A method for opening a furnace using a combined furnace-cracking device and an oxygen lance

Abstract

The present invention discloses a method for opening a furnace by combining a cracking device and an oxygen lance, relates to the technical field of opening a furnace in a blast furnace repair, and solves the technical problems that the oxygen burning method of the mixed material layer between the tuyere and the iron mouth takes a long time, the connecting channel is small, it is easy to be blocked, and the furnace opening recovery is slow. The method comprises: drilling a first channel along the iron mouth, inserting a cracking device into the first channel, and remotely detonating until a through channel is formed between the tuyere and the iron mouth, and after each iron mouth of the blast furnace forms a through channel, re-drilling a second channel along the iron mouth, inserting an oxygen lance into the second channel, and supplying air to the blast furnace, and the oxygen lance starts to supply air until the blast furnace taps iron for the first time or the iron mouth burns out automatically. This method realizes the large-area penetration of the 4-6 meter thick coke iron slag material layer between the tuyere and the iron mouth of a large blast furnace, and the oxygen lance supplies oxygen after the blast furnace supplies air, which can realize the good penetration of slag iron in the furnace cylinder before the tuyere and the furnace cylinder temperature increase, creating good conditions for the first tapping of iron in the blast furnace.

Description

Technical Field

[0001] The invention relates to the technical field of blast furnace repair and opening, and in particular to a combined furnace opening method using a cracking device and an oxygen lance. Background Art

[0002] The height between the tuyere and the taphole of a blast furnace is about 4-5 meters, and the vertical height between the tuyere and the taphole of a large blast furnace reaches 5-6 meters. The mixture between the tuyere and the taphole is mainly coke and supplemented by slag and iron. When the repair time is as long as 5-30 days, the mixture layer between the tuyere and the taphole, especially the slag and iron mixture, will condense to form a barrier layer, which will prevent the slag and iron materials from penetrating into the furnace after the blast furnace is supplied with air, and slag and iron will accumulate in front of the tuyere, resulting in tuyere damage, slow air supply speed and other problems, which seriously affect the progress of blast furnace air supply recovery.

[0003] At present, the common practice is to introduce oxygen from the tuyere downward and the iron mouth upward before starting the furnace, and make the tuyere and the iron mouth connected through combustion. However, the vertical distance between the tuyere and the iron mouth is extremely large, especially in large blast furnaces. The thickness of the mixed material layer between the tuyere and the iron mouth is large, and the slag iron layer is difficult to melt. It takes 24 hours or even longer to burn the tuyere and the iron mouth; in addition, the size of the channel between the tuyere and the iron mouth burned through by oxygen is limited, which is easy to be blocked during the subsequent charging process, hindering the slag iron permeability of the mixed material layer between the tuyere and the iron mouth. Summary of the invention

[0004] The present application provides a combined furnace opening method using a cracking device and an oxygen lance, which solves the technical problems in the related art that the method of oxygen burning through the mixed material layer between the tuyere and the iron mouth takes a long time, the connecting channel is small, easy to be blocked, and the furnace opening recovery is slow.

[0005] The present application provides a combined furnace opening method using a cracker and an oxygen lance, comprising: using an opening machine to drill along the iron mouth to a depth of 0.8-1.5m inside the furnace wall of a blast furnace to form a first channel; after the first channel is formed, inserting the cracker into the first channel, with the front blast hole of the cracker facing upward; after the cracker is inserted into the first channel, rotating the mud gun head to the rear end of the exposed part of the cracker from the iron mouth, performing remote detonation, generating an explosive force of 100-300MPa upward at the blast hole, and pulling out the cracker after the blasting is completed; after the cracker is pulled out, placing a reference object for inspection at the first channel, and if the inspection result is positive, the reference object is placed at the first channel. If no through-channel is formed between the tuyere and the iron mouth, repeat the operation from forming the first channel to pulling out the cracking device until a through-channel is formed between the tuyere and the iron mouth. After a through-channel is formed at each iron mouth of the blast furnace, use an opening machine to drill again along the iron mouth to a position 1-1.5m inside the blast furnace wall to form a second channel connected to the through-channel. After the second channel is formed, insert the oxygen lance into the second channel, with the front end of the oxygen lance being 0.5-0.6m away from the inside of the blast furnace wall. After the oxygen lance is inserted into the second channel, the blast furnace is supplied with air, and the oxygen lance starts to supply air until the blast furnace taps iron for the first time or the iron mouth burns out automatically.

[0006] In some embodiments, after a through channel is formed with the blasting hole facing upward, the blasting hole is deviated 15°-20° to the left and 15°-20° to the right from the vertical direction to perform a blasting operation from forming the first channel to pulling out the fracturing device.

[0007] In some embodiments, using an opening machine to drill along the iron mouth to a depth of 0.8-1.5 m inside the blast furnace wall to form a first channel includes:

[0008] For 1000-2000m 3 For blast furnaces, the drilling depth of the opening machine is 0.8m inside the blast furnace wall;

[0009] For 2000-3000m 3 For blast furnaces, the drilling depth of the opening machine is 1.0m inside the blast furnace wall;

[0010] For 3000-4000m 3 For blast furnaces, the drilling depth of the opening machine is 1.2m inside the blast furnace wall;

[0011] For 4000m 3 For blast furnaces above 1000 mm, the drilling machine drills to a depth of 1.4-1.5 m inside the blast furnace wall.

[0012] In some embodiments, after forming the first channel and before inserting the fracture device into the first channel, the method further comprises:

[0013] Use a chisel to remove the slag in the first hole.

[0014] In some embodiments, the cracker is connected by 2-5 sections, each section is 0.8-1.5m long; when the cracker is inserted into the first channel, the front blasting hole of the cracker is located 0.8-1.5m inside the blast furnace wall.

[0015] In some embodiments, for 1000-2000 m 3 For blast furnaces, two-stage fracturing devices, each with a length of 1.4-1.5m, are used for fracturing blasting;

[0016] For 2000-3000m 3 For blast furnaces, three-stage fracturing devices, each with a length of 1.2-1.3m, are used for fracturing blasting;

[0017] For 3000-4000m 3 For blast furnaces, four-stage fracturing devices, each with a length of 1.0-1.2m, are used for fracturing blasting;

[0018] For 4000m 3 For the above blast furnaces, 5-section crackers with each section of 0.8-1.1m are used for cracking blasting.

[0019] In some embodiments, for 1000-2000 m 3 For a blast furnace, under the condition of remote detonation, an explosion force of not less than 150MPa is generated upwards from the blast hole;

[0020] For 2000-3000m 3 For a blast furnace, under the condition of remote detonation, an explosion force of not less than 180MPa is generated upwards from the blast hole;

[0021] For 3000-4000m 3 For a blast furnace, under the condition of remote detonation, an explosion force of not less than 200MPa is generated upwards from the blast hole;

[0022] For 4000m 3 The above blast furnaces, under the condition of remote detonation, generate an explosion force of not less than 250MPa upwards at the blast hole.

[0023] In some embodiments, the reference object includes a lighter flame or a ribbon, which is placed at the outer end of the first channel. If the lighter flame or the ribbon is tilted toward the furnace, a through channel is formed; if the lighter flame is vertically upward or the ribbon is stationary, a through channel has not yet been formed between the air port and the iron mouth. The operation from forming the first channel to pulling out the cracking device is repeated until the lighter flame or the ribbon is tilted toward the furnace.

[0024] In some embodiments, inserting the oxygen lance into the second hole includes: filling a gap between the oxygen lance and the second hole with taphole mud;

[0025] The oxygen lance is arranged in a casing structure, with oxygen passing through the inner tube of the oxygen lance and air passing through the outer tube.

[0026] In some embodiments, the oxygen lance starts to supply gas, including: the oxygen lance starts to introduce oxygen and air, and the pressure of oxygen and air is controlled at 0.6-1.0 MPa.

[0027] The beneficial effects of the present application are as follows: a method for opening a furnace using a combined method of a cracker and an oxygen lance is provided, a first channel is formed by drilling from the iron mouth to a depth of 0.8-1.5m from the inner side of the blast furnace wall by using a blast furnace front opening machine, a use environment for the cracker is provided, the cracker is used as a liquid carbon dioxide blasting device, remote detonation is performed through the cracker, and the explosion force is limited to 100-300MPa, thereby achieving large-area communication of the coke-iron-slag mixed layer between the tuyere and the iron mouth, and providing a large number of gas channels for subsequent oxygen lance oxygen injection; by selecting a reference object to check whether a penetration is formed between the tuyere and the iron mouth, if not, the above operation is continued; until the penetration is completed to form a through channel; a penetration is formed at each iron mouth After the passage is cleared, the blast furnace opening machine in front of the blast furnace is used again to drill deeper along the iron mouth to 1-1.5m inside the blast furnace wall to form a second channel to provide an environment for the use of the oxygen gun. The oxygen gun delivers oxygen after the blast furnace is supplied with air, which can achieve good penetration of the slag and iron in front of the tuyere in the furnace hearth and increase the temperature of the furnace hearth. The slag and iron formed in front of the tuyere penetrate and drip from the tuyere to the iron mouth position more smoothly, creating good conditions for the first iron tapping of the blast furnace, and effectively avoiding the shortcomings of artificial oxygen burning through the tuyere iron mouth for a long time, poor effect, and easy blockage. At the same time, it avoids the poor permeability of the slag and iron in the furnace hearth below the tuyere after the blast furnace is supplied with air, the tuyere is easy to damage, the air addition speed is slow, and other phenomena that affect the recovery of the blast furnace, and can achieve rapid full air recovery of the blast furnace. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for describing the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention.

[0029] Figure 1 A schematic diagram of a first state of a combined furnace opening method using a cracker and an oxygen lance provided in the present application;

[0030] Figure 2 A schematic diagram of a second state of a combined furnace opening method using a cracker and an oxygen lance provided in the present application;

[0031] Figure 3 A schematic diagram of the structure of an oxygen lance in a combined furnace opening method using a cracker and an oxygen lance provided in the present application;

[0032] Figure 4 A schematic flow chart of a combined furnace opening method utilizing a cracker and an oxygen lance is provided in the present application.

[0033] The attached drawings are marked with: 100 - first channel, 200 - cracker, 210 - blasting hole, 300 - second channel, 400 - oxygen lance, 410 - inner tube, 420 - outer tube, 20 - tuyere, 30 - iron mouth, 40 - blast furnace wall, 50 - coke-iron-slag mixed layer. DETAILED DESCRIPTION

[0034] The embodiment of the present application provides a combined furnace opening method using a cracking device and an oxygen lance, thereby solving the technical problems in the related art that the method of oxygen burning through the mixed material layer between the tuyere and the iron mouth takes a long time, the connecting passage is small, is easily blocked, and the furnace opening recovery is slow.

[0035] The technical solution in the embodiment of the present application is to solve the above technical problems, and the overall idea is as follows:

[0036] A combined furnace opening method using a cracker and an oxygen lance comprises: using an opening machine to drill along the iron mouth to a depth of 0.8-1.5m inside the furnace wall of a blast furnace to form a first channel; after the first channel is formed, inserting the cracker into the first channel, with the front end blasting hole of the cracker facing upward; after the cracker is inserted into the first channel, rotating the mud gun head to the rear end of the exposed part of the cracker from the iron mouth, performing remote detonation, generating an explosive force of 100-300MPa upward at the blasting hole, and pulling out the cracker after the blasting is completed; after the cracker is pulled out, placing a reference object for inspection at the first channel, and if the inspection tuyere and the blasting hole are aligned, the reference object for inspection is placed ... the reference object for inspection is placed at the first channel, and the reference object for inspection is placed at the first channel, and the reference object for inspection is placed at the first channel, and the reference object for inspection is placed at the first channel, and the reference object for inspection is placed at the first channel, and the reference object for inspection is placed at the first channel, and the reference object for inspection is placed at the first channel, and the reference object for inspection is placed at the first channel, and the reference object for inspection is placed at the first channel, and the reference object for inspection is placed at the first channel, and the reference object for inspection is placed at the first channel, and the reference object for inspection is placed at the first channel, If no through-channel is formed between the iron mouths, repeat the operation from forming the first channel to pulling out the cracking device until a through-channel is formed between the inspection tuyere and the iron mouth; after a through-channel is formed at each iron mouth of the blast furnace, use an opening machine to drill again along the iron mouth to a position 1-1.5m inside the blast furnace wall to form a second channel connected to the through-channel; after the second channel is formed, insert the oxygen lance into the second channel, with the front end of the oxygen lance being 0.5-0.6m away from the inside of the blast furnace wall; after the oxygen lance is inserted into the second channel, the blast furnace is supplied with air, and the oxygen lance starts to supply air until the blast furnace taps iron for the first time or the iron mouth burns out automatically.

[0037] In order to better understand the above technical solution, the above technical solution will be described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0038] Example 1

[0039] Please refer to Figures 1 to 4 This embodiment provides a method for opening a furnace using a combined method of a cracker and an oxygen lance for blast furnace air supply recovery.

[0040] For the target blast furnace, an opening machine is used to drill along the iron mouth 30 to a depth of 0.8-1.5 m inside the blast furnace wall 40 to form a first channel 100, such as Figure 1 As shown, the first channel 100 provides a working environment for the fracturing device 200. The 0.8-1.5 m here and the length parameters related to the drilling depth mentioned below all refer to the distance from the inner wall of the furnace wall, and more specifically, the length of the portion of the first channel 100 extending into the furnace. For the opening machine, an extended drill rod is used to drill to a specified depth. After the first channel 100 is drilled, a chisel can also be used to remove the slag iron in the first channel 100 to prevent debris from clogging the channel.

[0041] Afterwards, the fracturing device 200 as a liquid carbon dioxide explosion device is inserted into the first channel 100, and Figure 1 As shown, the front blasting hole 210 of the fracturing device 200 is arranged upward;

[0042] After the fracturing device 200 is inserted into the first channel 100, the mud gun head is rotated to the rear end of the exposed part of the fracturing device 200 from the iron mouth 30, and the mud gun head in front of the blast furnace is used to prevent the fracturing device 200 from popping out and injuring people during the explosion process, thereby improving safety protection.

[0043] After that, the on-site personnel evacuated and remote detonation was carried out. The cracker 200 generated an explosive force of 100-300 MPa upward along the blast hole 210, achieving a large-area penetration of the coke-iron-slag mixed layer 50 between the tuyere 20 and the iron mouth 30, providing a large number of gas channels for the subsequent oxygen injection of the oxygen lance 400. Compared with the traditional oxygen burning method of a single channel between the tuyere 20 and the iron mouth 30, this method greatly improves the connectivity efficiency of the coke-iron-slag mixed layer 50.

[0044] After the blasting is completed, the fracturing device 200 is pulled out.

[0045] To evaluate whether the cracking device 200 has achieved the expected effect, a reference object for inspection, such as a lighter flame or a thin ribbon, is placed at the outer end of the first channel 100. If the lighter flame or the ribbon deflects toward the furnace, it proves that the coke-iron-slag mixed layer 50 between the tuyere 20 and the iron mouth 30 has been penetrated to form the above-mentioned through channel; if the lighter flame points vertically upward or the ribbon is stationary, it means that the coke-iron-slag mixed layer 50 between the tuyere 20 and the iron mouth 30 has not been penetrated to form a through channel, and the above-mentioned operation needs to be continued until the lighter flame or the ribbon deflects toward the furnace to form a through channel.

[0046] A large blast furnace has 3-4 iron openings 30. After each iron opening 30 forms a through passage according to the above steps, a blast furnace front opening machine is used to drill the iron opening 30 again to a position 1-1.5m inside the blast furnace wall 40. Please refer to Figure 2The formed second channel 300 is connected to the through channel, and the second channel 300 provides a use environment for the oxygen gun 400.

[0047] After the second channel 300 is formed, the oxygen lance 400 is inserted into the second channel 300, and the front end of the oxygen lance 400 is 0.5-0.6m away from the inner side of the blast furnace wall 40. Regarding the oxygen lance 400, in some embodiments, please refer to Figure 3 The oxygen lance 400 is provided in a sleeve structure, including an inner tube 410 and an outer tube 420. The inner tube 410 of the oxygen lance 400 is passed through oxygen, and the outer tube 420 is passed through air. When the oxygen lance 400 is inserted into the second hole 300, it is also necessary to use taphole mud to fill the gap between the oxygen lance 400 and the second hole 300.

[0048] After the oxygen lance 400 is inserted into the second channel 300, the blast furnace is supplied with air, and the oxygen lance 400 begins to introduce oxygen and air. In some embodiments, the pressure of oxygen and air is controlled at 0.6-1.0 MPa until the blast furnace taps iron for the first time or the iron mouth 30 burns out automatically.

[0049] Compared with the traditional scheme of "inserting an iron pipe from the tuyere 20 to blow oxygen downward for combustion, inserting an iron pipe from the iron mouth 30 channel to blow oxygen upward for combustion, until a gas channel is formed between the tuyere 20 and the iron mouth 30 channel, and then starting the blast furnace air supply recovery", this embodiment provides a method for opening a furnace using a combined type of fracturing device and an oxygen lance, which limits the position of the fracturing device 200, the size of the explosive force generated by the fracturing device 200, the position of the oxygen lance 400, and the air pressure of the air supply, verifies the through channel through a reference object, improves safety through the blocking of the mud gun head, and provides a complete and feasible scheme, thereby realizing a large area of ​​4-6 meters thick coke iron slag layer between the tuyere 20 and the iron mouth 30 of a large blast furnace. The slag iron formed in front of the tuyere 20 penetrates and drips from the tuyere 20 to the iron mouth 30 relatively smoothly, thus creating good conditions for the first iron tapping of the blast furnace. The shortcomings of artificial oxygen burning penetrating the tuyere 20 and the iron mouth 30, such as long time, poor effect and easy blockage, are effectively improved. At the same time, the phenomenon that the slag iron in the hearth below the tuyere 20 has poor permeability, the tuyere 20 is easy to be damaged, the air adding speed is slow and other phenomena that affect the recovery of the blast furnace after the blast furnace is supplied with air are avoided, and the blast furnace can be quickly restored to full air.

[0050] In some embodiments, the first channel 100 and the second channel 300 are as follows Figure 1 , Figure 2 As shown, it is arranged in an inclined manner, with one end located inside the furnace lower than the other end outside the furnace, and the inclination angle formed with the horizontal plane is controlled within the range of 8°-12°.

[0051] In some embodiments, after a through channel is formed under the condition that the blasting hole 210 is facing upward, the blasting hole 210 is also deviated from the vertical direction by 15°-20° to the left and blasted once according to the operation from forming the first channel 100 to pulling out the fracturator 200, and deviated from the vertical direction by 15°-20° to the right and blasted once according to the operation from forming the first channel 100 to pulling out the fracturator 200, which is intended to further improve the effect of the through-connection between the tuyere 20 and the iron mouth 30. Within the range of 15°-20° deviating from the vertical direction, the two blastings can be better coordinated with the above-mentioned operation of the blasting hole 210 upward, and the parameter range has practical operational guiding significance.

[0052] In some embodiments, the cracker 200 is connected by 2-5 sections, each section is 0.8-1.5 m long. When the cracker 200 is inserted into the first channel 100, the front blasting hole 210 of the cracker 200 is located 0.8-1.5 m inside the blast furnace wall 40. Regarding the cracker 200, the part extending into the furnace has a safety protection function, which can ensure that the front end inserted into the furnace wall will not naturally detonate prematurely in a high-temperature enclosed space exceeding 200°C.

[0053] Example 2

[0054] Based on the combined furnace opening method using a cracker and an oxygen lance provided in Example 1, this embodiment further defines the first channel 100 in combination with different blast furnaces.

[0055] For 1000-2000m 3 For blast furnaces, the drilling machine drills to a depth of 0.8m inside the 40m of the blast furnace wall.

[0056] For 2000-3000m 3 For blast furnaces, the drilling machine drills to a depth of 1.0m inside the 40m of the blast furnace wall.

[0057] For 3000-4000m 3 For blast furnaces, the drilling machine drills to a depth of 1.2m inside the 40m of the blast furnace wall.

[0058] For 4000m 3 For blast furnaces above 40, the drilling machine drills to a depth of 1.4-1.5 m inside the blast furnace wall 40.

[0059] It should be pointed out that the above-mentioned dimensions of 0.8 m, 1.0 m, 1.2 m, and 1.4-1.5 m all refer to the length of the first channel 100 located on the inner wall of the furnace wall.

[0060] Example 3

[0061] Based on the combined furnace opening method using a cracker and an oxygen lance provided in Example 1, this embodiment defines the cracker 200 used in the method for different blast furnaces.

[0062] For 1000-2000m 3 For blast furnaces, two-stage fracturing devices 200 with each stage being 1.4-1.5m long are used for fracturing blasting.

[0063] For 2000-3000m 3 For blast furnaces, three-stage fracturing devices 200 with each stage being 1.2-1.3m long are used for fracturing blasting.

[0064] For 3000-4000m 3 For blast furnaces, four-stage fracturing devices 200 with a length of 1.0-1.2 m per stage are used for fracturing blasting.

[0065] For 4000m 3 The above blast furnaces are subjected to fission blasting using a 5-stage fracturing device 200, each with a length of 0.8-1.1 m.

[0066] Example 4

[0067] Based on the combined furnace opening method using a cracker and an oxygen lance provided in Example 1, this example limits the magnitude of the explosive force generated by the cracker 200 in combination with different blast furnaces.

[0068] For 1000-2000m 3 For a blast furnace, under the condition of remote detonation, an explosion force of not less than 150 MPa is generated upward at the blast hole 210.

[0069] For 2000-3000m 3 For a blast furnace, under the condition of remote detonation, an explosion force of not less than 180 MPa is generated upward at the blast hole 210.

[0070] For 3000-4000m 3 For a blast furnace, under the condition of remote detonation, an explosion force of not less than 200 MPa is generated upward at the blast hole 210.

[0071] For 4000m 3 The above blast furnace, under the condition of remote detonation, generates an upward explosion force of not less than 250 MPa at the blast hole 210 .

[0072] Although the preferred embodiments of the present invention have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0073] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A method for opening a furnace using a combined cracker and oxygen lance, characterized in that: The method comprises: Use an opening machine to drill along the iron mouth to a depth of 0.8-1.5m inside the blast furnace wall to form the first channel; After the first hole is formed, a fracturing device is inserted into the first hole, with the front end blasting hole of the fracturing device facing upwards; After the fracturing device is inserted into the first hole, the mud gun head is turned to the rear end of the exposed part of the fracturing device from the iron mouth, and remote detonation is performed to generate an explosive force of 100-300 MPa upward at the blasting hole, and the fracturing device is pulled out after the blasting is completed; After the fracturing device is pulled out, a reference object for inspection is placed at the first channel, and if a through channel is not formed between the inspection air port and the iron mouth, the operation from forming the first channel to pulling out the fracturing device is repeated until the inspection air port and the iron mouth form the through channel; After the through passage is formed at each iron mouth of the blast furnace, an opening machine is used to drill again along the iron mouth to a position 1-1.5 m inside the furnace wall of the blast furnace to form a second channel communicating with the through passage; After the second channel is formed, an oxygen lance is inserted into the second channel, with the front end of the oxygen lance being 0.5-0.6 m away from the inner side of the blast furnace wall; After the oxygen lance is inserted into the second hole, the blast furnace supplies air and the oxygen lance starts to supply air until the blast furnace taps iron for the first time or the iron mouth burns out automatically.

2. The method according to claim 1, characterized in that After the through channel is formed under the condition that the blasting hole is facing upward, the method further includes deviating the blasting hole to the left by 15°-20° and to the right by 15°-20° from the vertical direction to perform a blasting operation from forming the first channel to pulling out the fracturing device.

3. The method according to claim 1, characterized in that The method of using an opening machine to drill along the iron mouth to a depth of 0.8-1.5 m inside the blast furnace wall to form a first channel includes: For 1000m 3 Above and less than 2000m 3 The blast furnace, the opening machine drills to a depth of 0.8m inside the blast furnace wall; For 2000m 3 Above and less than 3000m 3 The blast furnace, the opening machine drills to a depth of 1.0 m inside the blast furnace wall; For 3000m 3 Above and less than 4000m 3 The blast furnace, the opening machine drills to a depth of 1.2 m inside the blast furnace wall; For 4000m 3 In the above blast furnace, the opening machine drills to a depth of 1.4-1.5m inside the blast furnace wall.

4. The method according to claim 3, characterized in that After forming the first hole and before inserting the fracturing device into the first hole, the method further includes: Use a brazing tool to remove the slag and iron in the first hole.

5. The method according to claim 1, characterized in that The cracker is connected by 2-5 sections, each section is 0.8-1.5m long; the cracker is inserted into the first channel, and the front blasting hole of the cracker is located at 0.8-1.5m inside the blast furnace wall.

6. The method according to claim 5, characterized in that For 1000m 3 Above and less than 2000m 3 The blast furnace is subjected to cracking blasting by using the cracking device with two sections, each section being 1.4-1.5 m long; For 2000m 3 Above and less than 3000m 3 The blast furnace is subjected to cracking blasting by using the cracking device with three sections, each section being 1.2-1.3 m long; For 3000m 3 Above and less than 4000m 3 The blast furnace is subjected to fracturing blasting by using the fracturing device having 4 sections, each section having a length of 1.0-1.2 m; For 4000m 3 The above-mentioned blast furnace adopts 5-stage crackers, each with a length of 0.8-1.1m, for cracking blasting.

7. The method according to claim 1, characterized in that For 1000m 3 Above and less than 2000m 3 The blast furnace, under the condition of the remote detonation, generates an explosion force of not less than 150 MPa upward at the blast hole; For 2000m 3 Above and less than 3000m 3 The blast furnace, under the condition of the remote detonation, generates an explosion force of not less than 180 MPa upward at the blast hole; For 3000m 3 Above and less than 4000m 3 The blast furnace, under the condition of the remote detonation, generates an explosion force of not less than 200 MPa upward at the blast hole; For 4000m 3 The above-mentioned blast furnace, under the condition of the remote detonation, generates an explosion force of not less than 250MPa upwards at the blasting hole.

8. The method according to claim 1, characterized in that The reference object includes a lighter flame or a ribbon, which is placed at the outer end of the first channel. If the lighter flame or the ribbon is tilted toward the furnace, the through channel is formed; if the lighter flame is vertically upward or the ribbon is stationary, the through channel has not yet been formed between the air port and the iron mouth, and the operation from forming the first channel to pulling out the cracking device is repeated until the lighter flame or the ribbon is tilted toward the furnace.

9. The method according to claim 1, characterized in that Inserting the oxygen lance into the second hole includes: filling the gap between the oxygen lance and the second hole with taphole mud; The oxygen lance is arranged in a sleeve structure, with oxygen passing through an inner tube of the oxygen lance and air passing through an outer tube.

10. The method according to claim 9, characterized in that The oxygen lance starts to supply gas, including: the oxygen lance starts to supply oxygen and air, and the pressures of the oxygen and the air are controlled at 0.6-1.0 MPa.

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