CN109422402A

CN109422402A - The processing method of catalyst production waste water

Info

Publication number: CN109422402A
Application number: CN201710752083.3A
Authority: CN
Inventors: 殷喜平; 李叶; 刘志坚; 杨凌
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: CN109422402B

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 approach includes the following steps, and 1) by the first evaporation of waste water to be processed progress, the first steam containing ammonia and the first concentrate are obtained, the waste water to be processed contains the catalyst production waste water；2) first concentrate is subjected to crystallisation by cooling, obtains the crystal solution of sulfur acid sodium crystal；3) crystal solution of the sulfur acid sodium crystal is carried out first to be separated by solid-liquid separation, and is separated by solid-liquid separation the second evaporation of each effect evaporator progress that obtained liquid phase is passed through multi-effect evaporating device for first, obtain the second concentrate of the second steam containing ammonia and sodium chloride-containing crystal；4) the second concentrate of the sodium chloride-containing crystal second is carried out to be separated by solid-liquid separation.Ammonium and sodium sulphate, sodium chloride in waste water can be separately recovered in this method, farthest recycle the resource in waste water.

Description

The processing method of 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, the present invention provides a kind of processing method of catalyst production waste water, catalyst 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 steam containing ammonia and the first concentrate, it is described to be processed useless Water contains the catalyst production waste water；

2) first concentrate is subjected to crystallisation by cooling, obtains the crystal solution of sulfur acid sodium crystal；

3) crystal solution 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 Each effect evaporator for being mutually passed through multi-effect evaporating device carries out the second evaporation, obtains the of the second steam containing ammonia and sodium chloride-containing crystal Two concentrates；

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

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；Institute State SO in the first concentrate₄ ^2-Concentration be 0.01mol/L or more, Cl^-Concentration be 5.2mol/L or less；Second evaporation Sulfate crystal is precipitated.

Through the above technical solutions, for NH is contained₄ ⁺、SO₄ ^2-、Cl^-And Na⁺Catalyst production waste water, by advance will be to After the pH value of processing waste water is adjusted to specific range, carries out the first evaporation and obtain denseer ammonium hydroxide, recycle crystallisation by cooling point From sodium sulfate crystal is obtained, sodium chloride crystal and diluter ammonium hydroxide are then obtained by the second evaporation.This method can obtain respectively To the sodium sulphate and sodium chloride of high-purity, difficulty during avoiding mixed salt processing and recycling, be completed at the same time separation of ammonia and The process of salt, and using heat exchange method while making waste water heating and steam cooling containing ammonia, it is not necessarily to condenser, rationally utilizes steaming Heat during hair, it is energy saving, reduce cost for wastewater treatment, the ammonium in waste water recycle in the form of ammonium hydroxide, sodium chloride with Sodium sulphate is recycled respectively with crystal form, and whole process does not have waste residue and liquid generation, realizes the purpose to turn waste into wealth.

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, multi-effect evaporating device 60, third pH value measuring device

2, equipment of crystallisation by cooling 70, the 11st circulating pump

3, MVR vaporising device 71, first circulation pump

31, the first heat-exchanger rig 72, second circulation pump

32, the second heat-exchanger rig 73, third circulating pump

33, third heat-exchanger rig 74, the 4th circulating pump

34, the 4th heat-exchanger rig 75, the 5th circulating pump

36, the 6th heat-exchanger rig 76, the 6th circulating pump

37, the 7th heat-exchanger rig 77, the 7th circulating pump

38, the 8th heat-exchanger rig 78, the 8th circulating pump

30, the tenth heat-exchanger rig 79, the 9th circulating pump

51, the first tank used for storing ammonia 80, the tenth circulating pump

52, the second tank used for storing ammonia 81, vacuum pump

53, the first mother liquor tank 82, circulating water pool

54, the second mother liquor tank 83, tail gas absorber

55, brilliant liquid collecting tank 91, the first equipment for separating liquid from solid

61, the first pH value measuring device 92, the second equipment for separating liquid from solid

62, the second pH value measuring device 101, the first compressor

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,

Preferably, the waste water to be processed is the catalyst production waste water；Alternatively, the waste water to be processed contain it is described Catalyst production waste water and described second is separated by solid-liquid separation obtained liquid phase.

It is highly preferred that the waste water to be processed is that the catalyst production waste water and described second are separated by solid-liquid separation obtained liquid 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 addition, in the present invention, from the point of view of the treatment effeciency for improving waste water, containing in first concentrate SO₄ ^2-It is further excellent for 0.01mol/L or more, more preferably 0.07mol/L or more, further preferably 0.1mol/L or more It is selected as 0.2mol/L or more, particularly preferably 0.3mol/L or more, such as can be 0.5-1mol/L, can be 0.6- 0.7mol/L.Also, Cl in first concentrate^-Concentration be 5.2mol/L hereinafter, preferably 4.5mol/L hereinafter, more excellent Be selected as 3mol/L hereinafter, preferably 0.01mol/L or more, more preferably 0.05mol/L or more, more preferably 0.1mol/L with On, further preferably 0.5mol/L or more is still more preferably 1mol/L or more, still more preferably for 2mol/L with On, such as can be 2-3mol/L.By by the SO in the first concentrate₄ ^2-、Cl^-Concentration control in above range, can make Sodium sulphate is precipitated in crystallisation by cooling and sodium chloride is not precipitated, to achieve the purpose that efficiently separate sodium sulphate.

As the SO contained in first concentrate₄ ^2-Specific example can be with are as follows: 0.01mol/L, 0.03mol/L, 0.05mol/L、0.1mol/L、0.3mol/L、0.4mol/L、0.5mol/L、0.6mol/L、0.7mol/L、0.8mol/L、 0.9mol/L、1mol/L、1.2mol/L、1.4mol/L、1.5mol/L、1.8mol/L、2mol/L、2.2mol/L、2.5mol/L、 2.8mol/L or 3mol/L etc..

As the Cl contained in first concentrate^-Specific example can be with are as follows: 0.05mol/L, 0.1mol/L, 0.3mol/L、0.5mol/L、0.8mol/L、1mol/L、1.3mol/L、1.5mol/L、1.6mol/L、1.7mol/L、1.8mol/ L、2mol/L、2.2mol/L、2.4mol/L、2.5mol/L、2.8mol/L、3mol/L、3.2mol/L、3.5mol/L、3.8mol/ L, 4mol/L, 4.2mol/L, 4.5mol/L, 4.8mol/L or 5mol/L etc..

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 catalyst production waste water is separated by solid-liquid separation obtained liquid phase with described second 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, 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 purpose of first evaporation is to make Waste water concentrating to be processed, while obtaining denseer ammonium hydroxide, The concentration of ion is improved, to improve the eduction rate of crystallisation by cooling, there is no particular limitation for the degree that first evaporation carries out, It can according to need and selected with the ingredient of waste water to be processed, meet requirement of the crystallisation by cooling to the first concentrate.Example It such as can control evaporation and only obtain a small amount of steam containing ammonia, to obtain the higher ammonium hydroxide of concentration；It can also be evaporated by control It sufficiently carries out, waste water to be processed is concentrated sufficiently, convenient for the progress of subsequent crystallisation by cooling.Preferably, first evaporation In do not make sodium chloride crystallization be precipitated.

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 MVR vaporising device 3 It carries out.In the present invention, in the case where carrying out the first evaporation using multi-effect evaporating device, when using fair current or adverse current feeding, the The condition of one evaporation refers to the evaporation conditions of the last 1st effective evaporator of multi-effect evaporating device；When being fed using advection, first steams The condition of hair includes the evaporation conditions of each effect evaporator of multi-effect evaporating device.

According to the present invention, the condition of first evaporation can according to need appropriate selection, and reaching keeps waste water to be processed dense The purpose of contracting.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 improve the efficiency of evaporation, it is preferable that first evaporation conditions may include: temperature be 75 DEG C~130 DEG C, pressure be- 73kPa~117kPa；Preferably, it is described first evaporation condition include: temperature be 85 DEG C~130 DEG C, pressure be -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；It is excellent Selection of land, it is 100 DEG C~107 DEG C that the condition of first evaporation, which includes: temperature, and pressure is -23kPa~0kPa.

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

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.

In the present invention, the carry out degree of first evaporation is in such a way that the first evaporation of monitoring obtains the concentration of liquid It carries out, specifically, the concentration for obtaining liquid by the first evaporation of control makes the first evaporation not make chlorination in above-mentioned range Sodium crystallization is precipitated.Here the first evaporation obtains the concentration of liquid, is monitored by way of measuring density, specifically be can be used Densitometer 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, for pH value the adjusting upper limit there is no limit, such as can be 14 hereinafter, preferably 13.5 with Under, more preferable 13 hereinafter, further preferably 12 hereinafter, still more preferably be 11.5 or less.By making the first evaporation upper It states and is carried out under pH value, the evaporation of ammonia can be promoted, obtain the higher ammonium hydroxide of concentration, and convenient for obtaining height in subsequent crystallization The sodium sulphate and sodium chloride crystal of purity.

Before waste water to be processed is carried out the first evaporation, the specific example for adjusting the pH value of the waste water to be processed can be with Enumerate: 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. second is separated by solid-liquid separation obtained liquid phase) in addition, the second mother liquor, it is also preferred that using the In addition two mother liquors can add NaOH as the alkaline matter again.

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 are carried out in MVR vaporising device 3, are being incited somebody to action Waste water to be processed is sent into before MVR vaporising device 3, by will import in the pipeline of waste water to be processed feeding MVR vaporising device 3 The aqueous solution containing alkaline matter and mixing, Lai Jinhang pH value are adjusted, and pass through the first pH value measuring device after adjustment 61 and 60 pairs of third pH value measuring device adjust after pH value measure.

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 pass through the 8th heat-exchanger rig 38 and the first steam heat-exchanging containing ammonia again.By the first heat exchange, obtains the first ammonium hydroxide and be stored in In first tank used for storing ammonia 51, while waste water to be processed being made to be warming up to 74 DEG C~129 DEG C, preferably 94 DEG C~109 DEG C, is convenient for evaporation Progress.

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.

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 strength of fluid in the MVR vaporising device 3, the ammonia content in liquid is reduced, it is excellent Choosing by after the MVR vaporising device 3 evaporation partially liq (namely the liquid inside MVR vaporising device, hereinafter Referred to as first circulation liquid) it again returns in the MVR vaporising device 3 and evaporates after heating.It is above-mentioned to return to the first circulation liquid Process to the MVR vaporising device 3 is preferably, to be processed useless before the first circulation liquid and the first heat exchange are completed It is again returned in MVR vaporising device 3 after water mixing, for example, can be returned to the first circulation liquid by the 5th circulating pump 75 It mixes into the waste water conveyance conduit between the first heat-exchanger rig 31 and the 8th heat-exchanger rig 38 with waste water to be processed, is then passing through It crosses second of pH value to adjust and then carry out heat exchange by the 8th heat-exchanger rig 38, and passes through third pH value measurement dress 60 monitoring pH value are set, are finally sent into the MVR vaporising device 3.Here, first reflux ratio refers to: regurgitant volume and feeding Total amount of liquid in MVR vaporising device 3 subtracts the ratio of regurgitant volume.The reflux ratio can suitably be set according to evaporation capacity It is fixed, the water and ammonia of requirement can be evaporated to guarantee MVR vaporising device 3 under given evaporating temperature.The evaporation Reflux ratio for example 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 purpose of the crystallisation by cooling is that sodium sulphate is precipitated, and sodium chloride is not precipitated, so as to Sodium sulphate is separated from catalyst production waste water well.Sodium sulphate only is precipitated in the crystallisation by cooling, it is not excluded that sulfuric acid The sodium chloride of sodium crystallization entrainment or adsorption.In the present invention, it is preferred to which the content of sodium sulphate is in obtained sodium sulfate crystal 92 mass % or more, more preferably 96 mass % or more, further preferably 98 mass % or more, it is to be understood that described The amount of obtained sodium sulfate crystal is with butt meter.It can be with when the content of sodium sulphate is above range in obtained sodium sulfate crystal Think only sodium sulphate precipitation.

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 sulphate and sodium chloride concentration, can be improved the eduction rate of sodium sulphate.

In the present invention, there is no particular limitation can according to need appropriate selection for the condition of the crystallisation by cooling, reaches The effect that the sulfate crystal is precipitated.The condition of the crystallisation by cooling may include: that temperature is -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 (in terms of the residence time in equipment of crystallisation by cooling 2) be 5min or more, preferably 60min~180min, more preferably 90min~150min, further preferably 120min~150min.By controlling the condition of crystallisation by cooling in above range, Sodium sulphate can be made sufficiently to be precipitated.

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 concentrate, makes the purpose of sulfate crystal precipitation, it is preferred to use even Continuous crystallisation by cooling mode carries out.The crystallisation by cooling sodium sulphate can use various cooling crystallizing equipments commonly used in the art It carries out, such as can be using the continuous cooling crystallizer with external cooling heat exchanger, or uses the knot with cooling-part Brilliant tank carries out, such as equipment of crystallisation by cooling 2.The cooling-part can make equipment of crystallisation by cooling by way of importing cooling medium Condition needed for the first interior concentrate is cooled to crystallisation by cooling.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 concentrate, sodium sulphate therein can be made sufficiently to analyse Out, increase 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, is prevented The crystal grain and impeller high velocity impact only recycled in magma generates a large amount of secondary nucleus, and the circulating pump is preferably the centrifugation of the slow-speed of revolution Pump, more preferably 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, can make in crystallisation by cooling sodium sulphate be sufficiently precipitated and Sodium chloride is not precipitated, to achieve the purpose that separating-purifying sodium sulphate.

According to the present invention, before the first concentrate is carried out crystallisation by cooling, as needed, the first concentrate is preferably adjusted The concentration of middle sodium chloride, the concentration X or less of sodium chloride in the crystal solution for obtaining crystallisation by cooling, wherein X is in crystallisation by cooling Under conditions of, the concentration of sodium chloride when sodium sulphate and sodium chloride reach saturation in crystal solution.By by chlorine in the first concentrate The concentration for changing sodium is adjusted to above range, it is ensured that sodium chloride is not precipitated in crystallisation by cooling.Preferably, make in the crystal solution The concentration of sodium chloride is 0.95X-0.999X.The method that the sodium chloride concentration is adjusted can be using the second of mixing debita spissitudo The mode of the other waste liquids generated in mother liquor, water, the catalyst production waste water and/or treatment process etc. carries out, as long as making The concentration of sodium chloride is adjusted in above range in one concentrate.In order to avoid introducing more liquid, it is preferable that adjust the The concentration of sodium chloride passes through the second mother liquor of mixing, the catalyst production waste water and/or elution sodium sulfate crystal in one concentrate Cleaning solution afterwards carries out.By the way that the concentration of sodium chloride in the first concentrate is adjusted to above range, crystallisation by cooling mistake is avoided The precipitation of journey sodium chloride improves the purity that sodium sulphate is precipitated in crystallisation by cooling process, improves the efficiency of crystallisation by cooling.

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 waste water to be processed after return to equipment of crystallisation by cooling 2 in cooled down again Crystallization.It is above-mentioned for example to pump cooling circulation liquid by second circulation back to the process that the equipment of crystallisation by cooling 2 crystallizes Before cooling circulation liquid is returned to the 6th heat-exchanger rig 36 by 72, the crystallisation by cooling is again introduced into after mixing with the first concentrate Device 2 carries out crystallisation by cooling.The back amount of the cooling circulation liquid can be defined by the recycle ratio of crystallisation by cooling, described cold But the recycle ratio crystallized refers to: the total amount of liquid in internal circulating load and feeding equipment of crystallisation by cooling subtracts the ratio of internal circulating load.It is described Recycle ratio can be appropriately configured according to the degree of supersaturation of sodium sulphate in the equipment of crystallisation by cooling 2, to guarantee sodium sulphate knot Brilliant granularity.In order to control the size distribution of crystal obtained by crystallisation by cooling, the content of fine grain is reduced, preferably control degree of supersaturation Less than 1.5g/L, more preferably less than 1g/L.

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

According to the present invention, first separation of solid and liquid can use the first equipment for separating liquid from solid (for example, centrifuge, belt Filter, flame filter press etc.) 91 progress.After described first is separated by solid-liquid separation, the first equipment for separating liquid from solid 91 is obtained first female Liquid is temporarily stored into the first mother liquor tank 53, and can be sent into multi-effect evaporating device 1 by the 6th circulating pump 76 and be carried out the second evaporation.Separately Outside, the impurity such as certain chloride ion, free ammonia, hydroxide ion can be adsorbed by being difficult to avoid that on the sodium sulfate crystal obtained, in order to The impurity for removing absorption reduces the peculiar smell of solid salt, reduces corrosivity, improves the purity of the crystal, it is preferable that the sulfuric acid Sodium crystal water or metabisulfite solution carry out the first washing, can be dried when needing to obtain anhydrous sodium sulfate.

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 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.First mode of washing preferably elutes, preferably in solid-liquid point It is eluted from after.There is no particular limitation for the number of the washing, can be 1 time or more, in order to obtain the sulphur of higher purity Sour sodium crystal, preferably 2-4 times.It is preferable to use aqueous sodium persulfate solution, (concentration of the aqueous sodium persulfate solution is preferred for first washing Sodium sulphate is dense in the aqueous solution for reaching saturation simultaneously for sodium chloride at the temperature corresponding to sodium sulfate crystal to be washed and sodium sulphate Degree) it carries out.For the liquid that washing generates, equipment of crystallisation by cooling 2 is preferably returned it to, such as the 8th circulating pump can be passed through 78 be back to the 6th heat-exchanger rig 36 before mixed with the first concentrate after, return again to equipment of crystallisation by cooling 2.

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 first mother liquor, the first concentrate is preferably being subjected to crystallisation by cooling Before, the first mother liquor and the first concentrate 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 first mother liquor and the first concentrate are passed through into the second heat-exchanger rig 32 respectively, both make to carry out heat exchange, to make the The temperature of one concentrate reduces the progress for being convenient for crystallisation by cooling, while increases the temperature of the first mother liquor convenient for the second evaporation.It is logical It crosses after the second heat-exchanger rig 32 carries out the second heat exchange, the temperature of the first concentrate 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 concentrate and freezing liquid are subjected to the second heat Exchange.A preferred embodiment according to the present invention, the second heat exchange of first concentrate and freezing liquid pass through the Six heat-exchanger rigs 36 carry out, and specifically, freezing liquid and the first concentrate are passed through the 6th heat-exchanger rig 36 respectively, carry out the two Heat exchange, so that making the temperature of the first concentrate reduces the progress for being convenient for crystallisation by cooling.The freezing liquid can use this field Conventionally used for the freezing liquid of cooling, as long as the temperature of the first concentrate 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, there is no particular limitation for each effect evaporator of the multi-effect evaporating device 1, can be normal by this field Advise the various evaporators composition used.Such as can selected from downward film evaporator, film-rising evaporator, scraper-type evaporator, in It entreats in circulating tube type multi-effect evaporator, basket evaporator, external heating type evaporator, forced-circulation evaporator and Liewen evaporator It is one or more.Wherein, preferably forced-circulation evaporator, external heating type evaporator.Each effect of the multi-effect evaporating device 1 is steamed Hair device respectively by heating room and vaporization chamber form, can also as needed comprising other evaporation accessories, such as make liquid foam into The demister of one step separation, the vacuum plant the etc. when condenser and decompression operation that condense secondary steam all.It is described more There is no particular limitation for the evaporator quantity that effect vaporising device 1 contains, and can be 2 effects or more, preferably 2-5 is imitated, more preferably 2-4 effect.When in the present invention, using fair current or adverse current feeding, second evaporation condition refer to multi-effect evaporating device last Imitate the evaporation conditions of evaporator；When being fed using advection, the condition of the second evaporation includes each effect evaporator of multi-effect evaporating device Evaporation conditions.

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.It is described second evaporation condition may include: temperature be 17.5 DEG C or more, pressure be- 101kPa or more；Preferably, it is described second evaporation condition include: temperature be 35 DEG C~110 DEG C, pressure be -98kPa~ 12kPa；Preferably, it is 45 DEG C~110 DEG C that the condition of second evaporation, which includes: temperature, and pressure is -95kPa~12kPa；It is excellent Selection of land, it is 50 DEG C~110 DEG C that the condition of second evaporation, which includes: temperature, and pressure is -93kPa~12kPa.

In the present invention, in the second evaporation, 5 DEG C of evaporating temperature difference of adjacent two-effect evaporation device or more, preferably 5 DEG C~30 DEG C, more preferable 10 DEG C~20 DEG C.

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

In addition, ability and wastewater flow rate to be processed that the evaporation capacity of the second evaporation can be handled according to equipment suitably select, It such as can be 0.1m³/ h or more (such as 0.1m³/ h~500m³/h).It, can be with by carrying out the second evaporation under the above conditions While guaranteeing sodium chloride crystallization, sodium sulphate is not crystallized, the purity for the sodium chloride crystal that thereby may be ensured that.

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

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

A preferred embodiment according to the present invention, second evaporation process carry out in multi-effect evaporating device 1, The multi-effect evaporating device 1 is by 1st effective evaporator 1a, 2nd effect evaporator 1b, third effect evaporator 1c and fourth evaporator 1d composition.First mother liquor is successively passed through in each effect evaporator of the multi-effect evaporating device 1 and is evaporated to obtain containing chlorine Change the second concentrate of sodium crystal.The second steam containing ammonia that preceding 1st effective evaporator is obtained is passed through in rear 1st effective evaporator, and To the second ammonium hydroxide.It is passed through heating steam (life steam i.e. commonly used in the art) in 1st effective evaporator 1a, heats steam The condensation water obtained after being condensed in 1st effective evaporator 1a.

In order to guarantee the available sodium chloride crystal of the second evaporation process, need further satisfaction relative to described in 1mol One is separated by solid-liquid separation the SO contained in obtained liquid phase₄ ^2-, described first is separated by solid-liquid separation the Cl contained in obtained liquid phase^-For 9.5mol or more, preferably 10mol or more, preferably 50mol hereinafter, more preferably 40mol, further preferably 30mol with Under, for example, 10-20mol.By by SO₄ ^2-And Cl^-Molar ratio control in above range, can be obtained by the second evaporation Pure sodium chloride crystal 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 the second concentrate for containing only sodium chloride crystal is unable to get, although at this moment It can make dissolution of crystals by adding the modes such as water in the second concentrate, but will affect the efficiency of wastewater treatment.Therefore described The carry out degree of second evaporation is not preferably so that sodium sulfate crystal crystallizes precipitation, that is to say, that second evaporation makes the In two concentrates the concentration of sodium sulphate be Y or less (wherein, Y be under conditions of the second evaporation, in the second concentrate sodium sulphate and The concentration of sodium sulphate when sodium chloride reaches saturation).From in the second evaporization process, make sodium chloride be precipitated as far as possible and sodium sulphate not The viewpoint of precipitation considers, it is preferable that second evaporation makes the concentration 0.9Y-0.99Y of sodium sulphate in the second concentrate, 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 sodium sulphate is not precipitated, and pure sodium chloride crystal is arrived in final separation.By as far as possible Sodium chloride is crystallized in two evaporations, waste water treatment efficiency can be improved, it is energy saving.

In the present invention, the carry out degree of second evaporation is in such a way that the second evaporation of monitoring obtains the concentration of liquid It carries out, specifically, the concentration for obtaining liquid by the second evaporation of control makes the second evaporation not make sodium sulphate knot in above range Partial crystallization goes out.Here the second 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, in order to make full use of the second evaporation to obtain the second liquid of steam condensation containing ammonia in heat, preferably Before the first mother liquor is sent into multi-effect evaporating device 1, the first mother liquor and the second steam condensation containing ammonia liquid are subjected to third Heat exchange.

The third heat of a preferred embodiment according to the present invention, the first mother liquor and the second steam condensation containing ammonia liquid is handed over It changes and is carried out by the 4th heat-exchanger rig 34, the first mother liquor and the second steam condensation containing ammonia liquid are passed through into the 4th heat-exchanger rig respectively 34, make the heating of the first mother liquor convenient for evaporation, while the second liquid of steam condensation containing ammonia being made to cool down to obtain the second ammonium hydroxide, is stored in second In tank used for storing ammonia 52.After 34 heat exchange of the 4th heat-exchanger rig, first mother liquor is warming up to 34 DEG C~109 DEG C, It is preferred that 44 DEG C~109 DEG C.

, according to the invention it is preferred to the second steam containing ammonia that the last 1st effective evaporator of multi-effect evaporating device 1 is obtained and cooling Water carries out third heat exchange, obtains the second ammonium hydroxide.The second steam containing ammonia that the last 1st effective evaporator of multi-effect evaporating device obtains with The third heat exchange of cooling water (such as using catalyst production waste water as cooling water) is carried out by third heat-exchanger rig 33, is obtained To the second ammonium hydroxide merging be stored in the second tank used for storing ammonia 52.

, according to the invention it is preferred to will heat condensation water that steam is obtained in the 1st effective evaporator of multi-effect evaporating device 1 with Second cleaning solution carries out heat exchange, and above-mentioned heat exchange is carried out by the 7th heat-exchanger rig 37.

There is no particular limitation for the third heat-exchanger rig 33, the 4th heat-exchanger rig 34 and the 7th heat-exchanger rig 37, can be with Using various heat exchangers commonly used in the art, achieve the purpose that the second steam containing ammonia carries out heat exchange i.e. with the first mother liquor It can.It specifically, can be 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, it is double for can choose material Phase stainless steel, titanium or titanium alloy, Hastelloy heat exchanger, the heat exchanger containing plastic material can be selected when temperature is lower. Preferably, two phase stainless steel plate heat exchanger is selected.

A preferred embodiment according to the present invention, before the first mother liquor is passed through multi-effect evaporating device 1, monitoring The pH value of first mother liquor, such as the pH value by the second pH value measuring device 62 the first mother liquor of monitoring.

According to the present invention, this method further includes crystallizing the second concentrate of the sodium chloride-containing crystal in crystallization apparatus Obtain the magma of sodium chloride-containing crystal.At this point, the evaporation conditions of second evaporation need to meet makes chlorination in crystallization apparatus Sodium crystallization and purpose that sodium sulphate is not precipitated.There is no particular limitation for the crystallization apparatus, such as can be brilliant flow container, crystalline substance Liquid collecting tank, band stir thickener or without stirring thickeners etc..A preferred embodiment according to the present invention, the knot Crystalline substance carries out in brilliant liquid collecting tank 55.There is no particular limitation for the condition of the crystallization, such as may include: that crystallization temperature is 17.5 DEG C~107 DEG C, preferably 44 DEG C~107 DEG C.In order to fully ensure that the effect of crystallization, crystallization time can for 5min~ For 24 hours, preferably 5min~30min.

According to the present invention, the crystallization process of the second concentrate of the sodium chloride-containing crystal can also be with crystallizer It is carried out in multi-effect evaporating device (such as forced-circulation evaporation crystallizer), the temperature crystallized at this time is the temperature of corresponding second evaporation Degree.According to the present invention, when being crystallized using individual crystallization apparatus, need to be further ensured that the sulfuric acid for crystallizing and not making (i.e. sodium sulphate is not up to supersaturation) is precipitated in sodium crystallization, it is preferable that second evaporation makes sodium sulphate in second concentrate Concentration be Y or less, wherein Y be under conditions of the crystallization, sodium chloride and sodium sulphate reach saturation in the second concentrate When sodium sulphate concentration.

According to the present invention, second separation of solid and liquid can pass through the second equipment for separating liquid from solid (for example, centrifuge, belt Filter, flame filter press etc.) 92 progress.After described second is separated by solid-liquid separation, the second equipment for separating liquid from solid 92 is obtained second female Liquid (i.e. second is separated by solid-liquid separation obtained liquid phase) returns to MVR device 3 and is evaporated again, can specifically pass through the 9th circulating pump 79 Before second mother liquor is adjusted back to second of pH value.In addition, be difficult to avoid that on obtained sodium chloride crystal can adsorb it is certain The impurity such as sulfate ion, free ammonia, hydroxide ion reduce the peculiar smell of solid salt to remove the impurity of absorption, reduce rotten Corrosion 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 the second washing and drying.In order to avoid the dissolution of sodium chloride crystal in washing process, it is preferable that the sodium chloride is brilliant Body is washed with sodium-chloride water solution.It is highly preferred that the concentration of the sodium-chloride water solution is preferably brilliant in sodium chloride 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 body.

It is separated by solid-liquid separation the mode washed with second as above-mentioned second, there is no particular limitation, and ability can be used for example The elutriation apparatus and solid-liquid separating equipment of domain routine, which combine, to carry out, can also be in the equipment for separating liquid from solid such as band filter of segmentation Upper progress.Second washing includes eluriating and/or eluting, and second mode of washing is preferably first eluriated to be drenched again It washes.For above-mentioned elutriation and elution, there is no particular limitation, can be carried out by the method for this field routine.The elutriation and leaching There is no particular limitation for the number washed, and can be 1 time or more, in order to obtain the sodium chloride crystal of higher purity, preferably 2-4 It is secondary.During elutriation, it can be used when doing elutriation liquid using the cleaning solution of the second washing recycling with circulated in countercurrent.Carry out the elutriation Before, carried out preferably by way of sedimentation tentatively be separated by solid-liquid separation obtain sodium chloride-containing crystal slurries (content liquid be 35 matter Measure % or less).During elutriation, relative to the slurries of 1 parts by weight sodium chloride-containing crystal, eluriating the liquid used is 1-20 Parts by weight.It is preferable to use sodium-chloride water solution, (concentration of the sodium-chloride water solution is preferably in sodium chloride crystal to be washed for elution Sodium chloride and sodium sulphate reach the concentration of sodium chloride in the aqueous solution of saturation simultaneously at corresponding temperature) it carries out.In order to further The effect eluriated is improved, obtains the higher sodium chloride crystal of purity, in preferred situation, the leacheate that elution obtains can be used It is eluriated.For the liquid that washing generates, the catalyst production waste water eluriates liquid and is back to the pH value tune before the first evaporation Before section, other cleaning solutions are back to multi-effect evaporating device 1.

A preferred embodiment according to the present invention, by the second concentrate of sodium chloride-containing crystal, by settle into After the preliminary separation of solid and liquid of row, the liquid obtained when with subsequent wash sodium chloride crystal is eluriated in tank at another to be eluriated, then It is separated by solid-liquid separation equipment for separating liquid from solid is sent by the slurries eluriated, the crystal being separated by solid-liquid separation uses aqueous sodium chloride again (concentration of the sodium-chloride water solution is that sodium chloride and sodium sulphate reach simultaneously at the temperature corresponding to sodium chloride crystal to be washed to liquid The concentration of sodium chloride in the aqueous solution of saturation) it is eluted, and obtained liquid will be eluted back in eluriating as elutriation liquid. The purity of the washing process combined by above-mentioned elutriation and elution, the sodium chloride crystal not only made improves, and will not mistake More introducing cleaning solutions, 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 that remaining tail gas i.e. third heat-exchanger rig 33 is discharged；First heat exchange 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.

From the point of view of the energy consumption for reducing treatment process, the SO that contains in the catalyst production waste water₄ ^2-With Cl^-'s The higher the better for molar ratio, (the SO relative to 1mol₄ ^2-, Cl^-Preferably 10mol hereinafter, more preferably 8mol hereinafter, for example can be with For 1.3-6.5mol), from the point of view of improving sodium sulphate product purity, the Cl that contains in the catalyst production waste water^-For 5.23mol/L or less (preferably 5.09mol/L hereinafter, more preferably 4.5mol/L hereinafter, for example can be 1.8-3.9mol/ L).Pass through the SO that will contain in catalyst production waste water₄ ^2-And Cl^-Concentration be limited to above range, can be in crystallisation by cooling mistake The sodium sulphate of very high purity is obtained in journey, it is energy saving, keep treatment process more economical.

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 ammonia 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, such as 6.3-6.9.

In addition, due to catalyst production waste water COD concentration when may block up film, in evaporative crystallization when influence salt purity With color etc., the COD of the catalyst production waste water it is more fewer better (preferably 20mg/L hereinafter, more preferably 10mg/L with Under), preferably in pretreatment by oxidation removal, such as bioanalysis, advanced oxidation processes progress specifically can be used, in COD content Preferably use oxidizing when very high, 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 filtering, Subacidity cation exchange process, ozone biological activated carbon adsorption and oxidation Method cleans.By above-mentioned dedoping step, most suspended substances, hardness, silicon and organic matter can be removed, reduces device fouling Risk guarantees wastewater treatment process continuous and steady operation.

In the present invention, for the lower catalyst production waste water of salt content, processing method of the invention can utilized Before processing (preferably after above-mentioned removal of impurities), salt content is made to reach range required by waste water of the invention by being concentrated.It is excellent Selection of land, it is described concentration selected from ED film concentration and/or it is reverse osmosis；It is highly preferred that it is described be concentrated by ED film concentration and reverse osmosis penetrate into There is no particular limitation for the sequencing of row, the ED film concentration and reverse osmosis progress.The ED film concentration and reverse osmosis treatment Device and condition can carry out in such a way that this field is conventional, can be specifically chosen according to the case where waste water to be processed.Specifically Ground is concentrated as the ED film, and unidirectional electrodialysis system or pole-reversing electroosmosis system can be selected to carry out；As the reverse osmosis Thoroughly, rolled film, plate membrane, dish tubular membrane, vibrating membrane or combinations thereof can be selected to carry out.Waste water can be improved by the concentration The efficiency of processing avoids energy waste caused by largely evaporating.

In 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 again；If the ion concentration of catalyst production waste water is unsatisfactory for condition of the invention, can first carry out Second evaporation obtains the second concentrate and is separated by solid-liquid separation to obtain sodium chloride crystal and the second mother liquor, then by the second mother liquor with it is described Catalyst production waste water mixing come adjust waste water to be processed ion concentration be range of the presently claimed invention after cooled down again Crystallization obtains sodium sulfate crystal.Certainly sodium sulphate or sodium chloride also can be used to the ion in waste water to be processed in the initial stage Content is adjusted, as long as meeting the waste water to be processed in the present invention to SO in waste water to be processed₄ ^2-、Cl^-Requirement be It can.

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, by catalyst production waste water (48g/L containing NaCl, Na₂SO₄ 88.5g/L、NH₄Cl 23g/L、 (NH₄)₂SO₄43.1g/L, pH 6.9) it with inlet amount is 10m³The speed of/h is sent in the pipeline of processing system, Xiang Guandao It is middle to import the sodium hydrate aqueous solution progress first time pH value adjusting that concentration is 45.16 mass %, pass through the first pH value and measures dress It sets 61 (pH meters) and (measured value 7.6) is monitored to the pH value after adjusting, it is then by first circulation pump 71 that catalyst is raw The a part for producing waste water is sent into the first heat-exchanger rig 31 (two phase stainless steel plate heat exchanger) and is changed with the first liquid of steam condensation containing ammonia After heat, the second mother liquor returned with the 9th circulating pump 79 is mixed, and another part is sent into 30 (two phase stainless steel of the 11st heat-exchanger rig Plate heat exchanger) in the first concentrate exchange heat, merge above-mentioned two parts waste water to obtain waste water to be processed, by waste water to be processed Being sent into the 8th heat-exchanger rig 38 (two phase stainless steel plate heat exchanger) is warming up to waste water to be processed with the first steam heat-exchanging containing ammonia After 107 DEG C, then the sodium hydrate aqueous solution that concentration is 45.16 mass % is imported in the pipeline for being sent into MVR vaporising device 3 and is carried out Second pH value is adjusted, and is monitored that (measured value is to the pH value after adjusting by third pH value measuring device 60 (pH meter) 11)。

First evaporation carries out in MVR vaporising device 3, condition such as the following table 1, obtains the first steam containing ammonia and the first concentration Liquid.By the first steam containing ammonia after the compression of the first compressor 101 after (temperature rises 18 DEG C), successively in the 8th heat-exchanger rig 38 With carry out heat exchange with waste water to be processed and catalyst production waste water respectively in the first heat-exchanger rig 31, obtain the first ammonium hydroxide and store It is stored in the first tank used for storing ammonia 51.In addition, will be steamed in MVR vaporising device 3 to improve the strength of fluid in MVR vaporising device 3 Partially liq after hair is recycled to the 8th heat-exchanger rig 38 by the 5th circulating pump 75 as first circulation liquid, is then again introduced into MVR vaporising device 3 carries out the first evaporation (the first reflux ratio is 27.5).The flow of the 11st circulating pump 70 is controlled, and passes through MVR The densitometer being arranged on vaporising device 3 controls the degree of the first evaporation, and the concentration of the concentrate of the first evaporation of control is surveyed Contain NaCl 135.1g/L, Na in the first concentrate that must be obtained₂SO₄175.5g/L (i.e. Cl^-Concentration be 2.310mol/L, SO₄ ^2-Concentration be 1.237mol/L).

First concentrate is sent into the 11st heat-exchanger rig 30 with after catalyst production waste water heat exchange, is re-fed into the second heat exchange Device 32 (heat exchanger of plastic material) and the first mother liquor, which carry out the second heat exchange, makes the first concentrate be cooled to 19 DEG C, then with The cooling circulation liquid mixing of the equipment of crystallisation by cooling 2 of 72 conveying of second circulation pump, is changed in the 6th heat-exchanger rig 36 with freezing liquid After hot further cooling, it is sent into equipment of crystallisation by cooling 2 (freezing and crystallizing tank) and carries out crystallisation by cooling, obtain the knot of sulfur acid sodium crystal Brilliant liquid.Wherein, the temperature of crystallisation by cooling is -4 DEG C, time 125min, and the internal circulating load for controlling crystallisation by cooling is 1161m³/ h, control But the degree of supersaturation of sodium sulphate is not more than 1.1g/L to refrigeration in crystallization process.

The crystal solution for the sulfur acid sodium crystal that above-mentioned equipment of crystallisation by cooling 2 is obtained is sent into the first equipment for separating liquid from solid 91 After (centrifuge) is separated by solid-liquid separation, 3.79m is obtained per hour³Contain NaCl 284.9g/L, Na₂SO₄ 14.9g/L、 NaOH4.6g/L、NH₃The first mother liquor of 0.28g/L is temporarily stored into the first mother liquor tank 53, and obtaining purity per hour is 98.4 matter Measure the sal glauberi crystalli-zation cake 5468.15kg of %, aqueous 75 mass %.

Second evaporation process carries out in multi-effect evaporating device 1.By the first mother liquor be sent into the second heat-exchanger rig 32 with After the heat exchange of first concentrate, it is re-fed into the 4th heat-exchanger rig 34 (two phase stainless steel plate heat exchanger) and the second steam condensation containing ammonia Liquid carries out heat exchange, then (first exchanges heat in the 7th heat-exchanger rig 37 with heating vapour-condensing knot liquid before mixing) with the second cleaning solution It is sent into multi-effect evaporating device 1 after mixing, passes through the second pH value measuring device 62 in the pipeline for being sent to multi-effect evaporating device 1 (pH meter) is monitored (measured value 11) to pH value.The multi-effect evaporating device 1 is evaporated by 1st effective evaporator 1a, the second effect Device 1b, third effect evaporator 1c and fourth evaporator 1d composition (being forced-circulation evaporator).By first mother liquor according to Secondary be passed through is evaporated to obtain the second concentrate of sodium chloride-containing crystal in each effect evaporator of the multi-effect evaporating device 1.It will The second steam containing ammonia that preceding 1st effective evaporator obtains is passed through in rear 1st effective evaporator, and obtains the second ammonium hydroxide (the second steam containing ammonia Condensation water).Heating steam is passed through in 1st effective evaporator 1a, what heating steam obtained after condensing in 1st effective evaporator 1a Condensation water exchanges heat in the 7th heat-exchanger rig and the second cleaning solution.The second steam containing ammonia that fourth evaporator 1d is obtained is in third It exchanges heat in heat-exchanger rig 33 with cooling water (catalyst production waste water), obtains the second ammonium hydroxide.Above-mentioned second ammonium hydroxide is merged It is stored in the second tank used for storing ammonia 52.Second evaporation evaporation conditions such as the following table 1.Pass through the density being arranged on multi-effect evaporating device 1 It counts and the degree of the second evaporation is monitored, the concentration of sodium sulphate is 0.9605Y in the second concentrate after the second evaporation of control (48.6g/L)。

Table 1

The second concentrate of sulfur acid sodium and sodium chloride mixed crystal that second evaporation obtains in brilliant liquid collecting tank 55 into Row crystallization, temperature are -4 DEG C, and time 120min obtains the magma of sodium chloride-containing crystal.

The magma of sodium chloride-containing crystal is sent into the second equipment for separating liquid from solid 92 (centrifuge) and carries out the second separation of solid and liquid, often Hour obtains 1.63m³Contain NaCl 300.6g/L, Na₂SO₄ 48.6g/L、NaOH 0.37g/L、NH₃The of 0.0002g/L Two mother liquors are temporarily stored into the second mother liquor tank 54, and are returned to waste water conveyance conduit by the 9th circulating pump 79 and given up with catalyst production Water is mixed to get waste water to be processed.Gained solid sodium chloride (is obtained the sodium chloride that water content is 14 mass % to crystallize per hour Filter cake 829.28kg, wherein the content of sodium sulphate is 1.5 mass % or less) with the 300g/L's equal with sodium chloride butt quality It is dry in drying machine after sodium chloride solution elution, sodium chloride 713.18kg (purity is 99.5 mass %) is obtained per hour, is washed The second cleaning solution washed is recycled to multi-effect evaporating device 1 by the tenth circulating pump 80.

In the present embodiment, the ammonium hydroxide 3.16m that concentration is 4.9 mass % is obtained in the first tank used for storing ammonia 51 per hour³；The The ammonium hydroxide 2.76m that concentration is 0.03 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 90g/L containing NaCl, Na₂SO₄ 57.1g/L、NH₄Cl 23g/L、(NH₄)₂SO₄The catalyst production waste water that 14.8g/L, pH are 6.3 is handled, and is led to Crossing the 8th heat-exchanger rig 38 and carrying out the temperature of waste water to be processed after heat exchange is 114 DEG C.

Condition such as the following table 2 of first evaporation and the second evaporation；The temperature of crystallisation by cooling is -2 DEG C, time 120min；Knot Brilliant 75 DEG C of temperature, time 5min.NaCl 206.4g/L, Na in the first obtained concentrate₂SO₄102.8g/L (i.e. Cl^- Concentration be 3.528mol/L, SO₄ ^2-Concentration be 0.724mol/L).

Table 2

First equipment for separating liquid from solid 91 obtains the sal glauberi crystalli-zation cake 3063.23kg of aqueous 76 mass % per hour (purity is 98.6 mass %)；5.60m is obtained per hour³Concentration is NaCl 294.9g/L, Na₂SO₄ 16.4g/L、 NaOH3.8g/L、NH₃The first mother liquor of 0.11g/L.

Second equipment for separating liquid from solid 92 obtains the sodium chloride crystalli-zation cake that water content is 15 mass % per hour 1349.33kg finally obtains sodium chloride 1146.93kg per hour (purity is 99.5 mass %)；1.68m is obtained per hour³, dense Degree is NaCl297.8g/L, Na₂SO₄ 54.7g/L、NaOH 12.6g/L、NH₃The second mother liquor of 0.006g/L.

The ammonium hydroxide 3.68m that concentration is 2.65 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 0.015 mass % ammonium hydroxide 4.12m³。

Embodiment 3

According to the method for embodiment 1 carry out catalyst production waste water processing, unlike: to 60g/L containing NaCl, Na₂SO₄ 63g/L、NH₄Cl 34.1g/L、(NH₄)₂SO₄The catalyst production waste water that 36.4g/L, pH are 6.6 is handled, and is led to Crossing the 8th heat-exchanger rig 38 and carrying out the temperature of waste water to be processed after heat exchange is 112 DEG C.

Condition such as the following table 3 of first evaporation and the second evaporation；The temperature of crystallisation by cooling is 0 DEG C, time 120min；Crystallization Temperature 50 C, time 8min.NaCl 175g/L, Na in the first obtained concentrate₂SO₄139.3g/L (i.e. Cl^-It is dense Degree is 2.9907mol/L, SO₄ ^2-Concentration be 0.9806mol/L).

Table 3

First equipment for separating liquid from solid 91 obtains the sal glauberi crystalli-zation cake of aqueous 74.5 mass % per hour 4047.97kg (purity is 98.5 mass %)；4.89m is obtained per hour³Concentration is NaCl 286g/L, Na₂SO₄ 18.9g/L、 NaOH18.9g/L、NH₃The first mother liquor of 0.24g/L.

Second equipment for separating liquid from solid 92 obtains the sodium chloride crystalli-zation cake that water content is 14 mass % per hour 1118.83kg finally obtains sodium chloride 962.19kg per hour (purity is 99.5 mass %)；1.49m is obtained per hour³Concentration For NaCl286.5g/L, Na₂SO₄ 62.1g/L、NaOH 4.2g/L、NH₃The second mother liquor of 0.016g/L.

The ammonium hydroxide 3.49m that concentration is 4.9 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 0.03 mass % ammonium hydroxide 3.58m³。

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 steam containing ammonia and the first concentrate, the waste water to be processed contains There is the catalyst production waste water；

3) crystal solution 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 phase for first and leads to Each effect evaporator for entering multi-effect evaporating device carries out the second evaporation, and obtain the second steam containing ammonia and sodium chloride-containing crystal second is dense Contracting 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；

SO in first concentrate₄ ^2-Concentration be 0.01mol/L or more；

Second evaporation is precipitated sulfate crystal.

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 second separation of solid and liquid obtains Liquid；

Preferably, the SO contained in first concentrate₄ ^2-Concentration be 0.1mol/L or more, more preferably 0.2mol/L with On；

Preferably, the Cl contained in first concentrate^-Concentration be 5mol/L hereinafter, more preferably 4.5mol/L or less；

Preferably, the SO contained in obtained liquid phase is separated by solid-liquid separation relative to described in 1mol first₄ ^2-, described first is separated by solid-liquid separation The Cl contained in obtained liquid phase^-For 9.5mol 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. method according to claim 1 or 2, wherein before the crystallisation by cooling, SO in first concentrate₄ ^2- Concentration be 0.01mol/L or more, Cl^-Concentration be 5.2mol/L or less；

Preferably, the crystallisation by cooling is precipitated sodium chloride crystallization；

Preferably, before the crystallisation by cooling, the concentration of sodium chloride in first concentrate is adjusted；

Preferably, the concentration for adjusting sodium chloride in first concentrate is separated by solid-liquid separation obtained liquid phase, institute by mixing second It states catalyst production waste water and/or elutes the cleaning solution progress of sodium sulfate crystal.

4. method described in any one of -3 according to claim 1, wherein second evaporation makes in second concentrate The concentration of sodium sulphate is Y or less, wherein Y is sodium sulphate and sodium chloride in second concentrate under conditions of the second evaporation The concentration of sodium sulphate when reaching saturation；

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

5. 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 using MVR vaporising device.

6. 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.

7. method described in any one of -4 according to claim 1, wherein the condition of second evaporation includes: that temperature is 17.5 DEG C or more, pressure is -101kPa or more；

Preferably, it is 35 DEG C~110 DEG C that the condition of the evaporation, which includes: temperature, and pressure is -98kPa~12kPa；

Preferably, it is 45 DEG C~110 DEG C that the condition of the evaporation, which includes: temperature, and pressure is -95kPa~12kPa；

Preferably, it is 50 DEG C~100 DEG C that the condition of the evaporation, which includes: temperature, and pressure is -93kPa~-22kPa；

Preferably, in the second evaporation, 5 DEG C of evaporating temperature difference of adjacent two-effect evaporation device or more is preferably 5 DEG C~30 DEG C, more excellent Select 10 DEG C~20 DEG C.

8., will be described before the waste water to be processed is carried out the first evaporation according to the method described in claim 1, wherein Waste water to be processed and first steam containing ammonia carry out the first heat exchange, and obtain the first ammonium hydroxide；

Preferably, before first concentrate is carried out crystallisation by cooling, by first concentrate and first solid-liquid Isolated liquid phase carries out the second heat exchange；

Preferably, before the liquid phase for obtaining first separation of solid and liquid is passed through multi-effect evaporating device, contain ammonia for described second Steam and described first is separated by solid-liquid separation obtained liquid phase progress third heat exchange and obtains ammonium hydroxide.

9. method described in any one of -8 according to claim 1, this method further includes by the knot of the sulfur acid sodium crystal Brilliant liquid obtains sodium sulfate crystal after first is separated by solid-liquid separation；

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

10. method described in any one of -8 according to claim 1, this method further includes by the of the sodium chloride-containing crystal Two concentrates obtain sodium chloride crystal after second is separated by solid-liquid separation；

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

11. method described in any one of -8 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.