CN114436228A - Process for preparing high-purity phosphoric acid by decolorizing denitrated and impurity-removed phosphoric acid - Google Patents
Process for preparing high-purity phosphoric acid by decolorizing denitrated and impurity-removed phosphoric acid Download PDFInfo
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- NBIIXXVUZAFLBC-UHFFFAOYSA-N Phosphoric acid Chemical compound OP(O)(O)=O NBIIXXVUZAFLBC-UHFFFAOYSA-N 0.000 title claims abstract description 134
- 229910000147 aluminium phosphate Inorganic materials 0.000 title claims abstract description 67
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 24
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 claims abstract description 52
- 239000003795 chemical substances by application Substances 0.000 claims abstract description 44
- 238000000605 extraction Methods 0.000 claims abstract description 30
- 238000007710 freezing Methods 0.000 claims abstract description 20
- 230000008014 freezing Effects 0.000 claims abstract description 20
- 159000000007 calcium salts Chemical class 0.000 claims abstract description 19
- 239000002367 phosphate rock Substances 0.000 claims abstract description 18
- OJMIONKXNSYLSR-UHFFFAOYSA-N phosphorous acid Chemical compound OP(O)O OJMIONKXNSYLSR-UHFFFAOYSA-N 0.000 claims abstract description 18
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 claims abstract description 17
- 239000013078 crystal Substances 0.000 claims abstract description 17
- 229910017604 nitric acid Inorganic materials 0.000 claims abstract description 17
- 229910019142 PO4 Inorganic materials 0.000 claims abstract description 16
- NBIIXXVUZAFLBC-UHFFFAOYSA-K phosphate Chemical compound [O-]P([O-])([O-])=O NBIIXXVUZAFLBC-UHFFFAOYSA-K 0.000 claims abstract description 14
- 239000010452 phosphate Substances 0.000 claims abstract description 14
- 239000006227 byproduct Substances 0.000 claims abstract description 12
- 238000001914 filtration Methods 0.000 claims abstract description 12
- 239000012141 concentrate Substances 0.000 claims abstract description 10
- 239000011575 calcium Substances 0.000 claims abstract description 8
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 claims abstract description 7
- 229910052791 calcium Inorganic materials 0.000 claims abstract description 7
- 239000002253 acid Substances 0.000 claims abstract description 6
- 238000001704 evaporation Methods 0.000 claims abstract description 6
- 239000000126 substance Substances 0.000 claims abstract description 6
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 17
- BHPQYMZQTOCNFJ-UHFFFAOYSA-N Calcium cation Chemical compound [Ca+2] BHPQYMZQTOCNFJ-UHFFFAOYSA-N 0.000 claims description 16
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 claims description 16
- 229910001424 calcium ion Inorganic materials 0.000 claims description 16
- 238000000034 method Methods 0.000 claims description 14
- 229910052799 carbon Inorganic materials 0.000 claims description 9
- 238000002425 crystallisation Methods 0.000 claims description 9
- 230000008025 crystallization Effects 0.000 claims description 9
- 239000002994 raw material Substances 0.000 claims description 8
- 239000004113 Sepiolite Substances 0.000 claims description 7
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims description 7
- 239000000835 fiber Substances 0.000 claims description 7
- 229910052624 sepiolite Inorganic materials 0.000 claims description 7
- 235000019355 sepiolite Nutrition 0.000 claims description 7
- 229910052979 sodium sulfide Inorganic materials 0.000 claims description 7
- GRVFOGOEDUUMBP-UHFFFAOYSA-N sodium sulfide (anhydrous) Chemical compound [Na+].[Na+].[S-2] GRVFOGOEDUUMBP-UHFFFAOYSA-N 0.000 claims description 7
- 239000003337 fertilizer Substances 0.000 claims description 6
- 238000001816 cooling Methods 0.000 claims description 5
- 238000010438 heat treatment Methods 0.000 claims description 5
- 230000008569 process Effects 0.000 claims description 5
- 239000007787 solid Substances 0.000 claims description 5
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 5
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 claims 3
- 230000000694 effects Effects 0.000 description 10
- AMQJEAYHLZJPGS-UHFFFAOYSA-N N-Pentanol Chemical compound CCCCCO AMQJEAYHLZJPGS-UHFFFAOYSA-N 0.000 description 8
- KBPLFHHGFOOTCA-UHFFFAOYSA-N caprylic alcohol Natural products CCCCCCCCO KBPLFHHGFOOTCA-UHFFFAOYSA-N 0.000 description 8
- 238000006243 chemical reaction Methods 0.000 description 6
- 229910021645 metal ion Inorganic materials 0.000 description 6
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 4
- 230000008859 change Effects 0.000 description 4
- 230000000052 comparative effect Effects 0.000 description 4
- HPXRVTGHNJAIIH-UHFFFAOYSA-N cyclohexanol Chemical compound OC1CCCCC1 HPXRVTGHNJAIIH-UHFFFAOYSA-N 0.000 description 4
- 239000003712 decolorant Substances 0.000 description 4
- 239000003350 kerosene Substances 0.000 description 4
- TVMXDCGIABBOFY-UHFFFAOYSA-N n-Octanol Natural products CCCCCCCC TVMXDCGIABBOFY-UHFFFAOYSA-N 0.000 description 4
- QAOWNCQODCNURD-UHFFFAOYSA-L Sulfate Chemical compound [O-]S([O-])(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-L 0.000 description 3
- 239000000203 mixture Substances 0.000 description 3
- 238000004064 recycling Methods 0.000 description 3
- 239000002699 waste material Substances 0.000 description 3
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 description 2
- 239000005909 Kieselgur Substances 0.000 description 2
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 2
- 229910052785 arsenic Inorganic materials 0.000 description 2
- RQNWIZPPADIBDY-UHFFFAOYSA-N arsenic atom Chemical compound [As] RQNWIZPPADIBDY-UHFFFAOYSA-N 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- ZCCIPPOKBCJFDN-UHFFFAOYSA-N calcium nitrate Chemical compound [Ca+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O ZCCIPPOKBCJFDN-UHFFFAOYSA-N 0.000 description 2
- 229910052593 corundum Inorganic materials 0.000 description 2
- 238000004042 decolorization Methods 0.000 description 2
- 229910001385 heavy metal Inorganic materials 0.000 description 2
- 229910052742 iron Inorganic materials 0.000 description 2
- JEIPFZHSYJVQDO-UHFFFAOYSA-N iron(III) oxide Inorganic materials O=[Fe]O[Fe]=O JEIPFZHSYJVQDO-UHFFFAOYSA-N 0.000 description 2
- 229910001845 yogo sapphire Inorganic materials 0.000 description 2
- 238000005903 acid hydrolysis reaction Methods 0.000 description 1
- 229910052925 anhydrite Inorganic materials 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- OSGAYBCDTDRGGQ-UHFFFAOYSA-L calcium sulfate Chemical compound [Ca+2].[O-]S([O-])(=O)=O OSGAYBCDTDRGGQ-UHFFFAOYSA-L 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- 229910052745 lead Inorganic materials 0.000 description 1
- YIXJRHPUWRPCBB-UHFFFAOYSA-N magnesium nitrate Inorganic materials [Mg+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O YIXJRHPUWRPCBB-UHFFFAOYSA-N 0.000 description 1
- 230000010534 mechanism of action Effects 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 239000005416 organic matter Substances 0.000 description 1
- 239000003960 organic solvent Substances 0.000 description 1
- 150000003016 phosphoric acids Chemical class 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
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-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B25/00—Phosphorus; Compounds thereof
- C01B25/16—Oxyacids of phosphorus; Salts thereof
- C01B25/18—Phosphoric acid
- C01B25/22—Preparation by reacting phosphate-containing material with an acid, e.g. wet process
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B25/00—Phosphorus; Compounds thereof
- C01B25/16—Oxyacids of phosphorus; Salts thereof
- C01B25/18—Phosphoric acid
- C01B25/22—Preparation by reacting phosphate-containing material with an acid, e.g. wet process
- C01B25/2208—Preparation by reacting phosphate-containing material with an acid, e.g. wet process with an acid or a mixture of acids other than sulfuric acid
- C01B25/2216—Preparation by reacting phosphate-containing material with an acid, e.g. wet process with an acid or a mixture of acids other than sulfuric acid with nitric acid or nitrous vapours in aqueous medium
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B25/00—Phosphorus; Compounds thereof
- C01B25/16—Oxyacids of phosphorus; Salts thereof
- C01B25/18—Phosphoric acid
- C01B25/234—Purification; Stabilisation; Concentration
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B25/00—Phosphorus; Compounds thereof
- C01B25/16—Oxyacids of phosphorus; Salts thereof
- C01B25/18—Phosphoric acid
- C01B25/234—Purification; Stabilisation; Concentration
- C01B25/237—Selective elimination of impurities
- C01B25/238—Cationic impurities, e.g. arsenic compounds
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2006/00—Physical properties of inorganic compounds
- C01P2006/80—Compositional purity
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- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Inorganic Chemistry (AREA)
- Fertilizers (AREA)
- Extraction Or Liquid Replacement (AREA)
Abstract
The invention discloses a process for preparing high-purity phosphoric acid by decoloring denitrated and impurity-removed phosphoric acid, which comprises the following steps: s1: decomposing the phosphorite/phosphate concentrate by using acidolysis solution; s2: filtering the solution decomposed in the step S1 to remove acid insoluble substances to obtain a first solution; s3: freezing and crystallizing the first solution in the S2 to remove partial calcium salt crystals to obtain a second solution; s4: adding sulfuric acid into the second solution in the S3 solution, filtering, and removing calcium to obtain a third solution; s5: evaporating the third solution in the S4 to remove nitric acid in the solution to obtain a fourth solution; s6: adding a decoloring agent into the fourth solution in the S5 for decoloring to obtain a decoloring byproduct and a fifth solution; s7: and adding a first extracting agent into the fifth solution in the S6 for extraction to obtain an extraction phase, and then back-extracting the extraction phase by using a second extracting agent to obtain the high-purity phosphoric acid solution. The invention improves the purity and yield of the prepared phosphoric acid.
Description
Technical Field
The invention relates to the technical field of phosphoric acid production, in particular to a process for preparing high-purity phosphoric acid by decoloring denitrated and impurity-removed phosphoric acid.
Background
At present, for preparing high-purity phosphoric acid from non-calcined phosphorite, the solution obtained after acidolysis treatment inevitably has color, and the extracted solution is mainly decolorized by a decolorizing agent in the existing treatment mode. However, since the extractant is an organic solvent, the carbonized organic matter is easily absorbed, thereby affecting the subsequent decoloring step. Therefore, it is highly desired to develop a method capable of efficiently producing high-purity phosphoric acid.
Disclosure of Invention
Based on the technical problems in the background art, the invention provides a process for preparing high-purity phosphoric acid by decoloring denitrated and impurity-removed phosphoric acid, and the purity and yield of the prepared phosphoric acid are improved.
The invention provides a process for preparing high-purity phosphoric acid by decoloring denitrated and impurity-removed phosphoric acid, which comprises the following steps:
s1: decomposing the phosphorite/phosphate concentrate by using acidolysis solution;
s2: filtering the solution decomposed in the step S1 to remove acid insoluble substances to obtain a first solution;
s3: freezing and crystallizing the first solution in the S2 to remove partial calcium salt crystals to obtain a second solution;
s4: adding sulfuric acid into the second solution in the S3 solution, filtering, and removing calcium to obtain a third solution;
s5: evaporating the third solution in the step S4 to obtain a fourth solution;
s6: adding a decoloring agent into the fourth solution in the S5 for decoloring to obtain a decoloring byproduct and a fifth solution;
s7: and adding a first extracting agent into the fifth solution in the S6 for extraction to obtain an extraction phase, and then back-extracting the extraction phase by using a second extracting agent to obtain the high-purity phosphoric acid solution.
Preferably, the acidolysis solution in S1 is one or more of a nitric acid solution, a hydrochloric acid solution and a phosphoric acid solution, and at least contains nitric acid or hydrochloric acid.
Preferably, the liquid-solid ratio of the acidolysis solution to the phosphorite/phosphate concentrate is 1-4: 1.
Preferably, the conditions for freezing and crystallizing in S3 are: keeping at-6 deg.C to-4 deg.C for 5-10min, heating to 4-6 deg.C at a rate of 1-3 deg.C/min for 5-10min, cooling to-6 deg.C to-4 deg.C at a rate of 1-3 deg.C/min for 5-10min, and storing for 40-60 min.
Preferably, the sulfuric acid in said S4 is added in a molar amount, calculated as the molar amount of sulfate, lower than the molar amount of calcium ions in the second solution.
Preferably, the decoloring agent in S6 comprises activated carbon, diatomaceous earth, sepiolite fiber and sodium sulfide, wherein the mass ratio of the activated carbon to the diatomaceous earth to the sepiolite fiber to the sodium sulfide is 10-20: 5-15: 1-10: 1-5, and the addition amount of the decoloring agent is 10-30 g/L.
Preferably, the volume ratio of the first extracting agent to the fifth solution in the S7 is 0.5-1.5: 1; the volume ratio of the second extractant to the extract phase is 0.4-0.8: 1.
Preferably, the first extracting agent comprises the following raw materials in parts by weight: 10-20 parts of n-octanol, 3-8 parts of n-pentanol, 5-10 parts of cyclohexanol and 5-10 parts of kerosene.
Preferably, the second extractant is water.
The invention provides an application of a decolored byproduct obtained by the process for preparing high-purity phosphoric acid by decoloring denitrated and impurity-removed phosphoric acid in organic carbon fertilizer.
Compared with the prior art, the invention has the beneficial technical effects that:
(1) the invention ensures that the extractant is not influenced by carbonized organic matters by decoloring before extracting impurity-removed metal ions, and improves the recycling effect of the extractant.
(2) The invention adopts the mode of temperature change treatment in the freezing and crystallizing stage, improves the formation amount of calcium salt crystals, thereby improving the removal efficiency of calcium ions and reducing the load of subsequent treatment.
(3) The decoloring agent can remove a part of metal ions while decoloring, thereby reducing the load of the subsequent extraction process and further improving the extraction efficiency.
(4) The decoloration by-product generated after the solution is decolored by the decolorant can be used for the production of organic carbon fertilizer, thereby improving the utilization rate of resources.
(5) According to the invention, the phosphoric acid solution obtained by extracting with the first extractant and back-extracting with the second extractant has high purity and yield.
Drawings
FIG. 1 is a flow chart of a process for preparing high-purity phosphoric acid by decolorizing denitrated and decontaminated phosphoric acid according to the present invention.
Detailed Description
The components of the phosphate ores used in the examples of the present invention were measured, and the results are shown in table 1.
TABLE 1 weight composition of each main component in phosphorite
| Components | P2O5 | CaO | MgO | Fe2O3 | Al2O3 | F |
| Percentage by weight (%) | 21.5 | 43.6 | 0.27 | 0.74 | 1.51 | 2.5 |
For the acid hydrolysis of phosphate ore, taking the example of dissolving phosphate ore by nitric acid, the related reaction is as follows:
Ca5F(PO4)3+10HNO3=5Ca(NO3)2+3H3PO4+HF；
CaO+2HNO3=Ca(NO3)2+H2O；
MgO+2HNO3=Mg(NO3)2+H2O；
Fe2O3+6HNO3=2Fe(NO3)3+3H2O；
Al2O3+6HNO3=2Al(NO3)3+3H2O。
example 1
The invention provides a process for preparing high-purity phosphoric acid by decoloring denitrated and impurity-removed phosphoric acid, which comprises the following steps:
s1: decomposing the phosphorite/phosphate concentrate by using acidolysis solution;
s2: filtering the solution decomposed in the step S1 to remove acid insoluble substances to obtain a first solution;
s3: freezing and crystallizing the first solution in the S2 to remove partial calcium salt crystals to obtain a second solution;
s4: adding sulfuric acid into the second solution in the S3, filtering, and removing calcium to obtain a third solution;
s5: evaporating the third solution in the S4 to remove nitric acid in the solution to obtain a fourth solution;
s6: adding a decoloring agent into the fourth solution in the S5 for decoloring to obtain a decoloring byproduct and a fifth solution;
s7: and adding a first extracting agent into the fifth solution in the S6 for extraction to obtain an extraction phase, and then back-extracting the extraction phase by using a second extracting agent to obtain the high-purity phosphoric acid solution.
Wherein: the acidolysis solution in S1 is a nitric acid solution, and the acidolysis reaction of the nitric acid solution on the phosphorite is as described above, wherein the mass concentration of the nitric acid solution in this example is 40%, and the liquid-solid ratio of the nitric acid solution to the phosphorite is 3:1, wherein the amount of the nitric acid is the same. By adding a little excessive nitric acid solution, the phosphorite can be basically and completely acidolyzed, so that the yield of subsequent phosphoric acid is improved, and the waste of resources is avoided.
The conditions for the freezing crystallization in S3 are as follows: maintaining at-5 deg.C for 8min, heating to 5 deg.C at 2 deg.C/min for 8min, cooling to-5 deg.C at 2 deg.C/min for 8min, and storing for 50 min. The main purpose of the freezing crystallization of the invention is to remove part of calcium salt crystals in the first solution, and the application finds that more calcium salt crystals can be generated compared with the constant temperature treatment method by adopting the temperature change treatment method, thereby improving the removal efficiency of calcium ions and reducing the load of subsequent treatment.
To further remove calcium ions from the solution, the solution is treated by adding sulfuric acid to the solutionIn theory, the volume ratio of the sulfuric acid to the second solution in S4 is 1:2, the added sulfuric acid is 98% concentrated sulfuric acid, and since part of calcium ions are removed in the process of cold freezing crystallization in S3, the addition amount of the sulfuric acid in this step is 102% of the theoretical amount of sulfuric acid required for complete reaction with the remaining calcium ions in the solution, wherein the mechanism of action of the sulfuric acid for removing the calcium ions in the solution is as follows: ca (NO)3)2+H2SO4=2HNO3+CaSO4↓。
The decoloring agent in the S6 comprises the following raw materials in parts by weight: 15 parts of active carbon, 10 parts of diatomite, 5 parts of sepiolite fiber and 3 parts of sodium sulfide; the addition amount of the decoloring agent is 20 g/L.
The decoloring agent can remove a part of metal ions while decoloring, thereby reducing the load of the subsequent extraction process and further improving the extraction efficiency; the decoloration by-product generated after the solution is decolored by the decolorant can be used for the production of organic carbon fertilizer, thereby improving the utilization rate of resources.
The volume ratio of the first extracting agent to the fifth solution in the S7 is 1: 1; the volume ratio of the second extractant to the extract phase was 0.6: 1.
Specifically, the first extracting agent comprises the following raw materials in parts by weight: 15 parts of n-octanol, 6 parts of n-pentanol, 8 parts of cyclohexanol and 8 parts of kerosene; the second extractant is water.
Example 2
The invention provides a process for preparing high-purity phosphoric acid by decoloring denitrated and impurity-removed phosphoric acid, which comprises the following steps:
s1: decomposing the phosphorite/phosphate concentrate by using acidolysis solution;
s2: filtering the solution decomposed in the step S1 to remove acid insoluble substances to obtain a first solution;
s3: freezing and crystallizing the first solution in the S2, and removing partial calcium salt crystals to obtain a second solution;
s4: adding sulfuric acid into the second solution in the S3 solution, filtering, and removing calcium to obtain a third solution;
s5: evaporating the third solution in the step S4 to obtain a fourth solution;
s6: adding a decoloring agent into the fourth solution in the S5 for decoloring to obtain a decoloring byproduct and a fifth solution;
s7: and adding a first extracting agent into the fifth solution in the S6 for extraction to obtain an extraction phase, and then back-extracting the extraction phase by using a second extracting agent to obtain the high-purity phosphoric acid solution.
Wherein: the acidolysis solution in the S1 is hydrochloric acid solution; the liquid-solid ratio of acidolysis solution to phosphorite/phosphate concentrate is 2: 1; wherein the amount of the hydrochloric acid is 110 percent of the theoretical amount of the hydrochloric acid required for completely reacting with each component in the phosphorite. Through adding excessive hydrochloric acid solution, the phosphorite can be guaranteed to be basically and completely acidolyzed, so that the yield of subsequent phosphoric acid is improved, and the waste of resources is avoided.
The conditions for the freezing crystallization in S3 are as follows: maintaining at-6 deg.C for 5min, heating to 6 deg.C at 1 deg.C/min for 5min, cooling to-6 deg.C at 1 deg.C/min for 5min, and storing for 40 min. The main purpose of the freezing crystallization of the invention is to remove part of calcium salt crystals in the first solution, and the application finds that more calcium salt crystals can be generated compared with the constant temperature treatment method by adopting the temperature change treatment method, thereby improving the removal efficiency of calcium ions and reducing the load of subsequent treatment.
In order to further remove calcium ions in the solution, the solution was treated by adding sulfuric acid to the solution, wherein the volume ratio of sulfuric acid to the second solution in S4 was 1: 1. The sulfuric acid added is 98% concentrated sulfuric acid, and since a part of calcium ions have been removed in the cold freezing process in S3, the amount of sulfuric acid added in this step is 102% of the theoretical amount of sulfuric acid required for complete reaction with the remaining calcium ions in the solution.
The decoloring agent in the S6 comprises the following raw materials in parts by weight: 10 parts of active carbon, 5 parts of diatomite, 1 part of sepiolite fiber and 1 part of sodium sulfide; the addition amount of the decoloring agent is 10 g/L.
The decoloring agent can remove a part of metal ions while decoloring, thereby reducing the load of the subsequent extraction process and further improving the extraction efficiency; the decoloration by-product generated after the solution is decolored by the decolorant can be used for the production of organic carbon fertilizer, thereby improving the utilization rate of resources.
The volume ratio of the first extracting agent to the fifth solution in the S7 is 0.5: 1; the volume ratio of the second extractant to the extract phase was 0.4: 1.
Specifically, the first extracting agent comprises the following raw materials in parts by weight: 20 parts of n-octanol, 8 parts of n-pentanol, 10 parts of cyclohexanol and 10 parts of kerosene; the second extractant is water.
Example 3
The invention provides a process for preparing high-purity phosphoric acid by decoloring denitrated and impurity-removed phosphoric acid, which comprises the following steps:
s1: decomposing the phosphorite/phosphate concentrate by using acidolysis solution;
s2: filtering the solution decomposed in the step S1 to remove acid insoluble substances to obtain a first solution;
s3: freezing and crystallizing the first solution in the S2 to remove partial calcium salt crystals to obtain a second solution;
s4: adding sulfuric acid into the second solution in the S3 solution, filtering, and removing calcium to obtain a third solution;
s5: evaporating the third solution in the step S4 to obtain a fourth solution;
s6: adding a decoloring agent into the fourth solution in the S5 for decoloring to obtain a decoloring byproduct and a fifth solution;
s7: and adding a first extracting agent into the fifth solution in the S6 for extraction to obtain an extraction phase, and then back-extracting the extraction phase by using a second extracting agent to obtain a high-purity phosphoric acid solution.
Wherein: the acidolysis solution in the S1 is a solution formed by mixing nitric acid and phosphoric acid according to a ratio of 3: 1; the liquid-solid ratio of the acidolysis solution to the phosphorite/phosphate concentrate is 4: 1; wherein the amount of nitric acid and the amount of phosphoric acid are 105% of the theoretical amount required for complete reaction with the components of the phosphate ore. By adding a little excessive nitric acid solution, the phosphorite can be basically and completely acidolyzed, so that the yield of subsequent phosphoric acid is improved, and the waste of resources is avoided.
The conditions for the freezing crystallization in S3 are as follows: maintaining at-4 deg.C for 10min, heating to 4 deg.C at 3 deg.C/min for 10min, cooling to-4 deg.C at 3 deg.C/min for 10min, and storing for 60 min. The main purpose of the freezing crystallization of the invention is to remove part of calcium salt crystals in the first solution, and the application finds that more calcium salt crystals can be generated compared with the constant temperature treatment method by adopting the temperature change treatment method, thereby improving the removal efficiency of calcium ions and reducing the load of subsequent treatment.
In order to further remove calcium ions in the solution, the solution was treated by adding sulfuric acid to the solution, wherein the volume ratio of sulfuric acid to the second solution in S4 was 1: 3. The sulfuric acid added is 98% concentrated sulfuric acid, and since a part of calcium ions have been removed in the cold freezing process in S3, the amount of sulfuric acid added in this step is 102% of the theoretical amount of sulfuric acid required for complete reaction with the remaining calcium ions in the solution.
The decoloring agent in the S6 comprises the following raw materials in parts by weight: 20 parts of active carbon, 15 parts of diatomite, 10 parts of sepiolite fiber and 5 parts of sodium sulfide; the addition amount of the decoloring agent is 30 g/L.
The decoloring agent can remove a part of metal ions while decoloring, thereby reducing the load of the subsequent extraction process and further improving the extraction efficiency; the decoloration by-product generated after the solution is decolored by the decolorant can be used for the production of organic carbon fertilizer, thereby improving the utilization rate of resources.
The volume ratio of the first extracting agent to the fifth solution in the S7 is 1.5: 1; the volume ratio of the second extractant to the extract phase was 0.8: 1.
Wherein the first extracting agent comprises the following raw materials in parts by weight: 20 parts of n-octanol, 8 parts of n-pentanol, 10 parts of cyclohexanol and 10 parts of kerosene; the second extractant is water.
The phosphoric acid solution prepared in examples 1-3 was prepared into 85% technical grade phosphoric acid by the prior art, and then the composition and chromaticity of the phosphoric acid solution were measured (refer to GB/T2091-2008), and the results are shown in Table 2.
TABLE 2 phosphoric acid composition and color
| Group of | Example 1 | Example 2 | Example 3 |
| Colour intensity | 13 | 18 | 16 |
| Chloride (as Cl, w/%) | ＜0.0004 | ＜0.0005 | ＜0.0005 |
| Sulfate (in SO)4Meter, w/%) | ＜0.001 | ＜0.003 | ＜0.002 |
| Iron (w/%) | ＜0.001 | ＜0.002 | ＜0.002 |
| Arsenic (w/%) | ＜0.0001 | ＜0.0001 | ＜0.0001 |
| Heavy metals (as Pb, w/%) | ＜0.0005 | ＜0.001 | ＜0.001 |
As can be seen from Table 1, the phosphoric acid prepared by the method has very low contents of chloride, sulfate, iron, arsenic, heavy metals and the like, which indicates that the phosphoric acid prepared by the method has very high purity, and the chromaticity of the phosphoric acid is lower than the standard (less than or equal to 20) of industrial phosphoric acid by detecting, which indicates that the decolorizing agent has very good decolorizing effect on the phosphoric acid.
Comparative example 1
In order to prove the influence of the temperature-changing manner on the formation of the calcium salt crystals in the freezing and crystallizing stage, the first solution of S2 in example 1 is stored for 50min at the temperature of-5 ℃, and then the solution and the amount of the calcium salt crystals formed in example 1 are respectively measured, so that the total mass of the calcium salt crystals formed in example 1 is 53.4g, while the total mass of the calcium salt crystals formed in comparative example 1 is only 37.8g, namely the total mass of the calcium salt removed by the temperature-changing treatment in example 1 is more than 1.4 times of the total mass of the calcium salt removed by the temperature-changing storage manner in comparative example 1, and the temperature-changing and freezing crystallization manner has a better calcium removal effect.
Comparative example 2
In order to demonstrate the influence of the decolorization sequence adjustment of the present invention on the recycling effect of the extractant, the extraction effect of the first extractant and the second extractant in example 1 is about 80% of the extraction effect in the first use after the first extractant and the second extractant are recycled for 10 times, and the extraction effect of the first extractant and the second extractant in example 1 is only about 50% of the extraction effect in the first use after the first extractant and the second extractant are recycled for 10 times after the first extractant and the second extractant are sequentially exchanged, which demonstrates that the present invention ensures that the extractant is not influenced by carbonized organic matters by decolorization before impurity metal ions are extracted and improves the recycling effect of the extractant.
The present invention is not limited to the above preferred embodiments, and any modifications, equivalent substitutions, improvements, etc. within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (10)
1. A process for preparing high-purity phosphoric acid by decoloring denitrated and impurity-removed phosphoric acid is characterized by comprising the following steps:
s1: decomposing the phosphorite/phosphate concentrate by using acidolysis solution;
s2: filtering the solution decomposed in the step S1 to remove acid insoluble substances to obtain a first solution;
s3: freezing and crystallizing the first solution in the S2 to remove partial calcium salt crystals to obtain a second solution;
s4: adding sulfuric acid into the second solution in the S3 solution, filtering, and removing calcium to obtain a third solution;
s5: evaporating the third solution in the step S4 to obtain a fourth solution;
s6: adding a decoloring agent into the fourth solution in the S5 for decoloring to obtain a decoloring byproduct and a fifth solution;
s7: and adding a first extracting agent into the fifth solution in the S6 for extraction to obtain an extraction phase, and then back-extracting the extraction phase by using a second extracting agent to obtain the high-purity phosphoric acid solution.
2. The process for preparing high-purity phosphoric acid by decoloring denitrated and impurity-removed phosphoric acid according to claim 1, wherein the acidolysis solution in the S1 is one or more of a nitric acid solution, a hydrochloric acid solution and a phosphoric acid solution, and at least contains nitric acid or hydrochloric acid.
3. The process for preparing high-purity phosphoric acid by decoloring denitrated and impurity-removed phosphoric acid according to claim 1 or 2, wherein the liquid-solid ratio of the acidolysis solution to the phosphorite/phosphate concentrate is 1-4:1, and the concentration of the nitric acid is 40-70%.
4. The process for preparing high-purity phosphoric acid by decoloring denitrated and impurity-removed phosphoric acid according to claim 1, wherein the conditions of the freezing crystallization in the S3 are as follows: keeping at-6 deg.C to-4 deg.C for 5-10min, heating to 4-6 deg.C at a rate of 1-3 deg.C/min for 5-10min, cooling to-6 deg.C to-4 deg.C at a rate of 1-3 deg.C/min for 5-10min, and storing for 40-60 min.
5. The process of claim 1, wherein the sulfuric acid in the S4 is added in a molar amount, calculated as sulfate radicals, lower than the molar amount of calcium ions in the second solution.
6. The process for preparing high-purity phosphoric acid by decoloring denitrated and impurity-removed phosphoric acid according to claim 1, wherein the decoloring agent in the S6 comprises activated carbon, diatomite, sepiolite fibers and sodium sulfide, wherein the mass ratio of the activated carbon to the diatomite to the sepiolite fibers to the sodium sulfide is 10-20: 5-15: 1-10: 1-5, and the addition amount of the decoloring agent is 10-30 g/L.
7. The process for preparing high-purity phosphoric acid by decoloring denitrated and impurity-removed phosphoric acid according to claim 1, wherein the volume ratio of the first extracting agent to the fifth solution in the S7 is 0.5-1.5: 1; the volume ratio of the second extractant to the extract phase is 0.4-0.8: 1.
8. The process for preparing high-purity phosphoric acid by decoloring denitrated and impurity-removed phosphoric acid according to claim 7, wherein the first extracting agent comprises the following raw materials in parts by weight: the methanol gasoline comprises the following components in percentage by mass: 10-20: 3-8: 5-10: 5-10.
9. The process for preparing high-purity phosphoric acid by decoloring denitrated and dedoped phosphoric acid according to claim 7, wherein the second extractant is water.
10. Use of a decolorized by-product obtained by the process for producing high-purity phosphoric acid by decolorizing denitrated and purified phosphoric acid according to any of claims 1 to 9 in an organic carbon fertilizer.
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115535982A (en) * | 2022-11-09 | 2022-12-30 | 上海太洋科技有限公司 | Preparation method of optical-grade aluminum dihydrogen phosphate |
| CN116425131A (en) * | 2022-12-30 | 2023-07-14 | 贵州芭田生态工程有限公司 | Method for removing metal impurities simultaneously by removing nitric acid |
Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4330516A (en) * | 1979-11-20 | 1982-05-18 | Rhone-Poulenc Industries | Decolorization and purification of crude wet-process phosphoric acid |
| US6007848A (en) * | 1994-09-23 | 1999-12-28 | Cultor Ltd. | Use of 1,4-anhydroglucitol/galactitol in low calorie food products, and a method of preparing 1,4-anhydro-dl-galactitol |
| CN1310153A (en) * | 2000-02-21 | 2001-08-29 | 四川大学 | Nitrophosphate fertilizer producing process eliminating calcium through direct freezing crystallization with low backpressure supersonic nozzle |
| CN1769163A (en) * | 2005-09-19 | 2006-05-10 | 绵阳高新区精微新材料有限公司 | Method for preparing technical grade phosphoric acid, foodstuff grade phosphoric acid and phosphate using wet method and thin phosphoric acid |
| CN101857216A (en) * | 2010-06-29 | 2010-10-13 | 贵州川恒化工有限责任公司 | Method for extracting and purifying wet-process phosphorous acid to produce industrial-grade phosphorous acid |
| CN102584386A (en) * | 2012-01-16 | 2012-07-18 | 瓮福（集团）有限责任公司 | Method for producing nitric phosphate fertilizer at low temperature under vacuum through concentrated crystallization and calcium removal as well asdevice |
| CN102718200A (en) * | 2012-07-10 | 2012-10-10 | 中海石油化学股份有限公司 | Method for preparing industrial-grade phosphoric acid by decomposing mid-low-grade phosphorite with nitric acid |
| CN103303886A (en) * | 2013-06-28 | 2013-09-18 | 山东鲁北企业集团总公司 | Novel method for producing industrial phosphoric acid by purification with wet process phosphoric acid |
| CN106241840A (en) * | 2016-09-08 | 2016-12-21 | 甘肃立焘新能源科技发展有限公司 | The preparation method of a kind of lithium hexafluoro phosphate and preparation system |
-
2022
- 2022-01-29 CN CN202210111826.XA patent/CN114436228A/en active Pending
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4330516A (en) * | 1979-11-20 | 1982-05-18 | Rhone-Poulenc Industries | Decolorization and purification of crude wet-process phosphoric acid |
| US6007848A (en) * | 1994-09-23 | 1999-12-28 | Cultor Ltd. | Use of 1,4-anhydroglucitol/galactitol in low calorie food products, and a method of preparing 1,4-anhydro-dl-galactitol |
| CN1310153A (en) * | 2000-02-21 | 2001-08-29 | 四川大学 | Nitrophosphate fertilizer producing process eliminating calcium through direct freezing crystallization with low backpressure supersonic nozzle |
| CN1769163A (en) * | 2005-09-19 | 2006-05-10 | 绵阳高新区精微新材料有限公司 | Method for preparing technical grade phosphoric acid, foodstuff grade phosphoric acid and phosphate using wet method and thin phosphoric acid |
| CN101857216A (en) * | 2010-06-29 | 2010-10-13 | 贵州川恒化工有限责任公司 | Method for extracting and purifying wet-process phosphorous acid to produce industrial-grade phosphorous acid |
| CN102584386A (en) * | 2012-01-16 | 2012-07-18 | 瓮福（集团）有限责任公司 | Method for producing nitric phosphate fertilizer at low temperature under vacuum through concentrated crystallization and calcium removal as well asdevice |
| CN102718200A (en) * | 2012-07-10 | 2012-10-10 | 中海石油化学股份有限公司 | Method for preparing industrial-grade phosphoric acid by decomposing mid-low-grade phosphorite with nitric acid |
| CN103303886A (en) * | 2013-06-28 | 2013-09-18 | 山东鲁北企业集团总公司 | Novel method for producing industrial phosphoric acid by purification with wet process phosphoric acid |
| CN106241840A (en) * | 2016-09-08 | 2016-12-21 | 甘肃立焘新能源科技发展有限公司 | The preparation method of a kind of lithium hexafluoro phosphate and preparation system |
Non-Patent Citations (1)
| Title |
|---|
| 于占江: "《国家示范性专业重点规划教材 摩擦材料生产工艺》", 30 January 2018, 天津大学出版社 * |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115535982A (en) * | 2022-11-09 | 2022-12-30 | 上海太洋科技有限公司 | Preparation method of optical-grade aluminum dihydrogen phosphate |
| CN116425131A (en) * | 2022-12-30 | 2023-07-14 | 贵州芭田生态工程有限公司 | Method for removing metal impurities simultaneously by removing nitric acid |
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