A kind of aluminum slag type smelting process with low slag ratio for manganese silicon alloy

Abstract

The present invention discloses a low slag ratio aluminum slag type smelting process for manganese silicon alloy, including batching, electrode adjustment, smelting control, slag type optimization adjustment and regular furnace washing. The present invention can improve the stability of the thermal system of the ore-fired furnace, the molten pool in the furnace is highly active, the thermal system recovers quickly and the recovery period is short during the process of restoring the furnace condition after the furnace is shut down for maintenance, and the problems of long furnace condition recovery period and substandard alloy quality are solved. After the implementation of the present invention, the slag-iron ratio is reduced from 0.85 to within 0.70, the smelting power consumption is reduced by more than 150kwh / t, and the manganese element recovery rate is increased by more than 2%.

Description

Technical Field

[0001] The invention belongs to the technical field of ferroalloy production, and in particular relates to a low-slag-ratio aluminum slag type smelting process for manganese-silicon alloy. Background Art

[0002] Manganese silicon alloy is an alloy composed of manganese, silicon, iron, a small amount of carbon and other elements. It is a ferroalloy with a wide range of uses and a large output. Manganese silicon alloy is a commonly used composite deoxidizer in steelmaking, and a reducing agent in the production of medium and low carbon ferromanganese and the production of metallic manganese by electrosilicon thermal method.

[0003] Silicon manganese smelting mainly includes calcium slag type (CaO-MgO-SiO2) and aluminum slag type (Al2O3-CaO-MgO-SiO2). The industry basically uses calcium slag type smelting process as the main one. Hongdian Ferroalloy has adopted calcium slag type smelting process since it started smelting silicon manganese. Under this process, iron and slag are relatively smooth, alloy quality is stable, and furnace condition is easy to control. However, there are also very prominent problems. The calcium slag type is mainly a high-alkalinity and large-slag process. First, it is easy to cause erosion of the furnace body and furnace eye, and there is a risk of eye running and furnace penetration; second, the large amount of slag takes away a lot of heat, the thermal utilization rate is low, and the indicators are relatively poor; third, the thermal system stability is poor during the hot shutdown and recovery of the furnace condition, the heating time is relatively long, and there are many defective products during the recovery of the furnace condition.

[0004] Low slag ratio aluminum slag type is the comprehensive application of low slag ratio process and aluminum slag type technology. The two complement each other. When the slag ratio is lower than 0.75 times and the Al2O3 content in the slag reaches more than 18%, it is the low slag ratio aluminum slag type.

[0005] From the silicon manganese smelting principle and production practice, it can be known that for the production of 1t of manganese silicon alloy, the smelting power consumption is reduced by about 60-70kWh for every 10% reduction in slag volume. At the same time, as the slag volume decreases, the concentration of metal reactants increases, which is beneficial to the reduction of the alloy and improves the metal recovery rate.

[0006] The key to low slag ratio smelting is to reduce the amount of auxiliary materials by improving the silicon recovery rate, which mainly includes the following aspects: First, reasonably match the materials, increase the natural alkalinity and self-contained silicon dioxide content of the ingredients, and reduce the amount of auxiliary materials dolomite and silica, mainly the economic batching research of high silicon manganese ore and high alkalinity manganese ore; second, control the coke particle size and maintain the appropriate coke layer thickness in the furnace, which is not only a very important process requirement for manganese silicon alloy smelting, but also an important measure for low slag ratio operation. The sign of appropriate coke particle size and coke layer thickness is that on the one hand, it is necessary to ensure that the electrode working end is On the one hand, it is buried deep in the charge, but it cannot produce slag turning over or large-scale collapse of the charge. On the other hand, it provides sufficient reaction specific surface area for elements such as manganese and silicon, so that the reduction rate matches the melting rate of the material; thirdly, it reduces carbon discharge when out of the furnace, and reduces the corresponding carbon amount when mixing the materials. This is beneficial to stabilize the thickness of the coke layer in the furnace before and after the furnace is out of the furnace, as well as stabilize and increase the resistance of the charge during the smelting process; fourthly, when mixing the materials, the content of A1203 in the raw materials entering the furnace is appropriate; fifthly, the smelting time is appropriately extended to reduce heat loss, and the furnace temperature is further increased to make the elements such as manganese and silicon in the slag more fully reduced.

[0007] Under normal production processes, the silicon recovery rate is low under the calcium slag type process, the amount of auxiliary materials used is high, and the slag volume is too large. On the one hand, a lot of heat is taken away during the iron-making process, resulting in low thermal utilization rate; on the other hand, the excessive slag volume dilutes the concentration of beneficial elements, worsens the kinetics and thermodynamic conditions of alloy reduction, resulting in insufficient alloy reduction rate and stagnation of economic and technical indicators.

[0008] Under normal production conditions, the presence of calcium slag aggravates the scouring and circulation erosion of the furnace wall and furnace eye by the slag, resulting in a shortened service life of the furnace eye and furnace front, and there is a serious risk of leakage and iron leakage. Summary of the invention

[0009] The purpose of the present invention is to provide a manganese silicon alloy low slag ratio aluminum slag type smelting process to solve the problems of large slag volume, unstable thermal system, low thermal utilization rate, stagnant indicators, serious erosion of furnace body and furnace eye, long furnace condition recovery period and many defective products in the manganese silicon alloy calcium slag type smelting process.

[0010] In order to achieve the above object, the technical solution adopted by the present invention is:

[0011] A low-slag ratio aluminum slag type smelting process for manganese-silicon alloy comprises the following steps:

[0012] (1) Ingredients:

[0013] Including manganese ore ingredients and coke ingredients:

[0014] Manganese ore batching: control the furnace grade to be above 34%, silicon recovery rate to be 63%-65%, and Al2O3 content in comprehensive manganese ore to be controlled at 6%-7.5%; on the basis of matching the smelting process system, firstly, select manganese ore with high SiO2 content, increase the natural silicon dioxide content in the raw materials, reduce the amount of auxiliary materials, and lay the foundation for reducing the slag ratio; secondly, select manganese ore with high Al2O3 content, which is a prerequisite for achieving aluminum slag type, so choose high-quality manganese ore, that is, Australian ore or Brazilian manganese ore;

[0015] Coke ingredients: by weight percentage, 65%-80% of coke with a particle size of 25-40mm, 20%-35% of coke with a particle size of 10-30mm;

[0016] (2) Electrode adjustment:

[0017] The electrode displacement is controlled at 300-650mm, the electrode limit is at the middle-lower limit, and the pressure release increases by 20-30mm / day; the electrode limit is at the middle-upper limit, and the pressure release decreases by 20-30mm / day, stabilizing the electrode work, and the molten iron temperature in the ore-fired furnace increases from 1520℃-1530℃ to above 1540℃; smelting control includes electrode position adjustment and voltage use, and electrode position adjustment is achieved by electrode pressure release and displacement adjustment;

[0018] (3) Smelting control:

[0019] The gear position is controlled by 2±1 gears, high voltage operation, and the secondary voltage is increased by 5-10V; the secondary voltage is increased by 5-10V, which can improve the electrode work and the effect of iron and slag discharge from the furnace eye, ensuring the long-term stable and smooth operation of the furnace condition;

[0020] (4) Slag shape optimization and adjustment:

[0021] The manganese content in the slag is controlled at 4.5%-6%, the SiO2 content in the slag is controlled at 28%-32%, the slag basicity is controlled at 0.55-0.65, and the Al2O3 content in the slag is controlled at 18%-22%;

[0022] When the manganese content in the slag is greater than 6%, add coke or insert electrodes; reduce carbon according to the alloy silicon composition, insert electrodes to expand the molten pool and increase the activity of the molten pool

[0023] When the Al2O3 content in the slag is greater than 18% and the SiO2 content in the slag is greater than 32%, reduce the amount of silica;

[0024] When the Al2O3 content in the slag is greater than 18% and the SiO2 content in the slag is between 28% and 32%, reduce the amount of coke used;

[0025] (5) Clean the furnace regularly:

[0026] The furnace is cleaned every 10-15 days, with dolomite, limestone or calcium chloride, and each batch of materials is increased by 40-50kg. Regular furnace cleaning can prevent the operation of the furnace from shrinking under long-term low-calcium slag smelting, which will deteriorate the furnace condition and index regression.

[0027] In order to further realize the present invention, the manganese ore ingredients in step (1) include the following raw materials in weight percentage: 18%-22% high-quality manganese ore, 20%-25% high-aluminum Gabon manganese ore, 15%-18% South African semi-carbonic acid, 13%-15% South African high-iron, 10%-15% manganese-rich slag or Qinghai manganese ore, 10%-15% silicon-manganese dry slag, 6%-8% dust ash briquette and 1%-2% silicon slag. Silicon-manganese dry slag is an exothermic reaction in the process of participating in the smelting of manganese-silicon alloy, which can provide heat and silicon elements required by the alloy, greatly reduce the slag ratio, and promote the application of low slag ratio and aluminum slag type.

[0028] In order to further realize the present invention, the high-quality manganese ore in step (1) is Australian or Brazilian manganese ore.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] Aluminum slag is mainly composed of Al2O3, a high melting point compound that can increase the temperature of the slag in the furnace and promote the effective reduction of the metal. In the production of silicon-manganese alloy, the level of Al2O3 directly determines the performance and technical indicators of the slag.

[0031] When the Al2O3 content in the slag reaches more than 15%, the slag resistance increases significantly with the increase of Al2O3 content, and the slag viscosity increases with the increase of Al2O3 content at low temperature, and the slag viscosity is not much different at high temperature (>1500℃). The aluminum content in aluminum slag is generally 15-32%. During the batching process, the natural Al2O3 content is controlled at 6%-7.5%, and the Al2O3 in the slag is 18-22%. The aluminum slag type is used to promote the reduction of alloy silicon and reduce the slag ratio, thereby realizing the comprehensive application of low slag ratio aluminum slag type technology, thereby solving the problems existing in calcium slag type smelting, improving the stability of furnace conditions, realizing the long-term stable and smooth operation of the ore-fired furnace, continuously improving economic and technical indicators, and greatly reducing production costs.

[0032] The present invention can improve the stability of the thermal system of the ore-fired furnace, the molten pool in the furnace has high activity, the thermal system recovers quickly and the recovery period is short during the process of restoring the furnace condition after shutdown for maintenance, and the problems of long furnace condition recovery period and substandard alloy quality in the past are solved.

[0033] After the implementation of the present invention, the slag-iron ratio is reduced from 0.85 to within 0.70, the smelting power consumption is reduced by more than 150 kwh / t, and the manganese recovery rate is increased by more than 2%. DETAILED DESCRIPTION

[0034] The present invention will be further described below in conjunction with specific implementation modes.

[0035] A low-slag ratio aluminum slag type smelting process for manganese-silicon alloy comprises the following steps:

[0036] (1) Ingredients:

[0037] Including manganese ore ingredients and coke ingredients:

[0038] Manganese ore batching: control the furnace grade to be above 34%, silicon recovery rate to be 63%-65%, Al2O3 content in comprehensive manganese ore to be 6%-7.5%, including the following raw materials in weight percentage: high-quality manganese ore 18%-22%, high-aluminum Gabon manganese ore 20%-25%, South African semi-carbonate 15%-18%, South African high-iron 13%-15%, manganese-rich slag or Qinghai manganese ore 10%-15%, silicon-manganese dry slag 10%-15%, dust removal ash briquette 6%-8% and silicon slag 1%-2%, among which the high-quality manganese ore is Australian ore or Brazilian manganese ore;

[0039] Coke ingredients: by weight percentage, 65%-80% of coke with a particle size of 25-40mm, 20%-35% of coke with a particle size of 10-30mm;

[0040] (2) Electrode adjustment:

[0041] The electrode displacement is controlled at 300-650mm, the electrode limit is at the middle and lower limit, and the pressure release increases by 20-30mm / day; the electrode limit is at the middle and upper limit, and the pressure release decreases by 20-30mm / day, stabilizing the electrode work, and the molten iron temperature in the ore-fired furnace increases from 1520℃-1530℃ to above 1540℃;

[0042] (3) Smelting control:

[0043] The gear position is controlled by 2±1 gears, high voltage operation, and the secondary voltage increases by 5-10V;

[0044] (4) Slag shape optimization and adjustment:

[0045] The manganese content in the slag is controlled at 4.5%-6%, the SiO2 content in the slag is controlled at 28%-32%, the slag basicity is controlled at 0.55-0.65, and the Al2O3 content in the slag is controlled at 18%-22%;

[0046] When the manganese content in the slag is greater than 6%, add coke or insert electrodes;

[0047] When the Al2O3 content in the slag is greater than 18% and the SiO2 content in the slag is greater than 32%, reduce the amount of silica;

[0048] When the Al2O3 content in the slag is greater than 18% and the SiO2 content in the slag is between 28% and 32%, reduce the amount of coke used;

[0049] (5) Clean the furnace regularly:

[0050] Regular furnace cleaning is carried out every 10-15 days, using dolomite, limestone or calcium chloride to wash the furnace, and each batch of materials is increased by 40-50kg.

[0051] Embodiment 1:

[0052] A low-slag ratio aluminum slag type smelting process for manganese-silicon alloy comprises the following steps:

[0053] (1) Ingredients:

[0054] Including manganese ore ingredients and coke ingredients:

[0055] Manganese ore ingredients: including the following raw materials in weight percentage: Australian ore 18%, high-aluminum Gabon manganese ore 20%, South African semi-carbonate 15%, South African high-iron 14%, manganese-rich slag 15%, silicon-manganese dry slag 10%, dust removal ash briquette 6% and silicon slag 2%;

[0056] Coke ingredients: by weight percentage, 75 parts of coke with a particle size of 25-40 mm, 25 parts of coke with a particle size of 10-30 mm;

[0057] The carbon dosage is adjusted up or down by 10kg on the normal basis;

[0058] According to the ingredient calculation, the furnace grade is calculated to be 35.2%, the silicon recovery rate is 63%, the theoretical slag basicity is 0.58, and the SiO2 and Al2O3 content in the slag are 31.8% and 20.68%.

[0059] (2) Electrode adjustment:

[0060] The electrode displacement is controlled at 300-600mm, the electrode limit is at the middle-lower limit, and the pressure release increases by 20-30mm / day; the electrode limit is at the middle-upper limit, and the pressure release decreases by 20-30mm / day, stabilizing the electrode work, and the molten iron temperature in the ore-fired furnace increases from 1520℃-1530℃ to above 1540℃;

[0061] (3) Smelting control:

[0062] The gear position is controlled by 2±1 gears, high voltage operation, and the secondary voltage is increased by 5-10V, that is, from 215V to 220V;

[0063] (4) Slag shape optimization and adjustment:

[0064] The manganese content in the slag is controlled at 5%, the SiO2 content in the slag is controlled at 30%-31%, the slag basicity is controlled at 0.60-0.65, and the Al2O3 content in the slag is controlled at 20%-22%;

[0065] (5) Clean the furnace regularly:

[0066] Regular furnace cleaning is carried out every 10-15 days, using dolomite, limestone or calcium chloride to wash the furnace, and each batch of materials is increased by 40-50kg.

[0067] In this embodiment, the furnace condition is stable, the slag-iron ratio is 0.68, the average daily output is increased from about 140t to 142t, the smelting power consumption is reduced from 4200kwh / t to 4050kwh / t, the recovery rate is increased from 85.6% to 89%, and the alloy quality is increased from 88% to 98.5%. On the basis of stabilizing the furnace condition, the alloy quality and economic and technical indicators are improved.

[0068] Embodiment 2:

[0069] A low-slag ratio aluminum slag type smelting process for manganese-silicon alloy comprises the following steps:

[0070] (1) Ingredients:

[0071] Including manganese ore ingredients and coke ingredients:

[0072] Manganese ore ingredients: including the following raw materials in weight percentage: Australian ore 20%, high-aluminum Gabon manganese ore 21%, South African semi-carbonate 15%, South African high-iron 13%, manganese-rich slag 13%, silicon-manganese dry slag 10%, dust removal ash briquette 6% and silicon slag 2%;

[0073] Coke ingredients: by weight percentage, 75 parts of coke with a particle size of 25-40 mm, 25 parts of coke with a particle size of 10-30 mm;

[0074] The carbon dosage is adjusted up or down by 10kg on the normal basis;

[0075] According to the ingredient calculation, the furnace grade is calculated to be 35.6%, the silicon recovery rate is 65%, and the theoretical slag basicity is about 0.62 times, with SiO230.4% and Al2O321.2% in the slag.

[0076] (2) Electrode adjustment:

[0077] The electrode displacement is controlled at 300-650mm, the electrode limit is at the middle and lower limit, and the pressure release increases by 20-30mm / day; the electrode limit is at the middle and upper limit, and the pressure release decreases by 20-30mm / day, stabilizing the electrode work, and the molten iron temperature in the ore-fired furnace increases from 1520℃-1530℃ to above 1550℃;

[0078] (3) Smelting control:

[0079] The gear position is controlled by 2±1 gears, high voltage operation, and the secondary voltage is increased by 5-10V, that is, from 215V to 222V;

[0080] (4) Slag shape optimization and adjustment:

[0081] The manganese content in the slag is controlled at 4.5%, the SiO2 content in the slag is controlled at 28%-30%, the slag basicity is controlled at 0.55-0.62, and the Al2O3 content in the slag is controlled at 21%-22%;

[0082] (5) Clean the furnace regularly:

[0083] Regular furnace cleaning is carried out every 10-15 days, using dolomite, limestone or calcium chloride to wash the furnace, and each batch of materials is increased by 40-50kg.

[0084] In this embodiment, the furnace condition is stable, the slag-iron ratio is 0.65, the average daily output is increased from about 140t to 144t, the smelting power consumption is reduced from 4200kwh / t to 4000kwh / t, the recovery rate is increased from 85.6% to 90.4%, and the alloy quality is increased from 88% to 99.8%. On the basis of stabilizing the furnace condition, the alloy quality and economic and technical indicators are improved.

[0085] Embodiment 3:

[0086] A low-slag ratio aluminum slag type smelting process for manganese-silicon alloy comprises the following steps:

[0087] (1) Ingredients:

[0088] Including manganese ore ingredients and coke ingredients:

[0089] Manganese ore ingredients: including the following raw materials in weight percentage: Australian ore 18%, high-aluminum Gabon manganese ore 25%, South African semi-carbonate 15%, South African high-iron 15%, Qinghai manganese ore 10%, silicon manganese dry slag 10%, dust removal ash briquette 6% and silicon slag 1%;

[0090] Coke ingredients: by weight percentage, 65 parts of coke with a particle size of 25-40 mm, 35 parts of coke with a particle size of 10-30 mm;

[0091] The carbon dosage is adjusted up or down by 10kg on the normal basis;

[0092] According to the ingredient calculation, the furnace grade is calculated to be 34.8%, the silicon recovery rate is 63%, the theoretical slag basicity is 0.60, and the SiO2 and Al2O3 content in the slag are 29.8% and 21%.

[0093] (2) Electrode adjustment:

[0094] The electrode displacement is controlled at 300-600mm, the electrode limit is at the middle-lower limit, and the pressure release increases by 20-30mm / day; the electrode limit is at the middle-upper limit, and the pressure release decreases by 20-30mm / day, stabilizing the electrode work, and the molten iron temperature in the ore-fired furnace increases from 1520℃-1530℃ to above 1540℃;

[0095] (3) Smelting control:

[0096] The gear position is controlled by 2±1 gears, high voltage operation, and the secondary voltage is increased by 5-10V, that is, from 215V to 220V;

[0097] (4) Slag shape optimization and adjustment:

[0098] The manganese content in the slag is controlled at 5%, the SiO2 content in the slag is controlled at 30%-31%, the slag basicity is controlled at 0.60-0.65, and the Al2O3 content in the slag is controlled at 20%-22%;

[0099] (5) Clean the furnace regularly:

[0100] Regular furnace cleaning is carried out every 10-15 days, using dolomite, limestone or calcium chloride to wash the furnace, and each batch of materials is increased by 40-50kg.

[0101] In this embodiment, the furnace condition is stable, the slag-iron ratio is 0.67, the average daily output is increased from about 140t to 142.4t, the smelting power consumption is reduced from 4200kwh / t to 4010kwh / t, the recovery rate is increased from 85.6% to 89.76%, and the alloy quality is increased from 88% to 99.23%. On the basis of stabilizing the furnace condition, the alloy quality and economic and technical indicators are improved.

[0102] Embodiment 4:

[0103] A low-slag ratio aluminum slag type smelting process for manganese-silicon alloy comprises the following steps:

[0104] (1) Ingredients:

[0105] Including manganese ore ingredients and coke ingredients:

[0106] Manganese ore ingredients: including the following raw materials in weight percentage: Australian ore 22%, high-aluminum Gabon manganese ore 20%, South African semi-carbonate 15%, South African high-iron 13%, Qinghai manganese ore 10%, silicon manganese dry slag 10%, dust removal ash briquette 8% and silicon slag 2%;

[0107] Coke ingredients: by weight percentage, 80 parts of coke with a particle size of 25-40 mm, 20 parts of coke with a particle size of 10-30 mm;

[0108] The carbon dosage is adjusted up or down by 10kg on the normal basis;

[0109] According to the ingredient calculation, the furnace grade is calculated to be 35.0%, the silicon recovery rate is 63%, the theoretical slag basicity is 0.65, and the SiO2 and Al2O3 content in the slag are 31.2% and 20.8%.

[0110] (2) Electrode adjustment:

[0111] The electrode displacement is controlled at 300-600mm, the electrode limit is at the middle-lower limit, and the pressure release increases by 20-30mm / day; the electrode limit is at the middle-upper limit, and the pressure release decreases by 20-30mm / day, stabilizing the electrode work, and the molten iron temperature in the ore-fired furnace increases from 1520℃-1530℃ to above 1540℃;

[0112] (3) Smelting control:

[0113] The gear position is controlled by 2±1 gears, high voltage operation, and the secondary voltage is increased by 5-10V, that is, from 215V to 220V;

[0114] (4) Slag shape optimization and adjustment:

[0115] The manganese content in the slag is controlled at 5%, the SiO2 content in the slag is controlled at 30%-31%, the slag basicity is controlled at 0.60-0.65, and the Al2O3 content in the slag is controlled at 20%-22%;

[0116] (5) Clean the furnace regularly:

[0117] Regular furnace cleaning is carried out every 10-15 days, using dolomite, limestone or calcium chloride to wash the furnace, and each batch of materials is increased by 40-50kg.

[0118] In this embodiment, the furnace condition is stable, the slag-iron ratio is 0.68, the average daily output is increased from about 140t to 141t, the smelting power consumption is reduced from 4200kwh / t to 3950kwh / t, the recovery rate is increased from 85.6% to 90.2%, and the alloy quality is improved from 88% to 99%. On the basis of stabilizing the furnace condition, the alloy quality and economic and technical indicators are improved.

[0119] Embodiment 5:

[0120] A low-slag ratio aluminum slag type smelting process for manganese-silicon alloy comprises the following steps:

[0121] (1) Ingredients:

[0122] Including manganese ore ingredients and coke ingredients:

[0123] Manganese ore ingredients: including the following raw materials in weight percentage: Australian ore 18%, high-aluminum Gabon manganese ore 20%, South African semi-carbonate 15%, South African high-iron 13%, manganese-rich slag 10%, silicon-manganese dry slag 15%, dust removal ash briquette 6% and silicon slag 1%;

[0124] Coke ingredients: by weight percentage, 76 parts of coke with a particle size of 25-40 mm, 24 parts of coke with a particle size of 10-30 mm;

[0125] The carbon dosage is adjusted up or down by 10kg on the normal basis;

[0126] The ingredients were calculated and the furnace grade was 35.2%, the silicon recovery rate was 63%, the slag basicity was theoretically calculated to be 0.61, and the SiO2 and Al2O3 content in the slag was 30%, 20%.

[0127] (2) Electrode adjustment:

[0128] The electrode displacement is controlled at 300-600mm, the electrode limit is at the middle-lower limit, and the pressure release increases by 20-30mm / day; the electrode limit is at the middle-upper limit, and the pressure release decreases by 20-30mm / day, stabilizing the electrode work, and the molten iron temperature in the ore-fired furnace increases from 1520℃-1530℃ to above 1540℃;

[0129] (3) Smelting control:

[0130] The gear position is controlled by 2±1 gears, high voltage operation, and the secondary voltage is increased by 5-10V, that is, from 215V to 220V;

[0131] (4) Slag shape optimization and adjustment:

[0132] The manganese content in the slag is controlled at 5%, the SiO2 content in the slag is controlled at 30%-31%, the slag basicity is controlled at 0.60-0.65, and the Al2O3 content in the slag is controlled at 20%-22%;

[0133] (5) Clean the furnace regularly:

[0134] Regular furnace cleaning is carried out every 10-15 days, using dolomite, limestone or calcium chloride to wash the furnace, and each batch of materials is increased by 40-50kg.

[0135] In this embodiment, the furnace condition is stable, the slag-iron ratio is 0.69, the average daily output is increased from about 140t to 142.5t, the smelting power consumption is reduced from 4200kwh / t to 4030kwh / t, the recovery rate is increased from 85.6% to 90.4%, and the alloy quality is increased from 88% to 99.2%. On the basis of stabilizing the furnace condition, the alloy quality and economic and technical indicators are improved.

[0136] Embodiment 6:

[0137] A low-slag ratio aluminum slag type smelting process for manganese-silicon alloy comprises the following steps:

[0138] (1) Ingredients:

[0139] Including manganese ore ingredients and coke ingredients:

[0140] Manganese ore ingredients: including the following raw materials in weight percentage: Australian ore 18%, high-aluminum Gabon manganese ore 20%, South African semi-carbonate 18%, South African high-iron 13%, Qinghai manganese ore 10%, silicon-manganese dry slag 10%, dust removal ash briquette 8% and silicon slag 2%;

[0141] Coke ingredients: by weight percentage, 70 parts of coke with a particle size of 25-40 mm, 30 parts of coke with a particle size of 10-30 mm;

[0142] The carbon dosage is adjusted up or down by 10kg on the normal basis;

[0143] According to the ingredient calculation, the furnace grade is 35.8%, the silicon recovery rate is 63%, the theoretical slag basicity is 67, and the SiO2 content in the slag is 30.3%, and the Al2O3 content is 20.9%.

[0144] (2) Electrode adjustment:

[0145] The electrode displacement is controlled at 300-600mm, the electrode limit is at the middle-lower limit, and the pressure release increases by 20-30mm / day; the electrode limit is at the middle-upper limit, and the pressure release decreases by 20-30mm / day, stabilizing the electrode work, and the molten iron temperature in the ore-fired furnace increases from 1520℃-1530℃ to above 1540℃;

[0146] (3) Smelting control:

[0147] The gear position is controlled by 2±1 gears, high voltage operation, and the secondary voltage is increased by 5-10V, that is, from 215V to 220V;

[0148] (4) Slag shape optimization and adjustment:

[0149] The manganese content in the slag is controlled at 5%, the SiO2 content in the slag is controlled at 30%-31%, the slag basicity is controlled at 0.60-0.65, and the Al2O3 content in the slag is controlled at 20%-22%;

[0150] (5) Clean the furnace regularly:

[0151] Regular furnace cleaning is carried out every 10-15 days, using dolomite, limestone or calcium chloride to wash the furnace, and each batch of materials is increased by 40-50kg.

[0152] In this embodiment, the furnace condition is stable, the slag-iron ratio is 0.66, the average daily output is increased from about 140t to 143.1t, the smelting power consumption is reduced from 4200kwh / t to 4035.6kwh / t, the recovery rate is increased from 85.6% to 90.42%, and the alloy quality is increased from 88% to 99.8%. On the basis of stabilizing the furnace condition, the alloy quality and economic and technical indicators are improved.

Claims

1. A low slag ratio aluminum slag type smelting process for manganese silicon alloy, characterized in that: The steps include: (1) Ingredients: Including manganese ore ingredients and coke ingredients: Manganese ore batching: control the furnace grade to be above 34%, silicon recovery rate to be 63%-65%, and Al2O3 content in comprehensive manganese ore to be 6%-7.5%; manganese ore batching includes the following raw materials in weight percentage: high-quality manganese ore 18%-22%, high-aluminum Gabon manganese ore 20%-25%, South African semi-carbonate 15%-18%, South African high-iron 13%-15%, manganese-rich slag or Qinghai manganese ore 10%-15%, silicon-manganese dry slag 10%-15%, dust removal ash briquette 6%-8% and silicon slag 1%-2%; high-quality manganese ore uses Australian ore or Brazilian manganese ore; Coke ingredients: by weight percentage, 65%-80% of coke with a particle size of 25-40mm, 20%-35% of coke with a particle size of 10-30mm; (2) Electrode adjustment: The electrode displacement is controlled at 300-650mm, the electrode limit is at the middle and lower limit, and the pressure release increases by 20-30mm / day; the electrode limit is at the middle and upper limit, and the pressure release decreases by 20-30mm / day, stabilizing the electrode work, and the molten iron temperature in the ore-fired furnace increases from 1520℃-1530℃ to above 1540℃; (3) Smelting control: The gear position is controlled by 2±1 gears, high voltage operation, and the secondary voltage increases by 5-10V; (4) Slag shape optimization and adjustment: The manganese content in the slag is controlled at 4.5%-6%, the SiO2 content in the slag is controlled at 28%-32%, the slag basicity is controlled at 0.55-0.65, and the Al2O3 content in the slag is controlled at 18%-22%; When the manganese content in the slag is greater than 6%, add coke or insert electrodes; When the Al2O3 content in the slag is greater than 18% and the SiO2 content in the slag is greater than 32%, reduce the amount of silica; When the Al2O3 content in the slag is greater than 18% and the SiO2 content in the slag is between 28% and 32%, reduce the amount of coke used; (5) Clean the furnace regularly: Regular furnace cleaning is carried out every 10-15 days, using dolomite, limestone or calcium chloride to wash the furnace, and each batch of materials is increased by 40-50kg.