CN109020021A - It is a kind of sea desalination and strong brine comprehensively utilize energy saving technique - Google Patents

Abstract

A kind of sea desalination and strong brine comprehensively utilize energy saving technique, take sodium chloride-containing, magnesium sulfate, potassium chloride, sodium bromide, magnesium chloride extra large salt water be raw material, carry out extra large desalination, obtain fresh water and strong brine；By the strong brine using air blowout method production bromine and debrominate strong brine；The debrominate strong brine nanofiltration separation is obtained into monovalence compound strong brine and bivalent compound strong brine, monovalence strong brine high temperature evaporation is obtained into sodium chloride and salt-making mother liquor, the salt-making mother liquor low-temperature evaporation is obtained into potassium chloride and potassium mother liquor processed, the potassium Recycling Mother Solution processed is extremely mixed with debrominate strong brine and carries out nanofiltration, divalent strong brine high temperature evaporation is obtained into magnesium sulfate monohydrate and mother liquid of magnesium processed, which is concentrated by evaporation cooling and obtains magnesium chloride product.The present invention has process flow reasonable, and heat utilization rate is high, and product quality is high, and production cost and energy consumption are greatly lowered, realize the characteristics of strong brine zero-emission, is adapted to extensive extra large desalination.

Description

It is a kind of sea desalination and strong brine comprehensively utilize energy saving technique

Technical field

The invention belongs to technical field of inorganic chemical industry, especially a kind of extra large desalination and strong brine comprehensively utilize energy saving workSkill.

Background technique

Extra large desalination and strong brine comprehensive utilization, i.e., extract fresh water, chemical element, chemicals and deep processing from seawaterDeng.It is known using the seawater of the components such as saliferous, magnesium sulfate, extra large desalination potassium chloride, bromine, magnesium chloride as raw material for producing fresh waterAnd strong brine, adding halogen method produce salt, magnesium sulfate, potassium chloride, bromine and magnesium chloride technique, are a kind of synthesis of sewater chemistry resourceUsing technique, however that there are process flows is long for the technique, and heat energy utilization is unreasonable, and steam consumption is very high, and the production cost is very high, noThe problem of adapting to extensive extra large desalination.Therefore, the above method produces salt, magnesium sulfate, potassium chloride, bromine and magnesium chlorideProcess economy and adaptability are all poor.

Summary of the invention

The object of the present invention is to provide a kind of extra large desalinations and strong brine to comprehensively utilize energy saving technique, utilizes membrane technologyFresh water, monovalence and bivalent compound are separated, separation monovalence and bivalent compound is evaporated by reasonable process routes, is conducive to dropLow investment, energy consumption and cost, the problem of can solve less economical prior art and adaptability.

To achieve the above object, the present invention takes following technical scheme:

It is a kind of sea desalination and strong brine comprehensively utilize energy saving technique, which is characterized in that it includes the following steps:

A. take sodium chloride-containing, magnesium sulfate, potassium chloride, sodium bromide, magnesium chloride extra large salt water be raw material, using thermal distillation method orHyperfiltration or electroosmose process carry out extra large desalination, and desalination temperature is 20-130 DEG C, obtain fresh water and strong brine；

B. by the strong brine using air blowout method production bromine and debrominate strong brine；

C. the debrominate strong brine nanofiltration separation is obtained into monovalence compound strong brine (containing a small amount of bivalent compound) and twoValence compound strong brine (contains a small amount of monovalence compound), and nanofiltration temperature is 20--30 DEG C；

D. monovalence compound strong brine high temperature evaporation is obtained into sodium chloride and salt-making mother liquor, evaporating temperature is 100-140 DEG C；

E. the salt-making mother liquor low-temperature evaporation is obtained into potassium chloride and potassium mother liquor processed (containing part bivalent compound), evaporation temperatureDegree is 20-70 DEG C；

F. by the potassium Recycling Mother Solution processed to step C, nanofiltration, mixing temperature 20-30 are mixed and carried out with debrominate strong brine℃；

G. bivalent compound strong brine high temperature evaporation is obtained into magnesium sulfate monohydrate and mother liquid of magnesium processed, evaporating temperature 70-140℃；

H. the mother liquid of magnesium processed is concentrated by evaporation cooling and obtains magnesium chloride product, evaporating temperature is 20-130 DEG C.

Further, each component content in the raw material are as follows: NaCl 15-40g/l, KCl 0.3-1.0g/l,NaBr0.05-0.20g/l、MgSO₄ 1.0-3.0g/l、MgCl₂ 1.5-5.0g/l。

Further, each component content in the fresh water are as follows: TDS≤500ppm, remaining be H₂O。

Further, each component content in the strong brine are as follows: NaCl 60-100g/l, KCl 1.2-2.5g/l, NaBr0.25-0.5g/l、MgSO₄ 4.0-7.5g/l、MgCl₂ 6.0-11.0g/l。

Further, each component content in the debrominate strong brine are as follows: NaCl 60-100g/l, KCl1.2-2.5g/l,MgSO₄ 4.0-7.5g/l、MgCl₂ 6.0-11.0g/l。

Further, each component content in the monovalence compound strong brine are as follows: NaCl 60-100g/l, KCl1.2-2.5g/l、MgSO₄ 0.2-0.35g/l、MgCl₂0.6-1.1g/l；Each component content in the bivalent compound strong brine are as follows:NaCl 1-2g/l、KCl 0.12-0.25g/l、MgSO₄ 40-75g/l、MgCl₂ 60-110g/l。

Further, each component content in the salt-making mother liquor are as follows: NaCl 100-250g/l, KCl150-250g/l,MgSO₄ 20-35g/l、MgCl₂ 80-140g/l。

Further, each component content in the potassium mother liquor processed are as follows: NaCl 250-280g/l, KCl150-200g/l,MgSO₄ 20-35g/l、MgCl₂ 80-140g/l。

Further, each component content in the mother liquid of magnesium processed are as follows: NaCl 4-14g/l, KCl 0.72-1.50g/l,MgSO₄ 4-14g/l、MgCl₂ 350-600g/l。

Further, the extra large desalination in the step A is using thermal distillation method or reverse osmosis or electrodialytic membranes technologyDesalinated.

Further, raw material in step A can be using sodium chloride-containing, magnesium sulfate, potassium chloride, sodium bromide, magnesium chlorideBitter or industrial wastewater are alternative materials.

The beneficial effects of the present invention are: present invention sea desalination and strong brine comprehensively utilize energy saving technique, there is techniqueProcess is reasonable, and heat utilization rate is high, and product quality is high, and production cost and energy consumption are greatly lowered, realize strong brine zero-emissionFeature is adapted to extensive extra large desalination.

Detailed description of the invention

Fig. 1 is the process flow diagram of extra large desalination and strong brine comprehensive utilization energy saving technique of the invention.

Specific embodiment

Below with reference to the preferred embodiment specific embodiment that the present invention will be described in detail.

As shown in Figure 1, the present invention provides a kind of extra large desalination and strong brine comprehensive utilization energy saving technique, it includes followingStep:

A. take sodium chloride-containing, magnesium sulfate, potassium chloride, sodium bromide, magnesium chloride extra large salt water be raw material, carry out desalt processing,Obtain fresh water and strong brine；Desalt processing is to carry out extra large desalination using thermal distillation method or hyperfiltration or electroosmose process；It is lightChanging temperature is 20-130 DEG C；

B. the strong brine is produced into bromine (Br using air blowout method₂) and debrominate strong brine；Air blowout method is normal at presentThe method for extracting bromine, is passed through chlorine to solution, the bromide ion in solution is made to be oxidized to simple substance bromine；Blast hot-air or waterSteam can distill out simple substance bromine therein；

C. the debrominate strong brine nanofiltration separation is obtained into monovalence compound strong brine (containing a small amount of bivalent compound) and twoValence compound strong brine (contains a small amount of monovalence compound), and nanofiltration temperature is 20-30 DEG C；

D. monovalence compound strong brine (containing a small amount of bivalent compound) high temperature evaporation is obtained into sodium chloride and salt-making mother liquor,100-140 DEG C of high temperature evaporation temperature；

E. the salt-making mother liquor low-temperature evaporation is obtained into potassium chloride and potassium mother liquor processed, 20-70 DEG C of low-temperature evaporation temperature；

F. the potassium mother liquor (containing part bivalent compound) processed is recycled to and mixes nanofiltration separation two with debrominate strong brineValence compound, mixing temperature are 20-30 DEG C；

G. bivalent compound strong brine high temperature evaporation is obtained into magnesium sulfate monohydrate and mother liquid of magnesium processed, high temperature evaporation temperature 70-140℃；

H. the mother liquid of magnesium processed is concentrated by evaporation cooling and obtains magnesium chloride product, evaporate 20-130 DEG C of cooling temperature.

Enumerating several specific embodiments below, the present invention is described in detail.

Embodiment 1: 900m is taken³Seawater (NaCl 30g/l, KCl 0.72g/l, NaBr 0.14g/l, MgSO₄2.15g/l、MgCl₂3.28g/l) it is raw material, 600 tons of fresh water and 300m is produced using reverse osmosis progress sea water desalination³Strong brine (NaCl90g/l、KCl 2.16g/l、NaBr 0.42g/l、MgSO₄ 6.45g/l、MgCl₂9.84g/l), 30 DEG C of reverse osmosis temperature；It will300m³Strong brine produces 0.29 ton of bromine (Br using air blowout method₂) and 300m³Debrominate strong brine (NaCl 90g/l, KCl2.16g/l、NaBr 0.015g/l、MgSO₄6.45g/l、MgCl₂9.84g/l)；By 300m³Debrominate strong brine (NaCl 90g/l、KCl 2.16g/l、NaBr0.015g/l、MgSO₄ 6.45g/l、MgCl₂9.84g/l) and 3.49m³Potassium mother liquor (NaCl processed250g/l、KCl 193g/l、MgSO₄ 26.1g/l、MgCl₂303.49m after 87.2g/l) mixing³Mixed liquor nanofiltration separation obtains278.7m³Monovalence compound strong brine (NaCl 100g/l, KCl 4.7g/l, MgSO₄ 0.3g/l、MgCl₂1.0g/l) and24.79m³Bivalent compound strong brine (NaCl 1.2g/l, KCl 0.12g/l, MgSO₄ 78.05g/l、MgCl₂ 119.08g/L), 25 DEG C of nanofiltration temperature；By 278.7m³Monovalence compound strong brine (NaCl 100g/l, KCl 4.7g/l, MgSO₄ 0.3g/l、MgCl₂1.0g/l) high temperature evaporation obtains 26.96 tons of sodium chloride and 3.82m³Salt-making mother liquor (NaCl 228g/l, KCl 346g/l,MgSO₄ 23.8g/l、MgCl₂79.7g/l), 125 DEG C of evaporating temperature；By 3.82m³Salt-making mother liquor low-temperature evaporation obtains 0.63 tonPotassium chloride and 3.49m³Potassium mother liquor (NaCl 250g/l, KCl 193g/l, MgSO processed₄ 26.1g/l、MgCl₂87.2g/l)；It will3.49m³Potassium mother liquor (NaCl 250g/l, KCl 193g/l, MgSO processed₄ 26.1g/l、MgCl₂It 87.2g/l) is recycled to and debrominateNanofiltration separation bivalent compound is gone in strong brine mixing；By 24.79m³Bivalent compound strong brine (NaCl 1.2g/l, KCl0.12g/l、MgSO₄ 78.05g/l、MgCl₂119.08g/l) high temperature evaporation obtains 2.05 tons of magnesium sulfate monohydrates and 6.87m³SystemMother liquid of magnesium (NaCl 4.33g/l, KCl 0.43g/l, MgSO₄ 23.4g/l、MgCl₂430g/l), 100 DEG C of evaporating temperature；It will6.87m³Mother liquid of magnesium processed is concentrated by evaporation cooling and obtains 6.91 tons of magnesium chlorides (containing MgCl₂42.75%).

Embodiment 2: 900m is taken³Seawater (NaCl 30g/l, KCl 0.72g/l, NaBr 0.14g/l, MgSO₄2.15g/l、MgCl₂3.28g/l) it is raw material, sea water desalination is carried out using thermal distillation and produces 600 tons of fresh water and 300m³Strong brine (NaCl90g/l、KCl 2.16g/l、NaBr 0.42g/l、MgSO₄ 6.45g/l、MgCl₂9.84g/l), 80 DEG C of thermal distillation temperature；It will300m³Strong brine produces 0.29 ton of bromine (Br using air blowout method₂) and 300m³Debrominate strong brine (NaCl 90g/l, KCl2.16g/l、NaBr 0.015g/l、MgSO₄6.45g/l、MgCl₂9.84g/l)；By 300m³Debrominate strong brine (NaCl 90g/l、KCl 2.16g/l、NaBr0.015g/l、MgSO₄ 6.45g/l、MgCl₂9.84g/l) and 3.49m³Potassium mother liquor (NaCl processed250g/l、KCl 193g/l、MgSO₄ 26.1g/l、MgCl₂303.49m after 87.2g/l) mixing³Mixed liquor nanofiltration separation obtains278.7m³Monovalence compound strong brine (NaCl 100g/l, KCl 4.7g/l, MgSO₄ 0.3g/l、MgCl₂1.0g/l) and24.79m³Bivalent compound strong brine (NaCl 1.2g/l, KCl 0.12g/l, MgSO₄ 78.05g/l、MgCl₂ 119.08g/L), 25 DEG C of nanofiltration temperature；By 278.7m³Monovalence compound strong brine (NaCl 100g/l, KCl 4.7g/l, MgSO₄ 0.3g/l、MgCl₂1.0g/l) high temperature evaporation obtains 26.96 tons of sodium chloride and 3.82m³Salt-making mother liquor (NaCl 228g/l, KCl 346g/l,MgSO₄ 23.8g/l、MgCl₂79.7g/l), 125 DEG C of evaporating temperature；By 3.82m³Salt-making mother liquor low-temperature evaporation obtains 0.63 tonPotassium chloride and 3.49m³Potassium mother liquor (NaCl 250g/l, KCl 193g/l, MgSO processed₄ 26.1g/l、MgCl₂87.2g/l)；It will3.49m³Potassium mother liquor (NaCl 250g/l, KCl 193g/l, MgSO processed₄ 26.1g/l、MgCl₂It 87.2g/l) is recycled to and debrominateNanofiltration separation bivalent compound is gone in strong brine mixing；By 24.79m³Bivalent compound strong brine (NaCl 1.2g/l, KCl0.12g/l、MgSO₄ 78.05g/l、MgCl₂119.08g/l) high temperature evaporation obtains 2.05 tons of magnesium sulfate monohydrates and 6.87m³SystemMother liquid of magnesium (NaCl 4.33g/l, KCl 0.43g/l, MgSO₄ 23.4g/l、MgCl₂430g/l), 100 DEG C of evaporating temperature；It will6.87m³Mother liquid of magnesium processed is concentrated by evaporation cooling and obtains 6.91 tons of magnesium chlorides (containing MgCl₂42.75%).

Embodiment 3: 900m is taken³Seawater (NaCl 30g/l, KCl 0.72g/l, NaBr 0.14g/l, MgSO₄2.15g/l、MgCl₂3.28g/l) it is raw material, sea water desalination is carried out using electrodialysis and produces 600 tons of fresh water and 300m³Strong brine (NaCl90g/l、KCl 2.16g/l、NaBr 0.42g/l、MgSO₄ 6.45g/l、MgCl₂9.84g/l), 25 DEG C of electric osmose eutectoid temperature；It will300m³Strong brine produces 0.29 ton of bromine (Br using air blowout method₂) and 300m³Debrominate strong brine (NaCl 90g/l, KCl2.16g/l、NaBr 0.015g/l、MgSO₄6.45g/l、MgCl₂9.84g/l)；By 300m³Debrominate strong brine (NaCl 90g/l、KCl 2.16g/l、NaBr0.015g/l、MgSO₄ 6.45g/l、MgCl₂9.84g/l) and 3.49m³Potassium mother liquor (NaCl processed250g/l、KCl 193g/l、MgSO₄ 26.1g/l、MgCl₂303.49m after 87.2g/l) mixing³Mixed liquor nanofiltration separation obtains278.7m³Monovalence compound strong brine (NaCl 100g/l, KCl 4.7g/l, MgSO₄ 0.3g/l、MgCl₂1.0g/l) and24.79m³Bivalent compound strong brine (NaCl 1.2g/l, KCl 0.12g/l, MgSO₄ 78.05g/l、MgCl₂ 119.08g/L), 25 DEG C of nanofiltration temperature；By 278.7m³Monovalence compound strong brine (NaCl 100g/l, KCl 4.7g/l, MgSO₄ 0.3g/l、MgCl₂1.0g/l) high temperature evaporation obtains 26.96 tons of sodium chloride and 3.82m³Salt-making mother liquor (NaCl 228g/l, KCl 346g/l,MgSO₄ 23.8g/l、MgCl₂79.7g/l), 125 DEG C of evaporating temperature；By 3.82m³Salt-making mother liquor low-temperature evaporation obtains 0.63 tonPotassium chloride and 3.49m³Potassium mother liquor (NaCl 250g/l, KCl 193g/l, MgSO processed₄ 26.1g/l、MgCl₂87.2g/l)；It will3.49m³Potassium mother liquor (NaCl 250g/l, KCl 193g/l, MgSO processed₄ 26.1g/l、MgCl₂It 87.2g/l) is recycled to and debrominateNanofiltration separation bivalent compound is gone in strong brine mixing；By 24.79m³Bivalent compound strong brine (NaCl 1.2g/l, KCl0.12g/l、MgSO₄ 78.05g/l、MgCl₂119.08g/l) high temperature evaporation obtains 2.05 tons of magnesium sulfate monohydrates and 6.87m³SystemMother liquid of magnesium (NaCl 4.33g/l, KCl 0.43g/l, MgSO₄ 23.4g/l、MgCl₂430g/l), 100 DEG C of evaporating temperature；It will6.87m³Mother liquid of magnesium processed is concentrated by evaporation cooling and obtains 6.91 tons of magnesium chlorides (containing MgCl₂42.75%).

Embodiment 4: 900m is taken³Bitter (NaCl 3g/l, KCl 0.072g/l, NaBr 0.014g/l,MgSO₄0.215g/l、MgCl₂0.328g/l) be raw material, using reverse osmosis progresss brackish water desalination produce 870 tons of fresh water with30m³Strong brine (NaCl 90g/l, KCl 2.16g/l, NaBr 0.42g/l, MgSO₄ 6.45g/l、MgCl₂9.84g/l), instead30 DEG C of temperature of infiltration；By 30m³Strong brine produces 0.029 ton of bromine (Br using air blowout method₂) and 30m³Debrominate strong brine (NaCl90g/l、KCl 2.16g/l、NaBr 0.015g/l、MgSO₄6.45g/l、MgCl₂9.84g/l)；By 30m³Debrominate strong brine(NaCl 90g/l、KCl 2.16g/l、NaBr0.015g/l、MgSO₄ 6.45g/l、MgCl₂9.84g/l) and 0.349m³Potassium processedMother liquor (NaCl 250g/l, KCl 193g/l, MgSO₄ 26.1g/l、MgCl₂30.349m after 87.2g/l) mixing³Mixed liquor is receivedFilter isolated 27.87m³Monovalence compound strong brine (NaCl 100g/l, KCl 4.7g/l, MgSO₄ 0.3g/l、MgCl₂1.0g/l) and 2.479m³Bivalent compound strong brine (NaCl 1.2g/l, KCl 0.12g/l, MgSO₄ 78.05g/l、MgCl₂119.08g/l), 25 DEG C of nanofiltration temperature；By 27.87m³Monovalence compound strong brine (NaCl 100g/l, KCl 4.7g/l、MgSO₄ 0.3g/l、MgCl₂1.0g/l) high temperature evaporation obtains 2.696 tons of sodium chloride and 0.382m³Salt-making mother liquor (NaCl228g/l、KCl 346g/l、MgSO₄ 23.8g/l、MgCl₂79.7g/l), 125 DEG C of evaporating temperature；By 0.382m³Salt-making mother liquorLow-temperature evaporation obtains 0.063 ton of potassium chloride and 0.349m³Potassium mother liquor (NaCl 250g/l, KCl 193g/l, MgSO processed₄ 26.1g/l、MgCl₂87.2g/l)；By 0.349m³Potassium mother liquor (NaCl 250g/l, KCl 193g/l, MgSO processed₄ 26.1g/l、MgCl₂It 87.2g/l) is recycled to and mixes nanofiltration separation bivalent compound with debrominate strong brine；By 2.479m³Bivalent compound strong brine(NaCl1.2g/l、KCl 0.12g/l、MgSO₄ 78.05g/l、MgCl₂119.08g/l) high temperature evaporation obtains 0.205 ton of one waterMagnesium sulfate and 0.687m³Mother liquid of magnesium (NaCl 4.33g/l, KCl 0.43g/l, MgSO processed₄ 23.4g/l、MgCl₂430g/l),100 DEG C of evaporating temperature；By 0.687m³Mother liquid of magnesium processed is concentrated by evaporation cooling and obtains 0.691 ton of magnesium chloride (containing MgCl₂42.75%).

Embodiment 5: 900m is taken³Bitter (NaCl 3g/l, KCl 0.072g/l, NaBr 0.014g/l,MgSO₄0.215g/l、MgCl₂0.328g/l) be raw material, using thermal distillation carry out brackish water desalination produce 870 tons of fresh water and30m³Strong brine (NaCl 90g/l, KCl 2.16g/l, NaBr 0.42g/l, MgSO₄ 6.45g/l、MgCl₂9.84g/l), hot80 DEG C of vapo(u)rizing temperature；By 30m³Strong brine produces 0.029 ton of bromine (Br using air blowout method₂) and 30m³Debrominate strong brine (NaCl90g/l、KCl 2.16g/l、NaBr 0.015g/l、MgSO₄6.45g/l、MgCl₂9.84g/l)；By 30m³Debrominate strong brine(NaCl 90g/l、KCl 2.16g/l、NaBr0.015g/l、MgSO₄ 6.45g/l、MgCl₂9.84g/l) and 0.349m³Potassium processedMother liquor (NaCl 250g/l, KCl 193g/l, MgSO₄ 26.1g/l、MgCl₂30.349m after 87.2g/l) mixing³Mixed liquor is receivedFilter isolated 27.87m³Monovalence compound strong brine (NaCl 100g/l, KCl 4.7g/l, MgSO₄ 0.3g/l、MgCl₂1.0g/l) and 2.479m³Bivalent compound strong brine (NaCl 1.2g/l, KCl 0.12g/l, MgSO₄ 78.05g/l、MgCl₂119.08g/l), 25 DEG C of nanofiltration temperature；By 27.87m³Monovalence compound strong brine (NaCl 100g/l, KCl 4.7g/l、MgSO₄ 0.3g/l、MgCl₂1.0g/l) high temperature evaporation obtains 2.696 tons of sodium chloride and 0.382m³Salt-making mother liquor (NaCl228g/l、KCl 346g/l、MgSO₄ 23.8g/l、MgCl₂79.7g/l), 125 DEG C of evaporating temperature；By 0.382m³Salt-making mother liquorLow-temperature evaporation obtains 0.063 ton of potassium chloride and 0.349m³Potassium mother liquor (NaCl 250g/l, KCl 193g/l, MgSO processed₄ 26.1g/l、MgCl₂87.2g/l)；By 0.349m³Potassium mother liquor (NaCl 250g/l, KCl 193g/l, MgSO processed₄ 26.1g/l、MgCl₂It 87.2g/l) is recycled to and mixes nanofiltration separation bivalent compound with debrominate strong brine；By 2.479m³Bivalent compound strong brine(NaCl1.2g/l、KCl 0.12g/l、MgSO₄ 78.05g/l、MgCl₂119.08g/l) high temperature evaporation obtains 0.205 ton of one waterMagnesium sulfate and 0.687m³Mother liquid of magnesium (NaCl 4.33g/l, KCl 0.43g/l, MgSO processed₄ 23.4g/l、MgCl₂430g/l),100 DEG C of evaporating temperature；By 0.687m³Mother liquid of magnesium processed is concentrated by evaporation cooling and obtains 0.691 ton of magnesium chloride (containing MgCl₂42.75%).

Embodiment 6: 900m is taken³Bitter (NaCl 3g/l, KCl 0.072g/l, NaBr 0.014g/l,MgSO₄0.215g/l、MgCl₂0.328g/l) be raw material, using electrodialysis carry out brackish water desalination produce 870 tons of fresh water and30m³Strong brine (NaCl 90g/l, KCl 2.16g/l, NaBr 0.42g/l, MgSO₄ 6.45g/l、MgCl₂9.84g/l), electric25 DEG C of dialysis temperature；By 30m³Strong brine produces 0.029 ton of bromine (Br using air blowout method₂) and 30m³Debrominate strong brine (NaCl90g/l、KCl 2.16g/l、NaBr 0.015g/l、MgSO₄6.45g/l、MgCl₂9.84g/l)；By 30m³Debrominate strong brine(NaCl 90g/l、KCl 2.16g/l、NaBr0.015g/l、MgSO₄ 6.45g/l、MgCl₂9.84g/l) and 0.349m³Potassium processedMother liquor (NaCl 250g/l, KCl 193g/l, MgSO₄ 26.1g/l、MgCl₂30.349m after 87.2g/l) mixing³Mixed liquor is receivedFilter isolated 27.87m³Monovalence compound strong brine (NaCl 100g/l, KCl 4.7g/l, MgSO₄ 0.3g/l、MgCl₂1.0g/l) and 2.479m³Bivalent compound strong brine (NaCl 1.2g/l, KCl 0.12g/l, MgSO₄ 78.05g/l、MgCl₂119.08g/l), 25 DEG C of nanofiltration temperature；By 27.87m³Monovalence compound strong brine (NaCl 100g/l, KCl 4.7g/l、MgSO₄ 0.3g/l、MgCl₂1.0g/l) high temperature evaporation obtains 2.696 tons of sodium chloride and 0.382m³Salt-making mother liquor (NaCl228g/l、KCl 346g/l、MgSO₄ 23.8g/l、MgCl₂79.7g/l), 125 DEG C of evaporating temperature；By 0.382m³Salt-making mother liquorLow-temperature evaporation obtains 0.063 ton of potassium chloride and 0.349m³Potassium mother liquor (NaCl 250g/l, KCl 193g/l, MgSO processed₄ 26.1g/l、MgCl₂87.2g/l)；By 0.349m³Potassium mother liquor (NaCl 250g/l, KCl 193g/l, MgSO processed₄ 26.1g/l、MgCl₂It 87.2g/l) is recycled to and mixes nanofiltration separation bivalent compound with debrominate strong brine；By 2.479m³Bivalent compound strong brine(NaCl1.2g/l、KCl 0.12g/l、MgSO₄ 78.05g/l、MgCl₂119.08g/l) high temperature evaporation obtains 0.205 ton of one waterMagnesium sulfate and 0.687m³Mother liquid of magnesium (NaCl 4.33g/l, KCl 0.43g/l, MgSO processed₄ 23.4g/l、MgCl₂430g/l),100 DEG C of evaporating temperature；By 0.687m³Mother liquid of magnesium processed is concentrated by evaporation cooling and obtains 0.691 ton of magnesium chloride (containing MgCl₂42.75%).

The present invention has process flow reasonable, and heat utilization rate is high, and product quality is high, and production cost and energy consumption significantly dropIt is low, realize the characteristics of strong brine zero-emission, be adapted to extensive extra large desalination.

The above described is only a preferred embodiment of the present invention, not making in any form to structure of the inventionLimitation.Any simple modification, equivalent change and modification to the above embodiments according to the technical essence of the invention,In the range of still falling within technical solution of the present invention.

Claims (10)

1. a kind of sea desalination and strong brine comprehensively utilize energy saving technique, which is characterized in that it includes the following steps:

A. take sodium chloride-containing, magnesium sulfate, potassium chloride, sodium bromide, magnesium chloride extra large salt water be raw material, carry out extra large desalination, it is lightChanging temperature is 20-130 DEG C, obtains fresh water and strong brine；

B. by the strong brine using air blowout method production bromine and debrominate strong brine；

C. the debrominate strong brine nanofiltration separation is obtained into monovalence compound strong brine and bivalent compound strong brine, nanofiltration temperature is20--30℃；

D. monovalence strong brine high temperature evaporation is obtained into sodium chloride and salt-making mother liquor, evaporating temperature is 100-140 DEG C；

E. the salt-making mother liquor low-temperature evaporation is obtained into potassium chloride and potassium mother liquor processed, evaporating temperature is 20-70 DEG C；

F. by the potassium Recycling Mother Solution processed to step C, nanofiltration is mixed and carried out with debrominate strong brine, and mixing temperature is 20-30 DEG C；

G. divalent strong brine high temperature evaporation is obtained into magnesium sulfate monohydrate and mother liquid of magnesium processed, evaporating temperature is 70-140 DEG C；

H. the mother liquid of magnesium processed is concentrated by evaporation cooling and obtains magnesium chloride product, evaporating temperature is 20-130 DEG C.

2. sea desalination according to claim 1 and strong brine comprehensively utilize energy saving technique, which is characterized in that the originalEach component content in material are as follows: NaCl 15-40g/l, KCl 0.3-1.0g/l, NaBr 0.05-0.20g/l, MgSO₄ 1.0-3.0g/l、MgCl₂ 1.5-5.0g/l。

3. sea desalination according to claim 1 and strong brine comprehensively utilize energy saving technique, which is characterized in that described lightEach component content in water are as follows: TDS≤500ppm, remaining be H₂O。

4. sea desalination according to claim 1 and strong brine comprehensively utilize energy saving technique, which is characterized in that described denseEach component content in salt water are as follows: NaCl 60-100g/l, KCl 1.2-2.5g/l, NaBr 0.25-0.5g/l, MgSO₄ 4.0-7.5g/l、MgCl₂ 6.0-11.0g/l。

5. sea desalination according to claim 1 and strong brine comprehensively utilize energy saving technique, which is characterized in that described de-Each component content in bromine strong brine are as follows: NaCl 60-100g/l, KCl 1.2-2.5g/l, MgSO₄ 4.0-7.5g/l、MgCl₂6.0-11.0g/l。

6. sea desalination according to claim 1 and strong brine comprehensively utilize energy saving technique, which is characterized in that described oneEach component content in valence compound strong brine are as follows: NaCl 60-100g/l, KCl 1.2-2.5g/l, MgSO₄ 0.2-0.35g/l、MgCl₂0.6-1.1g/l；Each component content in the bivalent compound strong brine are as follows: NaCl 1-2g/l, KCl 0.12-0.25g/l、MgSO₄ 40-75g/l、MgCl₂ 60-110g/l。

7. sea desalination according to claim 1 and strong brine comprehensively utilize energy saving technique, which is characterized in that the systemEach component content in salt mother liquor are as follows: NaCl 100-250g/l, KCl 150-250g/l, MgSO₄ 20-35g/l、MgCl₂ 80-140g/l。

8. sea desalination according to claim 1 and strong brine comprehensively utilize energy saving technique, which is characterized in that the systemEach component content in potassium mother liquor are as follows: NaCl 250-280g/l, KCl 150-200g/l, MgSO₄ 20-35g/l、MgCl₂ 80-140g/l。

9. sea desalination according to claim 1 and strong brine comprehensively utilize energy saving technique, which is characterized in that the systemEach component content in mother liquid of magnesium are as follows: NaCl 4-14g/l, KCl 0.72-1.50g/l, MgSO₄ 4-14g/l、MgCl₂ 350-600g/l。

10. sea desalination according to claim 1 and strong brine comprehensively utilize energy saving technique, which is characterized in that describedExtra large desalination in step A is desalinated using thermal distillation method or reverse osmosis or electrodialytic membranes technology.