WO2019001181A1 - Blast furnace smelting method for high-grade, vanadium rich, chromium-bearing vanadium–titanium magnetite (cvtm) concentrate - Google Patents

Abstract

A blast furnace smelting method for high-grade, vanadium rich, chromium-bearing vanadium-titanium magnetite (CVTM) concentrate. The method is carried out according to the following steps : (1) mixing high-grade, vanadium rich, CVTM concentrate powder, iron concentrate powder, magnesite, lime, return fines, and a fuel to produce high-magnesium sintered ore; (2) pressing the high-grade, vanadium rich, CVTM concentrate powder, bentonite, and the fuel into pellets; (3) mixing the high-magnesium sintered ore and the pellets, and adding lump iron ore to form a blast furnace charge; (4) initiating blast furnace smelting, comprising configuring a charging system, an air supply system, a heating system, and a slagging system with a wind temperature of 1100-1200°C, a coke ratio of 330-380 kg/t, and a coal ratio of 160-200 kg/t; and (5) discharging molten iron once every 70-90 min with a molten iron temperature of 1430-1500°C.

Description

Blast furnace smelting method for high grade high vanadium chromium-containing vanadium-titanium magnet concentrate Technical field

The invention belongs to the technical field of metallurgy, and particularly relates to a blast furnace smelting method for high-grade high vanadium chromium-containing vanadium-titanium magnetite concentrate.

Background technique

High vanadium-containing chromium-type vanadium-titanium magnetite has a large reserve of vanadium resources and is widely distributed throughout the world, such as the Kulanagh mine in Russia, the Pangehong mine in China, and the Chengde super-poor mine, although in recent years, it has been targeted at vanadium and titanium. The research on non-blast furnace process of magnetite has achieved some research results, but the blast furnace process is still the most important process for realizing large-scale industrial utilization of vanadium-titanium magnetite resources for a while and for some time. In order to realize high-level large-scale development and utilization of high vanadium-containing chromium-type vanadium-titanium magnetite resources, comprehensive recovery of valuable components such as iron, vanadium, titanium and chromium, and high-grade high vanadium-containing chromium-type vanadium-titanium magnets It is imperative to carry out high-efficiency smelting of blast furnaces (60% <TFe < 67%, 0.3% < V ₂ O ₅ < 1.5%, 0.2% < Cr ₂ O ₃ <1.0%, 2.0% < TiO ₂ <12.0%).

High-grade high-chromium containing vanadium and titanium, vanadium magnetite concentrate of TiO ₂ and Al ₂ O ₃ content higher, will lead blast furnace blast slag content of TiO ₂ and Al ₂ O ₃ is increased, resulting in increased slag viscosity This leads to a series of problems such as reduced slag desulfurization capacity and difficulty in slag separation. The V ₂ O ₅ contained in the high-grade high-vanadium-containing chromium-type vanadium-titanium magnetite concentrate has obvious effect on the melting temperature of the slag, and Cr ₂ O ₃ also has an effect. The high-temperature viscosity of the slag generally increases first and then decreases. .

Summary of the invention

The object of the present invention is to provide a blast furnace smelting method for high-grade high-vanadium chromium-containing vanadium-titanium magnetite concentrate, which is capable of producing high-quality vanadium-containing molten iron by adjusting ordinary blast furnace smelting and operating parameters, and providing necessary for converter steelmaking and vanadium extraction. System guarantee.

The method of the invention proceeds as follows:

1. Mix high-grade high vanadium-containing vanadium-titanium magnetite concentrate powder, iron concentrate powder, magnesite, lime, return mine and fuel, and the weight of high-grade high vanadium-containing chromium-type vanadium-titanium powder in all materials. The percentage is 20-60%, the weight percentage of iron concentrate powder is 15-20%, the weight percentage of magnesite is 1-5%, the weight percentage of lime is 5-10%, and the weight percentage of fuel is 4-6%. The rest is returned to the mine; all the mixed materials are sintered at 1230 ~ 1280 ° C for 40 ~ 55min to make high magnesium sintered ore;

2. Mixing high-grade high-vanadium-containing vanadium-titanium magnetite concentrate powder, bentonite and fine iron concentrate powder into pellets, and the weight percentage of high-grade high-vanadium-containing chromium-type vanadium-titanium powder in the pellet is 60 to 90%, the weight percentage of bentonite is 1 to 1.5%, and the rest is fine iron concentrate powder; the pellet is baked at 1120 to 1150 ° C for 20 to 40 minutes to form pellets;

3. Mixing high-magnesium sinter and pellets, adding lump iron ore to make blast furnace charge, the weight percentage of sinter in the blast furnace charge is 55-74%, and the weight percentage of pellets is 21-40%. The weight percentage of iron ore is 5-10%; the blast furnace charge and coke are respectively sieved by 5mm ore vibrating screen and 25mm coke vibrating sieve. The blast furnace charge and coke on the sieve are weighed and charged into the blast furnace; the coke added during charging The amount of coke is 330-380kg/t;

4. Start blast furnace smelting, including charging system, air supply system, heat system and slagging system; the specific operations are as follows:

4.1. The blast furnace charge is loaded into the blast furnace by means of the dump truck;

4.2. When blast furnace smelting, the actual wind speed of the control tuyere is 170-200m/s, the wind temperature is 1100～1200°C, the temperature of the vault is controlled at 1245～1285°C, the air supply temperature is not lower than 1000°C, and the temperature during combustion is not more than 1300°C. , control exhaust gas temperature ≤ 350 ° C, flue gas oxygen content <0.5%, net gas pressure ≥ 5KPa; hot blast stove air supply time is 50 ~ 100min;

4.3. The raw coal is ground by a coal mill to a coal powder of -200 mesh, which accounts for more than 70% of the total weight. When the blast furnace is smelted, the amount of coal powder that is fed into the blast furnace is 160-200 kg/t according to the coal ratio;

4.4. When smelting slag in blast furnace, the melting temperature of slag is controlled at 1300~1400°C, the viscosity at 1400°C is less than 10Pa·s, the binary alkalinity is controlled at 1.15～1.20, and the mass percentage of MgO is 13～15%. The mass percentage of TiO ₂ is 5 to 20%, the mass percentage of Al ₂ O ₃ is 12 to 16%, and the mass percentage of V ₂ O ₅ is 0.1 to 0.3%;

5. The molten iron is ironed every 70~90min; the opening machine is ready to hit the iron mouth 5 minutes before the tapping, and the iron is started. The molten iron and slag are obtained through the main ditch and the skimmer to complete the blast furnace smelting; the molten iron temperature is 1430～1500°C. The molten iron contains 0.30 to 0.60% of silicon, 0.015 to 0.030% of sulfur, 0.15 to 0.30% of Ti, and 0.25 to 0.60% of V by weight.

In the above method, the yield of metal Fe is ≥98%, the yield of V is ≥80%, and the yield of Ti is ≥85%.

The above pellets have a particle size of 8 to 25 mm.

The above-mentioned high-grade high-vanadium-containing chromium-type vanadium-titanium magnet concentrate concentrate has an iron grade TFe of 58 to 68%, a basicity of 0.2 to 0.5, and a TiO _{2 content of} 4 to 12% by weight and a Cr ₂ O ₅ 0.1 to 1 by weight. %, V ₂ O ₅ 0.2% to 1.5%; wherein the high vanadium-containing chromium-type vanadium-titanium magnet concentrate powder in step 1 has a particle size of ≤0.5 mm, and the portion having a particle size of <0.048 mm accounts for ≥50% of the total weight, in step 2 The high vanadium-containing chromium-type vanadium-titanium magnet concentrate particle size is ≤0.5 mm, and the portion having a particle size of <0.048 mm accounts for ≥75% of the total weight.

The above iron concentrate powder iron grade TFe is 55-65%, and the particle size is ≤0.5 mm.

The above-mentioned fine iron concentrate powder iron iron grade TFe is 55-65%, the particle size is ≤0.5 mm, and the part of the particle size <0.048 mm accounts for ≥75% of the total weight.

The above magnesite contains MgO ≥ 30% by weight and particle size ≤ 2 mm.

The above-mentioned massive iron ore has an iron grade TFe of 30 to 60% and a particle size of 6 to 40 mm.

In the above method, when blast furnace smelting, if the wind temperature is to be lowered, it should not be lower than 900 °C, and the air temperature difference before and after the furnace change is ≤30 °C; the dust content of the gas used is ≤10 mg/m ³ , and the wind temperature fluctuation does not exceed 30 °C.

In the above method, the temperature at which the slag can be operated during slag formation is greater than 150 °C.

In the above method, after the iron is finished, the mud gun is blocked on the iron mouth; the mud gun stays in the blocking position for 15 to 20 minutes and then the gun is removed; the depth of the iron mouth is 1800-2000 mm, and the ladle is provided 15 minutes before the tapping.

The principle of the invention is:

In the actual blast furnace, the reduction of V is mainly carried out in the process of soft melt dripping and slag-iron. In the soft-melting drip zone, the reduction process of V is accelerated due to the appearance of liquid phase, so the alkalinity of sinter is improved. The improvement of the integrated charge drop performance promotes the reduction of V.

In addition, when Si is present, the vanadium oxide reduction reaction can occur as follows:

2VO+Si=2V+SiO ₂ , ΔG ^θ = -122362+37.5T(J/mo l) (4)

The Si reduction reaction produces SiO ₂ , and the low-valent vanadium oxide is a basic oxide, which adversely affects the reduction of vanadium. When CaO is present, the thermodynamic conditions of the reduced vanadium oxide are changed, and the reaction is as follows:

It can be seen that the presence of CaO improves the conditions for silicon reduction of vanadium oxide. The increase of sinter alkalinity increases the CaO content in the sinter and the SiO ₂ content does not change, thus promoting the reduction of vanadium by silicon. In summary, the increase in sinter alkalinity in the integrated charge is beneficial to the reduction of V element.

On the other hand, adding a certain amount of MgO flux to the furnace charge is an effective measure to ensure good slag, good desulfurization capacity and alkali discharge rate of slag during smelting of chromium-containing vanadium-titanium magnetite. By studying the influence of MgO on the metallurgical properties of high-grade high vanadium chromium-containing vanadium-titanium sinter and high-grade high-vanadium chromium-containing vanadium-titanium pellets, it is considered that the blast furnace smelting high-grade high vanadium-containing chromium-type vanadium-titanium magnetite is reasonable. Slag ore with high MgO content and pellets with low MgO content should be used in the charge structure.

When the content of MgO in the sinter is increased, the V content and the yield of V reduced to molten iron are reduced; the variation of Cr is consistent with V; when MgO is increased, magnesium ferrite is formed, and the amount of ferric acid is increased. The less the calcium content, the lower the reduction performance; and the reduction of Fe and the reduction of V show a positive correlation. On the one hand, the reduction of V in Fe is reduced, on the other hand, the dripping rate of slag iron is small, and the yield of V decreases with the increase of MgO content; the mechanism of Cr changes with MgO is similar to V.

According to the research, with the increase of binary alkalinity, the slag melting temperature, initial viscosity and high temperature viscosity generally decrease first and then increase. With the increase of MgO content, the slag melting temperature decreases first and then increases. The viscosity and high temperature viscosity generally decreased first and then increased. With the increase of Al ₂ O ₃ content, the slag melting temperature increased, the initial viscosity decreased first and then increased, and the high temperature viscosity generally increased. With the increase of TiO ₂ content, The slag melting temperature showed a significant upward trend, and the initial viscosity and high temperature viscosity showed a general downward trend. With the increase of V ₂ O ₅ content, the slag melting temperature decreased first and then increased. The initial viscosity and high temperature viscosity were generally rising trend.

It is found that the Al ₂ O ₃ content has the greatest influence on the high-temperature viscosity of high-grade high vanadium-containing vanadium-titanium magnetite concentrate blast furnace slag, followed by alkalinity, followed by MgO content, followed by TiO ₂ content, followed by V ₂ O ₅ , the last is Cr ₂ O ₃ ; for the lower high temperature viscosity, the optimal combination is: alkalinity 1.15 ~ 1.20, MgO content 13 ~ 15%, TiO ₂ content 8 ~ 20%, Al ₂ O ₃ content 12 to 16%. Reasonable high-grade high vanadium-containing chromium-type vanadium-titanium magnet concentrate blast furnace smelting structure and the influence of introduction of Cr ₂ O ₃ on the performance of titanium-containing blast furnace slag due to the use of new vanadium-titanium magnetite resources and its normal slag iron The problems of separation and other effects require the development of high-efficiency smelting technology for the blast furnace.

The good slag iron is an important link to promote the stability of the furnace and ensure the safety, stability and high yield of the blast furnace. Appropriately increase the slag basicity and the MgO content in the slag to ensure the physical heat and fluidity of the slag iron and the desulfurization capacity of the slag. On the basis of ensuring the smoothness of the furnace condition, the loading method of excessive development of the edge or central gas should be minimized, that is, the air flow between the center and the edge should be ensured, and the heat energy and chemical energy of the gas should be utilized to the utmost extent; Reduce to the required level, but not lower than 900 °C wind temperature stress to stabilize, the wind temperature difference before and after the furnace should be no more than 30 °C.

Compared with the prior art, the invention has the following effects:

1. Increasing the proportion of high vanadium chromium-containing vanadium-titanium magnetite concentrate in blast furnace smelting raw materials, reducing the cost of iron making;

2. The silicon content of pig iron is reduced, and the average value of pig iron composition is divided into L04-2 grade iron according to national standard, and the vanadium content exceeds the national vanadium-bearing pig iron standard;

3. Improve the alkalinity of slag, realize “chemical cool, physical heat”, increase the number of iron discharge, reduce the residence time of slag in the furnace, ensure the condition of the furnace, and obtain better technical indicators;

4. The utilization coefficient of the blast furnace is increased to 3.7-4.0t/m ³ ·d, the coal ratio is increased, the comprehensive coke ratio is greatly reduced, and the metal yield is kept at a high level.

DRAWINGS

1 is a schematic flow chart of a blast furnace smelting method for a high-grade high-vanadium-containing chromium-containing vanadium-titanium magnet concentrate according to an embodiment of the present invention.

Detailed ways

The massive iron ore used in the embodiment of the present invention is a common massive iron ore containing no vanadium and titanium.

The iron fine powder and the fine iron concentrate powder used in the examples of the present invention do not contain vanadium and titanium.

The fuel in the embodiment of the invention is a coke breeze, the carbon content is ≥80%, and the particle size is ≤3 mm.

The coke particle size used in the examples of the present invention is 25-60 mm, the strength after coke reaction (CSR) is ≤35%, and the coke reactivity (CRI) is ≥55%.

In the embodiment of the present invention, when the blast furnace charge is charged into the blast furnace, the charging system of the blast furnace type is inverted, and the difference between the two feet is not more than 0.5 m, and the material line is regularly corrected, and the normal material line is specified to be 0.6 to 1.5 meters; The allowable error of the raw materials into the furnace is: coke ≤ 10kg, ore ≤ 20kg.

The lime powder in the embodiment of the present invention is commercially available, and contains CaO ≥ 80% by weight and a particle size ≤ 2 mm.

The particle size of the pellets in the embodiment of the present invention is 8 to 25 mm.

The high-grade high-vanadium-containing chromium-type vanadium-titanium magnet concentrate concentrate in the embodiment of the present invention has an iron grade TFe of 58 to 68%, and contains TiO ₂ 4 to 12% by weight, Cr ₂ O ₅ 0.1 to 1%, and V. ₂ O ₅ 0.2%～1.5%; wherein the high vanadium-containing chromium-type vanadium-titanium magnet concentrate powder in step 1 has a particle size of ≤0.5 mm, and the portion with a particle size of <0.048 mm accounts for ≥50% of the total weight, and the high vanadium in step 2 The chromium-containing vanadium-titanium magnet concentrate powder has a particle size of ≤0.5 mm, and the portion having a particle size of <0.048 mm accounts for ≥75% of the total weight.

The ordinary iron concentrate powder iron grade TFe in the embodiment of the invention is 55-65%, and the particle size is ≤0.5 mm.

The fine iron concentrate powder iron iron grade TFe in the embodiment of the invention is 55-65%, the particle size is ≤0.5 mm, and the partial portion with the particle size <0.048 mm accounts for ≥75% of the total weight.

The magnesite in the embodiment of the invention contains MgO ≥ 30% by weight and particle size ≤ 2 mm.

The iron ore content TFe of the massive iron ore in the embodiment of the present invention is 30 to 60%, and the particle size is 6 to 40 mm.

In the embodiment of the present invention, when blast furnace smelting, if the wind temperature is to be lowered, the temperature should not be lower than 900 ° C, and the air temperature difference before and after the furnace change is ≤ 30 ° C; the dust content of the gas used is ≤ 10 mg / m ³ , and the wind temperature fluctuation does not exceed 30 ° C.

In the embodiment of the invention, after the iron is finished, the mud gun is blocked by the iron mouth; the mud gun stays in the blocking position for 15-20 minutes and then the gun is removed; the depth of the iron mouth is 1800-2000 mm, and the ladle is provided 15 minutes before the tapping.

Example 1

Mix high-grade high vanadium-containing vanadium-titanium magnetite concentrate powder, iron concentrate powder, magnesite, lime, return mine and fuel. The weight percentage of high-grade high vanadium-containing chromium-type vanadium-titanium powder in all materials is 20%, the weight percentage of iron concentrate powder is 20%, the weight percentage of magnesite is 5%, the weight percentage of lime is 10%, the weight percentage of fuel is 6%, and the rest is returning; all materials after mixing Sintered at 1230 ° C for 55 min to produce a high-magnesium sintered ore;

Mixing high-grade high vanadium-containing vanadium-titanium magnetite concentrate powder, bentonite and fine iron concentrate powder into pellets, the weight percentage of high-grade high-vanadium-containing chromium-type vanadium-titanium powder in the pellet is 90% The weight percentage of bentonite is 1.5%, and the rest is fine iron concentrate powder; the pellet is baked at 1140 ° C for 25 minutes to form pellets;

The high-magnesium sinter and the pellets are mixed and added to the lump ore to form a blast furnace charge. The weight percentage of the sintered ore in the blast furnace charge is 55%, the weight percentage of the pellet is 40%, and the weight percentage of the lump iron ore is 5%; blast furnace charge and coke are respectively sieved by 5mm ore vibrating screen and 25mm coke vibrating screen. The blast furnace charge and coke on the sieve are weighed and charged into the blast furnace; the amount of coke added during charging is 340kg/ t;

Start blast furnace smelting, including charging system, air supply system, heat system and slagging system; the specific operations are as follows:

1. The blast furnace charge is loaded into the blast furnace by means of the dump truck;

2. When blast furnace smelting, the actual wind speed of the control tuyere is 170m/s, the wind temperature is 1200°C, the temperature of the vault is controlled at 1285°C, the air supply temperature is not lower than 1000°C, the temperature during combustion does not exceed 1300°C, and the temperature of the exhaust gas is controlled to ≤350. °C, the oxygen content of the flue gas is <0.5%, the net gas pressure is ≥5KPa; the air supply time of the hot blast stove is 50min;

3. The raw coal is ground by a coal mill to a coal powder of -200 mesh, which accounts for more than 70% of the total weight. When the blast furnace is smelted, the amount of coal powder that is fed into the blast furnace is 160 kg/t according to the coal ratio;

4. When smelting slag in blast furnace, the melting temperature of slag is 1350 °C, the viscosity of slag at 1400 °C is 9.1 Pa·s, the binary alkalinity is controlled at 1.15, the mass percentage of MgO is 13%, and the mass percentage of TiO ₂ is 6. %, the mass percentage of Al ₂ O ₃ is 12%, and the mass percentage of V ₂ O ₅ is 0.13%;

The molten iron is ironed once every 70 minutes; the opening machine is ready to hit the iron mouth 5 minutes before the tapping, the iron is started, the molten iron and the slag are obtained through the main ditch and the skimmer, and the blast furnace smelting is completed; the molten iron temperature is 1480 ° C, and the molten iron is silicon-containing by weight. 0.30%, sulfur 0.025%, Ti 0.15%, V 0.25%, metal Fe yield 98%, V yield 95%, Ti yield 80%; the process is shown in Figure 1.

Example 2

The method is the same as that in Embodiment 1, except that:

(1) Mixing high-grade high vanadium-containing vanadium-titanium magnetite concentrate powder, iron concentrate powder, magnesite, lime, returning or fuel, and high-grade high vanadium-containing chromium-type vanadium-titanium powder in all materials. The weight percentage is 50%, the iron concentrate powder is 15% by weight, the magnesite is 1% by weight, the lime is 5% by weight, the fuel is 4% by weight, and the rest is returned; after mixing All the materials were sintered at 1280 ° C for 40 min to make high magnesium sinter;

(2) The high-grade high vanadium-containing chromium-type vanadium-titanium magnet concentrate powder in the pellet is 60% by weight, the bentonite is 1% by weight, and the balance is fine iron concentrate powder; the pellet is sintered at 1130 °C. 30 minutes, made into pellets;

(3) The weight percentage of the sintered ore in the blast furnace charge is 74%, the weight percentage of the pellet is 21%, the weight percentage of the lump iron ore is 5%; the coke amount added during the charging is 350 kg/t according to the coke ratio;

(4) When blast furnace smelting, the actual wind speed of the control tuyere is 180m/s, the wind temperature is 1160°C, the temperature of the vault is controlled at 1275°C, and the air supply time of the hot blast stove is 60min;

(5) The coal ratio is 170kg/t;

(6) When smelting slag in blast furnace, the melting temperature of slag is 1400 °C, the viscosity of slag at 1400 °C is 8.9 Pa·s, the binary alkalinity is controlled at 1.18, the mass percentage of MgO is 15%, and the mass percentage of TiO ₂ is 9%, the mass percentage of Al ₂ O ₃ is 16%, and the mass percentage of V ₂ O ₅ is 0.10%;

(7) The molten iron is ironed once every 75 minutes; the molten iron temperature is 1450 °C, the molten iron contains 0.60% silicon, sulfur 0.022%, Ti 0.30%, V 0.43%, the yield of metal Fe is 99%, and the yield of V is 94%, Ti's yield is 83%.

Example 3

The method is the same as that in Embodiment 1, except that:

(1) Mixing high-grade high vanadium-containing vanadium-titanium magnetite concentrate powder, iron concentrate powder, magnesite, lime, returning or fuel, and high-grade high vanadium-containing chromium-type vanadium-titanium powder in all materials. The weight percentage is 60%, the iron concentrate powder is 19% by weight, the magnesite is 4% by weight, the lime is 6% by weight, the fuel is 5% by weight, and the rest is returned; after mixing The whole material is sintered at 1250 ° C for 50 min to form a high-magnesium sintered ore;

(2) The high-grade high-vanadium-containing chromium-type vanadium-titanium magnet concentrate powder in the pellet is 70% by weight, the bentonite is 1.2% by weight, and the rest is fine iron concentrate powder; the pellet is sintered at 1150 °C. 20 minutes, made into pellets;

(3) The weight percentage of the sintered ore in the blast furnace charge is 55%, the weight percentage of the pellet is 35%, the weight percentage of the lump iron ore is 10%; the coke amount added during the charging is 380 kg/t according to the coke ratio;

(4) When blast furnace smelting, the actual wind speed of the control tuyere is 190m/s, the wind temperature is 1130°C, the temperature of the vault is controlled at 1260°C, and the air supply time of the hot blast stove is 80min;

(5) The coal ratio is 180kg/t;

(6) When smelting slag in blast furnace, the melting temperature of slag is 1400 °C, the viscosity of slag at 1400 °C is 8.9 Pa·s, the binary alkalinity is controlled at 1.18, the mass percentage of MgO is 14%, and the mass percentage of TiO ₂ is 18%, the mass percentage of Al ₂ O ₃ is 15%, and the mass percentage of V ₂ O ₅ is 0.12%;

(7) The molten iron is ironed once every 80 minutes; the molten iron temperature is 1500 °C, the molten iron contains 0.50% of silicon, 0.030% of sulfur, 0.25% of Ti, 0.60% of V, the yield of metal Fe is 99%, and the yield of V is 97%, Ti's yield is 81%.

Example 4

The method is the same as that in Embodiment 1, except that:

(1) Mixing high-grade high vanadium-containing vanadium-titanium magnetite concentrate powder, iron concentrate powder, magnesite, lime, returning or fuel, and high-grade high vanadium-containing chromium-type vanadium-titanium powder in all materials. The weight percentage is 40%, the iron concentrate powder is 18% by weight, the magnesite is 4% by weight, the lime is 9% by weight, the fuel is 5% by weight, and the rest is returned; after mixing The entire material is sintered at 1270 ° C for 45 min to form a high-magnesium sintered ore;

(2) The high-grade high-vanadium-containing chromium-type vanadium-titanium magnet concentrate powder in the pellet is 80% by weight, the bentonite is 1.4% by weight, and the balance is fine iron concentrate powder; the pellet is sintered at 1120 °C. 40 min, made into pellets;

(3) The weight percentage of the sintered ore in the blast furnace charge is 60%, the weight percentage of the pellet is 32%, the weight percentage of the lump iron ore is 8%; the coke amount added during the charging is 330 kg/t according to the coke ratio;

(4) When blast furnace smelting, the actual wind speed of the control tuyere is 200m/s, the wind temperature is 1100°C, the temperature of the vault is controlled at 1245°C, and the air supply time of the hot blast stove is 100min;

(5) The coal ratio is 200kg/t;

(6) When smelting slag in blast furnace, the melting temperature of slag is 1400 °C, the viscosity of slag at 1400 °C is 8.9 Pa·s, the binary alkalinity is controlled at 1.18, the mass percentage of MgO is 13%, and the mass percentage of TiO ₂ is 12%, the mass percentage of Al ₂ O ₃ is 16%, and the mass percentage of V ₂ O ₅ is 0.11%;

(7) The molten iron is ironed once every 90 minutes; the molten iron temperature is 1430 °C, the molten iron contains 0.40% silicon, the sulfur is 0.015%, the Ti 0.19%, the V 0.36%, the metal Fe yield is 99%, and the V yield is 97%, Ti's yield is 82%.

Claims (8)

1. A blast furnace smelting method for high-grade high-vanadium-containing chromium-type vanadium-titanium magnet concentrate, which is characterized by the following steps:

   (1) Mix high-grade high-vanadium-containing vanadium-titanium magnetite concentrate powder, iron concentrate powder, magnesite, lime, return mine and fuel, and high-grade high-vanadium-containing chromium-type vanadium-titanium magnet concentrate in all materials. The weight percentage of the powder is 20-60%, the weight percentage of the iron concentrate powder is 15-20%, the weight percentage of the magnesite is 1-5%, the weight percentage of the lime is 5-10%, and the weight percentage of the fuel is 4. ~6%, the rest is returning to the mine; all the mixed materials are sintered at 1230 ~ 1280 °C for 40 ~ 55min, to make high-magnesium sintered ore;

   (2) mixing high-grade high vanadium-containing vanadium-titanium magnetite concentrate powder, bentonite and fine iron concentrate powder into pellets, high-grade high vanadium-containing chromium-type vanadium-titanium magnet concentrate concentrate in pellets The weight percentage is 60-90%, the weight percentage of bentonite is 1-11.5%, and the rest is fine iron concentrate powder; the pellet is sintered at 1120～1150°C for 20-40 minutes to form pellets;

   (3) mixing high-magnesium sinter and pellets, adding lump iron ore to make blast furnace charge, the weight percentage of sinter in the blast furnace charge is 55-74%, and the weight percentage of pellets is 21-40%. The weight percentage of lump iron ore is 5-10%; the blast furnace charge and coke are respectively sieved by 5mm ore vibrating sieve and 25mm coke vibrating sieve, and the blast furnace charge and coke on the sieve are weighed and then charged into the blast furnace; The coke amount is 330-380kg/t according to the coke ratio;

   (4) Start blast furnace smelting, including charging system, air supply system, heat system and slagging system; the specific operations are as follows:

   (4.1) loading the blast furnace charge into the blast furnace by means of the dump truck;

   (4.2) When blast furnace smelting, the actual wind speed of the control tuyere is 170-200 m/s, the wind temperature is 1100-1200 °C, the dome temperature is controlled at 1245~1285 °C, the supply air temperature is not lower than 1000 °C, and the combustion temperature does not exceed 1300. °C, control exhaust gas temperature ≤350 °C, flue gas oxygen content <0.5%, net gas pressure ≥5KPa; hot blast stove air supply time is 50-100min;

   (4.3) The raw coal is ground by a coal mill to a coal powder of -200 mesh, which accounts for more than 70% of the total weight. When the blast furnace is smelted, the amount of coal powder introduced into the blast furnace is 160-200 kg/t according to the coal ratio;

   (4.4) When smelting slag in blast furnace, the melting temperature of slag is controlled at 1300 ~ 1400 °C, the viscosity at 1400 °C is <10Pa·s, the binary alkalinity is controlled at 1.15~1.20, and the mass percentage of MgO is 13-15%. , the mass percentage of TiO ₂ is 6 to 20%, the mass percentage of Al ₂ O ₃ is 12 to 16%, and the mass percentage of V ₂ O ₅ is 0.1 to 0.3%;

   (5) The molten iron is ironed every 70~90min; the opening machine is ready to hit the iron mouth 5 minutes before the tapping, and the iron is started. The molten iron and slag are obtained through the main ditch and the skimmer to complete the blast furnace smelting; the molten iron temperature is 1430～1500°C. According to the weight percentage, molten iron contains 0.30-0.60% silicon, sulfur 0.015-0.030%, Ti 0.15-0.30%, and V 0.25-0.60%.
2. The blast furnace smelting method for a high-grade high-vanadium-containing chromium-containing vanadium-titanium magnetite concentrate according to claim 1, characterized in that the yield of metal Fe is ≥98%, the yield of V is ≥80%, and Ti The yield is ≥85%.
3. The blast furnace smelting method of a high-grade high-vanadium-containing chromium-containing vanadium-titanium magnetite concentrate according to claim 1, wherein the pellet has a particle size of 8 to 25 mm.
4. A blast furnace smelting method for a high-grade high-vanadium-containing chromium-containing vanadium-titanium magnetite concentrate according to claim 1, wherein said high-grade high vanadium-containing chromium-type vanadium-titanium magnetite concentrate has an iron grade TFe of 58 ～68%, containing TiO ₂ 4～12%, Cr ₂ O ₅ 0.1～1%, V ₂ O ₅ 0.2%～1.5% by weight percentage; wherein the high vanadium-containing chrome-type vanadium-titanium magnet in step (1) The particle size of the ore powder is ≤0.5mm, and the part with the particle size of <0.048mm accounts for ≥50% of the total weight, and the part of the high vanadium-containing vanadium-titanium magnetite concentrate powder in the step (2) is ≤0.5mm, and the part with the particle size of <0.048mm The total weight is ≥75%.
5. The blast furnace smelting method for a high-grade high-vanadium-containing chromium-containing vanadium-titanium magnetite concentrate according to claim 1, characterized in that the iron concentrate powder has a TFE of 55 to 65% and a particle size of ≤ 0.5 mm.
6. The blast furnace smelting method for a high-grade high-vanadium-containing chromium-containing vanadium-titanium magnetite concentrate according to claim 1, wherein the fine iron concentrate powder iron iron grade TFe is 55-65%, and the particle size is ≤0.5. Mm, and the portion of the particle size <0.048 mm accounts for ≥75% of the total weight.
7. The blast furnace smelting method for a high-grade high-vanadium-containing chromium-containing vanadium-titanium magnetite concentrate according to claim 1, wherein the magnesite contains MgO ≥ 30% by weight and a particle size ≤ 2 mm.
8. The blast furnace smelting method for a high-grade high-vanadium-containing chromium-containing vanadium-titanium magnetite concentrate according to claim 1, characterized in that the iron ore content TFe of the massive iron ore is 30 to 60%, and the particle size is 6 to 40 mm. .

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