A method of increasing campaign life

Abstract

The application discloses a method for prolonging the service life of a furnace, and the method comprises the following steps: step 1) adding molten iron, scrap steel and slag into the furnace body, and then performing steelmaking, wherein the steelmaking temperature is 1630-1650 DEG C; step 2) after the completion of one pouring cycle of continuous casting, replacing the tundish for 2-3 hours, and maintaining the weak part of the lining of the converter; the continuous casting pouring cycle is shortened by 2-3 minutes, and the ladle temperature is increased by 5-10 DEG C; step 3) increasing the pulling speed of the continuous casting machine, and lowering the temperature required by the continuous casting machine for the converter, and controlling the superheat of the molten steel in the tundish to be within 10-20 DEG C; step 4) after the completion of the steelmaking of the furnace body, controlling the carbon content at the end point of the converter; after the completion of the sampling and temperature measurement of the converter, directly performing steel tapping without waiting for the end point component result; step 5) using a thickness measuring instrument to measure the thickness of the lining every week, and mastering the change of the lining. Through the carbon preservation and steel tapping, the continuous casting optimization process, the reduction of the pouring temperature and the reduction of the tapping temperature of the converter, the erosion of the lining is reduced; the scrap steel ratio is increased, and the consumption of the molten iron (ore, coke and the like) is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of steelmaking, in particular to a method for improving furnace life. BACKGROUND

[0002] Steelmaking refers to controlling the carbon content (generally less than 2%), eliminating harmful elements such as P, S, O, N, retaining or increasing beneficial elements such as Si, Mn, Ni, Cr, and adjusting the ratio between elements to obtain the best performance. Put the pig iron for steelmaking into the steelmaking furnace and melt according to a certain process, and then steel is obtained. The products of steel include steel ingots, continuous casting billets, and various steel castings directly cast, etc. Generally, the steel refers to the steel rolled into various steel materials. Steel belongs to ferrous metal, but steel is not equal to ferrous metal.

[0003] In the steelmaking process, a converter needs to be used. The long-term work of the converter will erode the converter lining, affecting its service life, thereby increasing the production cost. Therefore, a method for improving furnace life is needed. SUMMARY

[0004] The purpose of the present application is to provide a method for improving furnace life, which reduces the erosion of the lining by preserving carbon during tapping, not equalizing the tapping, optimizing the continuous casting process, reducing the pouring temperature, reducing the tapping temperature of the converter, increasing the scrap ratio, and reducing the consumption of molten iron (ore, coke, etc.).

[0005] To solve the above technical problems, the present application adopts the following technical scheme:

[0006] A method for improving furnace life, the method comprising the following steps:

[0007] Step 1) After adding molten iron, scrap steel and slag into the converter, steelmaking is carried out, and the steelmaking temperature is 1630-1650℃;

[0008] Step 2) After one pouring cycle of continuous casting is completed, the continuous casting is replaced for 2-3 hours, and the converter lining is maintained at the weak position; the continuous casting pouring cycle is shortened by 2-3 minutes, and the ladle temperature is increased by 5-10℃;

[0009] Step 3) The continuous casting machine increases the pulling speed, and the continuous casting requires the temperature of the converter to be reduced, and the superheat degree of the molten steel in the tundish is controlled within 10-20℃;

[0010] Step 4) The carbon content at the end point of the converter is controlled during the steelmaking process of the converter; after the sampling and temperature measurement of the converter are completed, the steel is directly tapped without waiting for the end point composition results.

[0011] Step 5) A thickness measuring instrument is used to measure the thickness of the lining every week to master the change of the lining.

[0012] Further, in step 1), the configuration mass ratio of molten iron, scrap steel and slag is 75-80:15-18:2-10.

[0013] Further: in the step 2), the brick supplement, the deduction supplement and the casting supplement are carried out by using the casting time.

[0014] Further: in the step 3), the temperature of the continuous casting is required to be reduced to 1550℃.

[0015] Further: in the step 3), the oxygen content of the molten steel is increased by 80-100ppm.

[0016] Further: in the step 4), the carbon content at the end point is greater than 0.08%.

[0017] Further: in the step 4), the temperature for measuring is 1630-1650℃.

[0018] Further: in the step 4), the components for the unequal sample detection are carbon, manganese, phosphorus and sulfur.

[0019] Compared with the prior art, the present application has at least one of the following beneficial effects:

[0020] (1) By unequal sample tapping, the furnace soaking time is reduced, and the smelting cycle is shortened. Unequal sample tapping, tapping temperature control, using the casting time to supplement the brick, the deduction supplement and the casting supplement, using the thickness gauge to monitor the converter lining; the continuous casting optimizes the casting temperature, which is reduced from 1560℃ to 1550℃, the casting cycle is shortened, the ladle turnover is fast, and the ladle temperature is reduced. The continuous casting optimization process reduces the casting temperature, reduces the tapping temperature of the converter, reduces the erosion of the lining; increases the scrap ratio, reduces the consumption of molten iron (ore, coke, etc.). Improve the furnace life to meet production.

[0021] (2) The iron-making blast furnace does not slow down or stop due to the converter condition; the continuous casting does not stop due to the converter condition; energy saving and consumption reduction. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 It is the first erosion diagram of the prior art lining.

[0023] Figure 2 It is the second erosion diagram of the prior art lining.

[0024] Figure 3 It is the third erosion diagram of the prior art lining. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical scheme and advantages of the present application clearer, the present application will be further described in detail below in combination with the drawings and examples. It should be understood that the specific examples described herein are only used to explain the present application and do not limit the present application.

[0026] Example 1:

[0027] Converter in the addition of molten iron, scrap, slag for steelmaking, temperature is too high (≥1655 ℃) corresponding molten steel oxygen content increases, temperature is too low (≤1625 ℃) can not be tapped.

[0028] After the continuous casting a pouring end, continuous casting needs to change the tundish, converter maintenance lining weak. Continuous casting casting cycle is shortened, continuous casting optimization process, empty package hot running time is short, ladle heat loss is less.

[0029] Use the time to change the pouring to brick, deduction, investment; brick repair: using tools to send the converter brick to the lining weak place for maintenance; deduction repair: is to put the repair material into the scrap steel bucket, using the crane to pour the repair material into the converter, for the maintenance of the lining; investment repair: the foreman hand repair material (also known as hand feeding) into the converter for the maintenance of the lining, the above measures are to improve the service life of the converter lining.

[0030] Continuous casting machine to improve the speed, from the original casting cycle 31 min to 28 min / furnace, continuous casting temperature requirements from 1560 ℃ to 1550 ℃, strict control of the tundish molten steel superheat. Ladle turnover is fast, reduce the ladle heat loss, converter tapping temperature is reduced by about 10 ℃; due to the low tapping temperature, low oxygen content of molten steel, less erosion of the lining, improve the service life of the converter lining. After blowing, the oxygen content of molten steel increases, the residual manganese of molten steel increases by 0.03-0.05%, the silicon manganese alloy per ton of steel is reduced by 0.43-0.71 kg, the oxygen content of molten steel is low, the FeO in the slag is less than or equal to 12%, and the molten steel has less erosion on the lining.

[0031] The converter smelting process controls the carbon content of the converter endpoint; after the converter sampling and temperature measurement are completed, the tapping is directly carried out without waiting for the endpoint composition results of the analysis, the main detection components are carbon, manganese, phosphorus and sulfur, and the tapping temperature is 1635 ℃. The analysis results take 2 minutes and 30 seconds, and the direct tapping can save 1 minute and 30 seconds, reduce the soaking time of molten steel in the lining, reduce the consumption of the lining, and improve the operation rate of the converter, that is, the tapping without sample.

[0032] The carbon content of the converter endpoint is greater than 0.08%, due to the high carbon content, the purity of the molten steel is high, the oxygen content is low, the residual manganese content is high, the deoxidizing material and alloy consumption are saved, the oxygen content is low, the erosion on the converter lining is small, the service life of the converter lining is improved, and the consumption of the repair material is reduced, that is, the tapping with carbon. The terminal manganese content increases by 0.057% when the terminal carbon is greater than and less than 0.08%, which is equivalent to reducing 120 kg of silicon manganese alloy per furnace, and reducing 0.86 kg per ton of steel. During the furnace campaign, 21150 furnaces were produced, and according to the amount of qualified billet of 139 t, a total of 293.9850 million tons were produced, and 3418.43 tons of silicon manganese alloy were saved.

[0033] The thickness of the furnace lining is measured every week using a thickness measuring instrument to understand the change of the furnace lining, so that the deterioration of the furnace can be found in time, and the service life of the converter furnace lining can be improved through operation and maintenance, and the leakage accident can be prevented. Through the regular measurement of the converter furnace lining by the thickness measuring instrument, the weak area is maintained by brick repair, and the consumption of the repair material per ton of steel is reduced by 0.05 kg.

[0034] Other embodiments are operated according to the preparation method in Example 1. The application is further described in detail in combination with the following examples, as shown in Table 1.

[0035] Table 1 Process parameter table of the embodiment of the application

[0036]

[0037] Through the steelmaking by the example, the qualified steel billets of 2939850 tons are produced in the whole furnace campaign, 147 tons of repair material are saved, 3163*147=464961 yuan. The silicon-manganese alloy of ton of steel is reduced by 0.43-0.71 kg, 0.51*2939850*5811 / 1000=7687561 yuan.

[0038] The temperature of each furnace of steel is reduced by 5-10℃, 1℃=0.6 yuan, 21150*0.6*7=88830 yuan.

[0039] Total: 464961+7687561+88830=824.1352 million yuan.

[0040] Although the application has been described with reference to the explanatory embodiments thereof, it should be understood that many other modifications and implementations would be apparent to those skilled in the art, which would be within the scope and spirit of the principles disclosed herein. More specifically, many variations and modifications would have been suggested to those skilled in the art from a consideration of the disclosure of the application, the drawings and the claims. It is therefore intended that all such variations and modifications be included within the scope of the application.

Claims

1. A method for increasing furnace life, characterized in that: The method includes the following steps: Step 1) After adding molten iron, scrap steel, and slag to the furnace, steelmaking is carried out at a temperature of 1630-1650℃. Step 2) After one continuous casting cycle is completed, the tundish is replaced for 2-3 hours, and the weak points of the converter lining are maintained; the continuous casting cycle is shortened by 2-3 minutes, and the ladle temperature is reduced by 5-10℃; Step 3) Increase the casting speed of the continuous casting machine. The continuous casting requires a decrease in the converter temperature. Control the superheat of the molten steel in the tundish to within 10-20℃. Step 4) After the steelmaking process in the furnace is completed, control the carbon content at the converter endpoint; after the converter is turned over for sampling and temperature measurement, tap the steel directly without waiting for the results of the endpoint composition analysis. Step 5) Use a thickness gauge to measure the furnace lining thickness weekly to monitor changes in the furnace lining. In step 1), the mass ratio of molten iron, scrap steel, and slag is 75-80:15-18:2-10. In step 2), brick patching, clipping, and filling are carried out during the time of the replacement pouring; In step 3), the continuous casting converter requires the temperature to be reduced to 1555℃; In step 3), the oxygen content of the molten steel increases by 80-100 ppm; In step 4), the carbon content at the endpoint is greater than 0.08%; In step 4), the temperature measured is 1630-1650℃.

2. The method for increasing furnace life according to claim 1, characterized in that: In step 4), the components to be tested are carbon, manganese, phosphorus, and sulfur.

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