A method for high manganese molten iron converter smelting low manganese high temperature tapping

Abstract

The present application belongs to the field of metallurgy, and particularly relates to a method for high-manganese hot metal converter smelting low-manganese high-temperature tapping. 3 The present application adopts double-slag method smelting, and the oxygen supply intensity of the first blowing is controlled at 4.5-5.0 Nm 3 / t / min, the iron-based slagging agent is added to promote slagging, the molten pool temperature is controlled at ≤1550 ℃ and the carbon content is controlled at ≤0.10% at the end of the first blowing; the oxygen supply intensity of the second blowing is controlled at 5.0-5.5 Nm / t / min, the silicon-aluminum-carbon temperature raising agent is added to re-slag and raise the temperature, and the final slag basicity is controlled at 2.0-2.5; by the method, when the hot metal manganese content is high, the converter smelting can ensure that the molten steel manganese content is ≤0.05% and the tapping temperature is 1650-1680 ℃ at the end of the converter.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of metallurgy, and particularly relates to a method for high-temperature tapping of low-manganese molten high-manganese iron in a converter. BACKGROUND

[0002] Industrial pure iron is a kind of metal material with very low carbon content, and its chemical composition is mainly iron, and other alloy elements are as low as possible. The room temperature structure of industrial pure iron is mainly ferrite, and industrial pure iron has the characteristics of soft texture, high toughness, good ductility, excellent electromagnetic performance and the like. The smelting of industrial pure iron generally adopts a process route of converter-LF refining furnace-RH refining furnace-continuous casting. However, due to the problem of mineral sources, the manganese content of the molten iron is relatively high. For the molten iron with manganese content > 0.40%, the molten iron + ordinary scrap steel is smelted, the ordinary single-slag method is adopted, the manganese content at the end point of the converter can be reduced to about 0.15%, the special double-slag method + supplementary blowing process is adopted, the manganese content at the end point of the converter can be reduced to 0.05%, but the end point temperature is basically below 1600℃. The carbon content and the alloy element content of industrial pure iron are extremely low, and the liquidus temperature is usually high. In order to ensure the smooth production, the temperature rising treatment is usually carried out in the LF refining process, but the process takes a long time, and it is difficult to match the production rhythm of the converter, the RH refining furnace and the continuous casting.

[0003] Chinese patent CN109943680A discloses a production method of ultra-low-carbon, low-silicon, low-manganese and low-aluminum steel continuous casting billet, adopts converter double-slag method smelting, and the manganese content of the molten iron is ≤0.35%; the oxygen supply intensity of top blowing is controlled to be 2.5-2.8 Nm 3 / t / min, the gas supply intensity of bottom blowing is controlled to be 0.04-0.08 Nm 3 / t / min; the smelting process adopts lime, light-burned dolomite, fluorite and sintered ore to make slag; the one-time slagging opportunity is controlled to be 30-35% of the oxygen blowing amount, the blowing temperature is controlled to be 1380-1440℃, the slag basicity is controlled to be 1.8-2.5, and the slagging rate is >50%; the blowing end point temperature is controlled to be 1630-1660℃, the end point carbon content is controlled to be 0.03-0.05%, and the end point manganese content can be controlled to be ≤0.05%. The patent requires that the manganese content of the molten iron is ≤0.35%.

[0004] Chinese patent CN111440916A is directed to molten iron with manganese content > 0.40% entering the furnace, selecting a converter with high carbon-oxygen product for smelting, adjusting the bottom blowing control mode according to the carbon-oxygen product, adjusting the ratio of molten iron and scrap steel, using a low-high-low-high-low oxygen lance control mode; adding iron skin balls, dolomite, etc. during the early and late stages of blowing to control the converter smelting process, controlling the end point temperature between 1590-1630℃, and the end point oxygen between 1000PPM to 1300PPM, so that the manganese content of the molten steel in the continuous casting machine is stably below 0.03%. However, the carbon content of the molten iron in the patent is 0.30%≤C≤0.50%, which cannot be used for smelting of molten iron with extremely low carbon content; and the smelting process control and feeding process detection and control method are complex. SUMMARY

[0005] The industrial pure iron involved in the present application requires manganese content ≤0.05%, and the molten steel carbon content ≤0.005%. In order to ensure that the molten steel meets the standards, the industrial pure iron adopts the process route of converter→LF refining furnace→RH refining furnace→continuous casting. Due to the extremely low carbon content and alloy element content of the industrial pure iron, the liquidus temperature is 1532℃. In order to ensure smooth casting, the continuous casting temperature of the molten steel is 1550-1570℃ (the opening casting furnace is 1560-1580℃). Considering the temperature drop during the processing, the end temperature of the RH treatment is reversely calculated to be 1580-1610℃ (the opening casting furnace is 1600-1630℃), and the end temperature of the LF treatment is 1630-1670℃ (the opening casting furnace is 1660-1700℃). Using the conventional process for smelting, in order to ensure the manganese content of the molten steel at the end of the converter, the end temperature of the converter is generally below 1600℃, the temperature at the LF station is basically 1530-1550℃, the temperature rise is about 100℃, the power-on time is basically about 50min, and the processing time of the LF refining furnace is about 65min. The processing time of the converter, the RH refining furnace and the continuous casting is generally about 40min, and the production rhythm is difficult to match. Therefore, it is necessary to increase the tapping temperature of the converter, and reduce the power-on time of the LF furnace. It is calculated that the tapping temperature of the converter is above 1650℃, and the processing time of the refining furnace can be controlled within 40min, which meets the production requirements.

[0006] Therefore, the purpose of the present application is to provide a method for smelting low-manganese high-temperature tapping of high-manganese molten iron in a converter. The method uses a converter for smelting, controls the temperature, slag composition and molten steel composition during the smelting process, and performs multiple slag making. Finally, the end temperature is ≥1650℃, and the manganese content of the molten steel at the end is ≤0.05%.

[0007] A method for smelting low-manganese high-temperature tapping of high-manganese molten iron in a converter, the process flow is: adding scrap steel and molten iron→first blowing→first slagging→second blowing→second slagging→tapping, the specific operation steps are:

[0008] Step one, empty furnace smelting, adding scrap steel, adding molten iron, molten iron ratio 80-90%, scrap steel ratio 10-20%; molten iron manganese content 0.35-0.60%, scrap steel manganese content 0.3-0.6%.

[0009] Step two, first blowing, top blowing oxygen intensity controlled at 4.5-5.0 Nm 3 / t / min, gun position controlled at 1.6-2.0 m; first blowing adopts light-burned dolomite and lime combined slagging, light-burned dolomite addition amount controlled at 15-40 kg / t, lime addition amount controlled at 15-40 kg / t, and 10-30 kg / t of iron series slagging agent is added to prevent slag from drying, first blowing ending bath temperature controlled at 1550℃ or less, while molten steel carbon content ≤0.10%, molten steel manganese content ≤0.08%.

[0010] Step three, first slagging, first slagging amount ≥90%.

[0011] Step four, second blowing, top blowing oxygen intensity controlled at 5.0-5.5 Nm 3 / t / min, gun position controlled at 1.3-1.6 m; 2-8 kg / t of silicon aluminum carbon ball, 3-10 kg / t of light-burned dolomite and 0-5 kg / t of lime is added.

[0012] Step five, second slagging, slagging amount 40-60%.

[0013] Step six, tapping, tapping temperature controlled at 1650-1680℃, tapping carbon content ≤0.05%.

[0014] Further, as preferred, in step one, before adding molten iron and scrap steel, after the last furnace slag splashing and furnace protection, all the slag is poured out, requiring the converter to be empty and no slag left.

[0015] Further, as preferred, the composition of the slagging agent is CaO·2Fe2O3: 50-60%, CaO·Fe2O3: 40-50%, and some unavoidable impurities. The molten steel composition at the end of first blowing is: [C] ≤0.10%, [Mn] ≤0.08%, [P] 0.005-0.015%; the slag composition is CaO: 25%-40%, MgO: 10%-20%, SiO2: 7%-15%, FeO: 12%-25%, MnO: 5%-15%, and some unavoidable impurities, and the slag basicity is 2.5-3.5.

[0016] Further, as preferred, in step four, the components of the silicon-aluminum-carbon ball are C: 20-30%, Si: 30-40%, Al: 30-40%, and inevitable impurities. The components of the molten steel at the end of the secondary blowing are [C] 0.03-0.05%, [Mn] 0.02-0.05%, [P] ≤0.015%; the components of the slag are CaO: 20-35%, MgO: 10-20%, SiO2: 10-20%, FeO: 12-25%, MnO: 5-15%, Al2O3: 3-8%, and some inevitable impurities, and the slag basicity is 2.0-2.5.

[0017] The present application has the following advantages:

[0018] (1) Strictly controlling the process temperature and the slag components, adding the iron-based slagging agent in the primary blowing process, promoting the slag melting, effectively preventing splashing, and participating in the manganese and phosphorus removal reactions;

[0019] (2) The carbon content of the molten steel at the end of the primary blowing is required to be ≤0.10%, and the temperature is controlled within 1550°C, and the manganese content of the molten steel can be controlled within 0.08%;

[0020] (3) Adding the silicon-aluminum-carbon ball in the secondary blowing process, which not only serves as a heating element to ensure the end temperature, but also generates SiO2 after silicon oxidation, generates Al2O3 after aluminum oxidation, and combines with MnO in the slag to generate MnO·SiO2 and MnO·Al2O3 solid solution, thereby reducing the MnO activity of the slag and promoting manganese removal.

[0021] (4) The present application can realize the smelting of high-temperature low-manganese steel under high oxygen supply intensity, and the oxygen supply intensity in the smelting process can be controlled within 4.5-5.5 Nm 3 / t / min. DETAILED DESCRIPTION

[0022] The present application is described in detail in the following specific embodiments.

[0023] In the following specific embodiments, the Mn content of the molten iron and scrap steel is >0.40%; the process flow of the converter smelting is: adding scrap steel, adding molten iron→ primary blowing→ primary slagging→ secondary blowing→ secondary slagging→ tapping.

[0024] Adding scrap steel and adding molten iron: the 120t converter is used for air furnace smelting, and the molten iron ratio is 80-85% and the scrap steel ratio is 15-20%. After the previous furnace is slag splashed to protect the furnace, all the slag is poured out, and the converter is required to be empty and no slag is left.

[0025] Primary blowing: the top blowing oxygen supply intensity is controlled within 35000 Nm 3 / h, constant pressure variable lance position smelting, lance position control at 1.6-2.0 m; primary blowing adopts light-burned dolomite and lime combined slagging, and adds iron-based slagging agent to prevent slag from drying back, the composition of the iron-based slagging agent is CaO-2Fe2O3: 50-60%, CaO-Fe2O3: 40-50%, and some unavoidable impurities. The molten pool temperature is controlled at 1530-1550°C at the end of primary blowing, while the molten steel [C] is 0.05-0.06%, [Mn] is 0.05-0.06%, and [P] is 0.005-0.015%; the slag composition is CaO: 25%-40%, MgO: 10%-20%, SiO2: 7%-15%, FeO: 12%-25%, MnO: 5%-15%, and some unavoidable impurities, and the slag basicity is 2.5-3.5.

[0026] Primary slagging: the primary slagging amount is ≥90%.

[0027] Secondary blowing: the top blowing oxygen supply intensity is controlled at 39000 Nm 3 / h, constant pressure variable lance position smelting, lance position control at 1.3-1.6 m; adding silicon aluminum carbon balls, light-burned dolomite and lime, the composition of the silicon aluminum carbon balls is C: 20-30%, Si: 30-40%, Al: 30-40%, and unavoidable impurities.

[0028] Secondary slagging: secondary slagging operation is carried out after the secondary blowing is completed, the slagging amount is 40-60%, and the molten steel is tapped after the secondary slagging is completed. The molten steel composition after the secondary blowing is completed is: [C] is 0.03-0.05%, [Mn] is 0.02-0.05%, and [P] is ≤0.015%; the slag composition is CaO: 20%-35%, MgO: 10%-20%, SiO2: 10%-20%, FeO: 12%-25%, MnO: 5%-15%, Al2O3: 3-8%, and some unavoidable impurities, and the slag basicity is 2.0-2.5. The tapping temperature is controlled at 1650-1680°C.

[0029] Example 1:

[0030] The 120 t converter adopts empty furnace smelting, and is charged with 110 t hot metal + 20 t scrap steel, the silicon content of the converter hot metal is 0.35%, the manganese content of the hot metal is 0.42%, and the manganese content of the scrap steel is 0.45%.

[0031] Primary blowing, oxygen supply flow is controlled at 35000 Nm 3 / h, constant pressure variable gun position smelting, gun position control at 1.6-2.0 m, smelting process adding light-burned dolomite 2500 kg, lime 2800 kg, iron series slagging agent 2800 kg; the composition of the iron series slagging agent is: CaO-2Fe2O3: 56%, CaO-Fe2O3: 43%, and some unavoidable impurities. The temperature of the molten steel at the end of the primary blowing is 1543°C, and the composition of the slag is CaO: 39.7%, MgO: 15.2%, SiO2: 12.8%, FeO: 18.5%, MnO: 13.2%, basicity 3.1, and unavoidable impurities; the composition of the molten steel is [C] 0.06%, [Mn] 0.052%, [P] 0.008%.

[0032] Primary slagging, primary slagging amount is 90%.

[0033] Secondary blowing, oxygen supply flow control at 39000 Nm 3 / h, constant pressure variable gun position smelting, gun position control at 1.3-1.6 m; smelting process adding silicon aluminum carbon ball 600 kg, light-burned dolomite 500 kg, lime 200 kg; the composition of the silicon aluminum carbon ball is C: 28.5%, Si: 39.7%, Al: 30.7%, and unavoidable impurities. After the secondary blowing is completed, slagging operation is performed, the amount of slagging is 51%, and after the slagging is completed, the molten steel is tapped. The composition of the slag is CaO: 31.7%, MgO: 16.3%, SiO2: 13.8%, FeO: 18.8%, MnO: 8.9%, Al2O3: 7.3%, and some unavoidable impurities, the basicity of the slag is 2.3. The composition of the molten steel is [C] 0.03%, [Mn] 0.03%, [P] 0.009%, and the temperature of the molten steel is 1660°C.

[0034] Example 2:

[0035] The 120 t converter is smelted with empty furnace and charged with 108 t of molten iron + 22 t of scrap steel, the silicon content of the molten iron in the converter is 0.28%, the manganese content of the molten iron is 0.48%, and the manganese content of the scrap steel is 0.47%.

[0036] Primary blowing, oxygen supply flow control at 35000 Nm 3 / h, constant pressure variable lance position smelting, smelting lance position control at 1.6-2.0 m, smelting process adding light-burned dolomite 2400 kg, lime 2600 kg, iron-based slagging agent 2500 kg, the composition of the iron-based slagging agent is: CaO-2Fe2O3: 52%, CaO-Fe2O3: 46%, and some inevitable impurities. The temperature of the molten steel is 1537℃, the composition of the slag is CaO: 38.9%, MgO: 14.7%, SiO2: 11.7%, FeO: 20.3%, MnO: 12.9%, basicity 3.3, and inevitable impurities; the composition of the molten steel is [C] 0.05%, [Mn] 0.058%, [P] 0.006%.

[0037] Once the slag is poured, the amount of the first slag pouring is 91%.

[0038] Secondary blowing, the oxygen supply flow is controlled at 39000 Nm 3 / h, smelting process adding silicon aluminum carbon balls 700 kg, light-burned dolomite 600 kg, lime 300 kg; the composition of the silicon aluminum carbon balls is C: 25.6%, Si: 38.7%, Al: 33.9%, and inevitable impurities. After the secondary blowing is completed, the slag pouring operation is performed, the amount of the slag pouring is 47%, and the molten steel is discharged after the slag pouring is completed. The composition of the slag is CaO: 32.3%, MgO: 15.7%, SiO2: 13.5%, FeO: 19.7%, MnO: 9.3%, Al2O3: 7.6%, and some inevitable impurities, and the basicity of the slag is 2.4. The composition of the molten steel is [C] 0.032%, [Mn] 0.032%, [P] 0.008%, and the temperature of the molten steel is 1662℃.

[0039] Comparative Example 1

[0040] The 120 t converter is smelted with an empty furnace and is charged with 110 t of molten iron + 20 t of scrap steel, the silicon content of the molten iron of the converter is 0.36%, the manganese content of the molten iron is 0.41%, and the manganese content of the scrap steel is 0.44%.

[0041] Primary blowing, the oxygen supply flow is controlled at 35000 Nm 3 / h, constant pressure variable lance position smelting, smelting lance position control at 1.6-2.0 m, smelting process adding light-burned dolomite 2400 kg, lime 2600 kg, iron-based slagging agent 2500 kg, the composition of the iron-based slagging agent is: CaO-2Fe2O3: 52%, CaO-Fe2O3: 46%, and some inevitable impurities. The temperature of the molten steel is 1537℃, the composition of the slag is CaO: 38.9%, MgO: 14.7%, SiO2: 11.7%, FeO: 20.3%, MnO: 12.9%, basicity 3.3, and inevitable impurities; the composition of the molten steel is [C] 0.05%, [Mn] 0.058%, [P] 0.006%.

[0042] Once tapping, the amount of once tapping is 90%.

[0043] Secondary blowing, the oxygen flow is controlled at 39000Nm 3 / h, 500kg of light-burned dolomite and 200kg of lime are added during the smelting process. Once tapping is performed after the secondary blowing, the amount of once tapping is 49%, and the tapping is finished. The composition of the slag is CaO: 37.4%, MgO: 14.7%, SiO2: 10.4%, FeO: 31.7%, MnO: 4.6%, and some inevitable impurities, and the slag basicity is 3.6. The composition of the molten steel is [C] 0.03%, [Mn] 0.07%, [P] 0.005%, and the temperature of the molten steel is 1658℃.

[0044] Compared with Example 1, the silicon-aluminum-carbon balls are not added during the secondary blowing process of the converter, the end-point slag basicity is high, the slag oxidizability is high, and the manganese content of the molten steel cannot meet the requirements.

[0045] Comparative Example 2:

[0046] The 120t converter is smelted with an empty furnace and is loaded with 108t of molten iron + 22t of scrap steel. The silicon content of the molten iron of the converter is 0.29%, the manganese content of the molten iron is 0.47%, and the manganese content of the scrap steel is 0.45%.

[0047] Primary blowing, the oxygen flow is controlled at 35000Nm 3 / h, constant pressure and variable lance position smelting, the smelting lance position is controlled at 1.6-2.0m; 2400kg of light-burned dolomite, 2600kg of lime, and 2500kg of ore are added during the smelting process, the composition of the ore is Fe2O3: 75%, FeO: 13%, SiO2: 3%, CaO: 7%, and some impurities; spitting occurs when 45% of oxygen is blown, at which time 600kg of raw dolomite is added to press the slag; after the spitting is finished, the smelting lance position is increased to 2.0m to assist in slagging, but the overall slagging is poor. After the primary blowing is finished, the temperature of the molten steel is 1537℃, the composition of the slag is CaO: 39.2%, MgO: 15.2%, SiO2: 12.1%, FeO: 20.5%, MnO: 9.7%, the basicity is 3.2, and some inevitable impurities; the composition of the molten steel is [C] 0.053%, [Mn] 0.11%, [P] 0.007%.

[0048] Once tapping, the amount of once tapping is 88%.

[0049] Secondary blowing, the oxygen flow is controlled at 39000Nm 3 / h, 700 kg of silicon-aluminum-carbon balls, 600 kg of light-burned dolomite, and 300 kg of lime were added during the smelting process. The composition of the silicon-aluminum-carbon balls was C: 25.7%, Si: 38.2%, Al: 33.8%, and inevitable impurities. The slag was tapped at 50% of the total amount after the end of the secondary blowing, and the molten steel was tapped after the end of the slag tapping. The composition of the slag was CaO: 32.9%, MgO: 15.4%, SiO2: 13.6%, FeO: 19.2%, MnO: 8.5%, Al2O3: 7.2%, and inevitable impurities, and the slag basicity was 2.42. The composition of the molten steel was [C] 0.03%, [Mn] 0.062%, and [P] 0.010%, and the temperature of the molten steel was 1661°C.

[0050] In the primary blowing process of the comparative example, no iron-based slagging agent was added, ore was used to control the temperature and promote slagging, spitting occurred in the early stage of smelting, and raw dolomite was used to press the slag, and slag dryness occurred. The manganese content of the molten steel at the end of the primary blowing was high, and the manganese content of the final molten steel was also high.

[0051] Comparative Example 3:

[0052] The 120 t converter was used for smelting with an empty furnace, and 110 t of molten iron and 20 t of scrap steel were charged. The silicon content of the molten iron in the converter was 0.36%, the manganese content of the molten iron was 0.41%, and the manganese content of the scrap steel was 0.45%.

[0053] The oxygen flow rate was controlled at 35000 Nm 3 / h during the primary blowing, and the smelting lance position was controlled at 1.6-2.0 m. 2500 kg of light-burned dolomite, 2800 kg of lime, and 2200 kg of iron-based slagging agent were added during the smelting process. The composition of the iron-based slagging agent was CaO·2Fe2O3: 56%, CaO·Fe2O3: 43%, and inevitable impurities. The temperature of the molten steel was 1580°C, the composition of the slag was CaO: 39.3%, MgO: 15.6%, SiO2: 12.6%, FeO: 18.7%, MnO: 11.8%, and the basicity was 3.1, and inevitable impurities; the composition of the molten steel was [C] 0.18%, [Mn] 0.089%, and [P] 0.016%.

[0054] The slag was tapped once, and the amount of the first slag tapping was 90%.

[0055] The oxygen flow rate was controlled at 39000 Nm 3The silicon-aluminum-carbon ball 600 kg, light-burned dolomite 500 kg, and lime 200 kg are added in the smelting process. The composition of the silicon-aluminum-carbon ball is C: 28.5%, Si: 39.7%, Al: 30.7%, and inevitable impurities. The secondary blowing is ended, and the slag is tapped, and the amount of the tapped slag is 52%. The steel is tapped after the end of the slag tapping. The composition of the slag is CaO: 31.3%, MgO: 16.7%, SiO2: 14.2%, FeO: 19.3%, MnO: 7.9%, Al2O3: 7.5%, and some inevitable impurities, and the slag basicity is 2.2. The composition of the molten steel is [C] 0.03%, [Mn] 0.067%, and [P] 0.018%, and the temperature of the molten steel is 1660°C.

[0056] The temperature of the molten pool and the carbon content at the end of the primary blowing of the comparative example are not controlled according to the requirements, the manganese content of the molten steel at the end of the primary blowing does not meet the requirements, and the manganese content of the molten steel at the end of the smelting also does not meet the requirements.

[0057] The above merely describes the preferred embodiments of the present application, but the protection scope of the present application is not limited to this. Any person skilled in the art, according to the technical solution and concept of the present application, makes equivalent replacement or change within the technical range disclosed by the present application, and should be covered in the protection scope of the present application.

Claims

1. A method of high manganese hot metal converter smelting with low manganese hot metal tapping at high temperature, characterized in that, The process flow is: adding scrap steel, mixing with molten iron→ primary blowing→ primary slagging→ secondary blowing→ secondary slagging→ tapping, the specific operation steps are: Step one, empty furnace smelting, adding scrap steel, mixing with molten iron, the ratio of molten iron is 80-90%, the ratio of scrap steel is 10-20%; among them, the manganese content of molten iron is 0.35-0.60%, the manganese content of scrap steel is 0.3-0.6%; Step two, once blowing, top blowing oxygen intensity control in 4.5~5.0Nm 3 / t / min, gun position control in 1.6~2.0m; once blowing adopts light-burned dolomite and lime combined slagging, and adds 10~30kg / t iron series slagging agent to prevent slag from drying back, once blowing ends with the molten pool temperature controlled within 1550℃, while the molten steel carbon content ≤0.10%, and the molten steel manganese content ≤0.08%; wherein, the composition of the iron series slagging agent is CaO·2Fe2O3: 50~60%, CaO·Fe2O3: 40~50%, and some unavoidable impurities; Step three, primary slagging, the amount of primary slagging is ≥90%; Step four, secondary blowing, the top blowing oxygen intensity is controlled at 5.0-5.5 Nm 3 / t / min, the gun position is controlled at 1.3-1.6 m; the silicon-aluminum-carbon balls, light-burned dolomite and lime are added; wherein the composition of the silicon-aluminum-carbon balls is C: 20-30%, Si: 30-40%, Al: 30-40%, and inevitable impurities; Step five, secondary slagging, the amount of slagging is 40-60%; Step six, tapping, the tapping temperature is controlled at 1650-1680℃, the carbon content is ≤0.05%.

2. The process for high manganese hot metal converter smelting low manganese high temperature tapping as claimed in claim 1 wherein, The adding amount of light-burned dolomite in step two is controlled at 15-40kg / t, and the adding amount of lime is controlled at 15-40kg / t.

3. The process for high manganese hot metal converter smelting low manganese high temperature tapping as claimed in claim 1 wherein, The adding amount of silicon-aluminum-carbon ball is 2-8kg / t, the adding amount of light-burned dolomite is 3-10kg / t, and the adding amount of lime is 0-5kg / t.

4. The process for high manganese hot metal converter smelting low manganese hot metal with high temperature tapping as claimed in claim 1 wherein, The composition of molten steel after primary blowing is: [C]≤0.10%, [Mn]≤0.08%, [P]0.005-0.015%.

5. The process for high manganese hot metal converter smelting low manganese high temperature tapping as claimed in claim 1 wherein, The composition of slag after primary blowing is CaO: 25%-40%, MgO: 10%-20%, SiO2: 7%-15%, FeO: 12%-25%, MnO: 5%-15%, and some unavoidable impurities, the slag basicity is 2.5-3.

5.

6. The process for high manganese hot metal converter smelting low manganese hot metal with high temperature tapping as claimed in claim 1 wherein, The composition of molten steel after secondary blowing is: [C]0.03-0.05%, [Mn]0.02-0.05%, [P]≤0.015%.

7. The process for high manganese hot metal converter smelting low manganese high temperature tapping as claimed in claim 1 wherein, The composition of slag after secondary blowing is CaO: 20%-35%, MgO: 10%-20%, SiO2: 10%-20%, FeO: 12%-25%, MnO: 5%-15%, Al2O3: 3-8%, and some unavoidable impurities, the slag basicity is 2.0-2.5.