Medium carbon ferromanganese formula and preparation process thereof

Abstract

The invention discloses a medium-carbon ferromanganese formula and a preparation process thereof, and belongs to the technical field of metallurgy. The preparation process comprises the following steps: mixing South African carbonic acid powder, Gabane ore, Australian ore and coke powder to obtain a mixed material, adding the mixed material into a sintering machine, and sintering under the ignition of submerged arc furnace gas to obtain sintered ore; the method comprises the following steps: adding Gabane ore, Australian ore, South African semi-carbonate ore and South African medium iron ore into a drying kiln, and heating and drying the materials by using heat generated by combustion of gas in a submerged arc furnace to obtain dried lump ore; the coke is screened, and the coke with the optimized size fraction is obtained and serves as a reducing agent; mixing the sintered ore with the dried lump ore to obtain a manganese ore raw material; a manganese ore raw material and a reducing agent are mixed to obtain a mixed material, then the mixed material is added into an electric furnace to be smelted, and the medium-carbon ferromanganese is obtained. The medium-carbon ferromanganese obtained by the formula and the preparation process is stable in component, high in manganese recovery rate and low in smelting power consumption.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of metallurgy, and more particularly relates to a medium-carbon ferromanganese formula and a preparation process thereof. BACKGROUND

[0002] Medium-carbon ferromanganese is an important alloy raw material in the steel industry, and its core is to reduce manganese oxides in manganese ore and combine them with iron to form an alloy with a moderate carbon content. The mainstream smelting process currently includes the blast furnace method and the electric furnace method. The blast furnace method has a high content of harmful phosphorus in the product due to a large amount of coke used in the smelting process, which restricts the variety and cost control of subsequent steel smelting. The electric furnace method also has the problems of high smelting power consumption and low manganese element recovery rate, which limits the economy. Therefore, how to avoid this phenomenon is the key to solving the problem. For example, a Chinese invention patent with the publication number CN106367591B discloses a method for preparing low-phosphorus medium-carbon ferromanganese by high-carbon ferromanganese molten salt decarburization and dephosphorization. The invention uses molten salt to decarburize solid high-carbon ferromanganese, which has low temperature and high efficiency, and can also solve the problem of dephosphorization and decarburization of non-national standard high-phosphorus high-carbon ferromanganese obtained by smelting high-phosphorus manganese ore. However, the problem of high smelting power consumption remains to be solved. SUMMARY

[0003] TECHNICAL PROBLEM In view of the deficiencies of the prior art, the present application provides a medium-carbon ferromanganese formula and a preparation process thereof, which has stable composition, high manganese recovery rate, and low smelting power consumption.

[0004] TECHNICAL SCHEME In order to solve the above problems, the technical scheme adopted by the present application is as follows: A medium-carbon ferromanganese formula, in terms of mass parts, comprises: 70-80 parts of manganese ore raw material, 12-18 parts of reducing agent. The manganese ore raw material is mixed by sintered ore and dried lump ore in a mass ratio of 1.5-2:1. The reducing agent is coke. The medium-carbon ferromanganese product prepared by using the formula satisfies: Mn 75-85%, C 1.0-4.0%, P 0.02-0.06%, and the balance is iron and unavoidable impurities, in terms of weight percentage.

[0005] Further, the preparation raw material of the sintered ore comprises, in terms of mass parts: 40-60 parts of South African carbon powder, 10-30 parts of Gabon ore, 10-30 parts of Australian ore, and 5-8 parts of coke powder.

[0006] Further, the chemical composition of the sintered ore satisfies: Mn 43-46%, Fe 7-20%, SiO2 5-10%, P 0.02-0.05%, CaO 5-15%, MgO 1-4%, Al2O3 0.5-2.5% by weight percentage, and the rest is impurities, and the basicity is between 1.0-2.0.

[0007] Further, the dried lump ore is composed of the following mass parts of lump ore: 5-10 parts of Gabon ore, 5-10 parts of Australian ore, 3-6 parts of South African semi-carbonate ore, and 10-15 parts of South African medium iron ore.

[0008] Further, the particle size distribution of the reducing agent coke is: 10-20% of >30mm, 50-60% of 20-30mm, 25-30% of 10-20mm, 2-5% of 5-10mm, and 1-3% of <5mm by mass percentage.

[0009] Further, a preparation process of a medium-carbon ferromanganese formula, comprising the following steps: Step one: mix South African carbonate powder, Gabon ore, Australian ore, and coke powder to obtain a mixture, and add the mixture into a sintering machine to perform sintering under the ignition of the furnace gas, control the sintering temperature to be 1100-1200℃, and the sintering time to be 2-3h, and after cooling, crush to 5-50mm to obtain a sintered ore; Step two: add Gabon ore, Australian ore, South African semi-carbonate ore, and South African medium iron ore into a drying kiln, and use the heat generated by the combustion of the furnace gas to heat and dry the materials, control the drying temperature to be 200-300℃, so that the moisture of the dried lump ore is ≤1%, and obtain the dried lump ore; Step three: screen the coke to obtain particle size optimized coke as a reducing agent; Step four: mix the sintered ore and the dried lump ore at a mass ratio of 1.5-2:1 to obtain a manganese ore raw material; Step five: mix the manganese ore raw material and the reducing agent to obtain a mixture, and then add the mixture into an electric furnace to smelt to obtain a medium-carbon ferromanganese.

[0010] Further, the mixture in step five is uniformly distributed around the three-phase electrode when entering the electric furnace, and the material surface in the center region of the three-phase electrode with intense reaction is higher than the surrounding region by 300-500mm.

[0011] Further, the working position of the three-phase electrode in step five is controlled to be at a horizontal position of 1500-2000mm from the taphole, and the reaction temperature is controlled to be 1450-1550℃.

[0012] Furthermore, in step five, the electrode current of the electric furnace is controlled within the range of 130-160kA, the secondary voltage is controlled within the range of 150-210V, and the power factor is controlled within the range of 0.85-0.86.

[0013] Furthermore, the chemical composition of the slag obtained after smelting in step five, by weight percentage, satisfies the following: Mn 8-14%, SiO2 22-32%, CaO 25-40%, MgO 4-8%, Al2O3 8-18%, with the remainder being impurities, and the alkalinity is between 1.2 and 1.6.

[0014] Beneficial technical effects (1) By optimizing the furnace charge structure, accurately controlling the electric furnace operating parameters and controlling the appropriate reaction temperature, the power consumption in the smelting process is effectively reduced, resulting in lower unit product power consumption and improved energy utilization efficiency.

[0015] (2) By controlling the slag alkalinity within a reasonable range, the loss of manganese in the slag is reduced, the manganese recovery rate is significantly improved, which is significantly better than the traditional process, thus improving the utilization rate of raw materials and reducing production costs.

[0016] (3) Sintering, drying, and rationally proportioning the manganese ore, as well as optimizing the coke particle size, make the raw material composition of the furnace more uniform and stable. With precise electrical control technology, a medium-carbon ferromanganese product with stable composition is finally obtained, reducing composition fluctuations, improving product consistency, and meeting the strict requirements of downstream steel smelting. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are described clearly and completely. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0018] To better understand the above technical solutions, the following will provide a detailed explanation of the technical solutions in conjunction with specific embodiments.

[0019] Example 1 A process for preparing medium-carbon ferromanganese includes the following steps: (1) Mix 40 parts by weight of South African carbonate powder, 10 parts by weight of Gabonese ore, 10 parts by weight of Australian ore and 5 parts by weight of coke powder to obtain a mixture. Add the mixture to a sintering machine and sinter under the ignition of coal gas in a submerged arc furnace. Control the sintering temperature at 1100℃ and the sintering time at 2h. After cooling, crush it to 5mm to obtain sintered ore. (2) Add 5 parts by weight of Gabonite, 5 parts by weight of Australian ore, 3 parts by weight of South African semi-carbonate ore and 10 parts by weight of South African iron ore into a drying kiln, use the heat generated by the combustion of coal gas in the electric arc furnace to heat and dry the material, control the drying temperature to 200℃, so that the moisture content of the dried lump ore is ≤1%, and obtain the dried lump ore. (3) The coke is screened to obtain coke with optimized particle size, which is used as a reducing agent. The particle size distribution of the coke is as follows by mass percentage: >30mm accounts for 10%, 20-30mm accounts for 60%, 10-20mm accounts for 27%, 5-10mm accounts for 2%, and <5mm accounts for 1%. (4) Mix the sintered ore and the dried lump ore at a mass ratio of 1.5:1 to obtain manganese ore raw material; (5) Mix 70 parts by mass of manganese ore raw material and 12 parts by mass of reducing agent to obtain a mixture. Then add the mixture into the electric furnace and distribute it evenly around the three-phase electrodes. At the same time, the material surface in the central area of ​​the three-phase electrodes where the reaction is intense is 300 mm higher than the surrounding area. Control the working position of the three-phase electrodes to be 1500 mm away from the tapping hole. Control the reaction temperature at 1450℃. Control the electrode current of the electric furnace to 130 kA, the secondary voltage to 150 V, and the power factor to 0.85. Smelt the mixture to obtain medium carbon ferromanganese.

[0020] Testing revealed that the medium-carbon ferromanganese product prepared using the formula in this embodiment meets the following weight percentage requirements: Mn 75%, C 1.0%, P 0.02%, with the remainder being iron and unavoidable impurities. The chemical composition of the slag obtained after smelting meets the following weight percentage requirements: Mn 8%, SiO2 22%, CaO 25%, MgO 4%, Al2O3 8%, with the remainder being impurities, and the basicity is 1.2. The power consumption for actual heavy smelting is reduced to 2370 kWh / t, and the manganese recovery rate can reach 93.36%.

[0021] Example 2 A process for preparing medium-carbon ferromanganese includes the following steps: (1) Mix 60 parts by weight of South African carbonate powder, 30 parts by weight of Gabonese ore, 30 parts by weight of Australian ore and 8 parts by weight of coke powder to obtain a mixture. Add the mixture to a sintering machine and sinter under the ignition of coal gas in a submerged arc furnace. Control the sintering temperature at 1200℃ and the sintering time at 3h. After cooling, crush it to 50mm to obtain sintered ore. (2) Add 10 parts by weight of Gabonite, 10 parts by weight of Australian ore, 6 parts by weight of South African semi-carbonate ore and 15 parts by weight of South African iron ore into a drying kiln, use the heat generated by the combustion of coal gas in the electric arc furnace to heat and dry the material, control the drying temperature to 300℃, so that the moisture content of the dried lump ore is ≤1%, and obtain the dried lump ore. (3) The coke is screened to obtain coke with optimized particle size, which is used as a reducing agent. The particle size distribution of the coke is as follows by mass percentage: >30mm accounts for 17%, 20-30mm accounts for 50%, 10-20mm accounts for 25%, 5-10mm accounts for 5%, and <5mm accounts for 3%. (4) Mix the sintered ore and the dried lump ore at a mass ratio of 2:1 to obtain manganese ore raw material; (5) Mix 80 parts by mass of manganese ore raw material and 18 parts by mass of reducing agent to obtain a mixture. Then add the mixture to the electric furnace and distribute it evenly around the three-phase electrodes. At the same time, the material surface in the central area of ​​the three-phase electrodes where the reaction is intense is 500 mm higher than the surrounding area. Control the working position of the three-phase electrodes to be 2000 mm away from the tapping hole. Control the reaction temperature at 1550℃. Control the electrode current of the electric furnace to 160 kA, the secondary voltage to 210 V, and the power factor to 0.86. Smelt the mixture to obtain medium carbon ferromanganese.

[0022] Testing revealed that the medium-carbon ferromanganese product prepared using the formula in this embodiment met the following weight percentage requirements: Mn 85%, C 4.0%, P 0.06%, with the remainder being iron and unavoidable impurities. The chemical composition of the slag obtained after smelting met the following weight percentage requirements: Mn 11%, SiO2 32%, CaO 38%, MgO 8%, Al2O3 18%, with the remainder being impurities, and the basicity being 1.6. The power consumption for actual heavy smelting was reduced to 2255 kWh / t, and the manganese recovery rate reached 94.36%.

[0023] Example 3 A process for preparing medium-carbon ferromanganese includes the following steps: (1) Mix 43 parts by weight of South African carbonate powder, 13 parts by weight of Gabonese ore, 13 parts by weight of Australian ore and 6 parts by weight of coke powder to obtain a mixture. Add the mixture to a sintering machine and sinter under the ignition of ferroalloy gas. Control the sintering temperature at 1100℃ and the sintering time at 2h. After cooling, crush to 15mm to obtain sintered ore. (2) Add 6 parts by weight of Gabonite, 6 parts by weight of Australian ore, 4 parts by weight of South African semi-carbonate ore and 11 parts by weight of South African iron ore into a drying kiln, use the heat generated by the combustion of coal gas in the electric arc furnace to heat and dry the material, control the drying temperature to 200℃, so that the moisture content of the dried lump ore is ≤1%, and obtain the dried lump ore. (3) The coke is screened to obtain coke with optimized particle size, which is used as a reducing agent. The particle size distribution of the coke is as follows by mass percentage: >30mm accounts for 11%, 20-30mm accounts for 59%, 10-20mm accounts for 25%, 5-10mm accounts for 3%, and <5mm accounts for 2%. (4) Mix the sintered ore and the dried lump ore at a mass ratio of 1.5:1 to obtain manganese ore raw material; (5) Mix 72 parts by mass of manganese ore raw material and 13 parts by mass of reducing agent to obtain a mixture. Then add the mixture into the electric furnace and distribute it evenly around the three-phase electrodes. At the same time, the material surface in the central area of ​​the three-phase electrodes where the reaction is intense is 300 mm higher than the surrounding area. Control the working position of the three-phase electrodes to be 1600 mm away from the tapping hole. Control the reaction temperature at 1450℃. Control the electrode current of the electric furnace to 140 kA, the secondary voltage to 160 V, and the power factor to 0.85. Smelt the mixture to obtain medium carbon ferromanganese.

[0024] Testing revealed that the medium-carbon ferromanganese product prepared using the formula in this embodiment met the following weight percentage requirements: Mn 78%, C 1.6%, P 0.03%, with the remainder being iron and unavoidable impurities. The chemical composition of the slag obtained after smelting met the following weight percentage requirements: Mn 9%, SiO2 24%, CaO 26%, MgO 5%, Al2O3 9%, with the remainder being impurities, and the basicity being 1.3. The power consumption for actual heavy smelting was reduced to 2324 kWh / t, and the manganese recovery rate reached 93.38%.

[0025] Example 4 A process for preparing medium-carbon ferromanganese includes the following steps: (1) Mix 48 parts by weight of South African carbonate powder, 18 parts by weight of Gabonese ore, 17 parts by weight of Australian ore and 6 parts by weight of coke powder to obtain a mixture. Add the mixture to a sintering machine and sinter under the ignition of ferroalloy gas. Control the sintering temperature at 1100℃ and the sintering time at 2h. After cooling, crush to 20mm to obtain sintered ore. (2) Add 7 parts by weight of Gabonite, 6 parts by weight of Australian ore, 4 parts by weight of South African semi-carbonate ore and 12 parts by weight of South African iron ore into a drying kiln, use the heat generated by the combustion of coal gas in the electric arc furnace to heat and dry the material, control the drying temperature to 200℃, so that the moisture content of the dried lump ore is ≤1%, and obtain the dried lump ore. (3) The coke is screened to obtain coke with optimized particle size, which is used as a reducing agent. The particle size distribution of the coke is as follows by mass percentage: >30mm accounts for 12%, 20-30mm accounts for 54%, 10-20mm accounts for 30%, 5-10mm accounts for 2%, and <5mm accounts for 2%. (4) Mix the sintered ore and the dried lump ore at a mass ratio of 1.5:1 to obtain manganese ore raw material; (5) Mix 74 parts by mass of manganese ore raw material and 14 parts by mass of reducing agent to obtain a mixture. Then add the mixture into the electric furnace and distribute it evenly around the three-phase electrodes. At the same time, the material surface in the central area of ​​the three-phase electrodes where the reaction is intense is 300 mm higher than the surrounding area. Control the working position of the three-phase electrodes to be 1700 mm away from the tapping port. Control the reaction temperature at 1450℃. Control the electrode current of the electric furnace to 140 kA, the secondary voltage to 170 V, and the power factor to 0.85. Smelt the mixture to obtain medium carbon ferromanganese.

[0026] Testing revealed that the medium-carbon ferromanganese product prepared using the formula in this embodiment met the following weight percentage requirements: Mn 78%, C 1.9%, P 0.03%, with the remainder being iron and unavoidable impurities. The chemical composition of the slag obtained after smelting met the following weight percentage requirements: Mn 10%, SiO2 24%, CaO 28%, MgO 6%, Al2O3 10%, with the remainder being impurities, and the basicity being 1.3. The actual remelting power consumption was reduced to 2317 kWh / t, and the manganese recovery rate reached 93.96%.

[0027] Example 5 A process for preparing medium-carbon ferromanganese includes the following steps: (1) Mix 50 parts by weight of South African carbonate powder, 20 parts by weight of Gabonese ore, 20 parts by weight of Australian ore and 7 parts by weight of coke powder to obtain a mixture. Add the mixture to a sintering machine and sinter under the ignition of ferroalloy gas. Control the sintering temperature at 1150℃ and the sintering time at 3h. After cooling, crush to 25mm to obtain sintered ore. (2) Add 8 parts by weight of Gabonite, 7 parts by weight of Australian ore, 5 parts by weight of South African semi-carbonate ore and 12 parts by weight of South African iron ore into a drying kiln, use the heat generated by the combustion of coal gas in the electric arc furnace to heat and dry the material, control the drying temperature to 300℃, so that the moisture content of the dried lump ore is ≤1%, and obtain the dried lump ore. (3) The coke is screened to obtain coke with optimized particle size, which is used as a reducing agent. The particle size distribution of the coke is as follows by mass percentage: >30mm accounts for 15%, 20-30mm accounts for 55%, 10-20mm accounts for 26%, 5-10mm accounts for 3%, and <5mm accounts for 1%. (4) Mix the sintered ore and the dried lump ore at a mass ratio of 2:1 to obtain manganese ore raw material; (5) Mix 75 parts by mass of manganese ore raw material and 15 parts by mass of reducing agent to obtain a mixture. Then add the mixture into the electric furnace and distribute it evenly around the three-phase electrodes. At the same time, the material surface in the central area of ​​the three-phase electrodes where the reaction is intense is 400 mm higher than the surrounding area. Control the working position of the three-phase electrodes to be 1800 mm away from the tapping port. Control the reaction temperature at 1500℃. Control the electrode current of the electric furnace to 150 kA, the secondary voltage to 180 V, and the power factor to 0.86. Smelt the mixture to obtain medium carbon ferromanganese.

[0028] Testing revealed that the medium-carbon ferromanganese product prepared using the formula in this embodiment met the following weight percentage requirements: Mn 80%, C 2.6%, P 0.03%, with the remainder being iron and unavoidable impurities. The chemical composition of the slag obtained after smelting met the following weight percentage requirements: Mn 11%, SiO2 27%, CaO 34%, MgO 6%, Al2O3 13%, with the remainder being impurities, and the basicity being 1.4. The power consumption for actual heavy smelting was reduced to 2306 kWh / t, and the manganese recovery rate reached 93.81%.

[0029] Example 6 A process for preparing medium-carbon ferromanganese includes the following steps: (1) Mix 52 parts by weight of South African carbonate powder, 20 parts by weight of Gabonese ore, 22 parts by weight of Australian ore and 7 parts by weight of coke powder to obtain a mixture. Add the mixture to a sintering machine and sinter under the ignition of ferroalloy gas. Control the sintering temperature at 1200℃ and the sintering time at 3h. After cooling, crush to 35mm to obtain sintered ore. (2) Add 8 parts by weight of Gabonite, 9 parts by weight of Australian ore, 5 parts by weight of South African semi-carbonate ore and 13 parts by weight of South African iron ore into a drying kiln, use the heat generated by the combustion of coal gas in the electric arc furnace to heat and dry the material, control the drying temperature to 300℃, so that the moisture content of the dried lump ore is ≤1%, and obtain the dried lump ore. (3) The coke is screened to obtain coke with optimized particle size, which is used as a reducing agent. The particle size distribution of the coke is as follows by mass percentage: >30mm accounts for 16%, 20-30mm accounts for 50%, 10-20mm accounts for 30%, 5-10mm accounts for 2%, and <5mm accounts for 2%. (4) Mix the sintered ore and the dried lump ore at a mass ratio of 2:1 to obtain manganese ore raw material; (5) Mix 76 parts by mass of manganese ore raw material and 16 parts by mass of reducing agent to obtain a mixture. Then add the mixture into the electric furnace and distribute it evenly around the three-phase electrodes. At the same time, the material surface in the central area of ​​the three-phase electrodes where the reaction is intense is 400 mm higher than the surrounding area. Control the working position of the three-phase electrodes to be 1800 mm away from the tapping hole. Control the reaction temperature at 1500℃. Control the electrode current of the electric furnace within the range of 150 kA. Control the secondary voltage at 190 V. Control the power factor at 0.86. Smelt the mixture to obtain medium carbon ferromanganese.

[0030] Testing revealed that the medium-carbon ferromanganese product prepared using the formula in this embodiment met the following weight percentage requirements: Mn 82%, C 3.0%, P 0.05%, with the remainder being iron and unavoidable impurities. The chemical composition of the slag obtained after smelting met the following weight percentage requirements: Mn 12%, SiO2 28%, CaO 33%, MgO 7%, Al2O3 14%, with the remainder being impurities, and the basicity being 1.5. The power consumption for actual heavy smelting was reduced to 2343 kWh / t, and the manganese recovery rate reached 94.29%.

[0031] Example 7 A process for preparing medium-carbon ferromanganese includes the following steps: (1) Mix 58 parts by weight of South African carbonate powder, 28 parts by weight of Gabonese ore, 26 parts by weight of Australian ore and 7 parts by weight of coke powder to obtain a mixture. Add the mixture to a sintering machine and sinter under the ignition of ferroalloy gas. Control the sintering temperature at 1200℃ and the sintering time at 3h. After cooling, crush to 45mm to obtain sintered ore. (2) Add 9 parts by weight of Gabonite, 8 parts by weight of Australian ore, 6 parts by weight of South African semi-carbonate ore and 14 parts by weight of South African iron ore into a drying kiln, use the heat generated by the combustion of coal gas in the electric arc furnace to heat and dry the material, control the drying temperature to 300℃, so that the moisture content of the dried lump ore is ≤1%, and obtain the dried lump ore. (3) The coke is screened to obtain coke with optimized particle size, which is used as a reducing agent. The particle size distribution of the coke is as follows by mass percentage: >30mm accounts for 10%, 20-30mm accounts for 55%, 10-20mm accounts for 28%, 5-10mm accounts for 4%, and <5mm accounts for 3%. (4) Mix the sintered ore and the dried lump ore at a mass ratio of 2:1 to obtain manganese ore raw material; (5) Mix 78 parts by mass of manganese ore raw material and 17 parts by mass of reducing agent to obtain a mixture. Then add the mixture into the electric furnace and distribute it evenly around the three-phase electrodes. At the same time, the material surface in the central area of ​​the three-phase electrodes where the reaction is intense is 500 mm higher than the surrounding area. Control the working position of the three-phase electrodes to be 1900 mm away from the tapping hole. Control the reaction temperature at 1550℃. Control the electrode current of the electric furnace within the range of 160 kA. Control the secondary voltage at 200 V. Control the power factor at 0.86. Smelt the mixture to obtain medium carbon ferromanganese.

[0032] Testing revealed that the medium-carbon ferromanganese product prepared using the formula in this embodiment met the following weight percentage requirements: Mn 84%, C 3.6%, P 0.06%, with the remainder being iron and unavoidable impurities. The chemical composition of the slag obtained after smelting met the following weight percentage requirements: Mn 12%, SiO2 30%, CaO 37%, MgO 8%, Al2O3 16%, with the remainder being impurities, and the basicity being 1.6. The power consumption for actual heavy smelting was reduced to 2265 kWh / t, and the manganese recovery rate reached 94.28%.

[0033] Comparative Example 1 The main difference between this comparative example and Example 7 is that sintered ore and dried lump ore are mixed at a mass ratio of 1:1 to obtain manganese ore raw material.

[0034] Testing revealed that the medium-carbon ferromanganese product prepared using this comparative formula met the following weight percentage requirements: Mn 80%, C 3.2%, P 0.05%, with the remainder being iron and unavoidable impurities. The chemical composition of the slag obtained after smelting met the following weight percentage requirements: Mn 18%, SiO2 29%, CaO 35%, MgO 7%, Al2O3 15%, with the remainder being impurities, and the basicity being 1.4. The actual power consumption for heavy smelting was 2550 kWh / t, and the manganese recovery rate was 89.24%.

[0035] Comparative Example 2 The main difference between this comparative example and Example 7 is that coke is used instead of the coke with optimized particle size.

[0036] Testing revealed that the medium-carbon ferromanganese product prepared using this comparative formula met the following weight percentage requirements: Mn 79%, C 3.8%, P 0.05%, with the remainder being iron and unavoidable impurities. The chemical composition of the slag obtained after smelting met the following weight percentage requirements: Mn 20%, SiO2 30%, CaO 36%, MgO 7%, Al2O3 16%, with the remainder being impurities, and the basicity being 1.3. The actual power consumption for heavy smelting was 2661 kWh / t, and the manganese recovery rate was 88.03%.

[0037] Comparative Example 3 The main difference between this comparative example and Example 7 is that the working position of the three-phase electrodes is controlled at 1200mm from the horizontal position of the iron outlet.

[0038] Testing revealed that the medium-carbon ferromanganese product prepared using this comparative formula met the following weight percentage requirements: Mn 77%, C 2.8%, P 0.04%, with the remainder being iron and unavoidable impurities. The chemical composition of the slag obtained after smelting met the following weight percentage requirements: Mn 17%, SiO2 28%, CaO 33%, MgO 6%, Al2O3 14%, with the remainder being impurities, and the basicity being 1.3. The actual power consumption for heavy smelting was 2480 kWh / t, and the manganese recovery rate was 89.94%.

[0039] Comparative Example 4 The main difference between this comparative example and Example 7 is that the reaction temperature in step (5) is controlled at 1650°C.

[0040] Testing revealed that the medium-carbon ferromanganese product prepared using this comparative formula met the following weight percentage requirements: Mn 82%, C 2.0%, P 0.06%, with the remainder being iron and unavoidable impurities. The chemical composition of the slag obtained after smelting met the following weight percentage requirements: Mn 10%, SiO2 31%, CaO 38%, MgO 8%, Al2O3 17%, with the remainder being impurities, and the basicity being 1.5. The actual power consumption for heavy smelting was 2550 kWh / t, and the manganese recovery rate was 89.51%.

[0041] The comparison shows that in Comparative Example 1, the decrease in the proportion of sinter and the imbalance of the basicity of the furnace charge led to poor slag fluidity and incomplete reaction, resulting in an increased manganese content in the slag, higher smelting power consumption, and a decreased manganese recovery rate. In Comparative Example 2, the use of unscreened, mixed-size coke instead of optimized coke severely affected the permeability of the charge column and the kinetics of the reduction reaction, resulting in extremely low reduction efficiency and incomplete reduction. Therefore, it had the highest manganese content in the slag, the highest smelting power consumption, and the most significant decrease in manganese recovery rate. In Comparative Example 3, due to the decrease in the proportion of sintered ore and the imbalance of the basicity of the furnace charge, the slag fluidity of the slag decreased, leading to incomplete reaction and thus an increased manganese content in the slag, higher smelting power consumption, and a more significant decrease in manganese recovery rate. The electrode working position being too close to the tapping hole leads to an overly concentrated reaction zone, resulting in low thermal efficiency and unstable furnace conditions. Consequently, the manganese content in the slag increases, smelting power consumption rises, and manganese recovery rate decreases. In Comparative Example 4, the excessively high reaction temperature exacerbates the volatilization loss of manganese. Furthermore, since phosphorus reduction is a strongly endothermic reaction, high temperatures significantly promote a shift in thermodynamic equilibrium to the right, causing more phosphorus to be reduced and enter the medium-carbon ferromanganese from the raw materials. This results in a higher phosphorus content in the medium-carbon ferromanganese, which is detrimental to its quality. Therefore, smelting power consumption increases, and manganese recovery rate decreases.

[0042] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0043] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

[0044] Those skilled in the art should understand that the above descriptions are merely several specific embodiments of the present invention, and not all embodiments. It should be noted that many modifications and improvements can be made by those skilled in the art, and all modifications or improvements not exceeding the scope of the claims should be considered within the protection scope of the present invention.

Claims

1. A medium-carbon ferromanganese formulation, characterized in that, by mass, including: 70-80 parts of manganese ore raw material, 12-18 parts of reducing agent; The manganese ore raw material is mixed by sintered ore and dried lump ore in a mass ratio of 1.5-2:1; The reducing agent is coke; The medium-carbon ferromanganese product prepared by the formula meets: Mn 75-85%, C 1.0-4.0%, P 0.02-0.06%, and the balance is iron and inevitable impurities, by weight percentage.

2. Medium carbon ferromanganese formulation according to claim 1, characterized in that, The preparation raw material of the sintered ore includes, by mass parts: 40-60 parts of South African carbon powder, 10-30 parts of Gabon ore, 10-30 parts of Australian ore, and 5-8 parts of coke powder.

3. The medium-carbon ferromanganese formulation of claim 1, wherein, The chemical composition of the sintered ore meets: Mn 43-46%, Fe 7-20%, SiO2 5-10%, P 0.02-0.05%, CaO 5-15%, MgO 1-4%, Al2O3 0.5-2.5%, and the balance is impurities, by weight percentage, and the basicity is between 1.0-2.

0.

4. The medium-carbon ferromanganese formulation of claim 1, wherein, The dried lump ore is composed of the following mass parts of lump ore: 5-10 parts of Gabon ore, 5-10 parts of Australian ore, 3-6 parts of South African semi-carbonate ore, and 10-15 parts of South African medium iron ore.

5. The medium-carbon ferromanganese formulation of claim 1, wherein, The particle size distribution of the reducing agent coke is: 10-20% of >30mm, 50-60% of 20-30mm, 25-30% of 10-20mm, 2-5% of 5-10mm, and 1-3% of <5mm, by mass percentage.

6. A process for the preparation of the medium carbon ferromanganese formulation as claimed in claims 1-5, characterized in that, The method comprises the following steps: Step one: mix the South African carbon powder, Gabon ore, Australian ore, and coke powder to obtain a mixture, and add the mixture into a sintering machine to sinter under the ignition of the coal gas of the electric arc furnace, control the sintering temperature to be 1100-1200℃, and control the sintering time to be 2-3h, and crush to 5-50mm after cooling to obtain the sintered ore; Step two: add the Gabon ore, Australian ore, South African semi-carbonate ore, and South African medium iron ore into a drying kiln, and use the heat generated by the combustion of the coal gas of the electric arc furnace to heat and dry the materials, control the drying temperature to be 200-300℃, and make the moisture of the dried lump ore ≤1% to obtain the dried lump ore; Step three: screen the coke to obtain the coke with optimized particle size as the reducing agent; Step four: mix the sintered ore and the dried lump ore in a mass ratio of 1.5-2:1 to obtain the manganese ore raw material; Step five: mix the manganese ore raw material and the reducing agent to obtain a mixture, and then add the mixture into an electric furnace to smelt to obtain the medium-carbon ferromanganese.

7. The process for the preparation of medium-carbon ferromanganese formulation as claimed in claim 6, wherein, In the step five, the mixture entering the electric furnace is uniformly distributed around the three-phase electrode, and the material surface of the center area of the three-phase electrode with violent reaction is higher than the surrounding area by 300-500mm.

8. The process for the preparation of medium carbon ferromanganese formulation as claimed in claim 6 wherein, In the step five, the working position of the three-phase electrode is controlled to be at a horizontal position of 1500-2000mm from the tapping hole, and the reaction temperature is controlled to be 1450-1550℃.

9. The process for preparing medium-carbon ferromanganese formulation according to claim 6, characterized in that, In the step five, the electrode current of the electric furnace is controlled to be in the range of 130-160kA, the secondary voltage is controlled to be in the range of 150-210V, and the power factor is controlled to be in the range of 0.85-0.

86.

10. The process for preparing medium-carbon ferromanganese formulation as claimed in claim 6 wherein, The chemical composition of the slag obtained after smelting in the fifth step satisfies, in terms of percentage by weight: Mn 8-14%, SiO2 22-32%, CaO 25-40%, MgO 4-8%, Al2O3 8-18%, and the rest is impurities, and the basicity is between 1.2-1.6.