CN108726762A

CN108726762A - A kind of processing method of catalyst production waste water

Info

Publication number: CN108726762A
Application number: CN201710265378.8A
Authority: CN
Inventors: 殷喜平; 李叶; 苑志伟; 吕伟娇; 周岩; 杨凌; 顾松园; 王涛; 刘志坚; 刘夫足; 高晋爱; 安涛
Original assignee: China Petroleum and Chemical Corp; Sinopec Catalyst Co
Current assignee: China Petroleum and Chemical Corp; Sinopec Catalyst Co
Priority date: 2017-04-21
Filing date: 2017-04-21
Publication date: 2018-11-02
Anticipated expiration: 2037-04-21
Also published as: CN108726762B

Abstract

The present invention relates to sewage treatment fields, disclose the processing method of catalyst production waste water, which contains NH₄ ⁺、SO₄ ^2‑、Cl^‑And Na⁺, this method includes 1) by pending waste water be passed through the first MVR vaporising devices carry out first evaporation obtain the first concentrate of the first steam containing ammonia and sulfur acid sodium crystal and sodium chloride crystal, the pending waste water contains catalyst production waste water；2) first concentrate is subjected to low-temperature treatment, so that sodium sulfate crystal is dissolved, obtains the treatment fluid of sodium chloride-containing crystal；3) treatment fluid of the sodium chloride-containing crystal is carried out first to be separated by solid-liquid separation, and the liquid phase that the first separation of solid and liquid obtains is passed through the second evaporation of progress in the 2nd MVR vaporising devices and obtains the second concentrate of the second steam containing ammonia and sulfur acid sodium crystal；4) the second concentrate of the sulfur acid sodium crystal second is carried out to be separated by solid-liquid separation.Ammonium and sodium sulphate, sodium chloride in waste water can be separately recovered in this method, farthest recycle the resource in waste water.

Description

A kind of 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 technology

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

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

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

Invention content

The purpose of the present invention is overcome to contain NH in the prior art₄ ⁺、SO₄ ^2-、Cl^-And Na⁺Catalyst production waste water be processed into This height, and the problem of can only obtain mixing salt crystal provides and a kind of at low cost and environmentally friendly contains NH₄ ⁺、SO₄ ^2-、Cl^-And Na⁺ Wastewater treatment method, ammonium and sodium chloride, sodium sulphate in waste water can be separately recovered in this method, farthest recycle useless Resource in 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) pending waste water is passed through the first evaporation of the first MVR vaporising devices progress and obtains the first steam containing ammonia and sulfur acid First concentrate of sodium crystal and sodium chloride crystal, the pending waste water contain the catalyst production waste water；

2) the first concentrate of the sulfur acid sodium crystal and sodium chloride crystal is subjected to low-temperature treatment, makes sodium sulfate crystal Dissolving, obtains the treatment fluid of sodium chloride-containing crystal；

3) treatment fluid of the sodium chloride-containing crystal is carried out first to be separated by solid-liquid separation, and obtained liquid is separated by solid-liquid separation by first It is mutually passed through the second evaporation of progress in the 2nd MVR vaporising devices and obtains the second concentration of the second steam containing ammonia and sulfur acid sodium crystal Liquid；

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

Wherein, before the pending waste water is passed through the first MVR vaporising devices, the pH of the pending waste water is adjusted Value is more than 9；Second evaporation makes sodium chloride crystal not crystallize precipitation；Relative to what is contained in 1 mole of pending waste water SO₄ ^2-, the Cl that contains in the pending waste water^-It is 7.15 moles or more.

Through the above technical solutions, for NH is contained₄ ⁺、SO₄ ^2-、Cl^-And Na⁺Waste water, by advance by pending waste water After pH value is adjusted to specific range, the first MVR vaporising devices is recycled to be evaporated isolated sulfur acid sodium crystal and chlorine Change the concentrate of sodium crystal and compared with concentrated ammonia liquor, low-temperature treatment then recycled to make the dissolving of sodium sulphate in concentrate, sodium chloride into One-step crystallization is precipitated, and obtains sodium chloride crystal, then the 2nd MVR vaporising devices is recycled to be evaporated to obtain sulfur acid sodium again The concentrate of crystal and compared with weak aqua ammonia, obtains sulfate crystal.This method can respectively obtain the sodium chloride and sulfuric acid of high-purity Sodium, the difficulty during avoiding mixed salt processing and recycling, is completed at the same time separation of ammonia and the process of salt, and use heat exchange Waste water is made to heat up simultaneously for mode and steam containing ammonia condenses, the reasonable heat using in evaporation process, energy saving, reduces at waste water Cost is managed, the ammonium in waste water is recycled in the form of ammonium hydroxide, and sodium sulphate and sodium chloride are recycled with crystal form respectively, and whole process does not have There is waste residue and liquid generation, realizes the purpose to turn waste into wealth.

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

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

Description of the drawings

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

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

Reference sign

1, the 2nd MVR vaporising devices 72, second circulation pump

2, the first MVR vaporising devices 73, third circulating pump

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

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

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

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

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

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

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

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

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

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

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

71, first circulation pumps the 102, second compressor

Specific implementation mode

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

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

Below in conjunction with Fig. 1, 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 pending waste water is the catalyst production waste water；Alternatively, the pending waste water 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 pending waste water is the catalyst production waste water is separated by solid-liquid separation obtained liquid with described second At least part of mixed liquor of phase.

It is obtained with second separation of solid and liquid it is further preferred that the pending waste water is the catalyst production waste water Liquid phase mixed liquor.

Preferably, before the pending waste water is passed through the first MVR vaporising devices 2, the pending waste water is adjusted PH value be more than 10.8.In addition, for the pending waste water pH value the upper limit there is no limit, such as can be 14 hereinafter, Preferably 13.5 hereinafter, more preferable 13 or less.

Method provided by the invention, which can be directed to, contains NH₄ ⁺、SO₄ ^2-、Cl^-And Na⁺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.From raising waste water Treatment effeciency from the point of view of, relative to the SO contained in 1 mole of pending waste water₄ ^2-, contain in the pending waste water Some Cl^-It is 7.15 moles or more, preferably 9.5 moles or more, preferably 10 moles or more, preferably 50 moles hereinafter, more Preferably 40 moles hereinafter, further preferably 30 moles hereinafter, for example can be 8-20 moles, preferably 8-12 moles, more Preferably 10-12 moles.By by SO₄ ^2-And Cl^-Molar ratio control in above range, sodium chloride in low-temperature treatment can be made Be precipitated and sodium sulphate is completely dissolved, to achieve the purpose that efficiently separate sodium chloride.In addition, it is as above described below, in the present invention In and can also thus come in pending waste water by the second Recycling Mother Solution obtained in the second evaporation process to the first evaporation SO₄ ^2-And Cl^-Molar ratio be adjusted, and the balance of sodium hydroxide can be maintained.

In the present invention, first evaporation needs that sodium sulfate crystal is made to dissolve in low-temperature treatment, specifically, the The first concentrate of sulfur acid sodium crystal and sodium chloride crystal is obtained in one evaporation, need to ensure that sodium sulfate crystal therein can be It is completely dissolved in low-temperature treatment.By controlling the evaporation capacity of first evaporation, makes sodium sulphate, sodium chloride while crystallizing precipitation (the i.e. first evaporation obtains the first concentrate of sulfur acid sodium crystal and sodium chloride crystal), then sulfur-bearing is made by the low-temperature treatment Sodium sulfate crystal dissolving in first concentrate of sour sodium crystal and sodium chloride crystal, sodium chloride further crystallize precipitation, obtain Contain only the treatment fluid of sodium chloride crystal.Treatment fluid about the sodium chloride-containing crystal, it is not excluded that sodium chloride crystallization entrainment or The sodium sulphate of adsorption.Since the water content of crystal after separation of solid and liquid is different, sodium sulphate in the sodium chloride crystal generally yielded Content below 8 mass % (preferably 4 mass %), in the present invention, the content of sodium sulphate in obtained sodium chloride crystal It can think that sodium sulphate has dissolved when below 8 mass %.

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

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

In the present invention, there is no particular limitation for the first MVR vaporising devices 2, can be commonly used in the art Various MVR vaporising devices.Such as can be selected from MVR falling film evaporators, MVR forced-circulation evaporators, MVR-FC continuous crystallisations It is one or more in evaporator, MVR-OSLO continuous crystallisation evaporators.Wherein, preferably MVR forced-circulation evaporators, MVR- FC continuous crystallisation evaporators, more preferably falling liquid film+forced circulation two-stage MVR crystallizing evaporators.

In the present invention, the condition of first evaporation can be selected suitably as needed, and described the can be controlled by reaching One evaporation evaporation capacity, make sodium sulphate, sodium chloride simultaneously crystallize precipitation (i.e. first evaporate obtain sulfur acid sodium crystal and sodium chloride First concentrate of crystal), then made in the first concentrate of sulfur acid sodium crystal and sodium chloride crystal by the low-temperature treatment Sodium sulfate crystal dissolving, sodium chloride further crystallizes precipitation, obtains the purpose for the treatment fluid for containing only sodium chloride crystal.Institute The condition for stating the first evaporation may include：Temperature is 35 DEG C or more, and pressure is -95kPa or more.It is excellent in order to improve evaporation efficiency Selection of land, it is described first evaporation condition include：Temperature is 45 DEG C~175 DEG C, and pressure is -95kPa~18110kPa；Preferably, It is described first evaporation condition include：Temperature is 60 DEG C~175 DEG C, and pressure is -87kPa~18110kPa；Preferably, described One evaporation condition include：Temperature is 75 DEG C~175 DEG C, and pressure is -73kPa~653kPa；Preferably, it is described first evaporation Condition includes：Temperature is 80 DEG C~130 DEG C, and pressure is -66kPa~117kPa；Preferably, the condition packet of first evaporation It includes：Temperature is 95 DEG C~110 DEG C, and pressure is -37kPa~12kPa；Preferably, the condition of first evaporation includes：Temperature is 100 DEG C~110 DEG C, pressure is -23kPa~12kPa.

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

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

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

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

According to the present invention, first evaporation makes sodium sulfate crystal be dissolved in low-temperature treatment, it is preferable that described first steams Hair makes a concentration of Y or less (preferably 0.9Y-0.99Y, preferably 0.95Y-0.98Y) of sodium sulphate in the treatment fluid, wherein Y is the concentration of sodium sulphate when sodium chloride and sodium sulphate reach saturation in treatment fluid under conditions of low-temperature treatment.Pass through Within the above range by the extent control of the first evaporation, can make under conditions of ensureing that low-temperature treatment can be such that sodium sulphate dissolves Sodium chloride crystallization as much as possible is precipitated.By making sodium chloride crystallize in the first evaporation as possible, wastewater treatment effect can be improved Rate reduces energy waste.

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

The pending waste water is being passed through the first MVR vaporising devices 2 by a preferred embodiment according to the present invention Before, first steam containing ammonia is subjected to the first heat exchange with the pending waste water and obtains the first ammonium hydroxide.Described first There is no particular limitation for the mode of heat exchange, and the heat exchange mode that this field routine may be used carries out.First heat exchange Number can be preferably 2-4 times, more preferably 2-3 times more than primary.After first heat exchange, the ammonium hydroxide of output Cooled, heat utmostly recycles inside processing unit, and the energy is rationally utilized, and reduces waste.

A preferred embodiment according to the present invention, first heat exchange pass through the first heat-exchanger rig the 31, the 5th Heat-exchanger rig 35 and the second heat-exchanger rig 32 carry out, specifically, the will evaporated in the first MVR vaporising devices 2 One steam containing ammonia passes sequentially through the second heat-exchanger rig 32 and the first heat-exchanger rig 31, by sulfur acid sodium crystal and sodium chloride crystal The pending waste water is first passed through the first heat-exchanger rig 31 or the 5th and is changed by the first concentrate by the 5th heat-exchanger rig 35 After thermal 35 carries out the first heat exchange, then pass through the first heat exchange of progress of the second heat-exchanger rig 32.It is handed over by first heat It changes, makes the pending waste water heating be convenient for evaporating, while first steam containing ammonia being made to condense to obtain the first ammonium hydroxide, institute Stating the first ammonium hydroxide can be stored in the first tank used for storing ammonia 51.

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

It is preferably exchanged heat by described first according to the present invention in order to make full use of the thermal energy of the first liquid of steam condensation containing ammonia After device 31 carries out the first heat exchange, the temperature of the pending waste water is 44 DEG C~174 DEG C, more preferably 59 DEG C~174 DEG C, Further preferably 79 DEG C~129 DEG C, be still more preferably 94 DEG C~109 DEG C.

According to the present invention, in order to make full use of the thermal energy of the first concentrate, preferably the is carried out by the 5th heat-exchanger rig 35 After one heat exchange, the temperature of the pending waste water is 44 DEG C~174 DEG C, more preferably 59 DEG C~174 DEG C, further preferably 79 DEG C~129 DEG C, be still more preferably 94 DEG C~109 DEG C.

Preferably pass through second heat-exchanger rig 32 according to the present invention in order to make full use of the thermal energy of the first steam containing ammonia After carrying out the first heat exchange, the temperature of the pending waste water is 52 DEG C~182 DEG C, more preferably 67 DEG C~182 DEG C, further Preferably 87 DEG C~137 DEG C, be still more preferably 102 DEG C~117 DEG C.

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

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

A preferred embodiment according to the present invention, first evaporation process in the first MVR vaporising devices 2 into Row leads to before the pending waste water to be sent into the first heat-exchanger rig 31 or the first heat exchange of progress of the 5th heat-exchanger rig 35 It crosses and the pending waste water is being sent into the aqueous solution containing alkaline matter of importing in the pipeline of heat-exchanger rig and mixing, come Carry out first time pH value adjusting；Then the pending waste water is sent into the first heat-exchanger rig 31 or the 5th heat-exchanger rig 35 carries out Next first heat exchange is sent into the pipeline of the second heat-exchanger rig 32 described in importing by the pending waste water containing alkalinity The aqueous solution of substance and mixing, to carry out second of pH value adjusting.It is adjusted by pH value twice, makes the pending waste water logical PH value before entering the first MVR vaporising devices 2 is more than 9, preferably greater than 10.8.Preferably, first time pH value adjusting makes The pH value for obtaining pending waste water is more than 7 (preferably 7-9), and second of pH value adjusts so that pH value (is preferably greater than more than 9 10.8).In accordance with the present invention it is preferred that before carrying out first heat exchange, the pH value for adjusting the pending waste water is more than 7。

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

In the present invention, the first heat exchange, adjust the pH value of the pending waste water and the tune of the pending waste water With process, (the pending waste water contains the case where catalyst production waste water is separated by solid-liquid separation obtained liquid phase with described second Under, need the allocation process for carrying out the pending waste water) carry out priority there is no particular limitation, can be fitted as needed When selection, before the pending waste water is passed through the first MVR vaporising devices complete.

In the present invention, in order to improve the solid content in the first MVR vaporising devices 2, the ammonia reduced in liquid contains Amount, preferably by the partially liq after the first MVR vaporising devices 2 evaporation (namely inside the first MVR vaporising devices Liquid, also referred to as first circulation liquid hereinafter) again return in the first MVR vaporising devices 2 after heating and evaporate.It is above-mentioned by institute The process for stating first circulation liquid back to the first MVR vaporising devices 2 is preferably, by the first circulation liquid and for the first time The first MVR vaporising devices are again returned to after pH value is adjusted and after the pending waste water mixing before being adjusted to second of pH value In 2, the first circulation liquid is filled back to the heat exchange of the first heat-exchanger rig 31 and second for example, 72 can be pumped by second circulation It sets in the waste water conveyance conduit between 32 and is mixed with pending waste water, after then being adjusted using second of pH value, Second heat-exchanger rig 32 carries out heat exchange, is finally sent into the first MVR vaporising devices 2.As the first MVR will be passed through The ratio that partially liq after the evaporation of vaporising device 2 flows back into the first MVR vaporising devices 2 is not particularly limited, for example, First reflux ratio of first evaporation can be appropriately configured as needed, can be 10-200, preferably 40-150.? This, first reflux ratio refers to：Regurgitant volume subtracts the ratio of regurgitant volume with the total amount of liquid being sent into the first MVR vaporising devices 2 Value.

In the case of, according to the invention it is preferred to, the method further include 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 systems, ensures that the process of waste water heating-evaporation-cooling is continuous It carries out, needs to input when MVR evaporation processes start and start steam, reach after continuously running state only by the first compressor 101 Energy supply, it is no longer necessary to input other energy.Various compressions commonly used in the art may be used in first compressor 101 Machine, such as centrifugal blower, turbocompressor or lobed rotor compressor etc..After first compressor 101 compression, described first The temperature of the steam containing ammonia increases 5 DEG C~20 DEG C.

In the present invention, the first concentrate of the sulfur acid sodium crystal and sodium chloride crystal is subjected to low-temperature treatment, made Sodium sulfate crystal dissolves, and obtains the treatment fluid of sodium chloride-containing crystal.By controlling the evaporation capacity of first evaporation, make the place A concentration of Y of sodium sulphate in liquid is managed hereinafter, can make in low-temperature process, sodium sulfate crystal can be completely dissolved.

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

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

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

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

According to the present invention, the separation of solid and liquid of first concentrate may be used the first equipment for separating liquid from solid (be, for example, from Scheming, band filter, flame filter press etc.) 91 progress.After the separation of solid and liquid, the first equipment for separating liquid from solid 91 obtain One mother liquor is temporarily stored into the first mother liquor tank 53, and can be sent into the 2nd MVR vaporising devices 1 by the 6th circulating pump 76 and be carried out second Evaporation.In addition, being difficult to avoid that adsorb certain chlorion, free ammonia, hydroxide ion etc. miscellaneous on obtained sodium chloride crystal Matter reduces the peculiar smell of solid salt to remove the impurity of absorption, reduces corrosivity, improves the purity of the crystal, it is preferable that Sodium chloride crystal water, the catalyst production waste water or sodium chloride solution carry out the first washing and drying.In order to avoid The dissolving of sodium chloride crystal in washing process, it is preferable that the sodium chloride crystal is washed with sodium-chloride water solution.More preferably Ground, the concentration of the sodium-chloride water solution are preferably that sodium chloride and sodium sulphate is simultaneously at the temperature corresponding to sodium chloride crystal to be washed Reach the concentration of sodium chloride in the aqueous solution of saturation.

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

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

In the present invention, there is no particular limitation for the 2nd MVR vaporising devices 1, can be commonly used in the art Various MVR vaporising devices.Such as can be selected from MVR falling film evaporators, MVR forced-circulation evaporators, MVR-FC continuous crystallisations It is one or more in evaporator, MVR-OSLO continuous crystallisation evaporators.Wherein, preferably MVR forced-circulation evaporators, MVR- FC continuous crystallisation evaporators, more preferably falling liquid film+forced circulation two-stage MVR crystallizing evaporators.

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

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

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

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

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

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

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

In the case of, according to the invention it is preferred to, second heat exchange is exchanged heat by third heat-exchanger rig 33 and the 4th and is filled 34 progress are set, specifically, the second steam containing ammonia evaporated in the 2nd MVR vaporising devices 1 are passed sequentially through the 4th Heat-exchanger rig 34 and third heat-exchanger rig 33, and by first mother liquor by third heat-exchanger rig 33, then with second circulation Liquid (the partial concentration liquid in the 2nd MVR vaporising devices 1) mixes, and obtained mixed liquor is passed through the 4th heat-exchanger rig 34, the second heat exchange is carried out, makes the first mother liquor heating be convenient for evaporating, while second steam containing ammonia being made to condense To the second ammonium hydroxide, second ammonium hydroxide can be stored in the second tank used for storing ammonia 52.

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

In the present invention, it in order to improve the solid content of concentrate in the 2nd MVR vaporising devices 1, reduces in liquid Ammonia content, preferably by by the 2nd MVR vaporising devices 1 evaporation after partially liq (namely positioned at the 2nd MVR evaporation dress The liquid inside 1 is set, hereinafter also referred to as second circulation liquid) back in the 2nd MVR vaporising devices 1.It is above-mentioned by described The process of two circulation fluids back to the 2nd MVR vaporising devices 1 is preferably, by second circulation liquid and the second leacheate, first Mother liquor mixes, and returns again to the 2nd MVR vaporising devices 1.For example, can be by the 7th circulating pump 77 by the second circulation liquid and Two leacheates, are passed through the 4th heat-exchanger rig 34 again after being mixed in the duct with the first mother liquor, after carrying out the second heat exchange, return to the Two MVR vaporising devices 1.Partially liq after the 2nd MVR vaporising devices 1 evaporation is flowed back into the 2nd MVR to steam There is no particular limitation for the ratio of transmitting apparatus 1, for example, the second reflux ratio of second evaporation can be 0.1-100, preferably 5-50.Here, second reflux ratio refers to：Regurgitant volume subtracts reflux with the total amount of liquid being sent into the 2nd MVR vaporising devices 1 The ratio of amount.

In the case of, according to the invention it is preferred to, the method further include after second steam containing ammonia is compressed again Carry out second heat exchange.The compression of second steam containing ammonia can be carried out by the second compressor 102.By to described Second steam containing ammonia is compressed, and to input energy in MVR vapo(u)rization systems, ensures that the process of waste water heating-evaporation-cooling is continuous It carries out, needs to input when MVR evaporation processes start and start steam, reach after continuously running state only by the second compressor 102 Energy supply, it is no longer necessary to input other energy.Various compressions commonly used in the art may be used in second compressor 102 Machine, such as centrifugal blower, turbocompressor or lobed rotor compressor etc..After second compressor 102 compression, described second The temperature of the steam containing ammonia increases 5 DEG C~20 DEG C.

A preferred embodiment according to the present invention, second evaporation process in the 2nd MVR vaporising devices 1 into First mother liquor is passed through in the 2nd MVR vaporising devices 1 by the 6th circulating pump 76 and carries out the second evaporation and obtain the by row Second concentrate of two steam containing ammonia and sulfur acid sodium crystal.

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

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

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

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

A preferred embodiment according to the present invention obtains the second of sulfur acid sodium crystal dense by the second evaporation Contracting liquid carries out first time elutriation with the catalyst production waste water after settling progress tentatively separation of solid and liquid in eluriating tank, Then it reuses the liquid obtained when subsequent wash sodium sulfate crystal and carries out second of elutriation in another elutriation tank, finally will Slurries after eluriating twice are sent into the second equipment for separating liquid from solid and are separated by solid-liquid separation, and the crystal being separated by solid-liquid separation uses sulphur again Acid sodium aqueous solution is eluted, and the liquid that elution is obtained is used as back in eluriating for the second time and eluriates liquid.It is washed in a pan by above-mentioned Wash and elute the washing process combined, the purity of the sodium sulfate crystal not only made improves, and will not excessive introducing wash Liquid is washed, the efficiency of wastewater treatment is improved.

A preferred embodiment according to the present invention, first steam containing ammonia is cold by first heat exchange Remaining tail gas is coagulated to discharge after removing ammonia；Second steam containing ammonia is condensed remaining tail gas by second heat exchange to pass through Except being discharged after ammonia.First steam containing ammonia condenses remaining tail gas, that is, second heat-exchanger rig by first heat exchange The tail gas of 32 discharges, second steam containing ammonia condense remaining i.e. the 4th heat-exchanger rig 34 of tail gas by second heat exchange The tail gas of discharge.By the way that above-mentioned tail gas is removed ammonia, the pollutant load in emission can be further decreased so that it can straight Run in and puts.

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

In the present invention, there is no particular limitation for the catalyst production waste water, as long as containing NH₄ ⁺、SO₄ ^2-、Cl^-And Na⁺ Waste water.In addition, the method for the present invention is particularly suitable for the processing of high-salt wastewater.Dead catalyst as the present invention produces Water is specifically as follows the waste water from molecular sieve, aluminium oxide or oil refining catalyst production process, and can also be will be from molecule 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 ⁺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^-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 100g/L hereinafter, preferably 50g/L or less.

It is useless relative to catalyst production from the point of view of the energy consumption for reducing processing procedure from the efficiency for improving the first evaporation The SO contained in water₄ ^2-, the Cl in catalyst production waste water^-The higher the better for content, for example, useless relative to 1 mole of ammonium salt-containing The SO contained in water₄ ^2-, the Cl that contains in the catalyst production waste water^-It is 1 mole or more, preferably 2 moles or more, preferably It is 5 moles or more, more preferably 9.5 moles or more, further preferably 10 moles or more.And from the point of view of practicability, Relative to the SO contained in 1 mole of catalyst production waste water₄ ^2-, the Cl that contains in the catalyst production waste water^-Preferably 200 moles hereinafter, more preferably 150 moles hereinafter, further preferably 100 moles hereinafter, still more preferably be 50 moles Hereinafter, being still more preferably 30 moles or less.Pass through the Cl that will contain in catalyst production waste water^-And SO₄ ^2-Molar ratio limit It is scheduled on above range, most of water can be steamed in the first evaporation, be reduced the circulation fluid scale of construction in system for handling, save energy Source keeps processing procedure 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 10mg/L is not hereinafter, contain other inorganic ions particularly preferably.It, can by controlling other inorganic ions in above range To further increase the purity of finally obtained sodium chloride crystal and sodium sulfate crystal.In order to reduce the catalyst production waste water In other inorganic ions content, preferably carry 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 6.5-7.5.

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

In the present invention, in order to reduce the concentration impurity ion in catalyst production waste water, ensure the continuous of processing procedure Stablize and carry out, reduces equipment operation maintenance cost, the catalyst production waste water is before using the processing of the processing method of the present invention Preferably through removal of impurities.Preferably, the one kind of the removal of impurities in separation of solid and liquid, chemical precipitation, absorption, ion exchange and oxidation Or it is a variety of.

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

Specific removal of impurities mode can be specifically chosen according to the dopant species contained in the catalyst production waste water.For Suspended matter can select solid-liquid isolation method to clean；For inorganic matter and organic matter, chemical precipitation method, ion exchange can be selected Method, absorption method removal of impurities, such as Subacidity cation exchange process, active carbon adsorption etc.；For organic matter, absorption may be used 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 is successively by 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 ensures wastewater treatment process continuous and steady operation.

It in the present invention, can be in the processing method using the present invention for the lower catalyst production waste water of salt content Before processing (preferably after above-mentioned removal of impurities), made required by the catalyst production waste water that salt content reaches the present invention by concentrating Range.Preferably, it is described concentration selected from ED films concentration and/or it is reverse osmosis；It is highly preferred that it is described be concentrated by ED films concentration and There is no particular limitation for the sequencing of reverse osmosis progress, the ED films concentration and reverse osmosis progress.ED films concentration and anti- The mode that this field routine may be used in infiltration processing unit and condition carries out, and can specifically be selected according to the case where pending waste water It selects.Specifically, it is concentrated as the ED films, unidirectional electrodialysis system or pole-reversing electroosmosis system can be selected to carry out；As institute State it is reverse osmosis, can select rolled film, plate membrane, dish tubular membrane, vibrating membrane or combinations thereof carry out.It can be carried by the concentration The efficiency of high wastewater treatment avoids energy waste caused by largely evaporating.

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

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

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

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

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

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

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

It according to the present invention, when proceeding by wastewater treatment, can directly be gone into operation using catalyst production waste water, if catalysis The ion concentration of agent production waste water meets the condition of the present invention, can first carry out the first evaporation, low temperature with condition according to the invention Processing carries out the second evaporation again；If the ion concentration of catalyst production waste water is unsatisfactory for the condition of the present invention, the can be controlled One evaporation makes the concentration of sodium sulphate in the first concentrate close to concentration is precipitated, and the first concentrate is then carried out low-temperature treatment and the Two evaporations obtain the second concentrate and are separated by solid-liquid separation to obtain sodium sulfate crystal and the second mother liquor, then the second mother liquor is urged with described Change agent production waste water mixing come adjust pending waste water ion concentration be range of the presently claimed invention after carry out the first steaming again Hair obtains sodium chloride crystal.Certainly Na can also be used in the starting stage₂SO₄Or NaCl is to the ion concentration in pending waste water It is adjusted, as long as the pending waste water is made to meet in the present invention to SO in pending waste water₄ ^2-、Cl^-Requirement.

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

In following embodiment, 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 pass through ED films successively and concentrate Waste water after being concentrated with reverse osmosis.

Embodiment 1

As shown in Figure 1, by catalyst production waste water (159g/L containing NaCl, Na₂SO₄ 48g/L、NH₄Cl 39g/L、 (NH₄)₂SO₄12g/L, pH 7) with inlet amount it is 5m³The speed of/h is sent into processing system by first circulation pump 71, is being sent into To importing a concentration of 45.16 matter in the main pipeline of the first heat-exchanger rig 31 and the 5th heat-exchanger rig 35 (titanium alloy plate heat exchanger) Measure % sodium hydrate aqueous solution carry out first time pH value adjusting, and by the first pH value measuring device 61 (pH meter) to adjusting after PH value be monitored (measured value 7.8), by by the first pH value adjusting after catalyst production waste water be respectively fed to first Heat-exchanger rig 31 and the 5th heat-exchanger rig 35, the sulfur acid sodium obtained respectively with the first liquid of steam condensation containing ammonia and the first evaporation are brilliant First concentrate of body and sodium chloride crystal, which carries out the first heat exchange, makes catalyst production waste water be warming up to 102 DEG C；Then with Two mother liquors are mixed to get the pending waste water (SO wherein contained₄ ^2-And Cl^-Molar ratio be 1：11.346), then will be pending The sodium hydrate aqueous solution that a concentration of 45.16 mass % is imported in the pipeline of waste water the second heat-exchanger rig 32 of feeding carries out second PH value is adjusted, and is monitored (measured value 11) to the pH value after adjusting by the second pH value measuring device 62 (pH meter), so Being sent into the first steam containing ammonia the first heat exchange of progress of the second heat-exchanger rig 32 (titanium alloy plate heat exchanger) and recycling afterwards makes to wait for Processing waste water is warming up to 112 DEG C, then by the pending waste water after the first heat exchange twice with 476.5m³/ h is sent into first MVR vaporising devices 2 (falling liquid film+forced circulation two-stage MVR crystallizing evaporators) are evaporated, and obtain the first steam containing ammonia and sulfur acid First concentrate of sodium crystal and sodium chloride crystal.Wherein, the evaporation conditions of the first MVR vaporising devices 2 include：Temperature is 105 DEG C, pressure is -7.02kPa, evaporation capacity 4.82m³/h.The first obtained steam containing ammonia is evaporated to press by the first compressor 101 (18 DEG C of temperature rise) passes sequentially through the second heat-exchanger rig 32 and the first heat-exchanger rig 31 after contracting, and hot friendship is carried out with pending waste water It changes, cooling obtains the first ammonium hydroxide, and is stored in the first tank used for storing ammonia 51.In addition, in order to improve in the first MVR vaporising devices 2 Partially liq after being evaporated in first MVR vaporising devices 2 is recycled to the by the solid content of concentrate by second circulation pump 72 Then two heat-exchanger rigs 32 are again introduced into the first MVR vaporising devices 2 and carry out the first evaporation (reflux ratio 95.3).Pass through first The degree that the mass flowmenter pair first being arranged on MVR vaporising devices 2 evaporates is monitored, and the evaporation capacity of the first evaporation of control is 4.82m³/ h (a concentration of 0.978Y (88.9g/L) for being equivalent to sodium sulphate in control process liquid).

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

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

Second evaporation process is in the 2nd MVR vaporising devices 1 (falling liquid film+forced circulation two-stage MVR crystallizing evaporators) It carries out.The first mother liquor in above-mentioned first mother liquor tank 53 is sequentially sent to third heat-exchanger rig 33 and by the 6th circulating pump 76 After four heat-exchanger rigs 34, it is sent into the second evaporation of the 2nd MVR vaporising devices 1 progress and obtains the second concentrate of sulfur acid sodium crystal. Wherein, the evaporation conditions of the 2nd MVR vaporising devices 1 include：Temperature is 105 DEG C, and pressure is -7.02kPa, and evaporation capacity is 0.78m³/h.In order to improve the solid content of concentrate in the 2nd MVR vaporising devices 1, will be evaporated in the 2nd MVR vaporising devices 1 The first mother liquor of part afterwards is recycled to the 4th heat-exchanger rig 34 as second circulation liquid by the 7th circulating pump 77, then again into Enter the 2nd MVR vaporising devices 1 and carries out the second evaporation (reflux ratio 9.6).The second obtained steam containing ammonia is evaporated by the second pressure (18 DEG C of temperature rise) passes sequentially through the 4th heat-exchanger rig 34 and third heat-exchanger rig 33 after contracting machine 102 compresses, respectively with second The liquid of steam condensation containing ammonia, the second steam containing ammonia carry out heat exchange, and cooling obtains the second ammonium hydroxide, and is deposited in the second tank used for storing ammonia 52 Storage.The degree evaporated by the mass flowmenter pair second being arranged on the 2nd MVR vaporising devices 1 is monitored, and control second is steamed Send out a concentration of 0.9935X (306.5g/L) of concentrate sodium chloride.

Second concentrate of above-mentioned sulfur acid sodium crystal is sent into the second equipment for separating liquid from solid 92 (centrifuge) and carries out solid-liquid Separation, obtains 6.70m per hour³Contain NaCl 306.5g/L, Na₂SO₄ 52.5g/L、NaOH 2.89g/L、NH₃ 0.01g/L The second mother liquor, be temporarily stored into the second mother liquor tank 54.Second mother liquor is all recycled to first by the 9th circulating pump 79 to change Waste pipe between thermal 31 and the second heat-exchanger rig 32 is mixed to get pending waste water with catalyst production waste water.Solid-liquid Separating obtained solid sodium sulfate (obtains the sulfate crystal filter cake 349.84kg that water content is 14 mass %, wherein chlorine per hour The content for changing sodium is 3.9 mass % or less) with after the elution of the metabisulfite solution of the 52.5g/L equal with sodium sulphate butt quality, It is dry in drying machine, sodium sulphate 300.87kg (purity is 99.5 weight %) is obtained per hour, and cleaning solution passes through the tenth cycle Pump 80 is recycled to the 2nd MVR vaporising devices 1.

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

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

Embodiment 2

The processing of catalyst production waste water is carried out according to the method for embodiment 1, unlike：To contain NaCl 58g/L, Na₂SO₄ 120g/L、NH₄Cl 19g/L、(NH₄)₂SO₄The catalyst production waste water that 40g/L, pH are 7.1 is handled, and is obtained Pending waste water in the SO that contains₄ ^2-And Cl^-Molar ratio be 1：8.665.It is exchanged heat and is filled by the first heat-exchanger rig 31 and the 5th The temperature for setting 35 carry out heat exchange rear catalysts production waste water is 97 DEG C, waits locating after carrying out heat exchange by the second heat-exchanger rig 32 The temperature for managing waste water is 97.5 DEG C.The evaporation conditions of first MVR vaporising devices 2 include：Temperature be 100 DEG C, pressure be- 22.83kPa, evaporation capacity 3.47m³/h.The temperature of low-temperature treatment is 25 DEG C, residence time 55min.2nd MVR evaporation dresses The evaporation conditions for setting 1 include：Temperature is 95 DEG C, and pressure is -36.36kPa, evaporation capacity 2.28m³/h。

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

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

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

Embodiment 3

The processing of catalyst production waste water is carried out according to the method for embodiment 1, unlike：To contain NaCl 80g/L, Na₂SO₄ 78g/L、NH₄Cl 29g/L、(NH₄)₂SO₄The catalyst production waste water that 28.7g/L, pH are 6.6 is handled, and is obtained Pending waste water in the SO that contains₄ ^2-And Cl^-Molar ratio be 1：8.745.It is exchanged heat and is filled by the first heat-exchanger rig 31 and the 5th The temperature for setting 35 carry out heat exchange rear catalysts production waste water is 105 DEG C, is waited for after carrying out heat exchange by the second heat-exchanger rig 32 The temperature for handling waste water is 117 DEG C.The evaporation conditions of first MVR vaporising devices 2 include：Temperature is 110 DEG C, and pressure is 11.34kPa, evaporation capacity 4.26m³/h.The evaporation conditions of 2nd MVR vaporising devices 1 include：Temperature be 100 DEG C, pressure be- 22.82kPa, evaporation capacity 1.40m³/h.The temperature of low-temperature treatment is 20 DEG C, residence time 60min.

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

Second equipment for separating liquid from solid 92 obtains the sulfate crystal filter cake 632.55kg that water content is 14 mass % per hour, It is final to obtain sodium sulphate 543.99kg per hour (purity is 99.5 weight %)；12.39m is obtained per hour³, a concentration of NaCl 306.1g/L、Na₂SO₄ 53.9g/L、NaOH 1.85g/L、NH₃The second mother liquor of 0.0099g/L.

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

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

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

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

Claims

1. a kind of processing method of 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) pending waste water is passed through the first evaporation of the first MVR vaporising devices progress and obtains the first steam containing ammonia and sulfur acid sodium crystalline substance First concentrate of body and sodium chloride crystal, the pending waste water contain the catalyst production waste water；

2) the first concentrate of the sulfur acid sodium crystal and sodium chloride crystal is subjected to low-temperature treatment, keeps sodium sulfate crystal molten Solution, obtains the treatment fluid of sodium chloride-containing crystal；

3) treatment fluid of the sodium chloride-containing crystal is carried out first to be separated by solid-liquid separation, and is separated by solid-liquid separation obtained liquid phase by first and leads to Enter to carry out the second evaporation in the 2nd MVR vaporising devices to obtain the second concentrate of the second steam containing ammonia and sulfur acid sodium crystal；

Wherein, before the pending waste water is passed through the first MVR vaporising devices, the pH value for adjusting the pending waste water is big In 9；

Second evaporation makes sodium chloride crystal not crystallize precipitation；

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

2. according to the method described in claim 1, wherein, the pending waste water is the catalyst production waste water；Alternatively, institute State the liquid phase that pending waste water contains the catalyst production waste water and second separation of solid and liquid obtains；

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

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

Preferably, before the pending waste water is passed through the first MVR vaporising devices, the pH value of the pending waste water is adjusted More than 10.8；

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

3. method according to claim 1 or 2, wherein first evaporation makes the concentration of sodium sulphate in the treatment fluid For Y or less, wherein Y is sulfuric acid when sodium chloride and sodium sulphate reach saturation in treatment fluid under conditions of low-temperature treatment The concentration of sodium；

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

8. according to the method described in claim 1, wherein, before the pending waste water is passed through the first MVR vaporising devices, First steam containing ammonia is subjected to the first heat exchange with the pending waste water and obtains the first ammonium hydroxide；

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

Preferably, first steam containing ammonia remaining tail gas is condensed by first heat exchange to discharge after removing ammonia.

9. according to the method described in claim 1, wherein, the second steam containing ammonia that the 2nd MVR vaporising devices evaporate Obtained liquid phase is separated by solid-liquid separation with described first to carry out the second heat exchange and obtain the second ammonium hydroxide；

Preferably, the second steam containing ammonia remaining tail gas is condensed by second heat exchange to discharge after removing ammonia.

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

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

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

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

12. according to the method described in any one of claim 1-9, wherein NH in the 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 concentrated.