CN108726759A

CN108726759A - The processing method of ammonium salt-containing waste water

Info

Publication number: CN108726759A
Application number: CN201710263286.6A
Authority: CN
Inventors: 殷喜平; 李叶; 顾松园; 陈玉华; 刘志坚; 安涛; 张志民; 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: CN108726759B

Abstract

The present invention relates to sewage treatment fields, disclose the processing method of ammonium salt-containing waste water, which contains NH₄ ⁺、SO₄ ^2‑、Cl^‑And Na⁺, this approach includes the following steps, 1) and it pending waste water is subjected to the first evaporation obtains the first concentrate of the first steam containing ammonia and sodium chloride-containing crystal, the pending waste water contains the ammonium salt-containing waste water；2) the first concentrate 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 the second evaporation of liquid phase progress and obtains the second concentrate of the second steam containing ammonia and sulfur acid sodium crystal；3) 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 is not reduced in waste water (20000mg/L~30000mg/L), 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 (20000mg/L~30000mg/L), Bu Nengzhi Running in and put, needs further to carry out desalting processing, wastewater treatment operating cost is high, and a large amount of alkali is remained in treated waste water, PH value is very high, and 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 Ammonium and sodium chloride, sodium sulphate in ammonium salt-containing waste water can be separately recovered in ammonium salt-containing wastewater treatment method, this method, utmostly Ground recycles the resource in waste water.

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 and obtains the first concentrate of the first steam containing ammonia and sodium chloride-containing crystal, The pending waste water contains the ammonium salt-containing waste water；

2) the first concentrate 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 and is obtained Liquid phase carry out second evaporation obtain the second concentrate of the second steam containing ammonia and sulfur acid sodium crystal；

3) 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；First evaporation makes sodium sulphate not crystallize precipitation, and second evaporation makes sodium chloride not crystallize precipitation；Relative to 1 mole of institute State the SO contained in pending waste water₄ ^2-, the Cl that contains in the pending waste water^-It is 9.5 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, recycles the isolated sodium chloride crystal of the first evaporation and compared with concentrated ammonia liquor, then recycle Second evaporation obtains sodium sulfate crystal and compared with weak aqua ammonia.This method can respectively obtain the sodium chloride and sodium sulphate of high-purity, keep away Difficulty during having exempted from mixed salt processing and having recycled, is completed at the same time separation of ammonia and the process of salt, and use heat exchange method Make waste water heating and steam cooling containing ammonia simultaneously, is not necessarily to condenser, energy saving rationally using the heat in evaporation process, 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.

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

31, the first heat-exchanger rig 74, the 4th circulating pump

32, the second heat-exchanger rig 75, the 5th circulating pump

33, third heat-exchanger rig 76, the 6th circulating pump

34, the 4th heat-exchanger rig 77, the 7th circulating pump

35, the 5th heat-exchanger rig 78, the 8th circulating pump

4, vacuum receiver 79, the 9th circulating pump

51, the first tank used for storing ammonia 81, vacuum pump

52, the second tank used for storing ammonia 82, circulating water pool

53, the first mother liquor tank 83, tail gas absorber

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

55, brilliant liquid collecting 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 and Fig. 2, the present invention will be described, and the present invention is not limited by Fig. 1 and Fig. 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,

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 pending 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 9.7 moles or more, more preferably 10 moles or more, more preferably 10.5 moles or more, more preferably 11 moles or more, preferably 50 moles hereinafter, more preferably 40 moles hereinafter, further preferably 30 moles hereinafter, for example can be 11-20 moles, preferably It is 11-15 moles.By by SO₄ ^2-And Cl^-Molar ratio control in above range, sodium chloride can be made to be precipitated in the first evaporation And sodium sulphate is not precipitated, to achieve the purpose that efficiently separate sodium chloride.In addition, it is as above described below, may be used also in the present invention With the second Recycling Mother Solution for will being obtained in the second evaporation process to the first evaporation, and thus come 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 sulphate not crystallize precipitation, refers to that the sodium sulphate of control mixed system is dense Degree is no more than the solubility under the first evaporation conditions (including but not limited to temperature, pH value etc.), it is not excluded that sodium chloride crystallization folder The sodium sulphate of band or adsorption.Since the water content of crystal after separation of solid and liquid is different, sulphur in the sodium chloride crystal generally yielded The content of sour sodium is below 8 mass % the case where (preferably 4 mass % or less), so that it may to think that sodium sulphate does not crystallize precipitation.

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 The content of change sodium is below 8 mass % the case where (preferably 4 mass % or less), so that it may to think that sodium chloride does not crystallize precipitation.

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 includes each effect evaporator of multi-effect evaporating device Evaporation conditions.

In the present invention, it is described first evaporation condition can suitably select as needed, reach make sodium chloride crystallize and Make the purpose that sodium sulphate is not precipitated.It is described first evaporation condition may include：Temperature be 30 DEG C~85 DEG C, pressure be- 98kPa~-58kPa.In order to improve evaporation efficiency, and from the point of view of reducing equipment cost and energy consumption, it is preferable that described the One evaporation condition include：Temperature is 35 DEG C~60 DEG C, and pressure is -97.5kPa~-87kPa；It is highly preferred that described first steams The condition of hair includes：Temperature is 40 DEG C~60 DEG C, and pressure is -97kPa~-87kPa；It is further preferred that first evaporation Condition include：Temperature is 45 DEG C~60 DEG C, and pressure is -95kPa~-87kPa；It is particularly preferred that the item of first evaporation Part includes：Temperature is 45 DEG C~55 DEG C, and pressure is -95kPa~-90kPa.

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)。

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

Contained ammonia in the pending waste water can be evaporated by the condition of the first evaporation of control according to the present invention 90 mass % or more (preferably 95 mass % or more), to obtain higher first ammonium hydroxide of concentration, the first ammonium hydroxide can be direct Be back to the production process of catalyst, either with acid neutralization obtain carrying out after ammonium salt reuse or with water and corresponding ammonium salt or Ammonium hydroxide allotment uses.

According to the present invention, first evaporation is not so that (i.e. sulfuric acid is precipitated in the sulfate crystal in the pending waste water Sodium is not up to supersaturation), it is preferable that first evaporation makes a concentration of Y or less of sodium sulphate in the first concentrate (preferably 0.9Y-0.99Y, more preferably 0.95Y-0.98Y).Wherein, Y is the sodium chloride in the first concentrate under conditions of first evaporates The concentration of sodium sulphate when reaching saturation with sodium sulphate.By by first evaporation extent control within the above range, Ke Yi Ensure to make sodium chloride crystallization as much as possible be precipitated under conditions of sodium sulphate is not precipitated.By making chlorination in the first evaporation as possible Sodium crystallizes, and can improve waste water treatment efficiency, reduces energy waste.

In the present invention, the carry out degree of first evaporation is in such a way that the first evaporation of monitoring obtains the concentration of liquid It carries out, specifically, the concentration for obtaining liquid by the first evaporation of control makes the first evaporation not make described in above-mentioned range Sulfate crystal in first concentrate is precipitated.Here first evaporation obtain the concentration of liquid, by way of measuring density into Row monitoring can specifically use densitometer to carry out density measure.

According to the present invention, first evaporation carries out in the first vaporising device 2 (first vaporising device is as described above). By first circulation pump 71 by pending waste water be passed through the first vaporising device 2 carry out first evaporation, obtain the first steam containing ammonia with First concentrate of sodium chloride-containing crystal.

According to the present invention, this method can also include by the first concentrate of the sodium chloride-containing crystal in the first crystallization dress It sets the first crystallization of middle progress and obtains the magma of sodium chloride-containing crystal.At this point, the evaporation conditions of first evaporation need to meet Sodium chloride is set to crystallize and purpose that sodium sulphate is not precipitated in first crystallization process.First crystallization apparatus does not limit particularly It is fixed, such as can be brilliant flow container, brilliant liquid collecting tank, with stirring thickener or without stirring thickener etc..First crystallization Condition can be selected suitably, such as may include：Temperature is 30 DEG C or more；Preferably 40 DEG C~60 DEG C；More preferably 45 DEG C~ 55℃.In order to fully ensure that the effect of crystallization, crystallization time can be 5min~for 24 hours, preferably 5min~30min.According to this Invention, the first crystallization process of the first concentrate of the sodium chloride-containing crystal can also with crystallizer vaporising device (such as Forced-circulation evaporation crystallizer) in carry out, at this time first crystallization temperature be it is corresponding first evaporation temperature.

According to the present invention, when being crystallized using individual crystallization apparatus, need to be further ensured that first evaporation makes It obtains sodium sulphate and does not crystallize precipitation in the first crystallization process (i.e. sodium sulphate is not up to supersaturation), it is preferable that first evaporation Make a concentration of Y or less (preferably 0.9Y-0.99Y, more preferably 0.95Y-0.98Y) of sodium sulphate in first concentrate, Wherein, Y is sodium sulphate when sodium sulphate and sodium chloride reach saturation in the first concentrate under conditions of first crystallization Concentration.

A preferred embodiment according to the present invention will before the pending waste water is carried out the first evaporation The condensation water of first steam containing ammonia or first steam containing ammonia carries out the first heat exchange with the pending waste water and obtains To the first ammonium hydroxide.There is no particular limitation for the mode of first heat exchange, may be used the heat exchange mode of this field routine into Row.The number of first heat exchange can be 1 time or more, preferably 2-4 times, more preferably 2-3 times.Pass through first heat After exchange, the ammonium hydroxide of output 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, first heat exchange pass through the first heat-exchanger rig 31 and second Heat-exchanger rig 32 carries out, and specifically, by the first steam containing ammonia evaporated in first vaporising device 2, (or first contain The condensation water of ammonia steam) the second heat-exchanger rig 32 and the first heat-exchanger rig 31 are passed sequentially through, and successively by the pending waste water By the first heat-exchanger rig 31 and the second heat-exchanger rig 32, institute is carried out by first steam containing ammonia and the pending waste water The first heat exchange is stated, makes pending waste water heating be convenient for evaporating, while the first steam cooling containing ammonia being made to obtain the first ammonium hydroxide, First ammonium hydroxide can be stored in the first tank used for storing ammonia 51.

Another preferred embodiment according to the present invention, as shown in Figure 1, first heat exchange passes through the first heat exchange Device 31, the second heat-exchanger rig 32 and the 5th heat-exchanger rig 35 carry out, and specifically, will be evaporated in first vaporising device 2 The first obtained steam containing ammonia passes sequentially through the second heat-exchanger rig 32 and the first heat-exchanger rig 31, second that the second evaporation is obtained The condensation water of the steam containing ammonia is (for example, the second steam containing ammonia carries out the second heat in third heat-exchanger rig 33 and the 4th heat-exchanger rig 34 The condensation water obtained after exchange) by the 5th heat-exchanger rig 35, and by the pending waste water in part by the 5th heat-exchanger rig 35, together When by the pending waste water of another part by the first heat-exchanger rig 31, then the pending waste water of above-mentioned two parts is converged, and with After second mother liquor is mixed to get pending waste water, then by the pending waste water by the second heat-exchanger rig 32, described the is completed The first heat exchange between one steam containing ammonia and pending waste water.

In the present invention, do not have for first heat-exchanger rig 31, the second heat-exchanger rig 32 and the 5th heat-exchanger rig 35 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 first steam containing ammonia or the first steam containing ammonia condensation water thermal energy, preferably After the first heat exchange, the temperature of the pending waste water is 41 DEG C~67 DEG C, more preferably 47 DEG C~62 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, such as can be the hydroxide such as sodium hydroxide, potassium hydroxide.In order not to be introduced newly in pending waste water Impurity improves the purity of gained crystal, and the alkaline matter is preferably 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, before pending waste water to be sent into the first heat-exchanger rig 31 or the first heat exchange of progress of the 5th heat-exchanger rig 35, By being sent into the pipeline of the first heat-exchanger rig 31 or the 5th heat-exchanger rig 35 described in importing containing alkalinity by pending waste water The aqueous solution of substance and mixing, to carry out first time pH value adjusting；Then by pending waste water be sent into the second heat-exchanger rig 32 into The first heat exchange of row, and contain basic species the pending waste water to be sent into the pipeline of the second heat-exchanger rig 32 described in importing The aqueous solution of matter and mixing, to carry out second of pH value adjusting.It is adjusted by pH value twice, the pending waste water is made to be passed through PH value before first vaporising device 2 is more than 9, preferably greater than 10.8.Preferably, first time pH value is adjusted so that adjusting The pH value of pending waste water afterwards is more than 7 (preferably 7-9), and second of pH value adjusts the pH so that the pending waste water after adjusting Value is more than 9, preferably greater than 10.8.

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 or 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, before the pending waste water is passed through the first vaporising device complete.

In the present invention, the first concentrate of the sodium chloride-containing crystal obtains sodium chloride crystalline substance after first is separated by solid-liquid separation Body and the 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.

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, which preferably carries out in the device well known in the art such as settling tank, settling tank).It eluriated Cheng Zhong, relative to the slurries of 1 parts by weight sodium chloride-containing crystal, it is 1~20 parts by weight to eluriate the liquid used.In addition, elution is excellent Choosing is carried out using sodium-chloride water solution.Preferably, the concentration of the sodium-chloride water solution is preferably in sodium chloride crystal institute to be washed Sodium chloride and sodium sulphate reach the concentration of sodium chloride in the aqueous solution of saturation simultaneously under corresponding temperature.It is eluriated to further increase Effect, obtain the higher sodium chloride crystal of purity, in the case of preferred, the liquid that elution obtain can be used to carry out above-mentioned wash in a pan It washes, it is preferable to use water or sodium chloride solution.For the liquid that washing generates, the first heat before the first evaporation is preferably returned it to It exchanges before completing.

A preferred embodiment according to the present invention contains sodium chloride by what the evaporation of the first vaporising device 2 obtained The first concentrate, by the way that after settling and be tentatively separated by solid-liquid separation, first time is carried out in eluriating tank with the ammonium salt-containing waste water It eluriates, then reuses the liquid obtained when subsequent wash sodium chloride crystal and carry out second of elutriation in another elutriation tank, Equipment for separating liquid from solid finally will be sent by the slurries eluriated twice to be separated by solid-liquid separation, the crystal being separated by solid-liquid separation uses chlorine again Change the liquid that sodium water solution is eluted, and elution is obtained to return in second of elutriation.By above-mentioned washing process, not only The purity of the sodium chloride crystal made improves, and will not be excessive introducing cleaning solution, improve the efficiency of wastewater treatment.

In the present invention, the evaporation conditions of second evaporation can be selected suitably as needed, and reaching makes sodium sulphate knot Brilliant and purpose that sodium chloride is not precipitated.It is described second evaporation condition may include：Temperature be 45 DEG C or more, pressure be- 95kPa or more.In order to improve evaporation efficiency, and from the point of view of reducing equipment cost and energy consumption, it is preferable that described second steams The condition of hair includes：Temperature is 45 DEG C~365 DEG C, and pressure is -95kPa~18110kPa；Preferably, the item of second evaporation Part includes：Temperature is 60 DEG C~365 DEG C, and pressure is -87kPa~18110kPa；Preferably, the condition packet of second evaporation It includes：Temperature is 75 DEG C~175 DEG C, and pressure is -73kPa~653kPa；Preferably, the condition of second evaporation includes：Temperature It it is 80 DEG C~130 DEG C, pressure is -66kPa~117kPa；It is particularly preferred that the condition of second evaporation includes：Temperature is 95 DEG C~105 DEG C, 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 0.1m³/ 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 sodium chloride crystallization precipitation (i.e. sodium chloride is not up to supersaturation), excellent Selection of land, it is described second evaporation make sodium chloride in second concentrate a concentration of X or less (preferably 0.9X-0.99X, it is more excellent It is selected as 0.95X-0.999X, further preferably 0.99X-0.9967X), wherein X is under conditions of second evaporates, and second is dense The concentration of sodium chloride when sodium chloride and sodium sulphate reach saturation in contracting liquid.By by second evaporation extent control in above-mentioned model In enclosing, sulfate crystal as much as possible can be made to be precipitated under conditions of ensureing that sodium chloride is not precipitated.By as possible second Make sulfate crystal in evaporation, waste water treatment efficiency can be improved, reduces energy waste.

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 for obtaining liquid by the second evaporation of control makes the second evaporation not make described second in above range Sodium chloride crystallization in concentrate 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, second evaporation carries out in the second vaporising device 1 (second vaporising device is as described above). First mother liquor is passed through the second evaporation of progress in second vaporising device 1 and obtains the second steam containing ammonia and sodium chloride-containing crystalline substance Second concentrate of body.

According to the present invention, this method can also include by the second concentrate of the sulfur acid sodium crystal in the second crystallization dress It sets the second crystallization of middle progress and obtains the magma of sulfur acid sodium crystal.At this point, the evaporation conditions of second evaporation need to meet Make sulfate crystal in second crystallization process and purpose that sodium chloride is not precipitated.Second crystallization apparatus is not special It limits, such as can be brilliant flow container, brilliant liquid collecting tank, with stirring thickener or without stirring thickener etc..It is according to the present invention One preferred embodiment, second crystallization carry out in brilliant liquid collecting tank 55.The condition of second crystallization can fit Work as selection, such as may include：Temperature is 45 DEG C or more；Preferably 85 DEG C~107 DEG C；More preferably 95 DEG C~105 DEG C.In order to Fully ensure that the effect of crystallization, crystallization time can be 5min~for 24 hours, preferably 5min~30min.It is described according to the present invention Second crystallization process of the second concentrate of sulfur acid sodium crystal can also be in vaporising device (such as forced circulation with crystallizer Crystallizing evaporator) in carry out, at this time second crystallization temperature be it is corresponding second evaporation temperature.

According to the present invention, when carrying out the second crystallization using individual crystallization apparatus, need to be further ensured that described second steams Hair is not so that sodium chloride crystallizes precipitation in the second crystallization process (i.e. sodium chloride is not up to supersaturation), it is preferable that described second Evaporation makes a concentration of X or less (the preferably 0.9X-0.99X, more preferably 0.95X- of sodium chloride in second concentrate 0.999X, further preferably 0.99X-0.9967X), wherein X is under conditions of second crystallization, in the second concentrate The concentration of sodium chloride when sodium chloride and sodium sulphate reach saturation.

According to the present invention, second steam containing ammonia and the first mother liquor are subjected to the second heat exchange and obtain the second ammonium hydroxide. Preferably, the second steam containing ammonia carries out the second heat exchange with the first mother liquor, pending waste water successively and obtains the second ammonium hydroxide.It is described There is no particular limitation for the mode of second heat exchange, and the heat exchange mode that this field routine may be used carries out.The heat exchange Number can be 1 time or more, preferably 2-4 times, more preferably 2-3 times.By the heat exchange, the ammonium hydroxide of output is cooled, Heat utmostly recycles inside processing unit, and the energy is rationally utilized, and reduces waste.

A preferred embodiment according to the present invention, second heat exchange pass through third heat-exchanger rig 33 and the 4th Heat-exchanger rig 34 carries out, and specifically, the second steam containing ammonia is passed sequentially through the 4th heat-exchanger rig 34 and third heat-exchanger rig 33, The second heat exchange is carried out with the mixing liquid of the first mother liquor, second circulation liquid and the second leacheate in 4th heat-exchanger rig 34, The second heat exchange is carried out with the first mother liquor in third heat-exchanger rig 33, preferably further carries out first in the 5th heat-exchanger rig 35 Heat exchange, further decreases the temperature of the second steam condensate containing ammonia, improves heat utilization rate, obtains the second ammonium hydroxide, and described the Two ammonium hydroxide are stored in the second tank used for storing ammonia 52.

Preferably, after carrying out the second heat exchange by the third heat-exchanger rig 33, the temperature of first mother liquor is 59 DEG C~364 DEG C, more preferably 69 DEG C~129 DEG C；Preferably, after carrying out the second heat exchange by the 4th heat-exchanger rig 34, The temperature of first mother liquor is 67 DEG C~370 DEG C, more preferably 75 DEG C~137 DEG C.

In the present invention, sodium sulphate is made not crystallize precipitation in order to reach first evaporation, second evaporation makes chlorination Sodium does not crystallize the purpose of precipitation, preferably makes twice evaporation (being corresponding crystallization condition when being crystallized using individual crystallization apparatus) Condition meet：The temperature of first evaporation is 5 DEG C at least lower than the temperature of the second evaporation, 20 DEG C preferably low, and more preferably low 35 DEG C~70 DEG C, particularly preferably low 40 DEG C~60 DEG C.It is carried out, is made at different temperature by the first evaporation of control and the second evaporation The crystallization respectively of sodium chloride and sodium sulphate is precipitated, to improve the purity of obtained sodium chloride and sodium sulfate crystal.

In the present invention, the second concentrate of the sulfur acid sodium crystal obtains sodium sulphate crystalline substance after second is separated by solid-liquid separation Body and the second mother liquor (namely second is separated by solid-liquid separation obtained liquid phase), the second mother liquor is temporarily stored into the second mother liquor tank 54.It is described There is no particular limitation for second method being separated by solid-liquid separation, 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 8th circulating pump 78 Second of pH value adjustment process is mixed to get the pending waste water with the ammonium salt-containing waste water, is then fed into the first evaporation dress The first evaporation is carried out in setting 2.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, which preferably carries out in the device well known in the art such as settling tank, settling tank).It eluriated Cheng Zhong, relative to the slurries of 1 parts by weight sulfur acid sodium crystal, it is 1~20 parts by weight to eluriate the liquid used.In addition, elution is excellent Using aqueous sodium persulfate solution, (concentration of the aqueous sodium persulfate solution is preferably sulphur at the temperature corresponding to sodium sulfate crystal to be washed for choosing Sour sodium and sodium chloride reach the concentration of sodium sulphate in the aqueous solution of saturation simultaneously) it carries out.In order to further increase the effect of elutriation, The higher sodium sulfate crystal of purity is obtained, in the case of preferred, the liquid that elution obtains can be used to carry out above-mentioned elutriation.For Wash the liquid generated, it is preferable that the ammonium salt-containing waste water eluriates second of pH that liquid is back to before the evaporation of the first vaporising device Before value is adjusted, other cleaning solutions are back to the second vaporising device, such as return to the second evaporation by the 9th circulating pump 79 in Fig. 1 Device 1 carries out the second evaporation again.

A preferred embodiment according to the present invention, by the of the sulfur acid sodium crystal that the second evaporative crystallization obtains Two concentrates carry out first time elutriation with the ammonium salt-containing waste water after settling progress tentatively separation of solid and liquid in eluriating tank, Then it reuses the liquid obtained when subsequent wash sodium sulfate crystal and carries out second of elutriation in another elutriation tank, finally will Equipment for separating liquid from solid is sent by the slurries eluriated twice to be separated by solid-liquid separation, the crystal being separated by solid-liquid separation uses sodium sulphate water again (sodium sulphate and sodium chloride reach solution simultaneously at a concentration of temperature corresponding to sodium sulfate crystal to be washed of the aqueous sodium persulfate solution To the concentration of sodium sulphate in the aqueous solution of saturation) it is eluted, and make during the liquid that elution obtains is eluriated back to second To eluriate liquid.The purity of the washing process combined by above-mentioned elutriation and elution, the sodium sulfate crystal not only made improves, and 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, hereinafter also referred to as circulation fluid) it flows back into MVR vaporising devices after heating and carries out again Evaporation.It is not limited particularly as the ratio that the partially liq after the evaporation of MVR vaporising devices is flowed back into MVR vaporising devices System, for example, the first reflux ratio of first evaporation can be 10-200, preferably 40-120, the second of second evaporation Reflux ratio can be 0.1-50, preferably 2-15.Here, reflux ratio refers to：Regurgitant volume and the liquid being sent into MVR vaporising devices Total amount subtracts the ratio of regurgitant volume.Preferably, the first circulation liquid in the first evaporation is preferably returned to second of pH value adjusting Before, the first circulation liquid is exchanged heat back to the first heat-exchanger rig 31 and second for example, 72 can be pumped by second circulation It is mixed with pending waste water in waste water conveyance conduit between device 32, then after being adjusted by second of pH value, Heat exchange is carried out in the second heat-exchanger rig 32, is finally sent into first vaporising device 2.

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 It coagulates remaining tail gas and second steam containing ammonia and condenses remaining tail gas by removing ammonia heel row by second heat exchange It puts.As shown in Figure 1, first steam containing ammonia condenses remaining tail gas, that is, the second heat exchange dress by first heat exchange The tail gas of 32 discharges is set, second steam containing ammonia condenses remaining i.e. the 4th heat-exchanger rig of tail gas by second heat exchange The tail gas of 34 discharges.By by above-mentioned tail gas remove ammonia, the pollutant load in emission can be further decreased so that it can 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.As the ammonium salt-containing waste water of the present invention, specifically may be used Think the waste water from molecular sieve, aluminium oxide or oil refining catalyst production process, can also be by from molecular sieve, aluminium oxide or The waste water of oil refining catalyst production process carries out the waste water after following removal of impurities and concentration.Molecular sieve, aluminium oxide will preferably be come from Or the waste water of 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 1000mg/L or more, more preferably For 2000mg/L or more, further preferably 4000mg/L or more, further preferably 8000mg/L or more, further preferably 16000mg/L or more, further preferably 32000mg/L or more, further preferably 40000mg/L or more, further preferably For 50000mg/L or more, further preferably 60000mg/L or more.

As the SO in the ammonium salt-containing waste water₄ ^2-Can be 1000mg/L or more, preferably 2000mg/L or more, it is more excellent It is selected as 4000mg/L or more, further preferably 8000mg/L or more, further preferably 16000mg/L or more, it is further excellent It is selected as 32000mg/L or more, further preferably 40000mg/L or more, further preferably 50000mg/L or more, further Preferably 60000mg/L or more, further preferably 70000mg/L or more.

As the Cl in the ammonium salt-containing waste water^-Can be 970mg/L or more, more preferably 2000mg/L or more, into one Step is preferably 4000mg/L or more, further preferably 8000mg/L or more, further preferably 16000mg/L or more, into one Step preferably 32000mg/L or more, further preferably 40000mg/L or more, further preferably 50000mg/L or more, into One step is preferably 60000mg/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 waste water₄ ^2-、Cl^-And Na⁺The upper limit be respectively 200g/L hereinafter, preferably 150g/L or less；It is useless NH in water₄ ⁺For 50g/L hereinafter, preferably 20g/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, further preferably following 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 sulfate crystal and sodium chloride 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 1600mg/L or more, preferably 4000mg/L or more, more preferably 8000mg/L or more, further preferably 16000mg/L or more, further preferably 32000mg/L or more, further preferably 40000mg/L or more, further preferably 50000mg/L or more, further preferably 60000mg/L or more, further preferably For 100000mg/L or more, further preferably 150000mg/L or more, further preferably 200000mg/L or more.

In the present invention, the pH value of the ammonium salt-containing waste water is preferably 4~8, and more preferably pH is 6.4~6.6.

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 waste water, ensure that the continuous-stable of processing procedure carries out, drop Low equipment operation maintenance cost, the ammonium salt-containing waste water using the processing method of the present invention before being handled preferably through removal of impurities.It is excellent Selection of land, the removal of impurities are 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 ammonium salt-containing 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 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 described be concentrated by the concentration of ED films and reverse osmosis progress, institute Stating the concentration of ED films and the sequencing of reverse osmosis progress, there is no particular limitation.ED films concentration and reverse osmosis treatment device and The mode that this field routine may be used in condition carries out, and can be specifically chosen according to the case where pending waste water.Specifically, as The ED films concentration, can select unidirectional electrodialysis system or pole-reversing electroosmosis system to carry out；As described reverse osmosis, Ke Yixuan It is carried out with rolled film, plate membrane, dish tubular membrane, vibrating membrane or combinations thereof.It can be improved at ammonium salt-containing waste water by the concentration The efficiency of reason avoids energy waste caused by largely evaporating.

In the preferred embodiment of the present invention, ammonium salt-containing waste water is that the waste water in process of producing molecular sieve passes through Chemical precipitation, filtering, Subacidity cation exchange process and ozone biological activated carbon adsorption and oxidation method clean, and pass through ED films Waste water after concentration and 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 are added in ion, and the pH for adjusting waste water is more than 7, and reaction temperature is 20 DEG C~35 DEG C, and the reaction time is 0.5h~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 0.7mm~1.7mm, and quartz sand particle size is 0.5mm~1.3mm, filtering velocity 10m/h ~30m/h.Media regeneration is carried out using the regeneration method of " gas backwash-gas and water backwash-water backwashing " after filtrate use, Regeneration period 10h~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 1.5m~3.0m, regenerated liquid HCl concentration：4.5~5 mass %；Regenerant consumption (based on 100%), 50kg/ m³~60kg/m³Wet resin；Regenerated liquid HCl flow velocitys are 4.5m/h~5.5m/h, and regeneration time of contact is 35min~45min；Just It is 18m/h~22m/h to wash flow velocity, and it is 20min~30min just to wash the time；Operation flow velocity is 15m/h~30m/h；Acid cation Langfang sanat Chemical Co., Ltd., SNT board D113 acid cation exchange resins can be used for example in exchanger resin.

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

As above-mentioned ED films concentration condition be preferably：Electric current 145A~155A, voltage 45V~65V.For example as ED films Can be the ED films of A Sitong companies of Japan production.

It is preferably as above-mentioned reverse osmosis condition：Operating pressure 5.4MPa~5.6MPa, 25 DEG C~35 DEG C of inflow temperature, PH value is 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, the first evaporation can be first carried out with condition according to the invention and carry out the second steaming again Hair；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 in the first concentrate Then first concentrate is carried out the second evaporation by the concentration of sodium sulphate close to concentration is precipitated, obtain the second concentrate and solid-liquid point It is mixed with the ammonium salt-containing waste water to adjust pending waste water from obtaining sodium sulfate crystal and the second mother liquor, then by the second mother liquor Ion concentration obtains sodium chloride crystal to carry out the first evaporation again after range of the presently claimed invention.Certainly also may be used in the starting stage To use Na₂SO₄Or the ion concentration in pending waste water is adjusted in NaCl, as long as the pending waste water is made to meet this To SO in pending waste water in invention₄ ^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 (160g/L containing NaCl, Na₂SO₄ 50g/L、NH₄Cl 39g/L、(NH₄)₂SO₄ 12.4g/L, pH 6.5) with inlet amount it is 5m³The speed of/h is sent into vacuum receiver 4 and carries out vacuum outgas, imports in the duct The sodium hydrate aqueous solution of a concentration of 45.16 mass % carries out first time pH value adjusting, and passes through the first pH value measuring device 61 (pH meter) is monitored (measured value 7.5) to the pH value after adjusting, and will pass through the first pH value by first circulation pump 71 is adjusted A part (the 1m of ammonium salt-containing waste water afterwards³/ h) it is sent into the second of the 5th heat-exchanger rig 35 (titanium alloy plate heat exchanger) and recycling The liquid of steam condensation containing ammonia, which carries out the first heat exchange, makes ammonium salt-containing waste water be warming up to 48 DEG C, and rest part is sent into the first heat-exchanger rig 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 49 DEG C；Then, by two parts Ammonium salt-containing waste water converges, and is mixed to get pending waste water with the second mother liquor and (measures the SO wherein contained₄ ^2-And Cl^-Molar ratio It is 1：12.656) pending waste water, is being sent into the pipeline of the second heat-exchanger rig 32 to the hydrogen for importing a concentration of 45.16 mass % Aqueous solution of sodium oxide carry out second of pH value adjusting, and by the second pH value measuring device 62 (pH meter) to the pH value after adjusting into Row monitoring (measured value 11), be then fed into the second heat-exchanger rig 32 (titanium alloy plate heat exchanger) and recycling first are steamed containing ammonia Vapour, which carries out the first heat exchange, makes pending waste water be warming up to 57 DEG C, then pending waste water is being sent into 2 (falling liquid film of the first vaporising device + forced circulation two-stage MVR crystallizing evaporators) it is evaporated, obtain the first concentration of the first steam containing ammonia and sodium chloride-containing crystal Liquid.Wherein, the evaporating temperature of the first vaporising device 2 is 50 DEG C, and pressure is -92.7kPa, evaporation capacity 4.56m³/h.It evaporates To the first steam containing ammonia by the first compressor 101 compression after (10 DEG C of temperature rise) pass sequentially through 32 He of the second heat-exchanger rig First heat-exchanger rig 31 carries out heat exchange with pending waste water and ammonium salt-containing waste water respectively, and cooling obtains the first ammonium hydroxide, and stores In the first tank used for storing ammonia 51.In addition, in order to improve the solid content in the first vaporising device 2, will be steamed in the first vaporising device 2 Partially liq after hair is recycled to the second heat-exchanger rig 32 as first circulation liquid by second circulation pump 72, is then again introduced into First vaporising device 2 carries out the first evaporation (the first reflux ratio is 95.4).Pass through the densitometer pair being arranged on the first vaporising device 2 The degree of first evaporation is monitored, and controls a concentration of 0.9705Y (65.7g/L) of sodium sulphate in the first concentrate.

After first concentrate is sent into the first separation of solid and liquid of the first equipment for separating liquid from solid 91 (centrifuge) progress, per hour To 20.87m³Contain NaCl 294.6g/L, Na₂SO₄ 65.7g/L、NaOH 0.22g/L、NH₃The first mother liquor of 0.11g/L, It is temporarily stored into the first mother liquor tank 53, is separated by solid-liquid separation gained solid sodium chloride and (obtains the sodium chloride knot of aqueous 15 mass % per hour Brilliant filter cake 1196.17kg, the wherein content of sodium sulphate be 3.9 mass % or less) with sodium chloride crystalli-zation cake butt quality phase Deng the elution of 295g/L sodium chloride solutions, sodium chloride 1016.74kg (purity is 99.5 weight %) is obtained after dry per hour, is washed It washs liquid and is recycled to before second pH value is adjusted by the 5th circulating pump 75 and mixed with pending waste water, be then again introduced into the One vaporising device 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.So that the first mother liquor in above-mentioned first mother liquor tank 53 is passed through third heat-exchanger rig 33 and second by the 6th circulating pump 76 and contains ammonia Steam condensation liquid carries out heat exchange, then by the 4th heat-exchanger rig 34 and the progress heat exchange of the second steam containing ammonia, is finally sent into the Two vaporising devices 1 carry out the second evaporation and obtain the second concentrate of the second steam containing ammonia and sulfur acid sodium crystal.Wherein, second steams The evaporating temperature of transmitting apparatus 1 is 105 DEG C, and pressure is -7.0kPa, evaporation capacity 1.05m³/h.In order to improve the second vaporising device 1 In solid content, using in the second vaporising device 1 evaporate after the first mother liquor of part as second circulation liquid pass through the 7th recycle Pump 77 is recycled to the 4th heat-exchanger rig 34, is then again introduced into the second vaporising device 1 and carries out the second evaporation (the second reflux ratio is 4).The second steam containing ammonia that evaporation obtains (12 DEG C of temperature rise) after the compression of the second compressor 102 passes sequentially through the 4th and changes Thermal 34, third heat-exchanger rig 33 and the first mother liquor carry out the second heat exchange, then by the 5th heat-exchanger rig 35 with and the The part ammonium salt-containing waste water of one circulating pump 71 conveying carries out the first heat exchange, and cooling obtains the second ammonium hydroxide, and is stored in the second ammonia In water storage tank 52.The degree evaporated by the densitometer pair second being arranged on the second vaporising device 1 is monitored, and control second is dense A concentration of 0.99355X (307.9g/L) of sodium chloride in contracting liquid.After first mother liquor evaporates in the second vaporising device 1, contained There is the second concentrate of sodium sulfate crystal.

The second concentrate containing sodium sulfate crystal is sent into the second equipment for separating liquid from solid 92 (centrifuge) and is separated by solid-liquid separation, 20.21m is obtained per hour³Contain NaCl 307.9g/L, Na₂SO₄ 53.0g/L、NaOH 0.30g/L、NH₃0.0035g/L's Second mother liquor, the second mother liquor are temporarily stored into the second mother liquor tank 54.Second mother liquor is all recycled to by the 8th circulating pump 78 Before second of pH value is adjusted, pending waste water is mixed to get with the ammonium salt-containing waste water after preheating.It is solid to be separated by solid-liquid separation gained sodium sulphate Body (obtains the sulfate crystal filter cake 364.15kg that water content is 14 mass %, the wherein content of sodium chloride is 3.8 matter per hour Measure % or less) with after the 53g/L metabisulfite solutions elution equal with sodium sulphate butt quality, it is dried in drying machine, per hour Sodium sulphate 313.17kg (purity is 99.5 weight %) is obtained, the second cleaning solution washed is recycled by the 9th circulating pump 79 To the second vaporising device 1.

In addition, the tail gas of vacuum receiver 4, the second heat-exchanger rig 32 and the discharge of the 4th heat-exchanger rig 34 passes through vacuum pump 81 It introduces tail gas absorber 83 to be absorbed, recirculated water is connected in tail gas absorber 83, the recirculated water is in the 4th circulating pump 74 It recycles in tail gas absorber 83 under effect, while being mended to tail gas absorber 83 from circulating water pool 82 by third circulating pump 73 Add water, and add fresh water in circulating water pool 82, reduces by the temperature and ammonia content of 81 work water of vacuum pump.The tail gas It is further passed through dilute sulfuric acid in absorption tower 83, to absorb ammonia in tail gas etc..

In the present embodiment, the ammonium hydroxide 4.56m of a concentration of 1.63 mass % is obtained in the first tank used for storing ammonia 51 per hour³, The ammonium hydroxide 1.05m of a concentration of 0.21 mass % is obtained in second tank used for storing ammonia 52 per hour³, ammonium hydroxide can be back to the life of molecular sieve Production process.

In addition, the initial period of MVR evaporations, the steam for being 143.3 DEG C by temperature are started.

Embodiment 2

The processing of ammonium salt-containing waste water is carried out according to the method for embodiment 1, unlike：To containing NaCl 60g/L, Na₂SO₄ 130g/L、NH₄Cl 15g/L、(NH₄)₂SO₄The ammonium salt-containing waste water that 33.04g/L, pH are 6.6 is handled, and what is obtained is pending The SO contained in waste water₄ ^2-And Cl^-Molar ratio be 1：11.496.Pass through ammonium salt-containing after the progress heat exchange of the 5th heat-exchanger rig 35 The temperature of waste water is 53 DEG C, and the temperature that ammonium salt-containing waste water after heat exchange is carried out by the first heat-exchanger rig 31 is 54 DEG C, by the The temperature of pending waste water is 62 DEG C after the progress heat exchange of two heat-exchanger rigs 32.The evaporating temperature of first vaporising device 2 is 55 DEG C, Pressure is -90.2kPa, evaporation capacity 2.76m³/h.The evaporating temperature of second vaporising device 1 is 95 DEG C, and pressure is -36.4kPa, Evaporation capacity is 2.93m³/h。

First equipment for separating liquid from solid 91 obtains the sodium chloride crystalli-zation cake 445.34kg of aqueous 15 mass % per hour, finally Obtain sodium chloride 378.54kg per hour (purity is 99.6 weight %)；82.63m is obtained per hour³A concentration of NaCl 296.6g/L、Na₂SO₄ 63.6g/L、NaOH 0.29g/L、NH₃The first mother liquor of 0.032g/L.

Second equipment for separating liquid from solid 92 obtains the sulfate crystal filter cake 977.85kg that water content is 15 mass % per hour, It is final to obtain sodium sulphate 831.17kg per hour (purity is 99.4 weight %)；80.07m is obtained per hour³, a concentration of NaCl 306.1g/L、Na₂SO₄ 55.3g/L、NaOH 0.3g/L、NH₃The second mother liquor of 0.0013g/L.

In the present embodiment, the ammonium hydroxide 2.76m of a concentration of 2.26 mass % is obtained in the first tank used for storing ammonia 51 per hour³, The ammonium hydroxide 2.93m of a concentration of 0.087 mass % is obtained in second tank used for storing ammonia 52 per hour³, ammonium hydroxide can be back to molecular sieve Production 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 81g/L, Na₂SO₄ 79g/L、NH₄Cl 32g/L、(NH₄)₂SO₄The ammonium salt-containing waste water that 31.72g/L, pH are 6.4 is handled, and what is obtained is pending The SO contained in waste water₄ ^2-And Cl^-Molar ratio be 1：11.123.Pass through ammonium salt-containing after the progress heat exchange of the 5th heat-exchanger rig 35 The temperature of waste water is 43 DEG C, and the temperature that ammonium salt-containing waste water after heat exchange is carried out by the first heat-exchanger rig 31 is 44 DEG C, by the The temperature of pending waste water is 52 DEG C after the progress heat exchange of two heat-exchanger rigs 32.The evaporating temperature of first vaporising device 2 is 45 DEG C, Pressure is -94.7kPa, evaporation capacity 3.73m³/h.The evaporating temperature of second vaporising device 1 be 100 DEG C, pressure be- 22.9kPa, evaporation capacity 1.99m³/h。

First equipment for separating liquid from solid 91 obtains the sodium chloride crystalli-zation cake 675.13kg of aqueous 14 mass % per hour, finally Obtain sodium chloride 580.61kg per hour (purity is 99.4 weight %)；36.26m is obtained per hour³A concentration of NaCl 292.4g/L、Na₂SO₄ 67.3g/L、NaOH 0.1g/L、NH₃The first mother liquor of 0.076g/L.

Second equipment for separating liquid from solid 92 obtains the sulfate crystal filter cake 657.0kg that water content is 14 mass % per hour, It is final to obtain sodium sulphate 580.6kg per hour (purity is 99.5 weight %)；34.52m is obtained per hour³, a concentration of NaCl 307.1g/L、Na₂SO₄ 54.3g/L、NaOH 0.105g/L、NH₃The second mother liquor of 0.0039g/L.

In the present embodiment, the ammonium hydroxide 3.73m of a concentration of 2.3 mass % is obtained in the first tank used for storing ammonia 51 per hour³, the The ammonium hydroxide 1.99m 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 4

As shown in Fig. 2, by ammonium salt-containing waste water (156g/L containing NaCl, Na₂SO₄ 49g/L、NH₄Cl 62g/L、(NH₄)₂SO₄ 19.8g/L, pH 6.7) by first circulation pump 71 with inlet amount it is 5m³The speed of/h is sent in the pipeline of processing system, The sodium hydrate aqueous solution that a concentration of 45.16 mass % is imported into pipeline carries out first time pH value adjusting, passes through the first pH value Measuring device 61 (pH meter) is monitored (measured value 7.4) to the pH value after adjusting, will be after the adjusting of first time pH value An ammonium salt-containing waste water part (3m³/ h) it is sent into the first steam containing ammonia of the first heat-exchanger rig 31 (plastics plate heat exchanger) and recycling Condensation water, which carries out heat exchange, makes ammonium salt-containing waste water be warming up to 54 DEG C, and rest part is sent into 34 (two phase stainless steel of the 4th heat-exchanger rig Plate heat exchanger) with recycling the second liquid of steam condensation containing ammonia progress heat exchange so that ammonium salt-containing waste water is warming up to 70 DEG C, next Two parts ammonium salt-containing waste water is merged, and is mixed to get pending waste water with the second mother liquor and (measures the SO wherein contained₄ ^2-And Cl^- Molar ratio be 1：12.444) pending waste water, then, is sent into the second heat-exchanger rig 32 (titanium alloy plate heat exchanger), with First steam containing ammonia of recycling, which carries out the first heat exchange, makes pending waste water be warming up to 62 DEG C, then is handed over that will pass through the first heat twice Pending waste water after changing is sent to the sodium hydroxide water that a concentration of 45.16 mass % is imported in the pipeline of the first vaporising device 2 Solution carries out second of pH value adjusting, and is monitored to the pH value after adjusting by the second pH value measuring device 62 (pH meter) (measured value 10.8), the pending waste water after the adjusting of the second pH value is sent into the first vaporising device 2, and (falling liquid film+pressure follows Ring two-stage MVR crystallizing evaporators) it is evaporated, obtain the first concentrate of the first steam containing ammonia and sodium chloride-containing crystal.Wherein, The evaporating temperature of first vaporising device 2 is 55 DEG C, and pressure is -90.2Pa, evaporation capacity 4.63m³/h.First obtained is evaporated to contain Ammonia steam (10 DEG C of temperature rise) after the compression of the first compressor 101 passes sequentially through the second heat-exchanger rig 32 and first heat exchange dress 31 are set, carries out heat exchange with pending waste water and ammonium salt-containing waste water respectively, cooling obtains the first ammonium hydroxide, and is stored in the first ammonium hydroxide In storage tank 51.In addition, in order to improve the solid content in the first vaporising device 2, by the part after being evaporated in the first vaporising device 2 Liquid is back to the second heat-exchanger rig 32 as circulation fluid by second circulation pump 72, is then again introduced into the first vaporising device 2 Carry out the first evaporation (reflux ratio 96.4).The degree evaporated by the densitometer pair first that is arranged on the first vaporising device 2 into Row monitoring, controls a concentration of 0.9707Y (66.25g/L) of sodium sulphate in the first concentrate.

By obtained the first concentrate of above-mentioned first vaporising device 2 evaporation enter the first equipment for separating liquid from solid 91 (centrifuge) into After row first is separated by solid-liquid separation, 24.13m is obtained per hour³Contain NaCl 293.8g/L, Na₂SO₄ 66.25g/L、NaOH 0.18g/L、NH₃The first mother liquor of 0.10g/L is temporarily stored into the first mother liquor tank 53, and it is (every to be separated by solid-liquid separation gained solid sodium chloride Hour obtains the sodium chloride crystalli-zation cake 1306.96kg of aqueous 14 mass %, the wherein content of sodium sulphate be 3.9 mass % with Under) eluted with the 293g/L sodium chloride solution equal with sodium chloride crystalli-zation cake butt quality, chlorination is obtained per hour after dry Sodium 1124kg (purity is 99.4 weight %), cleaning solution is recycled to the second heat-exchanger rig 32 by the 8th circulating pump 78, then again Secondary first vaporising device 2 that enters carries out the first evaporation.

Second evaporation process carries out in the second vaporising device (multi-effect evaporating device) 1, second vaporising device 1 It is made of 1st effective evaporator 1a, 2nd effect evaporator 1b and third effect evaporator 1c (being forced-circulation evaporator).Pass through The first mother liquor in above-mentioned mother liquor tank 54 is sent into the second vaporising device 1 by the 5th circulating pump 75, and the first mother liquor is in the first effect evaporation After being evaporated in device 1a, it is passed through in 2nd effect evaporator 1b and evaporates, then be passed through in third effect evaporator 1c and evaporate, it is finally obtained to contain Second concentrate of sodium sulfate crystal.Wherein, the evaporating temperature of 1st effective evaporator 1a is 128 DEG C, pressure 103.53kPa, Evaporation capacity is 0.41m³/h；The evaporating temperature of 2nd effect evaporator 1b is 114 DEG C, pressure 28.07kPa, and evaporation capacity is 0.40m³/h；The evaporating temperature of third effect evaporator 1c is 100 DEG C, and pressure is -22.83kPa, evaporation capacity 0.40m³/h.By institute It states the second steam containing ammonia evaporated in the 1st effective evaporator 1a of the second vaporising device 1 and is passed through 2nd effect evaporator 1b progress Second heat exchange simultaneously obtains the first ammonium hydroxide, and the second steam containing ammonia evaporated in 2nd effect evaporator 1b, which is passed through third effect, to be steamed Hair device 1c carries out the second heat exchange and obtains the first ammonium hydroxide, the ammonium hydroxide obtained from 2nd effect evaporator 1b, 1st effective evaporator 1c By being stored in the second tank used for storing ammonia 52 after the 4th heat-exchanger rig 34 and ammonium salt-containing wastewater heat exchange.In 1st effective evaporator 1a It is passed through heating steam (life steam i.e. commonly used in the art), what heating steam obtained after being condensed in 1st effective evaporator 1a Condensation water, condensation water is used to preheat into after the pending waste water (raw material) of the first vaporising device 2, molten for preparing washing Liquid.The second steam containing ammonia that the third effect evaporator 1c of second vaporising device 1 evaporates in third heat-exchanger rig 33 with it is cold But water (ammonium salt-containing waste water) carries out heat exchange and obtains the second ammonium hydroxide, and is stored in the second tank used for storing ammonia 52.It is steamed by second The degree that the densitometer pair second being arranged on transmitting apparatus 1 evaporates is monitored, and sodium chloride is a concentration of in the second concentrate of control 0.99353X(307.1g/L).After first mother liquor evaporates in the second vaporising device 1, the of finally obtained sulfur acid sodium crystal Two concentrates crystallize (crystallization temperature is 100 DEG C, crystallization time 10min) in brilliant liquid collecting tank 55 and obtain sulfur acid sodium crystal Magma.

The magma of sulfur acid sodium crystal is sent into the second equipment for separating liquid from solid 92 (centrifuge) and is separated by solid-liquid separation, per hour To 20.13m³Contain NaCl 307.1g/L, Na₂SO₄ 54.2g/L、NaOH 0.19g/L、NH₃The second of 0.0053g/L is female Second mother liquor is recycled to waste water import pipe by the 7th circulating pump 77 and is mixed to get pending give up with ammonium salt-containing waste water by liquid Water, separation of solid and liquid gained solid sodium sulfate (the sulfate crystal filter cake 407.7kg that water content is 15 mass % is obtained per hour, Wherein the content of sodium chloride is 4 mass % or less) with after equal with sodium sulphate butt quality 54g/L metabisulfite solutions elution, It is dry in drying machine, sodium sulphate 346.54kg (purity is 99.5 weight %), the second washing washed are obtained per hour Liquid is back to the second vaporising device 1 by the 6th circulating pump 76.

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 the present embodiment, the ammonium hydroxide 4.63m of a concentration of 2.56 mass % is obtained in the first tank used for storing ammonia 51 per hour³, The ammonium hydroxide 1.21m of a concentration of 0.19 mass % is obtained in second tank used for storing ammonia 52 per hour³, ammonium hydroxide can be back to the life of molecular sieve Production 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 160g/L, Na₂SO₄ 25g/L、NH₄Cl 39g/L、(NH₄)₂SO₄The ammonium salt-containing waste water that 6.2g/L, pH are 6.5 is handled, and is filled by the first heat exchange The temperature for setting ammonium salt-containing waste water after 31 carry out heat exchanges is 44 DEG C, and ammonium salt-containing is useless after carrying out heat exchange by the 4th heat-exchanger rig 34 The temperature of water is 100 DEG C, and the temperature by pending waste water after the progress heat exchange of the second heat-exchanger rig 32 is 52 DEG C, and what is obtained waits for The SO contained in processing waste water₄ ^2-And Cl^-Molar ratio be 1：14.438.The evaporating temperature of first vaporising device 2 is 45 DEG C, pressure Power is -94.69kPa, evaporation capacity 4.94m³/h.The evaporating temperature of the 1st effective evaporator 1a of second vaporising device 1 is 130 DEG C, pressure 116.77kPa, evaporation capacity 0.19m³/h；The evaporating temperature of 2nd effect evaporator 1b is 117 DEG C, and pressure is 41.92kPa, evaporation capacity 0.19m³/h；The evaporating temperature of third effect evaporator 1c is 105 DEG C, and pressure is -7.02kPa, evaporation Amount is 0.18m³/h。

First equipment for separating liquid from solid 91 obtains the sodium chloride crystalli-zation cake 1198.31kg of aqueous 15 mass % per hour, most Obtain sodium chloride 1018.57kg per hour eventually (purity is 99.4 weight %)；9.49m is obtained per hour³A concentration of NaCl 291.8g/L、Na₂SO₄ 67g/L、NaOH 0.16g/L、NH₃The first mother liquor of 0.07g/L.

Second equipment for separating liquid from solid 92 obtains the sulfate crystal filter cake 177.95kg that water content is 14 mass % per hour, It is final to obtain sodium sulphate 153.04kg per hour (purity is 99.5 weight %)；9.00m is obtained per hour³A concentration of NaCl 307.9g/L、Na₂SO₄ 53.1g/L、NaOH 0.17g/L、NH₃The second mother liquor of 0.0031g/L.

In the present embodiment, the ammonium hydroxide 4.94m of a concentration of 1.38 mass % is obtained in the first tank used for storing ammonia 51 per hour³, The ammonium hydroxide 0.56m of a concentration of 0.118 mass % is obtained in second tank used for storing ammonia 52 per hour³。

Embodiment 6

The processing of ammonium salt-containing waste water is carried out according to the method for embodiment 4, unlike：To containing NaCl 105g/L, Na₂SO₄ 108g/L、NH₄Cl 20g/L、(NH₄)₂SO₄The ammonium salt-containing waste water that 20.91g/L, pH are 6.7 is handled, ammonium salt-containing waste water A part (2.5m³/ h) by the first heat-exchanger rig 31 carry out heat exchange after temperature be 49 DEG C, rest part is changed by the 4th It is 85 DEG C that thermal 34, which carries out the temperature after heat exchange, and pending waste water carries out the temperature after heat exchange by the second heat-exchanger rig 32 Degree is 57 DEG C, the SO contained in obtained pending waste water₄ ^2-And Cl^-Molar ratio be 1：11.333.First vaporising device 2 Evaporating temperature is 50 DEG C, and pressure is -92.7kPa, evaporation capacity 3.35m³/h.The 1st effective evaporator 1a of second vaporising device 1 Evaporating temperature be 125 DEG C, pressure 84.91kPa, evaporation capacity 0.77m³/h；The evaporating temperature of 2nd effect evaporator 1b is 110 DEG C, pressure 11.34kPa, evaporation capacity 0.75m³/h；The evaporating temperature of third effect evaporator 1c be 95 DEG C, pressure be- 36.37kPa, evaporation capacity 0.75m³/h。

First equipment for separating liquid from solid 91 obtains the sodium chloride crystalli-zation cake 745.41kg of aqueous 15 mass % per hour, finally Obtain sodium chloride 633.59kg per hour (purity is 99.5 weight %)；52.06m is obtained per hour³A concentration of NaCl 294.6g/L、Na₂SO₄ 65.7g/L、NaOH 0.22g/L、NH₃The first mother liquor of 0.056g/L.

Second equipment for separating liquid from solid 92 obtains the sulfate crystal filter cake 768.53kg that water content is 15 mass % per hour, It is final to obtain sodium sulphate 653.25kg per hour (purity is 99.4 weight %)；50.07m is obtained per hour³A concentration of NaCl 306.2g/L、Na₂SO₄ 55.3g/L、NaOH 0.229g/L、NH₃The second mother liquor of 0.0017g/L.

In the present embodiment, the ammonium hydroxide 3.35m of a concentration of 1.63 mass % is obtained in the first tank used for storing ammonia 51 per hour³, The ammonium hydroxide 2.27m of a concentration of 0.12 mass % is obtained in second tank used for storing ammonia 52 per hour³。

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 and obtains the first concentrate of the first steam containing ammonia and sodium chloride-containing crystal, it is described Pending waste water contains the ammonium salt-containing waste water；

2) the first concentrate 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 It mutually carries out the second evaporation 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；

First evaporation makes sodium sulphate not crystallize precipitation, and second evaporation makes sodium chloride 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^-For 9.5 moles with On.

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^-It is 10 Mole 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^-For 10-15 moles；

Preferably, before the pending waste water is passed through the first vaporising device, the pH value for adjusting the pending waste water is big In 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 first evaporation makes the concentration of sodium sulphate in the first concentrate For Y or less, wherein Y is sulfuric acid when sodium chloride and sodium sulphate reach saturation in the first concentrate under conditions of first evaporates The concentration of sodium；

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 the second concentrate；

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

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 30 DEG C~85 DEG C, pressure is -98kPa~-58kPa；

Preferably, temperature is 35 DEG C~60 DEG C, and pressure is -97.5kPa~-87kPa；

Preferably, temperature is 40 DEG C~60 DEG C, and pressure is -97kPa~-87kPa.

Preferably, temperature is 45 DEG C~60 DEG C, and pressure is -95kPa~-87kPa；

Preferably, temperature is 45 DEG C~55 DEG C, and pressure is -95kPa~-90kPa.

5. according to the method described in any one of claim 1-3, wherein it is described second evaporation condition include：Temperature is 45 DEG C or more, pressure is -95kPa or more；

Preferably, temperature is 45 DEG C~365 DEG C, and pressure is -95kPa~18110kPa；

Preferably, temperature is 60 DEG C~365 DEG C, and pressure is -87kPa~18110kPa；

Preferably, temperature is 75 DEG C~175 DEG C, and pressure is -73kPa~653kPa；

Preferably, temperature is 80 DEG C~130 DEG C, and pressure is -66kPa~117kPa；

Preferably, temperature is 95 DEG C~105 DEG C, and pressure is -37kPa~-7kPa.

6. method according to claim 4 or 5, wherein the temperature of first evaporation is 5 DEG C lower than the temperature of the second evaporation More than；

Preferably, temperature low 20 DEG C or more of the temperature of first evaporation than the second evaporation；

Preferably, the temperature of first evaporation is 35 DEG C~70 DEG C lower than the temperature of the second evaporation；

Preferably, the temperature of first evaporation is 50 DEG C~59 DEG C lower than the temperature of the second evaporation.

7. according to the method described in any one of claim 1-6, 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.

8. according to the method described in claim 1, wherein, before carrying out first evaporation, by first steam containing ammonia Or the condensation water of first steam containing ammonia carries out the first heat exchange with the pending waste water and obtains the first ammonium hydroxide；

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

9. according to the method described in any one of claim 1-8, this method further includes by the of the sodium chloride-containing crystal One concentrate obtains sodium chloride crystal after first is separated by solid-liquid separation；

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

10. according to the method described in any one of claim 1-8, 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 obtaining sodium sulfate crystal.

11. according to the method described in any one of claim 1-8, wherein NH in the ammonium salt-containing waste water₄ ⁺For 8mg/L with On, SO₄ ^2-For 1000mg/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.