CN114774600A - Process method for centralized alkali discharge of blast furnace - Google Patents
Process method for centralized alkali discharge of blast furnace Download PDFInfo
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- CN114774600A CN114774600A CN202210459045.XA CN202210459045A CN114774600A CN 114774600 A CN114774600 A CN 114774600A CN 202210459045 A CN202210459045 A CN 202210459045A CN 114774600 A CN114774600 A CN 114774600A
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- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21B—MANUFACTURE OF IRON OR STEEL
- C21B5/00—Making pig-iron in the blast furnace
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- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21B—MANUFACTURE OF IRON OR STEEL
- C21B2300/00—Process aspects
- C21B2300/04—Modeling of the process, e.g. for control purposes; CII
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- Waste-Gas Treatment And Other Accessory Devices For Furnaces (AREA)
Abstract
The invention discloses a process method for removing alkali in a blast furnace in a centralized way. Should utilize blast furnace periodic maintenance opportunity, reduce the stockline to the furnace shaft lower part after, carry out the alkali of arranging, include the following step: 1) compiling and determining a periodic blast furnace maintenance plan according to the alkali discharge requirement of the process; 2) when the blast furnace maintenance plan is determined to carry out maintenance according to the step 1), reducing a stockline to the lower part of a furnace body, and carrying out concentrated alkali discharge operation; 3) and processing the slightly thickened surface. The method can effectively carry out centralized alkali removal on the blast furnace by utilizing the scheduled maintenance opportunity, can reduce the frequency of daily alkali removal, reduces the adverse effect of the daily alkali removal on the production of the blast furnace, and makes up the deficiency of the daily alkali removal.
Description
Technical Field
The invention relates to the technical field of smelting, in particular to a process method for intensively discharging alkali in a blast furnace.
Background
Zn has similar characteristics to K, Na in blast furnace ironmaking production, and blast furnace alkali metal mainly refers to Zn, K and Na. K has a melting point of 63.25 ℃ and a boiling point of 758 ℃, Na has a melting point of 97.83 ℃ and a boiling point of 883 ℃, Zn has a melting point of about 419 ℃ and a boiling point of 907 ℃. After the alkali metal is charged into the furnace along with the furnace material and reaches a high-temperature region, one part of the alkali metal enters the furnace slag and is discharged out of the furnace, and the other part of the alkali metal is reduced into a simple substance. The alkali metal reduced into the simple substance is easy to gasify and then rises along with coal gas because of low boiling point, part of the alkali metal reaching the low temperature region is discharged out of the blast furnace along with coal gas ash in the form of the simple substance and compounds, the rest part of the alkali metal is attached to the furnace wall to form furnace accretions or is attached to furnace burden and continuously descends along with the furnace burden to reach the high temperature region, and the alkali metal is reduced and gasified again to rise, so that the circulation process of the alkali metal in the blast furnace is formed. Because the alkali metal has the property of cyclic enrichment, the concentration of the enrichment in the blast furnace is far higher than that of the alkali metal in the charging materials, thereby bringing great harm to the production of the blast furnace, which is mainly shown in the following steps: the coke gasification reactivity is catalyzed to cause the strength of the coke to be deteriorated after reaction so as to generate a large amount of coke powder; the softening temperature of the ore is reduced, and abnormal expansion of the pellet is caused to lead the pellet to be seriously pulverized; causing furnace wall accretions; after alkali metal steam permeates into the furnace wall, abnormal expansion is generated after oxidation to damage the furnace lining, and the service life of the blast furnace is shortened; others include causing the middle sleeve to upwarp, frequently damaging the sleeve and the like.
To solve the above problems, the following two measures are mainly adopted at present: firstly, controlling the alkali load in the furnace from the source; secondly, the alkali discharge measures are executed to improve the alkali discharge amount of the slag or the zinc discharge amount of the coal gas, and the method comprises the following steps: firstly, reducing the alkalinity R2 of the slag and improving the magnesium-aluminum ratio of the slag; secondly, reducing the furnace temperature for production; and developing central air flow. However, these two measures still have the following drawbacks: (1) if the load of the alkali metal fed into the furnace is strictly controlled, the cost of raw fuel is possibly increased, or solid waste cannot be treated, so that the circular economy is developed; (2) measures for changing slag phase, low furnace temperature production or developing central airflow are often incompatible with blast furnace production requirements, and can cause staged combustion rise; (3) the alkali discharge measures are independently adopted, the alkali metal enriched in the furnace cannot be treated in a centralized manner, the production time is delayed, and the production efficiency is influenced.
Disclosure of Invention
Aiming at the defects in the prior art, the technical problem to be solved by the invention is to provide a process method for the concentrated alkali discharge of a blast furnace, the method can effectively and centrally discharge alkali for the blast furnace by using a planned maintenance opportunity, can reduce the frequency of daily alkali discharge, reduce the adverse effect of daily alkali discharge on the production of the blast furnace, and make up for the defects of daily alkali discharge.
In order to achieve the purpose, the invention discloses a process method for removing alkali in a centralized manner by a blast furnace.
Preferably, the process comprises the following steps:
compiling and determining a periodic blast furnace maintenance plan according to the alkali discharge requirement of the process;
2) when the blast furnace maintenance plan is determined to carry out maintenance according to the step 1), lowering the stockline to the lower part of the furnace body, and then carrying out centralized alkali discharge operation;
3) and processing the slightly thick surface.
Preferably, the method for determining the alkali discharge requirement of the process in the step 1) comprises the following steps:
A. drawing up an alkali load internal control standard suitable for the enterprise;
B. and establishing a balance table of charged harmful element balance according to an alkali load internal control standard, and calculating the alkali discharge rate, so as to determine the time period required for alkali discharge as a scheduled maintenance period.
Preferably, the alkali load internal control standard is Zn less than or equal to 0.4kg/t, K2O≤1.5kg/t，Na2O≤2.5kg/t。
Preferably, in the step B, the harmful element income comprises ore entering the furnace, fuel entering the furnace and flux; the expenditure includes molten iron, slag and dust.
Preferably, the method for determining the alkali discharge requirement of the process in the step 1) further comprises the following steps:
C. focusing on recording the actual appearance occurrence of harmful elements in production;
D. and C, if any index of the bag ash harmful components continuously exceeds a bag ash alkali metal content warning point at a time point before the scheduled maintenance time formulated in the step B is reached, or the discharge rate of any harmful component is reduced by more than 5%, or the actual appearance of harmful elements in production is observed in the step C, alkali discharge is required to be executed, and meanwhile, the period of the maintenance schedule is adjusted to the time interval between the time point and the previous maintenance.
Preferably, the practical appearance of the harmful elements in the step C in production comprises that a short-term damping-down tuyere sleeve is covered with Zn liquid to flow out, alkali metal oxide accumulation exists on the inner wall of a small sleeve or a belly pipe of the short-term damping-down tuyere sleeve, white powder floats out of a backflow damping-down pipe, and white smoke is emitted from a slag iron runner.
Preferably, the cloth bag ash alkali metal content warning points in the step D are respectively as follows: zn: 4.00%, K2O：1.20％，Na2O：0.60％。
Preferably, the concentrated alkali removal operation of step 2) comprises the following steps:
s1, adjusting and increasing the proportion of the acidic material 8 hours before damping down, adding 15-20 kg of serpentine into iron per ton, and controlling the slag alkalinity R2 according to 1.1-1.15 and the ratio of magnesium to aluminum not less than 0.70;
s2, increasing the coke ratio by 20-30 kg/t according to the light load of the furnace temperature condition 8 hours before damping down, and controlling the furnace temperature according to the condition that the furnace temperature is not lower than 0.3%;
s3, adding 3-5 clean coke batches 2-3 hours before blowing down, and controlling the last batch to be coke after blowing down;
s4, controlling the top temperature to be not lower than 200 ℃ 8 hours before damping down, and controlling the top temperature to be 250-300 ℃ after the charge level is lowered so as to ensure that Zn and alkali metal overflow out of the blast furnace along with coal gas;
s5, after damping down, ensuring that the material line reaches not lower than the upper edge of the cooling wall at the lowest layer of the furnace body.
Preferably, the step S4 further includes controlling the top temperature of the material 1 hour before the damping down to 200-250 ℃.
Preferably, the step 3) includes: and (3) treating the thick part of the furnace wall in a water-beating and rapid-cooling mode.
Compared with the prior art, the invention has the advantages and positive effects that: the process method for the concentrated alkali discharge of the blast furnace can effectively perform the concentrated alkali discharge of the blast furnace by using the scheduled maintenance opportunity, can reduce the frequency of daily alkali discharge, reduce the adverse effect of the daily alkali discharge on the production of the blast furnace, and make up for the deficiency of the daily alkali discharge. Specifically, the method comprises the following steps:
(1) the process method of the invention periodically utilizes the opportunity of the blast furnace for fixed maintenance, eliminates the condition of alkali metal steam cycle enrichment in a short time by reducing the stockline to the lower part of the furnace body, and achieves the aims of periodically interrupting the cycle enrichment of harmful elements and intensively discharging the alkali metal enriched in the furnace out of the blast furnace along with the coal gas by utilizing the high-temperature coal gas flow under the condition of low stockline.
(2) The process method of the invention periodically inspects the tidiness of the blast furnace wall, so as to timely process the slight knot thickness of the blast furnace and avoid the influence of gradual expansion of the slight knot thickness on the smooth operation of the blast furnace. The scheduled maintenance opportunity is fully utilized, the accretion condition in the furnace is periodically checked, and the special damping down caused by the treatment of the accretion can be reduced.
Detailed Description
The invention is described in detail below by way of exemplary embodiments. It is to be understood, however, that the structures and features of one embodiment may be beneficially incorporated in other embodiments without further recitation.
A process method for removing alkali from a blast furnace in a centralized manner utilizes periodic maintenance opportunities of the blast furnace to reduce the possibility that a stockline reaches the lower part of a furnace body and then remove alkali. The periodic utilization blast furnace is regularly repaired, the condition of alkali metal steam circulation enrichment is eliminated in a short time by reducing the stockline to the lower part of the furnace body, the purpose of periodically interrupting harmful element circulation enrichment is achieved, the alkali metal enriched in the furnace is intensively discharged out of the blast furnace along with coal gas by utilizing high-temperature coal gas flow under the condition of a low stockline, the alkali metal is intensively discharged at regular intervals by matching with the plan maintenance, the alkali discharging operation is not required to be independently executed for stopping the operation of the blast furnace, the periodic alkali discharging can be realized, the alkali discharging is effectively centralized for the blast furnace, the adverse effect of the daily alkali discharging on the blast furnace production can be reduced, and the deficiency of the daily alkali discharging is made up.
Specifically, the process method comprises the following steps:
1) compiling and determining a periodic blast furnace maintenance plan according to the alkali discharge requirement of the process; before the method, the blast furnace planned maintenance is only formulated according to the running state of equipment, the preparation condition of spare parts and the preparation condition of maintainers, and the blast furnace planned maintenance needs to be compiled by combining the alkali discharge requirement of the process;
2) when the blast furnace maintenance plan is determined to carry out maintenance according to the step 1), lowering the stockline to the lower part of the furnace body so as to intensively cut off the circulating condition that Zn and alkali metal steam are attached to the surface of the cold burden, taking out the Zn and the alkali metal which are circularly enriched out of the furnace through high-temperature coal gas flow in the stockline lowering process, and then carrying out centralized alkali discharge operation;
3) and (3) processing the slight thickness surface, and periodically inspecting the tidiness of the blast furnace wall so as to timely process the slight thickness of the blast furnace and avoid the influence on the smooth operation of the blast furnace caused by gradual expansion of the slight thickness.
Specifically, the method for determining the alkali discharge requirement of the process in the step 1) comprises the following steps:
A. drawing up an alkali load internal control standard suitable for the enterprise;
B. and establishing a balance table of charged harmful element balance according to an alkali load internal control standard, and calculating the alkali discharge rate, thereby determining the time period required for alkali discharge as a planned maintenance period. And (3) establishing a harmful element assay period for each material so as to improve the accuracy and the guidance of the calculated data.
Specifically, for more accurate determination of the maintenance plan, the alkali discharge effect is further ensured, and after the maintenance plan is formulated through the step B, the maintenance cycle of the accurate plan can be adjusted through the following steps:
C. focusing on recording the actual appearance occurrence of harmful elements in production;
D. and C, if any index of harmful components of the bag ash continuously exceeds a bag ash alkali metal content warning point at a time point before the scheduled maintenance time established in the step B is reached, or the discharge rate of any harmful component is reduced by more than 5%, or the actual appearance of harmful elements in production is observed in the step C, alkali discharge is required to be executed, and meanwhile, the period of the maintenance schedule is adjusted to the time interval between the time point and the previous maintenance, so that the scheduled maintenance time is conveniently and fully used.
Specifically, in order to ensure the alkali discharge effect, the internal control standard of the alkali load in the step A is that Zn is less than or equal to 0.4kg/t, K2O is less than or equal to 1.5kg/t, and Na2O is less than or equal to 2.5 kg/t. The alkali load internal control standard can adopt the following industrial standards besides the above standards: zn is less than or equal to 0.15kg/t, K2O+Na2O≤3kg/t。
Specifically, in the step B, the income of harmful elements comprises ore entering the furnace, fuel entering the furnace and flux; the expenditure includes molten iron, slag and dust.
Specifically, the practical appearance of the harmful elements in the step C in production comprises that a short-term damping-down tuyere sleeve is covered with Zn liquid to flow out, alkali metal oxide accumulation exists on the inner wall of a small sleeve or a belly pipe of the short-term damping-down tuyere, white powder floats out of a backflow damping-down pipe, and white smoke is emitted from a slag iron ditch.
Specifically, the cloth bag ash alkali metal content guard points in the step D are respectively: zn: 4.00%, K2O：1.20％，Na2O：0.60％。
Specifically, the concentrated alkali removal operation in the step 2) comprises the following steps:
s1, adjusting and increasing the proportion of the acidic material 8 hours before damping down, adding 15-20 kg of serpentine into iron per ton, and controlling the slag alkalinity R2 according to 1.1-1.15 and the ratio of magnesium to aluminum not less than 0.70;
s2, increasing the coke ratio by 20-30 kg/t according to the light load of the furnace temperature condition 8 hours before damping down, and controlling the furnace temperature according to the condition that the furnace temperature is not less than 0.3%;
s3, adding 3-5 batches of clean coke 2-3 hours before damping down, and controlling the last batch to be coke after damping down;
s4, controlling the top temperature to be not lower than 200 ℃ 8 hours before damping down, and controlling the top temperature to be 250-300 ℃ after the charge level is lowered so as to ensure that Zn and alkali metal overflow out of the blast furnace along with coal gas;
and S5, after damping down, ensuring that the material line is not lower than the upper edge of the cooling wall at the lowest layer of the furnace body.
Specifically, if the maintenance time is short, in order to ensure that the maintenance operation can be normally executed after the damping down, the step S4 further includes controlling the top temperature at 200-250 ℃ 1 hour before the damping down.
Specifically, the step 3) comprises the following steps: and treating the thick part of the furnace wall in a water-beating and quenching way.
Example 1 alkali-removing effect experiment
By the centralized alkali discharge process method, the influence of alkali metal is greatly relieved in a short period after maintenance, and the method has important significance in increasing the yield and reducing the consumption of a blast furnace. Table 1 shows the blast furnace index comparison before and after concentrated alkali removal in 2021 year by the inventor (data comparison adopts two blast furnaces in the same workshop with consistent production conditions, and data of 10 days before and after concentrated alkali removal are taken).
TABLE 1
Through the comparison of the data, the fuel ratio of the blast furnace adopting the concentrated alkali discharge process method of the embodiment is reduced by 5-10kg in a short concentrated alkali discharge period and is compared with the blast furnace without concentrated alkali discharge, and the blast furnace is small (1000 m)3The utilization coefficient of the grade blast furnace) is improved by 0.1 to 0.3 t/(m)3And/d) has great economic benefits.
Although the present invention has been described in detail by way of preferred embodiments, the present invention is not limited thereto. The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims (10)
1. A process method for removing alkali in a blast furnace in a centralized way is characterized in that the alkali is removed after a stockline is lowered to the lower part of a furnace body by utilizing periodic maintenance opportunities of the blast furnace.
2. The blast furnace concentrated alkali discharge process method according to claim 1, comprising the following steps:
1) compiling and determining a periodic blast furnace maintenance plan according to the alkali discharge requirement of the process;
2) when the blast furnace maintenance plan is determined to carry out maintenance according to the step 1), lowering the stockline to the lower part of the furnace body, and then carrying out centralized alkali discharge operation;
3) and processing the slightly thick surface.
3. The blast furnace concentrated alkali discharge process method according to claim 2, wherein the determination method of the process alkali discharge requirement of the step 1) comprises the following steps:
A. drawing up an alkali load internal control standard suitable for the enterprise;
B. and establishing a balance table of charged harmful element balance according to an alkali load internal control standard, and calculating the alkali discharge rate, thereby determining the time period required for alkali discharge as a planned maintenance period.
4. The blast furnace concentrated alkali discharge process method according to claim 3, wherein the alkali load internal control standard is that Zn is less than or equal to 0.4kg/t, K2O≤1.5kg/t，Na2O≤2.5kg/t。
5. The blast furnace concentrated alkali discharging process method according to the claim 3, wherein in the step B, the income of harmful elements comprises ore entering the furnace, fuel entering the furnace and flux; the expenditures include molten iron, slag, and fly ash.
6. The blast furnace concentrated alkali discharge process method according to claim 3, wherein the determination method of the process alkali discharge requirement of the step 1) further comprises the following steps:
C. focusing on recording the actual appearance occurrence of harmful elements in production;
D. and D, if any index of harmful components of the bag ash continuously exceeds a bag ash alkali metal content warning point at a time point before the scheduled maintenance time is reached, or the discharge rate of any harmful component is reduced by more than 5%, or the actual appearance of harmful elements in production is observed in the step C, alkali removal is required, and the period of the maintenance schedule is adjusted to the time interval between the time point and the previous maintenance.
7. The process method for the concentrated alkali discharge of the blast furnace as claimed in claim 6, wherein the practical appearance of harmful elements in the step C in production comprises that a short-term damping-down tuyere sleeve is covered with Zn liquid to flow out, alkali metal oxide accumulation exists on the inner wall of a small short-term damping-down tuyere sleeve or a belly pipe, white powder floats out from a backflow damping-down pipe, and white smoke is emitted from a slag iron runner; the cloth bag ash alkali metal content warning points in the step D are respectively as follows: zn: 4.00%, K2O：1.20％，Na2O：0.60％。
8. The blast furnace concentrated alkali discharge process method according to claim 2, wherein the concentrated alkali discharge operation of the step 2) comprises the following steps:
s1, adjusting and increasing the proportion of the acidic material 8 hours before damping down, adding 15-20 kg of serpentine into iron per ton, and controlling the slag alkalinity R2 according to 1.1-1.15 and the ratio of magnesium to aluminum not less than 0.70;
s2, increasing the coke ratio by 20-30 kg/t according to the light load of the furnace temperature condition 8 hours before damping down, and controlling the furnace temperature according to the condition that the furnace temperature is not less than 0.3%;
s3, adding 3-5 batches of clean coke 2-3 hours before damping down, and controlling the last batch to be coke after damping down;
s4, controlling the top temperature to be not lower than 200 ℃ 8 hours before damping down, and controlling the top temperature to be 250-300 ℃ after the charge level is lowered so as to ensure that Zn and alkali metal overflow out of the blast furnace along with coal gas;
s5, after damping down, ensuring that the material line reaches not lower than the upper edge of the cooling wall at the lowest layer of the furnace body.
9. The blast furnace concentrated alkali discharge process method according to claim 8, wherein the step S4 further comprises controlling the top temperature at 200-250 ℃ 1 hour before the damping down.
10. The blast furnace concentrated alkali discharge process method according to claim 2, wherein the step 3) comprises: and treating the thick part of the furnace wall in a water-beating and quenching way.
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Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| SU1640173A1 (en) * | 1989-04-21 | 1991-04-07 | Череповецкий Металлургический Комбинат Им.50-Летия Ссср | Process for blast furnace operation |
| KR20010058080A (en) * | 1999-12-24 | 2001-07-05 | 이구택 | Operation for discharging alkali to prevent it from sticking on in-furnace |
| CN103436646A (en) * | 2013-09-17 | 2013-12-11 | 武汉钢铁(集团)公司 | Banking method for damping down of large blast furnace |
| CN104152611A (en) * | 2014-08-14 | 2014-11-19 | 北京首钢股份有限公司 | Method for reducing alkali metal enrichment in blast furnace |
| CN108642220A (en) * | 2018-05-25 | 2018-10-12 | 武汉钢铁有限公司 | A method of discharge blast furnace harmful element simultaneously clears up blast furnace design |
| CN112280915A (en) * | 2020-10-09 | 2021-01-29 | 新疆八一钢铁股份有限公司 | Iron-making method by using high-zinc magnetite ore blending |
| CN113025768A (en) * | 2021-02-07 | 2021-06-25 | 首钢集团有限公司 | Blast furnace alkali-discharging method |
-
2022
- 2022-04-27 CN CN202210459045.XA patent/CN114774600A/en active Pending
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| SU1640173A1 (en) * | 1989-04-21 | 1991-04-07 | Череповецкий Металлургический Комбинат Им.50-Летия Ссср | Process for blast furnace operation |
| KR20010058080A (en) * | 1999-12-24 | 2001-07-05 | 이구택 | Operation for discharging alkali to prevent it from sticking on in-furnace |
| CN103436646A (en) * | 2013-09-17 | 2013-12-11 | 武汉钢铁(集团)公司 | Banking method for damping down of large blast furnace |
| CN104152611A (en) * | 2014-08-14 | 2014-11-19 | 北京首钢股份有限公司 | Method for reducing alkali metal enrichment in blast furnace |
| CN108642220A (en) * | 2018-05-25 | 2018-10-12 | 武汉钢铁有限公司 | A method of discharge blast furnace harmful element simultaneously clears up blast furnace design |
| CN112280915A (en) * | 2020-10-09 | 2021-01-29 | 新疆八一钢铁股份有限公司 | Iron-making method by using high-zinc magnetite ore blending |
| CN113025768A (en) * | 2021-02-07 | 2021-06-25 | 首钢集团有限公司 | Blast furnace alkali-discharging method |
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