A medium-carbon manganese-iron formulation and its preparation process

Abstract

This invention discloses a medium-carbon ferromanganese formulation and its preparation process, belonging to the field of metallurgical technology. The preparation process includes the following steps: mixing South African carbonate powder, Gabonese ore, Australian ore, and coke powder to obtain a mixture; adding the mixture to a sintering machine and sintering it under the ignition of submerged arc furnace gas to obtain sintered ore; adding Gabonese ore, Australian ore, South African semi-carbonate ore, and South African ferromanganese ore to a drying kiln and using the heat generated by the combustion of submerged arc furnace gas to dry the materials to obtain dried lump ore; screening the coke to obtain coke with optimized particle size, which is used as a reducing agent; mixing the sintered ore with the dried lump ore to obtain manganese ore raw material; mixing the manganese ore raw material and the reducing agent to obtain a mixture; and then adding the mixture to an electric furnace for smelting to obtain medium-carbon ferromanganese. The medium-carbon ferromanganese obtained by this formulation and preparation process has stable composition, high manganese recovery rate, and low smelting power consumption.

Description

Technical Field

[0001] This invention belongs to the field of metallurgical technology, and more specifically, relates to a medium-carbon ferromanganese formula and its preparation process. Background Technology

[0002] Medium-carbon ferromanganese is an important alloying raw material in the steel industry. Its core process involves reducing manganese oxides from manganese ore and combining them with iron to form an alloy with a suitable carbon content. Currently, the mainstream smelting processes include the blast furnace method and the electric furnace method. The blast furnace method, due to the large amount of coke used in the smelting process, results in a high phosphorus content in the product, which restricts the control of subsequent steelmaking varieties and costs. The electric furnace method also suffers from high power consumption and low manganese recovery rate, limiting its economic viability. Therefore, avoiding this phenomenon is key to solving the problem. For example, Chinese invention patent CN106367591B discloses a method for preparing low-phosphorus medium-carbon ferromanganese by molten salt decarburization and dephosphorization of high-carbon ferromanganese. This invention uses molten salt to decarburize solid high-carbon ferromanganese at low temperatures and with high efficiency. It can also solve the problem of dephosphorization and decarburization of non-standard high-phosphorus high-carbon ferromanganese obtained from high-phosphorus manganese ore smelting. However, the problem of high power consumption in smelting remains to be solved. Summary of the Invention

[0003] Technical problems to be solved

[0004] To address the shortcomings of existing technologies, this invention provides a medium-carbon ferromanganese formulation and its preparation process that features stable composition, high manganese recovery rate, and low smelting power consumption.

[0005] Technical solution

[0006] To solve the above problems, the technical solution adopted by the present invention is as follows:

[0007] A medium-carbon ferromanganese formulation, by weight, comprises: 70-80 parts of manganese ore raw material and 12-18 parts of reducing agent;

[0008] The manganese ore raw material is a mixture of sintered ore and dried lump ore in a mass ratio of 1.5-2:1;

[0009] The reducing agent is coke;

[0010] The medium-carbon ferromanganese product prepared using this formula meets the following weight percentages: Mn 75-85%, C 1.0-4.0%, P 0.02-0.06%, with the balance being iron and unavoidable impurities.

[0011] Furthermore, the raw materials for preparing the sintered ore, by weight, include: 40-60 parts of South African carbonate powder, 10-30 parts of Gabonese ore, 10-30 parts of Australian ore, and 5-8 parts of coke powder.

[0012] Furthermore, the chemical composition of the sintered ore, by weight percentage, satisfies the following: 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%, with the remainder being impurities, and the basicity is between 1.0 and 2.0.

[0013] Furthermore, the dried lump ore consists of the following parts by weight: 5-10 parts Gabonese ore, 5-10 parts Australian ore, 3-6 parts South African semi-carbonate ore, and 10-15 parts South African mesocarpy ore.

[0014] Furthermore, the particle size distribution of the reducing agent coke, by mass percentage, is as follows: >30mm accounts for 10-20%, 20-30mm accounts for 50-60%, 10-20mm accounts for 25-30%, 5-10mm accounts for 2-5%, and <5mm accounts for 1-3%.

[0015] Furthermore, a preparation process for a medium-carbon ferromanganese formulation includes the following steps:

[0016] Step 1: Mix South African carbonate powder, Gabonese ore, Australian ore, and coke powder to obtain a mixture. Add the mixture to a sintering machine and sinter it under the ignition of coal gas in a submerged arc furnace. Control the sintering temperature at 1100-1200℃ and the sintering time at 2-3 hours. After cooling, crush it to 5-50mm to obtain sintered ore.

[0017] Step 2: Add Gabonese ore, Australian ore, South African semi-carbonate ore, and South African iron ore into the drying kiln. Use the heat generated by the combustion of coal gas in the electric arc furnace to heat and dry the materials. Control the drying temperature at 200-300℃ so that the moisture content of the dried lump ore is ≤1%, and obtain the dried lump ore.

[0018] Step 3: Screen the coke to obtain coke with optimized particle size, which will be used as a reducing agent;

[0019] Step 4: Mix the sintered ore and dried lump ore at a mass ratio of 1.5-2:1 to obtain manganese ore raw material;

[0020] Step 5: Mix the manganese ore raw material and reducing agent to obtain a mixture, and then add the mixture to an electric furnace for smelting to obtain medium carbon ferromanganese.

[0021] Furthermore, in step five, when the mixed material enters the electric furnace, it is evenly distributed around the three-phase electrodes, and the material surface in the central area of ​​the three-phase electrodes, where the reaction is intense, is 300-500 mm higher than the surrounding area.

[0022] Furthermore, in step five, the working position of the three-phase electrodes is controlled at 1500-2000 mm from the horizontal position of the iron outlet, and the reaction temperature is controlled at 1450-1550℃.

[0023] 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.

[0024] 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.

[0025] Beneficial technical effects

[0026] (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.

[0027] (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.

[0028] (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

[0029] 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.

[0030] To better understand the above technical solutions, the following will provide a detailed explanation of the technical solutions in conjunction with specific embodiments.

[0031] Example 1

[0032] A process for preparing medium-carbon ferromanganese includes the following steps:

[0033] (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.

[0034] (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.

[0035] (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%.

[0036] (4) Mix the sintered ore and the dried lump ore at a mass ratio of 1.5:1 to obtain manganese ore raw material;

[0037] (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.

[0038] 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%.

[0039] Example 2

[0040] A process for preparing medium-carbon ferromanganese includes the following steps:

[0041] (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.

[0042] (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.

[0043] (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%.

[0044] (4) Mix the sintered ore and the dried lump ore at a mass ratio of 2:1 to obtain manganese ore raw material;

[0045] (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.

[0046] 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%.

[0047] Example 3

[0048] A process for preparing medium-carbon ferromanganese includes the following steps:

[0049] (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.

[0050] (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.

[0051] (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%.

[0052] (4) Mix the sintered ore and the dried lump ore at a mass ratio of 1.5:1 to obtain manganese ore raw material;

[0053] (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.

[0054] 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%.

[0055] Example 4

[0056] A process for preparing medium-carbon ferromanganese includes the following steps:

[0057] (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.

[0058] (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.

[0059] (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%.

[0060] (4) Mix the sintered ore and the dried lump ore at a mass ratio of 1.5:1 to obtain manganese ore raw material;

[0061] (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.

[0062] 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%.

[0063] Example 5

[0064] A process for preparing medium-carbon ferromanganese includes the following steps:

[0065] (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.

[0066] (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.

[0067] (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%.

[0068] (4) Mix the sintered ore and the dried lump ore at a mass ratio of 2:1 to obtain manganese ore raw material;

[0069] (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.

[0070] 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%.

[0071] Example 6

[0072] A process for preparing medium-carbon ferromanganese includes the following steps:

[0073] (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.

[0074] (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.

[0075] (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%.

[0076] (4) Mix the sintered ore and the dried lump ore at a mass ratio of 2:1 to obtain manganese ore raw material;

[0077] (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.

[0078] 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%.

[0079] Example 7

[0080] A process for preparing medium-carbon ferromanganese includes the following steps:

[0081] (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.

[0082] (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.

[0083] (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%.

[0084] (4) Mix the sintered ore and the dried lump ore at a mass ratio of 2:1 to obtain manganese ore raw material;

[0085] (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.

[0086] 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%.

[0087] Comparative Example 1

[0088] 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.

[0089] 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%.

[0090] Comparative Example 2

[0091] The main difference between this comparative example and Example 7 is that coke is used instead of the coke with optimized particle size.

[0092] 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%.

[0093] Comparative Example 3

[0094] 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.

[0095] 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%.

[0096] Comparative Example 4

[0097] The main difference between this comparative example and Example 7 is that the reaction temperature in step (5) is controlled at 1650°C.

[0098] 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%.

[0099] 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.

[0100] 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.

[0101] 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.

[0102] 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, characterized in that, Manganese ore raw material, reducing agent are mixed to obtain mixed material, then the mixed material is added into an electric furnace for smelting to obtain medium-carbon ferromanganese, which comprises, by mass fraction: 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 at a mass ratio of 1.5-2:1; The reducing agent is coke; The medium-carbon ferromanganese satisfies, by weight percentage: Mn 75-85%, C 1.0-4.0%, P 0.02-0.06%, and the balance is iron and inevitable impurities; The preparation raw material of the sintered ore comprises, by mass fraction: 40-60 parts of South African carbon powder, 10-30 parts of Gabon ore, 10-30 parts of Australia ore, and 5-8 parts of coke powder; The dried lump ore is composed of lump ores in the following mass fractions: 5-10 parts of Gabon ore, 5-10 parts of Australia ore, 3-6 parts of South African semi-carbonate ore, and 10-15 parts of South African medium-iron ore; The particle size distribution of the reducing agent coke is as follows, by mass percentage: 10-20% of >30mm, 50-60% of 20-30mm, 25-30% of 10-20mm, 2-5% of 5-10mm, and 1-3% of <5mm; The mixed material is uniformly distributed around the three-phase electrode when entering the electric furnace, and the material surface of the center area of the three-phase electrode with violent reaction is 300-500mm higher than the surrounding area; The working position of the three-phase electrode is controlled to be at a horizontal position of 1500-2000mm from the tapping hole, the reaction temperature is controlled at 1450-1550℃, and the basicity of the slag obtained after smelting is between 1.2-1.

6.

2. Medium-carbon ferromanganese according to claim 1, characterized in that, The chemical composition of the sintered ore satisfies, by weight percentage: 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, and the basicity is between 1.0-2.

0.

3. A process for the production of medium-carbon ferromanganese as claimed in any one of claims 1-2, characterized in that, The method comprises the following steps: Step one: mixing South African carbon powder, Gabon ore, Australia ore, and coke powder to obtain mixed material, and adding the mixed material into a sintering machine to sinter under the ignition of the coal gas of an electric furnace, controlling the sintering temperature to be 1100-1200℃, and the sintering time to be 2-3h, and crushing to 5-50mm after cooling to obtain sintered ore; Step two: adding Gabon ore, Australia ore, South African semi-carbonate ore, and South African medium-iron ore into a drying kiln, and using the heat generated by the combustion of the coal gas of the electric furnace to heat and dry the material, controlling the drying temperature to be 200-300℃, so that the moisture of the dried lump ore is ≤1%, and obtaining dried lump ore; Step three: screening the coke to obtain particle size optimized coke as reducing agent; Step four: mixing the sintered ore and the dried lump ore at a mass ratio of 1.5-2:1 to obtain manganese ore raw material; Step five: mixing the manganese ore raw material and the reducing agent to obtain mixed material, and then adding the mixed material into an electric furnace for smelting to obtain medium-carbon ferromanganese.

4. The process for preparing medium-carbon ferromanganese according to claim 3, characterized in that, The electrode current control range of the electric furnace in the fifth step is 130-160 kA, the secondary voltage control is 150-210 V, and the power factor control is 0.85-0.

86.

5. The process for preparing medium-carbon ferromanganese according to claim 3, characterized in that, 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.