CN109095732A - A kind of technique based on magnesium processes desulfurization wastewater high-purity magnesium hydroxide - Google Patents

A kind of technique based on magnesium processes desulfurization wastewater high-purity magnesium hydroxide Download PDF

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CN109095732A
CN109095732A CN201811274426.0A CN201811274426A CN109095732A CN 109095732 A CN109095732 A CN 109095732A CN 201811274426 A CN201811274426 A CN 201811274426A CN 109095732 A CN109095732 A CN 109095732A
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magnesium
desulfurization wastewater
purity
hydroxide
technique
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CN109095732B (en
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刘松涛
胡杨林
陈传敏
岳立毅
王宇
柳文婷
孙明坤
张茹婷
袁维乾
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NANJING DANHENG TECHNOLOGY Co Ltd
North China Electric Power University
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NANJING DANHENG TECHNOLOGY Co Ltd
North China Electric Power University
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    • CCHEMISTRY; METALLURGY
    • C02TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02FTREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F9/00Multistage treatment of water, waste water, or sewage
    • CCHEMISTRY; METALLURGY
    • C01INORGANIC CHEMISTRY
    • C01FCOMPOUNDS OF THE METALS BERYLLIUM, MAGNESIUM, ALUMINIUM, CALCIUM, STRONTIUM, BARIUM, RADIUM, THORIUM, OR OF THE RARE-EARTH METALS
    • C01F5/00Compounds of magnesium
    • C01F5/14Magnesium hydroxide
    • C01F5/22Magnesium hydroxide from magnesium compounds with alkali hydroxides or alkaline- earth oxides or hydroxides
    • CCHEMISTRY; METALLURGY
    • C01INORGANIC CHEMISTRY
    • C01PINDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2006/00Physical properties of inorganic compounds
    • C01P2006/80Compositional purity
    • CCHEMISTRY; METALLURGY
    • C02TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02FTREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00Treatment of water, waste water, or sewage
    • C02F1/28Treatment of water, waste water, or sewage by sorption
    • C02F1/281Treatment of water, waste water, or sewage by sorption using inorganic sorbents
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    • C02TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02FTREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00Treatment of water, waste water, or sewage
    • C02F1/28Treatment of water, waste water, or sewage by sorption
    • C02F1/283Treatment of water, waste water, or sewage by sorption using coal, charred products, or inorganic mixtures containing them
    • CCHEMISTRY; METALLURGY
    • C02TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02FTREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00Treatment of water, waste water, or sewage
    • C02F1/44Treatment of water, waste water, or sewage by dialysis, osmosis or reverse osmosis
    • C02F1/442Treatment of water, waste water, or sewage by dialysis, osmosis or reverse osmosis by nanofiltration
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    • C02TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02FTREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00Treatment of water, waste water, or sewage
    • C02F1/46Treatment of water, waste water, or sewage by electrochemical methods
    • C02F1/461Treatment of water, waste water, or sewage by electrochemical methods by electrolysis
    • C02F1/463Treatment of water, waste water, or sewage by electrochemical methods by electrolysis by electrocoagulation
    • CCHEMISTRY; METALLURGY
    • C02TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02FTREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00Treatment of water, waste water, or sewage
    • C02F1/52Treatment of water, waste water, or sewage by flocculation or precipitation of suspended impurities
    • C02F1/5236Treatment of water, waste water, or sewage by flocculation or precipitation of suspended impurities using inorganic agents
    • CCHEMISTRY; METALLURGY
    • C02TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02FTREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00Treatment of water, waste water, or sewage
    • C02F1/72Treatment of water, waste water, or sewage by oxidation
    • CCHEMISTRY; METALLURGY
    • C02TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02FTREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00Treatment of water, waste water, or sewage
    • C02F1/72Treatment of water, waste water, or sewage by oxidation
    • C02F1/78Treatment of water, waste water, or sewage by oxidation with ozone
    • CCHEMISTRY; METALLURGY
    • C02TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02FTREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F2101/00Nature of the contaminant
    • C02F2101/10Inorganic compounds
    • C02F2101/16Nitrogen compounds, e.g. ammonia
    • CCHEMISTRY; METALLURGY
    • C02TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02FTREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F2103/00Nature of the water, waste water, sewage or sludge to be treated
    • C02F2103/18Nature of the water, waste water, sewage or sludge to be treated from the purification of gaseous effluents
    • CCHEMISTRY; METALLURGY
    • C02TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02FTREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F3/00Biological treatment of water, waste water, or sewage
    • C02F3/02Aerobic processes

Abstract

The present invention provides a kind of techniques based on magnesium processes desulfurization wastewater high-purity magnesium hydroxide, pass through the aeration of pretreatment stage, electric flocculation, oil removing, desulfurization wastewater is pre-processed except ammonia nitrogen and except processes such as COD, salt phase is divided to separate the calcium ion of the overwhelming majority and a part of magnesium ion by way of adding double alkali in dosing, then by nanofiltration separation monovalent ion and divalent ion, to obtain high magnesium ion concentration solution, magnesium hydrate precipitate is obtained by adding sodium hydroxide in magnesium recovery stage, then the processing such as precipitating filtration drying dehydration are obtained into the very high magnesium hydroxide products of purity, its purity is 99.83% after measured;Present invention process process is short, economic and environment-friendly, and the recycling of resource is realized during desulfurization wastewater processing.

Description

A kind of technique based on magnesium processes desulfurization wastewater high-purity magnesium hydroxide
Technical field
The present invention relates to technical field of waste water processing, and in particular to one kind is based on magnesium processes desulfurization wastewater high-purity hydrogen-oxygen The technique for changing magnesium.
Background technique
In thermal power plant's water treatment system, the degree of reliability of magnesium processes desulfurization wastewater treatment system equipment is increasingly by weight Depending on.China's magnesium resource is abundant, and wet-type magnesium method flue gas desulfurization technique passes through the research and development of more than ten years at home, technology can Feasibility by property, construction and the economy of operation and desulfurizing byproduct recycling has obtained extensive approval, has wide Development prospect.Wet-type magnesium method flue gas desulfurization technique is the slurries with magnesia after aquation, and main component is magnesium hydroxide, is made For absorbent absorb flue gas in sulfur dioxide, sulfur removal technology principle is substantially consistent with calcium oxide wet desulfurizing process, flue gas from The lower part of desulfurization reaction tower is in contact during rising in reaction tower with magnesium hydroxide slurry radially into reaction tower, cigarette Sulfur dioxide is reacted with magnesium hydroxide in gas generates magnesium sulfite to achieve the effect that desulfurization, while the SO contained in flue gas2、 The pernicious gases such as HCl and HF are also absorbed in absorption tower and dissolve in slurries.With the consumption of magnesium hydroxide in desulfurizing tower, pH value It will reduce, a large amount of desulfurization wastewaters for needing constantly to fill into fresh slurry to desulfurizing tower, and then being generated after desulfurization.Magnesium processes desulfurization is useless Contain a large amount of gypsum, flying dust, sulfate suspended particulate in water, the concentration of chloride ion is more up to 20000mg/L, magnesium processes desulfurization Cation in waste water is mainly Mg2+, also contain sub-fraction Ca2+With a small amount of heavy metal ion, direct emission can give environment band Carry out secondary pollution, and magnesium processes desulfurization wastewater " zero-emission " technological means is expensive and gimmick is still immature, common power plant can not It undertakes.If carrying out resource utilization to the ion contained in magnesium processes desulfurization wastewater by reasonable manner, environment is completed While protective duty, significant economic benefit also is brought to enterprise, this has great significance for our environmentalists.
Contain a large amount of magnesium ion in magnesium processes desulfurization wastewater, may be used as the raw material for preparing magnesium hydroxide.Magnesium hydroxide With alkalescent, resiliency is big, pyrolytic is good, it is active it is big, adsorption capacity is strong, nontoxic smokeless property, in all many-sided performances Excellent performance out is widely used in the fields such as acid waste water processing, ceramic material, inorganic fire retardants, flue gas desulfurization, hydroxide Magnesium powder body is in addition to general kind, and various dedicated, Compositional type new products emerge in multitude, and application field is extensive.
Producing high purity magnesium hydrate as raw material using magnesium processes desulfurization wastewater has the inherent advantage that raw material cost is low, both creates Economic benefit has been made, and has reduced environmental pollution.With tradition prepare the raw material of magnesium hydroxide compared with, magnesium processes desulfurization wastewater at Point complexity, in addition to magnesium ion, also containing the substances such as a large amount of sodium, potassium, calcium ion and a small amount of sulfate radical, carbonate, silicate, During preparing high purity magnesium hydrate using magnesium processes desulfurization wastewater, it is necessary to remove therein to preparation reaction and finished product The impurity composition that the technological operations such as purifying adversely affect, low-cost impurity removal process especially easy to operate.Magnesium hydroxide Product particle has biggish surface energy and surface polarity and is easy to happen reunion.The present invention specifically addresses above-mentioned problems, mention A kind of method preparing high purity magnesium hydrate using magnesium processes desulfurization wastewater out.
Summary of the invention
In order to solve the above technical problems, the present invention provides one kind to be based on magnesium processes desulfurization wastewater high-purity magnesium hydroxide Technique, the salinity in magnesium processes desulfurization wastewater is purified by three phases, magnesium processes magnesium processes desulfurization wastewater is enable to provide Sourceization utilizes, and reaches economic and environmental protection benefit.
Used technical solution is as follows to solve above-mentioned technical problem by the present invention:
The present invention includes the following steps:
(1) pretreatment stage:
Pre-treatment is carried out to desulfurization wastewater, by reproducibility ionic oxide formation, while except COD and removing ammonia nitrogen;
(2) dosing divides salt phase:
Sodium carbonate and sodium hydroxide are added into the waste water Jing Guo pre-treatment, is obtained containing magnesium hydroxide and precipitation of calcium carbonate Suspension, precipitation and separation and supernatant after ageing;
(3) magnesium recovery stage:
Supernatant main component is magnesium sulfate and sodium chloride solution, is carried out nanofiltration, and producing water side cation is mainly Na+, concentrated water side cation is mainly Mg2+;Concentrated water side is added into sodium hydroxide, obtains magnesium hydrate precipitate, precipitation and separation and supernatant Liquid obtains high purity magnesium hydrate product after precipitating filtration drying dehydration.Waste water after softening is passed into nanofiltration system during this System is to carry out monovalence with bivalent ions and separate, and producing water side cation is mainly Na+, concentrated water side cation is mainly Mg2 +, produce water side and be fed directly to NaCl reclaiming system.
As a further improvement of the present invention, the pretreatment stage includes aeration process, electric flocculation process, oil removing Journey removes ammonia nitrogen and removes COD process.The aeration process is using blast aeration, when desulfurization wastewater flows through aeration oxidation pool, Aerating oxidation bottom of pond portion is equipped with blower, can carry out blast aeration, on the one hand maintains the suspended matter state of raw water, reduces raw water COD, can be by the NH in magnesium processes desulfurization wastewater by magnesium processes desulfurization wastewater progress Air Exposure3- N and small organic molecule stripping are extremely In atmosphere, on the other hand the reproducibility ion sulfite ion etc. in magnesium processes magnesium processes desulfurization wastewater can also be oxidized to sulfuric acid Radical ion.
As a further improvement of the present invention, the flocculant during the electric flocculation is anion-polyacrylamide wadding Solidifying agent.Electric flocculation process can further remove the COD in raw water.Since concentration of suspension is higher in desulfurization wastewater, first Flocculation treatment is carried out to desulfurization wastewater.Flocculation can effectively remove lime stone, gypsum particle and silica of tail end wastewater etc. Suspended particulate.Flocculant uses anion-polyacrylamide, flocculant usage 20mg/L, mixing time 30min, reaction System temperature is 50~60 DEG C.
As a further improvement of the present invention, using except oleoresin is as filter medium in the oil removal process.Magnesium processes are de- Oily substance in sulphur waste water can dirty stifled nanofiltration membrane treatment system and make its can not normal table operation, therefore need to be in pretreatment rank Oily substance is removed by section.Except oil reactor is to utilize lipophilic group in resin using except oleoresin is as filter medium It collects and adsorbs the oil emulsion and oil droplet in magnesium processes desulfurization wastewater, when resin surface oil reservoir reaches certain thickness, in flow dynamic Under repulsive interaction with hydrophilic radical in resin, oil droplet is detached from resin, the water surface is floated up to, to achieve the purpose that water-oil separating.
As a further improvement of the present invention, described to have ammonia nitrogen compared with strong selectivity adsorption capacity except ammonia nitrogen uses in the process Zeolite.This kind of zeolite adsorbs ammonia nitrogen stage chemical formula are as follows:
Z·M+nNH3-H→Z·nNH4+M (1)
In formula, Z is zeolite;M is zeolite heavy metal cation;N is the number of nuclear charges;
As a further improvement of the present invention, described except COD uses modified activated carbon as filling in the process, before reaction Ozone is filled with to be pre-oxidized.Except COD reactor is except filling-modified active carbon in COD reactor, into reactor before add O3 It is pre-oxidized.The process is using O3Method associated with oxidation and bioactivity char filter, by O3Chemical oxidation, active carbon object 3 kinds of Physicochemical absorption, oxidation degradation technologies are integrated.Main purpose is to remove micro organic component in waste water and go back Originality salt.O is carried out before biological activated carbon adsorbs3Pre-oxidation, on the one hand can in preliminary oxidation water organic component and its His reproducibility salt, to reduce the organic loading of bioactivity char filter;On the other hand, O3Pre-oxidation can make the difficult biology in part Degradation of organic substances is changed into easily biological-degradable substance, to improve the biodegradability of bioactivity char filter water inlet.
As a further improvement of the present invention, the dosing, which divides in salt phase, adds after sodium carbonate removes a small amount of calcium ion Sodium hydroxide is added to adjust pH to 7.5-8.5, while having a small amount of magnesium ion precipitating, send bottom sediment to pipe after ageing Formula membranous system is sent again after being filtered to plate and frame filter press drying and dehydrating, obtains calcium carbonate and magnesium hydrate precipitate.This stage hair Raw chemical reaction is as follows:
Ca2++CO3 2-→CaCO3↓ (2)
Mg2++2OH-→Mg(OH)2↓ (3)
Mud mixed liquor in reaction tank is come out filtering slurry by tubular type membrane filtration system, is followed by plate and frame filter press Reason, moisture reuse, final product CaCO3With Mg (OH)2Mixture, can reuse to desulphurization system.
Compared with prior art, the present invention has the following technical effect that
The present invention precipitates calcium ion by adding double alkali, using obtaining a small amount of hydrogen of miscella after tubular type UF membrane The calcium carbonate solid product of magnesia, calcium carbonate are the important source materials in desulfurization process, as medicament reuse to desulfurization work The processing that calcium ion not only may be implemented in sequence can also reduce cost.
Magnesium hydroxide is a kind of important industrial chemicals, and traditional preparation process is using U.S. water chestnut mine as raw material system It is standby, complex process, and U.S. water chestnut mine can not be exploited infinitely, the present invention is with desulfurization wastewater as a kind of non-renewable resources The preparation of magnesium hydroxide is carried out for raw material, and the product purity prepared is very high, can satisfy the use standard of multiple use, no The further softening to desulfurization wastewater is only realized, also adds economic benefit, realizing turns waste into wealth.
The present invention is by carrying out substep purification to desulfurization wastewater, softening step by step, and final fresh water water quality obtained is excellent, completely The standard for meeting industrial water can be used as industrial water reflux and use, water resource is greatly saved.The present invention is in softening desulfurization The byproduct with economic value is converted by the calcium ions and magnesium ions in desulfurization wastewater during waste water, realizes the synthesis of resource It utilizes.
Detailed description of the invention
Attached drawing 1 is process flow chart of the invention.
Specific embodiment
The technical scheme in the embodiments of the invention will be clearly and completely described below, it is clear that described implementation Example is only a part of the embodiment of the present invention, instead of all the embodiments.Based on the embodiments of the present invention, this field is common Technical staff's every other embodiment obtained without making creative work belongs to the model that the present invention protects It encloses.
The present invention includes the following steps:
(1) pretreatment stage:
Pre-treatment is carried out to desulfurization wastewater, by reproducibility ionic oxide formation, while except COD and removing ammonia nitrogen;
(2) dosing divides salt phase:
Sodium carbonate and sodium hydroxide are added into the waste water Jing Guo pre-treatment, is obtained containing magnesium hydroxide and precipitation of calcium carbonate Suspension, precipitation and separation and supernatant after ageing;
(3) magnesium recovery stage:
Supernatant main component is magnesium sulfate and sodium chloride solution, is carried out nanofiltration, production water side is sodium chloride solution, dense Water side is high-concentration sulfuric acid magnesium solution;Concentrated water side is added into sodium hydroxide, obtains magnesium hydrate precipitate, precipitation and separation and supernatant Liquid, precipitating obtain high purity magnesium hydrate product after tubular membrane filters after drying and dehydrating.It will be useless after softening during this Water passes to nanofiltration system, is to carry out monovalence with bivalent ions and separate, producing water side cation is mainly Na+, concentrated water side sun Ion is mainly Mg2+.Supernatant after separating magnesium hydrate precipitate during this is back to nanofiltration system and carries out nanofiltration again, with Improve yield.
The pretreatment stage includes aeration process, electric flocculation process, oil removal process, removes ammonia nitrogen and except COD process.It is described Aeration process using blast aeration, when desulfurization wastewater flows through aeration oxidation pool, aerating oxidation bottom of pond portion is equipped with blower, can Blast aeration is carried out, the suspended matter state of raw water is on the one hand maintained, reduces the COD of raw water, magnesium processes desulfurization wastewater is aerated Processing can by magnesium processes desulfurization wastewater NH3-N and small organic molecule stripping into atmosphere, on the other hand can also be by magnesium Reproducibility ion sulfite ion in method magnesium processes desulfurization wastewater etc. is oxidized to sulfate ion.
Flocculant during the electric flocculation is anion-polyacrylamide flocculant.Electric flocculation process can be into one COD in the removal raw water of step.Since concentration of suspension is higher in desulfurization wastewater, flocculation treatment is carried out to desulfurization wastewater first. Flocculation can effectively remove the suspended particulates such as the lime stone, gypsum particle and silica of tail end wastewater.Flocculant using yin from Subtype polyacrylamide, flocculant usage 20mg/L, mixing time 30min, temperature of reaction system are 50~60 DEG C.
As a further improvement of the present invention, using except oleoresin is as filter medium in the oil removal process.Magnesium processes are de- Oily substance in sulphur waste water can dirty stifled nanofiltration membrane treatment system and make its can not normal table operation, therefore need to be in pretreatment rank Oily substance is removed by section.Except oil reactor is to utilize lipophilic group in resin using except oleoresin is as filter medium It collects and adsorbs the oil emulsion and oil droplet in magnesium processes desulfurization wastewater, when resin surface oil reservoir reaches certain thickness, in flow dynamic Under repulsive interaction with hydrophilic radical in resin, oil droplet is detached from resin, the water surface is floated up to, to achieve the purpose that water-oil separating.
It is described to have the zeolite compared with strong selectivity adsorption capacity to ammonia nitrogen except ammonia nitrogen uses in the process.This kind of zeolite adsorbs ammonia nitrogen Stage chemical formula are as follows:
Z·M+nNH3-H→Z·nNH4+M (1)
In formula, Z is zeolite;M is zeolite heavy metal cation;N is the number of nuclear charges;
It is described to be filled except COD uses modified activated carbon to be used as in the process, it is filled with ozone crystal form before reaction and pre-oxidizes.It removes COD reactor except filling-modified active carbon in COD reactor, into reactor before add O3It is pre-oxidized.The process is to adopt Use O3Method associated with oxidation and bioactivity char filter, by O3Chemical oxidation, active carbon physical and chemical adsorption, biological oxidation drop 3 kinds of technologies are solved to be integrated.Main purpose is micro organic component and reproducibility salt in removal waste water.In biological activated carbon O is carried out before absorption3Pre-oxidation, on the one hand can be with the organic component and other reproducibility salts in preliminary oxidation water, to reduce life The organic loading of object active carbon filter;On the other hand, O3Pre-oxidation can make part refractory organic be changed into easy life Object degradation material, to improve the biodegradability of bioactivity char filter water inlet.
The dosing divides in salt phase add sodium hydroxide and sodium carbonate after remove adjust after a small amount of calcium ion pH to Bottom sediment is sent to tubular type membranous system after ageing and is sent again after being filtered by 7.5-8.5, while having a small amount of magnesium ion precipitating To plate and frame filter press drying and dehydrating, calcium carbonate and magnesium hydrate precipitate are obtained.The chemical reaction that this stage occurs is as follows:
Ca2++CO3 2-→CaCO3↓ (2)
Mg2++2OH-→Mg(OH)2↓ (3)
Mud mixed liquor in reaction tank is come out filtering slurry by tubular type membrane filtration system, is followed by plate and frame filter press Reason, moisture reuse, final product CaCO3With Mg (OH)2Mixture, can reuse to desulphurization system.
Technical solution of the present invention is further elaborated below in conjunction with specific embodiment.
Embodiment 1:
The present embodiment is tested by preparing waste water identical with magnesium processes desulfurization wastewater ingredient.
Equipment used in simulation flowchart has the aeration of ton bucket, bottom equipped with air blower for storing desulfurization wastewater Oil reactor is removed, for except ammonia nitrogen is except ammonia nitrogen reactor, ozone occur for the flocculation basin of electric flocculation, for oil removing in pond Device, for except COD except COD reactor, the calcium sulfate precipitation pond for generating calcium sulfate, for precipitating to be dried and dehydrated Plate and frame filter press, nanofiltration system, Mg (OH)2Sedimentation basin, tubular type membranous system and plate and frame filter press.These equipment are commercially available Product, specific structure and application method are the prior art, and this will not be repeated here.
In experimentation, simulating calcium ion concentration in magnesium processes desulfurization wastewater is 400mg/L, magnesium ion concentration 5000mg/ L, sulfate ion concentration 12000mg/L, chlorine ion concentration 28769mg/L, COD concentration are 1550mg/L, and TDS concentration is 138500mg/L, ammonia nitrogen concentration 2076mg/L, pH control is between 5.75-6.92.
The magnesium processes desulfurization wastewater 1t that drainage comes is imported in process system of the invention, is taken at pre-treating technology section end Sample measurement, pre-treatment have apparent removal effect to COD, TDS, ammonia nitrogen.The high-pressure pump on ton bucket top is opened, waste water is passed through place Reason system, will aeration bottom of pond portion blower open, continue aeration quantity be 10L/min, open electric flocculation device, flocculant using yin from Subtype polyacrylamide, flocculant usage 20mg/L, mixing time 30min, temperature of reaction system are 50~60 DEG C.
Ozone generator is opened, control valve controls ozone ventilatory capacity in 25m3/L。
In CaCO3Soda ash Na is added in sedimentation basin2CO3, dosage 1325mg/L, and with Na (OH) adjust PH to 7.0~ 8.5
The chemical reaction that this stage occurs is as follows
Ca2++CO3 2-→CaCO3
Mg2++2OH-→Mg(OH)2
It adds every time and stands 10~15min, after fully reacting to be precipitated, CaCO later3Mud in reaction tank is sent to pipe Formula membranous system is filtered processing, the mud after the completion of filtering send to plate and frame filter press filters pressing after as gypsum, can reuse to de- In sulphur system.
Desulfurization wastewater after softening carries out a point salt by nanofiltration system.The NaCl for dividing salt to produce water side output after the completion produces water It is fed directly to reclaiming system;The nanofiltration system rate of recovery is set as 70%, i.e. production water side output water and source water water ratio, is produced from concentrated water side MgSO out4Mg in concentrated water2+Concentration increases to 16666.6mg/L, and concentrated water is passed through Mg (OH)2It after in sedimentation basin, adds Na (OH), adjusts PH to 11 is saved, is generated Mg (OH)2Precipitating is reacted as follows:
Mg2++2OH-→Mg(OH)2
To which after reaction, mixed liquor is passed through tubular type membranous system and is filtered processing, production water side reuse to nanofiltration system, mud Slurry is by being made solid Mg (OH) through plate and frame filter press after tubular membrane filtering2, its purity is 99.83% after measured.
Embodiment described above is only that preferred embodiment of the invention is described, and is not carried out to the scope of the present invention It limits, without departing from the spirit of the design of the present invention, those of ordinary skill in the art make technical solution of the present invention Various changes and improvements, should all fall into claims of the present invention determine protection scope in.

Claims (8)

1. a kind of technique based on magnesium processes desulfurization wastewater high-purity magnesium hydroxide, which comprises the steps of:
(1) pretreatment stage:
Pre-treatment is carried out to desulfurization wastewater, by reproducibility ionic oxide formation, while except COD and removing ammonia nitrogen;
(2) dosing divides salt phase:
To NaOH solution is added after first adding sodium carbonate liquor in the waste water of pre-treatment, pH to 7.5-8.5 is adjusted, is contained The suspension of magnesium hydroxide and precipitation of calcium carbonate, precipitation and separation and supernatant after ageing;
(3) magnesium recovery stage:
Supernatant main component is magnesium sulfate and sodium chloride solution, is carried out nanofiltration, and producing water side cation is mainly Na+, concentrated water Side cation is mainly Mg2+;Concentrated water side is added into sodium hydroxide, obtains magnesium hydrate precipitate, precipitation and separation and supernatant, is precipitated High purity magnesium hydrate product is obtained after filtration drying dehydration.
2. a kind of technique based on magnesium processes desulfurization wastewater high-purity magnesium hydroxide according to claim 1, feature It is, the pretreatment stage includes aeration process, electric flocculation process, oil removal process, removes ammonia nitrogen and except COD process.
3. a kind of technique based on magnesium processes desulfurization wastewater high-purity magnesium hydroxide according to claim 2, feature It is, the flocculant during the electric flocculation is anion-polyacrylamide flocculant.
4. a kind of technique based on magnesium processes desulfurization wastewater high-purity magnesium hydroxide according to claim 2, feature It is, using except oleoresin is as filter medium in the oil removal process.
5. a kind of technique based on magnesium processes desulfurization wastewater high-purity magnesium hydroxide according to claim 2, feature It is, it is described to have the zeolite compared with strong selectivity adsorption capacity to ammonia nitrogen except ammonia nitrogen uses in the process.
6. a kind of technique based on magnesium processes desulfurization wastewater high-purity magnesium hydroxide according to claim 2, feature It is, it is described except using modified activated carbon to be used as filling during COD, ozone, which is filled with, before reaction is pre-oxidized.
7. a kind of technique based on magnesium processes desulfurization wastewater high-purity magnesium hydroxide according to claim 1, feature Be, the dosing divides in salt phase add sodium hydroxide and sodium carbonate after remove a small amount of calcium ion after adjust pH to 7.5- 8.5, while having a small amount of magnesium ion precipitating, bottom sediment sent to tubular type membranous system after ageing and is sent again after being filtered to plate Frame filter press drying and dehydrating, obtains calcium carbonate and magnesium hydrate precipitate.
8. a kind of technique based on magnesium processes desulfurization wastewater high-purity magnesium hydroxide according to claim 1, feature It is, the concentrated water by nanofiltration separation obtains magnesium hydrate precipitate, sink by tubular type UF membrane by adding sodium hydroxide It forms sediment and supernatant, precipitating filtration drying obtains high purity magnesium hydrate product after being dehydrated.
CN201811274426.0A 2018-10-30 2018-10-30 Process for preparing high-purity magnesium hydroxide based on magnesium-method desulfurization wastewater Active CN109095732B (en)

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110386710A (en) * 2019-07-19 2019-10-29 北京朗新明环保科技有限公司南京分公司 A method of epsom salt is produced using heat-engine plant desulfurized waste water
CN111533319A (en) * 2020-05-20 2020-08-14 北方工业大学 Device and method for treating COD (chemical oxygen demand) in desulfurization wastewater by ozone oxidation method

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101016175A (en) * 2006-02-12 2007-08-15 山东滨化集团有限责任公司 Method of eliminating magnesium sulfate from magnesium sulfate containing waste water solution
CN104843927A (en) * 2015-05-26 2015-08-19 中国华电工程(集团)有限公司 Desulfurization waste water zero discharging process and system
CN105214474A (en) * 2015-10-22 2016-01-06 南通海容热能环境工程有限公司 A kind of flue gas desulfurization waste-water pretreatment system integrated with mud and technique thereof
CN105236659A (en) * 2015-11-06 2016-01-13 北京沃特尔水技术股份有限公司 Nanofiltration treatment method of desulfurization waste water
CN107500450A (en) * 2017-10-16 2017-12-22 北京廷润膜技术开发股份有限公司 Desulfurization wastewater zero-emission processing method
CN206799333U (en) * 2017-05-26 2017-12-26 西安热工研究院有限公司 A kind of Desulphurization for Coal-fired Power Plant waste water reclaiming system
CN108249646A (en) * 2018-03-20 2018-07-06 厦门嘉戎技术股份有限公司 Can resource recycling power plant desulfurization wastewater Zero-discharge treating process and device

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101016175A (en) * 2006-02-12 2007-08-15 山东滨化集团有限责任公司 Method of eliminating magnesium sulfate from magnesium sulfate containing waste water solution
CN104843927A (en) * 2015-05-26 2015-08-19 中国华电工程(集团)有限公司 Desulfurization waste water zero discharging process and system
CN105214474A (en) * 2015-10-22 2016-01-06 南通海容热能环境工程有限公司 A kind of flue gas desulfurization waste-water pretreatment system integrated with mud and technique thereof
CN105236659A (en) * 2015-11-06 2016-01-13 北京沃特尔水技术股份有限公司 Nanofiltration treatment method of desulfurization waste water
CN206799333U (en) * 2017-05-26 2017-12-26 西安热工研究院有限公司 A kind of Desulphurization for Coal-fired Power Plant waste water reclaiming system
CN107500450A (en) * 2017-10-16 2017-12-22 北京廷润膜技术开发股份有限公司 Desulfurization wastewater zero-emission processing method
CN108249646A (en) * 2018-03-20 2018-07-06 厦门嘉戎技术股份有限公司 Can resource recycling power plant desulfurization wastewater Zero-discharge treating process and device

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110386710A (en) * 2019-07-19 2019-10-29 北京朗新明环保科技有限公司南京分公司 A method of epsom salt is produced using heat-engine plant desulfurized waste water
CN111533319A (en) * 2020-05-20 2020-08-14 北方工业大学 Device and method for treating COD (chemical oxygen demand) in desulfurization wastewater by ozone oxidation method

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