CN113149035A - Method for treating waste sodium chloride salt - Google Patents
Method for treating waste sodium chloride salt Download PDFInfo
- Publication number
- CN113149035A CN113149035A CN202110424968.7A CN202110424968A CN113149035A CN 113149035 A CN113149035 A CN 113149035A CN 202110424968 A CN202110424968 A CN 202110424968A CN 113149035 A CN113149035 A CN 113149035A
- Authority
- CN
- China
- Prior art keywords
- salt
- solid
- treatment
- sodium chloride
- solution
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 title claims abstract description 133
- 239000002699 waste material Substances 0.000 title claims abstract description 93
- 238000000034 method Methods 0.000 title claims abstract description 82
- 150000003839 salts Chemical class 0.000 claims abstract description 270
- 239000000243 solution Substances 0.000 claims abstract description 67
- 238000005406 washing Methods 0.000 claims abstract description 66
- 239000011780 sodium chloride Substances 0.000 claims abstract description 65
- 239000007788 liquid Substances 0.000 claims abstract description 55
- 238000001179 sorption measurement Methods 0.000 claims abstract description 51
- 238000000926 separation method Methods 0.000 claims abstract description 42
- 239000012528 membrane Substances 0.000 claims abstract description 37
- 238000005868 electrolysis reaction Methods 0.000 claims abstract description 30
- 238000002791 soaking Methods 0.000 claims abstract description 29
- 238000001704 evaporation Methods 0.000 claims abstract description 22
- 239000012047 saturated solution Substances 0.000 claims abstract description 17
- 238000004064 recycling Methods 0.000 claims abstract description 15
- 238000001914 filtration Methods 0.000 claims abstract description 14
- 238000002156 mixing Methods 0.000 claims abstract description 11
- 239000007787 solid Substances 0.000 claims abstract description 9
- 239000004576 sand Substances 0.000 claims abstract description 8
- 239000010865 sewage Substances 0.000 claims abstract description 6
- 239000006210 lotion Substances 0.000 claims abstract description 4
- 238000000197 pyrolysis Methods 0.000 claims description 88
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 79
- 238000002386 leaching Methods 0.000 claims description 50
- 239000011347 resin Substances 0.000 claims description 43
- 229920005989 resin Polymers 0.000 claims description 43
- 150000002500 ions Chemical class 0.000 claims description 21
- 229910052799 carbon Inorganic materials 0.000 claims description 19
- 239000002994 raw material Substances 0.000 claims description 18
- 230000008020 evaporation Effects 0.000 claims description 16
- 239000003795 chemical substances by application Substances 0.000 claims description 13
- 238000002425 crystallisation Methods 0.000 claims description 13
- 230000008025 crystallization Effects 0.000 claims description 13
- MHAJPDPJQMAIIY-UHFFFAOYSA-N Hydrogen peroxide Chemical compound OO MHAJPDPJQMAIIY-UHFFFAOYSA-N 0.000 claims description 12
- 229920006395 saturated elastomer Polymers 0.000 claims description 12
- 238000007654 immersion Methods 0.000 claims description 11
- 239000005416 organic matter Substances 0.000 claims description 11
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 claims description 10
- 238000007254 oxidation reaction Methods 0.000 claims description 10
- 239000012452 mother liquor Substances 0.000 claims description 9
- 239000012266 salt solution Substances 0.000 claims description 7
- 238000004140 cleaning Methods 0.000 claims description 6
- 239000012459 cleaning agent Substances 0.000 claims description 6
- 239000000203 mixture Substances 0.000 claims description 6
- ZCYVEMRRCGMTRW-UHFFFAOYSA-N 7553-56-2 Chemical compound [I] ZCYVEMRRCGMTRW-UHFFFAOYSA-N 0.000 claims description 5
- 229910052740 iodine Inorganic materials 0.000 claims description 5
- 239000011630 iodine Substances 0.000 claims description 5
- 230000003647 oxidation Effects 0.000 claims description 5
- 239000004408 titanium dioxide Substances 0.000 claims description 5
- 230000014759 maintenance of location Effects 0.000 claims description 4
- -1 carbon lipid Chemical class 0.000 claims description 3
- 239000010413 mother solution Substances 0.000 claims description 3
- 230000001568 sexual effect Effects 0.000 claims description 3
- 238000005189 flocculation Methods 0.000 claims description 2
- 230000016615 flocculation Effects 0.000 claims description 2
- 230000008595 infiltration Effects 0.000 claims description 2
- 238000001764 infiltration Methods 0.000 claims description 2
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 abstract description 33
- 235000011121 sodium hydroxide Nutrition 0.000 abstract description 11
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 40
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 description 12
- 230000007935 neutral effect Effects 0.000 description 10
- 239000003480 eluent Substances 0.000 description 9
- 239000012535 impurity Substances 0.000 description 9
- 238000000108 ultra-filtration Methods 0.000 description 9
- 239000010408 film Substances 0.000 description 8
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 description 6
- 238000003763 carbonization Methods 0.000 description 5
- 238000001035 drying Methods 0.000 description 5
- 238000005516 engineering process Methods 0.000 description 5
- 230000008929 regeneration Effects 0.000 description 5
- 238000011069 regeneration method Methods 0.000 description 5
- 239000003513 alkali Substances 0.000 description 4
- 238000005119 centrifugation Methods 0.000 description 4
- 230000000694 effects Effects 0.000 description 4
- 239000000126 substance Substances 0.000 description 4
- 230000002378 acidificating effect Effects 0.000 description 3
- 238000006243 chemical reaction Methods 0.000 description 3
- 239000004519 grease Substances 0.000 description 3
- 239000010410 layer Substances 0.000 description 3
- 239000003960 organic solvent Substances 0.000 description 3
- 239000002344 surface layer Substances 0.000 description 3
- 239000008399 tap water Substances 0.000 description 3
- 235000020679 tap water Nutrition 0.000 description 3
- 239000010409 thin film Substances 0.000 description 3
- 239000002351 wastewater Substances 0.000 description 3
- NWZSZGALRFJKBT-KNIFDHDWSA-N (2s)-2,6-diaminohexanoic acid;(2s)-2-hydroxybutanedioic acid Chemical compound OC(=O)[C@@H](O)CC(O)=O.NCCCC[C@H](N)C(O)=O NWZSZGALRFJKBT-KNIFDHDWSA-N 0.000 description 2
- 235000013162 Cocos nucifera Nutrition 0.000 description 2
- 244000060011 Cocos nucifera Species 0.000 description 2
- KFZMGEQAYNKOFK-UHFFFAOYSA-N Isopropanol Chemical compound CC(C)O KFZMGEQAYNKOFK-UHFFFAOYSA-N 0.000 description 2
- PFLUPZGCTVGDLV-UHFFFAOYSA-N acetone azine Chemical compound CC(C)=NN=C(C)C PFLUPZGCTVGDLV-UHFFFAOYSA-N 0.000 description 2
- 239000002253 acid Substances 0.000 description 2
- 230000004913 activation Effects 0.000 description 2
- 239000010405 anode material Substances 0.000 description 2
- 238000001514 detection method Methods 0.000 description 2
- 238000004090 dissolution Methods 0.000 description 2
- 238000005265 energy consumption Methods 0.000 description 2
- 230000007613 environmental effect Effects 0.000 description 2
- 238000000605 extraction Methods 0.000 description 2
- 230000005484 gravity Effects 0.000 description 2
- IKDUDTNKRLTJSI-UHFFFAOYSA-N hydrazine monohydrate Substances O.NN IKDUDTNKRLTJSI-UHFFFAOYSA-N 0.000 description 2
- 239000002440 industrial waste Substances 0.000 description 2
- 239000012071 phase Substances 0.000 description 2
- 239000004094 surface-active agent Substances 0.000 description 2
- 230000005526 G1 to G0 transition Effects 0.000 description 1
- DBMJMQXJHONAFJ-UHFFFAOYSA-M Sodium laurylsulphate Chemical compound [Na+].CCCCCCCCCCCCOS([O-])(=O)=O DBMJMQXJHONAFJ-UHFFFAOYSA-M 0.000 description 1
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 1
- 150000001298 alcohols Chemical class 0.000 description 1
- 150000001491 aromatic compounds Chemical class 0.000 description 1
- 230000033558 biomineral tissue development Effects 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 238000009835 boiling Methods 0.000 description 1
- 239000012267 brine Substances 0.000 description 1
- 239000006227 byproduct Substances 0.000 description 1
- 238000001354 calcination Methods 0.000 description 1
- 238000012824 chemical production Methods 0.000 description 1
- 239000003245 coal Substances 0.000 description 1
- 238000005336 cracking Methods 0.000 description 1
- 239000012043 crude product Substances 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 238000000354 decomposition reaction Methods 0.000 description 1
- 239000003599 detergent Substances 0.000 description 1
- 230000018109 developmental process Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 208000028659 discharge Diseases 0.000 description 1
- 238000004821 distillation Methods 0.000 description 1
- 239000003814 drug Substances 0.000 description 1
- 239000007772 electrode material Substances 0.000 description 1
- 238000010336 energy treatment Methods 0.000 description 1
- 150000002148 esters Chemical class 0.000 description 1
- 239000000706 filtrate Substances 0.000 description 1
- 229910002804 graphite Inorganic materials 0.000 description 1
- 239000010439 graphite Substances 0.000 description 1
- 239000002920 hazardous waste Substances 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 150000002391 heterocyclic compounds Chemical class 0.000 description 1
- 230000002209 hydrophobic effect Effects 0.000 description 1
- 238000005286 illumination Methods 0.000 description 1
- 239000000543 intermediate Substances 0.000 description 1
- CJTCBBYSPFAVFL-UHFFFAOYSA-N iridium ruthenium Chemical compound [Ru].[Ir] CJTCBBYSPFAVFL-UHFFFAOYSA-N 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000000155 melt Substances 0.000 description 1
- 238000001471 micro-filtration Methods 0.000 description 1
- 230000003472 neutralizing effect Effects 0.000 description 1
- 238000009856 non-ferrous metallurgy Methods 0.000 description 1
- 239000002957 persistent organic pollutant Substances 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 238000002203 pretreatment Methods 0.000 description 1
- KJAQRHMKLVGSCG-UHFFFAOYSA-N propan-2-ylhydrazine Chemical compound CC(C)NN KJAQRHMKLVGSCG-UHFFFAOYSA-N 0.000 description 1
- 238000000746 purification Methods 0.000 description 1
- 230000035484 reaction time Effects 0.000 description 1
- 238000007670 refining Methods 0.000 description 1
- HPALAKNZSZLMCH-UHFFFAOYSA-M sodium;chloride;hydrate Chemical compound O.[Na+].[Cl-] HPALAKNZSZLMCH-UHFFFAOYSA-M 0.000 description 1
- 238000011895 specific detection Methods 0.000 description 1
- 238000003860 storage Methods 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 238000003786 synthesis reaction Methods 0.000 description 1
- 229910052719 titanium Inorganic materials 0.000 description 1
- 239000010936 titanium Substances 0.000 description 1
- 238000009736 wetting Methods 0.000 description 1
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01D—COMPOUNDS OF ALKALI METALS, i.e. LITHIUM, SODIUM, POTASSIUM, RUBIDIUM, CAESIUM, OR FRANCIUM
- C01D3/00—Halides of sodium, potassium or alkali metals in general
- C01D3/14—Purification
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01D—COMPOUNDS OF ALKALI METALS, i.e. LITHIUM, SODIUM, POTASSIUM, RUBIDIUM, CAESIUM, OR FRANCIUM
- C01D3/00—Halides of sodium, potassium or alkali metals in general
- C01D3/04—Chlorides
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F9/00—Multistage treatment of water, waste water or sewage
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/02—Treatment of water, waste water, or sewage by heating
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/02—Treatment of water, waste water, or sewage by heating
- C02F1/04—Treatment of water, waste water, or sewage by heating by distillation or evaporation
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/28—Treatment of water, waste water, or sewage by sorption
- C02F1/283—Treatment of water, waste water, or sewage by sorption using coal, charred products, or inorganic mixtures containing them
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/30—Treatment of water, waste water, or sewage by irradiation
- C02F1/32—Treatment of water, waste water, or sewage by irradiation with ultraviolet light
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/46—Treatment of water, waste water, or sewage by electrochemical methods
- C02F1/461—Treatment of water, waste water, or sewage by electrochemical methods by electrolysis
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/52—Treatment of water, waste water, or sewage by flocculation or precipitation of suspended impurities
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/72—Treatment of water, waste water, or sewage by oxidation
- C02F1/722—Oxidation by peroxides
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/72—Treatment of water, waste water, or sewage by oxidation
- C02F1/725—Treatment of water, waste water, or sewage by oxidation by catalytic oxidation
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Inorganic Chemistry (AREA)
- Life Sciences & Earth Sciences (AREA)
- Hydrology & Water Resources (AREA)
- Environmental & Geological Engineering (AREA)
- Water Supply & Treatment (AREA)
- Processing Of Solid Wastes (AREA)
- Water Treatment By Electricity Or Magnetism (AREA)
Abstract
The invention relates to a method for treating sodium chloride waste salt generated by an industrial sewage treatment process, which comprises the steps of soaking and washing the sodium chloride waste salt to obtain solid-liquid coexisting salt; standing the solid-liquid coexisting state salt, and performing solid-liquid separation; performing a soaking and washing step on solid salt obtained after solid-liquid separation in a circulating manner, standing, performing solid-liquid separation for one to multiple times to obtain crude purified salt, detecting a salt-containing concentrated solution obtained after solid-liquid separation, adding the salt-containing concentrated solution into a lotion again when the salt-containing solution is an unsaturated solution and the content of organic matters is lower than the standard, circulating until a nearly saturated solution or a saturated solution is obtained, recycling the salt-containing concentrated solution to the original process when the salt-containing concentrated solution is a nearly saturated solution or a saturated solution and the content of organic matters is lower than the standard, and directly evaporating to dryness and pyrolyzing to obtain the primary purified salt when the content of organic matters is equal to or higher than the standard; dissolving the coarse purified salt, and performing carbon-fat adsorption to obtain primary purified salt; mixing and dissolving the purified salt obtained twice, removing sand and filtering to obtain purified salt treatment liquid; the purified salt treatment solution is reused for the ion membrane electrolysis process. The invention has low process cost, and the purified salt formed after treatment can meet the purity requirement of the ionic membrane caustic soda.
Description
Technical Field
The invention relates to the field of environmental protection engineering and technology, in particular to a method for treating waste sodium chloride salt.
Background
The byproduct sodium chloride waste salt is produced in chemical production of medicament synthesis, chemical intermediates and the like in China, and the annual output exceeds 500 ten thousand tons. The waste sodium chloride salts contain esters, alcohols, aromatic and heterocyclic compounds, and because the waste salts are difficult to treat and high in treatment cost, the waste salts are generally treated by adopting a centralized temporary storage mode of enterprise and enterprise warehouses at present, and serious environmental hidden dangers exist.
The sodium chloride waste salt contains abundant recyclable substances. The recycling of the waste salt is a way for reducing the pollution of the waste salt to the environment and realizing circular economy, the ionic membrane electrolysis process for recycling the sodium chloride waste salt is the best way for recycling the sodium chloride waste salt at present, and the key of recycling the sodium chloride waste salt is to remove organic matters and other impurities in the waste salt.
The prior art of Chinese patent publication No. CN110642270A discloses a method for refining and treating industrial waste salt, which adopts a mixed pretreatment method of the industrial waste salt and a salt washing agent to obtain pretreated salt and filtrate, melts the salt and utilizes oxidation, adsorption and evaporative crystallization to obtain refined crystal salt, thereby solving the problem of recycling of partial waste salt, but the content of organic matters in the treated salt is still high, and the reuse of the ionic membrane electrolysis process cannot be realized.
The prior art of Chinese patent publication No. CN110201975A discloses a method for treating industrial hazardous waste salt by utilizing drying, primary carbonization and deep carbonization, wherein the primary carbonization and the deep carbonization are respectively at 400-500 ℃ and 500-700 ℃, the carbonization time is 2-4 h, the treated salt can be used for preparing alkali by ion membrane electrolysis, but the treatment technology has the advantages of long calcination time, high energy consumption and high treatment cost, and is relatively suitable for treating waste salt with extremely high organic content, and the waste salt with relatively low or moderate organic content is used, so that the treatment and operation cost is very high.
In fact, the high-temperature heat treatment technology has a remarkable effect on the treatment of the waste salt, but the treatment and operation cost is high, and even the recycling value is possibly lower than the treatment cost. Therefore, an efficient and low-cost waste salt treatment and reuse integrated process is urgently needed to be developed, so that the waste salt organic matters are efficiently removed, the waste salt is maximally recycled, and the near zero emission of the waste salt is realized.
Disclosure of Invention
The invention aims to solve one or more of the problems, and provides a method for treating waste sodium chloride salt, wherein the purified salt formed after treatment can meet the purity requirement of ionic membrane caustic soda, and is applied to the ionic membrane caustic soda process. The whole process can reduce the treatment cost for enterprises while realizing the reutilization of the waste salt, and has industrial application prospect.
According to one aspect of the invention, the method for treating the waste sodium chloride salt comprises the following steps: the sodium chloride waste salt is soaked and washed by using the lotion, and the soaking and washing degree is that only the solid-liquid surface of the sodium chloride waste salt and the lotion is kept to be soaked, so that a film is formed on the surface of the sodium chloride waste salt, and the sodium chloride waste salt is in a solid-liquid coexisting state; standing the solid-liquid coexisting state salt for a period of time, and then carrying out solid-liquid separation; carrying out immersion washing, standing and solid-liquid separation on solid salt obtained after solid-liquid separation for one to multiple times to obtain coarse purified salt; dissolving the coarse purified salt, and performing carbon-fat adsorption treatment to obtain primary purified salt; detecting the content of organic matters in the salt-containing concentrated solution obtained after solid-liquid separation, adding the salt-containing concentrated solution into the washing agent when the content of the organic matters is lower than the standard, and circularly performing the steps of leaching or dripping, standing and solid-liquid separation on the waste sodium chloride until the salt-containing concentrated solution with the content of the organic matters higher than the standard is obtained; sequentially evaporating and pyrolyzing salt-containing concentrated solution with the organic matter content higher than the standard to obtain primary purified salt; and uniformly removing sand and filtering the purified salt obtained after adsorption treatment and segmented pyrolysis to obtain the purified salt.
Wherein the soaking and washing mode is leaching or dripping washing, and the ratio of the used washing agent to the sodium chloride waste salt is 1:1-1: 10.
Wherein the temperature of the soaking and washing is 10-90 ℃, and the time of each soaking and washing is 0.25-2 h.
Wherein, the detection of the concentrated solution containing salt is to determine whether the organic matter content standard reaches saturation.
The segmented pyrolysis step sequentially comprises low-temperature pyrolysis and high-temperature pyrolysis, wherein the temperature of the low-temperature pyrolysis is 300-400 ℃, and the pyrolysis time is 0.25-2 h; the high-temperature pyrolysis temperature is 400-600 ℃, and the pyrolysis time is 0.25-2 h.
Wherein the carbon lipid adsorption treatment comprises sexual carbon adsorption, resin adsorption or combined adsorption of activated carbon and resin, wherein the iodine value of an activated carbon column is 800-1000, and the retention time of the crude purified salt solution passing through the activated carbon column is 10-30 min; in the sand removal and filtration step, the molecular weight cut-off is 9000-12000 daltons; in the step of solid-liquid separation, the standing time is 0.25-2h, the separation mode is centrifugal separation, the centrifugal rotation speed is 800-2000 r, and the centrifugal time is 0.2-0.4 h.
Wherein, the solid salt is circulated to carry out the steps of infiltration washing, standing and solid-liquid separation, and the circulation frequency is 2-6 times.
Wherein, the treatment method also comprises a deep treatment step after the solid-liquid separation step and before the carbon fat adsorption treatment: and (3) carrying out electrolytic treatment on the crude purified salt or adopting advanced oxidation treatment of hydrogen peroxide, ultraviolet rays and titanium dioxide for co-oxidation.
According to another aspect of the present invention, there is provided a method for treating and recycling sodium chloride waste salt generated in an industrial sewage treatment process, comprising the steps of: the method comprises the following steps of (1) carrying out immersion cleaning on sodium chloride waste salt by using a cleaning agent, wherein the immersion cleaning degree is that only the solid-liquid surfaces of the sodium chloride waste salt and the cleaning agent are kept to be immersed, so that a film is formed on the surface of the sodium chloride waste salt, and the sodium chloride waste salt is in a solid-liquid coexisting state; standing the solid-liquid coexisting state salt for a period of time, and then carrying out solid-liquid separation; carrying out a soaking and washing step, standing and a solid-liquid separation step one or more times on solid salt obtained after solid-liquid separation to obtain coarse purified salt, detecting salt-containing concentrated solution obtained after solid-liquid separation, adding the salt-containing concentrated solution into a washing agent again when the salt-containing solution is an unsaturated solution and the content of organic matters is lower than the content of organic matters in mother liquor generated along with waste salt after crystallization treatment after an industrial sewage treatment process, circularly carrying out a leaching or dripping washing step, a standing step and a solid-liquid separation step on sodium chloride waste salt until the salt-containing concentrated solution which is nearly saturated and has the content of organic matters close to or higher than the mother liquor is obtained, recycling the salt-containing concentrated solution to the mechanical steam recompression process or the multi-effect evaporation process of the factory when the salt-containing solution is a nearly saturated solution or a saturated solution and has the content of organic matters lower than the mother liquor, directly evaporating the crude product to dryness for pyrolysis treatment to obtain primary purified salt; dissolving the coarse purified salt, and performing carbon-fat adsorption treatment to obtain primary purified salt again; mixing the purified salt obtained after adsorption treatment and distillation pyrolysis for dissolution, sand removal and filtration to obtain purified salt treatment solution; the obtained purified salt treatment solution is used as the composition of the ionic membrane electrolysis anode raw material for recycling the ionic membrane electrolysis process.
Wherein the soaking and washing mode is leaching or dripping washing, and the ratio of the used washing agent to the sodium chloride waste salt is 1:1-1: 10.
Wherein the temperature of the soaking and washing is 10-90 ℃, and the time of each soaking and washing is 0.25-2 h.
Wherein the salt content in the sodium chloride waste salt to be treated is 60-98%.
The soaking and washing agent is saline water, pure water, tap water, and proportioned saline water and saturated saline water, and the salt concentration is 0-330 mg/L.
Wherein, the wetting detergent is added with a surfactant sodium dodecyl sulfate, or is mixed with other organic solvents, methanol, acetone and the like for washing, the boiling point of the organic solvent is not higher than 100 ℃, and the mixing ratio is 1-100%.
Wherein the leaching mode is gravity flow, in the gravity flow, the waste salt is a stationary phase, water or saline water is a mobile phase for leaching or drip washing, only the liquid-solid interface is kept to be soaked, the solid-liquid ratio is 10: 1-1:1, and the washing and standing time is 0.25-2 h.
Wherein the number of times of circulating and repeated washing of the solid salt is 2-6, the washing and standing time is 0.25-2h, and the preferred number of times is 3-4.
The soaking and washing temperature can be 10-90 ℃, namely the water temperature can be 10-90 ℃, the salt temperature is preferably 10-150 ℃, the water temperature and the salt temperature can be different, and the water temperature is preferably 10-30 ℃.
Wherein, the separation mode after the soaking and washing is centrifugal separation.
Wherein, the solid-liquid separation mode is centrifugation, the rotation speed of the centrifugation is 500-5000 revolutions, and the centrifugation time is 0.2-1 h.
Wherein the concentration of the solution after the dissolution of the crude purification salt is 100-330 mg/L.
Wherein the treatment method also comprises a deep treatment step after the solid-liquid separation step and before the carbon fat adsorption treatment: the crude purified salt is subjected to electrolytic treatment or electric flocculation treatment or advanced oxidation treatment by adopting hydrogen peroxide, ultraviolet rays and titanium dioxide for co-oxidation.
Wherein the carbon and fat adsorption comprises activated carbon adsorption, resin adsorption or activated carbon and resin combined adsorption.
Wherein, the step of filtering and removing impurities can adopt ultrafiltration treatment.
Wherein, the filtration and impurity removal can be carried out by microfiltration, conventional filtration, ultrafiltration and the like, and ultrafiltration is preferred.
The salt water obtained by filtering and impurity removal can be mixed with industrial salt and salt after pyrolysis treatment to be used as the raw material of the ion membrane electrolysis anode, wherein the salt content in the purified salt treatment solution accounts for 10-100% of the salt content of the total raw material of the ion membrane electrolysis anode. The concentration of the brine of the raw material of the ionic membrane electrolysis anode is 290-320 mg/L.
Wherein the number of the multi-stage pyrolysis stages is 2-4, and 2 stages are preferred.
Wherein the temperature of the front section of the multi-section pyrolysis is 300-400 ℃, the front section can be divided into 1-2 sections, and the pyrolysis time is 0.25-2 hours, preferably 0.5-1 hour.
Wherein the temperature of the rear section of the multi-section pyrolysis is 300-550 ℃, the temperature of the front section can be divided into 1-2 sections, and the pyrolysis time is 0.25-2 hours, preferably 0.5-1 hour.
Wherein the carbon lipid adsorption treatment comprises sexual carbon adsorption, resin adsorption or combined adsorption of activated carbon and resin, wherein the iodine value of an activated carbon column is 800-1000, and the retention time of the crude purified salt solution passing through the activated carbon column is 10-30 min;
wherein, in the sand removal and filtration step, the cut-off molecular weight is 9000-12000 daltons.
The sodium chloride waste salt is waste salt generated by a mechanical steam recompression process, wherein the TOC content is 1000-5000 mg/kg, and the salt content is 60-98%.
Wherein the pyrolysis apparatus is a rotary kiln.
Wherein, the section of the rotary furnace of the pyrolysis equipment can be added with a crushing process such as a reamer and the like.
Compared with the prior art, the invention has the following technical advantages:
1. the invention combines the soaking and washing on the basis of the pyrolysis process, and the purified salt after washing is dissolved and then is subjected to an advanced treatment process, thereby realizing the pyrolysis reduction treatment and having better industrial application prospect for reducing the treatment cost of enterprises.
2. The content of organic matters in the sodium chloride waste salt treated by the technology is lower than 30mg/kg or the voltage of an ion membrane electrolytic cell is not increased, the treated salt is filtered to remove impurities, and the concentrated salt is directly used as a raw material for preparing the ion membrane caustic soda or is mixed with industrial salt and salt after pyrolysis treatment and then is used as a raw material for preparing the ion membrane caustic soda after being mixed according to a proportion, so that the sodium chloride waste salt is recycled.
3. The invention adopts the film for soaking and washing, and compared with the conventional salt washing method, the invention reduces the using amount of the eluting agent, reduces the treatment cost and simultaneously reduces the loss rate of salt; water or saline water is used as the eluting agent, so that organic matters and salt are conveniently separated, and the obtained eluting concentrated solution is easier to treat.
4. The invention can realize zero discharge treatment of eluting concentrated solution, which mainly comprises 3 treatment modes, when the organic matters in the eluting solution are not saturated, the eluting solution is recycled as the eluting solution, and the thin film soaking salt washing is continuously carried out, so that the using amount of the eluting solution is saved or the eluting solution returns to the MVR evaporation section of the original process MVR of a factory, and the continuous circulation is realized, thereby realizing the concentration and enrichment of the organic matters; when the organic matter content in the leaching concentrated solution is higher than the organic matter concentration of the crystallization mother liquor, the leaching concentrated solution and the pyrolysis mixed mother liquor can directly enter a pyrolysis evaporation section and then enter pyrolysis for treatment.
5. The pyrolysis adopts multi-section pyrolysis, low-temperature pyrolysis is adopted for evaporation of water and light organic matters (acetone, isopropyl hydrazine, isopropanol and the like) and conversion of the organic matters, high-temperature pyrolysis is adopted for mineralization of the organic matters, thorough separation of the organic matters from salts is realized, and energy consumption and treatment cost are reduced.
6. The technology of the invention can realize the complete removal of the waste salt and organic matter in the MVR process, reduce the content of the organic matter to less than or equal to 10mg/L, realize the regular decrement of the whole MVR process system, reduce the operation load of the MVR process and reduce the operation cost of the MVR process.
Drawings
FIG. 1 is a flow chart of a method for treating waste sodium chloride salt according to an embodiment of the present invention;
FIGS. 2 and 3 are graphs showing the effect of organic matter treatment in a method for treating waste sodium chloride salt according to an embodiment of the present invention;
FIG. 4 is a diagram showing the effect of organic matter treatment in the staged pyrolysis step of the method for treating waste sodium chloride salt according to the embodiment of the present invention.
DETAILED DESCRIPTION OF EMBODIMENT (S) OF INVENTION
Exemplary embodiments of the present disclosure will be described in more detail below. While exemplary embodiments of the present disclosure have been shown in the specification, it should be understood that the present disclosure may be embodied in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.
The technical solution of the present invention will be explained in further detail by the form of specific embodiments.
Example 1
High-salt-content wastewater generated in a hydrazine hydrate preparation process by a ketazine method in a chemical enterprise is subjected to MVR (mechanical vapor recompression) process and crystallization to obtain sodium chloride waste salt, and the TOC (total organic carbon) of the sodium chloride waste salt is detected to be 1000 mg/kg. The treatment and recycling process is shown in figure 1.
The method of the invention is that the film is soaked and washed firstly, and the film soaking and washing is to wash the waste salt by using a proper amount of water, so that the surface layer of the salt forms a film layer. The water or saline water is used as eluent, and the water or saline water for film immersion and washing can be pure water, tap water, proportioned saline water, saturated saline water and the like, and the salt concentration is 310 mg/L. After single leaching, the leaching temperature is 25 ℃, the washing time is 0.25h, the leaching frequency is 2 times, and the TOC is reduced to 65 mg/kg.
And (4) performing salt and leaching underflow separation on the soaked and washed salt through centrifugation for 0.15h to obtain washed salt and leaching concentrated solution. And (3) enabling the washed salt to enter an advanced treatment unit, wherein the advanced treatment unit mainly selected is carbon grease adsorption, and the carbon grease adsorption comprises activated carbon adsorption, resin adsorption or activated carbon resin combined adsorption. The activated carbon is granular activated carbon, and the resin is macroporous resin. After the adsorption treatment of the carbon and the grease, the TOC can reach 33mg/kg, namely the TOC of a nearly saturated solution prepared by the salt is lower than 10 mg/L. After the activated carbon is adsorbed and saturated, performing regeneration treatment by a rotary furnace; after the macroporous resin is saturated by adsorption, the macroporous resin can be regenerated by alkali washing and methanol.
The salt solution after advanced treatment is further purified by ultrafiltration treatment, and the obtained salt can be directly used or used in a mixing ratio with industrial salt and salt after pyrolysis treatment as an ion membrane electrolysis anode raw material (TOC is less than or equal to 10mg/L), wherein the salt content in the purified salt treatment solution accounts for 80% of the salt content in the total ion membrane electrolysis anode raw material. The organic matter treatment effect is shown in fig. 2 and 3.
And (3) feeding the leaching concentrated solution into a pyrolysis pre-evaporation section to obtain sodium chloride waste salt, wherein the TOC is 2200mg/kg through detection. And (3) performing secondary pyrolysis by adopting pyrolysis, wherein the temperature of the front-stage pyrolysis is 400 ℃, air is introduced, the pyrolysis time is 0.5h, and the TOC of the obtained salt is 200 mg/kg. The pyrolysis temperature of the later stage is 550 ℃, air is introduced, the pyrolysis time is 0.5h, and the TOC of the obtained salt is 15 mg/kg.
Preparing the salt subjected to pyrolysis treatment into a nearly saturated solution, performing ultrafiltration to remove impurities and refine, wherein the salt subjected to pyrolysis can be directly used after filtration and impurity removal or used in a mixing ratio with industrial salt and washed salt as an ion membrane electrolysis anode raw material (TOC is less than or equal to 10mg/L), wherein the total salt content of the purified salt treatment solution accounts for 100% of the salt content of the total ion membrane electrolysis anode raw material.
Example 2
As shown in fig. 1, in a process for preparing hydrazine hydrate by a ketazine method in a chemical enterprise, high-salt-content wastewater is generated, firstly sodium chloride waste salt is obtained by MVR or multi-effect evaporation process and continuous crystallization, and TOC is 4000 mg/kg.
The method of the invention firstly adopts leaching and soaking membrane washing, and the main process is to use a proper amount of water as a mobile phase to leach and wash the waste salt, so that the surface layer of the salt forms a thin film layer. And (3) adopting water and a subsequent filtered salt solution with the TOC content lower than 280g/L as a eluting agent, eluting and soaking the membrane to elute salt, wherein the salt water ratio is set to be 10: 1-1: 1.
And during rinsing, rinsing is repeated once every other standing time, and the rinsing and standing time is 1 h. The repeated leaching times are 3 times, and the leaching temperature is set to be 30 ℃. Meanwhile, methanol is added in the leaching treatment, and the mixture is washed in a ratio of 0.1-100%.
And after the leaching treatment, performing centrifugal separation at the rotating speed of 1600 revolutions for 0.3h to obtain near-dry salt (coarse purified salt) and a salt-containing concentrated solution. The TOC of the crude purified salt was 20 mg/kg.
The content of organic matters in the leached salt is further reduced by an advanced treatment unit, and the selected advanced treatment unit is activated carbon + resin adsorption. Selecting coconut shell activated carbon with an iodine value of 900 from the activated carbon, adopting 2-3 carbon columns to operate in series, enabling the prepared solution to pass through the activated carbon columns, and keeping the solution for 30 min. And adding resin for adsorption after an activated carbon adsorption unit, wherein the resin is macroporous resin, and the adsorption is carried out by adopting macroporous resin XAD-200G, and the TOC is 10 mg/kg.
After the activated carbon is adsorbed and saturated, regeneration treatment can be carried out by a rotary furnace, wherein the temperature of a drying conversion section is 100 ℃, the temperature of a pyrolysis section is 600 ℃, and the temperature of a steam activation section is 850-1000 ℃. (ii) a After the macroporous resin is saturated by adsorption, the macroporous resin can be regenerated by acid washing, alkali washing, alkaline saline and the like. And (3) washing the acidic resin with 1-5 times of the volume of the resin of HCl solution (concentration of 2-4%) for 30-90 minutes, then slowly leaching for 30-60 minutes at the same flow rate of pure water, and then quickly leaching until the pH of effluent is neutral at 6-7 by increasing the flow rate by 5-7 times per hour. The alkaline resin method is the same as the above, 3-6% NaOH is used as regeneration liquid, and leaching is carried out until the pH of effluent is neutral at 7-8. Preparing alkaline saline water with 6-8% of NaCl and 1-4% of NaOH by using neutral resin), washing the neutral resin with 2.5 times of resin by volume for 60-80 minutes, then soaking for 2-4 hours, and leaching until the pH of effluent is neutral and 6-7.
The salt solution after advanced treatment is further purified by ultrafiltration treatment with cut-off molecular weight of 10000 Dalton, the obtained salt can be directly used or used in a mixing ratio with industrial salt and salt after pyrolysis treatment as an ion membrane electrolysis anode raw material (TOC is less than or equal to 33mg/kg), and the ratio of the treated salt to other salts is as follows: the treated salt (mass) accounts for 10% of the salt content (mass) of the total ion membrane electrolysis anode material.
The leaching waste liquid is generated in the prior leaching process and is subjected to zero-emission treatment, and the leaching waste liquid mainly comprises 3 treatment modes, wherein one treatment mode comprises the following steps: when the salinity or organic matters in the eluent do not reach saturation, the eluent is recycled as the eluent, and the leaching treatment of the waste salt is continued, so that the dosage of the eluent is saved; the second step is as follows: the leacheate is unsaturated in salinity and less than 330g/L, returns to the MVR evaporation and crystallization section of the original process of a factory, and is continuously circulated to realize concentration and enrichment of organic matters; and thirdly: the salinity of the leacheate is close to saturation, the salinity is 280-330 g/L, the leacheate can directly enter a pyrolysis section, and after evaporation and crystallization, crystallized salt enters pyrolysis for treatment.
After the salinity of the leaching concentrated solution is close to saturation, the leaching concentrated solution is mixed with mother liquor produced by the original process of a factory, the mixture enters a pyrolysis section, and after evaporation and crystallization, crystallized salt enters pyrolysis for treatment. Pyrolysis treatment is adopted. The temperature in the evaporation device is controlled at 170 ℃, and the drying time is 1 d.
Waste salt obtained by mixing leaching concentrated solution and crystallization mother solution sequentially enters a low-temperature pyrolysis device and a high-temperature pyrolysis device, the temperatures are respectively controlled to be 300-400 ℃ and 400-600 ℃, air is introduced, and the pyrolysis time is 1 h.
The method is characterized in that sectional pyrolysis is adopted for treating the factory waste salt, the temperature of the front-section pyrolysis is 300-400 ℃, and the TOC of the obtained salt is 200 mg/kg. The pyrolysis temperature of the later stage is 400-600 ℃, and the TOC of the obtained salt is below 15mg/kg (the specific detection result is shown in figure 4). As can be seen from fig. 4, the pyrolysis process has mainly 4 stages, the first stage (-150 ℃) where water and light organics are mainly lost, the second and third stages are the main stages where cracking of the organics occurs, and the fourth stage is the residue decomposition stage, further removing residual organics.
In order to prevent the waste salt from thermally decomposing and caking, the pyrolysis is uniform, the pyrolysis time and the pyrolysis cost are reduced, the rotary pyrolysis is preferred, and a crushing reamer can be arranged in the rotary pyrolysis device.
The salt after pyrolysis is prepared into a nearly saturated solution, and is subjected to ultrafiltration treatment with the molecular weight cutoff of 10000 Dalton, and the solution can be directly used or used in a mixing ratio with industrial salt and washed salt as an ion membrane electrolysis anode raw material (TOC is less than or equal to 10mg/L), and the ratio of the salt after pyrolysis to other salts is as follows: the treated salt (mass) accounts for 90% of the salt content (mass) of the total ion membrane electrolysis anode material.
Taking a certain amount of salt treated by the two processes or the salt after proportioning to obtain NaCl solution, and electrolyzing by an ion membrane electrolysis device to obtain NaOH and Cl2And H2。
Example 3
And (3) carrying out back extraction on the acidic wastewater by a certain nonferrous metallurgy enterprise, neutralizing, carrying out MVR (mechanical vapor recompression) process and crystallizing to obtain sodium chloride waste salt to generate NaCl waste salt, and detecting that the TOC (total organic carbon) of the sodium chloride waste salt is 300-900 mg/kg.
Firstly, leaching treatment is adopted, wherein the leaching mode is immersion membrane washing, and the main process is to wash waste salt by using a proper amount of water so that a thin film layer is formed on the surface layer of the salt. Water or saline water is used as an eluting agent, the water or saline water for film soaking and washing can be pure water, tap water, proportioned saline water, saturated saline water and the like, and the salt concentration is 0-330 g/L. And (3) soaking the membrane with water flow to wash salt, setting the salt water ratio to be 10: 1-1:1, and setting the washing and standing time to be 0.25-2 h.
When the waste salt is leached, the leaching process is optimized, the leaching times are preferably 2-3, and the leaching temperature is 20-40 ℃. Meanwhile, organic solvents such as methanol, acetone, surfactants and the like can be added into the leaching treatment, and the mixture is washed in a ratio of 1-100%.
And after rinsing treatment, performing centrifugal separation at the rotating speed of 800-2000 revolutions for 0.2-0.4 h to obtain near-dry salt. The TOC can be lower than 30-150 mg/kg, and if the preferred leaching treatment is carried out, the TOC can be lower than 48-90 mg/kg.
After the salt is washed and is nearly saturated and dissolved, the salt is subjected to deep treatment by electrolysis, the electrode material is carbon sheets, graphite electrodes, titanium-coated ruthenium-iridium and the like, the voltage is set to be 0.2-15V, the electrolysis time is set to be 0.25-3 h, the electrolysis is finished, and the TOC of the nearly saturated salt water is reduced to 33-48 mg/kg.
After washing, salt is dissolved in a nearly saturated state, advanced oxidation treatment can be adopted, hydrogen peroxide, ultraviolet and titanium dioxide are used for co-oxidation, the concentration of the hydrogen peroxide is 0.5-5 mg/L, and the hydrogen peroxide can be added once or 4 times; the ultraviolet illumination intensity is controlled to be 1-25 mw/cm2B, carrying out the following steps of; the concentration of titanium dioxide is 0.1-1 g/L, the oxidation reaction time is 0.2-4 h, and the TOC is reduced to 15-40 mg/L after treatment.
The salt after advanced treatment can further reduce the content of organic matters through an adsorption unit, mainly removes organic pollutants with positive charges, hydrophobicity and color development, and the adsorption unit is activated carbon/resin adsorption. The activated carbon/resin adsorption comprises activated carbon adsorption, resin adsorption or activated carbon resin combined adsorption, and can be selected from three.
And preparing the leached salt into a solution, and selecting coconut shell activated carbon and coal-based activated carbon by using activated carbon as an advanced treatment unit, wherein the iodine value can be 800-1000. The prepared solution passes through an active carbon column, the retention time is 10-30 min, and 2-3 carbon columns are adopted for series operation.
And adding resin for adsorption after an activated carbon adsorption unit, wherein the resin comprises macroporous resin and the like, and adsorbing by adopting macroporous resin (such as XAD-200G and the like), so that the TOC can reach 33mg/kg (namely the TOC of a nearly saturated solution prepared by using the salt can be lower than 30 mg/kg).
After the activated carbon is adsorbed and saturated, regeneration treatment can be carried out by a rotary furnace, wherein the temperature of a drying conversion section is 100-350 ℃, the temperature of a pyrolysis section is 350-600 ℃, and the temperature of a steam activation section is 850-1000 ℃. (ii) a After the macroporous resin is saturated by adsorption, the macroporous resin can be regenerated by acid washing, alkali washing, alkaline saline and the like. And (3) washing the acidic resin with 1-5 times of the volume of the resin of HCl solution (concentration of 2-4%) for 30-90 minutes, then slowly leaching for 30-60 minutes at the same flow rate of pure water, and then quickly leaching until the pH of effluent is neutral at 6-7 by increasing the flow rate by 5-7 times per hour. The alkaline resin method is the same as the above, 3-6% NaOH is used as regeneration liquid, and leaching is carried out until the pH of effluent is neutral at 7-8. Preparing alkaline saline water with 6-8% of NaCl and 1-4% of NaOH by using neutral resin), washing the neutral resin with 2.5 times of resin by volume for 60-80 minutes, then soaking for 2-4 hours, and leaching until the pH of effluent is neutral and 6-7.
The salt solution after advanced treatment is further purified by ultrafiltration treatment with cut-off molecular weight of 10000 Dalton, the obtained salt can be directly used or used in a mixing ratio with industrial salt and salt after pyrolysis treatment as an ion membrane electrolysis anode raw material (TOC is less than or equal to 33mg/kg), and the ratio of the treated salt to other salts is 1: 10-100%.
The leaching waste liquid is generated in the prior leaching process and is subjected to zero-emission treatment, and the leaching waste liquid mainly comprises 3 treatment modes, wherein one treatment mode comprises the following steps: when the salinity or organic matters in the eluent do not reach saturation, the eluent is recycled as the eluent, and the leaching treatment of the waste salt is continued, so that the dosage of the eluent is saved; the second step is as follows: the leacheate is unsaturated in salinity and less than 330g/L, returns to the MVR evaporation and crystallization section of the original process of a factory, and is continuously circulated to realize concentration and enrichment of organic matters; and thirdly: the salinity of the leacheate is close to saturation, the salinity is 280-330 g/L, the leacheate can directly enter a pyrolysis section, and after evaporation and crystallization, crystallized salt enters pyrolysis for treatment.
The salinity of the leaching concentrated solution is close to saturation, the leaching concentrated solution can also be mixed with the mother solution produced by the original process of a factory and then enters a pyrolysis section, and after evaporation and crystallization, the crystallized salt enters pyrolysis for treatment. Pyrolysis treatment is adopted. The temperature in the evaporation device is controlled to be 120-170 ℃, and the drying time is 0.01-1 d.
The metallurgical back extraction sodium chloride waste salt contains a large amount of hydrophobic organic matters, and can be subjected to multi-stage pyrolysis treatment in the invention, wherein the front-stage pyrolysis temperature is 250-350 ℃, air is introduced, the pyrolysis time is 0.5-1 h, the rear-stage pyrolysis temperature is 350-550 ℃, air is introduced, the pyrolysis time is 0.5-1 h, and the TOC of the obtained salt can reach 33mg/kg (namely the TOC of a near-saturated solution prepared by using the salt can be lower than 33 mg/kg).
Preparing the salt subjected to pyrolysis treatment into a nearly saturated solution, performing ultrafiltration to remove impurities and refine, wherein the salt subjected to pyrolysis can be directly used after filtration and impurity removal or used in a ratio with industrial salt as an ion membrane electrolysis anode raw material (TOC is less than or equal to 10mg/L), and the salt subjected to pyrolysis treatment is matched with other salts: the pyrolysis treatment salt accounts for 10-100% of the salt content in the ionic membrane electrolysis anode raw material. .
Taking a certain amount of the treated salt or the proportioned salt to obtain NaCl solution, and electrolyzing by an ion membrane electrolysis device to obtain NaOH and Cl2And H2。
The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the appended claims.
Claims (10)
1. A method for treating sodium chloride waste salt is characterized by comprising the following steps:
the method comprises the following steps of (1) carrying out immersion cleaning on sodium chloride waste salt by using a cleaning agent, wherein the immersion cleaning degree is that only the solid-liquid surfaces of the sodium chloride waste salt and the cleaning agent are kept to be immersed, so that a film is formed on the surface of the sodium chloride waste salt, and the sodium chloride waste salt is in a solid-liquid coexisting state;
standing the solid-liquid coexisting state salt for a period of time, and then carrying out solid-liquid separation;
carrying out immersion washing, standing and solid-liquid separation on solid salt obtained after solid-liquid separation for one to multiple times to obtain coarse purified salt;
dissolving the coarse purified salt, and performing carbon-fat adsorption treatment to obtain primary purified salt;
detecting the content of organic matters in the salt-containing concentrated solution obtained after solid-liquid separation, adding the salt-containing concentrated solution into the washing agent when the content of the organic matters is lower than the standard, and circularly performing the steps of leaching or dripping, standing and solid-liquid separation on the waste sodium chloride until the salt-containing concentrated solution with the content of the organic matters higher than the standard is obtained;
sequentially evaporating and pyrolyzing salt-containing concentrated solution with the organic matter content higher than the standard to obtain primary purified salt;
and uniformly removing sand and filtering the purified salt obtained after adsorption treatment and segmented pyrolysis to obtain the purified salt.
2. The process of claim 1,
the soaking and washing mode is leaching or dripping washing, wherein the ratio of the used washing agent to the sodium chloride waste salt is 1:1-1: 10.
3. The process of claim 1,
the temperature of the soaking and washing is 10-90 ℃, and the time of each soaking and washing is 0.25-2 h.
4. A method for treating and recycling sodium chloride waste salt generated in an industrial sewage treatment process is characterized by comprising the following steps:
the method comprises the following steps of (1) carrying out immersion cleaning on sodium chloride waste salt by using a cleaning agent, wherein the immersion cleaning degree is that only the solid-liquid surfaces of the sodium chloride waste salt and the cleaning agent are kept to be immersed, so that a film is formed on the surface of the sodium chloride waste salt, and the sodium chloride waste salt is in a solid-liquid coexisting state;
standing the solid-liquid coexisting state salt for a period of time, and then carrying out solid-liquid separation;
circularly carrying out an infiltration washing step, a standing step and a solid-liquid separation step one or more times on solid salt obtained after solid-liquid separation to obtain crude purified salt, detecting salt-containing concentrated solution obtained after solid-liquid separation, adding the salt-containing concentrated solution into the lotion again when the salt-containing solution is an unsaturated solution and the content of organic matters is lower than the content of organic matters in mother liquor generated along with waste salt after crystallization treatment after the industrial sewage treatment process, circularly carrying out a leaching or dripping washing step, a standing step and a solid-liquid separation step on sodium chloride waste salt until a nearly saturated or saturated solution is obtained, recycling the salt-containing solution to the factory mechanical steam recompression process or the multi-effect evaporation process when the salt-containing solution is a nearly saturated solution or a saturated solution and the content of organic matters is lower than the mother liquor, and when the salt-containing solution is a nearly saturated solution or a saturated solution and the content of organic matters is higher than the mother liquor, directly evaporating the mixture to dryness for pyrolysis treatment;
dissolving the crude purified salt, performing carbon-fat adsorption treatment to obtain primary purified salt, and sequentially evaporating and performing segmented pyrolysis on the salt-containing concentrated solution with the organic matter content close to or higher than that of the mother solution to obtain the primary purified salt;
mixing the purified salt obtained after adsorption treatment and segmented pyrolysis, and dissolving, removing sand and filtering to obtain purified salt treatment liquid;
the obtained purified salt treatment solution is used as the composition of the ionic membrane electrolysis anode raw material for recycling the ionic membrane electrolysis process.
5. The method of claim 4, wherein the waste sodium chloride salt is treated and reused,
the immersion washing mode is drip washing or dripping washing, wherein the ratio of the used washing agent to the sodium chloride waste salt is 1:1-1: 10; the temperature of the soaking and washing is 10-90 ℃, and the time of each soaking and washing is 0.25-2 h.
6. The method of claim 4, wherein the waste sodium chloride salt is treated and reused,
the segmented pyrolysis step sequentially comprises low-temperature pyrolysis and high-temperature pyrolysis, wherein the temperature of the low-temperature pyrolysis is 300-400 ℃, and the pyrolysis time is 0.25-2 h; the high-temperature pyrolysis temperature is 400-600 ℃, and the pyrolysis time is 0.25-2 h.
7. The method of claim 4, wherein the waste sodium chloride salt is treated and reused,
the carbon lipid adsorption treatment comprises sexual carbon adsorption, resin adsorption or combined adsorption of activated carbon and resin, wherein the iodine value of an activated carbon column is 800-1000, and the retention time of the crude purified salt solution passing through the activated carbon column is 10-30 min;
in the sand removal and filtration step, the molecular weight cut-off is 9000-12000 daltons;
in the solid-liquid separation step, the standing time is 0.25-2h, the separation mode is centrifugal separation, the centrifugal rotation speed is 800-2000 revolutions, and the centrifugal time is 0.2-0.4 h;
and in the steps of soaking and washing, standing and solid-liquid separation by circulating the solid salt, the circulation frequency is 2-6 times.
8. The method for treating and recycling the waste sodium chloride salt according to claim 4, further comprising a deep treatment step after the solid-liquid separation step and before the adsorption treatment of the carbon fat, wherein the deep treatment step comprises:
the crude purified salt is subjected to electrolytic treatment or electric flocculation treatment or advanced oxidation treatment by adopting hydrogen peroxide, ultraviolet rays and titanium dioxide for co-oxidation.
9. The method of claim 4, wherein the waste sodium chloride salt is treated and reused,
the recycled ion membrane electrolysis process comprises the step of mixing and proportioning the purified salt treatment solution and industrial salt or salt after pyrolysis treatment to serve as an ion membrane electrolysis anode raw material, wherein the salt content in the purified salt treatment solution accounts for 10-100% of the salt content of the total ion membrane electrolysis anode raw material.
10. The process of claim 1,
the industrial sewage treatment process is a mechanical steam recompression process or a multi-effect evaporation process, wherein the TOC content of the sodium chloride waste salt is 1000-5000 mg/kg, and the salt content is 60-98%.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2020115860646 | 2020-12-29 | ||
| CN202011586064 | 2020-12-29 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN113149035A true CN113149035A (en) | 2021-07-23 |
| CN113149035B CN113149035B (en) | 2022-10-04 |
Family
ID=76869107
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110424968.7A Active CN113149035B (en) | 2020-12-29 | 2021-04-20 | Method for treating waste sodium chloride salt |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113149035B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116495753A (en) * | 2023-04-26 | 2023-07-28 | 中国科学院生态环境研究中心 | Method for recycling industrial waste salt through recrystallization and purification |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2008174393A (en) * | 2007-01-16 | 2008-07-31 | Jfe Engineering Kk | Method for producing salt |
| CN105883859A (en) * | 2016-06-16 | 2016-08-24 | 浙江奇彩环境科技股份有限公司 | Waste salt treatment method |
| CN106395874A (en) * | 2016-10-08 | 2017-02-15 | 山西大学 | Method for extracting sodium chloride and aluminum chloride hexahydrate from mixed solution |
| CN108929708A (en) * | 2018-06-26 | 2018-12-04 | 浙江奇彩环境科技股份有限公司 | Sodium chloride abraum salt recycling processing method during a kind of DYE PRODUCTION |
| CN109911918A (en) * | 2019-05-07 | 2019-06-21 | 江苏迈克化工机械有限公司 | The resource utilization method of industrial mixed salt containing organic solvent |
| CN110451530A (en) * | 2019-08-16 | 2019-11-15 | 中国科学院过程工程研究所 | A kind of fine purification treatment process of industrial waste salt containing organic matter of desalinization of soil by flooding or leaching combination ex situ oxidation |
| CN111847480A (en) * | 2020-05-26 | 2020-10-30 | 南京工业大学 | Purification treatment and resource recycling method for industrial sodium chloride waste salt |
-
2021
- 2021-04-20 CN CN202110424968.7A patent/CN113149035B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2008174393A (en) * | 2007-01-16 | 2008-07-31 | Jfe Engineering Kk | Method for producing salt |
| CN105883859A (en) * | 2016-06-16 | 2016-08-24 | 浙江奇彩环境科技股份有限公司 | Waste salt treatment method |
| CN106395874A (en) * | 2016-10-08 | 2017-02-15 | 山西大学 | Method for extracting sodium chloride and aluminum chloride hexahydrate from mixed solution |
| CN108929708A (en) * | 2018-06-26 | 2018-12-04 | 浙江奇彩环境科技股份有限公司 | Sodium chloride abraum salt recycling processing method during a kind of DYE PRODUCTION |
| CN109911918A (en) * | 2019-05-07 | 2019-06-21 | 江苏迈克化工机械有限公司 | The resource utilization method of industrial mixed salt containing organic solvent |
| CN110451530A (en) * | 2019-08-16 | 2019-11-15 | 中国科学院过程工程研究所 | A kind of fine purification treatment process of industrial waste salt containing organic matter of desalinization of soil by flooding or leaching combination ex situ oxidation |
| CN111847480A (en) * | 2020-05-26 | 2020-10-30 | 南京工业大学 | Purification treatment and resource recycling method for industrial sodium chloride waste salt |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116495753A (en) * | 2023-04-26 | 2023-07-28 | 中国科学院生态环境研究中心 | Method for recycling industrial waste salt through recrystallization and purification |
| CN116495753B (en) * | 2023-04-26 | 2024-06-18 | 中国科学院生态环境研究中心 | Method for recycling industrial waste salt through recrystallization and purification |
Also Published As
| Publication number | Publication date |
|---|---|
| CN113149035B (en) | 2022-10-04 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| EP2247533B1 (en) | Process and apparatus for purifying solid salt compositions | |
| CN102531025B (en) | Method for treating rare earth ammonium chloride wastewater | |
| CN109911918B (en) | Resource utilization method of industrial mixed salt containing organic solvent | |
| CN109019634B (en) | Chemical waste salt refining and resource utilization system and method | |
| CN102092875B (en) | Chemical waste water treatment method in the process of producing 2,6 acid | |
| CN102583951A (en) | Acid lixiviation based recycling treatment method of aluminum circulating coagulation sludge | |
| CN110127925B (en) | Method for recycling mixed salt produced by waste acid treatment | |
| CN106430783A (en) | Ternary precursor waste water treatment system and treating method thereof | |
| US10683211B2 (en) | Process for potash recovery from biomethanated spent wash with concomitant environmental remediation of effluent | |
| CN108341536B (en) | Treatment method of epoxy resin production wastewater | |
| CN106007093A (en) | Zero discharge method for heavy metal waste water | |
| CN113149035B (en) | Method for treating waste sodium chloride salt | |
| CN104230082A (en) | Device for recovering sodium chloride and glycerol from high-salt glycerol-containing high-depth organic wastewater | |
| CN105948359A (en) | Treatment method for industrial wastewater of rare earth | |
| JP5267355B2 (en) | Method and apparatus for removing and collecting thallium from waste water | |
| CN111661979A (en) | Leachate recycling method and device | |
| CN104692566B (en) | A kind of processing method of aryltriazolinones high-salt wastewater | |
| CN107129081B (en) | 2B acid acidification wastewater treatment and resource recovery process | |
| CN113024005A (en) | Resource treatment process for hardly-degradable salt-containing organic wastewater | |
| CN111943297A (en) | Method for resourceful treatment of high-salinity high-organic wastewater | |
| CN111715664A (en) | Treatment method for recycling carbonized industrial waste salt | |
| CN109336330B (en) | Efficient treatment method of rubber accelerator wastewater | |
| CN114409157A (en) | Resource method for preparing chlor-alkali by electrolyzing waste brine | |
| CN104230084A (en) | Device for recovering sodium chloride and glycerinum from high-salinity and high-depth organic wastewater containing glycerinum | |
| CN109536740B (en) | Method for preparing cesium sulfate from salt-containing wastewater |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |