Operation method for discharging low-temperature slag iron at iron notch

Abstract

The invention belongs to the technical field of blast furnace ironmaking, and discloses an operation method for discharging low-temperature slag iron at an iron notch, which comprises the following steps: S1, detecting the temperature of molten iron discharged at the iron notch, and when the temperature of the molten iron is lower than a first preset temperature, conducting a closed iron notch part by using a tapping machine; s2, the tapping machine is withdrawn, an oxygen burning pipe and a compressed air blowing pipe are simultaneously introduced into the iron notch, oxygen is introduced into the oxygen burning pipe, and the oxygen burning pipe is ignited until the iron notch is completely communicated; s3, oxygen introduction is stopped, and the oxygen burning pipe is withdrawn; s4, combustion-supporting powder is added into the compressed air blowing pipe, and compressed air is introduced; s5, a compressed air blowing pipe is gradually pushed into the iron notch until the length of the compressed air blowing pipe outside the iron notch is equal to the safe length; and S6, replacing a standby compressed air blowing pipe, introducing the compressed air into the iron notch, and repeating the steps S4 and S5 until all slag iron is discharged from the iron notch. According to the operation method, the low-temperature slag iron can be effectively discharged at low production cost, and the safety is good.

Description

Technical Field

[0001] The invention relates to the technical field of blast furnace ironmaking, in particular to an operating method for discharging low-temperature slag iron from an iron mouth. Background Art

[0002] The slag generated by blast furnace smelting needs to be regularly discharged from the blast furnace hearth through the iron mouth together with the molten iron. In the hearth, the slag and the molten iron are in a mixed state. When the hearth slag iron has a higher temperature, the slag iron can be discharged smoothly from the hearth area; when the hearth slag iron temperature is low, the fluidity of the slag iron drops sharply, and it is more difficult to discharge from the iron mouth. Even if the slag iron can be discharged from the iron mouth, when it flows from the iron mouth to the main ditch, the slag iron will cool down more quickly when it contacts the atmosphere. After the slag iron is separated from the main ditch and the molten iron, the slag iron flows into the slag ditch, which will cause the slag ditch to be discharged unsmoothly. It is necessary to manually organize the dredging of the slag ditch, which is labor-intensive and risky. Moreover, when the temperature of the blast furnace slag iron is low, if the low-temperature slag iron is not discharged from the hearth in time, it is very easy to cause the hearth to freeze, and it is impossible to make room for the fuel to fall into the hearth, causing major process accidents.

[0003] The existing blast furnace smelting part adopts multiple-frequency opening and blocking of the iron mouth to discharge low-temperature slag and iron. This operation method leads to obvious loss of materials such as drill rods in front of the furnace, a large increase in consumption, and greatly increases production costs. Moreover, even if the iron mouth is opened and blocked, the temperature of the slag and iron is still low, which leads to poor slag discharge from the slag ditch and freezing of the furnace cylinder. Summary of the invention

[0004] The purpose of the present invention is to provide an operating method for discharging low-temperature slag from the iron mouth, which can solve the problem that the low-temperature slag is difficult to be discharged from the iron mouth in the existing blast furnace smelting, resulting in poor slag discharge in the slag ditch and freezing of the furnace, resulting in high labor intensity and high operation risk in unblocking the slag ditch, and the frequent opening and blocking of the iron mouth greatly increases the production cost.

[0005] To achieve this object, the present invention adopts the following technical solutions:

[0006] Provided is an operation method for discharging low-temperature slag from an iron mouth, which is used to discharge low-temperature slag in a blast furnace, comprising the following steps:

[0007] S1, detecting the temperature of the molten iron discharged from the iron mouth, and when the molten iron temperature is lower than a first preset temperature, using an opening machine to open a closed iron mouth portion;

[0008] S2, exit the tapping machine, use the oxygen burning pipe and the compressed air blowing pipe to simultaneously pass oxygen into the tapping, pass oxygen into the oxygen burning pipe and ignite the oxygen burning pipe until the tapping is fully conductive;

[0009] S3, closing the oxygen supply and exiting the oxygen burning tube;

[0010] S4, adding combustion-supporting powder into the compressed air blowing pipe and introducing compressed air;

[0011] S5, gradually push the compressed air blowing pipe into the tap hole until the length of the compressed air blowing pipe outside the tap hole is equal to the safety length;

[0012] S6, replace the spare compressed air blowing pipe and pass it into the tap hole, repeat the above steps S4 and S5 until all the slag and iron are discharged from the tap hole.

[0013] As an optional embodiment of the present invention, in S3, adding combustion-supporting powder into the compressed air blowing pipe specifically includes the following steps:

[0014] The combustion-supporting powder to be added is divided into multiple portions, and the adding operations are performed separately for multiple times. During each adding operation, one portion of the combustion-supporting powder is added into the compressed air blowing pipe. Moreover, in the interval between adjacent adding operations, one end of the compressed air blowing pipe is lifted away from the iron mouth, so that the combustion-supporting powder in the compressed air blowing pipe slides toward the other end of the compressed air blowing pipe.

[0015] As an optional implementation manner of the present invention, a waiting time is set between adjacent adding operations, and the waiting time is 3 minutes to 5 minutes.

[0016] As an optional embodiment of the present invention, the compressed air blowing pipe is provided with a regulating valve, and the regulating valve is used to adjust the flow rate of the compressed air; in S4, the introduction of compressed air specifically includes the following steps:

[0017] The opening of the regulating valve is adjusted to a first opening, and the opening of the regulating valve is gradually increased until flame blows out of the iron mouth; then, the opening of the regulating valve is gradually reduced until no flame blows out of the iron mouth, at which time, the opening of the regulating valve is a second opening, and the regulating valve is maintained at the second opening.

[0018] As an optional implementation manner of the present invention, in said S5, the following steps are also included:

[0019] The regulating valve is adjusted and the slag blown out of the iron mouth is observed to maintain the splashing distance of the slag at 1m to 3m; wherein, when the splashing distance of the slag is less than 1m, the opening of the regulating valve is made greater than the second opening; when the splashing distance of the slag is greater than 3m, the opening of the regulating valve is made less than the second opening.

[0020] As an optional embodiment of the present invention, the operating method further includes performing an operation of increasing the furnace temperature, and the operation of increasing the furnace temperature specifically includes the following steps:

[0021] S101, setting the daily control temperature of slag iron to T1-T2;

[0022] S102. When the temperature of the molten iron discharged from the iron mouth is lower than T1, the fuel of the blast furnace is increased to improve the fuel ratio according to the difference between the molten iron temperature and T1, wherein the improved fuel ratio is positively correlated with the difference; and, when the temperature of the molten iron is lower than a first preset temperature, S1 to S6 are executed simultaneously, wherein the first preset temperature is less than T1, and the difference between the first preset temperature and T1 is a second preset temperature.

[0023] As an optional implementation of the present invention, while performing the furnace temperature raising operation, it also includes performing a wind reduction heat storage operation, and the wind reduction heat storage operation specifically includes the following steps:

[0024] When the temperature of the molten iron discharged from the taphole is lower than T1, the blast furnace air volume is reduced according to the difference between the molten iron temperature and T1, wherein the reduced air volume is positively correlated with the temperature difference.

[0025] As an optional embodiment of the present invention, a through addition port is opened in the middle of the tube body of the compressed air blowing pipe, and the compressed air blowing pipe also includes a covering member detachably connected to the tube body, and the covering member can block the addition port, and the addition port is used to add combustion-supporting powder.

[0026] As an optional embodiment of the present invention, the blast furnace is provided with a slag skimmer, the slag skimmer is used to separate slag iron from molten iron, and the slag skimmer is arranged in the main groove outside the iron mouth;

[0027] In the step S5, the safety length is equal to the distance between the iron mouth and the slag skimmer.

[0028] As an optional implementation manner of the present invention, the lengths of the oxygen burning pipe and the compressed air blowing pipe are both 20m to 30m.

[0029] Beneficial effects of the present invention:

[0030] The operation method of the iron mouth for discharging low-temperature slag iron provided by the present invention first uses an opening machine to partially conduct the closed iron mouth to prevent the iron mouth that is fully conducted in advance from flowing out low-temperature slag iron, thereby causing the low-temperature slag iron to block the iron mouth channel and cannot continue to discharge. Then, the oxygen in the oxygen burning pipe meets the sparks existing in the partially conducted iron mouth and burns to make the iron mouth quickly reach a fully conducted state. The introduction and withdrawal of the oxygen burning pipe are relatively convenient, and the operation can be quickly operated to avoid the iron mouth being blocked by low-temperature slag iron. The combustion-supporting powder blown by the compressed air blowing pipe encounters the slag iron inside the furnace to produce a violent reaction, heats the slag iron discharged from the iron mouth, increases its temperature, improves its fluidity, and can quickly flow out of the iron mouth, avoiding the iron mouth from sticking and blocking, thereby achieving the effective discharge of low-temperature slag iron. Since the temperature of the slag iron flowing out of the iron mouth is relatively high, the cooling of the slag iron after contacting the atmosphere will not cause the slag groove to discharge poorly, avoiding the problems of high labor intensity and high operation risk caused by artificial organization to dredge the slag groove. At the same time, the slag iron that quickly flows out of the iron mouth frees up fuel descending space for the furnace, avoiding major process accidents caused by the freezing of the furnace. Compared with the drill pipe in front of the furnace, the compressed air blowing pipe is low in cost, thus avoiding a significant increase in production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a flow chart of an operation method for discharging low-temperature slag from an iron mouth provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0032] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] In the description of the present invention, it should be noted that the orientations or positional relationships indicated by the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc. are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. Among them, the terms "first position" and "second position" are two different positions, and the first feature "above", "above" and "above" the second feature include the first feature being directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. The first feature "below", "below" and "below" the second feature include the first feature being directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0034] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0035] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0036] Embodiment 1

[0037] like Figure 1 As shown, the first embodiment of the present invention provides an operating method for discharging low-temperature slag from an iron mouth, which is used to discharge low-temperature slag in a blast furnace.

[0038] The operation method of tapping low-temperature slag iron includes the following steps:

[0039] S1. Detect the temperature of the molten iron discharged from the iron mouth. When the temperature of the molten iron is lower than the first preset temperature, use an opening machine to partially conduct a closed iron mouth. In this step, when the temperature of the molten iron is lower than the first preset temperature, it can be judged that the slag iron in the furnace is in an undertemperature state. At this time, the following steps need to be performed to assist in discharging the slag iron. First, select an unused iron mouth. The opening machine uses a drill with a diameter of 60mm to 65mm to drill the iron mouth. When a red dot appears at the iron mouth, it indicates that sparks are blown out of the iron mouth channel. Alternatively, the conduction state can be judged based on the predetermined iron mouth depth. When the drilling depth of the drill bit is 4 / 5 of the iron mouth depth, or the length of the drill bit from the iron mouth through point is 200mm to 300mm, stop drilling the iron mouth to keep the iron mouth in a partially conductive state.

[0040] S2. Exit the tapping machine, use the oxygen burning pipe and the compressed air blowing pipe to simultaneously pass oxygen into the iron mouth, pass oxygen into the oxygen burning pipe and ignite the oxygen burning pipe until the iron mouth is fully conductive; in this step, connect the other end of the oxygen burning pipe away from the iron mouth to the medium-pressure oxygen supply equipment, and the other end of the compressed air blowing pipe away from the iron mouth to the compressed air supply equipment. First, oxygen is passed into the oxygen burning pipe, and sparks will sputter at the red spots that appear at the partially conductive iron mouth. The sputtered sparks will encounter the medium-pressure oxygen and be ignited, and the iron mouth will be quickly conductive through combustion. During this process, the compressed air blowing pipe is idle.

[0041] S3. After all the iron mouths are connected, close the oxygen supply and exit the oxygen burning tube.

[0042] S4. Add combustion-supporting powder into the compressed air blowing pipe and introduce compressed air; the combustion-supporting powder enters the iron mouth channel under the blowing of compressed air, and violently reacts with the slag iron inside the furnace, heating the slag iron discharged from the iron mouth, so that the slag iron temperature increases, the fluidity becomes better, and can flow out of the iron mouth quickly, avoiding adhesion and blockage of the iron mouth.

[0043] S5. The compressed air blowing pipe is gradually pushed into the iron mouth. During this process, the combustion of the combustion-supporting powder continues to heat the slag iron in the iron mouth channel. At the same time, the compressed air blowing pipe is also continuously burning in the iron mouth channel until the length of the compressed air blowing pipe outside the iron mouth is equal to the safe length. At this time, since the distance between the end of the compressed air blowing pipe and the iron mouth is close, the safety of continuing to push is poor.

[0044] S6, replace the spare compressed air blowing pipe and pass it into the tap hole, repeat the above steps S4 and S5 until all the slag and iron are discharged from the tap hole. This embodiment does not limit the number of replacements.

[0045] The operating method for discharging low-temperature slag from the iron mouth provided in the first embodiment of the present invention first uses an opening machine to partially conduct the closed iron mouth to prevent the iron mouth that is fully conducted in advance from flowing out low-temperature slag, which causes the low-temperature slag to block the iron mouth channel and cannot be discharged further. Then, the oxygen in the oxygen burning pipe meets the sparks in the partially conducted iron mouth and burns to make the iron mouth quickly reach a fully conducted state. The introduction and withdrawal of the oxygen burning pipe are relatively convenient and can be operated quickly to avoid the iron mouth being blocked by low-temperature slag. The combustion-supporting powder blown by the compressed air blowing pipe reacts violently with the slag inside the furnace, heating the slag discharged from the iron mouth, increasing the temperature of the slag, improving its fluidity, and allowing it to quickly flow out of the iron mouth, avoiding adhesion and blockage of the iron mouth, thereby achieving effective discharge of low-temperature slag. Since the temperature of the slag flowing out of the iron mouth is relatively high, the cooling of the slag after contact with the atmosphere will not cause the slag ditch to be discharged unsmoothly, thus avoiding the problems of high labor intensity and high operation risk caused by manually organizing the dredging of the slag ditch. At the same time, the slag flowing out of the iron mouth quickly frees up space for the fuel to fall into the furnace, thus avoiding major process accidents caused by the freezing of the furnace. Compared with the drill rod in front of the furnace, the compressed air blowing pipe has a low cost, which avoids a significant increase in production costs.

[0046] The combustion-supporting powder is a flammable powder that is easy to burn and can quickly increase the temperature of the slag iron in the furnace. For example, before S4, aluminum powder and bag dust ash are evenly mixed in a ratio of 1:1 as combustion-supporting powder. Bag dust ash is a kind of dust collected by a bag dust collector at a blast furnace production site. It contains about 30% iron powder, 30% coke powder, and other ash. Bag dust ash is easy to obtain and does not require additional purchase, which will not increase production costs, and at the same time achieve environmental protection effects. It should be noted that before mixing, the bag dust ash must be in a cold state at room temperature.

[0047] This embodiment does not limit the first preset temperature, and the first preset temperature can be set according to the furnace capacity, production process, etc. Generally speaking, for 2000m 3 ~4000m 3 For a blast furnace with a furnace capacity of 2000MW, when the temperature of molten iron drops to 1450℃, it means that the heat in the furnace is seriously insufficient and the slag iron will condense very quickly when it flows out. At this time, it can be judged that the slag iron is in an under-temperature state.

[0048] In S3, adding combustion-supporting powder into the compressed air blowing pipe specifically includes the following steps: dividing the combustion-supporting powder to be added into multiple portions, and performing adding operations separately for multiple times, adding one portion of the combustion-supporting powder into the compressed air blowing pipe during each adding operation, and, in the interval between adjacent adding operations, lifting one end of the compressed air blowing pipe away from the iron mouth, so that the combustion-supporting powder in the compressed air blowing pipe slides toward the other end of the compressed air blowing pipe under the action of gravity, avoiding accumulation in the front section of the compressed air blowing pipe and affecting the reaction effect.

[0049] A waiting time is set between adjacent adding operations, and the waiting time is 3 minutes to 5 minutes, so that the combustion-supporting powder added each time can be fully preheated, and the subsequent reaction is relatively fast and intense.

[0050] A regulating valve is provided on the compressed air blowing pipe, and the regulating valve is used to adjust the flow rate of compressed air; in S4, the introduction of compressed air specifically includes the following steps: adjusting the opening of the regulating valve to a first opening, and gradually increasing the opening of the regulating valve until a flame blows out of the iron mouth; then, gradually reducing the opening of the regulating valve until no flame blows out of the iron mouth, at this time, the opening of the regulating valve is a second opening, and the regulating valve is maintained at the second opening.

[0051] Exemplarily, the first opening of the regulating valve is set to 1%, and the adjustment gradient is 1% each time, so that the flow rate of compressed air is as small as possible, the combustion-supporting powder can achieve a sufficient combustion reaction, and the slag iron near the iron mouth is fully heated. As flames blow out of the iron mouth, it means that the temperature in the iron mouth channel is already high enough, and the melting speed of the compressed air blowing pipe needs to be controlled. At this time, the flow rate of compressed air needs to be controlled slightly faster to adjust the gradient to 1% to 5% to reduce the opening of the regulating valve until no flame blows out of the iron mouth. The opening of the regulating valve is maintained at the second opening in this state to push the compressed air blowing pipe.

[0052] In S5, the discharge method also includes the following steps: adjusting the regulating valve and observing the slag iron blown out of the iron mouth, keeping the splashing distance of the slag iron at 1m to 3m; wherein, when the splashing distance of the slag iron is less than 1m, the opening of the regulating valve is greater than the second opening to increase the flow rate of compressed air and accelerate the combustion and heating effect of the combustion-supporting powder on the slag iron; when the splashing distance of the slag iron is greater than 3m, the opening of the regulating valve is less than the second opening, the flow rate of compressed air is reduced, and the combustion and heating effect of the combustion-supporting powder on the slag iron is slowed down. Since the opening of the regulating valve has been adjusted to the second opening in S4, the combustion and heating of the slag iron by the combustion-supporting powder in the compressed air blowing pipe can be maintained at this time, and the burning flame can be prevented from spraying out of the iron mouth to cause excessive slag iron splashing, which has a safety hazard on the one hand and affects the normal discharge of slag iron and flows into the main groove outside the iron mouth on the other hand. By observing the splashing distance of the slag iron, the opening of the regulating valve is adaptively adjusted on the basis of the second opening, thereby adjusting the flow rate of compressed air to keep the splashing distance of the slag iron at 1m to 3m.

[0053] A through addition port is provided in the middle of the body of the compressed air blowing pipe. The compressed air blowing pipe also includes a cover detachably connected to the body, which can block the addition port, and the addition port is used to add combustion-supporting powder. The cover is made of a metal film and can be used for a long time in a high temperature environment. When performing the addition operation, open the cover to expose the addition port, and use a funnel to add combustion-supporting powder from the addition port into the compressed air blowing pipe. The funnel can prevent the powder from scattering. When the addition operation is completed, use the cover to re-block the addition port to ensure that the compressed air will not leak.

[0054] In order to improve the convenience of disassembly of the cover, a buckle structure can be provided between the cover and the tube body, which is easy to disassemble and has good sealing performance. The buckle structure can be provided with reference to the prior art, and this embodiment will not be described in detail here.

[0055] The blast furnace is provided with a slag skimmer, which is used to separate slag iron from molten iron, and the slag skimmer is arranged in the main groove outside the iron mouth; in S5, the safety length is equal to the distance between the iron mouth and the slag skimmer. The structure and setting distance of the slag skimmer can be set with reference to the prior art, and this embodiment does not make specific restrictions.

[0056] Optionally, the length of the oxygen-burning pipe and the compressed air blowing pipe are both 20m to 30m. When the oxygen-burning pipe is within this length range, it can ensure that the oxygen-burning pipe can quickly pass oxygen and form a combustion flame to conduct the iron mouth, avoiding the iron mouth in a partially conductive state from being re-blocked by low-temperature slag; when the length of the compressed air blowing pipe is within this range, on the one hand, it can ensure that the pressure loss of the compressed air will not be too large, and on the other hand, it can ensure that there is enough length for pushing, reducing the number of replacements of the compressed air blowing pipe. Both the oxygen-burning pipe and the compressed air blowing pipe use metal pipes with an aperture of 12mm to 24mm. The specific aperture and length can be selected according to production needs.

[0057] Embodiment 2

[0058] Embodiment 2 of the present invention provides an operation method for discharging low-temperature slag from a taphole, which is used to discharge low-temperature slag from a blast furnace. The operation method for discharging low-temperature slag from a taphole includes S1-S6 in the above embodiment 1. In addition, the operation method of the embodiment 2 also includes performing a furnace temperature increase operation, and the furnace temperature increase operation specifically includes the following steps:

[0059] S101, setting the daily control temperature of slag iron to T1-T2;

[0060] S102. When the temperature of the molten iron discharged from the iron mouth is lower than T1, it indicates that the furnace temperature needs to be increased; at this time, according to the difference between the molten iron temperature and T1, the fuel of the blast furnace is increased to increase the fuel ratio, wherein the increased fuel ratio is positively correlated with the difference; illustratively, for every 10°C decrease in the difference between the molten iron temperature discharged from the iron mouth and T1, the fuel of the blast furnace is increased to increase the fuel ratio by 3kg / t to 5kg / t, so as to achieve the effect of supplementary heat. The temperature of the molten iron discharged from the iron mouth decreases more, and the increased fuel ratio needs to be correspondingly larger. The fuel ratio is the sum of the values ​​of all fuels such as coke, pulverized coal, and heavy oil consumed by the blast furnace to produce each ton of molten iron. The increase in the fuel ratio is conducive to combustion, thereby increasing the furnace temperature, and the slag iron temperature is increased by increasing the furnace temperature.

[0061] In this step, when the temperature of the molten iron is lower than the first preset temperature, S1 to S6 are performed simultaneously, wherein the first preset temperature is less than T1, and the difference between the first preset temperature and T1 is the second preset temperature. Since the increase in furnace temperature requires a long reaction time, at least one smelting cycle of the blast furnace is required to reflect the supplementary heat effect. Therefore, when the temperature of the molten iron continues to decrease, the slag iron needs to be heated and heated more quickly and directly. Exemplarily, the second preset temperature is 50°, that is, the temperature of the molten iron discharged from the iron mouth at this time is lower than the lower limit of the daily control temperature of 50°C. At this time, it is necessary to use S1-S6 in Example 1 to heat the slag iron more quickly and directly while increasing the furnace temperature to supplement the heat.

[0062] Optionally, while performing the operation of increasing the furnace temperature, it also includes performing an operation of reducing wind and storing heat, which specifically includes the following steps: when the temperature of the molten iron discharged from the iron mouth is lower than T1, the blast furnace air volume is reduced according to the difference between the molten iron temperature and T1, wherein the reduced air volume is positively correlated with the temperature difference. That is, the lower the molten iron temperature, the more the blast furnace air volume is reduced. While consuming fuel to increase the furnace temperature, the blast furnace air reduction operation is also performed to increase the heat storage capacity of the furnace, further achieving the effect of maintaining and increasing the furnace temperature, making the discharge of slag iron faster and more reliable.

[0063] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, various obvious changes, readjustments and substitutions can be made without departing from the protection scope of the present invention. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. An operating method for discharging low-temperature slag from an iron mouth, which is used to discharge low-temperature slag in a blast furnace, and is characterized in that: The following steps are involved: S1, detecting the temperature of the molten iron discharged from the iron mouth, and when the molten iron temperature is lower than a first preset temperature, using an opening machine to open a closed iron mouth portion; S2, exit the tapping machine, use the oxygen burning pipe and the compressed air blowing pipe to simultaneously pass oxygen into the tapping, pass oxygen into the oxygen burning pipe and ignite the oxygen burning pipe until the tapping is fully conductive; S3, closing the oxygen supply and exiting the oxygen burning tube; S4, adding combustion-supporting powder into the compressed air blowing pipe and introducing compressed air; S5, gradually push the compressed air blowing pipe into the tap hole until the length of the compressed air blowing pipe outside the tap hole is equal to the safety length; S6. Replace the spare compressed air blowing pipe and pass it into the tap hole, repeat S4 and S5 until all the slag and iron are discharged from the tap hole.

2. The method for discharging low-temperature slag from an iron mouth according to claim 1, characterized in that: In S3, adding combustion-supporting powder into the compressed air blowing pipe specifically comprises the following steps: The combustion-supporting powder to be added is divided into multiple portions, and the adding operations are performed separately for multiple times. During each adding operation, one portion of the combustion-supporting powder is added into the compressed air blowing pipe. Moreover, in the interval between adjacent adding operations, one end of the compressed air blowing pipe is lifted away from the iron mouth, so that the combustion-supporting powder in the compressed air blowing pipe slides toward the other end of the compressed air blowing pipe.

3. The method for discharging low-temperature slag from an iron mouth according to claim 2, characterized in that: A waiting time is set between adjacent adding operations, and the waiting time is 3 minutes to 5 minutes.

4. The method for discharging low-temperature slag from an iron mouth according to claim 1, characterized in that: The compressed air blowing pipe is provided with a regulating valve, and the regulating valve is used to adjust the flow rate of the compressed air; in S4, the introduction of compressed air specifically includes the following steps: The opening of the regulating valve is adjusted to a first opening, and the opening of the regulating valve is gradually increased until flame blows out of the iron mouth; then, the opening of the regulating valve is gradually reduced until no flame blows out of the iron mouth, at which time, the opening of the regulating valve is a second opening, and the regulating valve is maintained at the second opening.

5. The method for discharging low-temperature slag from an iron mouth according to claim 4, characterized in that: In said S5, the following steps are also included: The regulating valve is adjusted and the slag blown out of the iron mouth is observed to maintain the splashing distance of the slag at 1m to 3m; wherein, when the splashing distance of the slag is less than 1m, the opening of the regulating valve is made greater than the second opening; when the splashing distance of the slag is greater than 3m, the opening of the regulating valve is made less than the second opening.

6. The method for discharging low-temperature slag from an iron mouth according to claim 1, characterized in that: The operation method further includes performing an operation of increasing the furnace temperature, and the operation of increasing the furnace temperature specifically includes the following steps: S101, setting the daily control temperature of slag iron to T1-T2; S102. When the temperature of the molten iron discharged from the iron mouth is lower than T1, the fuel of the blast furnace is increased to improve the fuel ratio according to the difference between the molten iron temperature and T1, wherein the improved fuel ratio is positively correlated with the difference; and, when the temperature of the molten iron is lower than a first preset temperature, S1 to S6 are executed simultaneously, wherein the first preset temperature is less than T1, and the difference between the first preset temperature and T1 is a second preset temperature.

7. The method for discharging low-temperature slag from an iron mouth according to claim 6, characterized in that: While performing the furnace temperature raising operation, an air reduction and heat storage operation is also performed, and the air reduction and heat storage operation specifically includes the following steps: When the temperature of the molten iron discharged from the taphole is lower than T1, the blast furnace air volume is reduced according to the difference between the molten iron temperature and T1, wherein the reduced air volume is positively correlated with the temperature difference.

8. The method for discharging low-temperature slag from an iron mouth according to any one of claims 1 to 7, characterized in that: A through adding port is provided in the middle of the tube body of the compressed air blowing tube. The compressed air blowing tube also includes a covering member detachably connected to the tube body, the covering member can block the adding port, and the adding port is used for adding combustion-supporting powder.

9. The method for discharging low-temperature slag from an iron mouth according to any one of claims 1 to 7, characterized in that: The blast furnace is provided with a slag skimmer, which is used to separate slag iron from molten iron, and the slag skimmer is arranged in the main groove outside the iron mouth; In the step S5, the safety length is equal to the distance between the iron mouth and the slag skimmer.

10. The method for discharging low-temperature slag from an iron mouth according to any one of claims 1 to 7, characterized in that: The lengths of the oxygen burning pipe and the compressed air blowing pipe are both 20m to 30m.

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