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CN117720337A - Method for producing alumina by using aluminum ash and utilizing tail gas - Google Patents

Method for producing alumina by using aluminum ash and utilizing tail gas Download PDF

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Publication number
CN117720337A
CN117720337A CN202311764230.0A CN202311764230A CN117720337A CN 117720337 A CN117720337 A CN 117720337A CN 202311764230 A CN202311764230 A CN 202311764230A CN 117720337 A CN117720337 A CN 117720337A
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China
Prior art keywords
aluminum ash
utilizing
gas
hydrogen
tunnel kiln
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CN202311764230.0A
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Chinese (zh)
Inventor
宋子堃
杨廉君
刘春连
宋韶文
宋子泓
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Guangdong Jinyi New Materials Technology Co ltd
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Guangdong Jinyi New Materials Technology Co ltd
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Priority to CN202311764230.0A priority Critical patent/CN117720337A/en
Publication of CN117720337A publication Critical patent/CN117720337A/en
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Abstract

The invention discloses a method for producing alumina by utilizing aluminum ash and utilizing tail gas, which relates to the technical field of metal processing and comprises the following steps: s1, placing process aluminum ash into a reaction container for cracking and deamination, and generating mixed gas of hydrogen, ammonia and water vapor during the cracking and deamination reaction; s2, placing the process aluminum ash into ball milling equipment and iron removing equipment, wherein the iron removing equipment removes iron, nickel, chromium and oxides on the process aluminum ash; s3, placing the process aluminum ash into a brick press for brick pressing treatment; s4, placing the mixture into a tunnel kiln to be roasted at 1400 ℃ to remove anions, and introducing the mixed gas in S1 into the tunnel kiln to be heated in an auxiliary way after water is removed; s5, placing the mixture into ball mill equipment to grind into ultrafine powder after cooling, and obtaining an alumina product with higher purity and whiteness; the invention has the advantages of avoiding the direct emission of hydrogen and methane, reducing the consumption of natural gas, reducing the nitrogen oxides in the combustion tail gas and preparing the alumina product.

Description

Method for producing alumina by using aluminum ash and utilizing tail gas
Technical Field
The invention relates to the technical field of metal processing, in particular to a method for producing aluminum oxide by utilizing aluminum ash and utilizing tail gas.
Background
The aluminum element belongs to an element with rich content in metal elements, and is widely applied to large industrial fields such as heavy industry, aviation industry, building industry and the like due to unique properties of aluminum materials. The production amount of 2023 aluminum products is estimated to be up to 10000 ten thousand tons, 30-110 kg aluminum ash can be produced when 1 ton of aluminum is refined, and the annual output of domestic aluminum ash can be up to 1000 ten thousand tons through preliminary measurement. The aluminum ash is used as main waste generated in the aluminum smelting process and is listed as T-grade dangerous waste in the national dangerous waste directory.
The aluminum ash can be classified into primary aluminum ash and secondary aluminum ash. The primary aluminum ash is mainly aluminum ash slag generated in the aluminum production process, is gray white, and mainly comprises metal aluminum and oxides thereof, wherein the aluminum content accounts for more than 50% of the total mass. The secondary aluminum ash is residues after primary aluminum ash or other waste aluminum are subjected to metal aluminum extraction by a physical method or a chemical method, and is gray black, and the aluminum content accounts for 5-30% of the total mass. The main starting point of the aluminum ash treatment process is to recover metal aluminum from primary aluminum ash and extract and utilize various element resources in secondary aluminum ash.
The current disposal methods of secondary aluminum ash are classified into a fire method and a wet method. The wet treatment adopts different leaching media to treat the secondary aluminum ash, so that the aluminum nitride is efficiently hydrolyzed, soluble fluoride and chloride are leached, the efficient removal of toxic components such as nitrogen, fluorine and chlorine is realized, and the harmless treatment is realized.
In the wet treatment process, aluminum nitride, metallic aluminum and aluminum carbide contained in the aluminum ash are hydrolyzed to generate gases such as ammonia gas, hydrogen gas and methane (natural gas), the existing technical route is to absorb the ammonia gas by using water, dilute sulfuric acid and the like to produce ammonia water or ammonium sulfate, and the hydrogen gas and the methane are discharged along with tail gas, so that the hydrogen gas and the methane cannot be effectively utilized, and the resource waste is caused.
Disclosure of Invention
The invention provides a technical scheme capable of solving the problems in order to overcome the defects of the prior art.
A method for producing alumina by using aluminum ash and utilizing tail gas comprises the following steps:
s1, placing process aluminum ash into a reaction container for cracking and deamination, and generating mixed gas of hydrogen, ammonia and water vapor during the cracking and deamination reaction;
s2, placing the process aluminum ash into ball milling equipment and iron removing equipment, wherein the ball milling equipment reduces the particle size of the process aluminum ash, and the iron removing equipment removes metals and oxides such as iron, nickel, chromium and the like on the process aluminum ash;
s3, placing the process aluminum ash into a brick press for brick pressing treatment to obtain bricks;
step S4, placing the bricks into a tunnel kiln, roasting at 1400 ℃ to remove anions such as chlorine, fluorine and the like, and introducing the mixed gas in the step S1 into the tunnel kiln for auxiliary heating after water removal;
and S5, waiting for cooling the brick, and putting the cooled brick into ball mill equipment to grind into ultrafine powder to obtain an alumina product with higher purity and whiteness.
As a further scheme of the invention: in the step S1, the mixed gas is conveyed to a condenser through negative pressure to remove water, and then is conveyed to a tunnel kiln in the step S4 to be burnt to assist the tunnel kiln to heat.
As a further scheme of the invention: the mixed gas before water removal has water vapor content of 90-97%, hydrogen content of 3-6% and ammonia content of 0.5-2%, wherein more than 95% of water vapor is condensed into water by a condenser.
As a further scheme of the invention: the content of ammonia gas after water removal is 10-30%, the content of hydrogen gas is 60-80%, and the content of water vapor is 1-5%.
As a further scheme of the invention: and a hydrogen-ammonia burner is arranged in the tunnel kiln, and the mixed gas enters the hydrogen-ammonia burner to perform stable combustion, so that heat is provided for roasting of the tunnel kiln.
As a further scheme of the invention: the temperature of the mixed gas generated by the cracking deamination reaction is 100-150 ℃, and the temperature of the water vapor is reduced to 50-70 ℃ when the water vapor is condensed into water.
As a further scheme of the invention: natural gas and mixed gas are input into the tunnel kiln for combustion, and the use ratio of the mixed gas to the natural gas is 1.5-2.5:2.5-3.5.
As a further scheme of the invention: the denitration catalytic device is arranged in the tunnel kiln, the denitration catalytic device uses a selective catalytic reduction technology, and the tunnel kiln fully utilizes ammonia, hydrogen and natural gas to burn and heat through the hydrogen ammonia burner and the denitration catalytic device, so that the denitration effect during combustion is ensured.
As a further scheme of the invention: the ratio of the mixed gas to the natural gas is 2:3.
As a further scheme of the invention: the chemical formula of ammonia combustion is 4NH 3 +3O 2 =2N 2 +6H 2 O、4xNH 3 +6NO x =(2x+3)N 2 +6xH 2 O; the chemical formula of hydrogen combustion is 2H 2 +O 2 =2H 2 O; the chemical formula of the natural gas combustion is CH 4 +2O 2 =CO 2 +2H 2 O。
Compared with the prior art, the invention has the beneficial effects that:
1. the ammonia gas, hydrogen gas and methane mixed gas generated by deamination are fully utilized, and the emission of hydrogen gas and methane is avoided;
2. the consumption of natural gas can be reduced by more than 35%, and the energy consumption is reduced;
3. the emission of nitrogen oxides in the tail gas of combustion can be effectively reduced, and the emission concentration of nitrogen oxide compounds in the tail gas is reduced by 47%;
4. can prepare alumina products with higher purity and whiteness.
Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.
Drawings
In order to more clearly illustrate the embodiments of the invention or the technical solutions of the prior art, the drawings which are used in the description of the embodiments or the prior art will be briefly described, it being obvious that the drawings in the description below are only some embodiments of the invention, and that other drawings can be obtained according to these drawings without inventive faculty for a person skilled in the art.
FIG. 1 is a schematic flow diagram of the present invention;
FIG. 2 is a schematic view of the structure of the tunnel kiln of the present invention;
FIG. 3 is a schematic view of the internal structure of the tunnel kiln of the present invention;
FIG. 4 is a schematic view of the structure of the burner of the present invention;
FIG. 5 is a schematic representation of the composition ratio before and after water removal according to the present invention.
Detailed Description
The following description of the embodiments of the present invention will be made apparent and fully in view of the accompanying drawings, in which some, but not all embodiments of the invention are shown.
The components of the embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations. Thus, the following detailed description of the embodiments of the invention, as presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention.
All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
In the description of the present invention, it should be noted that the directions or positional relationships indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. are based on the directions or positional relationships shown in the drawings, are merely for convenience of describing the present invention and simplifying the description, and do not indicate or imply that the devices 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. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.
In the description of the present invention, it should be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be either fixedly connected, detachably connected, or integrally connected, for example; 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.
As shown in fig. 1 to 5, the method for producing alumina by using aluminum ash and utilizing tail gas according to the invention comprises the following steps:
s1, placing process aluminum ash into a reaction container for cracking and deamination, and generating mixed gas of hydrogen, ammonia and water vapor during the cracking and deamination reaction;
s2, placing the process aluminum ash into ball milling equipment and iron removing equipment, wherein the ball milling equipment reduces the particle size of the process aluminum ash, and the iron removing equipment removes iron, nickel, chromium and oxides on the process aluminum ash;
s3, placing the process aluminum ash into a brick press for brick pressing treatment to obtain bricks;
s4, placing the bricks into a tunnel kiln, roasting at 1400 ℃ to remove anions, and introducing the mixed gas in the step S1 into the tunnel kiln for auxiliary heating after water removal;
and S5, waiting for cooling the brick, and putting the cooled brick into ball mill equipment to grind into ultrafine powder to obtain an alumina product with higher purity and whiteness.
As a further scheme of the invention: in the step S1, the mixed gas is conveyed to a condenser through negative pressure to remove water, and then is conveyed to a tunnel kiln in the step S4 to be burnt to assist the tunnel kiln to heat.
As a further scheme of the invention: the mixed gas before water removal has water vapor content of 90-97%, hydrogen content of 3-6% and ammonia content of 0.5-2%, wherein more than 95% of water vapor is condensed into water by a condenser.
As a further scheme of the invention: the content of ammonia gas after water removal is 10-30%, the content of hydrogen gas is 60-80%, and the content of water vapor is 1-5%.
As a further scheme of the invention: and a hydrogen-ammonia burner is arranged in the tunnel kiln, and the mixed gas enters the hydrogen-ammonia burner to perform stable combustion, so that heat is provided for roasting of the tunnel kiln.
As a further scheme of the invention: the temperature of the mixed gas generated by the cracking deamination reaction is 100-150 ℃, and the temperature of the water vapor is reduced to 50-70 ℃ when the water vapor is condensed into water.
As a further scheme of the invention: the natural gas and the mixed gas are input into the tunnel kiln for combustion, and the heat value of the natural gas is 37MJ/m, the heat value of the ammonia gas is 16MJ/m and the heat value of the hydrogen gas is 12MJ/m, the use ratio of the mixed gas to the natural gas is 1.5-2.5:2.5-3.5, the use amount of the natural gas can be effectively reduced by taking the ammonia gas and the hydrogen gas as heat sources, and the use amount of the natural gas in the process can be reduced by more than 35% through calculation.
As a further scheme of the invention: the denitration catalytic device is arranged in the tunnel kiln, the denitration catalytic device uses a selective catalytic reduction technology, the tunnel kiln fully utilizes ammonia, hydrogen and natural gas to burn and heat through the hydrogen ammonia burner and the denitration catalytic device, so that the denitration effect during combustion is ensured, the generation of nitrogen oxides in the combustion tail gas can be greatly reduced, and through calculation, the emission concentration of nitrogen oxides in the tail gas can be reduced by 47%, and the effects of carbon reduction and emission reduction can be achieved.
As a further scheme of the invention: the ratio of the mixed gas to the natural gas is 2:3.
As a further scheme of the invention: the chemical formula of ammonia combustion is 4NH 3 +3O 2 =2N 2 +6H 2 O、4xNH 3 +6NO x =(2x+3)N 2 +6xH 2 O; the chemical formula of hydrogen combustion is 2H 2 +O 2 =2H 2 O; the chemical formula of the natural gas combustion is CH 4 +2O 2 =CO 2 +2H 2 O。
The invention is used for the comprehensive treatment and the productization production of the secondary aluminum ash, can fully utilize the ammonia gas and the hydrogen gas generated during deamination, and is mutually mixed with the natural gas, thereby avoiding the emission of the hydrogen gas and the natural gas; the natural gas loss in production can be effectively reduced, and the use amount of the natural gas can be reduced by more than 35%; can effectively reduce the emission of nitrogen oxides in the combustion tail gas, and the emission concentration of nitrogen oxide compounds in the tail gas is reduced by 47%.
The present embodiment is not limited in any way by the shape, material, structure, etc. of the present invention, and any simple modification, equivalent variation and modification made to the above embodiments according to the technical substance of the present invention are all included in the scope of protection of the technical solution of the present invention.

Claims (10)

1. The method for producing alumina by using aluminum ash and utilizing tail gas is characterized by comprising the following steps:
s1, placing process aluminum ash into a reaction container for cracking and deamination, and generating mixed gas of hydrogen, ammonia and water vapor during the cracking and deamination reaction;
s2, placing the process aluminum ash into ball milling equipment and iron removing equipment, wherein the ball milling equipment reduces the particle size of the process aluminum ash, and the iron removing equipment removes iron, nickel, chromium and oxides on the process aluminum ash;
s3, placing the process aluminum ash into a brick press for brick pressing treatment to obtain bricks;
s4, placing the bricks into a tunnel kiln, roasting at 1400 ℃ to remove anions, and introducing the mixed gas in the step S1 into the tunnel kiln for auxiliary heating after water removal;
and S5, waiting for cooling the brick, and putting the cooled brick into ball mill equipment to grind into ultrafine powder to obtain an alumina product with higher purity and whiteness.
2. The method for producing alumina and utilizing tail gas by utilizing aluminum ash according to claim 1, wherein the method comprises the following steps: in the step S1, the mixed gas is conveyed to a condenser through negative pressure to remove water, and then is conveyed to a tunnel kiln in the step S4 to be burnt to assist the tunnel kiln to heat.
3. The method for producing alumina and utilizing tail gas by utilizing aluminum ash according to claim 2, wherein the method comprises the following steps: the mixed gas before water removal has water vapor content of 90-97%, hydrogen content of 3-6% and ammonia content of 0.5-2%, wherein more than 95% of water vapor is condensed into water by a condenser.
4. A method for producing alumina from aluminum ash and utilizing tail gas according to any one of claims 2 or 3, wherein: the content of ammonia gas after water removal is 10-30%, the content of hydrogen gas is 60-80%, and the content of water vapor is 1-5%.
5. The method for producing alumina and utilizing tail gas by utilizing aluminum ash according to claim 4, wherein the method comprises the following steps: and a hydrogen-ammonia burner is arranged in the tunnel kiln, and the mixed gas enters the hydrogen-ammonia burner to perform stable combustion, so that heat is provided for roasting of the tunnel kiln.
6. A method for producing alumina and utilizing tail gas by utilizing aluminum ash according to any one of claims 2 or 5, wherein the method comprises the following steps: the temperature of the mixed gas generated by the cracking deamination reaction is 100-150 ℃, and the temperature of the water vapor is reduced to 50-70 ℃ when the water vapor is condensed into water.
7. The method for producing alumina and utilizing tail gas by utilizing aluminum ash according to claim 6, wherein the method comprises the following steps: natural gas and mixed gas are input into the tunnel kiln for combustion, and the use ratio of the mixed gas to the natural gas is 1.5-2.5:2.5-3.5.
8. The method for producing alumina and utilizing tail gas by utilizing aluminum ash according to claim 7, wherein the method comprises the following steps: the denitration catalytic device is arranged in the tunnel kiln, the denitration catalytic device uses a selective catalytic reduction technology, and the tunnel kiln fully utilizes ammonia, hydrogen and natural gas to burn and heat through the hydrogen ammonia burner and the denitration catalytic device, so that the denitration effect during combustion is ensured.
9. The method for producing alumina and utilizing tail gas by utilizing aluminum ash according to claim 8, wherein the method comprises the following steps: the ratio of the mixed gas to the natural gas is 2:3.
10. The method for producing alumina and utilizing tail gas by utilizing aluminum ash according to claim 9, wherein the method comprises the following steps: the chemical formula of ammonia combustion is 4NH 3 +3O 2 =2N 2 +6H 2 O、4xNH 3 +6NO x =(2x+3)N 2 +6xH 2 O; the chemical formula of hydrogen combustion is 2H 2 +O 2 =2H 2 O; the chemical formula of the natural gas combustion is CH 4 +2O 2 =CO 2 +2H 2 O。
CN202311764230.0A 2023-12-21 2023-12-21 Method for producing alumina by using aluminum ash and utilizing tail gas Pending CN117720337A (en)

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Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH09202616A (en) * 1996-01-24 1997-08-05 Ishii Sangyo Kk Ceramic stock and its production
BG108601A (en) * 2004-02-25 2005-08-31 Елена КРУМОВА Process for the preparation of aluminium hydroxide and other aluminium compounds of waste aluminium-containing slags
JP2006283083A (en) * 2005-03-31 2006-10-19 Kobe Steel Ltd Aluminum ash, desulfurizing agent for steelmaking, and method for producing aluminum ash
CN114058855A (en) * 2021-11-16 2022-02-18 秦皇岛信宝资源循环科技有限公司 A kind of secondary aluminum ash harmless treatment process
CN115921501A (en) * 2022-12-29 2023-04-07 重庆煅鼎环境科技有限公司 A secondary aluminum ash treatment method for wet and dry combined denitrification, desalination and fluorine fixation
CN116329260A (en) * 2023-05-26 2023-06-27 佛山仙湖实验室 A combined treatment method of aluminum ash wet ammonia extraction, ammonia combustion, and denitrification
CN116408329A (en) * 2021-12-31 2023-07-11 上海善是科技有限公司 Aluminum ash innocent treatment and recycling process

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH09202616A (en) * 1996-01-24 1997-08-05 Ishii Sangyo Kk Ceramic stock and its production
BG108601A (en) * 2004-02-25 2005-08-31 Елена КРУМОВА Process for the preparation of aluminium hydroxide and other aluminium compounds of waste aluminium-containing slags
JP2006283083A (en) * 2005-03-31 2006-10-19 Kobe Steel Ltd Aluminum ash, desulfurizing agent for steelmaking, and method for producing aluminum ash
CN114058855A (en) * 2021-11-16 2022-02-18 秦皇岛信宝资源循环科技有限公司 A kind of secondary aluminum ash harmless treatment process
CN116408329A (en) * 2021-12-31 2023-07-11 上海善是科技有限公司 Aluminum ash innocent treatment and recycling process
CN115921501A (en) * 2022-12-29 2023-04-07 重庆煅鼎环境科技有限公司 A secondary aluminum ash treatment method for wet and dry combined denitrification, desalination and fluorine fixation
CN116329260A (en) * 2023-05-26 2023-06-27 佛山仙湖实验室 A combined treatment method of aluminum ash wet ammonia extraction, ammonia combustion, and denitrification

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