CN117945450A - Production process of nano rare earth polishing solution - Google Patents

Production process of nano rare earth polishing solution Download PDF

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Publication number
CN117945450A
CN117945450A CN202410116854.XA CN202410116854A CN117945450A CN 117945450 A CN117945450 A CN 117945450A CN 202410116854 A CN202410116854 A CN 202410116854A CN 117945450 A CN117945450 A CN 117945450A
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tank
cerium nitrate
rare earth
materials
solution
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CN202410116854.XA
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Inventor
张文胜
陈二喜
***
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Baotou Lichen Technology Co ltd
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Baotou Lichen Technology Co ltd
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Abstract

The invention provides a production process of nano rare earth polishing solution, which comprises the specific steps of taking ultra-high purity cerium nitrate crystal as a raw material, dissolving and preparing by pure water to obtain high purity cerium nitrate feed liquid, taking hydrogen peroxide as an oxidant, taking ammonia water as a precipitator, reversely precipitating, heating at high temperature, washing, plate-frame filter pressing, flash evaporation and drying, oxidizing roasting and wet grinding to obtain the high purity nano polishing solution.

Description

Production process of nano rare earth polishing solution
Technical Field
The invention relates to the technical field of polishing solution processing technology, in particular to a production technology of nano rare earth polishing solution.
Background
The rare earth element is applied to polishing solution or polishing powder, the rare earth polishing solution has the characteristics of low hardness, less scratch, high polishing speed, high precision and the like, in the polishing process, the rare earth polishing solution mainly plays a role in forming a layer of film on the surface of a workpiece through chemical action, then the abrasive in the polishing solution removes the film through mechanical action, and finally the chemical mechanical polishing process is finished, and the existing rare earth polishing solution has complex preparation process and high cost.
Disclosure of Invention
Aiming at the defects of the prior art, the invention provides a production process of nano rare earth polishing solution, which solves the problems that the purity of the existing rare earth polishing solution preparation process is relatively low and damage is brought to electronic products such as grinding.
A production process of nano rare earth polishing solution comprises the following steps:
Step one, preparing cerium nitrate solution
Pumping quantitative pure water into a solution tank from a pure water storage tank through a pump, adding cerium nitrate crystals into the solution tank through a vacuum suction machine, stirring in the solution tank until the cerium nitrate crystals are completely dissolved to obtain high-purity cerium nitrate feed liquid, and pumping the high-purity cerium nitrate feed liquid into a storage tank through a centrifugal pump;
step two, oxidation reaction
Pumping the cerium nitrate solution prepared in the first step into a high-level metering tank through a centrifugal pump from a storage tank, quantitatively adding the cerium nitrate solution into the solution tank through the high-level metering tank, quantitatively adding hydrogen peroxide into the solution tank, mixing the hydrogen peroxide and the cerium nitrate solution in the storage tank to perform oxidation reaction, and pumping the cerium nitrate solution into the high-level metering tank through the centrifugal pump after the oxidation reaction is completed;
Step three, synthesis reaction
Pumping quantitative ammonia water into a reaction kettle from an ammonia water storage tank through a centrifugal pump, adding the reaction materials in the second step into the reaction kettle quantitatively, mixing the reaction materials in the reaction kettle to react, heating the materials in the reaction kettle by steam after the reaction of the materials is finished, and standing and cooling the materials after the heating is finished;
Step four, washing and filter pressing
Discharging the supernatant fluid of the materials in the reaction kettle in the third step to a wastewater receiving tank, adding pure water into the slurry for washing for 1-3 times, placing the slurry into the slurry receiving tank, pumping the slurry from the slurry receiving tank into a filter press for press filtration by a feed pump, enabling the wastewater pressed by the filter press to enter the wastewater receiving tank, and pumping the wastewater to a wastewater tank by a centrifugal pump;
step five, roasting and oxidizing
Conveying the filter cake generated in the step four to an electric kiln workshop through a forklift, roasting at a high temperature through an electric kiln, treating waste gas generated by roasting through a spraying system, discharging the waste gas through an exhaust pipe, roasting the filter cake at the high temperature to enable the filter cake to undergo an oxidation reaction, and oxidizing to obtain high-purity cerium oxide;
Step six, grinding
Then, carrying out wet grinding on the high-purity cerium oxide generated in the step five;
Seventh, filling
And (5) after wet grinding, filling the finished product into a high-purity nano polishing solution product.
In one embodiment of the invention, the materials in the reaction kettle are heated by steam in the third step to 95-120 ℃.
In one embodiment of the invention, in the fourth step, the filter cake is baked at a high temperature by an electric kiln, wherein the baking temperature is 600-800 ℃.
In one embodiment of the invention, the centrifugal pump is a fluoroplastic centrifugal pump.
In one embodiment of the invention, the waste gas generated in the third step and the fifth step is input into a spraying system for treatment and then is discharged.
In one embodiment of the invention, the wastewater generated in the fourth step and the spraying system is discharged into a four-effect evaporation processor for treatment, and the treated water is recycled.
In one embodiment of the invention, the materials in the reaction kettle are stirred while the reaction kettle is heated in the third step.
The invention provides a production process of a nano rare earth polishing solution, which has the following beneficial effects:
The preparation of the polishing solution comprises the steps of firstly preparing cerium nitrate solution, then carrying out oxidation reaction on the cerium nitrate solution, then carrying out synthesis reaction on materials obtained by oxidation, then washing and filter pressing the synthesized materials, roasting and oxidizing a filter cake, then carrying out wet grinding on the roasted materials, and finally filling a finished polishing solution product.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings that are needed in the embodiments will be briefly described below, it being understood that the following drawings only illustrate some examples of the present invention and therefore should not be considered as limiting the scope, and other related drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.
Fig. 1 is a flow chart of the production process of the present invention.
Detailed Description
For the purpose of making the objects, technical solutions and advantages of the embodiments of the present invention more apparent, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is apparent that the described embodiments are some embodiments of the present invention, but not all embodiments. All other embodiments, based on the embodiments of the invention, which are apparent to those of ordinary skill in the art without inventive faculty, are intended to be within the scope of the invention.
In the description of the present invention, unless explicitly specified and limited otherwise, the terms "mounted," "connected," "coupled," and the like are to be construed broadly and may be, for example, fixedly attached, detachably attached, or integrally attached; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present invention will be understood in specific cases by those of ordinary skill in the art.
In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings are merely for convenience in describing the present invention and simplifying the description, and do not indicate or imply that the apparatus or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present invention.
Examples
The high-purity nano polishing liquid product takes ultra-high-purity cerium nitrate crystals as raw materials, pure water is used for dissolution and blending to obtain high-purity cerium nitrate feed liquid, hydrogen peroxide is used as an oxidant, ammonia water is used as a precipitator, reverse precipitation is carried out, and the high-purity nano polishing liquid is obtained through high-temperature heating, washing, plate and frame filter pressing, flash evaporation drying, oxidizing roasting and wet grinding. The chemical reaction equation involved is as follows:
2Ce(NO3)3+3H2O2+6NH3·H2O→2Ce(OH)3OOH+6NH4NO3+2H2O
Ce(OH)3OOH→Ce(OH)4+1/2O2↑
Quality standard: polishing the SiO2 insulating layer on the integrated circuit chip by using CeO 2-based polishing solution, wherein the polishing speed is more than or equal to 100nm/min and the surface roughness Ra is less than or equal to 1nm under proper process conditions;
product parameters: the total concentration of harmful impurity ions in the CeO2 polishing solution reaches the sub-ppm level; ceO2 has narrow size distribution, the central value of the primary particle size is 100+/-30 nm, and the maximum particle size in the polishing solution is less than 300nm.
A production process of nano rare earth polishing solution comprises the following steps:
Step one, preparing cerium nitrate solution
Pumping quantitative pure water into a solution tank from a pure water storage tank through a pump, adding raw material cerium nitrate into the solution tank through a vacuum suction machine, utilizing the air pressure difference between vacuum and an environment space by the vacuum suction machine to form air flow in a pipeline to drive the raw material cerium nitrate to move, thereby completing the transportation of the raw material, wherein the annual usage amount of the raw material cerium nitrate is 108t, the pure water amount required for preparing a cerium nitrate solution is 612t/a, stirring in the solution tank until the raw material cerium nitrate is completely dissolved to obtain high-purity cerium nitrate feed liquid, pumping the high-purity cerium nitrate feed liquid into the solution tank through a fluoroplastic centrifugal pump, and waiting for entering the next oxidation synthesis reaction process;
step two, oxidation reaction
Pumping the high-purity cerium nitrate solution prepared in the first step into a high-level metering tank through a fluoroplastic centrifugal pump from a storage tank, quantitatively adding the high-level metering tank into a solution tank, quantitatively adding hydrogen peroxide into the solution tank (pumping the hydrogen peroxide into the high-level metering tank through the fluoroplastic centrifugal pump from a hydrogen peroxide storage tank), mixing the hydrogen peroxide and the cerium nitrate solution in the storage tank to perform oxidation reaction, and pumping the mixture into the high-level metering tank through the centrifugal pump after the oxidation reaction is finished; hydrogen peroxide: colorless transparent liquid with weak special smell, and is soluble in water, alcohol and ether, insoluble in benzene and petroleum ether. Melting point: -2 ℃ (anhydrous), boiling point: 158 ℃ (anhydrous), saturated vapor pressure 0.13
(15.3 ℃), Relative density (water=1): 1.46 (anhydrous) relative density (air=1): 3.5. hydrogen peroxide is not combustible, but can react with combustible materials to release a large amount of heat and oxygen to cause ignition explosion. The PH value of hydrogen peroxide is most stable at 3.5-4.5, is easy to decompose in alkaline solution, and can decompose when encountering strong light, especially when irradiated by wave rays. When heated above 100 ℃, rapid decomposition begins. It forms an explosive mixture with many organic substances, such as sugar, starch, alcohols, petroleum products, etc., and can explode under the action of impact, heat or electric spark. Hydrogen peroxide can be rapidly decomposed to cause explosion after contacting with a plurality of inorganic compounds or impurities, and a large amount of heat, oxygen and water vapor are emitted. Most heavy metals (such as iron, copper, silver, lead, mercury, zinc, cobalt, nickel, chromium, manganese, etc.) and their oxides and salts are active catalysts, and dust, soot, carbon powder, rust, etc. can also accelerate decomposition. Hydrogen peroxide at a concentration exceeding 74% can cause gas phase explosions in closed containers with appropriate ignition sources or temperatures. Inhalation of the product vapor or mist is strongly irritating to the respiratory tract. Direct eye contact with liquids can lead to irreversible loss and even blindness. Oral poisoning may occur as abdominal pain, chest pain, dyspnea, vomiting, chronokinesia and sensory disturbance, elevated body temperature, etc. Individual cases present with vision impairment, epileptiform cramps, paresis, etc.
The chemical reaction equation involved in this process is as follows:
2Ce(NO3)3+3H2O2+4H2O→2Ce(OH)3OOH+6HNO3
Step three, synthesis reaction
The ammonia water contains NH 3·H2 O as main component, is aqueous ammonia solution, has molecular weight of 35, is colorless and transparent, and has pungent smell. Ammonia has a melting point of-77.773 ℃, a boiling point of-33.34 ℃ and a density of 0.91g/cm 3. Ammonia is easily dissolved in water and ethanol. Is volatile, has partial alkali permeability, and is prepared by introducing ammonia into water. Ammonia is toxic, has irritation and corrosiveness to eyes, nose and skin, can suffocate people, and has the maximum allowable concentration of 30mg/m 3 in air. Industrial ammonia water is an aqueous solution containing 25% -28% ammonia, and only a small part of ammonia molecules in the ammonia water react with water to form ammonia monohydrate, which is a weak base only existing in the ammonia water. The freezing point of ammonia water is related to the concentration of ammonia water, and the common (wt) concentration freezing point is about-35 ℃, and the ammonia water reacts with acid to generate heat, so that the risk of combustion explosion exists. Pumping quantitative ammonia water into a reaction kettle from an ammonia water storage tank through a centrifugal pump, adding the reaction materials in the second step into the reaction kettle quantitatively, mixing the reaction materials in the reaction kettle to react, heating the reaction kettle, stirring the materials in the reaction kettle, heating the materials in the reaction kettle by steam after the reaction of the materials in the reaction kettle is finished, heating the materials to a temperature of more than 95 ℃ for 120 ℃, and standing and cooling the materials after the heating is finished;
Step four, washing and filter pressing
Discharging the supernatant fluid obtained after the materials in the reaction kettle in the third step are kept still to a wastewater receiving tank, adding pure water into the slurry of the precipitation reactant to wash for 1-3 times, wherein the pure water is 4950t/a, placing the slurry into the slurry receiving tank, pumping the slurry from the slurry receiving tank into a filter press for filter pressing by a feed pump, allowing the wastewater subjected to filter pressing by a plate-and-frame filter press to enter the wastewater receiving tank, and pumping the wastewater into a wastewater tank by a centrifugal pump;
step five, roasting and oxidizing
Conveying the filter cake produced in the fourth step to an electric kiln workshop through a forklift, roasting at a high temperature of 600-800 ℃ through an electric kiln, treating waste gas produced by roasting through a spraying system, discharging the waste gas through an exhaust pipe, and roasting the filter cake at a high temperature to enable the filter cake to undergo an oxidation reaction to obtain high-purity cerium oxide;
Step six, grinding
Then, carrying out wet grinding on the high-purity cerium oxide generated in the step five, wherein the pure water amount used in the process is 252t/a;
The physical mechanical grinding method can lead the powder material to reach the nanometer, namely dry grinding and wet grinding, and for the manufacture of nanometer powder, it is of course desirable to obtain the final nanometer powder by a dry grinding method. However, when the powder is mechanically ground, the temperature of the powder is rapidly increased by the introduction of a large amount of energy during the grinding process, and it is difficult to control the grinding machine as to how to avoid the explosion-proof problem after the particles are refined. Therefore, in general, the particle size of dry milling can only be milled to 8. Mu.m. If a particle size of 8 μm or less is to be obtained, wet milling must be used. Grinding the resulting powder with a wet grinder is the most efficient and economical method. The method avoids the high cost of chemical nano powder manufacture and the defect that the mechanical dry grinding fineness is difficult to reach nano powder.
Wet grinding is to mix the nano powder with a proper solvent to prepare a proper material. In order to avoid the phenomenon of powder agglomeration in the grinding process, proper dispersing agents or auxiliary agents are needed to be added as grinding aids.
If the final nanoscale product is desired to be a powder rather than a slurry, consideration must be given to how to filter the large particles in the slurry first and how to dry the filtered slurry to obtain the nanoscale powder. The bead mill for wet grinding is to determine how large zirconia beads are selected according to the initial particle size and the final fineness of the materials.
The dry grinding particle size can only be ground to about 8um, if the grinding operation is to be performed in a finer or nanoscale manner, the wet grinding is performed by using wet grinding, wherein the water content of the material is not more than 4%, and the wet grinding is performed by suspending the raw material in carrier liquid flow for grinding, and adding additives such as dispersing agents and the like to assist the grinding. When the water content of the material in the wet grinding machine exceeds 50%, the problem of dust flying can be overcome. In food processing, the ground material is often used as a preliminary operation for leaching, making the components easy to dissolve out, and is therefore well suited for wet grinding processes. Wet operations generally consume more energy than dry operations and the wear of equipment is also more severe.
Seventh, filling
And after wet grinding, filling the slurry into a high-purity nano polishing solution finished product, wherein the filling of the polishing solution is common knowledge of a person skilled in the art and is not described in detail again.
Step four, wastewater generated by the spraying system is discharged into a four-effect evaporation processor for treatment, the treated water is recycled, specifically, after slurry generated by precipitation reaction is kept stand, generated waste supernatant is discharged into a wastewater receiving tank and finally enters a wastewater land tank, the wastewater is discharged into the wastewater receiving tank after the wastewater is treated by a four-effect evaporator, the non-discharged precipitation reactant slurry is washed by pure water, and finally enters the wastewater land tank, and the wastewater is treated by the four-effect evaporator and is not discharged; the washed slurry is subjected to plate and frame filter pressing to generate filter pressing wastewater which is discharged to a wastewater receiving tank and finally enters a wastewater land tank, and the wastewater is not discharged when being treated by a four-effect evaporator; the wastewater of the water spray tower is recycled after being subjected to sedimentation treatment in a sedimentation tank, and is not discharged; the waste water of the alkali spray tower is recycled after being treated by a plate-and-frame filter press, and is not discharged.
The above description is only of the preferred embodiments of the present invention and is not intended to limit the present invention, and various modifications and variations may be made to the present invention by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims (7)

1. A production process of nano rare earth polishing solution is characterized in that: the method comprises the following steps:
Step one, preparing cerium nitrate solution
Pumping quantitative pure water into a solution tank from a pure water storage tank through a pump, adding cerium nitrate crystals into the solution tank through a vacuum suction machine, stirring in the solution tank until the cerium nitrate crystals are completely dissolved to obtain high-purity cerium nitrate feed liquid, and pumping the high-purity cerium nitrate feed liquid into a storage tank through a centrifugal pump;
step two, oxidation reaction
Pumping the cerium nitrate solution prepared in the first step into a high-level metering tank through a centrifugal pump from a storage tank, quantitatively adding the cerium nitrate solution into the solution tank through the high-level metering tank, quantitatively adding hydrogen peroxide into the solution tank, mixing the hydrogen peroxide and the cerium nitrate solution in the storage tank to perform oxidation reaction, and pumping the cerium nitrate solution into the high-level metering tank through the centrifugal pump after the oxidation reaction is completed;
Step three, synthesis reaction
Pumping quantitative ammonia water into a reaction kettle from an ammonia water storage tank through a centrifugal pump, adding the reaction materials in the second step into the reaction kettle quantitatively, mixing the reaction materials in the reaction kettle to react, heating the materials in the reaction kettle by steam after the reaction of the materials is finished, and standing and cooling the materials after the heating is finished;
Step four, washing and filter pressing
Discharging the supernatant fluid of the materials in the reaction kettle in the third step to a wastewater receiving tank, adding pure water into the slurry for washing for 1-3 times, placing the slurry into the slurry receiving tank, pumping the slurry from the slurry receiving tank into a filter press for press filtration by a feed pump, enabling the wastewater pressed by the filter press to enter the wastewater receiving tank, and pumping the wastewater to a wastewater tank by a centrifugal pump;
step five, roasting and oxidizing
Conveying the filter cake generated in the step four to an electric kiln workshop through a forklift, roasting at a high temperature through an electric kiln, treating waste gas generated by roasting through a spraying system, discharging the waste gas through an exhaust pipe, roasting the filter cake at the high temperature to enable the filter cake to undergo an oxidation reaction, and oxidizing to obtain high-purity cerium oxide;
Step six, grinding
Then, carrying out wet grinding on the high-purity cerium oxide generated in the step five;
Seventh, filling
And (5) after wet grinding, filling the finished product into a high-purity nano polishing solution product.
2. The process for producing the nano rare earth polishing solution according to claim 1, which is characterized in that: and in the third step, the materials in the reaction kettle are heated by steam to 95-120 ℃.
3. The process for producing the nano rare earth polishing solution according to claim 1, which is characterized in that: and in the fourth step, the filter cake is roasted at a high temperature by an electric kiln, wherein the roasting temperature is 600-800 ℃.
4. The process for producing the nano rare earth polishing solution according to claim 1, which is characterized in that: the centrifugal pump is a fluoroplastic centrifugal pump.
5. The process for producing the nano rare earth polishing solution according to claim 1, which is characterized in that: and the waste gas generated in the third step and the fifth step is input into a spraying system for treatment and then is discharged.
6. The process for producing the nano rare earth polishing solution according to claim 5, wherein the process comprises the following steps: and step four, the wastewater generated by the spraying system is discharged into a four-effect evaporation processor for treatment, and the treated water is recycled.
7. The process for producing the nano rare earth polishing solution according to claim 1, which is characterized in that: and in the third step, the materials in the reaction kettle are stirred while the reaction kettle is heated.
CN202410116854.XA 2024-01-29 2024-01-29 Production process of nano rare earth polishing solution Pending CN117945450A (en)

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Application Number Priority Date Filing Date Title
CN202410116854.XA CN117945450A (en) 2024-01-29 2024-01-29 Production process of nano rare earth polishing solution

Publications (1)

Publication Number Publication Date
CN117945450A true CN117945450A (en) 2024-04-30

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Application Number Title Priority Date Filing Date
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