A method of monitoring the use of a slag notch in an ironmaking process

Abstract

The application discloses an iron smelting method for monitoring slag channel use, and belongs to the technical field of blast furnace iron smelting in the steel industry. The method is specifically operated as follows: planning monitoring points; developing overall pouring, vibrating and standardized maintenance of slag channel refractory materials; after the refractory material is completely solidified and reaches the standard, cleaning the sleeve pipeline, inserting corresponding specification thermocouples into the sleeve one by one, connecting an external temperature collection and intelligent early warning monitoring system, completing line debugging and parameter calibration, and blocking the sleeve with refractory material after confirming that the signal transmission is correct; starting real-time online monitoring when the blast furnace is normally slagging; after the system triggers an audible and light early warning, reminding the operator to timely carry out slag channel repair work. The application realizes accurate quantitative judgment of the erosion depth of the overall slag channel refractory material by standardizing the pre-buried monitoring components in the pouring process of the slag channel, realizes real-time grasping of the use state of the slag channel, maximizes the use of the strength of the slag channel refractory material while ensuring the safety of production, and avoids excessive repair and resource waste.

Description

Technical Field

[0001] This invention belongs to the field of blast furnace ironmaking technology in the iron and steel industry, and particularly relates to an ironmaking method for monitoring the use of slag troughs. Background Technology

[0002] Blast furnaces are the core equipment in modern steelmaking. Slag removal operations in front of the furnace are a key link to ensure the stable operation of the blast furnace. As the core structure for conveying and discharging high-temperature molten slag, the slag ditch directly affects the safety, continuity and economy of blast furnace production.

[0003] The slag discharge trough operates under extreme conditions: it is continuously subjected to the scouring and chemical erosion of molten slag at temperatures above 1400℃. Furthermore, the intermittent slag discharge causes severe temperature fluctuations, resulting in thermal stress that leads to refractory material cracking and spalling. Slag penetration further accelerates structural damage. With the increasing size of blast furnaces and the improvement in smelting intensity, the slag discharge volume, flow rate, and duration are continuously increasing, exacerbating the erosion of the slag discharge trough lining and becoming a challenge for furnace safety and cost control.

[0004] Currently, the industry generally relies on manual experience to judge the erosion status of slag trenches, which has prominent drawbacks: First, it has poor accuracy and strong subjectivity, making it impossible to quantify the erosion depth and easily leading to misjudgments and omissions; second, it poses high safety risks, with close-range detection facing the dangers of high-temperature burns and slag splashing, and the lack of real-time early warning can easily lead to slag leakage, equipment damage, or even blast furnace shutdown accidents; third, it results in serious cost waste, with the "advance maintenance" strategy leading to excessive consumption of refractory materials and low utilization rate; fourth, it cannot adapt to the needs of refined production, lacks real-time data support, and restricts the intelligent management of furnace front operations.

[0005] Currently, the industry lacks mature online precision monitoring technology, and existing methods are insufficient to meet the demands of efficient, safe, and low-cost production. Therefore, developing a reliable and safe method for detecting the lifespan of slag discharge channels—one that can accurately quantify erosion depth, monitor service life in real time, and achieve scientific management of slag discharge channel lifespan—is an urgent need for optimizing furnace-front processes. This method is of great significance for improving production safety, reducing costs, and promoting technological upgrades. Summary of the Invention

[0006] To address the problems of insufficient accuracy, high safety risks, and serious resource waste in current blast furnace slag discharge trough life detection technologies, this invention proposes a blast furnace slag discharge trough life detection method based on thermocouple pre-embedded monitoring. By standardizing the pre-embedded monitoring components during the slag discharge trough pouring process, the method can accurately quantify the erosion depth of the overall slag discharge trough refractory material, monitor the slag discharge trough usage status in real time, maximize the utilization of slag discharge refractory material strength while ensuring production safety, and avoid excessive maintenance and resource waste.

[0007] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0008] This invention discloses an ironmaking method for monitoring the usage of slag ditches, the specific operation of which is as follows:

[0009] The monitoring points are planned and evenly distributed along the longitudinal and transverse directions of the slag discharge ditch at intervals of 0.4-0.6 meters to fully cover the key areas of slag discharge ditch scouring and erosion. Each monitoring point is equipped with three sets of monitoring positions at different depths. Before the refractory material is poured in the slag discharge ditch, hollow pipe sleeves with an inner diameter of 1.4-1.6 cm are pre-embedded at depths corresponding to 60%, 40%, and 20% of the total refractory material thickness, and fixed with brackets to prevent displacement and blockage during pouring.

[0010] The refractory material in the slag discharge ditch is poured, vibrated, and cured in a standardized manner. After the refractory material has completely solidified and met the standard, the sleeve pipeline is cleaned, and thermocouples of the corresponding specifications are inserted into the sleeve one by one. The external temperature acquisition and intelligent early warning monitoring system is connected, and the circuit debugging and parameter calibration are completed to ensure stable signal transmission. After confirming that the signal transmission is correct, the sleeve is sealed with refractory material.

[0011] During normal slag removal operations in the blast furnace, real-time online monitoring is activated. The high-temperature molten slag gradually erodes the refractory material in the slag trench. As the refractory material peels off, thermocouples at different depths come into contact with the high-temperature molten slag and burn out, resulting in signal interruption. The monitoring system accurately determines the erosion depth of the refractory material based on the order in which the thermocouple signals disconnect: the first layer of thermocouple signal interruption indicates erosion of 40%; the second layer of interruption indicates erosion of 60%; and the third layer of interruption indicates erosion of 80%, reaching the safety threshold.

[0012] The system immediately triggered an audible and visual warning, reminding operators to promptly carry out slag ditch repair work.

[0013] Furthermore, monitoring points were evenly distributed along the longitudinal and transverse directions of the slag discharge ditch at intervals of 0.5 meters.

[0014] Furthermore, the inner diameter of the hollow tube sleeve is 1.5 cm.

[0015] Furthermore, during maintenance, only the damaged thermocouple needs to be replaced, and the refractory material can be repaired before monitoring can be restarted and reused.

[0016] Furthermore, monitoring points were evenly distributed along the longitudinal and transverse directions of the slag discharge ditch at intervals of 0.4 meters.

[0017] Furthermore, monitoring points were evenly distributed along the longitudinal and transverse directions of the slag discharge ditch at intervals of 0.6 meters.

[0018] Furthermore, this method does not require any changes to the original production process or on-site close-range manual inspection, enabling all-weather automated and precise monitoring.

[0019] Compared with the prior art, the beneficial technical effects of the present invention are as follows:

[0020] The method of this invention does not require modification of the original production process, does not require manual on-site close inspection, realizes all-weather automated and accurate monitoring, is convenient to operate and maintain, can effectively avoid safety risks, maximize the utilization of refractory materials, and is suitable for life monitoring of slag discharge channels of various blast furnaces. Detailed Implementation

[0021] The specific implementation steps of this invention are simple and seamlessly integrated with the slag discharge ditch construction, production, and maintenance processes. The specific operation is as follows:

[0022] First, monitoring points were planned and evenly distributed along the longitudinal and transverse directions of the slag discharge ditch at 0.5-meter intervals to fully cover the key areas affected by scouring and erosion. Each monitoring point was equipped with three sets of monitoring positions at different depths. Before the refractory material was poured into the slag discharge ditch, hollow pipe sleeves with an inner diameter of 1.5 cm were pre-embedded at depths corresponding to 60%, 40%, and 20% of the total refractory thickness, and fixed with supports to prevent displacement and blockage during pouring.

[0023] Secondly, the refractory material in the slag discharge ditch is poured, vibrated, and cured in a standardized manner. After the refractory material has completely solidified and met the standards, the sleeve pipeline is cleaned, and thermocouples of the corresponding specifications are inserted into the sleeve one by one. The external temperature acquisition and intelligent early warning monitoring system is connected, and the line debugging and parameter calibration are completed to ensure stable signal transmission. After confirming that the signal transmission is correct, the sleeve is sealed with refractory material.

[0024] During normal blast furnace slag removal operations, real-time online monitoring is activated. High-temperature molten slag gradually erodes the refractory material in the slag trench. As the refractory material peels away, thermocouples at different depths sequentially come into contact with the high-temperature molten slag and burn out, eventually losing their signal. The monitoring system accurately determines the erosion depth of the refractory material based on the sequence of thermocouple signal disconnection: the first layer of thermocouple signal disconnection indicates 40% erosion; the second layer indicates 60% erosion; and the third layer indicates 80% erosion, reaching the safety threshold.

[0025] The system immediately triggers an audible and visual alarm, reminding operators to promptly carry out slag trench repair work. During maintenance, only the damaged thermocouple needs to be replaced, and the refractory material repaired before monitoring can be restarted for repeated use.

[0026] This implementation method requires no modification to the original production process and no manual on-site close inspection. It achieves all-weather automated and accurate monitoring, is easy to operate and maintain, can effectively avoid safety risks, maximize the use of refractory materials, and is suitable for life monitoring of slag discharge channels in various blast furnaces.

[0027] The technical solution of the present invention will be described in detail below with reference to the embodiments.

[0028] Example 1

[0029] The remaining thickness of the slag trough in a 2000m³ blast furnace was previously estimated by the furnace operators through methods such as probing with iron pipes and visual observation. Later, the technology of this invention was used to modify the 2000m³ blast furnace slag trough, which made the measurement of the remaining thickness of the slag trough more accurate and the modification effect was good.

[0030] Example 2

[0031] A 3000m³ blast furnace slag trough was damaged due to inadequate maintenance, causing slag to fall and burn the blast furnace equipment, forcing the blast furnace to shut down. After the technology of this invention was used to modify the 3000m³ blast furnace slag trough, effective management of the residual thickness and maintenance of the slag trough was established, and no slag trough rupture has occurred since then.

[0032] Example 3

[0033] Due to the quality of the refractory material in the slag trough, a sudden leakage occurred in the slag trough during the warranty period, forcing the blast furnace to shut down. After the 4000m3 blast furnace slag trough was modified using the technology of this invention, the furnace operators had a clearer understanding of the slag trough's operating status, effectively preventing damage to the slag trough.

[0034] The core technical principle of this invention is to accurately correspond the erosion depth of the refractory material in the slag discharge ditch by utilizing the temperature monitoring and burn-off status feedback of thermocouples. During the refractory material casting construction stage of the slag discharge ditch, a customized hollow tube sleeve is pre-embedded. The sleeve diameter is set at 1.5 cm, which is slightly larger than the diameter of a conventional thermocouple. This ensures that the thermocouple can be smoothly inserted, making installation and replacement convenient, while preventing the overall structural strength of the refractory material in the slag discharge ditch from being damaged due to the excessively large sleeve size. This ensures that the structure of the slag discharge ditch is stable after casting and does not affect normal slag discharge operations.

[0035] Regarding the layout of monitoring points, a standardized and comprehensive deployment principle is followed. Temperature monitoring points are evenly distributed with a spacing of 0.5 meters horizontally and vertically to ensure comprehensive monitoring of all areas of the slag trench, eliminating blind spots and fully covering critical areas prone to erosion and high scour. Each set of temperature monitoring points is equipped with three thermocouples, which are inserted into the refractory material of the slag trench. The insertion depth is precisely controlled according to 60%, 40%, and 20% of the total depth of the refractory material, forming a hierarchical depth monitoring system. This allows for precise classification and real-time monitoring of different erosion levels. After the thermocouples are inserted into the sleeve, the sleeve is grouted and sealed.

[0036] In actual production operations, high-temperature molten slag continuously erodes the refractory material in the slag trench, and the thickness of the refractory material gradually decreases with erosion. When the erosion depth of the refractory material in the slag trench reaches 40%, the first layer of thermocouples inserted at this depth will be burned off due to the refractory material peeling off and direct contact with the high-temperature molten slag. The monitoring system will not receive the temperature signal from this thermocouple, thus accurately determining that the erosion depth of the slag trench has reached 40%. As the erosion intensifies further, when the erosion depth reaches 60%, the second layer of thermocouples at the corresponding depth will burn off, thus determining that the erosion depth of the slag trench has reached 60%. When the erosion depth reaches 80%, the third layer of thermocouples will burn off, indicating that only 20% of the refractory material remains in the slag trench. Through the feedback of the layered burning off of the three layers of thermocouples, the erosion process of the refractory material in the slag trench can be monitored in real time and accurately. When the erosion depth of the slag trench reaches 80% and the remaining refractory material only meets the basic safety requirements, slag trench maintenance work will be initiated immediately to eliminate safety hazards in a timely manner.

[0037] This invention is simple and easy to implement. The pre-embedding of the empty pipe sleeve and the pouring of the slag trench are carried out simultaneously, requiring no significant modifications to the existing slag trench construction process. It does not increase construction difficulty or time. Thermocouple installation and replacement are convenient, the monitoring system is reusable, and maintenance costs are low. This method completely eliminates the drawbacks of traditional manual experience-based judgment, achieving accurate quantification, real-time online, and objective monitoring of the slag trench erosion degree. It solves the core problems of poor accuracy and high safety risks associated with traditional detection methods, providing furnace-front workers with accurate slag trench life data and enabling the scientific development of maintenance plans.

[0038] Meanwhile, this invention effectively balances production safety and resource utilization. It provides timely warnings when the slag channel reaches a critical erosion state, preventing slag leakage, equipment damage, and other safety accidents, ensuring continuous and stable blast furnace operation. It also avoids refractory waste caused by conservative maintenance, fully utilizing the remaining strength of the slag channel refractory material, significantly reducing refractory material consumption and maintenance frequency, and lowering blast furnace production costs. Furthermore, this detection method is highly stable and provides reliable monitoring data. It is adaptable to blast furnace slag channels of different volumes and smelting conditions, making it easy to promote and apply in the steel industry. This effectively improves the precision and intelligent management of blast furnace operations, promotes the optimization and upgrading of blast furnace front-end technology, and possesses significant safety, economic, and technological promotion value.

[0039] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A method for monitoring the use of slag ditches in ironmaking, characterized in that, The specific steps are as follows: The monitoring points are planned and evenly distributed along the longitudinal and transverse directions of the slag discharge ditch at intervals of 0.4-0.6 meters to fully cover the key areas of slag discharge ditch scouring and erosion. Each monitoring point is equipped with three sets of monitoring positions at different depths. Before the refractory material is poured in the slag discharge ditch, hollow pipe sleeves with an inner diameter of 1.4-1.6 cm are pre-embedded at depths corresponding to 60%, 40%, and 20% of the total refractory material thickness, and fixed with brackets to prevent displacement and blockage during pouring. The refractory material in the slag discharge ditch is poured, vibrated, and cured in a standardized manner. After the refractory material has completely solidified and met the standard, the sleeve pipeline is cleaned, and thermocouples of the corresponding specifications are inserted into the sleeve one by one. The external temperature acquisition and intelligent early warning monitoring system is connected, and the circuit debugging and parameter calibration are completed to ensure stable signal transmission. After confirming that the signal transmission is correct, the sleeve is sealed with refractory material. During normal blast furnace slag removal operations, real-time online monitoring is activated. High-temperature molten slag gradually erodes the refractory material in the slag trench. As the refractory material peels off, thermocouples at different depths sequentially come into contact with the high-temperature molten slag and burn out, resulting in signal interruption. The monitoring system accurately determines the erosion depth of the refractory material based on the order in which the thermocouple signals disconnect: the interruption of the first layer of thermocouple signals indicates that the erosion has reached 40%. The second layer of interruption indicates that the erosion has reached 60%; the third layer of interruption indicates that the refractory material has eroded to 80%, reaching the safety threshold. The system immediately triggered an audible and visual warning, reminding operators to promptly carry out slag ditch repair work.

2. The ironmaking method for monitoring the use of slag ditches according to claim 1, characterized in that, Monitoring points were evenly distributed along the longitudinal and transverse directions of the slag discharge ditch at intervals of 0.5 meters.

3. The ironmaking method for monitoring the use of slag ditches according to claim 1, characterized in that, The inner diameter of the hollow tube sleeve is 1.5 cm.

4. The ironmaking method for monitoring the use of slag ditches according to claim 1, characterized in that, During maintenance, only the damaged thermocouple needs to be replaced and the refractory material repaired before monitoring can be restarted and reused.

5. The ironmaking method for monitoring the use of slag ditches according to claim 1, characterized in that, Monitoring points were evenly distributed along the longitudinal and transverse directions of the slag discharge ditch at intervals of 0.4 meters.

6. The ironmaking method for monitoring the use of slag ditches according to claim 1, characterized in that, Monitoring points were evenly distributed along the longitudinal and transverse directions of the slag discharge ditch at intervals of 0.6 meters.

7. The ironmaking method for monitoring the use of slag ditches according to claim 1, characterized in that, This method requires no changes to the original production process and no manual on-site close-range inspection, achieving all-weather automated and accurate monitoring.