CN117920100A - High-purity ferric nitrate production system and preparation method - Google Patents
High-purity ferric nitrate production system and preparation method Download PDFInfo
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- CN117920100A CN117920100A CN202410325104.3A CN202410325104A CN117920100A CN 117920100 A CN117920100 A CN 117920100A CN 202410325104 A CN202410325104 A CN 202410325104A CN 117920100 A CN117920100 A CN 117920100A
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- reaction kettle
- crystallization
- ferric nitrate
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- VCJMYUPGQJHHFU-UHFFFAOYSA-N iron(3+);trinitrate Chemical compound [Fe+3].[O-][N+]([O-])=O.[O-][N+]([O-])=O.[O-][N+]([O-])=O VCJMYUPGQJHHFU-UHFFFAOYSA-N 0.000 title claims abstract description 148
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 44
- 238000002360 preparation method Methods 0.000 title abstract description 14
- 238000002425 crystallisation Methods 0.000 claims abstract description 119
- 230000008025 crystallization Effects 0.000 claims abstract description 117
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 79
- 238000006243 chemical reaction Methods 0.000 claims abstract description 74
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims abstract description 55
- 229910017604 nitric acid Inorganic materials 0.000 claims abstract description 41
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 claims abstract description 40
- 238000003860 storage Methods 0.000 claims abstract description 38
- 230000000536 complexating effect Effects 0.000 claims abstract description 28
- 229910052742 iron Inorganic materials 0.000 claims abstract description 28
- 238000006386 neutralization reaction Methods 0.000 claims abstract description 24
- 238000000746 purification Methods 0.000 claims abstract description 14
- 238000005406 washing Methods 0.000 claims description 69
- 239000012535 impurity Substances 0.000 claims description 39
- 239000000706 filtrate Substances 0.000 claims description 30
- 239000000047 product Substances 0.000 claims description 30
- 239000002994 raw material Substances 0.000 claims description 26
- 239000002244 precipitate Substances 0.000 claims description 21
- 238000010668 complexation reaction Methods 0.000 claims description 20
- 238000011084 recovery Methods 0.000 claims description 19
- 238000001914 filtration Methods 0.000 claims description 18
- 239000007788 liquid Substances 0.000 claims description 17
- 229910000013 Ammonium bicarbonate Inorganic materials 0.000 claims description 16
- 239000001099 ammonium carbonate Substances 0.000 claims description 16
- ATRRKUHOCOJYRX-UHFFFAOYSA-N Ammonium bicarbonate Chemical compound [NH4+].OC([O-])=O ATRRKUHOCOJYRX-UHFFFAOYSA-N 0.000 claims description 15
- 235000012538 ammonium bicarbonate Nutrition 0.000 claims description 15
- 238000003756 stirring Methods 0.000 claims description 14
- 238000001816 cooling Methods 0.000 claims description 12
- 239000013078 crystal Substances 0.000 claims description 12
- 239000007787 solid Substances 0.000 claims description 12
- 238000010521 absorption reaction Methods 0.000 claims description 11
- 230000007246 mechanism Effects 0.000 claims description 11
- 238000000034 method Methods 0.000 claims description 11
- SZQUEWJRBJDHSM-UHFFFAOYSA-N iron(3+);trinitrate;nonahydrate Chemical compound O.O.O.O.O.O.O.O.O.[Fe+3].[O-][N+]([O-])=O.[O-][N+]([O-])=O.[O-][N+]([O-])=O SZQUEWJRBJDHSM-UHFFFAOYSA-N 0.000 claims description 8
- 239000003795 chemical substances by application Substances 0.000 claims description 6
- 230000003472 neutralizing effect Effects 0.000 claims description 6
- 239000000110 cooling liquid Substances 0.000 claims description 3
- 238000005265 energy consumption Methods 0.000 abstract description 3
- MVFCKEFYUDZOCX-UHFFFAOYSA-N iron(2+);dinitrate Chemical compound [Fe+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O MVFCKEFYUDZOCX-UHFFFAOYSA-N 0.000 abstract description 3
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N Iron oxide Chemical compound [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 description 14
- 238000010586 diagram Methods 0.000 description 8
- 235000013980 iron oxide Nutrition 0.000 description 8
- 229910021654 trace metal Inorganic materials 0.000 description 8
- 230000008569 process Effects 0.000 description 6
- 239000012265 solid product Substances 0.000 description 6
- 229910052751 metal Inorganic materials 0.000 description 5
- 230000001965 increasing effect Effects 0.000 description 4
- 239000002184 metal Substances 0.000 description 4
- 239000008139 complexing agent Substances 0.000 description 3
- 229910052802 copper Inorganic materials 0.000 description 3
- 230000000694 effects Effects 0.000 description 2
- 239000012528 membrane Substances 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000001556 precipitation Methods 0.000 description 2
- 230000001737 promoting effect Effects 0.000 description 2
- 230000000630 rising effect Effects 0.000 description 2
- CWYNVVGOOAEACU-UHFFFAOYSA-N Fe2+ Chemical compound [Fe+2] CWYNVVGOOAEACU-UHFFFAOYSA-N 0.000 description 1
- 229910002588 FeOOH Inorganic materials 0.000 description 1
- 229910002651 NO3 Inorganic materials 0.000 description 1
- NHNBFGGVMKEFGY-UHFFFAOYSA-N Nitrate Chemical compound [O-][N+]([O-])=O NHNBFGGVMKEFGY-UHFFFAOYSA-N 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 239000007795 chemical reaction product Substances 0.000 description 1
- 239000002826 coolant Substances 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 238000007865 diluting Methods 0.000 description 1
- 238000007599 discharging Methods 0.000 description 1
- 230000002708 enhancing effect Effects 0.000 description 1
- 229960004887 ferric hydroxide Drugs 0.000 description 1
- 229910052598 goethite Inorganic materials 0.000 description 1
- AEIXRCIKZIZYPM-UHFFFAOYSA-M hydroxy(oxo)iron Chemical compound [O][Fe]O AEIXRCIKZIZYPM-UHFFFAOYSA-M 0.000 description 1
- 230000008676 import Effects 0.000 description 1
- 230000006698 induction Effects 0.000 description 1
- -1 iron ions form iron oxides Chemical class 0.000 description 1
- VBMVTYDPPZVILR-UHFFFAOYSA-N iron(2+);oxygen(2-) Chemical class [O-2].[Fe+2] VBMVTYDPPZVILR-UHFFFAOYSA-N 0.000 description 1
- IEECXTSVVFWGSE-UHFFFAOYSA-M iron(3+);oxygen(2-);hydroxide Chemical compound [OH-].[O-2].[Fe+3] IEECXTSVVFWGSE-UHFFFAOYSA-M 0.000 description 1
- 229910021645 metal ion Inorganic materials 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 238000012544 monitoring process Methods 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 238000010517 secondary reaction Methods 0.000 description 1
- 239000007921 spray Substances 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 229910021655 trace metal ion Inorganic materials 0.000 description 1
- 230000001960 triggered effect Effects 0.000 description 1
Landscapes
- Inorganic Compounds Of Heavy Metals (AREA)
Abstract
The invention relates to the technical field of iron nitrate preparation, and discloses a high-purity iron nitrate production system and a preparation method. The high-purity ferric nitrate production system comprises a primary reaction kettle, a neutralization reaction kettle, a complexing reaction kettle, a primary crystallization kettle and a secondary crystallization kettle which are sequentially arranged; the primary reaction kettle is used for reacting iron with dilute nitric acid to obtain ferric nitrate solution; the device also comprises a nitric acid storage tank which is respectively connected with the primary reaction kettle, the complexing reaction kettle and the primary crystallization kettle through nitric acid conveying pipelines; the device also comprises a pure water pipeline which is respectively connected with the primary reaction kettle, the complexing reaction kettle, the primary crystallization kettle and the secondary crystallization kettle. The high-purity ferric nitrate production system adopts a plurality of purification processes, so that the product has the advantages of high purity, low energy consumption, high yield and less pollution in the preparation process.
Description
Technical Field
The invention relates to the technical field of ferric nitrate preparation, in particular to a high-purity ferric nitrate production system and a preparation method.
Background
Along with the continuous rising demand for products such as high-end equipment and parts, the demand for raw materials such as high-purity ferric nitrate for high-end equipment and parts manufacturers is also continuously rising at present. At present, the purity of the domestic ferric nitrate solid products is generally only 99 percent, and the ferric nitrate solid products with higher purity (such as the content of each impurity is required to be respectively lower than 10 mug/g) are mainly dependent on foreign import at present, so that the price is higher. The main reason for the low purity of the ferric nitrate solid product is that the iron raw material contains various trace impurities, such as Cu, zn, ni, mn, etc., and the currently known low-cost high-yield ferric nitrate preparation process cannot effectively remove the trace impurities, so that the yield of the high-purity ferric nitrate solid product is low and the production cost is high.
Disclosure of Invention
In view of the shortcomings of the prior art, the invention aims to provide a high-purity ferric nitrate production system and a preparation method, and aims to solve the technical problems of low yield and high production cost of a high-purity ferric nitrate solid product in the prior art.
In order to achieve the above purpose, the invention adopts the following technical scheme:
the first aspect of the invention provides a high-purity ferric nitrate production system, which comprises a primary reaction kettle, a neutralization reaction kettle, a complexing reaction kettle, a primary crystallization kettle and a secondary crystallization kettle which are sequentially arranged; the primary reaction kettle is used for reacting iron with dilute nitric acid to obtain ferric nitrate solution; the device also comprises a nitric acid storage tank which is respectively connected with the primary reaction kettle, the complexing reaction kettle and the primary crystallization kettle through nitric acid conveying pipelines; the device also comprises a pure water pipeline which is respectively connected with the primary reaction kettle, the complexing reaction kettle, the primary crystallization kettle and the secondary crystallization kettle.
The high-purity ferric nitrate production system comprises a primary reaction kettle, a secondary reaction kettle and a high-purity ferric nitrate production system, wherein the primary reaction kettle comprises a first kettle body and an iron raw material adding device arranged on the first kettle body; the iron raw material adding device comprises a groove body and a hopper, wherein the groove body is obliquely arranged, and the hopper is arranged on the groove body; a vibrator is also arranged on the groove body; the discharge end of the tank body is arranged on the feed inlet of the first kettle body.
The high-purity ferric nitrate production system is characterized in that a feeding control mechanism is arranged on the first kettle body; the feeding control mechanism comprises a connecting shaft, a baffle and a balancing weight; a feeding pipe is arranged on the feeding hole; the connecting shaft is movably connected with one side of the top end of the feeding pipe; the baffle is fixedly connected with the connecting shaft and is positioned in the feeding pipe; the balancing weight is fixedly connected with the connecting shaft and is positioned outside the feeding pipe; the balancing weight and the baffle are respectively positioned at two sides of the connecting shaft; the feeding control mechanism further comprises an infrared sensing device and a trigger piece; the triggering piece is fixed on the connecting shaft and is used for triggering the infrared sensing device; the high-purity ferric nitrate production system also comprises a control device, and the infrared sensing device and the vibrator are respectively and electrically connected with the control device.
The high-purity ferric nitrate production system further comprises a tail gas purification subsystem, wherein the inlet end of the tail gas purification subsystem is connected with the top of the first kettle body through a tail gas pipeline; and an absorption liquid discharge end of the tail gas purification subsystem is connected with the top of the first kettle body through an absorption liquid pipeline.
The high-purity ferric nitrate production system is characterized in that a first pH meter is arranged in the neutralization reaction kettle; the bottom of the neutralization reaction kettle is provided with a first discharge port; the first discharge port is connected with the feed end of the complexing reaction kettle; the first discharge outlet is also connected with a solid discharge pipeline.
The high-purity ferric nitrate production system comprises a complexing reaction kettle, a first stirring device, a first jacket and a second pH meter, wherein the complexing reaction kettle comprises a second kettle body; the first jacket is connected with a steam pipeline; the bottom of the complex reaction kettle is provided with a second discharge port; the second discharge port is connected with the feed end of the primary crystallization kettle; the second discharge port is also connected with an impurity filtrate discharge pipeline.
The high-purity ferric nitrate production system comprises a first crystallization kettle, a second crystallization kettle and a second stirring device, wherein the first crystallization kettle comprises a third kettle body, and the second stirring device and a second jacket are arranged on the third kettle body, and the second jacket is connected with a cooling liquid pipeline; the discharge end of the primary crystallization kettle is connected with the feed end of the secondary crystallization kettle.
The high-purity ferric nitrate production system further comprises a crystallization filtrate storage tank; the bottom outlets of the primary crystallization kettle and the secondary crystallization kettle are also respectively connected with a crystallization filtrate storage tank through filtrate recovery pipelines, and the outlet end of the crystallization filtrate storage tank is connected with the complexation reaction kettle through a filtrate adding pipeline.
The high-purity ferric nitrate production system further comprises a washing water recovery subsystem, wherein the washing water recovery subsystem comprises a primary washing water storage tank and a secondary washing water storage tank; the bottom outlet of the primary crystallization kettle is also connected with a primary washing water storage tank through a primary washing water recovery pipeline, and the liquid outlet of the primary washing water storage tank is connected with the complexing reaction kettle through a primary washing water adding pipeline; the bottom outlet of the secondary crystallization kettle is also connected with a secondary washing water storage tank through a secondary washing water recovery pipeline, and the liquid outlet of the secondary washing water storage tank is connected with the primary crystallization kettle through a secondary washing water adding pipeline.
The second aspect of the present invention provides a method for preparing high-purity ferric nitrate, which adopts the high-purity ferric nitrate production system, comprising the following steps:
adding dilute nitric acid and excessive iron raw materials into a primary reaction kettle, and fully reacting to obtain a first solution;
Transferring the first solution to a neutralization reaction kettle, adding a neutralizing agent ammonium bicarbonate, filtering to obtain a second solution and a first precipitate, and controlling the pH value to be 3.0-3.5;
transferring the second solution to a complexation reaction kettle, introducing clean air while stirring, adding ammonium bicarbonate to carry out complexation reaction, controlling the pH value to be 3.5-5.0, reacting for 280-300 minutes at the temperature of 95-99 ℃, filtering to obtain a second precipitate, and washing the second precipitate by pure water; adding nitric acid solution to dissolve the washed second precipitate to obtain a third solution;
Transferring the third solution to a primary crystallization kettle, gradually cooling the temperature in the kettle to-5 ℃ within 12 hours to obtain crystals, filtering to obtain a first crystallization product, washing the first crystallization product by pure water, and adding dilute nitric acid to dissolve the washed first crystallization product to obtain a fourth solution;
transferring the fourth solution to a secondary crystallization kettle, gradually cooling the temperature in the kettle to-5 ℃ within 12 hours to obtain crystals, filtering to obtain a second crystallization product, washing the second crystallization product by pure water, and obtaining the second crystallization product after washing as high-purity ferric nitrate nonahydrate solid.
The beneficial effects are that: the invention provides a high-purity ferric nitrate production system, which is characterized in that trace impurities in a primary product are removed through a multi-stage purification and impurity removal process by using a primary reaction kettle, a neutralization reaction kettle, a complexing reaction kettle, a primary crystallization kettle and a secondary crystallization kettle in a combined way, so that high-yield high-purity ferric nitrate with the impurity content lower than 10 mug/g can be obtained, the preparation requirements of high-end parts and equipment can be met, and the system is low in energy consumption and less in pollution in operation.
The second aspect of the invention provides a preparation method of high-purity ferric nitrate, which sequentially adopts ammonium bicarbonate to perform neutralization reaction and complexation reaction, and adopts a multistage crystallization method to purify the product, so that new impurities are effectively prevented from being introduced in the impurity removal process, the purity of ferric nitrate solid is improved, and high-purity ferric nitrate crystals are obtained.
Drawings
Fig. 1 is a schematic diagram of a high-purity ferric nitrate production system according to the present invention.
FIG. 2 is a schematic structural diagram of a primary reaction vessel in one embodiment.
FIG. 3 is a schematic structural diagram of a primary reaction vessel in another embodiment.
Fig. 4 is an enlarged view of fig. 3 at a.
Fig. 5 is a schematic diagram of the connection relationship between the tail gas purification subsystem and the primary reaction kettle.
FIG. 6 is a schematic structural diagram of a neutralization reaction vessel.
FIG. 7 is a schematic structural diagram of a complex reaction vessel.
FIG. 8 is a schematic structural diagram of a primary crystallization kettle.
FIG. 9 is a schematic diagram of a high purity ferric nitrate production system.
Description of main reference numerals: 1-primary reaction kettle, 2-neutralization reaction kettle, 3-complexation reaction kettle, 4-primary crystallization kettle, 5-secondary crystallization kettle, 6-nitric acid conveying pipeline, 7-pure water pipeline, 8-ammonium bicarbonate adding pipeline, 110-primary kettle body, 120-tank body, 130-hopper, 140-vibrator, 150-feeding control mechanism, 151-connecting shaft, 152-baffle, 153-balancing weight, 160-feeding pipe, 154-infrared induction device, 155-trigger, 9-tail gas purification subsystem, 910-tail gas pipeline, 920-absorption liquid pipeline, 210-primary pH meter, 220-solid discharge pipeline, 310-secondary crystallization kettle body, 320-primary stirring device, 330-primary jacket, 340-secondary pH meter, 350-steam pipeline, 360-impurity filtrate discharge pipeline, 410-third kettle body, 420-secondary stirring device, 430-secondary jacket, 440-cooling liquid pipeline, 10-crystallization filtrate storage tank, 101-filtrate recovery pipeline, 102-filtrate adding pipeline, 11-primary storage tank, 111-primary storage tank, 220-secondary washing water recovery pipeline, 121-secondary washing water recovery pipeline, 12-secondary washing water recovery pipeline, and 122-washing water recovery pipeline.
Detailed Description
The invention provides a high-purity ferric nitrate production system and a preparation method thereof, which are used for making the purposes, technical schemes and effects of the invention clearer and more definite, and the invention is further described in detail below by referring to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the invention.
In the description of the present invention, it should be understood that the terms "upper," "lower," "left," "right," and the like indicate an orientation or a positional relationship based on that shown in the drawings, and are merely for convenience of description and for simplifying the description, and do not indicate or imply that the apparatus or element in question must have a specific orientation, as well as a specific orientation configuration and operation, and thus should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature. In the description of the present invention, unless otherwise indicated, the meaning of "a plurality" is two or more.
Referring to fig. 1, a first aspect of the present invention provides a high-purity ferric nitrate production system, which includes a primary reaction kettle 1, a neutralization reaction kettle 2, a complexing reaction kettle 3, a primary crystallization kettle 4 and a secondary crystallization kettle 5, which are sequentially arranged; the primary reaction kettle 1 is used for reacting iron with dilute nitric acid to obtain ferric nitrate solution; the device also comprises a nitric acid storage tank which is respectively connected with the primary reaction kettle 1, the complexing reaction kettle 3 and the primary crystallization kettle 4 through nitric acid conveying pipelines 6; the device also comprises a pure water pipeline 7, wherein the pure water pipeline 7 is respectively connected with the primary reaction kettle 1, the complexation reaction kettle 3, the primary crystallization kettle 4 and the secondary crystallization kettle 5.
Specifically, the nitric acid conveying pipeline 6 is used for adding concentrated nitric acid, the pure water pipeline 7 is used for providing pure water in the primary reaction kettle 1 to prepare the concentrated nitric acid into dilute nitric acid, and the dilute nitric acid is further reacted with an iron raw material to obtain an iron nitrate solution;
The ferric nitrate solution then enters a neutralization reaction kettle 2, and partial impurity metal elements form precipitates through the neutralization reaction;
The ferric nitrate solution subjected to preliminary impurity removal enters a complexing reaction kettle 3, wherein the complexing reaction kettle 3 is specifically connected with an alkaline complexing agent adding pipeline, the ferric nitrate solution forms iron oxide precipitation through an alkaline complexing agent, the other trace metal impurities form a complex, the complex exists in the solution, impurity filtrate is discharged, and then the second impurity removal is completed after pure water washing; then adding concentrated nitric acid and pure water into the complex reaction kettle 3 to dissolve iron oxide, and obtaining ferric nitrate solution again;
The ferric nitrate solution is then conveyed to a primary crystallization kettle 4 for cooling crystallization, and in the crystallization process, part of trace metal impurities exist in the solution, and after the solution is separated from the crystallization by filtration, part of trace metal impurities are removed, so that the purity of the ferric nitrate is further improved; washing the ferric nitrate crystal by pure water, and dissolving by dilute nitric acid again to obtain ferric nitrate solution;
And conveying the ferric nitrate solution to a secondary crystallization kettle 5 for cooling crystallization again, and filtering and washing with pure water to obtain the high-purity ferric nitrate. The high-purity ferric nitrate production system provided by the invention processes the produced ferric nitrate through four impurity removal processes, and finally the content of each metal impurity can be controlled below 10 mug/g.
Preferably, the neutralization reaction kettle 2 and the complexation reaction kettle 3 are both connected with an ammonium bicarbonate adding pipeline 8, and the ammonium bicarbonate is used as a neutralizing agent and an alkaline complexing agent, and specifically, the ammonium bicarbonate is a solid particle raw material.
Specifically, the above-mentioned nitric acid conveying pipeline 6 respectively with the first-stage reaction kettle 1, complex reaction kettle 3 and the linkage segment of first-stage crystallization kettle 4, and pure water pipeline 7 respectively with first-stage reaction kettle 1, complex reaction kettle 3, first-stage crystallization kettle 4 and the linkage segment of second-stage crystallization kettle 5 respectively be provided with liquid such as manometer, flowmeter, solenoid valve, delivery pump add controlgear and liquid and add supervisory equipment, high-purity ferric nitrate production system still is provided with controlgear and above consumer and supervisory equipment connection to ensure that the addition of all kinds of liquids is accurate.
Referring to fig. 2, in one embodiment, the primary reaction kettle 1 includes a first kettle body 110 and an iron raw material adding device disposed on the first kettle body 110; the iron raw material adding device comprises a groove body 120 which is obliquely arranged and a hopper 130 which is arranged on the groove body 120; the tank 120 is further provided with a vibrator 140; the discharge end of the tank 120 is disposed on the feed inlet of the first tank 110.
In this embodiment, the vibrator 140 may shake the tank 120 to make the iron raw material on the tank 120 drop into the first kettle 110, so that no iron raw material is required to be added manually.
Referring to fig. 3 and 4, the first kettle body 110 is provided with a feeding control mechanism 150; the feeding control mechanism 150 comprises a connecting shaft 151, a baffle 152 and a balancing weight 153; a feed pipe 160 is arranged on the feed port; the connecting shaft 151 is movably connected with one side of the top end of the feeding pipe 160; the baffle 152 is fixedly connected with the connecting shaft 151 and is positioned in the feeding pipe 160; the balancing weight 153 is fixedly connected with the connecting shaft 151 and is positioned outside the feeding pipe 160; the balancing weight 153 and the baffle 152 are respectively positioned at two sides of the connecting shaft 151; the feed control mechanism 150 further includes an infrared sensing device 154 and a trigger 155; the triggering element 155 is fixed on the connecting shaft 151 and is used for triggering the infrared sensing device 154; the high-purity ferric nitrate production system further comprises a control device, and the infrared sensing device 154 and the vibrator 140 are respectively and electrically connected with the control device.
In this embodiment, the feeding control mechanism 150 is configured to activate the vibrator 140 at regular time, so that a fixed amount of iron raw material is automatically added into the first tank 110. The specific operation principle is as follows: when iron raw materials fall from the tank body 120, firstly fall on the baffle 152 and cannot fall into the first kettle body 110 temporarily, when the weight of the iron raw materials on the baffle 152 overcomes the balancing weight 153, the baffle 152 is inclined downwards, the feeding pipe 160 is opened, the iron raw materials enter the first kettle body 110 from the feeding pipe 160, when the baffle 152 rotates downwards, the triggering piece 155 on the connecting shaft 151 is driven to displace simultaneously, the infrared sensing device 154 is triggered to start, signals generated by the infrared sensing device 154 are transmitted to the control device, the control device controls the vibrator 140 to stop running, after the iron raw materials on the baffle 152 are reduced, the baffle 152 and the triggering piece 155 reset under the action of the balancing weight 153, the control device can automatically send out instructions after setting for 10 minutes to enable the vibrator 140 to run again, and therefore a certain amount of iron raw materials can be automatically added at regular time.
Referring to fig. 5, in one embodiment, the high-purity ferric nitrate production system further includes an exhaust gas purification subsystem 9, where an inlet end of the exhaust gas purification subsystem 9 is connected to the top of the first kettle 110 through an exhaust gas pipe 910; the absorption liquid discharge end of the exhaust gas purifying subsystem 9 is connected with the top of the first kettle body 110 through an absorption liquid pipeline 920. Preferably, the tail gas purification subsystem 9 can adopt a multi-stage water spray absorption tower to absorb tail gas, the main component in the tail gas is NO, the rest is a small amount of NO 2, and the absorption liquid formed after water absorption can be directly recycled to the diluted primary reaction kettle 1 for diluting concentrated nitric acid.
Referring to fig. 6, in one embodiment, a first pH meter 210 is disposed in the neutralization reaction kettle 2; the bottom of the neutralization reaction kettle 2 is provided with a first discharge port; the first discharge port is connected with the feed end of the complexation reaction kettle 3; the first discharge opening is also connected with a solids discharge conduit 220. The progress of the neutralization reaction can be accurately monitored by the first pH meter 210, avoiding excessive addition of neutralizing agent. Specifically, the first pH meter 210 is electrically connected to a control device. After the neutralization reaction, the solution is transported to the complexing reaction vessel 3 through a pipe, and the remaining solid impurities are discharged through a solid discharge pipe 220.
Referring to fig. 7, in one embodiment, the complex reaction kettle 3 includes a second kettle body 310, a first stirring device 320, a first jacket 330 and a second pH meter 340 disposed on the second kettle body 310; the first jacket 330 is connected with a steam pipe 350; the bottom of the complex reaction kettle 3 is provided with a second discharge port; the second discharge port is connected with the feed end of the primary crystallization kettle 4; the second discharge port is also connected with an impurity filtrate discharge pipe 360. The first stirring device 320 is used for increasing fluidity, promoting heat transfer and promoting the progress of the complexation reaction, and the first jacket 330 is used for increasing the temperature in the second kettle body 310, thereby improving the solubility of the complex and enhancing the impurity removal effect of the complexation reaction. The second pH meter 340 is used for detecting the pH of the solution in the kettle and monitoring the progress of the complexation reaction. Specifically, the second pH meter 340 is electrically connected to a control device.
Specifically, the complexing reaction kettle 3 is also connected with a purified air pipeline for introducing purified air during the complexing reaction. The complex reaction kettle 3 is also connected with a tail gas pipeline for discharging tail gas.
Referring to fig. 8, in one embodiment, the primary crystallization kettle 4 includes a third kettle body 410, and a second stirring device 420 and a second jacket 430 disposed on the third kettle body 410, where the second jacket 430 is connected with a coolant pipe 440; the discharge end of the primary crystallization kettle 4 is connected with the feed end of the secondary crystallization kettle 5. The second jacket 430 is used for cooling the third tank 410.
In one embodiment, the secondary crystallization kettle 5 has the same structure as the primary crystallization kettle 4.
Referring to fig. 9, in one embodiment, the high purity ferric nitrate production system further comprises a crystallization filtrate storage tank 10; the bottom outlets of the primary crystallization kettle 4 and the secondary crystallization kettle 5 are also respectively connected with a crystallization filtrate storage tank 10 through a filtrate recovery pipeline 101, and the outlet end of the crystallization filtrate storage tank 10 is connected with the complexation reaction kettle 3 through a filtrate adding pipeline 102.
In the crystallization process, the impurity content of the product is low, so that the impurity content of the filtrate obtained after crystallization is trace, the filtrate can be reused, and when the filtrate is used, part of the recovered filtrate can be taken to be used together with new concentrated nitric acid for dissolving the iron oxide.
In this embodiment, the high-purity ferric nitrate production system further comprises a washing water recovery subsystem, wherein the washing water recovery subsystem comprises a primary washing water storage tank 11 and a secondary washing water storage tank 12; the bottom outlet of the primary crystallization kettle 4 is also connected with a primary washing water storage tank 11 through a primary washing water recovery pipeline 111, and the liquid outlet of the primary washing water storage tank 11 is connected with the complexation reaction kettle 3 through a primary washing water adding pipeline 112; the bottom outlet of the secondary crystallization kettle 5 is also connected with a secondary washing water storage tank 12 through a secondary washing water recovery pipeline 121, and the liquid outlet of the secondary washing water storage tank 12 is connected with the primary crystallization kettle 4 through a secondary washing water adding pipeline 122.
Specifically, after each purification, the impurities of the product are further reduced. The impurity content of the primary washing water obtained after the primary crystallized crystals are washed is lower than the impurity content of the iron oxide in the complexing reaction kettle 3, so that the primary washing water can be used for washing the iron oxide in the complexing reaction kettle 3, and during washing, the primary washing water in the primary washing water storage tank 11 is firstly adopted and then pure water is used for washing, so that the consumption of the pure water is reduced.
Similarly, the secondary washing water obtained after washing the crystals of the secondary crystallization can also be used for washing the crystals of the primary crystallization, thereby reducing the amount of pure water used.
Preferably, in one embodiment, a membrane filter is further connected to the downstream of the primary washing water storage tank 11 and the secondary washing water storage tank 12, and the recovered washing water can be primarily purified by the membrane filter, so that the purity of the washing water is improved.
The second aspect of the invention provides a method for preparing high-purity ferric nitrate, which adopts the high-purity ferric nitrate production system, and comprises the following steps:
S001, adding dilute nitric acid and excessive iron raw materials into a primary reaction kettle 1, and fully reacting to obtain a first solution; in the reaction with dilute nitric acid, various trace metal impurities such as Cu, zn, ni, mn, cr, al, K, na, ca and the like in the iron raw material are dissolved; in the primary reaction kettle 1, the reaction product obtained when the iron raw material is excessive is mainly ferrous nitrate, and a small amount of ferric nitrate exists;
S002, transferring the first solution to a neutralization reaction kettle 2, adding a neutralizing agent ammonium bicarbonate, filtering to obtain a second solution and a first precipitate, and controlling the pH value to be 3.0-3.5; the pH of the solution is changed through the neutralization reaction, so that partial trace metal ions can form precipitates, and the aim of removing impurities is fulfilled;
specifically, the ammonium bicarbonate is high-purity ammonium bicarbonate so as to avoid introducing new impurities;
S003, transferring the second solution to a complexation reaction kettle 3, introducing clean air while stirring, adding ammonium bicarbonate to carry out complexation reaction, controlling the pH value to be 3.5-5.0, reacting for 280-300 minutes at 95-99 ℃, filtering to obtain a second precipitate, and washing the second precipitate with pure water; when ammonium bicarbonate is further added into the complexing reaction kettle 3, iron ions form iron oxides (the iron oxides comprise goethite FeOOH precipitates and a small amount of ferric hydroxide precipitates) to be precipitated, and a small amount of impurity metals such as Cu, zn, ni, mn and the like form complexes without precipitation, so that iron is separated from impurity metal ions capable of undergoing complexing reaction; adding nitric acid solution to dissolve the washed second precipitate to obtain a third solution; specifically, the concentrated nitric acid and the pure water adopted by the invention are high-purity raw materials, and after the nitric acid solution is added to react with the second precipitate, the total mass and the volume of the system are increased, and trace metal impurities contained in the system are diluted;
S004, transferring the third solution to a primary crystallization kettle 4, gradually cooling to-5 ℃ for crystallization within 12 hours, and removing part of trace metal impurities after the crystallization, wherein the trace metal impurities remain in the solution, and removing the solution after filtration, so that a first crystallization product (ferric nitrate nonahydrate) is obtained; washing the first crystallization product by pure water, and adding dilute nitric acid to dissolve the washed first crystallization product to obtain a fourth solution (ferric nitrate solution); after adding dilute nitric acid to dissolve the first crystal product, the total mass and volume of the system are increased, and trace metal impurities contained in the system are diluted again;
s005, transferring the fourth solution to a secondary crystallization kettle 5, gradually cooling to-5 ℃ for crystallization within 12 hours, filtering to obtain a second crystallization product (ferric nitrate nonahydrate), washing the second crystallization product by pure water, and obtaining the second crystallization product which is high-purity ferric nitrate nonahydrate solid after washing.
In one embodiment, after cooling crystallization kettle 4 and secondary crystallization kettle 5, further comprising collecting filtrate to crystallization filtrate storage tank 10, the filtrate may be used to form dilute nitric acid with new concentrated nitric acid for dissolving iron oxide.
Example 1
A preparation method of high-purity ferric nitrate comprises the following steps:
adding dilute nitric acid and excessive iron raw materials into a primary reaction kettle, and fully reacting to obtain a first solution;
transferring the first solution to a neutralization reaction kettle, adding a neutralizing agent ammonium bicarbonate, filtering to obtain a second solution and a first precipitate, and controlling the pH value to be 3.3-3.5 during the reaction;
transferring the second solution to a complexation reaction kettle, introducing clean air while stirring, adding ammonium bicarbonate to carry out complexation reaction, controlling the pH value to be 4.8-5.0 during the reaction, reacting for 290 minutes at 95 ℃, filtering to obtain a second precipitate, and washing the second precipitate by pure water; adding nitric acid solution to dissolve the washed second precipitate to obtain a third solution;
Transferring the third solution to a primary crystallization kettle, gradually cooling the temperature in the kettle to-5 ℃ within 12 hours to obtain crystals, filtering to obtain a first crystallization product, washing the first crystallization product by pure water, and adding dilute nitric acid to dissolve the washed first crystallization product to obtain a fourth solution;
transferring the fourth solution to a secondary crystallization kettle, gradually cooling the temperature in the kettle to-5 ℃ within 12 hours to obtain crystals, filtering to obtain a second crystallization product, washing the second crystallization product by pure water, and obtaining the second crystallization product after washing as high-purity ferric nitrate nonahydrate solid.
The high purity ferric nitrate nonahydrate solid product prepared in example 1 was tested for various metal impurity contents using WFX-220A atomic absorption, and the results are shown in the following table:
| Units: ng/g | |
| Mn | 2793.31 |
| Mg | 222.17 |
| Ni | 8610.21 |
| Ca | 1302.67 |
| Zn | 3892.65 |
| Cu | 2319.56 |
| Na | 645.98 |
| Cr | 454.88 |
| K | 25.78 |
As can be seen from the table, the metal content requirement of each impurity of the high-purity ferric nitrate nonahydrate prepared by the method is lower than 10 mug/g, the method accords with the raw material requirement of high-end equipment and parts, and the preparation method and the equipment provided by the invention have the advantages of high yield, low energy consumption and less pollution.
It will be understood that equivalents and modifications will occur to those skilled in the art in light of the present invention and their spirit, and all such modifications and substitutions are intended to be included within the scope of the present invention as defined in the following claims.
Claims (10)
1. The high-purity ferric nitrate production system is characterized by comprising a primary reaction kettle, a neutralization reaction kettle, a complexing reaction kettle, a primary crystallization kettle and a secondary crystallization kettle which are sequentially arranged; the primary reaction kettle is used for reacting iron with dilute nitric acid to obtain ferric nitrate solution; the device also comprises a nitric acid storage tank which is respectively connected with the primary reaction kettle, the complexing reaction kettle and the primary crystallization kettle through nitric acid conveying pipelines; the device also comprises a pure water pipeline which is respectively connected with the primary reaction kettle, the complexing reaction kettle, the primary crystallization kettle and the secondary crystallization kettle.
2. The high purity ferric nitrate production system of claim 1, wherein the primary reaction kettle comprises a first kettle body and an iron raw material adding device arranged on the first kettle body; the iron raw material adding device comprises a groove body and a hopper, wherein the groove body is obliquely arranged, and the hopper is arranged on the groove body; a vibrator is also arranged on the groove body; the discharge end of the tank body is arranged on the feed inlet of the first kettle body.
3. The high purity ferric nitrate production system of claim 2, wherein the first kettle body is provided with a feed control mechanism; the feeding control mechanism comprises a connecting shaft, a baffle and a balancing weight; a feeding pipe is arranged on the feeding hole; the connecting shaft is movably connected with one side of the top end of the feeding pipe; the baffle is fixedly connected with the connecting shaft and is positioned in the feeding pipe; the balancing weight is fixedly connected with the connecting shaft and is positioned outside the feeding pipe; the balancing weight and the baffle are respectively positioned at two sides of the connecting shaft;
The feeding control mechanism further comprises an infrared sensing device and a trigger piece; the triggering piece is fixed on the connecting shaft and is used for triggering the infrared sensing device;
The high-purity ferric nitrate production system also comprises a control device, and the infrared sensing device and the vibrator are respectively and electrically connected with the control device.
4. The high purity ferric nitrate production system of claim 2, further comprising a tail gas purification subsystem, wherein an inlet end of the tail gas purification subsystem is connected with the top of the first kettle body through a tail gas pipeline; and an absorption liquid discharge end of the tail gas purification subsystem is connected with the top of the first kettle body through an absorption liquid pipeline.
5. The high purity ferric nitrate production system of claim 1, wherein a first pH meter is disposed in the neutralization reaction kettle; the bottom of the neutralization reaction kettle is provided with a first discharge port; the first discharge port is connected with the feed end of the complexing reaction kettle; the first discharge outlet is also connected with a solid discharge pipeline.
6. The high-purity ferric nitrate production system according to claim 1, wherein the complexing reaction kettle comprises a second kettle body, and a first stirring device, a first jacket and a second pH meter arranged on the second kettle body; the first jacket is connected with a steam pipeline; the bottom of the complex reaction kettle is provided with a second discharge port; the second discharge port is connected with the feed end of the primary crystallization kettle; the second discharge port is also connected with an impurity filtrate discharge pipeline.
7. The high-purity ferric nitrate production system according to claim 1, wherein the primary crystallization kettle comprises a third kettle body, and a second stirring device and a second jacket which are arranged on the third kettle body, wherein the second jacket is connected with a cooling liquid pipeline; the discharge end of the primary crystallization kettle is connected with the feed end of the secondary crystallization kettle.
8. The high purity ferric nitrate production system of claim 7, further comprising a crystallization filtrate storage tank; the bottom outlets of the primary crystallization kettle and the secondary crystallization kettle are also respectively connected with a crystallization filtrate storage tank through filtrate recovery pipelines, and the outlet end of the crystallization filtrate storage tank is connected with the complexation reaction kettle through a filtrate adding pipeline.
9. The high purity ferric nitrate production system of claim 8, further comprising a wash water recovery subsystem comprising a primary wash water storage tank and a secondary wash water storage tank; the bottom outlet of the primary crystallization kettle is also connected with a primary washing water storage tank through a primary washing water recovery pipeline, and the liquid outlet of the primary washing water storage tank is connected with the complexing reaction kettle through a primary washing water adding pipeline; the bottom outlet of the secondary crystallization kettle is also connected with a secondary washing water storage tank through a secondary washing water recovery pipeline, and the liquid outlet of the secondary washing water storage tank is connected with the primary crystallization kettle through a secondary washing water adding pipeline.
10. A method for preparing high purity ferric nitrate, characterized by using the high purity ferric nitrate production system according to any one of claims 1-9, comprising the steps of:
adding dilute nitric acid and excessive iron raw materials into a primary reaction kettle, and fully reacting to obtain a first solution;
Transferring the first solution to a neutralization reaction kettle, adding a neutralizing agent ammonium bicarbonate, filtering to obtain a second solution and a first precipitate, and controlling the pH value to be 3.0-3.5;
transferring the second solution to a complexation reaction kettle, introducing clean air while stirring, adding ammonium bicarbonate to carry out complexation reaction, controlling the pH value to be 3.5-5.0, reacting for 280-300 minutes at the temperature of 95-99 ℃, filtering to obtain a second precipitate, and washing the second precipitate by pure water; adding nitric acid solution to dissolve the washed second precipitate to obtain a third solution;
Transferring the third solution to a primary crystallization kettle, gradually cooling the temperature in the kettle to-5 ℃ within 12 hours to obtain crystals, filtering to obtain a first crystallization product, washing the first crystallization product by pure water, and adding dilute nitric acid to dissolve the washed first crystallization product to obtain a fourth solution;
transferring the fourth solution to a secondary crystallization kettle, gradually cooling the temperature in the kettle to-5 ℃ within 12 hours to obtain crystals, filtering to obtain a second crystallization product, washing the second crystallization product by pure water, and obtaining the second crystallization product after washing as high-purity ferric nitrate nonahydrate solid.
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