. according to the method described in any one of claim 1-3, wherein it is described first evaporation condition include：Temperature is 35 DEG C or more, pressure is -95kPa or more；

Preferably, the condition of first evaporation includes：Temperature is 45 DEG C~175 DEG C, and pressure is -95kPa~18110kPa；

Preferably, the condition of first evaporation includes：Temperature is 60 DEG C~175 DEG C, and pressure is -87kPa~18110kPa；

Preferably, the condition of first evaporation includes：Temperature is 75 DEG C~175 DEG C, and pressure is -73kPa~653kPa；

Preferably, the condition of first evaporation includes：Temperature is 80 DEG C~130 DEG C, and pressure is -66kPa~117kPa；

Preferably, the condition of first evaporation includes：Temperature is 95 DEG C~110 DEG C, and pressure is -37kPa~12kPa.

5. according to the method described in any one of claim 1-3, wherein it is described second evaporation condition include：Temperature is 35 DEG C or more, pressure is -95kPa or more；

Preferably, the condition of second evaporation includes：Temperature is 45 DEG C~365 DEG C, and pressure is -95kPa~18110kPa；

Preferably, the condition of second evaporation includes：Temperature is 60 DEG C~365 DEG C, and pressure is -87kPa~18110kPa；

Preferably, the condition of second evaporation includes：Temperature is 75 DEG C~175 DEG C, and pressure is -73kPa~653kPa；

Preferably, the condition of second evaporation includes：Temperature is 80 DEG C~130 DEG C, and pressure is -66kPa~117kPa；

Preferably, the condition of second evaporation includes：Temperature is 95 DEG C~110 DEG C, and pressure is -37kPa~12kPa.

6. according to the method described in any one of claim 1-3, wherein the condition of the low-temperature treatment includes：Temperature is 13 DEG C~100 DEG C, preferably 15 DEG C~45 DEG C, more preferably 15 DEG C~35 DEG C, further preferably 17.9 DEG C~35 DEG C.

7. method according to claim 5 or 6, wherein the temperature of second evaporation is 5 DEG C higher than the temperature of low-temperature treatment More than, it is preferably high 20 DEG C or more, more preferably 35 DEG C high~90 DEG C.

8. method according to any one of claims 1-7, wherein first evaporation and the second evaporation difference Pass through one or more progress in MVR vaporising devices, single-effect evaporating equipment and multi-effect evaporating device；

Preferably, first evaporation is carried out by MVR vaporising devices；

Preferably, second evaporation is carried out by MVR vaporising devices.

9., will be described before the pending waste water is carried out the first evaporation according to the method described in claim 1, wherein The condensation water of first steam containing ammonia or first steam containing ammonia and the pending waste water carry out the first heat exchange and obtain the One ammonium hydroxide；

Preferably, before carrying out first heat exchange, the pH value for adjusting the pending waste water is more than 7.

10. according to the method described in any one of claim 1-9, this method further includes by the place of the sodium chloride-containing crystal Reason liquid obtains sodium chloride crystal after first is separated by solid-liquid separation；

Preferably, this method further includes being washed to obtained sodium chloride crystal.

11. according to the method described in any one of claim 1-9, this method further includes by the of the sulfur acid sodium crystal Two concentrates obtain sodium sulfate crystal after second is separated by solid-liquid separation；

Preferably, this method further includes being washed to obtained sodium sulfate crystal.

12. according to the method described in any one of claim 1-9, wherein NH in the ammonium salt-containing waste water₄ ⁺For 8mg/L with On, SO₄ ^2-For 1g/L or more, Cl^-For 970mg/L or more, Na⁺For 510mg/L or more；

Preferably, the ammonium salt-containing waste water is the waste water from molecular sieve, aluminium oxide or oil refining catalyst production process；

Preferably, this method further includes that the ammonium salt-containing waste water is cleaned and concentrated.