CN117286337A - Method for recovering chromium from chromite sand - Google Patents
Method for recovering chromium from chromite sand Download PDFInfo
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- CN117286337A CN117286337A CN202311202746.6A CN202311202746A CN117286337A CN 117286337 A CN117286337 A CN 117286337A CN 202311202746 A CN202311202746 A CN 202311202746A CN 117286337 A CN117286337 A CN 117286337A
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- chromium
- chromite
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
- C22B3/00—Extraction of metal compounds from ores or concentrates by wet processes
- C22B3/04—Extraction of metal compounds from ores or concentrates by wet processes by leaching
- C22B3/06—Extraction of metal compounds from ores or concentrates by wet processes by leaching in inorganic acid solutions, e.g. with acids generated in situ; in inorganic salt solutions other than ammonium salt solutions
- C22B3/08—Sulfuric acid, other sulfurated acids or salts thereof
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
- C22B1/00—Preliminary treatment of ores or scrap
- C22B1/02—Roasting processes
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
- C22B34/00—Obtaining refractory metals
- C22B34/30—Obtaining chromium, molybdenum or tungsten
- C22B34/32—Obtaining chromium
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P10/00—Technologies related to metal processing
- Y02P10/20—Recycling
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- Metallurgy (AREA)
- Mechanical Engineering (AREA)
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- Environmental & Geological Engineering (AREA)
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- Geochemistry & Mineralogy (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Inorganic Chemistry (AREA)
- Manufacture And Refinement Of Metals (AREA)
Abstract
The invention relates to the technical field of alloys, and provides a method for recycling chromium from chromite sand, which comprises the following steps: s1, crushing chromite, and performing ball milling activation to obtain activated chromite; s2, carrying out reduction roasting on activated chromite and ferrosilicon to obtain clinker; s3, cooling clinker, adding concentrated sulfuric acid for leaching to obtain leaching slag and chromium sulfate leaching liquid respectively; s4, separating leaching residues from the chromium sulfate leaching solution, evaporating the separated chromium sulfate leaching solution, and cooling and crystallizing to obtain chromium salt. By the technical scheme, the problems of complex roasting process conditions for recovering chromium, high energy consumption, low chromium leaching rate and serious pollution of chromium slag in the chromium salt preparation process in the prior art are solved.
Description
Technical Field
The invention relates to the technical field of alloys, in particular to a method for recycling chromium from chromite sand.
Background
Chromium is an important metal, and is widely used in the fields of metallurgy, chemical industry, cast iron, fire resistance, high-precision end science and technology and the like because of its excellent properties such as hardness, brittleness, corrosion resistance and the like. The metal chromium can be used as an additive of aluminum alloy, cobalt alloy, titanium alloy, high-temperature alloy, resistance heating alloy and the like, and when stainless steel is refined, chromium oxide layer is formed by doping chromium, so that corrosion of metal in the stainless steel can be effectively reduced. Meanwhile, chromium metal has been listed as one of the most important electroplated metals, and in most cases, chromium coatings are specially used as the outermost plating layers of parts, and the chromium coatings do not provide physical properties, and the service lives of most parts are greatly shortened due to abrasion, corrosion and the like. In the prior art, there is a process for extracting chromium from chromium slag, which mainly comprises the steps of solidifying and piling hexavalent chromium in the chromium slag after reduction or producing building materials, but the reduced chromium cannot be separated from residues, and the reduced trivalent chromium can be oxidized slowly, so that the potential pollution problem in the chromium slag cannot be solved. Chromium iron ore is the main raw material for producing chromium and chromium salt, the utilization rate of chromium resources is lower in the production process of the chromium salt, and the generated hexavalent chromium is extremely harmful to human bodies and the environment, and the chromium is mainly extracted from the chromium iron ore at present by a calcium roasting method, a calcium-free roasting method and a sub-molten salt method, but calcium-containing fillers such as limestone and the like are required to be added in the calcium roasting method, so that the process has large slag discharge amount, contains a large amount of indissolvable calcium chromate and is difficult to detoxify. The slag returning amount required to be added in the calcium-free roasting is large, so that less chromium is used as a roasting raw material, and the two roasting processes have high roasting temperature and high energy consumption, and the generated chromium slag contains hexavalent chromium, so that environmental pollution is caused, and continuous industrial production is difficult to realize. The sub-molten salt method has large alkali consumption, large alkali corrosion at high temperature and serious damage to equipment. The chromium salt preparation process has the problems of low chromium leaching rate and serious pollution of chromium slag. Therefore, the chromium resource in the chromite is fully utilized, the pollution problem in the production process is solved, and the reduction of the energy consumption of industrial production is extremely important.
Disclosure of Invention
The invention provides a method for recycling chromium from chromite sand, which solves the problems of complex roasting process conditions for recycling chromium, high energy consumption, low chromium leaching rate and serious pollution of chromium slag in a chromium salt preparation process.
The technical scheme of the invention is as follows:
the invention provides a method for recovering chromium from chromite sand, which comprises the following steps:
s1, crushing chromite, and performing ball milling activation to obtain activated chromite;
s2, carrying out reduction roasting on activated chromite and ferrosilicon to obtain clinker;
s3, cooling clinker, adding concentrated sulfuric acid for leaching to obtain leaching slag and chromium sulfate leaching liquid respectively;
s4, separating leaching residues from the chromium sulfate leaching solution, evaporating the separated chromium sulfate leaching solution, and cooling and crystallizing to obtain chromium salt.
As a further technical scheme, the chromite is subjected to modification treatment by a modifying agent before being crushed, wherein the modifying agent comprises the following components in parts by weight:
40-60 parts of limestone, 20-30 parts of montmorillonite and 5-10 parts of olivine.
According to the further technical scheme, the method for modifying the chromite comprises the steps of respectively crushing the chromite, limestone and olivine, mixing the crushed chromite, limestone and olivine with montmorillonite to obtain a mixture, and reacting the mixture at 800-900 ℃ for 20-30 min to obtain the modified chromite.
As a further technical scheme, the particle size of the activated chromite is 50-70 mu m.
As a further technical scheme, the mass ratio of the activated chromite to the ferrosilicon is 5:5-7:3.
As a further technical scheme, the reduction roasting temperature is 1000-1200 ℃, and the reduction roasting time is 2-3 h.
As a further technical scheme, sodium dodecyl sulfate is also added into the concentrated sulfuric acid, and the mass ratio of the concentrated sulfuric acid to the sodium dodecyl sulfate is 7:3-9:1.
As a further technical scheme, the mass ratio of the concentrated sulfuric acid to the clinker is 7:3-9:1.
As a further technical scheme, the leaching temperature is 100-150 ℃, and the leaching time is 3-5 h.
As a further technical scheme, the cooling crystallization temperature is 30-45 ℃.
The working principle and the beneficial effects of the invention are as follows:
1. according to the invention, the chromite is subjected to ball milling activation, so that the lattice structure of the chromite is destroyed, the melting point and stability of the chromite are further reduced, the chromite is decomposed more completely, and the leaching rate of chromium in the acid leaching process is greatly facilitated. The ferrochrome is reduced and activated by the ferrosilicon, so that trivalent chromium is prevented from being oxidized into hexavalent chromium, the generation of toxic hexavalent chromium is avoided, meanwhile, iron in the ferrochrome is converted into ferrous iron, and meanwhile, the generation of insoluble sulfate by the trivalent iron, the trivalent chromium and sulfuric acid is avoided, and the leaching rate of chromium is further reduced.
2. In the invention, limestone, montmorillonite and olivine with low magnesium and low aluminum content are adopted to modify the chromite, so that divalent magnesium ions with smaller radius in the chromite spinel structure can be avoided, trivalent aluminum ions replace divalent iron ions and trivalent chromium ions with larger radius in the chromite, thereby reducing the stability of the spinel structure in the chromite, being beneficial to thorough roasting and decomposition of the chromite and further improving the leaching rate of chromium.
3. In the invention, the surface tension between chromium and concentrated sulfuric acid can be reduced by adding the surfactant sodium dodecyl sulfate into the concentrated sulfuric acid, thereby promoting the dissolution of the chromium and effectively improving the leaching rate of the chromium.
Detailed Description
The technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention, and it is apparent that the described embodiments are only some embodiments of the present invention, not all embodiments. All other embodiments, which can be made by one of ordinary skill in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
Example 1
S1, crushing chromite, and ball milling for 2 hours for activation to obtain activated chromite with the particle size of 50 mu m;
s2, placing 200g of activated chromite into a roasting furnace, adding 200g of ferrosilicon at 1000 ℃, and carrying out reduction roasting for 2 hours to obtain clinker;
s3, cooling 70g of clinker to 150 ℃, adding 30g (16 mL) of concentrated sulfuric acid, and leaching for 3 hours to obtain leaching slag and chromium sulfate leaching liquid;
s4, separating leaching residues from the chromium sulfate leaching solution, evaporating the separated chromium sulfate leaching solution, and cooling and crystallizing at 30 ℃ to obtain chromium salt.
Example 2
S1, crushing chromite, and ball milling for 2 hours for activation to obtain activated chromite with the particle size of 70 mu m;
s2, placing 200g of activated chromite into a roasting furnace, adding 85g of ferrosilicon at 1200 ℃, and carrying out reduction roasting for 3 hours to obtain clinker;
s3, cooling 70g of clinker to 150 ℃, adding 7.8g (4.2 mL) of concentrated sulfuric acid, and leaching for 5 hours to obtain leaching slag and chromium sulfate leaching liquid;
s4, separating leaching residues from the chromium sulfate leaching solution, evaporating the separated chromium sulfate leaching solution, and cooling and crystallizing at 45 ℃ to obtain chromium salt.
Example 3
The difference between this example and example 1 is only that the chromite is added with a modifier for modification treatment before crushing, and the modification method is as follows: 200g of chromite, 20g of limestone and 2.5g of olivine are respectively crushed and then mixed with 10g of montmorillonite to obtain a mixture, and the mixture is reacted for 30min at 800 ℃ to obtain the modified chromite.
Example 4
The difference between this example and example 1 is only that the chromite is added with a modifier for modification treatment before crushing, and the modification method is as follows: 200g of chromite, 30g of limestone and 5g of olivine are respectively crushed and then mixed with 15g of montmorillonite to obtain a mixture, and the mixture is reacted for 20min at 900 ℃ to obtain the modified chromite.
Example 5
This example differs from example 3 only in that 10g of montmorillonite was replaced with 10g of kaolin in the upgrading process.
Example 6
This example differs from example 3 only in that no olivine was added to the upgrading process.
Example 7
The difference between this embodiment and embodiment 4 is that S3 is: 70g of clinker is cooled to 150 ℃, 30g (16 mL) of concentrated sulfuric acid and 12.9g of sodium dodecyl sulfate are added for leaching for 3 hours, and leaching slag and chromium sulfate leaching liquid are obtained.
Example 8
The difference between this embodiment and embodiment 4 is that S3 is: 70g of clinker is cooled to 150 ℃, 30g (16 mL) of concentrated sulfuric acid and 3.3g of sodium dodecyl sulfate are added for leaching for 3 hours, and leaching slag and chromium sulfate leaching liquid are obtained.
Example 9
The difference between this embodiment and embodiment 4 is that S3 is: 70g of clinker is cooled to 150 ℃, 30g (16 mL) of concentrated sulfuric acid and 12.9g of polyoxyethylene fatty acid ester are added, and leaching is carried out for 3 hours, thus obtaining leaching slag and chromium sulfate leaching liquid.
Comparative example 1
This comparative example differs from example 1 only in that no ferrosilicon is added in S2.
Comparative example 2
This comparative example differs from example 1 only in that S2 is: 200g of activated chromite is placed in a roasting furnace, 200g of charcoal is added at 1000 ℃ for reduction roasting for 2 hours, and clinker is obtained.
Comparative example 3
This comparative example differs from example 1 only in that no ball milling activation was performed after the chromite was crushed in S1.
The chromium content in the leachate and leached slag obtained in examples 1 to 9 and comparative examples 1 to 3 was measured by inductively coupled plasma spectrometry, and the leaching rate of chromium was calculated.
From the above, according to the experimental data of examples 1 to 9 and comparative examples 1 to 3, it is known that the leaching rate of chromium can be remarkably improved by performing ball milling activation on chromite, performing modification treatment before crushing the chromite, and adding a modifier with low magnesium and low aluminum content. The invention adopts the reduction reaction of ferrosilicon and chromite to lead the chromium to be completely reduced, thereby improving the leaching rate of the chromium. According to the invention, the sodium dodecyl sulfate surfactant is added into the pickle liquor concentrated sulfuric acid, so that the leaching rate of chromium can be remarkably improved.
From the experimental data of examples 1 and 3-4, it can be seen that the present invention can further improve the leaching rate of chromium by adding a modifying agent to the chromite for modification treatment before pulverization.
From the experimental data of examples 3 and 5-6, it can be seen that the leaching rate of chromium can be further improved by modifying limestone with limestone, montmorillonite and olive Dan Gaizhi.
From the experimental data of example 4 and examples 7-9, it can be seen that the leaching rate of chromium can be further improved by adding sodium dodecyl sulfate.
From the experimental data of example 1 and comparative examples 1-2, it can be seen that the leaching rate of chromium can be significantly improved by subjecting activated chromite and a ferrosilicon reducing agent to reduction roasting.
From the experimental data of example 1 and comparative example 3, it can be seen that the leaching rate of chromium can be significantly improved by ball milling activation after the chromite is crushed.
The foregoing description of the preferred embodiments of the invention is not intended to be limiting, but rather is intended to cover all modifications, equivalents, alternatives, and improvements that fall within the spirit and scope of the invention.
Claims (10)
1. A process for recovering chromium from chromite sand, comprising the steps of:
s1, crushing chromite, and performing ball milling activation to obtain activated chromite;
s2, carrying out reduction roasting on activated chromite and ferrosilicon to obtain clinker;
s3, cooling clinker, adding concentrated sulfuric acid for leaching to obtain leaching slag and chromium sulfate leaching liquid respectively;
s4, separating leaching residues from the chromium sulfate leaching solution, evaporating the separated chromium sulfate leaching solution, and cooling and crystallizing to obtain chromium salt.
2. The method for recovering chromium from chromite sand according to claim 1, wherein the chromite is upgraded with a modifier prior to comminution, the modifier comprising the following components in parts by weight:
40-60 parts of limestone, 20-30 parts of montmorillonite and 5-10 parts of olivine.
3. The method for recycling chromium from chromite sand according to claim 2, wherein the modification treatment method is to crush chromite, limestone and olivine respectively, then mix the crushed chromite, limestone and olivine with montmorillonite to obtain a mixture, and react the mixture at 800-900 ℃ for 20-30 min to obtain modified chromite.
4. The method for recovering chromium from chromite sand according to claim 1, wherein the particle size of the activated chromite is 50-70 μm.
5. The method for recovering chromium from chromite sand according to claim 1, wherein the mass ratio of activated chromite to ferrosilicon is 5:5-7:3.
6. The method for recovering chromium from chromite sand according to claim 1, wherein the reduction roasting temperature is 1000-1200 ℃, and the reduction roasting time is 2-3 hours.
7. The method for recycling chromium from chromite sand according to claim 1, wherein sodium dodecyl sulfate is further added into the concentrated sulfuric acid, and the mass ratio of the concentrated sulfuric acid to the sodium dodecyl sulfate is 7:3-9:1.
8. The method for recovering chromium from chromite sand according to claim 1, wherein the mass ratio of concentrated sulfuric acid to clinker is 7:3-9:1.
9. The method for recovering chromium from chromite sand according to claim 1, wherein the leaching temperature is 100-150 ℃ and the leaching time is 3-5 h.
10. The method for recovering chromium from chromite sand according to claim 1, wherein the cooling crystallization temperature is 30-45 ℃.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311202746.6A CN117286337B (en) | 2023-09-18 | 2023-09-18 | Method for recovering chromium from chromite sand |
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| CN202311202746.6A CN117286337B (en) | 2023-09-18 | 2023-09-18 | Method for recovering chromium from chromite sand |
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| CN117286337A true CN117286337A (en) | 2023-12-26 |
| CN117286337B CN117286337B (en) | 2024-03-15 |
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Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB223622A (en) * | 1923-04-27 | 1924-10-27 | Wilhelm Borchers | Improvements in or relating to the production of alloys containing iron and chromium |
| GB603973A (en) * | 1945-11-19 | 1948-06-25 | Hudson Bay Mining & Smelting | Improvements relating to the treatment of chromium ores |
| US5127939A (en) * | 1990-11-14 | 1992-07-07 | Ceram Sna Inc. | Synthetic olivine in the production of iron ore sinter |
| JPH10330822A (en) * | 1997-06-05 | 1998-12-15 | Nippon Yakin Kogyo Co Ltd | Recovery of valuable metals from industrial waste |
| CN108977607A (en) * | 2018-08-06 | 2018-12-11 | 王德清 | A kind of joint smelting process of high carbon ferro-chrome and forsterite |
| CN109022830A (en) * | 2018-07-27 | 2018-12-18 | 昆明理工大学 | A kind of microwave-ultrasonic combines the method for preparing high chromium product with salt Ore Leaching chromite |
| CN116555592A (en) * | 2023-05-26 | 2023-08-08 | 北京镜澄科技有限公司 | A kind of leaching method of chromium and iron in ferrochrome alloy |
-
2023
- 2023-09-18 CN CN202311202746.6A patent/CN117286337B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB223622A (en) * | 1923-04-27 | 1924-10-27 | Wilhelm Borchers | Improvements in or relating to the production of alloys containing iron and chromium |
| GB603973A (en) * | 1945-11-19 | 1948-06-25 | Hudson Bay Mining & Smelting | Improvements relating to the treatment of chromium ores |
| US5127939A (en) * | 1990-11-14 | 1992-07-07 | Ceram Sna Inc. | Synthetic olivine in the production of iron ore sinter |
| JPH10330822A (en) * | 1997-06-05 | 1998-12-15 | Nippon Yakin Kogyo Co Ltd | Recovery of valuable metals from industrial waste |
| CN109022830A (en) * | 2018-07-27 | 2018-12-18 | 昆明理工大学 | A kind of microwave-ultrasonic combines the method for preparing high chromium product with salt Ore Leaching chromite |
| CN108977607A (en) * | 2018-08-06 | 2018-12-11 | 王德清 | A kind of joint smelting process of high carbon ferro-chrome and forsterite |
| CN116555592A (en) * | 2023-05-26 | 2023-08-08 | 北京镜澄科技有限公司 | A kind of leaching method of chromium and iron in ferrochrome alloy |
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| CN117286337B (en) | 2024-03-15 |
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