CN115627312A - Method for desulfurizing molten iron - Google Patents
Method for desulfurizing molten iron Download PDFInfo
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- CN115627312A CN115627312A CN202211135628.3A CN202211135628A CN115627312A CN 115627312 A CN115627312 A CN 115627312A CN 202211135628 A CN202211135628 A CN 202211135628A CN 115627312 A CN115627312 A CN 115627312A
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- slag
- molten iron
- desulfurization
- ladle
- dumping
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- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
- C21C1/00—Refining of pig-iron; Cast iron
- C21C1/02—Dephosphorising or desulfurising
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- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
- C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
- C21C7/0087—Treatment of slags covering the steel bath, e.g. for separating slag from the molten metal
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- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
- C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
- C21C7/04—Removing impurities by adding a treating agent
- C21C7/064—Dephosphorising; Desulfurising
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P10/00—Technologies related to metal processing
- Y02P10/20—Recycling
Abstract
An embodiment of the present application provides a method for desulfurizing molten iron, the method is used for a KR desulfurization treatment line, the method is implemented by a slag adding device, the slag adding device comprises a transportation device and a dumping device, the transportation device and the dumping device are both located in the KR desulfurization treatment line, and the method comprises: conveying the desulfurized slag of the previous ladle of molten iron to the dumping device through the conveying device, wherein the desulfurized slag is residual slag generated after the molten iron is subjected to desulfurization treatment; transporting molten iron to be subjected to a desulfurization reaction to the pouring device; obtaining a first weight of the desulfurization slag of the previous ladle of molten iron at the dumping device, and adding the desulfurization slag of the previous ladle of molten iron into the molten iron to be subjected to desulfurization reaction; and adding an additional desulfurizer into the molten iron to be subjected to the desulfurization reaction, and carrying out the desulfurization reaction. According to the technical scheme, the desulphurization reaction can be carried out on the desulphurization slag of the previous ladle of molten iron in the KR desulphurization treatment line, so that each treatment period in the line can be continuously operated.
Description
Technical Field
The application relates to the technical field of molten iron pretreatment, in particular to a molten iron desulphurization method.
Background
The pretreatment of molten iron is the key to improve the quality of steel, and comprises three items of molten iron desiliconization, desulfurization and dephosphorization. In which, KR method is generally adopted for molten iron desulphurization. However, in actual production, the desulfurization slag generated by molten iron desulfurization can not be recycled in the KR desulfurization treatment line, the operation environment is seriously influenced, and the recycling temperature of the desulfurization slag is reduced.
Based on this, how to realize the desulfurization slag generated by the molten iron desulfurization recycled in the KR desulfurization treatment line is a technical problem to be solved urgently.
Disclosure of Invention
The embodiment of the application provides a molten iron desulphurization method, which can recycle the desulphurization slag of the previous packet of molten iron in a KR desulphurization treatment line for desulphurization reaction, so that each treatment period in the line can be continuously operated.
Other features and advantages of the present application will be apparent from the following detailed description, or may be learned by practice of the application.
According to an aspect of embodiments of the present application, there is provided a method for desulfurizing molten iron, the method being implemented by a slag adding device, the slag adding device including a transporting apparatus and a dumping apparatus, the transporting apparatus and the dumping apparatus both being located in a KR desulfurization processing line, the method including: conveying the desulfurized slag of the previous ladle of molten iron to the dumping device through the conveying device, wherein the desulfurized slag is residual slag generated after the molten iron is subjected to desulfurization treatment; transporting molten iron to be subjected to a desulfurization reaction to the pouring device; obtaining a first weight of the desulfurization slag of the previous ladle of molten iron at the dumping device, and adding the desulfurization slag of the previous ladle of molten iron into the molten iron to be subjected to desulfurization reaction; and adding an additional desulfurizer into the molten iron to be subjected to the desulfurization reaction, and carrying out the desulfurization reaction.
In some embodiments of the present application, based on the foregoing solution, the transportation device includes an intermediate slag bucket, the intermediate slag bucket is used for loading the desulphurization slag, and the transporting the desulphurization slag of the previous ladle of molten iron to the dumping device through the transportation device includes: loading the desulphurization slag of the previous ladle of molten iron by using the intermediate slag hopper; and conveying the intermediate slag hopper loaded with the desulphurization slag of the previous ladle of molten iron to the dumping equipment.
In some embodiments of the present application, based on the foregoing solution, before the intermediate slag hopper loaded with the desulfurized slag of the previous ladle of molten iron is delivered to the dumping apparatus, the method further comprises: and preserving the heat of the desulfurized slag of the previous ladle of molten iron to ensure that the temperature of the desulfurized slag is higher than or equal to 800 ℃.
In some embodiments of the present application, based on the foregoing scheme, the maintaining the temperature of the desulfurized slag of the previous ladle of molten iron to ensure that the temperature of the desulfurized slag is higher than or equal to 800 ℃ includes: and transporting the intermediate slag hopper loaded with the desulfurized slag of the previous ladle of molten iron to the dumping equipment within a first preset time period, and ensuring that the temperature of the desulfurized slag is higher than or equal to 800 ℃.
In some embodiments of the application, based on the foregoing scheme, the dumping apparatus includes a force meter, and the acquiring, at the dumping apparatus, a first weight of the desulphurization slag of the previous ladle of molten iron includes: and acquiring a first weight of the desulphurization slag of the previous ladle of molten iron at the pouring device through the bolthometer.
In some embodiments of the present application, based on the foregoing solution, the pouring device includes a self-locking device, and the adding the desulphurization slag of the previous ladle of molten iron to the molten iron ready for desulphurization reaction includes: when the intermediate slag hopper for loading the desulphurization slag of the previous ladle of molten iron is positioned in the dumping equipment, the self-locking device locks the intermediate slag hopper; the dumping equipment lifts the intermediate slag hopper; and when the intermediate slag hopper rises to a first height, tipping the intermediate slag hopper so that the desulfurized slag of the previous ladle of molten iron is added into the molten iron ready for desulfurization reaction.
In some embodiments of the present application, based on the foregoing, the pouring apparatus comprises a cleaning arrangement, the method further comprising: when the desulfurizing slag of the previous ladle of molten iron is added into the molten iron to be subjected to the desulfurization reaction through the cleaning device, the dust generated in the process of dumping the desulfurizing slag of the previous ladle of molten iron is cleaned.
In some embodiments of the present application, before the additional desulfurizing agent is added to the molten iron to be subjected to a desulfurization reaction, the method further includes: obtaining the residual rate of the desulphurization slag of the previous ladle of molten iron; and determining the mass of the additional desulfurizing agent according to the residual rate and the first weight.
In some embodiments of the present application, based on the foregoing solution, the adding an additional desulfurizing agent to the molten iron to be subjected to a desulfurization reaction to perform the desulfurization reaction includes: and adding an extra desulfurizer into the molten iron to be subjected to the desulfurization reaction, and carrying out the desulfurization reaction for a second preset time.
In some embodiments of the present application, based on the foregoing scheme, the second preset time period is greater than or equal to 8min and less than or equal to 11min.
In the technical scheme provided by some embodiments of the application, the desulfurized slag of the previous ladle of molten iron can be transported to the dumping device through the transportation device, and the desulfurized slag is residual slag generated after the molten iron is subjected to desulfurization treatment; then, the molten iron to be subjected to the desulfurization reaction is transported to the dumping equipment, the first weight of the desulfurization slag of the previous ladle of molten iron is obtained at the dumping equipment, and then the desulfurization slag of the previous ladle of molten iron is added to the molten iron to be subjected to the desulfurization reaction; and finally, adding an extra desulfurizer into the molten iron to be subjected to the desulfurization reaction, and performing the desulfurization reaction. Through the transportation equipment in the KR desulfurization treatment line and empty the equipment, can realize that the desulfurization sediment of one packet of molten iron carries out the desulfurization reaction before the KR desulfurization treatment in-line retrieval and utilization, can also realize empting the process smoke and dust to the desulfurization sediment of one packet of molten iron before and clean removing dust, had not both increased the extra time that is used for transporting the desulfurization sediment, also taken other equipment in the KR desulfurization treatment line, guaranteed each in-line treatment cycle continuous operation.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the application.
Drawings
The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the application and, together with the description, serve to explain the principles of the application. It is obvious that the drawings in the following description are only some embodiments of the application, and that for a person skilled in the art, other drawings can be derived from them without inventive effort. In the drawings:
FIG. 1 illustrates a flow chart of a method of desulfurizing molten iron according to one embodiment of the present application;
FIG. 2 illustrates a detailed flow diagram of the transportation of the desulfurized slag from the previous ladle of molten iron to the dumping apparatus by the transport apparatus according to one embodiment of the present application;
FIG. 3 is a detailed flow chart illustrating the addition of the desulfurized slag of the previous ladle of molten iron to the molten iron ready for the desulfurization reaction according to one embodiment of the present application;
FIG. 4 is a graph showing the relationship between the standing time and the temperature of the desulfurized slag in one embodiment of the present application.
Detailed Description
Example embodiments will now be described more fully with reference to the accompanying drawings. Example embodiments may, however, be embodied in many different forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of example embodiments to those skilled in the art.
Furthermore, the described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided to give a thorough understanding of embodiments of the application. One skilled in the relevant art will recognize, however, that the embodiments of the present application can be practiced without one or more of the specific details, or with other methods, components, devices, steps, and so forth. In other instances, well-known methods, devices, implementations, or operations have not been shown or described in detail to avoid obscuring aspects of the application.
The flow charts shown in the drawings are merely illustrative and do not necessarily include all of the contents and operations/steps, nor do they necessarily have to be performed in the order described. For example, some operations/steps may be decomposed, and some operations/steps may be combined or partially combined, so that the actual execution sequence may be changed according to the actual situation.
It is noted that the terms first, second and the like in the description and claims of the present application and in the drawings described above are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the objects so used are interchangeable under appropriate circumstances such that the embodiments of the application described herein are capable of operation in other sequences than those illustrated or described herein.
It should be noted that the technical scheme of this application is applied to KR method desulfurization process. In the KR method desulfurization process, the one-time utilization rate of the desulfurizer is only 10 percent, wherein the unused part is remained in the desulfurization slag. Therefore, the desulfurization slag has high alkalinity and unsaturated sulfur capacity, can desulfurize molten iron, and has recycling value. Furthermore, the more heat contained in the recycled desulfurization slag, namely the higher the temperature, the better the effect of desulfurization on the molten iron. The cold desulfurization slag is recycled, so that the use quality of a desulfurizing agent can be reduced by 40%; the hot desulfurization slag is recycled, and the use quality of a desulfurizing agent can be reduced by over 50 percent.
The utility model provides a technical scheme both can guarantee the processing cycle normal operating of each ladle in the KR desulfurization treatment line at KR desulfurization treatment inline retrieval and utilization desulfurization sediment, can also remove dust to the desulfurization sediment of retrieval and utilization, reaches cleaner production's purpose, and the desulfurization sediment temperature of retrieval and utilization is higher than or equal to 800 ℃ moreover, is far above the retrieval and utilization temperature of traditional desulfurization sediment 500 ℃.
The implementation details of the technical solution of the embodiment of the present application are set forth in detail below:
fig. 1 illustrates a flowchart of a method of desulfurizing molten iron according to an embodiment of the present application.
Referring to fig. 1, the method for desulfurizing molten iron at least includes steps 110 to 140, which are described in detail as follows:
and 110, conveying the desulfurized slag of the previous ladle of molten iron to the dumping device through the conveying device, wherein the desulfurized slag is residual slag generated after the molten iron is subjected to desulfurization treatment.
In this application, above-mentioned step can be realized through adding the sediment device, it includes the transportation equipment and emptys the equipment to add the sediment device, the transportation equipment with it all is in the KR desulfurization treatment in-line to empty the equipment, the transportation equipment can be including middle sediment fill, slag pot car and sediment fill trailer, middle sediment fill is used for loading the desulfurization sediment, is special do empty the special flourishing sediment equipment of equipment design, the slag pot car with the sediment fill trailer is used for driving middle sediment fill, it can be that the sediment fill promotes tipping device to empty the equipment, be provided with the bracket in the sediment fill promotes tipping device, be used for promoting middle sediment fill.
In an embodiment of step 110 shown in fig. 1, the desulfurized slag of the previous ladle of molten iron is transported to the dumping apparatus by the transportation apparatus, which may be specifically performed according to the steps shown in fig. 2.
Referring to fig. 2, fig. 2 shows a detailed flow chart of the process of transporting the desulfurized slag of the previous ladle of molten iron to the dumping device through the transporting device according to an embodiment of the present application. Specifically, the method comprises steps 111 to 112:
and step 111, loading the desulphurization slag of the previous ladle of molten iron by using the intermediate slag hopper.
And 112, conveying the intermediate slag hopper loaded with the desulfurized slag of the previous ladle of molten iron to the dumping device.
In step 111 of this embodiment, the using of the intermediate slag bucket to load the desulfurized slag of the previous ladle of molten iron may be that after the previous ladle of molten iron enters the KR desulfurization treatment line and is subjected to desulfurization reaction, the desulfurized slag of the previous ladle of molten iron is raked into the intermediate slag bucket by using a slag raking machine, after the slag raking is finished, the intermediate slag bucket loads the desulfurized slag of the previous ladle of molten iron, and at the same time, the previous ladle of molten iron is opened to a ladle position of the KR desulfurization treatment line, and the previous ladle of molten iron is hoisted away from the KR desulfurization treatment line by using a crown block located on the ladle position.
In step 112 of this embodiment, the delivering the intermediate slag ladle loaded with the desulfurized slag from the previous ladle of molten iron to the dumping device may be performed by lowering the bracket of the slag ladle lift-dumping device to a low position, and actuating a slag tanker in the KR desulfurization processing line to deliver the intermediate slag ladle loaded with the desulfurized slag from the previous ladle of molten iron to the slag ladle lift-dumping device.
In this application, before the intermediate slag bucket that will load the desulfurization slag of the previous package of molten iron reaches the dumping equipment, still include: and preserving the heat of the desulfuration residues of the previous ladle of molten iron to ensure that the temperature of the desulfuration residues is higher than or equal to 800 ℃. Specifically, the heat of the desulfurized slag of the previous ladle of molten iron is preserved, and the temperature of the desulfurized slag is ensured to be higher than or equal to 800 ℃, and the temperature of the desulfurized slag can be ensured to be higher than or equal to 800 ℃ by transporting the intermediate slag hopper loaded with the desulfurized slag of the previous ladle of molten iron to the dumping device within a first preset time period.
In an embodiment of the present application, the first preset time period may be 26min, and the dumping device may be a slag bucket lift tipping device. It can be known that the first preset time is negatively related to the temperature of the desulfurized slag of the previous ladle of molten iron. That is, along with the increase of the first preset time, the heat loss of the desulfurization slag of the previous ladle of molten iron is larger, the temperature is lower, and the desulfurization effect is poorer. The first preset time for transporting the middle slag bucket loaded with the desulfurized slag of the previous ladle of molten iron to the slag bucket lifting and tipping device is shortened, so that the heat loss in the desulfurized slag of the previous ladle of molten iron can be reduced, the effect of preserving the heat of the desulfurized slag of the previous ladle of molten iron is achieved, and the temperature of the desulfurized slag of the recycled previous ladle of molten iron is ensured to be higher than or equal to 800 ℃.
It should be noted that other technical means, such as a special heat preservation device, can also be used to preserve the heat of the desulfurized slag in the previous ladle of molten iron, and the range of preserving the heat is not limited to be higher than or equal to 800 ℃.
With continued reference to fig. 1, in step 120, the molten iron ready for the desulfurization reaction is transported to the dumping apparatus.
In this application, after the ladle that prepares to carry out the desulfurization reaction gets into KR desulfurization treatment line, utilize the slagging-off machine to take off the preceding sediment of this package molten iron in the slag ladle of KR desulfurization treatment line. And after slagging off is finished, carrying out temperature measurement sampling on the ladle molten iron to obtain quality parameters of the ladle molten iron so as to determine whether the quality of the ladle molten iron meets the production requirements. The ladle is then transported to a dumping facility, i.e., a slag bucket lift tipping device.
With continued reference to fig. 1, at step 130, a first weight of the desulfurized slag from the previous ladle of molten iron is obtained at the dumping apparatus, and the desulfurized slag from the previous ladle of molten iron is added to the molten iron ready for the desulfurization reaction.
The pouring device comprises a spring chain, and the spring chain is arranged in the slag bucket lifting and tipping device, and the first weight of the desulphurization slag of the previous package of molten iron can be obtained by the spring chain through the spring chain. The dumping equipment further comprises a self-locking device which can be arranged in the slag bucket lifting and dumping device, and the self-locking device can lock the middle slag bucket and a bracket of the slag bucket lifting and dumping device, so that the middle slag bucket can be kept stable in the lifting process, and safety accidents are reduced.
In an embodiment of the step 130 shown in fig. 1, the adding of the desulfurized slag of the previous ladle of molten iron to the molten iron ready for desulfurization may be specifically performed according to the steps shown in fig. 3.
Referring to fig. 3, fig. 3 shows a detailed flowchart of adding the desulfurized slag of the previous ladle of molten iron to the molten iron ready for the desulfurization reaction according to one embodiment of the present application. Specifically, the method comprises steps 131 to 132:
and 131, when the intermediate slag hopper for loading the desulfurized slag of the previous ladle of molten iron is positioned in the dumping equipment, locking the intermediate slag hopper by the self-locking device.
The pouring device raises 132 the intermediate slag hopper.
And 132, when the intermediate slag hopper rises to the first height, tipping the intermediate slag hopper to add the desulfurized slag of the previous ladle of molten iron into the molten iron ready for desulfurization.
In step 131 of this embodiment, when the intermediate slag bucket for loading the desulfurized slag of the previous ladle of molten iron is located in the dumping device, the self-locking device locks the intermediate slag bucket, or when the intermediate slag bucket is located in the bracket of the slag bucket lifting and tipping device, the self-locking device in the bracket of the slag bucket lifting and tipping device is started and locks the intermediate slag bucket.
In step 132 of this embodiment, the dumping apparatus raises the intermediate slag hopper, which may be raised by the slag hopper lift-tipping device via a bracket.
In step 133 of this embodiment, the tipping of the intermediate slag bucket to add the desulfurized slag of the previous molten iron ladle to the molten iron to be subjected to the desulfurization reaction when the intermediate slag bucket is raised to the first height may be performed by tipping the intermediate slag bucket to add the desulfurized slag of the previous molten iron ladle to the molten iron to be subjected to the desulfurization reaction when the intermediate slag bucket is raised to 2/3 of the height of the slag bucket lift tipping device, at which height the intermediate slag bucket can be tipped efficiently and safely to add the desulfurized slag of the previous molten iron ladle to the molten iron to be subjected to the desulfurization reaction.
In this application, topple over the equipment and include clean setting, through cleaning device can be with the doctor slag of preceding package molten iron adds to when preparing to carry out the molten iron of desulfurization reaction, to the doctor slag of preceding package molten iron topples over the process smoke and dust and cleans.
In one embodiment of the application, the upper part of the slag bucket lifting and tipping device can be designed into a closed structure connected with a dust removal system in the KR desulfurization treatment line, so as to collect and remove dust generated in the process of pouring the desulfurized slag. When the desulfuration residues of the previous ladle of molten iron are added into the molten iron to be subjected to desulfuration reaction, the generated smoke dust can be absorbed and treated by a dust removal system of the KR desulfuration treatment line, so that the effect of clean production is achieved.
With continued reference to fig. 1, in step 140, an additional desulfurizing agent is added to the molten iron to be subjected to a desulfurization reaction, and the desulfurization reaction may be performed by: and adding an extra desulfurizer into the molten iron to be subjected to the desulfurization reaction, and carrying out the desulfurization reaction for a second preset time.
In this application, the second preset duration may be greater than or equal to 8min and less than or equal to 11min, the desulfurization reaction may be KR processing, before the extra desulfurizer is added to the molten iron prepared for the desulfurization reaction, before the desulfurization reaction, the method further includes: obtaining the residual rate of the desulphurization slag of the previous ladle of molten iron; and determining the quality of the additional desulfurizer according to the residual rate and the first weight, wherein the residual rate is used for representing the residual amount of the desulfurizer in the desulfurization slag.
Further, a residual rate limit value can be set in the residual rate, and the residual rate limit value is used for representing a residual rate standard for recycling the desulfurized slag. If the residual rate of the desulfurizing agents in a group of desulfurized slags is higher than or equal to the residual rate limit value, the group of desulfurized slags can be recycled. Among them, the limit value of the residual rate is set to be optimal at 90%, because when the residual rate of the desulfurizing agent in the desulfurization slag is 90% (i.e., the desulfurization slag when the desulfurizing agent is used only once), the obtained desulfurization effect is optimal.
In one embodiment of the present application, the residual rate and the first weight of the desulfurized slag of the previous ladle of molten iron, the second weight of the molten iron to be subjected to the desulfurization reaction, and the real-time temperature value may be automatically obtained through a big data pattern table set in the KR desulfurization processing line, and the additional mass of the desulfurizing agent required for determining the molten iron to be subjected to the desulfurization reaction is automatically calculated and added to the molten iron to be subjected to the desulfurization reaction.
In one embodiment of the application, the residual rate of the desulfurized slag of the previous ladle of molten iron can be obtained through a sampling device, the first weight of the desulfurized slag of the previous ladle of molten iron can be obtained through a slag hopper lifting and tipping device, and the available quality of the desulfurizer in the desulfurized slag of the previous ladle of molten iron can be calculated by multiplying the first weight by the residual rate; a quality comparison standard required by the desulfurizer for the molten iron to be subjected to the desulfurization reaction under each condition can be preset, and based on the comparison standard, the corresponding quality required by the desulfurizer for the molten iron to be subjected to the desulfurization reaction can be obtained according to the second weight and the real-time temperature value; the mass difference between the required mass of the desulfurizing agent and the available mass can be calculated and used as the mass of the additional desulfurizing agent required by the molten iron to be subjected to the desulfurization reaction.
In an actual scene of this application, after a packet of molten iron gets into KR desulfurization treatment line and desulfurization, can utilize the slagging-off machine to take off the desulfurization sediment of this packet of molten iron into middle slag hopper. After the slag removal of the desulphurization slag of the ladle molten iron is finished, the slag bucket is lowered to lift the tipping device to a low position, the slag tank truck is started to drive the slag bucket trailer to push the middle slag bucket loaded with the desulphurization slag of the ladle molten iron to the lifting position of the slag bucket lifting tipping device, the locking device is started to lock the slag bucket, and the middle slag bucket is lifted by the slag bucket lifting tipping device to rise to a high position.
When the slag removing of the previous ladle of molten iron is finished, the next ladle of molten iron enters the station, and the slag removing machine can be used for removing the front slag of the second ladle of molten iron into the slag tank. After temperature measurement and sampling, transporting the next ladle of molten iron after pre-slagging to a slag adding position of a slag bucket lifting and tipping device, rotationally tipping the slag bucket lifting and tipping device to add the desulphurization slag of the previous ladle of molten iron loaded in the middle slag bucket into the next ladle of molten iron, and starting a dust removal system all the time in the tipping process.
After the dumping is finished, the slag hopper lifting and tipping device is rotated and reset to be in a horizontal state. And (4) conveying the next packet of molten iron to a desulfurization treatment position, lowering the stirring head, and adding a desulfurizing agent to perform desulfurization reaction. Wherein, the mass of the added additional desulfurizing agent can be 0.
After the desulfurization reaction is finished, the next ladle of molten iron is transported to a converter iron-charging treatment position by using the crane, meanwhile, the slag ladle car is started to drive the slag ladle trailer to be positioned under the slag ladle lifting and tipping device, the slag ladle lifting and tipping device lowers the middle slag ladle and unlocks the locking device to be placed on the slag ladle trailer, and the slag ladle car is started to drive the slag ladle trailer to be positioned at a slag skimming position. By repeating the operation, the aim that the double ladles can be repeatedly applied to the desulfurized slag of the single ladle can be realized.
Use this application technical scheme can directly add preceding package desulfurization sediment to the molten iron of preparing to carry out desulfurization reaction, avoid spiraling outside the KR desulfurization treatment line, can improve the conveying efficiency of preceding package desulfurization sediment reduces will preceding package desulfurization sediment adds to prepare to carry out length of time in the molten iron of desulfurization reaction, can not increase the extra time that is used for transporting the desulfurization sediment in addition, influence online subsequent desulfurization treatment. Specifically, the conventional treatment period of KR desulfurization is 32-37min, and the recycling treatment period of the thermal desulfurization slag using the technical scheme of the application is 33-38min. Meanwhile, dust is removed through a dust removal system in the dumping process of the previous pack of desulfurized slag, and clean production can be realized.
According to the technical scheme, continuous operation of each treatment period in the line can be guaranteed. The process of obtaining and transporting the recycling desulfurization slag is completed in the KR desulfurization treatment line by arranging transportation equipment such as an intermediate slag hopper, a slag tank car, a slag hopper trailer and the like in the KR desulfurization treatment line, on one hand, the extra time for transporting the desulfurization slag is not increased, the subsequent desulfurization treatment in the KR desulfurization treatment line is not hindered, and the treatment period of each ladle in the line can be ensured to continue to operate normally; on the other hand, the process of falling of the inner plate of the factory is avoided, the carrying equipment such as a crown block and the like are not needed to be occupied, other equipment in the KR desulfurization treatment line is not occupied, and the treatment period of the remaining ladles which are not recycled by the desulfurization slag in the line is not influenced. Moreover, the desulfuration residues are prevented from leaving the KR desulfuration processing line, the temperature drop of the furnace slag caused by the fact that the desulfuration residues are coiled in a factory area is avoided, the heat in the desulfuration residues is kept to the maximum extent, the hot desulfuration residues replace part or all of required desulfurizer to carry out desulfuration reaction, the use quality of the desulfurizer in the desulfuration reaction is greatly reduced, the yield of the desulfuration residues after desulfuration processing is reduced, the production cost is reduced, and the environment-friendly purpose of green production is achieved.
And dust removal and cleaning can be performed on the recycled desulphurization slag in the dumping process. Through set up in KR desulfurization treatment line and empty the equipment, for example slag hopper promotes tipping device, associative with the secondary dust pelletizing system in the KR desulfurization treatment line, collect and clean the smoke and dust that the desulfurization sediment of desulfurization emptys the in-process and produce through the regional secondary dust pelletizing system of desulfurization, realize clean production.
In order to make the technical solution provided by the present application better understood by those skilled in the art, the following will briefly explain the technical solution provided by the present application in two practical scenarios.
In a practical scenario of the present application, a comparative test is performed on whether desulfurization slag is recycled in the KR desulfurization treatment line, and the test data is shown in the following table 1:
TABLE 1
The method comprises the following steps of measuring the weight percentage of sulfur element content in molten iron, wherein S% is the measured weight percentage of the sulfur element content in the molten iron, the initial time of entering a KR desulfurization treatment line is the time of entering a station, the end time of leaving the KR desulfurization treatment line is the time of leaving the station (after the desulfurization reaction is finished), the temperature is the measured temperature of the molten iron, the adding amount of a desulfurizing agent is the mass of the desulfurizing agent added into the molten iron to be subjected to the desulfurization reaction, the treatment period is the recorded time length from the time of entering the station to the time of leaving the station, and the temperature of recycled desulfurization slag is the measured temperature of the desulfurization slag of the previous packet of molten iron added into the molten iron to be subjected to the desulfurization reaction.
Further, the temperature drop represents a difference between the molten iron temperature measured at the time of arrival and the molten iron temperature measured at the time of departure. The temperature drop reduction represents a difference between the molten iron temperature measured at the time of arrival and the molten iron temperature measured at the time of departure under the same desulfurization condition (i.e., the actual content of elemental sulfur in the molten iron is the same as the target content of elemental sulfur that is preset to be achieved). The desulfurizing agent reduction ratio means a ratio at which the amount of the desulfurizing agent used is reduced under the same desulfurization condition (i.e., the actual content of sulfur in the molten iron is the same as the target content of sulfur which is preset to be achieved).
From table 1, the proportion of the reduction of the using mass of the desulfurizer in the technical scheme of the application can reach 54% at most, which shows that the using mass of the desulfurizer is greatly reduced in the desulfurization reaction, and further, the generation amount of desulfurization slag after desulfurization treatment is greatly reduced, the generation of environmental pollutants is reduced, and the environmental protection pressure is reduced, thus showing that the technical scheme of the application is progressive.
In another practical scenario of the present application, specifically, after a group of desulfurized slags is recovered, the group of desulfurized slags is left in a factory building, and 6 time points are selected to perform temperature measurement recording on the group of desulfurized slags, and the recorded data is shown in fig. 4.
FIG. 4 is a graph showing the relationship between the standing time and the temperature of the desulfurized slag according to one embodiment of the present invention.
Continuing to refer to fig. 4, the abscissa in fig. 4 is the standing time, and the time unit is min; the ordinate is temperature in degrees Celsius. The 6 solid points in fig. 4 correspond to the actual temperatures of the set of desulfurized slags measured at the selected 6 time points; the dotted line is the predicted temperature decline for the set of desulfurized slags.
It can be known that the standing time is in a negative correlation with the target desulfurizing slag temperature. The larger the heat loss of the set of desulfurized slags is with the increase of the standing time, the lower the temperature is, and the worse the desulfurization effect is.
Based on the relation, the heat loss in the group of the desulfuration residues is reduced by reducing the first preset time for adding the group of the desulfuration residues into the molten iron to be subjected to the desulfuration reaction, so that the heat preservation effect is achieved. As can be seen from fig. 4, if the desulfurized slag is added to the molten iron to be subjected to the desulfurization reaction within 40min, it is possible to ensure that the temperature of the recycled desulfurized slag is greater than or equal to 800 ℃.
Other embodiments of the present application will be apparent to those skilled in the art from consideration of the specification and practice of the embodiments disclosed herein. This application is intended to cover any variations, uses, or adaptations of the invention following, in general, the principles of the application and including such departures from the present disclosure as come within known or customary practice within the art to which the invention pertains.
It will be understood that the present application is not limited to the precise arrangements described above and shown in the drawings and that various modifications and changes may be made without departing from the scope thereof. The scope of the application is limited only by the appended claims.
Claims (10)
1. A method for desulfurizing molten iron, the method being implemented by a slag charging apparatus, the slag charging apparatus comprising a transporting device and a dumping device, the transporting device and the dumping device both being located in a KR desulfurization processing line, the method comprising:
conveying the desulfurized slag of the previous ladle of molten iron to the dumping device through the conveying device, wherein the desulfurized slag is residual slag generated after the molten iron is subjected to desulfurization treatment;
transporting the molten iron to be subjected to desulfurization reaction to the pouring device;
obtaining a first weight of the desulfurization slag of the previous ladle of molten iron at the dumping device, and adding the desulfurization slag of the previous ladle of molten iron into the molten iron to be subjected to desulfurization reaction;
and adding an additional desulfurizer into the molten iron to be subjected to the desulfurization reaction, and carrying out the desulfurization reaction.
2. The method of claim 1, wherein the transportation device comprises an intermediate slag hopper for loading the desulphurization slag, and the transporting the desulphurization slag of the previous ladle of molten iron to the dumping device through the transportation device comprises:
loading the desulphurization slag of the previous ladle of molten iron by using the intermediate slag hopper;
and conveying the intermediate slag hopper loaded with the desulfurized slag of the previous ladle of molten iron to the dumping equipment.
3. The method of claim 2, wherein prior to delivering the intermediate ladle carrying the desulphurised slag of the previous ladle of molten iron to the dumping apparatus, the method further comprises:
and preserving the heat of the desulfurized slag of the previous ladle of molten iron to ensure that the temperature of the desulfurized slag is higher than or equal to 800 ℃.
4. The method according to claim 3, wherein the step of preserving the heat of the desulfurized slag of the previous ladle of molten iron to ensure that the temperature of the desulfurized slag is higher than or equal to 800 ℃ comprises the following steps:
and transporting the intermediate slag hopper loaded with the desulfurized slag of the previous ladle of molten iron to the dumping equipment within a first preset time period, and ensuring that the temperature of the desulfurized slag is higher than or equal to 800 ℃.
5. The method of claim 1, wherein the dumping apparatus includes a bolerometer, and the obtaining a first weight of the desulfurized slag of the previous ladle of molten iron at the dumping apparatus includes:
obtaining a first weight of the desulphurization slag of the previous ladle of molten iron through the bolthometer at the pouring device.
6. The method of claim 1, wherein the dumping apparatus comprises a self-locking arrangement, and wherein the adding of the desulfurized slag from the previous ladle of molten iron to the molten iron ready for the desulfurization reaction comprises:
when the intermediate slag hopper for loading the desulphurization slag of the previous ladle of molten iron is positioned in the dumping equipment, the self-locking device locks the intermediate slag hopper;
the dumping equipment lifts the intermediate slag hopper;
and when the intermediate slag hopper rises to a first height, tipping the intermediate slag hopper so that the desulfurized slag of the previous ladle of molten iron is added into the molten iron ready for desulfurization reaction.
7. The method of claim 1, wherein the pouring apparatus comprises a cleaning arrangement, the method further comprising:
when the desulfurizing slag of the previous ladle of molten iron is added into the molten iron to be subjected to the desulfurization reaction through the cleaning device, the dust generated in the process of dumping the desulfurizing slag of the previous ladle of molten iron is cleaned.
8. The method according to claim 1, wherein before the additional desulfurizing agent is added to the molten iron to be subjected to the desulfurization reaction, the method further comprises:
obtaining the residual rate of the desulphurization slag of the previous ladle of molten iron;
and determining the mass of the additional desulfurizing agent according to the residual rate and the first weight.
9. The method of claim 1, wherein the step of adding an additional desulfurizing agent to the molten iron to be subjected to the desulfurization reaction to perform the desulfurization reaction comprises:
and adding an extra desulfurizer into the molten iron to be subjected to the desulfurization reaction, and carrying out the desulfurization reaction for a second preset time.
10. The method according to claim 9, wherein the second preset time period is greater than or equal to 8min and less than or equal to 11min.
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| JP2007262465A (en) * | 2006-03-28 | 2007-10-11 | Jfe Steel Kk | Method for desulfurizing molten pig iron |
| JP2007332403A (en) * | 2006-06-13 | 2007-12-27 | Jfe Steel Kk | Method for desulfurizing molten iron |
| CN106702070A (en) * | 2016-12-13 | 2017-05-24 | 北京首钢国际工程技术有限公司 | KR desulfuration slag thermal state recycling method |
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| CN113373275A (en) * | 2021-05-07 | 2021-09-10 | 武汉科技大学 | Internal recycling method for KR desulfurization slag steel plant |
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|---|---|---|---|---|
| JP2007262465A (en) * | 2006-03-28 | 2007-10-11 | Jfe Steel Kk | Method for desulfurizing molten pig iron |
| JP2007332403A (en) * | 2006-06-13 | 2007-12-27 | Jfe Steel Kk | Method for desulfurizing molten iron |
| CN106702088A (en) * | 2016-11-22 | 2017-05-24 | 首钢京唐钢铁联合有限责任公司 | Method for increasing utilization rate of desulfurization agent in KR desulfurization process |
| CN106702070A (en) * | 2016-12-13 | 2017-05-24 | 北京首钢国际工程技术有限公司 | KR desulfuration slag thermal state recycling method |
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