CN117228694A - Method for preparing baking soda by using desulfurized fly ash - Google Patents
Method for preparing baking soda by using desulfurized fly ash Download PDFInfo
- Publication number
- CN117228694A CN117228694A CN202311498165.1A CN202311498165A CN117228694A CN 117228694 A CN117228694 A CN 117228694A CN 202311498165 A CN202311498165 A CN 202311498165A CN 117228694 A CN117228694 A CN 117228694A
- Authority
- CN
- China
- Prior art keywords
- sodium
- bicarbonate
- sulfate
- baking soda
- sodium bicarbonate
- 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
- UIIMBOGNXHQVGW-UHFFFAOYSA-M Sodium bicarbonate Chemical compound [Na+].OC([O-])=O UIIMBOGNXHQVGW-UHFFFAOYSA-M 0.000 title claims abstract description 138
- 229910000030 sodium bicarbonate Inorganic materials 0.000 title claims abstract description 69
- 235000017557 sodium bicarbonate Nutrition 0.000 title claims abstract description 69
- 238000000034 method Methods 0.000 title claims abstract description 47
- 239000010881 fly ash Substances 0.000 title claims abstract description 13
- 239000002956 ash Substances 0.000 claims abstract description 39
- 238000006477 desulfuration reaction Methods 0.000 claims abstract description 36
- 230000023556 desulfurization Effects 0.000 claims abstract description 36
- 238000001816 cooling Methods 0.000 claims abstract description 20
- 238000006115 defluorination reaction Methods 0.000 claims abstract description 20
- 230000003647 oxidation Effects 0.000 claims abstract description 19
- 238000007254 oxidation reaction Methods 0.000 claims abstract description 19
- 238000001556 precipitation Methods 0.000 claims abstract description 15
- 238000002425 crystallisation Methods 0.000 claims abstract description 14
- 230000008025 crystallization Effects 0.000 claims abstract description 14
- -1 fluoride ions Chemical class 0.000 claims abstract description 10
- 238000004064 recycling Methods 0.000 claims abstract description 9
- BVKZGUZCCUSVTD-UHFFFAOYSA-M Bicarbonate Chemical compound OC([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-M 0.000 claims abstract description 8
- BVKZGUZCCUSVTD-UHFFFAOYSA-L Carbonate Chemical compound [O-]C([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-L 0.000 claims abstract description 8
- 230000020477 pH reduction Effects 0.000 claims abstract description 7
- 230000008878 coupling Effects 0.000 claims abstract description 5
- 238000010168 coupling process Methods 0.000 claims abstract description 5
- 238000005859 coupling reaction Methods 0.000 claims abstract description 5
- 238000004090 dissolution Methods 0.000 claims abstract description 5
- NRCHURFARBKHAO-UHFFFAOYSA-L disodium hydrogen carbonate hydrogen sulfate Chemical compound [Na+].[Na+].OC(O)=O.[O-]S([O-])(=O)=O NRCHURFARBKHAO-UHFFFAOYSA-L 0.000 claims abstract description 4
- SDCJMBBHNJPYGW-UHFFFAOYSA-L disodium;hydrogen carbonate;chloride Chemical compound [Na+].[Na+].Cl.[O-]C([O-])=O SDCJMBBHNJPYGW-UHFFFAOYSA-L 0.000 claims abstract description 4
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 claims description 49
- PMZURENOXWZQFD-UHFFFAOYSA-L Sodium Sulfate Chemical compound [Na+].[Na+].[O-]S([O-])(=O)=O PMZURENOXWZQFD-UHFFFAOYSA-L 0.000 claims description 43
- 239000000243 solution Substances 0.000 claims description 37
- 229910052938 sodium sulfate Inorganic materials 0.000 claims description 32
- 235000011152 sodium sulphate Nutrition 0.000 claims description 32
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 28
- ATRRKUHOCOJYRX-UHFFFAOYSA-N Ammonium bicarbonate Chemical compound [NH4+].OC([O-])=O ATRRKUHOCOJYRX-UHFFFAOYSA-N 0.000 claims description 26
- 229910000013 Ammonium bicarbonate Inorganic materials 0.000 claims description 26
- 235000012538 ammonium bicarbonate Nutrition 0.000 claims description 26
- 239000001099 ammonium carbonate Substances 0.000 claims description 26
- 239000011780 sodium chloride Substances 0.000 claims description 24
- NLXLAEXVIDQMFP-UHFFFAOYSA-N Ammonia chloride Chemical compound [NH4+].[Cl-] NLXLAEXVIDQMFP-UHFFFAOYSA-N 0.000 claims description 20
- 239000012452 mother liquor Substances 0.000 claims description 17
- 239000003795 chemical substances by application Substances 0.000 claims description 15
- 238000003756 stirring Methods 0.000 claims description 15
- OSGAYBCDTDRGGQ-UHFFFAOYSA-L calcium sulfate Chemical compound [Ca+2].[O-]S([O-])(=O)=O OSGAYBCDTDRGGQ-UHFFFAOYSA-L 0.000 claims description 12
- 239000000706 filtrate Substances 0.000 claims description 11
- UIIMBOGNXHQVGW-DEQYMQKBSA-M Sodium bicarbonate-14C Chemical class [Na+].O[14C]([O-])=O UIIMBOGNXHQVGW-DEQYMQKBSA-M 0.000 claims description 10
- 235000019270 ammonium chloride Nutrition 0.000 claims description 10
- BFNBIHQBYMNNAN-UHFFFAOYSA-N ammonium sulfate Chemical compound N.N.OS(O)(=O)=O BFNBIHQBYMNNAN-UHFFFAOYSA-N 0.000 claims description 10
- 229910052921 ammonium sulfate Inorganic materials 0.000 claims description 10
- 235000011130 ammonium sulphate Nutrition 0.000 claims description 10
- 239000007788 liquid Substances 0.000 claims description 10
- 238000001914 filtration Methods 0.000 claims description 9
- 239000010446 mirabilite Substances 0.000 claims description 9
- 230000001376 precipitating effect Effects 0.000 claims description 9
- 239000011737 fluorine Substances 0.000 claims description 8
- 229910052731 fluorine Inorganic materials 0.000 claims description 8
- GEHJYWRUCIMESM-UHFFFAOYSA-L sodium sulfite Chemical compound [Na+].[Na+].[O-]S([O-])=O GEHJYWRUCIMESM-UHFFFAOYSA-L 0.000 claims description 8
- 239000006228 supernatant Substances 0.000 claims description 8
- 239000001110 calcium chloride Substances 0.000 claims description 7
- 229910001628 calcium chloride Inorganic materials 0.000 claims description 7
- 230000001590 oxidative effect Effects 0.000 claims description 7
- 239000002244 precipitate Substances 0.000 claims description 7
- 239000000725 suspension Substances 0.000 claims description 7
- 239000000701 coagulant Substances 0.000 claims description 6
- 238000001035 drying Methods 0.000 claims description 6
- 239000000126 substance Substances 0.000 claims description 6
- QAOWNCQODCNURD-UHFFFAOYSA-N sulfuric acid Substances OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 claims description 6
- UXVMQQNJUSDDNG-UHFFFAOYSA-L Calcium chloride Chemical compound [Cl-].[Cl-].[Ca+2] UXVMQQNJUSDDNG-UHFFFAOYSA-L 0.000 claims description 4
- YCKRFDGAMUMZLT-UHFFFAOYSA-N Fluorine atom Chemical compound [F] YCKRFDGAMUMZLT-UHFFFAOYSA-N 0.000 claims description 4
- QAOWNCQODCNURD-UHFFFAOYSA-L Sulfate Chemical compound [O-]S([O-])(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-L 0.000 claims description 4
- 239000007864 aqueous solution Substances 0.000 claims description 4
- 239000011259 mixed solution Substances 0.000 claims description 4
- 235000010265 sodium sulphite Nutrition 0.000 claims description 4
- CBENFWSGALASAD-UHFFFAOYSA-N Ozone Chemical compound [O-][O+]=O CBENFWSGALASAD-UHFFFAOYSA-N 0.000 claims description 3
- 230000003197 catalytic effect Effects 0.000 claims description 3
- 238000006056 electrooxidation reaction Methods 0.000 claims description 3
- 238000010438 heat treatment Methods 0.000 claims description 3
- 230000001699 photocatalysis Effects 0.000 claims description 3
- 238000009279 wet oxidation reaction Methods 0.000 claims description 3
- 239000008236 heating water Substances 0.000 claims description 2
- 230000001105 regulatory effect Effects 0.000 claims description 2
- 230000001502 supplementing effect Effects 0.000 claims description 2
- 230000008569 process Effects 0.000 abstract description 14
- 238000011084 recovery Methods 0.000 abstract description 10
- 239000012535 impurity Substances 0.000 abstract description 5
- 150000002500 ions Chemical class 0.000 abstract description 4
- LSNNMFCWUKXFEE-UHFFFAOYSA-N Sulfurous acid Chemical compound OS(O)=O LSNNMFCWUKXFEE-UHFFFAOYSA-N 0.000 abstract description 2
- 238000009270 solid waste treatment Methods 0.000 abstract description 2
- 238000002360 preparation method Methods 0.000 abstract 2
- 239000007787 solid Substances 0.000 description 11
- 238000006243 chemical reaction Methods 0.000 description 8
- 239000000203 mixture Substances 0.000 description 8
- 239000011734 sodium Substances 0.000 description 7
- 239000010440 gypsum Substances 0.000 description 5
- 229910052602 gypsum Inorganic materials 0.000 description 5
- CDBYLPFSWZWCQE-UHFFFAOYSA-L Sodium Carbonate Chemical compound [Na+].[Na+].[O-]C([O-])=O CDBYLPFSWZWCQE-UHFFFAOYSA-L 0.000 description 4
- 230000003009 desulfurizing effect Effects 0.000 description 4
- 239000000047 product Substances 0.000 description 4
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 description 3
- 239000011575 calcium Substances 0.000 description 3
- 239000003245 coal Substances 0.000 description 3
- 238000004939 coking Methods 0.000 description 3
- 239000003546 flue gas Substances 0.000 description 3
- 230000004048 modification Effects 0.000 description 3
- 238000012986 modification Methods 0.000 description 3
- RSIJVJUOQBWMIM-UHFFFAOYSA-L sodium sulfate decahydrate Chemical compound O.O.O.O.O.O.O.O.O.O.[Na+].[Na+].[O-]S([O-])(=O)=O RSIJVJUOQBWMIM-UHFFFAOYSA-L 0.000 description 3
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 2
- JTXJZBMXQMTSQN-UHFFFAOYSA-N amino hydrogen carbonate Chemical compound NOC(O)=O JTXJZBMXQMTSQN-UHFFFAOYSA-N 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 238000001704 evaporation Methods 0.000 description 2
- 239000000618 nitrogen fertilizer Substances 0.000 description 2
- 229910000029 sodium carbonate Inorganic materials 0.000 description 2
- 239000002689 soil Substances 0.000 description 2
- 235000008733 Citrus aurantifolia Nutrition 0.000 description 1
- 239000007832 Na2SO4 Substances 0.000 description 1
- 235000011941 Tilia x europaea Nutrition 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 239000004566 building material Substances 0.000 description 1
- 239000006227 byproduct Substances 0.000 description 1
- 239000001569 carbon dioxide Substances 0.000 description 1
- 229910002092 carbon dioxide Inorganic materials 0.000 description 1
- 239000003153 chemical reaction reagent Substances 0.000 description 1
- 239000000571 coke Substances 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 239000003814 drug Substances 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005265 energy consumption Methods 0.000 description 1
- 230000008020 evaporation Effects 0.000 description 1
- 239000004571 lime Substances 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 239000008267 milk Substances 0.000 description 1
- 210000004080 milk Anatomy 0.000 description 1
- 235000013336 milk Nutrition 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 238000010587 phase diagram Methods 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 235000017550 sodium carbonate Nutrition 0.000 description 1
- 239000002910 solid waste Substances 0.000 description 1
- 239000008399 tap water Substances 0.000 description 1
- 235000020679 tap water Nutrition 0.000 description 1
Landscapes
- Processing Of Solid Wastes (AREA)
Abstract
The invention discloses a method for preparing baking soda by using desulfurized fly ash, and particularly relates to the technical field of solid waste treatment. The method comprises the steps of dissolution, coagulation-defluorination coupling precipitation defluorination, oxidation acidification, cooling crystallization, sodium sulfate sodium bicarbonate preparation, reverse precipitation and sodium chloride sodium bicarbonate preparation. The invention adopts an effective process to prepare the industrial desulfurization ash into the baking soda with high added value, and the baking soda is reused in the desulfurization process, thereby realizing the recycling of the industrial desulfurization ash. And the impurity ions COD, sulfite, carbonate, bicarbonate, fluoride ions and the like in the desulfurized ash are comprehensively removed, and compared with the traditional process, the purity and the recovery rate of the recovered baking soda are higher through technological innovation.
Description
Technical Field
The invention relates to the technical field of solid waste treatment, in particular to a method for preparing baking soda by using desulfurized fly ash.
Background
The flue gas desulfurization ash is first-grade dangerous solid waste generated in the flue gas desulfurization process of the coke oven by taking sodium carbonate and sodium bicarbonate as desulfurizing agents, wherein the main components are sodium carbonate, sodium bicarbonate, sodium sulfate, sodium sulfite and the like, and the flue gas desulfurization ash contains impurity ions in a certain proportion. The desulfurized fly ash is easy to dissolve in water, and when being piled up or buried, the desulfurized fly ash can infiltrate into soil after being drifted by rainwater, thereby causing serious pollution to soil and underground water.
Chinese patent CN11207363A proposes a method for recycling sodium bicarbonate desulfurization ash, which comprises dissolving desulfurization ash with pure water, clarifying, separating solid from liquid, adding sodium bicarbonate crystals into the clarified liquid, and evaporating and concentrating to obtain sodium bicarbonate product, wherein the technology does not mention the technology for removing impurity ions in the desulfurization ash, and the purity of the obtained sodium bicarbonate and sodium sulfate product cannot be ensured.
Chinese patent CN109850922a proposes a method and apparatus for recycling baking soda desulfurization ash, which uses the combined action of lime milk and carbon dioxide and oxygen to convert carbonate in the solution into bicarbonate on the basis of desulfurization ash dissolution and filtration, so as to improve the purity of baking soda and produce byproduct calcium sulfate, but the added value of calcium sulfate is lower than that of baking soda. And the purity of the recovered calcium sulfate cannot be ensured due to the existence of organic matters and fluoride ions in the desulfurized fly ash.
Chinese patent CN110697738A proposes a method for recycling sodium bicarbonate dry desulfurization ash, wherein desulfurization ash is recycled into sodium sulfate and sodium chloride, but the added value of sodium sulfate is lower than that of sodium bicarbonate for enterprises, and the sodium sulfate cannot be recycled in the enterprises.
Disclosure of Invention
To this end, the present invention provides a method for preparing baking soda using desulfurization ash to solve the above-mentioned problems.
The invention improves on the basis of the prior art, optimizes and perfects the impurity removal process in the process of recycling sodium bicarbonate from the desulfurization ash, converts sodium sulfate in the system into sodium bicarbonate, reduces the usage amount of a conversion reagent for converting sodium sulfate into sodium bicarbonate, and fully realizes the recycling of the desulfurization ash.
In order to achieve the above object, the present invention provides the following technical solutions:
according to the method for preparing baking soda by using desulfurization ash provided by the invention, the method comprises the following steps:
(1) dissolving: dissolving the desulfurized fly ash in water to obtain a suspension containing black suspended matters;
(2) coagulation-defluorination coupling precipitation defluorination: adding a defluorinating agent into the suspension containing the black suspended matters, removing suspended matters in the suspension containing the black suspended matters and precipitates formed by the defluorinating agent and fluoride ions by adopting a chemical defluorination method and utilizing a coagulation-defluorination coupling precipitation principle, and filtering supernatant after precipitation to obtain defluorination filtrate;
(3) oxidative acidification: oxidizing and acidizing the defluorination filtrate; oxidizing sodium sulfite in the solution into sodium sulfate, adding concentrated sulfuric acid for acidizing, regulating the pH value to 4.4, and converting carbonate and bicarbonate into sulfate radical to obtain sulfate mixed solution;
(4) cooling and crystallizing: cooling and crystallizing the sulfate mixed solution to obtain sodium sulfate precipitated in the form of mirabilite; cooling a part of mother liquor, supplementing water, heating and returning to the step (1), wherein the other part of mother liquor is used as a subsequent treatment liquid;
(5) sodium sulfate sodium bicarbonate: heating water to dissolve sodium sulfate to obtain sodium sulfate aqueous solution, adding ammonium bicarbonate into the sodium sulfate aqueous solution, converting sodium sulfate into sodium bicarbonate and ammonium sulfate, separating out supersaturated sodium bicarbonate, allowing the sodium bicarbonate to enter a drying system to prepare sodium bicarbonate, and recovering ammonium sulfate;
(6) reverse precipitation: adding calcium chloride into the subsequent treatment liquid in the step (4), and precipitating calcium sulfate precipitate and sodium chloride solution;
(7) sodium chloride sodium bicarbonate: adding ammonium bicarbonate into the sodium chloride solution in the step (6), converting sodium chloride into sodium bicarbonate and ammonium chloride, separating out supersaturated sodium bicarbonate, and enabling the sodium bicarbonate to enter a drying system to prepare sodium bicarbonate; and (5) recycling ammonium chloride.
Further, in the step (1), the dissolution temperature is 35-40 ℃; desulfurization ash: the mass ratio of water is 1:1-1:5.
Further, in the step (2), the chemical defluorination method comprises the steps of adding a defluorination agent according to a molar ratio of fluorine ions=1:1-2:1, stirring for reaction for 30-50 min, adding 200-1000 ppm of a coagulant, stirring for 5-10 min, precipitating for 1-2 h, removing the precipitate, and filtering the supernatant to obtain a defluorination filtrate.
Further, in the step (3), the oxidation method is one or a combination of several of chemical oxidation, wet oxidation, fenton oxidation, ozone catalytic oxidation, photocatalytic oxidation and electrochemical oxidation; acidification adjusts the pH to 4.4.
Further, in the step (4), the temperature of cooling crystallization is 5-15 ℃; the temperature of the heating is 35-40 ℃.
Further, in the step (5), the temperature of hot water is 50-60 ℃, and the concentration of sodium sulfate solution is 31%; the adding amount of the ammonium bicarbonate is that the molar ratio of the ammonium bicarbonate to the sodium sulfate is 1:1-1:10.
Further, in the step (7), the adding amount of the ammonium bicarbonate is that the molar ratio of the ammonium bicarbonate to the sodium chloride solution is 1:1-1:10.
The invention has the following advantages:
1) The invention adopts an effective process to prepare the industrial desulfurization ash into the baking soda with high added value, and the baking soda is reused in the desulfurization process, thereby realizing the recycling of the industrial desulfurization ash. And the impurity ions COD, sulfite, carbonate, bicarbonate, fluoride ions and the like in the desulfurized ash are comprehensively removed, and compared with the traditional process, the purity of the recovered baking soda is higher and the recovery rate is higher through an innovative process.
2) In the cooling crystallization salt separation process, according to Na 2 SO 4 -NaCl-H 2 O ternary phase diagram, reasonable control of temperature, ensuring precipitated Na 2 SO 4 Takes up Na in the solution 2 SO 4 The total content is more than 85 percent, and the mixture of anhydrous sodium sulfate with the purity of more than 98 percent and sodium bicarbonate is obtained;
3) By Na 2 SO 4 At a certain temperature with NaHCO 3 Solubility difference, na is added when ammonia bicarbonate is added 2 SO 4 All conversion to NaHCO 3 After NaHCO 3 Precipitation starts, the conversion rate reaches 90%, and two industrial products of sodium bicarbonate solid and ammonium sulfate are obtained.
4) The method is characterized in that calcium chloride is added into the cooled crystallization mother liquor to obtain gypsum and sodium chloride solution, and compared with the process of producing sodium chloride solid through evaporation and crystallization and then dissolving the sodium chloride solid into the sodium chloride solution, the energy consumption is greatly reduced.
5) NaHCO and NaCl at a certain temperature are utilized 3 Solubility difference, when adding ammonia bicarbonate, naCl is completely converted into NaHCO 3 After NaHCO 3 Precipitation starts, the conversion rate reaches 90%, and two industrial products of baking soda solid and ammonium chloride are obtained.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below. It will be apparent to those of ordinary skill in the art that the drawings in the following description are exemplary only and that other implementations can be obtained from the extensions of the drawings provided without inventive effort.
The structures, proportions, sizes, etc. shown in the present specification are shown only for the purposes of illustration and description, and are not intended to limit the scope of the invention, which is defined by the claims, so that any structural modifications, changes in proportions, or adjustments of sizes, which do not affect the efficacy or the achievement of the present invention, should fall within the ambit of the technical disclosure.
Fig. 1 is a process flow chart for preparing baking soda by using desulfurized fly ash.
Detailed Description
Other advantages and advantages of the present invention will become apparent to those skilled in the art from the following detailed description, which, by way of illustration, is to be read in connection with certain specific embodiments, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
A method for preparing baking soda by using desulfurized fly ash, the process flow is shown in figure 1, and the method comprises the following steps:
1) Dissolving: under the condition that the water temperature of the desulfurization ash is 35-40 ℃, the desulfurization ash is prepared by the following steps: water=1:1-1:5, wherein the water can be tap water, pure water, evaporated condensed water and the like, the desulphurized ash with the mass ratio of more than 98% is dissolved in the water, and insoluble matters are in a black suspension state;
2) Coagulation-defluorination coupled precipitation: the method adopts a chemical defluorination method, and the defluorination agent comprises the following components in mole ratio: adding fluorine ions=1:1-2:1, stirring and reacting for 30-50 min, adding 200-1000 ppm of coagulant, stirring for 5-10 min, precipitating for 1-2 h, removing insoluble matters dissolved in the step 1 and precipitates formed by defluorinating agent and fluorine ions together, reducing the fluorine ions of effluent to below 10mg/L, filtering the supernatant after precipitation, collecting filtrate and treating the filtrate for the next step;
3) Oxidative acidification: the oxidation process comprises one or a combination of a plurality of conventional medicament oxidation, wet oxidation, fenton oxidation, ozone catalytic oxidation, photocatalytic oxidation and electrochemical oxidation, sodium sulfite in the solution is completely oxidized into sodium sulfate, the decoloring effect on the solution is obvious, and the removal rate of organic matters is more than 90%; adding a proper amount of concentrated sulfuric acid into the oxidized solution for acidification, adjusting the pH value to 4.4, and completely converting carbonate radicals and bicarbonate radicals into sulfate radicals;
4) Cooling and crystallizing: cooling the solution treated in the step 3 to 5-15 ℃, wherein sodium sulfate in the solution is separated out in a mirabilite form; after 10% -20% of mother liquor after cooling crystallization is mixed with make-up water, the temperature is raised to 35-40 ℃ by a heat exchanger, the mixture flows back to a dissolving unit, and 80% -90% of mother liquor is collected and then treated in the next step;
5) Sodium sulfate sodium bicarbonate: dissolving the mirabilite obtained by cooling crystallization in 50-60 ℃ water until the concentration of Na2SO4 is 31%, adding ammonium bicarbonate in a molar ratio of 3:1-2:1 of ammonium bicarbonate to sodium sulfate, converting sodium sulfate into sodium bicarbonate and ammonium sulfate, wherein the recovery rate of the obtained sodium bicarbonate is more than 90%, and preparing sodium bicarbonate in a drying system, wherein the purity of the sodium bicarbonate is more than 95%, and the ammonium sulfate can be used as a nitrogenous fertilizer;
6) Reaction precipitation: adding a proper amount of calcium chloride into the residual mother liquor in the step 4, and precipitating and separating out residual sulfate radicals in the form of calcium sulfate, wherein the formed gypsum can be used as a building material; at this time, the main component of the residual solution is sodium chloride;
7) Sodium chloride sodium bicarbonate: and (3) adding ammonium bicarbonate into the sodium chloride solution obtained in the step (6) according to the molar ratio of 1.5:1-1:1, and converting sodium chloride into sodium bicarbonate and ammonium chloride, wherein the recovery rate of the obtained sodium bicarbonate is more than 90%, wherein the sodium bicarbonate and the sodium bicarbonate separated out in the step (5) are mixed and enter a drying system to prepare sodium bicarbonate, the purity of the sodium bicarbonate is more than 95%, and the ammonium chloride can be used as a nitrogenous fertilizer.
Example 1
The analysis of the desulfurization ash composition of a certain coal coking enterprise is shown in table 1:
TABLE 1 analysis results of the percentage of the desulfurization ash components
A method for preparing baking soda by using desulfurization ash shown in the components in table 1:
step 1: desulfurizing ash according to mass under the constant temperature condition of 40 ℃: water=1:4, in which black insolubles are present;
step 2: f is fluorine removing agent according to mole ratio - =1:1 adding defluorinating agent into the dissolution liquid, stirring and reacting for 30min, and thenAdding 500ppm coagulant, stirring for 8min, stopping stirring, precipitating for 1 hr, filtering supernatant, and detecting F - The content is 8.35mg/L, and the filtered liquid is yellow transparent.
Step 3: introducing the filtrate obtained in the step 2 into O 3 According to mole O 3 : COD=2:1, and after the oxidation is finished, the solution turns into colorless transparent, and the COD removal rate reaches 60%; and adding concentrated sulfuric acid to regulate pH to 4.4, and converting carbonate and bicarbonate into sulfate radical.
Step 4: cooling the solution obtained in the step 3 to 5 ℃, wherein a large amount of mirabilite is precipitated, the purity of the mirabilite is 98.5%, 10% of mother liquor after cooling crystallization is mixed with make-up water, the temperature is raised to 35-40 ℃ by a heat exchanger, the mixture is refluxed to a dissolving unit, and 90% of mother liquor is collected and then treated in the next step;
step 5: dissolving Natrii sulfas obtained in step 4 in water to Na 2 SO 4 And adding ammonium bicarbonate solid at a concentration of 31% and a molar ratio of ammonium bicarbonate to sodium sulfate of 2:1 to obtain sodium bicarbonate and ammonium sulfate, wherein the recovery rate of the obtained sodium bicarbonate is 89%.
Step 6: adding mole Ca into the cooled crystallization mother liquor in the step 4 2+ ：SO 4 2- Calcium chloride was added in a ratio of 1:1, reacted for 30min, precipitated for 1h, and filtered to give sodium chloride solution and gypsum.
Step 7: and (3) adding ammonium bicarbonate solid into the sodium chloride solution obtained in the step (6) according to the molar ratio of the ammonium bicarbonate to the sodium chloride of 1.5:1 to obtain sodium bicarbonate and ammonium chloride, wherein the recovery rate of the obtained sodium bicarbonate is 91%.
Example 2
The analysis of the desulfurization ash composition of a certain coal coking enterprise is shown in table 1; a method for preparing baking soda by using desulfurization ash shown in the components in table 1:
step 1: desulfurizing ash according to mass under the constant temperature condition of 38 ℃: water=1:3, in which black insolubles are present;
step 2: f is fluorine removing agent according to mole ratio - Adding defluorinating agent into the solution, stirring for reaction for 40min, adding 200ppm coagulant, stirring for 5min, stopping stirring, precipitating for 1.5 hr, filtering supernatant, and detectingF measurement - The content is 5.12mg/L, and the filtered liquid is yellow transparent.
Step 3: introducing the filtrate obtained in the step 2 into O 3 According to mole O 3 : COD=2:1, and after the oxidation is finished, the solution turns into colorless transparent, and the COD removal rate reaches 60%; and adding concentrated sulfuric acid to regulate pH to 4.4, and converting carbonate and bicarbonate into sulfate radical.
Step 4: cooling the solution obtained in the step 3 to 10 ℃, wherein a large amount of mirabilite is separated out, the purity of the mirabilite is 98.5%, 20% of mother liquor after cooling crystallization is mixed with make-up water, the temperature is raised to 35-40 ℃ by a heat exchanger, the mixture is refluxed to a dissolving unit, and 80% of mother liquor is collected and then treated in the next step;
step 5: dissolving Natrii sulfas obtained in step 4 in water to Na 2 SO 4 And adding ammonium bicarbonate solid at a concentration of 31% and a molar ratio of 2.5:1 of ammonium bicarbonate to sodium sulfate to obtain sodium bicarbonate and ammonium sulfate, wherein the recovery rate of the obtained sodium bicarbonate is 92%.
Step 6: adding mole Ca into the cooled crystallization mother liquor in the step 4 2+ ：SO 4 2- Calcium chloride was added in a ratio of 1:1, reacted for 30min, precipitated for 1h, and filtered to give sodium chloride solution and gypsum.
Step 7: the sodium chloride solution obtained in the step 6 is prepared by the following steps of: 1 adding ammonium bicarbonate solid to obtain sodium bicarbonate and ammonium chloride, wherein the recovery rate of the obtained sodium bicarbonate is 95%.
Example 3
The analysis of the desulfurization ash composition of a certain coal coking enterprise is shown in table 1; a method for preparing baking soda by using desulfurization ash shown in the components in table 1:
step 1: desulfurizing ash according to mass under the constant temperature condition of 35 ℃: water=1:5, in which black insolubles are present;
step 2: f is fluorine removing agent according to mole ratio - Adding defluorinating agent into the solution for stirring reaction for 50min, adding 1000ppm coagulant, stirring for 10min, stopping stirring, precipitating for 2h, filtering supernatant, and detecting F - The content is 1.52mg/L, and the filtered liquid is yellow transparent.
Step 3: introducing the filtrate obtained in the step 2 into O 3 According to mole O 3 : COD=2:1, and after the oxidation is finished, the solution turns into colorless transparent, and the COD removal rate reaches 60%; and adding concentrated sulfuric acid to regulate pH to 4.4, and converting carbonate and bicarbonate into sulfate radical.
Step 4: cooling the solution obtained in the step 3 to 15 ℃, wherein a large amount of mirabilite is separated out, the purity of the mirabilite is 98.5%, 20% of mother liquor after cooling crystallization is mixed with make-up water, the temperature is raised to 35-40 ℃ by a heat exchanger, the mixture is refluxed to a dissolving unit, and 80% of mother liquor is collected and then treated in the next step;
step 5: dissolving Natrii sulfas obtained in step 4 in water to Na 2 SO 4 And adding ammonium bicarbonate solid at a concentration of 31% and a molar ratio of ammonium bicarbonate to sodium sulfate of 3:1 to obtain sodium bicarbonate and ammonium sulfate, wherein the recovery rate of the obtained sodium bicarbonate is 95%.
Step 6: adding mole Ca into the cooled crystallization mother liquor in the step 4 2+ ：SO 4 2- Calcium chloride was added in a ratio of 1:1, reacted for 30min, precipitated for 1h, and filtered to give sodium chloride solution and gypsum.
Step 7: and (3) adding ammonium bicarbonate solid into the sodium chloride solution obtained in the step (6) according to the molar ratio of the ammonium bicarbonate to the sodium sulfate of 1:1 to obtain sodium bicarbonate and ammonium chloride, wherein the recovery rate of the obtained sodium bicarbonate is 98%.
While the invention has been described in detail in the foregoing general description and specific examples, it will be apparent to those skilled in the art that modifications and improvements can be made thereto. Accordingly, such modifications or improvements may be made without departing from the spirit of the invention and are intended to be within the scope of the invention as claimed.
Claims (7)
1. A method for preparing baking soda from desulfurized fly ash, the method comprising:
(1) dissolving: dissolving the desulfurized fly ash in water to obtain a suspension containing black suspended matters;
(2) coagulation-defluorination coupling precipitation defluorination: adding a defluorinating agent into the suspension containing the black suspended matters, removing suspended matters in the suspension containing the black suspended matters and precipitates formed by the defluorinating agent and fluoride ions by adopting a chemical defluorination method and utilizing a coagulation-defluorination coupling precipitation principle, and filtering supernatant after precipitation to obtain defluorination filtrate;
(3) oxidative acidification: oxidizing and acidizing the defluorination filtrate; oxidizing sodium sulfite in the solution into sodium sulfate, adding concentrated sulfuric acid for acidizing, regulating the pH value to 4.4, and converting carbonate and bicarbonate into sulfate radical to obtain sulfate mixed solution;
(4) cooling and crystallizing: cooling and crystallizing the sulfate mixed solution to obtain sodium sulfate precipitated in the form of mirabilite; cooling a part of mother liquor, supplementing water, heating and returning to the step (1), wherein the other part of mother liquor is used as a subsequent treatment liquid;
(5) sodium sulfate sodium bicarbonate: heating water to dissolve sodium sulfate to obtain sodium sulfate aqueous solution, adding ammonium bicarbonate into the sodium sulfate aqueous solution, converting sodium sulfate into sodium bicarbonate and ammonium sulfate, separating out supersaturated sodium bicarbonate, allowing the sodium bicarbonate to enter a drying system to prepare sodium bicarbonate, and recovering ammonium sulfate;
(6) reverse precipitation: adding calcium chloride into the subsequent treatment liquid in the step (4), and precipitating calcium sulfate precipitate and sodium chloride solution;
(7) sodium chloride sodium bicarbonate: adding ammonium bicarbonate into the sodium chloride solution in the step (6), converting sodium chloride into sodium bicarbonate and ammonium chloride, separating out supersaturated sodium bicarbonate, and enabling the sodium bicarbonate to enter a drying system to prepare sodium bicarbonate; and (5) recycling ammonium chloride.
2. The method for preparing baking soda by using desulfurization ash according to claim 1, wherein in the step (1), the dissolution temperature is 35-40 ℃; desulfurization ash: the mass ratio of water is 1:1-1:5.
3. The method for preparing baking soda by using desulfurization ash according to claim 1, wherein in the step (2), the method for chemically removing fluorine comprises the steps of adding a defluorinating agent, namely fluoride ions=1:1-2:1, stirring and reacting for 30-50 min, adding 200-1000 ppm of a coagulant and stirring for 5-10 min, precipitating for 1-2 h, removing the precipitate, and filtering supernatant to obtain a defluorinated filtrate.
4. The method for preparing baking soda by using desulfurized fly ash according to claim 1, wherein in the step (3), the oxidation method is one or a combination of several of chemical oxidation, wet oxidation, fenton oxidation, ozone catalytic oxidation, photo-catalytic oxidation and electrochemical oxidation; acidification adjusts the pH to 4.4.
5. The method for preparing baking soda by using desulfurization ash according to claim 1, wherein in the step (4), the temperature of cooling crystallization is 5-15 ℃; the temperature is 35-40 ℃ after the temperature is raised.
6. The method for preparing baking soda by using desulfurization ash according to claim 1, wherein in the step (5), the temperature of hot water is 50-60 ℃, and the concentration of sodium sulfate solution is 20-30%; the adding amount of the ammonium bicarbonate is that the molar ratio of the ammonium bicarbonate to the sodium sulfate is 1:1-1:10.
7. The method for preparing baking soda by using desulfurization ash according to claim 1, wherein in the step (7), the addition amount of ammonium bicarbonate is that the molar ratio of ammonium bicarbonate to sodium chloride solution is 1:1-1:10.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311498165.1A CN117228694B (en) | 2023-11-13 | 2023-11-13 | Method for preparing baking soda by using desulfurized fly ash |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311498165.1A CN117228694B (en) | 2023-11-13 | 2023-11-13 | Method for preparing baking soda by using desulfurized fly ash |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN117228694A true CN117228694A (en) | 2023-12-15 |
| CN117228694B CN117228694B (en) | 2024-01-26 |
Family
ID=89095164
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202311498165.1A Active CN117228694B (en) | 2023-11-13 | 2023-11-13 | Method for preparing baking soda by using desulfurized fly ash |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN117228694B (en) |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3998709A (en) * | 1974-09-26 | 1976-12-21 | Escher Wyss Limited | Treating remains containing sodium chloride and sodium sulphate |
| EP2103571A1 (en) * | 2008-03-18 | 2009-09-23 | Tata Chemicals Limited | A method of removing fluoride impurities from trona and preparation of sodium bicarbonate |
| CN112875726A (en) * | 2021-03-19 | 2021-06-01 | 宁波弗镁瑞环保科技有限公司 | Method for preparing sodium bicarbonate and calcium sulfate dihydrate by comprehensively utilizing sodium sulfate |
| CN216837159U (en) * | 2022-04-01 | 2022-06-28 | 北京赛科康仑环保科技有限公司 | System for utilize desulfurization ash to make baking soda |
| CN114751429A (en) * | 2022-04-01 | 2022-07-15 | 北京赛科康仑环保科技有限公司 | Treatment process for preparing baking soda from desulfurized ash |
| CN116282081A (en) * | 2023-05-17 | 2023-06-23 | 中国科学院过程工程研究所 | Method for preparing sodium bicarbonate from baking soda desulfurization ash |
-
2023
- 2023-11-13 CN CN202311498165.1A patent/CN117228694B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3998709A (en) * | 1974-09-26 | 1976-12-21 | Escher Wyss Limited | Treating remains containing sodium chloride and sodium sulphate |
| EP2103571A1 (en) * | 2008-03-18 | 2009-09-23 | Tata Chemicals Limited | A method of removing fluoride impurities from trona and preparation of sodium bicarbonate |
| CN112875726A (en) * | 2021-03-19 | 2021-06-01 | 宁波弗镁瑞环保科技有限公司 | Method for preparing sodium bicarbonate and calcium sulfate dihydrate by comprehensively utilizing sodium sulfate |
| CN216837159U (en) * | 2022-04-01 | 2022-06-28 | 北京赛科康仑环保科技有限公司 | System for utilize desulfurization ash to make baking soda |
| CN114751429A (en) * | 2022-04-01 | 2022-07-15 | 北京赛科康仑环保科技有限公司 | Treatment process for preparing baking soda from desulfurized ash |
| CN116282081A (en) * | 2023-05-17 | 2023-06-23 | 中国科学院过程工程研究所 | Method for preparing sodium bicarbonate from baking soda desulfurization ash |
Also Published As
| Publication number | Publication date |
|---|---|
| CN117228694B (en) | 2024-01-26 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US3551332A (en) | Purification of fluorine-containing industrial waste waters | |
| CN102491370B (en) | Method for producing ammonium bifluoride by recovering fluorine resource from fluorine-containing silicon slag | |
| CN102887535A (en) | Method for recycling high-purity fluorine and phosphorus from wastewater of phosphogypsum residue field | |
| CN114436297B (en) | Method for preparing sodium carbonate from mirabilite | |
| JPH0214808A (en) | Production of high purity silica and ammonium fluoride | |
| CN106277005B (en) | A kind of method that ice crystal, calcium carbonate and sodium sulphate are reclaimed in the resource from calcium fluoride sludge | |
| CN109516628A (en) | A method of extracting magnesium sulfate from high magnesium low calcium power plant effluent | |
| CN113086993A (en) | Process method for preparing potassium fluoride by decomposing fluosilicic acid through electrodialysis | |
| CN114751429B (en) | Treatment process for preparing baking soda from desulfurized fly ash | |
| CN113896209B (en) | Method for preparing sodium carbonate and byproducts potassium sulfate, ammonium sulfate and ammonium chloride from waste salt | |
| CN109336138B (en) | Method for separating potassium and sodium in mixed sulfate containing potassium and sodium | |
| CN113387374B (en) | Potassium removal process of ore lithium extraction production system | |
| CN112573556B (en) | Method for preparing nano calcium carbonate from calcium-containing solid waste residues and waste acids | |
| CN117228694B (en) | Method for preparing baking soda by using desulfurized fly ash | |
| CN107162935B (en) | The recovery method of phosphorus-containing compound in useless chemical polishing agent | |
| CN115403059B (en) | Method and system for recycling baking soda dry desulfurization ash | |
| CN110817827A (en) | Method for preparing food-grade monopotassium phosphate by using industrial wet-process purified phosphoric acid | |
| CN115010149B (en) | Method for recycling sodium sulfate and ammonium sulfate by mixed salt | |
| CN116282081A (en) | Method for preparing sodium bicarbonate from baking soda desulfurization ash | |
| CN114702047B (en) | Method for preparing sodium carbonate and co-producing ammonium sulfate by using sodium sulfate | |
| CN107640778B (en) | A method of the low cost recycling sodium sulphate from leaded desulfurization waste liquor | |
| CN110642317A (en) | Sodium sulfate wastewater resource utilization method | |
| CN113754164A (en) | Desulfurization wastewater treatment method and system | |
| CN113501535A (en) | Resource treatment method for household garbage incineration fly ash | |
| CN112340912A (en) | Method for recovering inorganic salt in ammonia desulphurization waste liquid |
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 |