CN109422313A

CN109422313A - The processing method of catalyst production waste water

Info

Publication number: CN109422313A
Application number: CN201710750767.XA
Authority: CN
Inventors: 殷喜平; 李叶; 顾松园; 王涛; 苑志伟; 刘志坚
Original assignee: China Petroleum and Chemical Corp; Sinopec Catalyst Co
Current assignee: China Petroleum and Chemical Corp; Sinopec Catalyst Co
Priority date: 2017-08-28
Filing date: 2017-08-28
Publication date: 2019-03-05
Anticipated expiration: 2037-08-28
Also published as: CN109422313B

Abstract

The present invention relates to sewage treatment fields, disclose a kind of processing method of catalyst production waste water, which contains NH₄ ⁺、SO₄ ^2‑、Cl^‑And Na⁺, this method includes that waste water to be processed 1) is carried out the first evaporation, obtains the first concentrate of the first steam containing ammonia and sulfur acid sodium crystal, the waste water to be processed contains the catalyst production waste water；2) the first concentrate is carried out first to be separated by solid-liquid separation, and obtained liquid phase is subjected to crystallisation by cooling, obtain the crystal solution of sulfur acid sodium crystal；3) crystal solution is carried out second to be separated by solid-liquid separation, and second is separated by solid-liquid separation obtained liquid phase and carries out the second evaporation, obtain the second concentrate of the second steam containing ammonia and sodium chloride-containing crystal；4) the second concentrate is subjected to cooling processing, obtains the treatment fluid of sodium chloride-containing crystal；5) treatment fluid is subjected to third separation of solid and liquid.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 catalyst production waste water

Technical field

The present invention relates to sewage treatment fields, and in particular, to a kind of processing method of catalyst production waste water, especially It is related to a kind of containing NH₄ ⁺、SO₄ ^2-、Cl^-And Na⁺Catalyst production waste water processing method.

Background technique

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 sulphate and sodium chloride 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 method, blow-off method or vaporizing extract process, then, saline sewage is overregulated into 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 crystallization or multiple-effect evaporation crystallization, obtain the sulphur containing a small amount of ammonium salt Sour sodium and sodium chloride mixing carnallite；Either；First adjust pH value to 6.5-7.5 in the range of, removing most suspended substances, so Afterwards, it except hardness, except silicon and partial organic substances, is 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 crystallization or multiple-effect evaporation, sodium sulphate and the sodium chloride 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 method deamination can only handle the waste water of low ammonium content, and due to COD content 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 method.Sixty-four dollar question is biochemical method deamination treated waste water often total nitrogen (nitre not up to standard Acid ion, nitrite ion content are exceeded), it is also necessary to advanced treating, in addition the content of salt does not reduce (20- in waste water 30g/L), it is unable to direct emission, needs further progress 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 content in water, the salt content in waste water do not reduce (20-30g/L), are unable to direct emission, need Further progress desalting processing, wastewater treatment operating cost is high, remains a large amount of alkali in treated waste water, pH value is very high, wave Fei great, processing cost are up to 50 yuan/ton.

Summary of the invention

The purpose of the invention is to overcome in the prior art containing NH₄ ⁺、SO₄ ^2-、Cl^-And Na⁺Cost for wastewater treatment it is high, And the problem of can only obtain mixing salt crystal, it provides a kind of at low cost and environmentally friendly containing NH₄ ⁺、SO₄ ^2-、Cl^-And Na⁺Catalysis Ammonium and sodium sulphate, sodium chloride in waste water can be separately recovered in agent production waste water processing method, this method, farthest sharp again With the resource in waste water.

To achieve the goals above, one aspect of the present invention provides a kind of processing method of catalyst production waste water, the catalysis Agent production waste water contains NH₄ ⁺、SO₄ ^2-、Cl^-And Na⁺, this approach includes the following steps,

1) waste water to be processed is subjected to the first evaporation, obtains the first concentration of the first steam containing ammonia and sulfur acid sodium crystal Liquid, the waste water to be processed contain the catalyst production waste water；

2) the first concentrate of the sulfur acid sodium 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 crystallisation by cooling, obtain the crystal solution of sulfur acid sodium crystal；

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

4) the second concentrate of the sodium chloride-containing crystal is subjected to cooling processing, obtains the processing of sodium chloride-containing crystal Liquid；

5) treatment fluid is subjected to third separation of solid and liquid；

Wherein, before waste water to be processed is carried out the first evaporation, the pH value for adjusting the waste water to be processed is greater than 9；Phase For the SO contained in waste water to be processed described in 1mol₄ ^2-, the Cl that contains in the waste water to be processed^-For 14mol or less；It is described First evaporation is precipitated sodium chloride crystallization.

Through the above technical solutions, for NH is contained₄ ⁺、SO₄ ^2-、Cl^-And Na⁺Waste water, by advance by waste water to be processed After pH value is adjusted to specific range, carries out the first evaporation and obtain denseer ammonium hydroxide, recycle the isolated sulfuric acid of crystallisation by cooling Then sodium crystal obtains the second concentrate and diluter ammonium hydroxide of sodium chloride-containing crystal and sodium sulfate crystal by the second evaporation, Then cooling processing is recycled to dissolve the sodium sulfate crystal in the second concentrate, sodium chloride further crystallizes precipitation, obtains chlorine Change sodium crystallization.This method can respectively obtain the sodium sulphate and sodium chloride of high-purity, avoid mixed salt processing and recycle process In difficulty, be completed at the same time the process of separation of ammonia and salt, and waste water is made using heat exchange method to heat up and steam containing ammonia simultaneously Cooling is not necessarily to condenser, energy saving rationally using the heat in evaporation process, reduces cost for wastewater treatment, the ammonium in waste water It is recycled in the form of ammonium hydroxide, sodium chloride and sodium sulphate are recycled respectively with crystal form, and whole process does not have waste residue and liquid generation, real The purpose to turn waste into wealth is showed.

The crystallisation by cooling process of this method is available only containing the crystal solution of sodium sulfate crystal, also available to contain sulphur The crystal solution of sour sodium crystal and sodium chloride crystal.When obtaining only crystal solution containing sodium sulfate crystal, water can be directly isolated to obtain Sodium sulfate crystal is closed as product is used as after product, or the removal crystallization water therein, the first evaporation process can also be back to It is evaporated to obtain the sodium sulphate without containing the crystallization water；It, can when obtaining the crystal solution containing sodium sulfate crystal and sodium chloride crystal It is evaporated not contained so that obtained sodium sulfate crystal and sodium chloride crystal are back to the first evaporation process together The sodium sulfate crystal of the crystallization water.By crystallisation by cooling, the second evaporation can be made sufficiently to obtain sodium chloride, improve wastewater treatment Efficiency.

Further, this method has been obtained denseer ammonium hydroxide, convenient for the utilization of ammonium hydroxide, has been improved molten by the first evaporation The ion concentration of liquid improves the eduction rate of crystallisation by cooling, improves treatment effeciency；Matched by the second evaporation and cooling processing It closes, the second evaporation process is carried out at relatively high temperatures, improve the solid content and the second evaporation efficiency of the second evaporation, The circulation fluid scale of construction in processing system is reduced, can be simultaneously reached energy-saving effect.

Detailed description of the invention

Fig. 1 is a kind of flow diagram of the catalyst production waste water processing method of embodiment provided by the invention.

Description of symbols

1, the 2nd MVR vaporising device 53, the second mother liquor tank

2, equipment of crystallisation by cooling 54, third mother liquor tank

3, the first MVR vaporising device 55, low-temperature treatment tank

31, the first heat-exchanger rig 61, the first pH value measuring device

32, the second heat-exchanger rig 60, the second pH value measuring device

33, third heat-exchanger rig 70, the 11st circulating pump

34, the 4th heat-exchanger rig 71, first circulation pump

35, the 5th heat-exchanger rig 72, second circulation pump

36, the 6th heat-exchanger rig 73, third circulating pump

38, the 8th heat-exchanger rig 74, the 4th circulating pump

30, the tenth heat-exchanger rig 75, the 5th circulating pump

50, the first mother liquor tank 76, the 6th circulating pump

51, the first tank used for storing ammonia 77, the 7th circulating pump

52, the second tank used for storing ammonia 78, the 8th circulating pump

79, the 9th circulating pump 91, the second equipment for separating liquid from solid

80, the tenth circulating pump 92, third equipment for separating liquid from solid

84, the 14th circulating pump 93, the first equipment for separating liquid from solid

81, vacuum pump 101, the first compressor

82, circulating water pool 102, the second compressor

83, tail gas absorber

Specific embodiment

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, the present invention will be described, and the present invention is not limited by Fig. 1.

The processing method of catalyst production waste water provided by the invention, the catalyst production waste water contain NH₄ ⁺、SO₄ ^2-、Cl^- And Na⁺, this approach includes the following steps,

5) treatment fluid is subjected to third separation of solid and liquid；

Preferably, the waste water to be processed is the catalyst production waste water；Alternatively, the waste water to be processed contain it is described The liquid phase that catalyst production waste water and the third are separated by solid-liquid separation.

It is highly preferred that the waste water to be processed is the catalyst production waste water and the liquid that the third is separated by solid-liquid separation At least part of mixed liquor of phase.

Method provided by the invention, which can be directed to, contains NH₄ ⁺、SO₄ ^2-、Cl^-And Na⁺Catalyst production waste water at Reason, in addition to containing NH₄ ⁺、SO₄ ^2-、Cl^-And Na⁺Outside, to the catalyst production waste water, there is no particular limitation.

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

In the present invention, the tune of the first heat exchange, the pH value of the adjusting waste water to be processed and the waste water to be processed With process, (waste water to be processed contains the case where liquid phase that the catalyst production waste water is separated by solid-liquid separation with the third Under, need to carry out the allocation process of the waste water to be processed) carry out successively there is no particular limitation, can according to need and fitted When selection, completed before the waste water to be processed is carried out the first evaporation.

In the present invention, the purpose of first evaporation is that sulfate crystal is precipitated, and makes Waste water concentrating to be processed, together When obtain denseer ammonium hydroxide, improve the concentration of ion, improve the eduction rate of crystallisation by cooling.The degree that first evaporation carries out can It is selected with the ingredient of waste water as needed and to be processed, achievees the purpose that only to be precipitated sulfate crystal.Such as it can A small amount of steam containing ammonia is only obtained with control evaporation, to obtain the higher ammonium hydroxide of concentration；The journey of control evaporation can also be passed through Degree, is concentrated waste water to be processed, while controlling ion concentration, obtains pure sodium sulphate convenient for subsequent crystallisation by cooling, It can be evaporated by control and sufficiently be carried out, be concentrated waste water to be processed, improve the efficiency of crystallisation by cooling.

In the present invention, the vaporising device that this field routine can be used in first evaporation carries out, such as MVR evaporation dress It sets, single-effect evaporating equipment or multi-effect evaporating device.As MVR vaporising device, such as can be for selected from MVR falling film evaporator, MVR One of forced-circulation evaporator, MVR-FC continuous crystallisation evaporator, MVR-OSLO continuous crystallisation evaporator are a variety of.Its In, preferably MVR forced-circulation evaporator, MVR-FC continuous crystallisation evaporator, more preferably falling liquid film+forced circulation two-stage MVR Crystallizing evaporator.As single-effect evaporating equipment or the evaporator of multi-effect evaporating device, such as can be selected from downward film evaporator, liter Kestner long-tube evaporator, scraper-type evaporator, standard vertical-tubes multiple-effect steaming device, basket evaporator, external heating type evaporator, pressure follow One of ring evaporator and Liewen evaporator are a variety of.Wherein, preferably forced-circulation evaporator, external heating type evaporator. Each effect evaporator of the multi-effect evaporating device is made of heating room and vaporization chamber respectively, can also be as needed comprising other steamings Send out accessory, such as the demister for separating liquid foam further, the condenser for condensing secondary steam all, and decompression behaviour Vacuum plant etc. when making.There is no particular limitation for the evaporator quantity that the multi-effect evaporating device contains, can for 2 effect with On, more preferably 3-5 effect.A preferred embodiment according to the present invention, first evaporation pass through the first MVR evaporation dress Set 3 progress.

According to the present invention, there is no particular limitation for the condition of first evaporation, reaches the mesh for making Waste water concentrating to be processed ?.For example, it is 35 DEG C or more that the condition of first evaporation, which may include: temperature, pressure is -98kPa or more.In order to mention Height evaporation efficiency, it is preferable that first evaporation conditions include: temperature be 75 DEG C~130 DEG C, pressure be -73kPa~ 117kPa；Preferably, it is 85 DEG C~130 DEG C that the condition of first evaporation, which includes: temperature, and pressure is -58kPa~117kPa； Preferably, it is 95 DEG C~110 DEG C that the condition of first evaporation, which includes: temperature, and pressure is -37kPa~12kPa；Preferably, institute It is 95 DEG C~105 DEG C that the condition for stating the first evaporation, which includes: temperature, and pressure is -37kPa~-7kPa.

In the present invention, the operating pressure of the first evaporation is preferably the saturated vapor pressure of evaporated feed liquid.In addition, first steams The ability and wastewater flow rate to be processed that the evaporation capacity of hair can be handled according to equipment suitably select, such as can be 0.1m³/ h with Upper (such as 0.1m³/ h~500m³/h)。

From the point of view of the treatment effeciency for improving waste water, relative to the SO contained in waste water to be processed described in 1mol₄ ^2-, The Cl contained in the waste water to be processed^-For 14mol hereinafter, preferably 13.8mol hereinafter, preferably 13.75mol hereinafter, more Preferably 13.5mol hereinafter, more preferably 13mol hereinafter, being still more preferably 12mol hereinafter, being still more preferably 11mol is hereinafter, be still more preferably 10.5mol hereinafter, preferably 2mol or more, more preferably 2.5mol or more, further Preferably 3mol or more, such as can be 1.46-5.2mol.By by SO₄ ^2-And Cl^-Molar ratio control in above range, can So that first evaporation in sodium sulphate be precipitated and sodium chloride is not precipitated.

The condition evaporated by suitable control first, can evaporate to obtain 80 mass % of contained ammonia in waste water to be processed with On, preferably 90 mass % or more, such as can for 80 mass %, 83 mass %, 85 mass %, 86 mass %, 87 mass %, 88 mass %, 89 mass %, 90 mass %, 91 mass %, 93 mass %, 95 mass % or 98 mass % etc., the first ammonium hydroxide can With direct reuse in the production process of catalyst, perhaps with acid neutralization obtain carrying out after ammonium salt reuse or with water and corresponding Ammonium salt or ammonium hydroxide allotment use.

A preferred embodiment according to the present invention, first evaporation make sodium chloride in first concentrate Concentration is X or less, wherein X is under conditions of the first evaporation, and sodium sulphate and sodium chloride reach full in first concentrate With when sodium chloride concentration.Preferably, first evaporation makes the concentration 0.95X- of sodium chloride in first concentrate 0.999X.When crystallisation by cooling only obtains sodium sulfate crystal, it is preferable that described first is separated by solid-liquid separation obtained liquid phase (i.e. first Mother liquor) in Cl^-Concentration be 5.2mol/L or less；It is highly preferred that described first is separated by solid-liquid separation Cl in obtained liquid phase^-Concentration For 5.0mol/L or less.By the degree of the first evaporation of control, sulfate crystals more as far as possible is precipitated, while making the first solid-liquid The condition that sodium chloride is not precipitated when chlorine ion concentration in isolated liquid phase meets crystallisation by cooling, can be improved wastewater treatment Efficiency.

In the present invention, the carry out degree of first evaporation is carried out by way of the concentration of the first concentrate of monitoring, Specifically, the concentration for obtaining liquid by the first evaporation of control makes the first evaporation not make sodium chloride knot in above-mentioned range Partial crystallization goes out.Here the first evaporation obtains the concentration of liquid, is monitored by way of measuring density, density specifically can be used Meter carries out density measure.

According to the present invention, before waste water to be processed is carried out the first evaporation, the pH value for adjusting the waste water to be processed is big In 9, preferably greater than 10.8.In addition, for waste water to be processed pH value the adjusting upper limit there is no limit, such as can for 14 with Under, preferably 13.5 hereinafter, more preferable 13 or less.By carrying out the first evaporation under above-mentioned pH value, the steaming of ammonia can be promoted Hair obtains the higher ammonium hydroxide of concentration, and convenient for obtaining the sodium sulphate and sodium chloride crystal of high-purity in subsequent crystallization.

Before waste water to be processed is carried out the first evaporation, the specific example for adjusting the pH value of waste water to be processed can be lifted Out: 9,9.5,9.6,9.7,9.8,9.9,10,10.1,10.2,10.3,10.4,10.5,10.6,10.7,10.8,10.9,11, 11.1,11.2,11.3,11.4,11.5,11.6,11.7,11.8,11.9,12,12.2,12.4,12.6,12.8,13,13.5 or 14 etc..

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 waste water to be processed.There is no particular limitation for the alkaline matter, reaches the mesh of above-mentioned adjusting pH value ?.In order not to introduce new impurity in waste water to be processed, the purity of gained crystal is improved, the alkaline matter is preferably NaOH.The NaOH containing higher concentration in (i.e. third be separated by solid-liquid separation liquid phase) in addition, third mother liquor, it is also preferred that using In addition three mother liquors can add NaOH as the alkaline matter.

Adding manner as the alkaline matter is the adding manner of this field routine, but preferably makes alkaline matter Mixed in form of an aqueous solutions with waste water to be processed, for example, the aqueous solution containing alkaline matter can be passed into import it is to be processed It is mixed in the pipeline of waste water.For the content of alkaline matter in aqueous solution, there is no particular limitation, as long as can reach The purpose of above-mentioned adjusting pH value.But it in order to reduce the dosage of water, further reduces the cost, it is preferable to use alkaline matter is satisfied And aqueous solution or the second mother liquor.In order to monitor the pH value of the waste water to be processed, can be measured after above-mentioned adjusting pH value The pH value of the waste water to be processed.

A preferred embodiment according to the present invention, first evaporation carry out in the first MVR vaporising device 3, Before waste water to be processed is sent into the first MVR vaporising device 3, by the way that waste water to be processed is being sent into the first MVR vaporising device 3 Pipeline in import the aqueous solution containing alkaline matter and mixing, Lai Jinhang pH value is adjusted, and passes through first after adjustment PH value after pH value measuring device 61 and 60 pairs of the second pH value measuring device adjustings measures.

According to the present invention, it in order to make full use of the heat of the first steam containing ammonia, is preferably carried out by the waste water to be processed Before first evaporation, so that waste water to be processed and the first steam containing ammonia is carried out the first heat exchange, obtain the first ammonium hydroxide, while making wait locate Waste water heating is managed convenient for evaporation.

First heat exchange of a preferred embodiment according to the present invention, waste water to be processed and the first steam containing ammonia is logical It crosses the first heat-exchanger rig 31 and the 8th heat-exchanger rig 38 carries out, specifically, ammonia steam will be contained and pass sequentially through the 8th heat-exchanger rig 38 With the first heat-exchanger rig 31, while by waste water to be processed by the first heat-exchanger rig 31 and the first steam condensation containing ammonia liquid heat exchange, Then waste water to be processed is passed through the 8th heat-exchanger rig 38 and the first steam heat-exchanging containing ammonia.By the first heat exchange, first is obtained Ammonium hydroxide is stored in the first tank used for storing ammonia 51, while waste water to be processed being made to be warming up to 82 DEG C~137 DEG C, preferably 102 DEG C~117 DEG C, convenient for the progress of evaporation.

According to the present invention, in order to make full use of the heat of the first concentrate, the waste water to be processed is preferably being carried out the Before one evaporation, waste water to be processed and the first concentrate is made to carry out the first heat exchange, makes the cooling of the first concentrate convenient for cooling knot Crystalline substance, while making waste water heating to be processed convenient for evaporation.

A preferred embodiment according to the present invention, the first heat exchange of waste water to be processed and the first concentrate pass through 11st heat-exchanger rig 30 carries out, and waste water to be processed is exchanged heat by the 11st heat-exchanger rig 30 and the first concentrate.

There is no particular limitation for first heat-exchanger rig 31, the 11st heat-exchanger rig 30 and the 8th heat-exchanger rig 38, can To use various heat exchangers commonly used in the art, achieve the purpose that carry out heat exchange.It specifically, can be jacket type Heat exchanger, plate heat exchanger, shell-and-tube heat exchanger etc., wherein preferably plate heat exchanger.The material of the heat exchanger can root According to needing to be specifically chosen, such as in order to resist chloride ion corrosion, can choose material is two phase stainless steel, titanium or titanium alloy, Kazakhstan The heat exchanger of family name's alloy can select the heat exchanger containing plastic material when temperature is lower.

In the present invention, in order to improve the solid content in the first MVR vaporising device 3, the ammonia reduced in liquid contains Amount, preferably by by the first MVR vaporising device 3 evaporation after partially liq (namely be located at the first MVR vaporising device inside Liquid, also referred to as first circulation liquid) again return in the first MVR vaporising device 3 after heating and evaporate.It is above-mentioned by described The process of one circulation fluid back to the first MVR vaporising device 3 is preferably, by the first circulation liquid and in first time pH value It is again returned in the first MVR vaporising device 3 after adjusting and after the waste water to be processed mixing before being adjusted to second of pH value, For example, the first circulation liquid can be returned to the first heat-exchanger rig 31 and the 8th heat-exchanger rig 38 by the 5th circulating pump 75 Between waste water conveyance conduit in mixed with waste water to be processed, then by second of pH value adjust and then pass through 8th heat-exchanger rig 38 carries out heat exchange, is finally sent into the first MVR vaporising device 3.Here, first reflux ratio is Refer to: the total amount of liquid in the first MVR vaporising device 3 of regurgitant volume and feeding subtracts the ratio of regurgitant volume.The reflux ratio can root It is appropriately configured according to evaporation capacity, needed for guaranteeing that the first MVR vaporising device 3 can evaporate under given evaporating temperature The water and ammonia to be measured.For example, the first reflux ratio of first evaporation can be 10-200, preferably 50-100.

In the case where, according to the invention it is preferred to, the method also includes after first steam containing ammonia is compressed again Carry out first heat exchange.The compression of first steam containing ammonia can be carried out by the first compressor 101.By to described First steam containing ammonia is compressed, and to input energy in MVR vapo(u)rization system, guarantees that waste water heating-evaporation-cooling process is continuous Progress needs to input starting steam when MVR evaporation process starts, only passes through the first compressor 101 after reaching continuously running state Energy supply, it is no longer necessary to input other energy.First compressor 101 can use various compressions commonly used in the art Machine, such as centrifugal blower, turbocompressor or lobed rotor compressor etc..After first compressor 101 compression, described first The temperature of the steam containing ammonia increases 5 DEG C~20 DEG C.

In the present invention, the first concentrate of the sulfur acid sodium crystal obtains sodium sulphate 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 one of centrifugation, filtering, sedimentation or a variety of can be selected from.

According to the present invention, first concentrate first be separated by solid-liquid separation can using the first equipment for separating liquid from solid (such as For centrifuge, band filter, flame filter press etc.) it carries out.As shown in Figure 1, after described first is separated by solid-liquid separation, the first solid-liquid point The first mother liquor obtained from device 93 is temporarily stored into the first mother liquor tank 50, and cooling knot can be sent by the 11st circulating pump 70 Brilliant device 2 carries out crystallisation by cooling.In addition, be difficult to avoid that on obtained sodium sulfate crystal can adsorb certain chloride ion, free ammonia, The impurity such as hydroxide ion reduce the peculiar smell of solid salt to remove the impurity of absorption, reduce corrosivity, improve the crystal Purity, it is preferable that sodium sulfate crystal water, the catalyst production waste water or metabisulfite solution carry out first washing simultaneously It is dry.

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 for 1 time with On, the sodium sulfate crystal of higher purity, preferably 2-4 times in order to obtain.During elutriation, made with the catalyst production waste water It is not recycled generally when liquid to eluriate, can be used when doing elutriation liquid using the cleaning solution of the first washing recycling with circulated in countercurrent. Before carrying out the elutriation, tentatively separation of solid and liquid is carried out preferably by way of sedimentation and obtains the slurries (liquid of sulfur acid sodium crystal Content is 35 mass % or less, which preferably carries out in the device well known in the art such as settling tank, settling tank).It washes in a pan During washing, relative to the slurries of 1 parts by weight sulfur acid sodium crystal, eluriating the liquid used is 1~20 parts by weight.In addition, leaching It washes it is preferable to use aqueous sodium persulfate solution progress, the concentration of the aqueous sodium persulfate solution is preferably corresponding to the sodium sulfate crystal to be washed At a temperature of sodium chloride and sodium sulphate reach the concentration of sodium sulphate in the aqueous solution of saturation simultaneously.In order to further increase the effect of elutriation Fruit obtains the higher sodium sulfate crystal of purity, it is preferable to use the liquid that elution obtains carries out above-mentioned elutriation, it is preferable to use water or sulphur Acid sodium solution.For the liquid that washing generates, before the first heat exchange before preferably returning it to the first evaporation is completed.

A preferred embodiment according to the present invention carries out the first concentrate of sulfur acid sodium crystal by sedimentation After preliminary separation of solid and liquid, first time elutriation is carried out in eluriating tank with the catalyst production waste water, then reuses subsequent wash The liquid obtained when washing sodium sulfate crystal is eluriated at another and carries out second of elutriation in tank, and the slurry eluriated twice will be finally passed through Liquid is sent into equipment for separating liquid from solid and is separated by solid-liquid separation, and the crystal being separated by solid-liquid separation is eluted with aqueous sodium persulfate solution again, and The liquid that elution is obtained back in eluriating for the second time.By above-mentioned washing process, the sodium sulfate crystal that not only makes Purity improves, and introducing cleaning solution that will not be excessive, improves the efficiency of wastewater treatment.

In the present invention, the crystallisation by cooling is available only containing the crystal solution of sodium sulfate crystal, also available to contain There is the crystal solution of sodium sulfate crystal and sodium chloride crystal.So that sodium sulphate precipitation, makes sodium sulphate isolated sulphur from waste water When sour sodium crystal is purpose, only contain sodium sulfate crystal in the crystal solution that the preferably described crystallisation by cooling makes.At this point, obtain Sodium sulfate crystal (i.e. second is separated by solid-liquid separation obtained solid phase) is hydrated sulfuric acid sodium crystal (such as Disodium sulfate decahydrate crystal), can Can also remove the crystallization water by processes such as heating, obtain sodium sulfate crystal, first can also be back to directly as product Evaporation process is evaporated to obtain the sodium sulfate crystal without containing the crystallization water.In addition, to obtain without containing the crystallization water When sodium sulphate is purpose, containing sodium sulfate crystal, (hydrated sulfuric acid sodium is brilliant in the crystal solution that the crystallisation by cooling can make Body) and sodium chloride crystal.At this point, it is preferred that sodium sulfate crystal and sodium chloride crystal (i.e. the second solid-liquid point that crystallisation by cooling is obtained From obtained solid phase) it is back to the first evaporation process is together evaporated to obtain the sodium sulfate crystal without containing the crystallization water. As the method that the crystal for obtaining crystallisation by cooling is back to the first evaporation process, the pH before being preferably returned to the first evaporation is adjusted Before the first heat exchange, such as it is back to before the first pH value regulating device 61 in waste pipe.

A preferred embodiment according to the present invention, the sodium sulfate crystal of high-purity, preferably described cold in order to obtain But crystallization is not precipitated sodium chloride crystal to get arriving only containing the crystal solution of sodium sulfate crystal, so as to well by sulfuric acid Sodium is separated from waste water.Sodium sulphate only is precipitated in the crystallisation by cooling, it is not excluded that sulfate crystal entrainment or adsorption Sodium chloride.In the present invention, it is preferred in obtained sodium sulfate crystal sodium sulphate content be 92 mass % or more, more preferably 96 Quality % or more, further preferably 98 mass % or more), it is to be understood that the amount of the obtained sodium sulfate crystal with Butt meter.It can consider only sodium sulphate precipitation when the content of sodium sulphate is above range in obtained sodium sulfate crystal.That is, In obtained sodium sulfate crystal the total content of the impurity such as sodium chloride below 8 mass % when can think only sodium sulphate precipitation.

In order to guarantee that crystallisation by cooling obtains sodium sulfate crystal, SO in excellent first mother liquor₄ ^2-Concentration be preferably 0.01mol/L or more, more preferably 0.07mol/L or more, further preferably 0.1mol/L or more, still more preferably for 0.2mol/L or more, particularly preferably 0.3mol/L or more.According to the present invention, brilliant in order to improve the sodium sulphate that crystallisation by cooling obtains The purity of body, Cl in first mother liquor^-Concentration be preferably 5.2mol/L hereinafter, more preferably 5mol/L is hereinafter, further Preferably 4.5mol/L is hereinafter, be still more preferably 4mol/L hereinafter, to make sodium chloride in crystallisation by cooling not be precipitated.

By by the SO in the first mother liquor₄ ^2-、Cl^-Concentration is controlled in above range, and the first evaporation can be made sufficiently to carry out, It can make in crystallisation by cooling that sodium sulphate is precipitated simultaneously and sodium chloride is not precipitated, to achieve the purpose that efficiently separate sodium sulphate.? In the present invention, if the SO in first mother liquor₄ ^2-、Cl^-Concentration not within the above range, crystallisation by cooling can carried out Before carry out concentration adjusting, the concentration adjust preferably using the catalyst production waste water, wash sodium sulfate crystal washing and/ Or third mother liquor etc. carries out, it can specifically mixed in the first mother liquor tank 50 with the first mother liquor.

SO in first mother liquor₄ ^2-The specific example of content can be enumerated: 0.01mol/L, 0.03mol/L, 0.05mol/ L, 0.08mol/L, 0.1mol/L, 0.2mol/L, 0.3mol/L, 0.4mol/L, 0.5mol/L, 0.6mol/L or 0.7mol/L, Deng.

In addition, Cl in first mother liquor^-The specific example of content can be enumerated: 2.0mol/L, 2.2mol/L, 2.4mol/L、2.6mol/L、2.8mol/L、3mol/L、3.2mol/L、3.4mol/L、3.6mol/L、3.8mol/L、4mol/L、 4.5mol/L or 5mol/L etc..

Another preferred embodiment according to the present invention, second is separated by solid-liquid separation obtained solid phase not as wastewater treatment Product when, crystallisation by cooling can be such that sodium chloride crystallization is precipitated, that is, crystallisation by cooling obtains sodium sulfate crystal and chlorination simultaneously Sodium crystal, need at this time the sodium sulfate crystal that will be obtained and sodium chloride crystal be back to together the first evaporation process be evaporated from And obtain the sodium sulfate crystal without containing the crystallization water.It is matched by the first evaporation and crystallisation by cooling, the first evaporation can be made more Add and be easy to control, while improving the efficiency of wastewater treatment.

It is adjusted by the pH value before the first evaporation, so that the pH value of waste water to be processed is greater than 9, NH therein₄ ⁺Major part is with ammonia The form of molecule is evaporated out in the first evaporation, thus guarantee not to be precipitated during crystallisation by cooling ammonium sulfate and/or Ammonium chloride, simultaneously because the raising of sodium chloride concentration, can be improved the eduction rate of sodium sulphate.

In the present invention, the condition of the crystallisation by cooling can according to need appropriate selection, reach the sodium sulphate knot The effect that partial crystallization goes out.The condition of the crystallisation by cooling may include: temperature be -21.7 DEG C~17.5 DEG C, preferably -20 DEG C ~5 DEG C, more preferably -10 DEG C~5 DEG C, further -10 DEG C~0 DEG C, particularly preferably -4 DEG C~0 DEG C；Time cooling (to tie Residence time meter in brilliant device 2) be 5min or more, preferably 60min~180min, more preferably 90min~150min, into One step is preferably 120min~150min.By controlling the condition of crystallisation by cooling in above range, sodium sulphate can be made abundant It is precipitated, sodium chloride is made to be precipitated or not be precipitated as needed.

The specific example of temperature as above-mentioned crystallisation by cooling can be enumerated: -21 DEG C, -20 DEG C, -19 DEG C, -18 DEG C, -17 ℃、-16℃、-15℃、-14℃、-13℃、-12℃、-11℃、-10℃、-9℃、-8℃、-7℃、-6℃、-5℃、-4℃、-3 DEG C, -2 DEG C, -1 DEG C or 0 DEG C etc..

The specific example of time as above-mentioned crystallisation by cooling for example: 5min, 6min, 7min, 8min, 10min、15min、20min、25min、30min、35min、40min、45min、50min、52min、54min、56min、 58min、60min、65min、70min、75min、80min、85min、90min、95min、100min、105min、110min、 115min, 120min, 130min, 140min, 150min or 160min.

According to the present invention, there is no particular limitation for the mode that the crystallisation by cooling carries out, and can use continuously or in batches Mode carries out, as long as reaching reduces the temperature of the first mother liquor, makes the purpose of sulfate crystal precipitation, it is preferred to use continuous Crystallisation by cooling mode carries out.The crystallisation by cooling sodium sulphate can using various cooling crystallizing equipments commonly used in the art into Row, such as can be using the continuous cooling crystallizer with external cooling heat exchanger, or use the crystallization with cooling-part Tank carries out, such as equipment of crystallisation by cooling 2.The cooling-part can be made in equipment of crystallisation by cooling by way of importing cooling medium The first mother liquor be cooled to crystallisation by cooling needed for condition.Mixing component is preferably provided in the cooling crystallizing equipment, such as Blender etc., it is uniformly cooling by achieving the effect that the mixing of the first mother liquor, sodium sulphate therein can be made sufficiently to be precipitated, increased Crystallite dimension.It is preferably provided with circulating pump on the equipment of crystallisation by cooling, in order to avoid generating a large amount of fine grain cores, prevents circulation brilliant Crystal grain and impeller high velocity impact in slurry generate a large amount of secondary nucleus, and the circulating pump is preferably the centrifugal pump of the slow-speed of revolution, more excellent Be selected as big flow, the water conservancy diversion pump impeller of the slow-speed of revolution or big flow, low lift, the slow-speed of revolution axial-flow pump.

By carrying out the crystallisation by cooling under the above conditions, sodium sulphate can be made sufficiently to be precipitated in crystallisation by cooling, To achieve the purpose that separating-purifying sodium sulphate.

In the present invention, in order to control the Lens capsule in the equipment of crystallisation by cooling 2, containing for fine grain is reduced Amount, the partially liq for preferably crystallizing the process equipment of crystallisation by cooling 2 (namely the liquid inside equipment of crystallisation by cooling 2, Hereinafter be also referred to as cooling circulation liquid) mixed with the first mother liquor after return to equipment of crystallisation by cooling 2 in carry out crystallisation by cooling again.On Stating, which for example can pump 72 by second circulation back to the process that the equipment of crystallisation by cooling 2 crystallizes for cooling circulation liquid, to cool down Circulation fluid return to the 6th heat-exchange device 36 before, be again introduced into after being mixed with the first mother liquor the equipment of crystallisation by cooling 2 into Row crystallisation by cooling.The back amount of the cooling circulation liquid can lead to overcooled recycle ratio to define, the recycle ratio of the cooling Refer to: the total amount of liquid in internal circulating load and feeding equipment of crystallisation by cooling 2 subtracts the ratio of internal circulating load.The recycle ratio can basis The degree of supersaturation of sodium sulphate is appropriately configured in the equipment of crystallisation by cooling 2, to guarantee the granularity of sulfate crystal.In order to control The size distribution of crystal obtained by crystallisation by cooling processed, reduces the content of fine grain, and preferably control degree of supersaturation is less than 1.5g/L, more excellent It is selected as being less than 1g/L.

In the present invention, the crystal solution of the sulfur acid sodium crystal by second be separated by solid-liquid separation after obtain sodium sulfate crystal and Second mother liquor (i.e. second is separated by solid-liquid separation obtained liquid phase).There is no particular limitation for described second method being separated by solid-liquid separation, such as One of centrifugation, filtering and sedimentation or a variety of can be selected from.

According to the present invention, second separation of solid and liquid can use the second equipment for separating liquid from solid 91 (for example, centrifuge, band Formula filter, flame filter press etc.) it carries out.After described second is separated by solid-liquid separation, the second equipment for separating liquid from solid 91 is obtained second female Liquid is temporarily stored into the second mother liquor tank 53, and can be sent into the 2nd MVR vaporising device 1 by the 6th circulating pump 76 and be carried out the second steaming Hair.In addition, the impurity such as certain chloride ion, free ammonia, hydroxide ion can be adsorbed by being difficult to avoid that on obtained sodium sulfate crystal, When the sodium sulphate that crystallisation by cooling obtains is as product, in order to remove the impurity of absorption, the peculiar smell of solid salt is reduced, reduces corrosion Property, improve the purity of the crystal, it is preferable that sodium sulfate crystal water or metabisulfite solution carry out the second washing, need It can be dried when obtaining anhydrous sodium sulfate.Second mode of washing preferably elutes, and carries out preferably after separation of solid and liquid Elution.

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 solid-liquid separating equipment of domain routine carries out, and can also carry out in the equipment for separating liquid from solid of segmentation.For above-mentioned washing without spy Other restriction can be carried out by the method for this field routine.There is no particular limitation for the number of the washing, can be 1 time More than, the sodium sulfate crystal of higher purity, preferably 2-4 times in order to obtain.It is preferable to use aqueous sodium persulfate solution (institutes for second washing It states sodium chloride and sodium sulphate at the concentration preferably temperature corresponding to sodium sulfate crystal to be washed of aqueous sodium persulfate solution while reaching The concentration of sodium sulphate in the aqueous solution of saturation) it carries out.The liquid generated for washing, it is preferable that water or aqueous sodium persulfate solution are washed It washs liquid and is back to equipment of crystallisation by cooling 2, such as equipment of crystallisation by cooling 2 can be back to by the 8th circulating pump 78.

A preferred embodiment according to the present invention, the crystal solution containing sodium sulphate obtained by crystallisation by cooling Afterwards, it is separated by solid-liquid separation by equipment for separating liquid from solid, also, use aqueous sodium persulfate solution (institute again for obtained crystal is separated by solid-liquid separation The concentration of aqueous sodium persulfate solution is stated as sodium chloride and sodium sulphate at the temperature corresponding to sodium sulfate crystal to be washed while reaching saturation Aqueous solution in sodium sulphate concentration) eluted, and by the obtained liquid of elution back to equipment of crystallisation by cooling 2.By upper Washing process is stated, the purity for the sodium sulfate crystal that can be improved.

According to the present invention, in order to make full use of the cooling capacity of the second mother liquor, preferably by the first mother liquor carry out crystallisation by cooling it Before, the second mother liquor and the first mother liquor are subjected to the second heat exchange.

A preferred embodiment according to the present invention, second heat exchange are carried out by the second heat-exchanger rig 32, Specifically, the second mother liquor and the first mother liquor are passed through into the second heat-exchanger rig 32 respectively, so that the two is carried out heat exchange, to make first The temperature of mother liquor reduces the progress for being convenient for crystallisation by cooling, while increases the temperature of the second mother liquor convenient for the second evaporation.Pass through After two heat-exchanger rigs 32 carry out the second heat exchange, the temperature of the first mother liquor is -20.7 DEG C~16.5 DEG C, preferably -5 DEG C~10 DEG C, close to the temperature of crystallisation by cooling.

According to the present invention, for the ease of the progress of crystallisation by cooling, first mother liquor and freezing liquid is subjected to the second heat and handed over It changes.Second heat exchange of a preferred embodiment according to the present invention, first mother liquor and freezing liquid is changed by the 6th Thermal 36 carries out, and specifically, freezing liquid and the first mother liquor is passed through the 6th heat-exchanger rig 36 respectively, and the two is made to carry out hot friendship It changes, so that making the temperature of the first mother liquor reduces the progress for being convenient for crystallisation by cooling.The freezing liquid can routinely be used using this field In the freezing liquid of cooling, as long as the temperature of the first mother liquor can be made to meet the needs of crystallisation by cooling.

There is no particular limitation for second heat-exchanger rig 32 and the 6th heat-exchanger rig 36, and this field, which can be used, routinely to be made Various heat exchangers achieve the purpose that carry out heat exchange.Specifically, can for jacketed type exchanger, plate heat exchanger, Shell-and-tube heat exchanger etc., wherein preferably plate heat exchanger.The material of the heat exchanger can according to need specific choice, such as In order to resist chloride ion corrosion, the heat exchanger that material is two phase stainless steel, titanium or titanium alloy, Hastelloy can choose, in temperature The heat exchanger containing plastic material can be selected when spending lower.Preferred heat exchanger of the selection containing plastic material of second heat-exchanger rig 32.

In the present invention, the purpose of second evaporation is that sodium chloride and/or sodium sulphate is precipitated, and makes further ammonia Evaporation, to achieve the purpose that separate the ammonia and salt in waste water.According to the present invention, the condition evaporated by control second, with The continuous reduction of solvent, is precipitated sodium chloride first, and then sodium sulphate may be made to be precipitated, and obtain sodium chloride-containing crystal second is dense Contracting liquid.In order to reduce the quantity of circulating water in processing system, improving the efficiency of the second evaporation and then improve the efficiency of wastewater treatment, institute The degree for stating the second evaporation progress preferably makes sodium chloride and sodium sulphate while being precipitated, that is to say, that the second evaporation is preferably contained Second concentrate of sodium sulfate crystal and sodium chloride crystal.

In the present invention, the vaporising device that this field routine can be used in second evaporation carries out, such as MVR evaporation dress It sets, single-effect evaporating equipment or multi-effect evaporating device.The specific device in the first evaporation, is not repeating herein.In the present invention, Second evaporation is preferably carried out by the 2nd MVR vaporising device 1.Wherein, preferably MVR forced-circulation evaporator, MVR-FC Continuous crystallisation evaporator, more preferably falling liquid film+forced circulation two-stage MVR crystallizing evaporator.

In the present invention, there is no particular limitation for the evaporation conditions of second evaporation, can according to need appropriate selection, Achieve the purpose that crystal is precipitated.The condition of second evaporation may include: that the condition of second evaporation includes: temperature Degree is 35 DEG C or more, and pressure is -98kPa or more；Preferably, it is 45 DEG C~175 that the condition of second evaporation, which includes: temperature, DEG C, pressure is -95kPa~653kPa；Preferably, it is 60 DEG C~175 DEG C that the condition of second evaporation, which includes: temperature, pressure For -87kPa~653kPa；Preferably, it is 75 DEG C~175 DEG C that the condition of second evaporation, which includes: temperature, and pressure is -73kPa ~653kPa；Preferably, it is described second evaporation condition include: temperature be 80 DEG C~130 DEG C, pressure be -66kPa~ 117kPa；Preferably, it is 95 DEG C~110 DEG C that the condition of second evaporation, which includes: temperature, and pressure is -37kPa~12kPa；It is excellent Selection of land, it is 105 DEG C~107 DEG C that the condition of second evaporation, which includes: temperature, and pressure is -8kPa~0kPa.

In the present invention, the operating pressure of the second evaporation is preferably the saturated vapor pressure of evaporated feed liquid.In addition, second steams The ability and wastewater flow rate to be processed that the evaporation capacity of hair can be handled according to equipment suitably select, such as can be 0.1m³/ h with Upper (such as 0.1m³/ h~500m³/h)。

In order to preferably obtain sodium chloride crystal in the second evaporation process, it is separated by solid-liquid separation preferably with respect to described in 1mol second The SO contained in obtained liquid phase₄ ^2-, described second is separated by solid-liquid separation the Cl contained in obtained liquid phase^-For 7.15mol or more, more Preferably 10mol or more, further preferably 20mol or more are still more preferably 44mol or more, still more preferably for 50mol or more is still more preferably 74mol or more, more preferably 230mol hereinafter, such as 44-50mol, such as or 9.5mol、10.5mol、11mol、11.5mol、12mol、12.5mol、13mol、13.5mol、14mol、14.5mol、15mol、 15.5mol、16mol、16.5mol、17mol、17.5mol、18mol、18.5mol、19mol、19.5mol、20mol、21mol、 22mol, 23mol, 25mol, 27mol, 29mol, 31mol, 35mol, 40mol, 45mol, 50mol, 60mol, 65mol etc..It is logical It crosses SO₄ ^2-And Cl^-Molar ratio control can to handle to obtain pure sodium chloride by cooling after above range, evaporation brilliant Body realizes the separation of sodium sulphate and sodium chloride.

According to the present invention, from the aspect of improving waste water treatment efficiency, the higher the better for the second evaporation carry out degree； But if the second evaporation is more than to a certain degree, it will so that cooling processing is unable to get the treatment fluid for containing only sodium chloride crystal, this Although when can make dissolution of crystals by adding the modes such as water in treatment fluid, will affect the efficiency of wastewater treatment.Therefore institute The carry out degree for stating the second evaporation preferably makes sodium chloride crystal and sodium sulfate crystal while being precipitated, and cooling processing can make Sodium sulfate crystal dissolution in second concentrate of sodium chloride-containing crystal；That is, preferred steps 3) obtained sodium chloride-containing crystal The second concentrate be sodium chloride-containing crystal and sodium sulfate crystal concentrate, and cooling processing keeps the sodium chloride-containing brilliant Sodium sulfate crystal dissolution in the concentrate of body and sodium sulfate crystal.In order to enable the cooling processing can make sodium chloride-containing brilliant Sodium sulfate crystal dissolution in the concentrate of body and sodium sulfate crystal, such as can control the evaporation degree of second evaporation, Making the concentration Y or less of sodium sulphate in treatment fluid, (wherein, Y is sodium sulphate and chlorination in treatment fluid under conditions of cooling processing The concentration of sodium sulphate when sodium reaches saturation).From in subsequent cooling treatment process, sodium chloride is precipitated and sodium sulphate as far as possible The viewpoint being completely dissolved considers, it is preferable that second evaporation makes the concentration 0.9Y-0.99Y of sodium sulphate in treatment fluid, more Preferably 0.95Y-0.98Y.By the way that the extent control of the second evaporation within the above range, can guaranteed the second evaporation process Middle sodium chloride precipitation as much as possible, and in cooling processing, sodium sulphate is completely dissolved, and final separation is brilliant to pure sodium chloride Body.By as far as possible second evaporation in crystallize sodium chloride, waste water treatment efficiency can be improved, it is energy saving.

In the present invention, the carry out degree of second evaporation obtains liquid by the evaporation capacity of the second evaporation of monitoring The mode of amount carries out, and specifically, controls cycles of concentration by evaporation capacity, that is, ammonium hydroxide amount of the second evaporation of control, makes the second steaming Sending out the sulfate crystal being precipitated in the second obtained concentrate being capable of the dissolution when cooling down processing.Here the second journey being concentrated by evaporation Degree, is monitored by way of measuring the second evaporation capacity, and mass flowmenter specifically can be used and carry out flow measurement, can survey The amount for measuring secondary steam, can also measure the amount of condensate liquid.

In the present invention, in order to improve the liquid salinity in the 2nd MVR vaporising device 1, the ammonia in liquid is reduced Content, the partially liq for preferably evaporating process the 2nd MVR vaporising device 1 (namely inside the 2nd MVR vaporising device Liquid, also referred to as second circulation liquid hereinafter) back to evaporating in the 2nd MVR vaporising device 1, the is again returned to after preferably heating It is evaporated in two MVR vaporising devices 1.The above-mentioned process by second circulation liquid back to the 2nd MVR vaporising device 1 for example can be with Third heat exchanging process is returned to by the 7th circulating pump 77.It is described second evaporation the second reflux ratio refer to: regurgitant volume with give Enter the ratio that the total amount of liquid in the 2nd MVR vaporising device 1 subtracts regurgitant volume.Second reflux ratio can according to evaporation capacity into Row is suitably set, required for guaranteeing that the 2nd MVR vaporising device can evaporate under given second evaporating temperature The water and ammonia of amount.Second reflux ratio of second evaporation for example can be 10-200, preferably 60-110.

In the case where, according to the invention it is preferred to, the method also includes after second steam containing ammonia is compressed again Carry out third heat exchange.The compression of second steam containing ammonia can be carried out by the second compressor 102.By containing ammonia to second Steam is compressed, and to input energy in MVR vapo(u)rization system, guarantees that waste water heating-evaporation-cooling process is carried out continuously, MVR It needs to input starting steam when evaporation process starts, only be energized by the second compressor 102 after reaching continuously running state, no longer Need to input other energy.Second compressor 102 can use various second compressors commonly used in the art, such as Centrifugal blower, turbocompressor or lobed rotor compressor etc..After second compressor 102 compression, described second steams containing ammonia The temperature of vapour increases 5 DEG C~20 DEG C.

According to the present invention, in order to make full use of the second evaporation to obtain the second steam containing ammonia in heat, preferably by institute It states the second mother liquor to be sent into before the 2nd MVR vaporising device 1, the second mother liquor and second steam containing ammonia is subjected to the friendship of third heat It changes.

The third heat exchange of a preferred embodiment according to the present invention, the second mother liquor and the second steam containing ammonia is distinguished It is carried out by third heat-exchanger rig 33 and the 4th heat-exchanger rig 34.Specifically, the second mother liquor is passed sequentially through into third heat-exchanger rig 33 and the 4th heat-exchanger rig 34, and the second steam containing ammonia is passed sequentially through into the 4th heat-exchanger rig 34 and third heat-exchanger rig 33, from And make the heating of the second mother liquor convenient for the second evaporation, while the second steam containing ammonia being made to condense to obtain ammonium hydroxide.It is exchanged heat by the third After 33 heat exchange of device, the temperature of second mother liquor is increased to 34 DEG C~109 DEG C, preferably 44 DEG C~109 DEG C；Pass through described After four heat-exchanger rigs, 34 heat exchange, the temperature of second mother liquor is increased to 42 DEG C~117 DEG C, preferably 52 DEG C~117 DEG C.

According to the present invention, for the heat in the second concentrate of the sodium chloride-containing crystal for making full use of the second evaporation to obtain Second concentrate of sodium chloride-containing crystal and the second mother liquor are carried out third heat exchange preferably before the evaporation of carry out second by amount.

The of a preferred embodiment according to the present invention, the second concentrate of sodium chloride-containing crystal and the second mother liquor Three heat exchanges are carried out by the 5th heat-exchanger rig 35.Specifically, by the second concentrate of the second mother liquor and sodium chloride-containing crystal point Not Tong Guo the 5th heat-exchanger rig 35, make the heating of the second mother liquor convenient for the second evaporation, while making the second of sodium chloride-containing crystal to be concentrated Liquid cooling is but convenient for cooling to handle.After 35 heat exchange of the 5th heat-exchanger rig, the temperature of second mother liquor is increased to 34 DEG C~109 DEG C, preferably 44 DEG C~109 DEG C

There is no particular limitation for the third heat-exchanger rig 33, the 4th heat-exchanger rig 34 and the 5th heat-exchanger rig 35, can be with Using various heat exchangers commonly used in the art, achieve the purpose that carry out heat exchange.Specifically, it can be changed for jacket type Hot device, plate heat exchanger, shell-and-tube heat exchanger etc., wherein preferably plate heat exchanger.The material of the heat exchanger can basis It needs to be specifically chosen, such as in order to resist chloride ion corrosion, can choose material is two phase stainless steel, titanium or titanium alloy, Kazakhstan The heat exchanger of alloy can select the heat exchanger containing plastic material when temperature is lower.Preferably, two-phase stainless steel plate type is selected Heat exchanger.

In the present invention, the purpose of the cooling processing is in the second concentrate for making the sodium chloride-containing crystal possible The sodium sulfate crystal dissolution contained, is precipitated sodium chloride further.The cooling processing makes the second of sodium chloride-containing crystal to be concentrated Sodium sulfate crystal dissolution in liquid, refers to sodium chloride crystal pure in order to obtain, the degree that second evaporation carries out need by Suitable control, that is to say, that the sodium sulphate in control mixed system is no more than the solubility under conditions of corresponding cooling processing, and It is not excluded for the sodium sulphate of sodium chloride crystallization entrainment or adsorption.Since the water content of crystal after being separated by solid-liquid separation is different, usual To sodium chloride crystal in sodium sulphate content below 8 mass % (preferably 4 mass % or less), in the present invention, obtain Sodium chloride crystal in sodium sulphate content below 8 mass % when can think sodium sulfate crystal dissolve.

There is no particular limitation for the condition that the cooling processing carries out, so that in the second concentrate of sodium chloride-containing crystal Sodium sulfate crystal can be completely dissolved in cooling treatment process, such as the condition for the processing that cools down may include: that temperature is 13 DEG C~100 DEG C, preferably 15 DEG C~45 DEG C, more preferably 15 DEG C~35 DEG C, further preferably 17.9 DEG C~35 DEG C.In order to Guarantee cooling processing effect, it is preferable that it is described cooling processing condition include: the time be 5min or more, preferably 5min~ 120min, more preferably 30min~90min；Further preferably 50min~60min.

As cooling processing temperature specific example for example: 13 DEG C, 14 DEG C, 15 DEG C, 15.5 DEG C, 16 DEG C, 16.5℃、17℃、17.5℃、17.9℃、18℃、18.5℃、19℃、19.5℃、20℃、21℃、23℃、25℃、27℃、30 DEG C, 31 DEG C, 31.5 DEG C, 32 DEG C, 33 DEG C, 34 DEG C, 35 DEG C, 40 DEG C, 45 DEG C, 50 DEG C, 55 DEG C etc..

As cooling processing time specific example for example: 5min, 6min, 7min, 8min, 10min, 15min、20min、25min、30min、35min、40min、45min、50min、52min、54min、56min、58min、 60min、70min、100min、120min。

According to the present invention, the cooling processing carries out in low-temperature treatment tank 55, the second concentrate of sodium chloride-containing crystal After low-temperature treatment tank 55 carries out cooling processing, the treatment fluid of the sodium chloride-containing crystal is obtained.The low-temperature treatment tank 55 does not have There is special restriction, such as can be thickener, the crystallizing tank with stirring and crystallizing tank with outer circulation etc., wherein preferably band The crystallizing tank of stirring.Low-temperature treatment tank 55 is preferably provided with mixing component, makes the cooling treatment process at the second concentrate In the state of mixing, such as can be excellent using the conventional mechanical stirring used, electromagnetic agitation and/or the external circulating device having Choosing is distributed the solid-liquid in the second concentrate and reaches uniform state.Second concentrate each section is set to keep temperature, dense by mixing Spend it is uniform, thus avoid sodium sulfate crystal dissolution cannot sufficiently carry out, improve cooling processing efficiency.Low-temperature treatment tank 55 is preferred It is provided with cooling-part, such as so that low-temperature treatment tank 55 is cooled to the required item of cooling processing by way of importing cooling medium Part.

According to the present invention, the third separation of solid and liquid can pass through third equipment for separating liquid from solid (for example, centrifuge, belt Filter, flame filter press etc.) 92 progress.After the third is separated by solid-liquid separation, the third that third equipment for separating liquid from solid 92 obtains is female Liquid (i.e. third be separated by solid-liquid separation liquid phase), which returns to the first MVR device 3, to carry out first again and evaporates, and can specifically pass through the 9th Before circulating pump 79 adjusts third mother liquor back to second of pH value.In addition, being difficult to avoid that on obtained sodium chloride crystal can inhale The impurity such as attached certain sulfate ion, free ammonia, hydroxide ion reduce the different of solid salt to remove the impurity of absorption Taste reduces corrosivity, improves the purity of the crystal, it is preferable that the sodium chloride crystal water, the catalyst production waste water Or sodium chloride solution carries out third washing and drying.In order to avoid the dissolution of sodium chloride crystal in washing process, it is preferable that described Sodium chloride crystal is washed with sodium-chloride water solution.It is highly preferred that the concentration of the sodium-chloride water solution is preferably to be washed Sodium chloride and sodium sulphate reach the concentration of sodium chloride in the aqueous solution of saturation simultaneously at temperature corresponding to sodium chloride crystal.

It is separated by solid-liquid separation the mode with third washing as above-mentioned third, 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.The third mode of washing includes eluriating and/or eluting.For above-mentioned elutriation and elution, there is no particular limitation, can To be carried out by the method for this field routine.There is no particular limitation for the number of the elutriation and elution, can be 1 time or more, The sodium chloride crystal of higher purity, preferably 2-4 times in order to obtain.During elutriation, the cleaning solution of third washing recycling is used It can be used when doing elutriation liquid with circulated in countercurrent.Before carrying out the elutriation, preferably tentatively it is separated by solid-liquid separation by way of sedimentation Obtain the slurries of sodium chloride-containing crystal (content liquid is 35 mass % or less).During elutriation, contain relative to 1 parts by weight The slurries of sodium chloride crystal, eluriating the liquid used is 1-20 parts by weight.It is preferable to use the sodium-chloride water solution (chlorinations for elution Sodium chloride and sodium sulphate reach saturation simultaneously at the concentration of the sodium water solution preferably temperature corresponding to sodium chloride crystal to be washed The concentration of sodium chloride in aqueous solution) it carries out.In order to further increase the effect of elutriation, the higher sodium chloride crystal of purity is obtained, In preferred situation, the leacheate that elution obtains can be used and eluriated.For washing generate liquid, it is preferable that water or Sodium-chloride water solution cleaning solution and elutriation liquid are back to the 2nd MVR vaporising device 1, such as pass through the tenth circulating pump 80 and return to second MVR vaporising device 1.

A preferred embodiment according to the present invention, by the processing for the sodium chloride-containing crystal that cooling is handled Liquid is carried out after being tentatively separated by solid-liquid separation by sedimentation, and the liquid obtained when with subsequent wash sodium chloride crystal eluriates tank at another In eluriated, then by through elutriation sodium chloride-containing crystal treatment fluid be sent into equipment for separating liquid from solid be separated by solid-liquid separation, Gu The isolated crystal of liquid uses sodium-chloride water solution again, and (concentration of the sodium-chloride water solution is right in sodium chloride crystal to be washed At a temperature of answering sodium chloride and sodium sulphate and meanwhile reach the concentration of sodium chloride in the aqueous solution of saturation) eluted, and will elute To liquid back to eluriate in as eluriate liquid.The washing process combined by above-mentioned elutriation and elution, not only makes The purity of sodium chloride crystal improves, and introducing cleaning solution that will not be excessive, improves the efficiency of wastewater treatment.

A preferred embodiment according to the present invention discharges the tail gas that crystallisation by cooling generates after except ammonia；It will The third heat exchange condenses remaining tail gas and discharges after except ammonia；First heat exchange is condensed remaining tail gas to pass through Except being discharged after ammonia.The tail gas that the tail gas that the crystallisation by cooling generates, that is, equipment of crystallisation by cooling 2 is discharged, the third heat exchange Condense the on-condensible gas of remaining tail gas i.e. the 4th heat-exchanger rig 34 discharge；The first hot cross ring condenses remaining tail gas i.e. the The tail gas of eight heat-exchanger rigs 38 discharge.By the way that above-mentioned tail gas is removed ammonia, the pollutant that can be further decreased in emission contains Amount, allows to 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 Recycled in absorption tower 83, can also by third circulating pump 73 from circulating water pool 82 to 83 water supplement of tail gas absorber, circulation 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 can also cocurrent, preferably adverse current.The recirculated water can be by additional Fresh water is supplemented.In order to guarantee 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 after absorbing tail gas or ammonium sulfate is back to 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 catalyst production waste water, as long as containing NH₄ ⁺、SO₄ ^2-、Cl^-And Na⁺ Waste water.In addition, method of the invention is particularly suitable for the processing of ammoniated wastewater with high salt.It is produced as catalyst of the invention Waste water is specifically as follows the waste water from molecular sieve, aluminium oxide or oil refining catalyst production process, is also possible to that molecule will be come from The waste water of sieve, aluminium oxide or oil refining catalyst production process carries out the waste water after following removal of impurities and concentration.It will preferably come from and divide The waste water of son sieve, aluminium oxide or oil refining catalyst production process carries out the waste water after following removal of impurities and concentration.

As the NH in the catalyst production waste water₄ ⁺It can be 8mg/L or more, preferably 300mg/L or more.

As the Na in the catalyst production waste water⁺Can be 510mg/L or more, preferably 1g/L or more, more preferably For 2g/L or more, further preferably 4g/L or more, further preferably 8g/L or more, further preferably 16g/L or more, into One step is preferably 32g/L or more, further preferably 40g/L or more, further preferably 50g/L or more, further preferably 60g/L or more.

As the SO in the catalyst production waste water₄ ^2-Can be 1g/L or more, preferably 2g/L or more, more preferably 4g/L or more, further preferably 8g/L or more, further preferably 16g/L or more, further preferably 32g/L or more, into One step is preferably 40g/L or more, further preferably 50g/L or more, further preferably 60g/L or more, further preferably 70g/L or more.

As the Cl in the catalyst production waste water^-It can be 970mg/L or more, more preferably 2g/L or more, into one Step is preferably 4g/L or more, further preferably 8g/L or more, further preferably 16g/L or more, further preferably 32g/L More than, further preferably 40g/L or more, further preferably 50g/L or more, further preferably 60g/L or more.

The NH contained in the catalyst production waste water₄ ⁺、SO₄ ^2-、Cl^-And Na⁺The upper limit there is no particular limitation.From useless Water is easy from the point of view of starting with, SO in catalyst production waste water₄ ^2-、Cl^-And Na⁺The upper limit be respectively 200g/L hereinafter, it is preferred that For 150g/L or less；NH in catalyst production waste water₄ ⁺For 50g/L hereinafter, preferably 30g/L or less.

In the present invention, the inorganic ion contained in the catalyst production 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 member The respective content of the inorganic ions such as plain ion is preferably 100mg/L hereinafter, more preferably 50mg/L is hereinafter, further preferably Following 10mg/L is not hereinafter, contain other inorganic ions particularly preferably.By controlling other inorganic ions in above-mentioned model It encloses, can be further improved the purity of finally obtained sodium sulfate crystal and sodium chloride crystal.It is raw in order to reduce the catalyst The content for producing other inorganic ions in waste water, preferably carries out following removal of impurities.

The TDS of the catalyst production waste water can be 1.6g/L or more, preferably 4g/L or more, more preferably 8g/L with On, further preferably 16g/L or more, further preferably 32g/L or more, further preferably 40g/L or more are further excellent It is selected as 50g/L or more, further preferably 60g/L or more, further preferably 100g/L or more, further preferably 150g/L More than, further preferably 200g/L or more.

In the present invention, the pH value of the catalyst production waste water is preferably 4-8, such as 6-7.

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

In the present invention, in order to reduce the concentration impurity ion in waste water, guarantee that the continuous-stable for the treatment of process carries out, drop Low equipment operation maintenance cost, the catalyst production waste water using processing method of the invention before being handled preferably through removing It is miscellaneous.Preferably, the removal of impurities is selected from one of separation of solid and liquid, chemical precipitation, absorption, ion exchange and oxidation or a variety of.

It can be filtering, centrifugation, sedimentation etc. as the separation of solid and liquid；It can be adjusting as the chemical precipitation PH, carbonate deposition, magnesium salts precipitating etc.；It can be physical absorption and/or chemisorption, specific absorption as the absorption Agent can select active carbon, silica gel, aluminium oxide, molecular sieve, natural clay etc.；As the ion exchange, strong acid can be used Any one in property resin cation, acidulous cation resin；As the oxidation, can use 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 catalyst production waste water.For Suspended matter can choose solid-liquid isolation method removal of impurities；For inorganic matter and organic matter, chemical precipitation method, ion exchange can choose Method, absorption method removal of impurities, such as Subacidity cation exchange process, active carbon adsorption etc.；It, can be using absorption for organic matter And/or the mode of oxidation cleans, wherein preferably ozone biological activated carbon adsorption and oxidation method.One according to the present invention preferred Embodiment, catalyst production waste water successively pass through chemical precipitation, filtering, Subacidity cation exchange process, ozone bioactivity Charcoal adsorption and oxidation method cleans.By above-mentioned dedoping step, most suspended substances, hardness, silicon and organic matter can be removed, is dropped Low device fouling risk, in addition, also avoiding vaporising device two since evaporation process of the invention carries out under strongly alkaline conditions The risk of silica fouling guarantees wastewater treatment process continuous and steady operation.

It in the present invention, can be before using processing method processing of the invention (preferably for the lower waste water of salt content After above-mentioned removal of impurities), so that salt content is reached range required by catalyst production waste water of the invention by being concentrated.It is preferred that Ground, it is described concentration selected from ED film concentration and/or it is reverse osmosis；It is highly preferred that described be concentrated by the concentration of ED film and reverse osmosis progress, There is no particular limitation for the sequencing of the ED film concentration and reverse osmosis progress.The ED film concentration and reverse osmosis treatment device It can carry out, can be specifically chosen according to the case where waste water to be processed in such a way that this field is conventional with condition.Specifically, make For ED film concentration, unidirectional electrodialysis system or pole-reversing electroosmosis system can be selected to carry out；It, can be with as described reverse osmosis Rolled film, plate membrane, dish tubular membrane, vibrating membrane or combinations thereof is selected to carry out.Wastewater treatment can be improved by the concentration Efficiency avoids energy waste caused by largely evaporating.

In a preferred embodiment of the invention, catalyst production waste water is the waste water in process of producing molecular sieve It cleans, and passes through by chemical precipitation, filtering, Subacidity cation exchange process and ozone biological activated carbon adsorption and oxidation method Waste water after the concentration of ED film and reverse osmosis concentration.

Condition as above-mentioned chemical precipitation is preferred are as follows: uses sodium carbonate as inorganic agent, relative to 1mol calcium in waste water 1.2-1.4mol sodium carbonate is added in ion, and the pH for adjusting waste water is greater than 7, and reaction temperature is 20-35 DEG C, reaction time 0.5- 4h。

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

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

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

Condition as the concentration of above-mentioned ED film is preferred are as follows: electric current 145-155A, voltage 45-65V.It for example can be with as ED film For the ED film of Japanese A Sitong company production.

It is preferred as above-mentioned reverse osmosis condition are as follows: operating pressure 5.4-5.6MPa, 25-35 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.

According to the present invention, when starting to carry out wastewater treatment, catalyst production waste water can be used and directly go into operation, if catalysis The ion concentration of agent production waste water meets condition of the invention, can first carry out the first evaporation, cooling with condition according to the invention Crystallization carries out the second evaporation, cooling processing again；If the ion concentration of catalyst production waste water is unsatisfactory for condition of the invention, can First to carry out the second evaporation, cooling processing, obtain the second concentrate and be separated by solid-liquid separation to obtain sodium chloride crystal and the second mother liquor, then Second mother liquor is mixed with the catalyst production waste water to adjust the ion concentration of waste water to be processed be of the presently claimed invention The first evaporation is carried out again after range, crystallisation by cooling obtains sodium sulfate crystal.Certainly the initial stage also can be used sodium sulphate or The ion concentration in waste water to be processed is adjusted in sodium chloride, as long as meeting the waste water to be processed in the present invention treats place Manage SO in waste water₄ ^2-、Cl^-Requirement.

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

In following embodiment, catalyst production 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 are successively concentrated by ED film With the waste water after reverse osmosis concentration.

Embodiment 1

As shown in Figure 1, catalyst production waste water (is contained NaCl58g/L, Na₂SO₄ 66g/L、NH₄Cl 26.3g/L、 (NH₄)₂SO₄30.4g/L, pH 6.8) it with inlet amount is 5m³The speed of/h is sent in the pipeline of processing system, into pipeline It imports the sodium hydrate aqueous solution that concentration is 45.16 mass % and carries out the adjusting of first time pH value, pass through the first pH value measuring device 61 (pH meters) are monitored (measured value 8.0) to the pH value after adjusting, are then produced catalyst by first circulation pump 71 A part of waste water is sent into the first heat-exchanger rig 31 and the first steam condensation containing ammonia liquid exchanges heat, another part and the 9th circulating pump 79 After the third mother liquor mixing of return, be sent into the 11st heat-exchanger rig 30 and exchange heat with the first mother liquor, by two parts merge to obtain to Handle waste water (wherein SO₄ ^2-With Cl^-Molar ratio be 1:2.42), by waste water to be processed be sent into the 8th heat-exchanger rig 38 and first After steam heat-exchanging containing ammonia makes waste water to be processed be warming up to 112 DEG C, then be sent into the first MVR vaporising device 3 pipeline in import it is dense The sodium hydrate aqueous solution that degree is 45.16 mass % carries out second of pH value adjusting, passes through 60 (pH of the second pH value measuring device Meter) (measured value 10.8) is monitored to the pH value after adjusting.

First evaporation carries out in the first MVR vaporising device 3 (falling liquid film+the second crystallizing evaporator of forced circulation two-stage MVR), The temperature of evaporation is 105 DEG C, and pressure is -7.01kPa, evaporation capacity 4.12m³/ h obtains the first steam containing ammonia and sulfur acid sodium First concentrate of crystal.First steam containing ammonia after (temperature rises 16 DEG C), is successively existed after the compression of the first compressor 101 Heat exchange is carried out with waste water to be processed and catalyst production waste water in 8th heat-exchanger rig 38 and the first heat-exchanger rig 31, obtains the One ammonium hydroxide is simultaneously stored in the first tank used for storing ammonia 51.In addition, in order to improve the solid content in the first MVR vaporising device 3, by Partially liq after evaporating in one MVR vaporising device 3 is recycled to the 8th heat exchange by the 5th circulating pump 75 as first circulation liquid Then device 38 is again introduced into the first MVR vaporising device 3 and carries out the first evaporation (the first reflux ratio is 82).It is steamed by the first MVR The densitometer being arranged on transmitting apparatus 3 is monitored the degree of the first evaporation, and the concentration for controlling sodium chloride in the first concentrate is 273.5g/L(4.675mol/L)。

First concentrate of the sulfur acid sodium crystal that the evaporation of above-mentioned first MVR vaporising device 3 obtains is sent into the first solid-liquid After separator 93 (centrifuge) carries out the first separation of solid and liquid, 1.90m is obtained per hour³Contain NaCl 273.5g/L, Na₂SO₄ 60.7g/L、NaOH 1.67g/L、NH₃The first mother liquor (Cl of 0.43g/L^-Concentration be 4.675mol/L, SO₄ ^2-Concentration be 0.4275mol/L), it is temporarily stored into the first mother liquor tank 50, is separated by solid-liquid separation gained solid sodium sulfate and (obtains aqueous 1.5 matter per hour The sulfate crystal filter cake 500.52kg of % is measured, wherein the content of sodium chloride is 2.0 mass % or less) it is filtered with sulfate crystal The metabisulfite solution of the equal 60g/L of cake butt quality elutes, and obtaining sodium sulphate 493.51kg after dry per hour, (purity is 99.5 mass %), cleaning solution by the 14th circulating pump 84 be recycled into the pipeline before the 8th heat-exchanger rig 38 with catalysis Agent production waste water is mixed, and is then again introduced into the first MVR vaporising device 3 and is carried out the first evaporation.

First mother liquor is sent into the 11st heat-exchanger rig 30 by the 11st circulating pump 70 to exchange heat with catalyst production waste water Afterwards, being re-fed into the second heat-exchanger rig 32 (heat exchanger of plastic material) and the heat exchange of the first mother liquor makes the first mother liquor be cooled to 16 DEG C, Then it mixes with the circulation fluid of the equipment of crystallisation by cooling 2 of 72 conveying of second circulation pump, is changed through the 6th heat-exchanger rig 36 with freezing liquid After hot further cooling, it is sent into equipment of crystallisation by cooling 2 (continuous freezing and crystallizing tank) and carries out crystallisation by cooling, obtain sulfur acid sodium crystal Crystal solution.Wherein, the temperature of crystallisation by cooling is -2 DEG C, time 120min, and the internal circulating load for controlling crystallisation by cooling is 84m³/ h, The degree of supersaturation for controlling refrigerating process sodium sulphate is 1.0g/L.

The crystal solution for the sulfur acid sodium crystal that above-mentioned equipment of crystallisation by cooling 2 is obtained is sent into the second equipment for separating liquid from solid 91 After (centrifuge) is separated by solid-liquid separation, 1.74m is obtained per hour³Contain NaCl 299g/L, Na₂SO₄ 15.6g/L、NaOH 1.8g/L、NH₃The second mother liquor of 0.46g/L is temporarily stored into the second mother liquor tank 53, is obtained purity per hour and is 98 mass %, contains The sal glauberi crystalli-zation cake 200.59kg of 56 mass % of water is dissolved with the catalyst production waste water, then passes through first Circulating pump 71 is sent into the first evaporation of the first MVR vaporising device 3 progress and produces anhydrous sodium sulfate.

Second evaporation process is in 1 (falling liquid film+forced circulation two-stage the second evaporative crystallization of MVR of the 2nd MVR vaporising device Device) in carry out.After a part of second mother liquor is sent into third heat-exchanger rig 33 (two phase stainless steel plate heat exchanger) and compression The heat exchange of the second liquid of steam condensation containing ammonia, another part is sent into the 5th heat-exchanger rig 35 (two phase stainless steel plate heat exchanger) and the The second concentrates of sodium chloride-containing crystal that two evaporations obtain carry out heat exchange, then merge the second mother liquor of two parts and are sent into the After carrying out heat exchange with the second steam containing ammonia in four heat-exchanger rigs 34 (two phase stainless steel plate heat exchanger), evaporated in the 2nd MVR Device 1 carries out the second evaporation and obtains the second concentrate and the second steam containing ammonia of sodium chloride-containing crystal.Second evaporation temperature be 105 DEG C, pressure is -7.02kPa, evaporation capacity 1.57m³/h.Second steam containing ammonia (temperature after the compression of the second compressor 102 Degree rises 16 DEG C) after, heat exchange successively is carried out with the second mother liquor in the 4th heat-exchanger rig 34 and third heat-exchanger rig 33, is obtained Second ammonium hydroxide is simultaneously stored in the second tank used for storing ammonia 52.In addition, in order to improve the solid content in the 2nd MVR vaporising device 1, it will Partially liq in 2nd MVR vaporising device 1 after second evaporation is fed again into second by the 7th circulating pump 77 as circulation fluid MVR vaporising device 1 carries out the second evaporation (the second reflux ratio is 90).Pass through the mass flow being arranged on the 2nd MVR vaporising device 1 It counts and the degree of the second evaporation is monitored, the second evaporation capacity of control is 1.57m³/ h (is equivalent to sodium sulphate in control treatment fluid Concentration be 0.978Y (87.4g/L)).

Second concentrate of sulfur acid sodium crystal and sodium chloride crystal that the second evaporation is obtained is in low-temperature treatment tank 55 Cooling processing is carried out, temperature is 20 DEG C, and time 60min obtains the treatment fluid of sodium chloride-containing crystal.Low-temperature treatment tank 55 has Agitating paddle, revolving speed 60r/min.

The treatment fluid of the sodium chloride-containing crystal that cooling is handled be sent into third equipment for separating liquid from solid 92 (centrifuge) into After row third is separated by solid-liquid separation and elutes, 0.31m is obtained per hour³Contain NaCl 277.5g/L, Na₂SO₄ 87.4g/L、NaOH 10.2g/L、NH₃The third mother liquor of 0.0026g/L, is temporarily stored into third mother liquor tank 54, and is all returned by the 9th circulating pump 79 It is back to waste water conveyance conduit and catalyst production waste water is mixed to get waste water to be processed.Gained solid sodium chloride (is obtained per hour The sodium chloride crystalli-zation cake 440.53kg for being 1.5 mass % to water content, wherein the content of sodium sulphate is 1.5 mass % or less) It is dry in drying machine after the sodium chloride solution elution of the 277g/L equal with sodium chloride butt quality, chlorine is obtained per hour Change sodium 433.92kg (purity is 99.5 mass %), the second cleaning solution washed is recycled to second by the tenth circulating pump 80 MVR vaporising device 1.

In the present embodiment, the ammonium hydroxide 4.12m that concentration is 1.9 mass % is obtained in the first tank used for storing ammonia 51 per hour³；The The ammonium hydroxide 1.57m that concentration is 0.05 mass % is obtained in two tank used for storing ammonia 52 per hour³。

In addition, the tail gas of the 8th heat-exchanger rig 38, equipment of crystallisation by cooling 2 and the discharge of the 4th heat-exchanger rig 34 passes through vacuum pump 81 introducing tail gas absorbers 83 are absorbed, and recirculated water are connected in tail gas absorber 83, the recirculated water is in the 4th circulating pump 74 Under the action of recycled in tail gas absorber 83, while by third circulating pump 73 from circulating water pool 82 to tail gas absorber 83 Water supplement, and fresh water is added in circulating water pool 82, reduce temperature and ammonia content that water is used in the work of vacuum pump 81.The tail It is further passed through dilute sulfuric acid in aspiration tower 83, to absorb ammonia in tail gas etc..The initial phase of MVR evaporation, pass through temperature Steam for 143.3 DEG C is started.

Embodiment 2

According to the method for embodiment 1 carry out catalyst production waste water processing, unlike: to 46g/L containing NaCl, Na₂SO₄ 89g/L、NH₄Cl 15g/L、(NH₄)₂SO₄The catalyst production waste water that 29.5g/L, pH are 6.7 is handled, and is obtained Waste water to be processed in SO₄ ^2-With Cl^-Molar ratio be 1:1.46, by the 8th heat-exchanger rig 38 carry out heat exchange after it is to be processed The temperature of waste water is 102 DEG C.

The temperature of first evaporation is 95 DEG C, and pressure is -36.36kPa, evaporation capacity 4.51m³/h；The temperature of crystallisation by cooling It is -4 DEG C, time 120min；The temperature of second evaporation is 107 DEG C, pressure 0kPa, evaporation capacity 0.54m³/h；At cooling The temperature of reason is 25 DEG C, time 58min.

First equipment for separating liquid from solid 93 obtains the sulfate crystal filter cake 614.99kg of aqueous 1.5 mass % per hour, The content of middle sodium chloride is 1.5 mass % hereinafter, molten with the sodium sulphate of the 64g/L equal with sulfate crystal filter cake butt quality Liquid elution obtains sodium sulphate 605.77kg (purity is 99.4 mass %) per hour, obtains 1.39m per hour after dry³Contain NaCl 268.7g/L、Na₂SO₄ 64.4g/L、NaOH 1.15g/L、NH₃The first mother liquor (Cl of 0.44g/L^-Concentration be 4.593mol/L SO₄ ^2-Concentration be 0.4535mol/L).

Second equipment for separating liquid from solid 91 obtains the sal glauberi crystalli-zation cake 158.68kg of aqueous 55 mass % per hour, Purity is 98.3 mass %), it is evaporated with returning to first after catalyst production waste water dissolution；1.27m is obtained per hour³Concentration For NaCl 295.5g/L, Na₂SO₄ 14.4g/L、NaOH 1.26g/L、NH₃The second mother liquor of 0.48g/L.

Third equipment for separating liquid from solid 92 obtains the sodium chloride crystalli-zation cake that water content is 1.4 mass % per hour 314.32kg finally obtains sodium chloride 309.92kg per hour (purity is 99.5 mass %)；0.222m is obtained per hour³, dense Degree is NaCl 279.5g/L, Na₂SO₄ 82.2g/L、NaOH 7.2g/L、NH₃The third mother liquor of 0.0028g/L.

The ammonium hydroxide 4.51m that concentration is 1.3 mass % is obtained in first tank used for storing ammonia 51 per hour³；Second tank used for storing ammonia 52 In obtain per hour concentration be 0.05 mass % ammonium hydroxide 1.14m³。

Embodiment 3

According to the method for embodiment 1 carry out catalyst production waste water processing, unlike: to 82g/L containing NaCl, Na₂SO₄ 42g/L、NH₄Cl 36.5g/L、(NH₄)₂SO₄The catalyst production waste water that 19g/L, pH are 6.2 is handled, and is obtained Waste water to be processed in SO₄ ^2-With Cl^-Molar ratio be 1:5.20, by the 8th heat-exchanger rig 38 carry out heat exchange after it is to be processed The temperature of waste water is 107 DEG C.

The temperature of first evaporation is 100 DEG C, and pressure is -22.82kPa, evaporation capacity 3.47m³/h；The temperature of crystallisation by cooling It is 0 DEG C, time 120min；The temperature of second evaporation is 105 DEG C, and pressure is -7.02kPa, evaporation capacity 2.16m³/h；Cooling 30 DEG C of the temperature of processing, time 55min.

First equipment for separating liquid from solid 93 obtains the sulfate crystal filter cake 315.15kg of aqueous 1.4 mass % per hour, The content of middle sodium chloride is 1.5 mass % hereinafter, molten with the sodium sulphate of the 60g/L equal with sulfate crystal filter cake butt quality Liquid elution obtains sodium sulphate 310.74kg (purity is 99.5 mass %) per hour, obtains 2.71m per hour after dry³Contain NaCl 279.1g/L、Na₂SO₄ 60.3g/L、NaOH 2.2g/L、NH₃The first mother liquor of 0.30g/L (wherein contains Cl^- 4.771mol/L SO₄ ^2-0.4246mol/L)。

Second equipment for separating liquid from solid 91 obtains the sal glauberi crystalli-zation cake 278.01kg of aqueous 56 mass % per hour, Purity is 98.6 mass %), it is evaporated with returning to first after catalyst production waste water dissolution；2.49m is obtained per hour³Concentration For NaCl 304.3g/L, Na₂SO₄ 16.8g/L、NaOH 2.39g/L、NH₃The second mother liquor of 0.33g/L,.

Third equipment for separating liquid from solid 92 obtains the sodium chloride crystalli-zation cake that water content is 1.5 mass % per hour 620.36kg finally obtains sodium chloride 611.05kg per hour (purity is 99.5 mass %)；0.527m is obtained per hour³Concentration For NaCl 281g/L, Na₂SO₄ 78.5g/L、NaOH 11.3g/L、NH₃The third mother liquor of 0.0016g/L.

The ammonium hydroxide 3.47m that concentration is 2.2 mass % is obtained in first tank used for storing ammonia 51 per hour³；Second tank used for storing ammonia 52 In obtain per hour concentration be 0.038 mass % ammonium hydroxide 2.16m³。

The preferred embodiment of the present invention has been described above in detail, and still, the present invention is not limited thereto.In skill of the invention In art conception range, can with various simple variants of the technical solution of the present invention are made, including each technical characteristic with it is any its Its suitable method is combined, and it should also be regarded as the disclosure of the present invention for these simple variants and combination, is belonged to Protection scope of the present invention.

Claims

1. a kind of processing method of catalyst production waste water, the catalyst production waste water contain NH₄ ⁺、SO₄ ^2-、Cl^-And Na⁺, special Sign is that this approach includes the following steps,

1) waste water to be processed is subjected to the first evaporation, obtains the first concentrate of the first steam containing ammonia and sulfur acid sodium crystal, institute It states waste water to be processed and contains the catalyst production waste water；

2) the first concentrate of the sulfur acid sodium crystal is carried out first to be separated by solid-liquid separation, and is separated by solid-liquid separation obtained liquid for first Crystallisation by cooling is mutually carried out, the crystal solution of sulfur acid sodium crystal is obtained；

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

4) the second concentrate of the sodium chloride-containing crystal is subjected to cooling processing, obtains the treatment fluid of sodium chloride-containing crystal；

5) treatment fluid is subjected to third separation of solid and liquid；

Wherein, before waste water to be processed is carried out the first evaporation, the pH value for adjusting the waste water to be processed is greater than 9；

Relative to the SO contained in waste water to be processed described in 1mol₄ ^2-, the Cl that contains in the waste water to be processed^-For 14mol or less；

First evaporation is precipitated sodium chloride crystallization.

2. according to the method described in claim 1, wherein, the waste water to be processed is the catalyst production waste water；Alternatively, institute Stating waste water to be processed is that the catalyst production waste water is mixed at least part of of liquid phase that the third is separated by solid-liquid separation Liquid；

Preferably, described first it is separated by solid-liquid separation SO in obtained liquid phase₄ ^2-Concentration be 0.01mol/L or more, Cl^-Concentration be 5.2mol/L following；

Preferably, described first it is separated by solid-liquid separation SO in obtained liquid phase₄ ^2-Concentration be 0.01mol/L or more, Cl^-Concentration be 5.0mol/L following；

Preferably, the SO contained in obtained liquid phase is separated by solid-liquid separation relative to described in 1mol second₄ ^2-, described second is separated by solid-liquid separation The Cl contained in obtained liquid phase^-For 7.15mol or more；

Preferably, before waste water to be processed is carried out the first evaporation, the pH value for adjusting the waste water to be processed is greater than 10.8；

Preferably, pH value is adjusted to carry out using NaOH.

3. according to the method described in claim 1, wherein, first evaporation makes the concentration of sodium chloride in first concentrate For X or less, wherein X is under conditions of the first evaporation, when sodium sulphate and sodium chloride reach saturation in first concentrate The concentration of sodium chloride；

Preferably, first evaporation makes the concentration 0.95X-0.999X of sodium chloride in first concentrate；

Preferably, before the crystallisation by cooling, the described first concentration for being separated by solid-liquid separation sodium chloride in obtained liquid phase is adjusted, is made Described first is separated by solid-liquid separation SO in obtained liquid phase₄ ^2-Concentration be 0.01mol/L or more, Cl^-Concentration be 5.2mol/L with Under；

Preferably, it adjusts described first and is separated by solid-liquid separation the concentration of sodium chloride in obtained liquid phase by mixing the catalyst production The liquid phase that waste water, the cleaning solution for washing sodium sulfate crystal and/or third are separated by solid-liquid separation carries out.

4. method described in any one of -3 according to claim 1, wherein the crystallisation by cooling obtains only brilliant containing sodium sulphate The crystal solution of body；Alternatively, the crystallisation by cooling obtains the crystal solution containing sodium sulfate crystal and sodium chloride crystal；

Preferably, obtained solid phase is separated by solid-liquid separation by second be back to the first evaporation.

5. method described in any one of -4 according to claim 1, wherein second evaporation makes sulfuric acid in the treatment fluid The concentration of sodium is Y or less, wherein Y is under conditions of cooling processing, and sodium sulphate and sodium chloride reach full in the treatment fluid With when sodium sulphate concentration；

Preferably, second evaporation makes the concentration 0.9Y-0.99Y of sodium sulphate in the treatment fluid.

6. method described in any one of -4 according to claim 1, wherein the condition of first evaporation includes: that temperature is 35 DEG C or more, pressure is -98kPa or more；

Preferably, it is 75 DEG C~130 DEG C that the condition of first evaporation, which includes: temperature, and pressure is -73kPa~117kPa；

Preferably, it is 85 DEG C~130 DEG C that the condition of first evaporation, which includes: temperature, and pressure is -58kPa~117kPa；

Preferably, it is 95 DEG C~110 DEG C that the condition of first evaporation, which includes: temperature, and pressure is -37kPa~12kPa；

Preferably, first evaporation is carried out by MVR vaporising device.

7. method described in any one of -4 according to claim 1, wherein the condition of the crystallisation by cooling include: temperature be - 21.7 DEG C~17.5 DEG C, preferably -20 DEG C~5 DEG C, more preferably -10 DEG C~5 DEG C, further preferably -10 DEG C~0 DEG C；

Preferably, the condition of the crystallisation by cooling include: the time be 5min or more, preferably 60min~180min, more preferably 90min~150min.

8. method described in any one of -4 according to claim 1, wherein the condition of second evaporation includes: that temperature is 35 DEG C or more, pressure is -98kPa or more；

Preferably, it is 45 DEG C~175 DEG C that the condition of second evaporation, which includes: temperature, and pressure is -95kPa~653kPa；

Preferably, it is 60 DEG C~160 DEG C that the condition of second evaporation, which includes: temperature, and pressure is -87kPa~414kPa；

Preferably, it is 75 DEG C~150 DEG C that the condition of second evaporation, which includes: temperature, and pressure is -73kPa~292kPa；

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

Preferably, it is 95 DEG C~110 DEG C that the condition of second evaporation, which includes: temperature, and pressure is -37kPa~12kPa；

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

9. method described in any one of -4 according to claim 1, wherein the condition of the cooling processing includes: that temperature is 13 DEG C~100 DEG C, preferably 15 DEG C~45 DEG C, more preferably 15 DEG C~35 DEG C, further preferably 17.9 DEG C~35 DEG C；

Preferably, it is described cooling processing condition include: the time be 5min or more, preferably 5min~120min, more preferably 45min~90min.

10. method described in any one of -4 according to claim 1, wherein steamed the waste water to be processed is carried out first Before hair, the waste water to be processed and first steam containing ammonia are subjected to the first heat exchange, and obtain the first ammonium hydroxide；

Preferably, before being separated by solid-liquid separation obtained liquid phase by described first and carrying out crystallisation by cooling, described first is separated by solid-liquid separation Obtained liquid phase and described second is separated by solid-liquid separation obtained liquid phase and carries out the second heat exchange；

Preferably, before being separated by solid-liquid separation obtained liquid phase by described second and carrying out the second evaporation, by second steam containing ammonia It is separated by solid-liquid separation obtained liquid phase with described second and carries out third heat exchange, and obtains the second ammonium hydroxide.

11. method described in any one of -10 according to claim 1, this method further includes by the sulfur acid sodium crystal First concentrate obtains sodium sulfate crystal after first is separated by solid-liquid separation；

Preferably, this method further includes that the crystal solution of the sulfur acid sodium crystal is obtained sodium sulphate after second is separated by solid-liquid separation Crystal；

Preferably, when being separated by solid-liquid separation obtained sodium sulfate crystal as when product for second, this method further includes to obtained sulphur Sour sodium crystal is washed.

12. method described in any one of -10 according to claim 1, this method further includes by the sodium chloride-containing crystal Treatment fluid obtains sodium chloride crystal after third is separated by solid-liquid separation；

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

13. method described in any one of -10 according to claim 1, wherein NH in the catalyst production waste water₄ ⁺For 8mg/L or more, SO₄ ^2-For 1g/L or more, Cl^-For 970mg/L or more, Na⁺For 510mg/L or more；

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

Preferably, this method further includes that the catalyst production waste water is cleaned and is concentrated.