阅读说明：本技术 一种清洁闭环生产氢氧化镁的方法及系统 (A kind of method and system cleaning loop production magnesium hydroxide ) 是由 马小龙 于 2019-09-27 设计创作，主要内容包括：本发明提供一种清洁闭环生产氢氧化镁的方法及系统,所述方法包括,氯碱生产步骤S1：饱和氯化钠溶液进入电解装置进行电解,生成氢氧化钠溶液、氯气、氢气、以及不饱和氯化钠溶液；盐析步骤S2：六水氯化镁晶体和所述不饱和氯化钠溶液进入盐析装置,析出氯化钠晶体,生成氯化镁溶液；氢氧化镁生产步骤S3：所述氯化镁溶液和所述氢氧化钠溶液进入氢氧化镁合成装置,反应生成第一浆料；所述第一浆料进入第一压滤机进行过滤洗涤,生成第一氢氧化镁滤饼和第一氯化钠滤液；所述第一氢氧化镁滤饼进行干燥后,得到氢氧化镁产品。根据本发明的技术方案,通过将氯碱工艺与氢氧化镁生产工艺相结合,能够实现资源的循环综合利用。(The present invention provides a kind of method and system for cleaning loop production magnesium hydroxide, the method includes, chlor-alkali production step S1: saturated sodium chloride solution enters electrolysis unit and is electrolysed, and generates sodium hydroxide solution, chlorine, hydrogen and unsaturated sodium chloride solution；Salting-out step S2: magnesium chloride hexahydrate crystal and the unsaturated sodium chloride solution enter salt analysis apparatus, and precipitated sodium chloride crystal generates magnesium chloride solution；Magnesium hydroxide production stage S3: the magnesium chloride solution and the sodium hydroxide solution enter magnesium hydroxide synthesizer, and reaction generates the first slurry；First slurry enters the first filter press and is filtered washing, generates the first magnesium hydroxide filter cake and the first sodium chloride filtrate；After the first magnesium hydroxide filter cake is dried, magnesium hydroxide products are obtained.According to the technique and scheme of the present invention, by combining chloralkali process with magnesium hydroxide production technology, the circulation comprehensive that can be realized resource is utilized.)

1. a kind of method for cleaning loop production magnesium hydroxide, including,

Chlor-alkali production step (S1):

Saturated sodium chloride solution is produced by salt dissolving device；

The saturated sodium chloride solution enters electrolysis unit and is electrolysed, and generates sodium hydroxide solution, chlorine, hydrogen and not Saturated sodium chloride solution；

Salting-out step (S2):

Magnesium chloride hexahydrate crystal and the unsaturated sodium chloride solution enter salt analysis apparatus, and precipitated sodium chloride crystal generates chlorination Magnesium solution；

The sodium chloride crystal returns to the salt dissolving device and carries out salt dissolving, to be deployed into the saturated sodium chloride solution；

Magnesium hydroxide production stage (S3):

The magnesium chloride solution and the sodium hydroxide solution enter magnesium hydroxide synthesizer, and reaction generates the first slurry；

First slurry enters the first filter press and is filtered washing, generates the first magnesium hydroxide filter cake and the filter of the first sodium chloride Liquid；

The first sodium chloride filtrate returns to the salt dissolving device and carries out salt dissolving, to be deployed into the saturated sodium chloride solution；

After the first magnesium hydroxide filter cake is dried, magnesium hydroxide products are obtained.

2. according to the method described in claim 1, the magnesium hydroxide production stage (S3) further includes, first magnesium hydroxide Filter cake passes through following steps before being dried:

The first magnesium hydroxide filter cake enters size-mixing tank and sizes mixing, and generates the second slurry；

Second slurry enters the second filter press and carries out pressure filtration washing, obtains the second magnesium hydroxide filter cake, the filter of the second sodium chloride Liquid and Washing of Filter Cake water；

The Washing of Filter Cake water returns to the size-mixing tank and sizes mixing to the first magnesium hydroxide filter cake；

The second magnesium hydroxide filter cake after drying, obtains magnesium hydroxide products.

3. according to the method described in claim 2, wherein, the second sodium chloride filtrate is containing residual magnesium ion, hydroxide The solution of magnesium and sodium chloride, the method also includes,

Water reuse (treatment processing step (S4):

The pH value for adjusting the second sodium chloride filtrate is 10~11, so that the magnesium ion in the second sodium chloride filtrate is formed Precipitating；

Magnesium hydroxide and the precipitating separated in the second sodium chloride filtrate is intercepted, sodium chloride clear solution is obtained；

The sodium chloride clear solution separates sodium chloride by reverse osmosis, obtains pure water；

The pure water enters at least one of first filter press, second filter press, as slurry.

4. according to the method described in claim 1, wherein, the first sodium chloride filtrate is containing residual magnesium ion, hydroxide The sodium chloride solution of magnesium, the method also includes the first sodium chloride filtrate is passed through at tail salt before returning to the salt dissolving device It manages step (S5):

The tail salt treatment step (S5) includes,

Hydrochloric acid, sodium hydroxide, coagulant, flocculant are sequentially added into the first sodium chloride filtrate, and after natural subsidence To the supernatant of magnesium hydroxide wadding body and sodium chloride-containing；

The supernatant of the sodium chloride-containing obtains third sodium chloride filtrate by the filtering of fabric filter to filter suspended matter；

The third sodium chloride filtrate returns to the salt dissolving device and carries out salt dissolving, to be deployed into the saturated sodium chloride solution.

5. according to the method described in claim 1, further include,

The part unsaturated sodium chloride solution enters the salt dissolving device after pervaporation, to be deployed into the saturated sodium-chloride Solution.

6. a kind of system for cleaning loop production magnesium hydroxide, including,

Salt dissolving device, for producing saturated sodium chloride solution；

Electrolysis unit is connected with the salt dissolving device, for receiving the saturated sodium chloride solution and being electrolysed to it, generates Sodium hydroxide solution, chlorine, hydrogen and unsaturated sodium chloride solution；

Salt analysis apparatus is connected with the electrolysis unit, for receiving the unsaturated sodium chloride solution and by itself and six water chlorinations Magnesium crystal mixing is saltoutd, and with precipitated sodium chloride crystal and generates magnesium chloride solution；

The salt dissolving device is also used to receive the sodium chloride crystal and carries out salt dissolving, to be deployed into the saturated sodium chloride solution；

Magnesium hydroxide synthesizer is connected, for receiving the magnesium chloride solution with the salt analysis apparatus and the electrolysis unit With the sodium hydroxide solution and reacted, generate the first slurry；

First filter press is connected with the magnesium hydroxide synthesizer and the salt dissolving device, for receiving first slurry And washing is filtered to it, generate the first magnesium hydroxide filter cake and the first sodium chloride filtrate；

The salt dissolving device is also used to receive the first sodium chloride filtrate and carries out salt dissolving, to be deployed into the saturated sodium-chloride Solution；

Drier is connected with first filter press, for receiving the first magnesium hydroxide filter cake and it being dried, obtains To magnesium hydroxide products.

7. system according to claim 6 further includes between first filter press and the drier,

Size-mixing tank is connected with first filter press, raw for receiving the first magnesium hydroxide filter cake and sizing mixing to it At the second slurry；

Second filter press is connected between the size-mixing tank and the drier, for receive second slurry and to its into Row pressure filtration washing obtains the second magnesium hydroxide filter cake, the second sodium chloride filtrate and Washing of Filter Cake water；

The size-mixing tank is also used to receive the Washing of Filter Cake water, to size mixing to the first magnesium hydroxide filter cake；

The drier obtains magnesium hydroxide products for receiving the second magnesium hydroxide filter cake and it being dried.

8. system according to claim 7, wherein the second sodium chloride filtrate is containing residual magnesium ion, hydroxide The solution of magnesium and sodium chloride, the system also includes,

Water reuse (treatment processing unit is connected with second filter press and first filter press, for receiving second chlorination Sodium filtrate and to adjust its pH value be 10~11, so that magnesium ion in the second sodium chloride filtrate forms precipitating；

It include ultrafiltration ceramic membrane in the water reuse (treatment processing unit, for intercepting the hydrogen-oxygen separated in the second sodium chloride filtrate Change magnesium and the precipitating, obtains sodium chloride clear solution；

It further include reverse osmosis membrane in the water reuse (treatment processing unit, for dividing the sodium chloride in the sodium chloride clear solution From to obtain pure water；And the pure water is returned at least one of first filter press, described second filter press, as Slurry.

9. system according to claim 6, wherein the first sodium chloride filtrate is containing residual magnesium ion, hydroxide The sodium chloride solution of magnesium, the system also includes,

Tail salt treatment device is connected between first filter press and the salt dissolving device, for receiving first chlorination Sodium filtrate simultaneously sequentially adds hydrochloric acid, sodium hydroxide, coagulant, flocculant thereto, and magnesium hydroxide wadding is obtained after natural subsidence The supernatant of body and sodium chloride-containing；

Further include fabric filter in the tail salt treatment device, is filtered for the supernatant to the sodium chloride-containing, with Suspended matter is filtered, third sodium chloride filtrate is obtained；

The salt dissolving device is also used to receive the third sodium chloride filtrate and carries out salt dissolving, to be deployed into the saturated sodium-chloride Solution.

10. according to the method described in claim 6, further include,

Vaporising device is connected with the electrolysis unit and the salt dissolving device, molten for unsaturation sodium chloride described in receiving portion Liquid is simultaneously evaporated it, then makes it into the salt dissolving device, to be deployed into the saturated sodium chloride solution.

Technical field

This patent disclosure relates generally to the comprehensive utilization of resources fields of inorganic chemical product, close more particularly, to a kind of cleaning Ring produces magnesium hydroxide technology.

Background technique

Magnesium hydroxide is to be only second to magnesia in magnesium chemicals and light calcined magnesia occupies the magnesium chemicals of third position, and close External magnesia refractories manufacturer adjusts the product mix over year, and in non-fire resistive material field, yield highest, kind are most, answer It with the most commonly used kind in field, while being also that developed country is pursuing the strategy of sustainable development, protect environment, sending out beneficial to ecology By one of favor and the product praised highly in exhibition process.Referred to as green safe neutralizer, environmental-friendly fire retardant and the third Alkali.Therefore, in addition to developed country continues to keep powerful growth momentum, some less developed countries also aim at this product, present The a piece of situation competitively developed.Production method mainly has 2 kinds, and one is being produced using natural crystal, another kind is chemical synthesis Method.Its purposes mainly has 4 kinds: (1) in environment protection field, being widely used in neutralizing acid waste water, flue gas desulfurization, processing containing heavy metal Waste liquid etc.；(2) in flame retardant area, it is used as the inorganic fire retardants of high polymer；(3) in terms of aquaculture, magnesium hydroxide can be made For alkalescent neutralizer, weaken acidification caused by farm accumulates because of organic matter and be inclined to, and it is thin to can inhibit sulfate reduction The breeding of bacterium；(4) in other respects, such as oil product vanadium-inhibiting agent, additive, electronic component or coating electronic ceramics field. Magnesium hydroxide, by more and more extensive concern, is the most hot magnesium compound field of Recent study in inorganic fire retardants field. Magnesium hydroxide is produced to be greater than and be asked, Market competition.

China's magnesium compound industry raw material is solvable mainly from magnesia nonmetallic ore, brine, Bischofite in Salt lake, magnesium sulfate Magnesium salts etc..As country renovates the environmental protection of mining and chemical company, most of magnesia nonmetallic ore is closed to prohibit and be adopted, magnesium Commodities company's industry is closed because lacking raw material and the environmental protection reasons such as not up to standard, face halt production or half is stopped production, such as Hebei silk floss river, Henan monarch ginseng, pellet Source Dong Jin etc..In order to alleviate magnesium compound production and the energy, resource scarcity, environmental pollution, the contradiction between ecological protection, the world Various comprehensive utilization of resources production methods efficiently, environmentally friendly, economic are all being studied by each state.With resource-effective, realization environment friend The Mode of Circular that good and sustainable development is characterized by countries in the world concern and take corresponding behave to increase one after another The ability of strong sustainable economic development.

Summary of the invention

It is an object of the invention to overcome the waste residue that production magnesium hydroxide generates in the prior art that cannot efficiently use, cause The defect of environmental pollution and the wasting of resources provides a kind of method and system for cleaning loop production magnesium hydroxide.

According to the first aspect of the invention, a kind of method cleaning loop production magnesium hydroxide is provided, including, chlor-alkali production Step S1: saturated sodium chloride solution is produced by salt dissolving device；The saturated sodium chloride solution enters electrolysis unit and is electrolysed, Generate sodium hydroxide solution, chlorine, hydrogen and unsaturated sodium chloride solution；Salting-out step S2: magnesium chloride hexahydrate crystal and institute It states unsaturated sodium chloride solution and enters salt analysis apparatus, precipitated sodium chloride crystal generates magnesium chloride solution；The sodium chloride crystal returns It returns the salt dissolving device and carries out salt dissolving, to be deployed into the saturated sodium chloride solution；Magnesium hydroxide production stage S3: the chlorination Magnesium solution and the sodium hydroxide solution enter magnesium hydroxide synthesizer, and reaction generates the first slurry；First slurry into Enter the first filter press and be filtered washing, generates the first magnesium hydroxide filter cake and the first sodium chloride filtrate；First sodium chloride Filtrate returns to the salt dissolving device and carries out salt dissolving, to be deployed into the saturated sodium chloride solution；The first magnesium hydroxide filter cake After being dried, magnesium hydroxide products are obtained.

Optionally, the magnesium hydroxide production stage S3 further includes that preceding warp is dried in the first magnesium hydroxide filter cake Cross following steps: the first magnesium hydroxide filter cake enters size-mixing tank and sizes mixing, and generates the second slurry；Second slurry into Enter the second filter press and carry out pressure filtration washing, obtains the second magnesium hydroxide filter cake, the second sodium chloride filtrate and Washing of Filter Cake water； The Washing of Filter Cake water returns to the size-mixing tank and sizes mixing to the first magnesium hydroxide filter cake；The second magnesium hydroxide filter Cake after drying, obtains magnesium hydroxide products.

Optionally, the second sodium chloride filtrate is the solution containing residual magnesium ion, magnesium hydroxide and sodium chloride, described Method further includes water reuse (treatment processing step S4: the pH value for adjusting the second sodium chloride filtrate is 10~11, so that described second Magnesium ion in sodium chloride filtrate forms precipitating；It intercepts and separates magnesium hydroxide in the second sodium chloride filtrate and described heavy It forms sediment, obtains sodium chloride clear solution；The sodium chloride clear solution separates sodium chloride by reverse osmosis, obtains pure water；It is described Pure water enters at least one of first filter press, second filter press, as slurry.

Optionally, the first sodium chloride filtrate is the sodium chloride solution containing residual magnesium ion, magnesium hydroxide, the side Method further includes that the first sodium chloride filtrate passes through tail salt treatment step S5: the tail salt treatment before returning to the salt dissolving device Step S5 includes sequentially adding hydrochloric acid, sodium hydroxide, coagulant, flocculant in Xiang Suoshu the first sodium chloride filtrate, and sink naturally The supernatant of magnesium hydroxide wadding body and sodium chloride-containing is obtained after drop；The supernatant of the sodium chloride-containing passes through the mistake of fabric filter Filter, to filter suspended matter, obtains third sodium chloride filtrate；The third sodium chloride filtrate returns to the salt dissolving device Salt, to be deployed into the saturated sodium chloride solution.

It optionally, further include that the part unsaturated sodium chloride solution enters the salt dissolving device after pervaporation, to adjust It is made into the saturated sodium chloride solution.

According to the second aspect of the invention, a kind of system cleaning loop production magnesium hydroxide is provided, including, salt dissolving dress It sets, for producing saturated sodium chloride solution；Electrolysis unit is connected, for receiving the saturated sodium-chloride with the salt dissolving device Solution is simultaneously electrolysed it, generates sodium hydroxide solution, chlorine, hydrogen and unsaturated sodium chloride solution；Salt analysis apparatus, It is connected with the electrolysis unit, for receiving the unsaturated sodium chloride solution and it being mixed progress with magnesium chloride hexahydrate crystal It saltouts, with precipitated sodium chloride crystal and generates magnesium chloride solution；The salt dissolving device, be also used to receive the sodium chloride crystal into Row salt dissolving, to be deployed into the saturated sodium chloride solution；Magnesium hydroxide synthesizer is filled with the salt analysis apparatus and the electrolysis It sets connected, for receiving the magnesium chloride solution and the sodium hydroxide solution and reacted, generates the first slurry；First pressure Filter is connected with the magnesium hydroxide synthesizer and the salt dissolving device, for receiving first slurry and carrying out to it Filtration washing generates the first magnesium hydroxide filter cake and the first sodium chloride filtrate；The salt dissolving device, is also used to receive described first Sodium chloride filtrate carries out salt dissolving, to be deployed into the saturated sodium chloride solution；Drier is connected with first filter press, uses In receiving the first magnesium hydroxide filter cake and it being dried, magnesium hydroxide products are obtained.

It optionally, further include size-mixing tank between first filter press and the drier, with the first filter press phase Even, for receiving the first magnesium hydroxide filter cake and sizing mixing to it, the second slurry is generated；Second filter press, is connected to Between the size-mixing tank and the drier, for receiving second slurry and carrying out pressure filtration washing to it, the second hydrogen is obtained Magnesia filter cake, the second sodium chloride filtrate and Washing of Filter Cake water；The size-mixing tank is also used to receive the Washing of Filter Cake water, To size mixing to the first magnesium hydroxide filter cake；The drier, for receiving the second magnesium hydroxide filter cake and right It is dried, and obtains magnesium hydroxide products.

Optionally, the second sodium chloride filtrate is the solution containing residual magnesium ion, magnesium hydroxide and sodium chloride, described System further includes water reuse (treatment processing unit, is connected with second filter press and first filter press, for receiving described Dichloride sodium filtrate and to adjust its pH value be 10~11, so that magnesium ion in the second sodium chloride filtrate forms precipitating；Institute Stating includes ultrafiltration ceramic membrane in water reuse (treatment processing unit, for intercepts separate magnesium hydroxide in the second sodium chloride filtrate with The precipitating obtains sodium chloride clear solution；Further include reverse osmosis membrane in the water reuse (treatment processing unit, is used for the chlorination Sodium chloride separation in sodium clear solution, to obtain pure water；And the pure water is returned into first filter press, second pressure At least one of filter, as slurry.

Optionally, the first sodium chloride filtrate is the sodium chloride solution containing residual magnesium ion, magnesium hydroxide, the system System further includes that tail salt treatment device is connected between first filter press and the salt dissolving device, for receiving described first Sodium chloride filtrate simultaneously sequentially adds hydrochloric acid, sodium hydroxide, coagulant, flocculant thereto, and hydroxide is obtained after natural subsidence The supernatant of magnesium wadding body and sodium chloride-containing；It further include fabric filter in the tail salt treatment device, for the chloride containing The supernatant of sodium is filtered, and to filter suspended matter, obtains third sodium chloride filtrate；The salt dissolving device, is also used to receive institute It states third sodium chloride filtrate and carries out salt dissolving, to be deployed into the saturated sodium chloride solution.

Optionally, further include vaporising device, be connected with the electrolysis unit and the salt dissolving device, be used for receiving portion The unsaturation sodium chloride solution is simultaneously evaporated it, makes it into the salt dissolving device, then to be deployed into the saturation Sodium chloride solution.

The present invention has the advantages that

1) according to the technique and scheme of the present invention, by combining chloralkali process with magnesium hydroxide production technology, Neng Gou Meet the comprehensive utilization that resource is realized while chlorine industry and magnesium hydroxide production requirement；

2) according to the technique and scheme of the present invention, the recycling by sodium compound in the entire system realizes sodium money The cyclic balance in source and effective use realize the clean manufacturing of entire technical process and the zero-emission of waste residue；

3) according to the technique and scheme of the present invention, by water reuse (treatment processing scheme, the recycling of washing water is realized, it is water-saving Significant effect.

Detailed description of the invention

Fig. 1 shows a kind of system schematic for cleaning loop production magnesium hydroxide according to the present invention.

Fig. 2 shows a kind of a kind of embodiment signals for the system for cleaning loop production magnesium hydroxide according to the present invention Figure.

Fig. 3 shows a kind of a kind of embodiment signal of system including water reuse (treatment processing unit according to the present invention Figure.

Fig. 4 shows a kind of a kind of embodiment schematic diagram of system including tail salt treatment device according to the present invention.

Fig. 5 shows a kind of a kind of embodiment schematic diagram of system including vaporising device according to the present invention.

Fig. 6 shows a kind of method flow diagram for cleaning loop production magnesium hydroxide according to the present invention.

Fig. 7 shows the grain size distribution of sodium chloride crystal according to the present invention.

Fig. 8 shows the grain size distribution of magnesium hydroxide products according to the present invention.

Specific embodiment

The preferred embodiments of the present invention will be described in detail with reference to the accompanying drawing, and reference label refers to the group in the present invention Part, technology, realizing under appropriate circumstances so as to advantages and features of the invention can be easier to be understood.Following description is pair The materialization of the claims in the present invention, and other specific implementations not clearly stated relevant to claim also belong to power The range that benefit requires.

Fig. 1 shows a kind of system schematic for cleaning loop production magnesium hydroxide according to the present invention.

As shown in Figure 1, a kind of system for cleaning loop production magnesium hydroxide is provided, including, salt dissolving device 110, for giving birth to Produce saturated sodium chloride solution；Electrolysis unit 120 is connected, for receiving the saturated sodium chloride solution with the salt dissolving device 110 And it is electrolysed, generate sodium hydroxide solution, chlorine, hydrogen and unsaturated sodium chloride solution；Salt analysis apparatus 130, with The electrolysis unit 120 is connected, for receiving the unsaturated sodium chloride solution and being mixed into it with magnesium chloride hexahydrate crystal Row is saltoutd, and with precipitated sodium chloride crystal and generates magnesium chloride solution；The salt dissolving device 110, is also used to receive the sodium chloride Crystal carries out salt dissolving, to be deployed into the saturated sodium chloride solution；Magnesium hydroxide synthesizer 140, with the salt analysis apparatus 130 It is connected with the electrolysis unit 120, for receiving the magnesium chloride solution and the sodium hydroxide solution and being reacted, generates The first slurry comprising magnesium hydroxide and sodium chloride；First filter press 150, with the magnesium hydroxide synthesizer 140 and described Salt dissolving device 110 is connected, for receiving first slurry and be filtered washing to it, generate the first magnesium hydroxide filter cake with First sodium chloride filtrate；The salt dissolving device 110 is also used to receive the first sodium chloride filtrate and carries out salt dissolving, to be deployed into The saturated sodium chloride solution；Drier 160 is connected with first filter press 150, for receiving first magnesium hydroxide Filter cake is simultaneously dried it, obtains magnesium hydroxide products.

The electrolysis unit 120 is electrolysed with saturated sodium chloride solution, can both accelerate reaction rate, also because of chlorine Meltage in saturated sodium chloride solution is smaller.The saturated sodium chloride solution in the electrolysis unit 120 can pass through The salt dissolving device 110 provides.The salt dissolving device 110 can be adjusts solid sodium chloride and water according to a certain percentage Match, is also possible to the solid sodium chloride and unsaturated sodium chloride solution such as deploy, to generate saturated sodium chloride solution.Example Such as, the salt dissolving device 110 can receive the sodium chloride crystal and first filter press that the salt analysis apparatus 130 generates 150 the first sodium chloride filtrates generated are deployed the circulation comprehensive benefit that sodium resource is realized to produce saturated sodium chloride solution With.The electrolysis unit 120 can be connected directly or be indirectly connected with the salt dissolving device 110.For example, the salt dissolving dress The saturated sodium chloride solution produced in 110 is set before being electrolysed into the electrolysis unit 120, can also be carried out as needed Removal of impurities, to remove the calcium ions and magnesium ions etc. in the saturated sodium chloride solution.

The salt analysis apparatus 130 is greater than the original of the solubility of sodium chloride according to common-ion effect and the solubility of magnesium chloride Reason, saltouts after mixing unsaturated sodium chloride solution with magnesium chloride hexahydrate crystal, precipitated sodium chloride crystal, magnesium chloride hexahydrate Crystal is dissolved in water and generates magnesium chloride solution, both can make to separate by the modes such as filtering, being centrifugated.The magnesium chloride solution The magnesium hydroxide synthesizer 140 can be entered back into after purified treatment.The purified treatment, which can be, utilizes ceramic membrane Etc. modes intercept the insoluble matter in solution.The magnesium chloride hexahydrate also known as water chlorine stone, halogen piece, halogen powder, chemical formula MgCl₂· 6H₂O may come from salt lake or produce the by-product of other products, such as by-product when production potash fertilizer.The unsaturation Sodium chloride solution can be the sodium chloride solution of the 203g/L generated after electrolysis saturated sodium chloride solution.The salt analysis apparatus 130 The unsaturated sodium chloride solution that the electrolysis unit 120 generates is utilized, fully utilizes part water, reduces the unsaturation The evaporation capacity of water in sodium chloride solution, greatly reduces energy consumption.

First slurry is the magnesium hydroxide and sodium chloride that reaction generates, and may not no fully reacting magnesium chloride Deng mixed slurry.After the filters pressing and washing of first filter press 150, the first magnesium hydroxide filter cake and the first chlorine are obtained Change sodium filtrate.It may be also containing residual magnesium ion, magnesium hydroxide in the first sodium chloride filtrate.The first sodium chloride filtrate It can be all filtrates obtained when first filter press 150 carries out pressure filtration washing to first slurry, including after washing Filtrate etc..It can be connected directly or be indirectly connected between first filter press 150 and the salt dissolving device 110.Example Such as, the first sodium chloride filtrate can directly return to the salt dissolving device 110 and carry out salt dissolving processing, can also by removal of impurities with The salt dissolving device 110 is returned again to after removing residual magnesium ion and magnesium hydroxide.Removal of impurities can according to need or residual impurity Amount chooses whether to carry out or carry out in which step.For example, the first sodium chloride filtrate directly returns to the salt dissolving device 110, if impurity content is more can also to clean after salt dissolving, enters back into electrolysis unit 120 and participate in cell reaction.It is described First filter press 150 can be horizontal pressure filter etc..

The drier 160 is directly or indirectly connected with first filter press 150.The first magnesium hydroxide filter cake It can convey, can also be conveyed through feeding spiral conveyer through belt feeder, to be transported to the drier 160.The drier 160 can be flash distillation dryer etc..Drying source can use natural gas.The magnesium hydroxide products obtained after drying can be with It is packed into automatic packaging machine.After magnesium hydrate powder after drying may also pass through calcining furnace calcining, to be aoxidized Magnesium products.Therefore, it can be also used for production magnesium oxide product according to the technique and scheme of the present invention.The high temperature tail that calcination process generates Gas can return to the drier 160, to use as dry heat source, can be realized the recycling of the energy, in this way to reach To the purpose of energy-saving and emission-reduction.

It according to the technique and scheme of the present invention, can be full by combining chloralkali process with magnesium hydroxide production technology The comprehensive utilization of resource is realized while sufficient chlorine industry and magnesium hydroxide production requirement.In the entire system by sodium compound Recycling, cyclic balance and the effective use of sodium resource may be implemented.In this cyclic process, sodium be it is nonexpendable, Therefore it in addition to normal loss may need additionally to add sodium chloride into the salt dissolving device 110, does not need to add chlorination again Sodium or sodium hydroxide.And other than product magnesium hydroxide or magnesia generate, also generated without additional waste residue, thus Realize the clean manufacturing of entire technical process and the zero-emission of waste residue.

Fig. 2 shows a kind of a kind of embodiment signals for the system for cleaning loop production magnesium hydroxide according to the present invention Figure.

As shown in Fig. 2, can also include size-mixing tank 210 between first filter press 150 and the drier 160, with First filter press 150 is connected, and for receiving the first magnesium hydroxide filter cake and sizing mixing to it, generates the second slurry Material；Second filter press 220 is connected between the size-mixing tank 210 and the drier 160, for receiving second slurry And pressure filtration washing is carried out to it, obtain the second magnesium hydroxide filter cake, the second sodium chloride filtrate and Washing of Filter Cake water；The tune Stock tank 210 is also used to receive the Washing of Filter Cake water, to size mixing to the first magnesium hydroxide filter cake；The drier 160, for receiving the second magnesium hydroxide filter cake and it being dried, obtain magnesium hydroxide products.

The size-mixing tank 210 can be used for that the first magnesium hydroxide filter cake is sized mixing and washed, and pass through second The filters pressing and washing of filter press 220, to achieve the purpose that further cleaning to the first magnesium hydroxide filter cake, with further Improve the purity of magnesium hydroxide products.According to the present embodiment, the purity for the magnesium hydroxide products produced can achieve 99% More than.Second filter press 220 can be vertical type blotter press etc..Second filter press 220 carries out second slurry The process of pressure filtration washing can be, when filters pressing generates filter cake and the second sodium chloride filtrate, then washs to filter cake, available Washing of Filter Cake water.The Washing of Filter Cake water returns to the size-mixing tank 210 as the mother liquor or plasm scouring water uses again of sizing mixing, can be with Washing water is effectively recycled, water resource is saved.

Fig. 3 shows a kind of a kind of embodiment signal of system including water reuse (treatment processing unit according to the present invention Figure.

As shown in figure 3, the second sodium chloride filtrate is the solution containing residual magnesium ion, magnesium hydroxide and sodium chloride, The system can also include water reuse (treatment processing unit 310, with second filter press 220 and 150 phase of the first filter press It even, is 10~11 for receiving the second sodium chloride filtrate and adjusting its pH value, so that in the second sodium chloride filtrate Magnesium ion forms precipitating；Include ultrafiltration ceramic membrane in the water reuse (treatment processing unit 310, separates second chlorination for intercepting Magnesium hydroxide and the precipitating in sodium filtrate, obtain sodium chloride clear solution；Further include in the water reuse (treatment processing unit 310 Reverse osmosis membrane, for separating the sodium chloride in the sodium chloride clear solution, to obtain pure water；And the pure water is returned into institute At least one of the first filter press 150, described second filter press 220 are stated, as slurry.

The second sodium chloride filtrate is due to being to carry out filters pressing generation to second slurry, wherein containing a small amount of Magnesium ion, magnesium hydroxide and sodium chloride.It is 10~11 that the solution, which is adjusted pH value, such as when 10.5, magnesium ion forms precipitating effect Fruit is obvious, especially effectively can all precipitate the magnesium ion in the second sodium chloride filtrate when pH value is 10.5. The magnesium hydrate precipitate that the magnesium hydroxide of script and adjusting pH value are formed later in the second sodium chloride filtrate can pass through Ultrafiltration ceramic membrane intercepts separation, and can be with recycling and reusing, such as forms product after treatment.The reverse osmosis membrane separation institute It states the sodium chloride that sodium chloride clear solution obtains and can be recycled to the salt dissolving device 110 and utilized again.The pure water is Salt content is less than the water of 30ppm, can be used as slurry recycling.According to the present embodiment, following for washing water is realized Ring uses, and water-saving result is significant.

Fig. 4 shows a kind of a kind of embodiment schematic diagram of system including tail salt treatment device according to the present invention.

As shown in figure 4, the first sodium chloride filtrate is the sodium chloride solution containing residual magnesium ion, magnesium hydroxide, institute The system of stating can also include tail salt treatment device 410, be connected to first filter press 150 and the salt dissolving device 110 it Between, for receiving the first sodium chloride filtrate and sequentially adding hydrochloric acid, sodium hydroxide, coagulant, flocculant thereto, to certainly So the supernatant of magnesium hydroxide wadding body and sodium chloride-containing is obtained after sedimentation；It further include fiber mistake in the tail salt treatment device 410 Filter is filtered for the supernatant to the sodium chloride-containing, to filter suspended matter, obtains third sodium chloride filtrate；It is described Salt dissolving device 110 is also used to receive the third sodium chloride filtrate and carries out salt dissolving, to be deployed into the saturated sodium chloride solution.

The tail salt treatment device 410 in present embodiment is one to clean to the first sodium chloride filtrate For example, system of the invention can be not limited to this removal of impurities mode in the case where there is removal of impurities to need.First chlorination Sodium filtrate is due to being the solution reacted in magnesium hydroxide synthesizer 140, and sodium chloride is major solute, wherein may It has remaining magnesium ion and wears the magnesium hydroxide etc. of filter.The first sodium chloride filtrate can be collected by collecting tank, then defeated It send to the tail salt treatment device 410.By the way that hydrochloric acid is added into the first sodium chloride filtrate, make the magnesium hydroxide in solution All dissolutions, it is unfavorable to remove ultra-small grain size magnesium hydroxide crystal that may be present, ultra-small grain size magnesium hydroxide crystal in solution In later separation；Add sodium hydroxide, the magnesium ion in solution can be made to be completely formed precipitating, and by be added coagulant and Flocculant has the magnesium hydrate precipitate to be formed to facilitate separation in the form of wadding body, is separated after natural subsidence, institute The supernatant of sodium chloride-containing is stated by the suspended matter in the fabric filter again filtering solution, after processing qualified chlorination Sodium solution is the third sodium chloride filtrate.The third sodium chloride filtrate returns to the salt dissolving device 110 and carries out salt dissolving, real The circulation comprehensive for having showed resource utilizes.

Fig. 5 shows a kind of a kind of embodiment schematic diagram of system including vaporising device according to the present invention.

As shown in figure 5, can also include vaporising device 510, with the electrolysis unit 120 and 110 phase of salt dissolving device Even, for unsaturation sodium chloride solution described in receiving portion and it is evaporated, then makes it into the salt dissolving device 110, to be deployed into the saturated sodium chloride solution.

The unsaturation sodium chloride solution can fully enter the salt analysis apparatus 130 and saltout, can also be according to life It produces and part is needed to enter the evaporation that the vaporising device 510 carries out excessive moisture, then enter back into the salt dissolving device 110 and carry out Salt dissolving.For example, if the unsaturation sodium chloride solution according to production needs, cannot or not need to fully enter described saltout Device 130 is saltoutd, then the extra part unsaturated sodium chloride solution can be evaporated and recycle, so that its It can recycle in system and utilize again, avoid the wasting of resources and the generation of waste residue.

Fig. 6 shows a kind of method flow diagram for cleaning loop production magnesium hydroxide according to the present invention.

As shown in fig. 6, a kind of method for cleaning loop production magnesium hydroxide is provided, including, chlor-alkali production step S1: pass through Salt dissolving device produces saturated sodium chloride solution；The saturated sodium chloride solution enters electrolysis unit and is electrolysed, and generates hydroxide Sodium solution, chlorine, hydrogen and unsaturated sodium chloride solution；Salting-out step S2: magnesium chloride hexahydrate crystal and the unsaturated chlorine Change sodium solution and enter salt analysis apparatus, precipitated sodium chloride crystal generates magnesium chloride solution；The sodium chloride crystal returns to the salt dissolving Device carries out salt dissolving, to be deployed into the saturated sodium chloride solution；Magnesium hydroxide production stage S3: the magnesium chloride solution and institute It states sodium hydroxide solution and enters magnesium hydroxide synthesizer, reaction generates the first slurry；First slurry enters the first filters pressing Machine is filtered washing, generates the first magnesium hydroxide filter cake and the first sodium chloride filtrate；The first sodium chloride filtrate returns to institute It states salt dissolving device and carries out salt dissolving, to be deployed into the saturated sodium chloride solution；After the first magnesium hydroxide filter cake is dried, Obtain magnesium hydroxide products.

A kind of embodiment according to the present invention, the magnesium hydroxide production stage S3 further include first hydroxide Magnesium filter cake passes through following steps before being dried: the first magnesium hydroxide filter cake enters size-mixing tank and sizes mixing, and generates second Slurry；Second slurry enters the second filter press and carries out pressure filtration washing, obtains the second magnesium hydroxide filter cake, the filter of the second sodium chloride Liquid and Washing of Filter Cake water；The Washing of Filter Cake water returns to the size-mixing tank and sizes mixing to the first magnesium hydroxide filter cake； The second magnesium hydroxide filter cake after drying, obtains magnesium hydroxide products.

A kind of embodiment according to the present invention, the second sodium chloride filtrate are containing residual magnesium ion, magnesium hydroxide With the solution of sodium chloride, the method also includes water reuse (treatment processing step S4: the pH value for adjusting the second sodium chloride filtrate is 10~11, so that the magnesium ion in the second sodium chloride filtrate forms precipitating；It intercepts and separates in the second sodium chloride filtrate Magnesium hydroxide and the precipitating, obtain sodium chloride clear solution；The sodium chloride clear solution is by reverse osmosis by sodium chloride Separation, obtains pure water；The pure water enters at least one of first filter press, second filter press, as washing Use water.

A kind of embodiment according to the present invention, the first sodium chloride filtrate are containing residual magnesium ion, magnesium hydroxide Sodium chloride solution, the method also includes the first sodium chloride filtrate passes through tail salt treatment before returning to the salt dissolving device Step S5: the tail salt treatment step S5 includes sequentially adding hydrochloric acid in Xiang Suoshu the first sodium chloride filtrate, sodium hydroxide, mixing Solidifying agent, flocculant, and the supernatant of magnesium hydroxide wadding body and sodium chloride-containing is obtained after natural subsidence；The supernatant of the sodium chloride-containing Liquid obtains third sodium chloride filtrate by the filtering of fabric filter to filter suspended matter；The third sodium chloride filtrate returns The salt dissolving device carries out salt dissolving, to be deployed into the saturated sodium chloride solution.

A kind of embodiment according to the present invention further includes that the part unsaturated sodium chloride solution is laggard through pervaporation Enter the salt dissolving device, to be deployed into the saturated sodium chloride solution.

Method of the invention hereinbefore has been combined system and is described in detail and explains, will no longer go to live in the household of one's in-laws on getting married here It states.

Fig. 7 shows the grain size distribution of sodium chloride crystal according to the present invention.Wherein, (a) in Fig. 7 shows chlorination The grading curve figure of sodium crystal；(b) in Fig. 7 shows the transmission electron microscope picture of sodium chloride crystal.

As shown in fig. 7, according to the technique and scheme of the present invention, the sodium chloride saltoutd in the salt analysis apparatus 130 Crystal particle diameter is evenly distributed, and can satisfy electrolysis and requires.

Fig. 8 shows the grain size distribution of magnesium hydroxide products according to the present invention.Wherein, (a) in Fig. 8 shows hydrogen The grading curve figure of magnesium oxide product；(b) in Fig. 8 shows the transmission electron microscope picture of magnesium hydroxide products.

As shown in figure 8, according to the technique and scheme of the present invention, the particle diameter distribution of the magnesium hydroxide products of preparation is uniform, product It is high-quality；And granularity is averagely about 50 μm, granularity can significantly reduce greatly filtering and energy consumption for drying.

Advantages of the present invention at least that:

1) according to the technique and scheme of the present invention, by combining chloralkali process with magnesium hydroxide production technology, Neng Gou Meet the comprehensive utilization that resource is realized while chlorine industry and magnesium hydroxide production requirement；

2) according to the technique and scheme of the present invention, the recycling by sodium compound in the entire system realizes sodium money The cyclic balance in source and effective use realize the clean manufacturing of entire technical process and the zero-emission of waste residue；And it forms The cleaning loop production mode of " resource-production-product-consumption-waste renewable resources-production-product-consumption "；

3) according to the technique and scheme of the present invention, by water reuse (treatment processing scheme, the recycling of washing water is realized, it is water-saving Significant effect.

It should be noted that the above-mentioned embodiments illustrate rather than limit the invention, and this Field technical staff can be designed alternative embodiment without departing from the scope of the appended claims.In claim In, any reference symbol between parentheses should not be configured to limitations on claims.