A method for reducing iron loss in high-titanium slag during blast furnace smelting

Abstract

The present invention provides a method for reducing iron loss in high-titanium slag during blast furnace smelting, which relates to the technical field of blast furnace smelting. The burden is proportioned with a raw-to-clinker weight ratio of 3:97, and the silicon-titanium mass ratio of the proportioned burden is controlled within a preset range. During smelting, the blast volume, blast temperature, and oxygen enrichment rate into the furnace are controlled within a preset range, and the slag basicity, magnesium-aluminum ratio, and hot metal temperature are controlled within a preset range. In the present invention, the clinker in the burden is maintained at 97%. By controlling the blast volume, blast temperature, and high oxygen enrichment rate into the furnace, the generation of metallic [Ti] is reduced. The silicon-titanium mass ratio in the burden is 0.18 - 0.28, enabling the blast furnace slag to have desulfurization ability under the condition of silicon-titanium smelting. Controlling the silicon-titanium level within the range of 0.18 - 0.28 inhibits the reduction of [Ti], thereby reducing TiNC and TiN, improving the slag fluidity, reducing the difficulty of slag-iron separation, and thus reducing iron loss.

Description

Technical Field

[0001] The invention belongs to the technical field of blast furnace smelting, and particularly relates to a method for reducing iron loss in high-titanium slag during blast furnace smelting. Background Art

[0002] Blast furnace smelting of high titanium slag is one of the important processes for the extraction of titanium resources. However, in the process of smelting high titanium slag, due to the high The special properties of high-titanium content and high-titanium ore often lead to a significant increase in iron loss in the blast furnace, seriously affecting smelting efficiency and economic benefits;

[0003] The main reason for high iron loss is that the slag takes away iron during slag discharge. In the smelting of high vanadium-titanium ratio blast furnace, as the vanadium-titanium ratio increases, the concentration of titanium dioxide in the slag also increases. Under the high temperature and high reducing atmosphere of the blast furnace, titanium dioxide will be reduced to [Ti] and will be brought in by the blast. It reacts with the carbon in the coke / coal powder to generate high melting point TiNC. TiN enters the slag, which greatly increases the viscosity of the slag, making it more difficult to separate the slag from the iron, thereby increasing the iron loss.

[0004] The conventional method to reduce the titanium dioxide content in the slag is to reduce the ratio of vanadium to titanium in the furnace. However, reducing the ratio of vanadium to titanium in the furnace will inevitably lead to an increase in the cost per ton of iron and the yield of vanadium. Therefore, it is necessary to reduce iron loss without reducing the ratio of vanadium to titanium in the furnace. In addition, since the titanium dioxide in the slag is weakly acidic and the molten iron temperature is relatively low, between 1420-1460°C, the desulfurization capacity of the slag is relatively weak.

[0005] Therefore, the present invention proposes a method that can effectively reduce the iron loss during the smelting process of high-titanium slag in the blast furnace without affecting the desulfurization capacity of the blast furnace. Summary of the invention

[0006] The present invention provides a method for reducing iron loss in high-titanium slag during blast furnace smelting, so as to solve at least one of the technical problems mentioned above.

[0007] In order to solve the above technical problems, the present invention discloses a method for reducing iron loss in high-titanium slag during blast furnace smelting, comprising:

[0008] The charge is mixed in a weight ratio of 3:97 between raw and clinker, and the silicon-titanium mass ratio of the charge is controlled within a preset range. During smelting, the air volume, air temperature and oxygen enrichment rate entering the furnace are controlled within a preset range, and the slag basicity, magnesium-aluminum ratio and molten iron temperature are controlled within a preset range.

[0009] Preferably, the weight ratio of the charge is 52-55% pellets, 42-45% sintered ore and 3% green ore.

[0010] Preferably, the mass ratio of silicon to titanium in the charge is 0.18-0.28.

[0011] Preferably, the preset range of the blast volume entering the furnace during smelting is 3350 - 3400 / min;

[0012] The preset range of the blast temperature entering the furnace is 1215 - 1230 °C;

[0013] The preset range of the oxygen enrichment rate entering the furnace is 4.5 - 6%.

[0014] Preferably, the preset range of the slag basicity is 1.10 ± 0.05;

[0015] The preset range of the magnesium - aluminum ratio is 0.62 - 0.65;

[0016] The preset range of the hot metal temperature is 1420 - 1460 °C.

[0017] Preferably, it further includes: controlling the proportion of powders with a particle size less than or equal to 5 mm in the powders entering the furnace to be less than 2%;

[0018] The smelting cycle is controlled within 6 h;

[0019] The smelting blast furnace adopts a 1250 blast furnace.

[0020] Preferably, it further includes conducting spot checks on the iron loss batches. Specifically:

[0021] Construct the historical weekly batch iron loss distribution data, and based on the historical weekly batch iron loss distribution data, screen out all the main iron loss monitoring batches in the current smelting week, and conduct spot checks based on the smelting results of the corresponding batches of all the main iron loss monitoring batches.

[0022] Preferably, constructing the historical weekly batch iron loss distribution data includes:

[0023] Maintain a raw - to - clinker weight ratio of 3:97 for the furnace charge, conduct blast furnace smelting for several consecutive weeks, collect the iron content in the final smelting of each batch every week, calculate the iron loss rate of each batch every week based on the iron content in the final smelting of each batch every week, and form the historical weekly batch iron loss distribution data;

[0024] Among them, calculating the iron loss rate of each batch every week based on the iron content in the final smelting of each batch every week:

[0025] ; where, is the iron loss rate of the i - th batch in the th week, is the feeding amount of the i - th batch in the th week, is the mass fraction of iron in the feed, is the The iron content in the final smelting of the i-th batch in a week;

[0026] Based on the historical weekly batch iron loss distribution data, all the main iron loss monitoring batches in the current smelting week are screened out, including:

[0027] Calculate the importance of each batch:

[0028] ; where is the importance of the i-th batch, represents the number of times the iron loss rate in the i-th batch exceeds the standard in several weeks, represents the maximum iron loss rate in the i-th batch in several weeks, represents the minimum iron loss rate in the i-th batch in several weeks, is the preset limit iron loss rate, is the compensation coefficient for the influence of the air volume entering the furnace, is the compensation coefficient for the influence of the blast temperature entering the furnace, is the compensation coefficient for the influence of the oxygen enrichment rate entering the furnace, is the natural logarithm with base e;

[0029] When the importance of one of the batches is greater than the preset importance, this batch is used as the main iron loss monitoring batch;

[0030] When conducting spot checks on iron loss batches, only the smelting results of the batches corresponding to all the main iron loss monitoring batches are spot-checked.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] (1) In the present invention, the clinker in the furnace charge is maintained at 97%. By controlling the air volume, blast temperature, and high oxygen enrichment rate entering the furnace, the smelting cycle of the furnace charge is shortened by 10%, realizing the "fast in and fast out" of the furnace charge, shortening the smelting process, reducing the generation of metal [Ti]. By controlling the slag basicity, magnesium-aluminum ratio, and hot metal temperature, the slag has good fluidity. The mass ratio of silicon to titanium in the furnace charge is 0.18 - 0.28. In the case of silicon-titanium smelting, the blast furnace slag has desulfurization ability. By stabilizing the raw materials entering the furnace and controlling the deviation of silicon-titanium in the furnace temperature ≤ 0.05 / shift, the ups and downs of high and low furnace temperatures are eliminated, and the silicon-titanium level is controlled within the range of 0.18 - 0.28 to inhibit the reduction of [Ti], thereby reducing TiNC and TiN, improving the fluidity of the slag, reducing the difficulty of slag-iron separation, and thus reducing iron loss, reducing the metal loss in the smelting process, and reducing the production cost;

[0033] (2) By constructing the historical weekly batch iron loss distribution data, calculating the importance of each batch, and screening out the main iron loss monitoring batches that need to be key inspected according to the importance, the present invention helps to improve the pertinence and effectiveness of iron loss monitoring, reduce unnecessary repeated inspections, and thus optimize the quality management in the smelting process; Description of the Drawings

[0034] The drawings are used to provide a further understanding of the present invention and form a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation to the present invention. In the drawings:

[0035] Figure 1 It is a schematic diagram of the method steps for reducing the iron loss in high-titanium slag during the blast furnace smelting of the present invention. Detailed Embodiments

[0036] The following describes the preferred embodiments of the present invention with reference to the drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention and are not used to limit the present invention.

[0037] In addition, in the present invention, descriptions such as "first" and "second" are only for descriptive purposes and do not particularly refer to the meaning of order or sequence. Nor are they used to limit the present invention. They are merely used to distinguish components or operations described with the same technical terms, and should not be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In addition, the technical solutions and technical features between various embodiments can be combined with each other, but it must be based on the ability of those of ordinary skill in the art to implement. When the combination of technical solutions results in contradictions or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0038] The present invention provides the following embodiments:

[0039] Embodiment 1

[0040] The embodiment of the present invention provides a method for reducing the iron loss in high-titanium slag during blast furnace smelting. As Figure 1 shown, the furnace burden is proportioned with a raw-to-clinker weight ratio of 3:97, and the silicon-titanium mass ratio of the proportioned furnace burden is controlled within a preset range. During smelting, the blast volume, blast temperature, and oxygen enrichment rate entering the furnace are controlled within a preset range, and the slag basicity, magnesium-aluminum ratio, and hot metal temperature are controlled within a preset range.

[0041] Preferably, the weight ratio of the furnace burden is 52-55% pellet ore, 42-45% sinter ore, and 3% raw ore.

[0042] Preferably, the silicon-titanium mass ratio in the furnace burden is 0.18-0.28.

[0043] Preferably, the preset range of the blast volume entering the furnace during smelting is 3350-3400 / min;

[0044] The preset range of the hot blast temperature entering the furnace is 1215 - 1230 °C;

[0045] The preset range of the oxygen enrichment rate entering the furnace is 4.5 - 6%.

[0046] Preferably, the preset range of the slag basicity is 1.10 ± 0.05;

[0047] The preset range of the magnesium - aluminum ratio is 0.62 - 0.65;

[0048] The preset range of the hot metal temperature is 1420 - 1460 °C.

[0049] Preferably, control the proportion of powders with a particle size less than or equal to 5 mm in the powders entering the furnace to be less than 2%;

[0050] The smelting cycle is controlled within 6 h;

[0051] The smelting blast furnace uses a 1250 blast furnace.

[0052] The working principle and beneficial effects of the above - mentioned technical solution are as follows: In the present invention, the clinker (pellets and sinter) in the furnace charge is maintained at 97%. By controlling the air volume, hot blast temperature and high oxygen enrichment rate entering the furnace, the smelting cycle of the furnace charge is shortened by 10%, realizing the "fast in and fast out" of the furnace charge, shortening the smelting stroke, reducing the generation of metal [Ti]. By controlling the slag basicity, magnesium - aluminum ratio and hot metal temperature, the slag has good fluidity. The mass ratio of silicon to titanium in the furnace charge is 0.18 - 0.28. In the case of silicon - titanium smelting, the blast furnace slag has desulfurization ability. By stabilizing the raw materials entering the furnace again and controlling the deviation of silicon - titanium in the furnace temperature ≤ 0.05 / shift, eliminating the fluctuation of high and low furnace temperatures, and controlling the silicon - titanium level in the range of 0.18 - 0.28 to inhibit the reduction of [Ti], further reducing TiNC and TiN, improving the slag fluidity, reducing the difficulty of slag - iron separation, thereby reducing iron loss, reducing the metal loss in the smelting process, and reducing the production cost.

[0053] Example 2

[0054] On the basis of Example 1, the furnace charge required for blast furnace smelting includes, by weight percentage: 55% pellets, 42% sinter and 3% raw ore. Control the proportion of powders with a particle size less than or equal to 5 mm in the powders entering the furnace to be less than 2%, and control the mass ratio of silicon to titanium in the furnace charge to be 0.18.

[0055] The working principle and beneficial effects of the above - mentioned technical solution are as follows: Feed the furnace charge into a 1250 blast furnace for smelting, control the smelting cycle within 6 h, so that the entering the furnace is maintained at 125 Kg / t, and control the residence time of the vanadium - titanium furnace charge in the blast furnace;

[0056] And control the following parameters during the smelting process: Control the air volume entering the furnace to be 3350 / min, high blast temperature of 1215°C, high oxygen enrichment rate of 4.5%, enabling the burden to quickly reach the hearth inside the blast furnace, reducing the reaction formation time of Ti, controlling the slag basicity at 1.10 ± 0.05, the magnesium-aluminum ratio at 0.62, and the hot metal temperature at 1420°C, so that the blast furnace slag has desulfurization ability under the smelting condition where the silicon-titanium mass ratio in the burden is 0.18 - 0.28.

[0057] Example 3

[0058] Based on Example 1, the burden required for blast furnace smelting includes by weight percentage: 52% pellet, 45% sinter, and 3% raw ore. Control the proportion of powder with a particle size less than or equal to 5 mm in the charged powder to be less than 2%, and control the silicon-titanium mass ratio in the burden at 0.28.

[0059] The working principle and beneficial effects of the above technical solution are: Feed the said burden into a 1250 blast furnace for smelting, control the smelting cycle within 6 h, so that the charge remains at 125 Kg / t, and control the residence time of the vanadium-titanium burden inside the blast furnace;

[0060] During the smelting process, control the following parameters: Control the charged air volume at 3400 / min, high blast temperature of 1230°C, high oxygen enrichment rate of 6%, enabling the burden to quickly reach the hearth inside the blast furnace, reducing the reaction formation time of Ti, controlling the slag basicity at 1.10 ± 0.05, the magnesium-aluminum ratio at 0.65, and the hot metal temperature at 1460°C, so that the blast furnace slag has desulfurization ability under the smelting condition where the silicon-titanium mass ratio in the burden is 0.18 - 0.28.

[0061] Example 4

[0062] Based on Example 1, it also includes conducting spot checks on the iron loss batches. Specifically:

[0063] Construct historical weekly batch iron loss distribution data, and based on the historical weekly batch iron loss distribution data, screen out all the main iron loss monitoring batches in the current smelting week, and conduct spot checks based on the smelting results of the corresponding batches of all the main iron loss monitoring batches.

[0064] Preferably, constructing the historical weekly batch iron loss distribution data includes:

[0065] Maintain a raw-to-clinker weight ratio of the burden of 3:97, conduct continuous blast furnace smelting for several weeks, collect the iron content of each batch in the final smelting every week, calculate the iron loss rate of each batch every week based on the iron content of each batch in the final smelting every week, and form the historical weekly batch iron loss distribution data;

[0066] Among them, calculate the iron loss rate of each batch every week based on the iron content of each batch in the final smelting every week:

[0067] ; where, is the iron loss rate of the i-th batch in the th week, is the feeding amount of the i-th batch in the th week, is the mass fraction of iron in the feed, is the iron content in the final smelting of the i-th batch in the th week;

[0068] Based on the historical weekly batch iron loss distribution data, all the main iron loss monitoring batches in the current smelting week are screened out, including:

[0069] Calculate the importance of each batch:

[0070] ; where, is the importance of the i-th batch, represents the number of times the iron loss rate of the i-th batch exceeds the standard in several weeks, represents the maximum iron loss rate in the i-th batch in several weeks, represents the minimum iron loss rate in the i-th batch in several weeks, is the preset limit iron loss rate, is the compensation coefficient for the influence of the blast volume into the furnace, is the compensation coefficient for the influence of the blast temperature into the furnace, is the compensation coefficient for the influence of the oxygen enrichment rate into the furnace, is the natural logarithm with base e;

[0071] When the importance of one of the batches is greater than the preset importance, this batch is used as the main iron loss monitoring batch;

[0072] When conducting spot checks on iron loss batches, only the smelting results of the corresponding batches of all the main iron loss monitoring batches are spot-checked.

[0073] The working principle and beneficial effects of the above technical solution: By analyzing and screening historical data, the iron loss batches that need to be key monitored in the current smelting week are determined. By constructing the historical weekly batch iron loss distribution data, the importance of each batch is calculated, and the main iron loss monitoring batches that need to be key inspected are screened out according to the importance, which helps to improve the pertinence and effectiveness of iron loss monitoring, reduce unnecessary repeated inspections, and thus optimize the quality management in the smelting process;

[0074] Through the analysis of historical data, batches that need to be inspected with emphasis can be selected targeted, reducing unnecessary inspections and improving work efficiency. By spot-checking the main iron loss monitoring batches, potential problems can be discovered and corrected in a timely manner to ensure product quality. By optimizing the iron loss monitoring strategy, unnecessary repeated inspections are avoided, thus reducing production costs.

[0075] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and its equivalent technologies, the present invention is also intended to include these modifications and variations.

Claims

1. A method for reducing iron loss in high-titanium slag during blast furnace smelting, characterized in that: include: The charge is mixed with raw and clinker weight ratio of 3:97, and the silicon-titanium mass ratio of the mixed charge is controlled within a preset range. During smelting, the air volume, air temperature and oxygen enrichment rate entering the furnace are controlled within a preset range, and the slag basicity, magnesium-aluminum ratio and molten iron temperature are controlled within a preset range. It also includes iron loss batch inspection, specifically: Construct historical weekly batch iron loss distribution data, and screen out all major iron loss monitoring batches of the current smelting week based on the historical weekly batch iron loss distribution data, and conduct spot checks based on the smelting results of the corresponding batches of all major iron loss monitoring batches; Build historical weekly batch iron loss distribution data including: Maintaining a raw-cooked material weight ratio of 3:97 for the charge, blast furnace smelting was carried out for several consecutive weeks, and the iron content of each batch of final smelting was collected each week. Based on the iron content of each batch of final smelting each week, the iron loss rate of each batch of each week was calculated to form historical weekly batch iron loss distribution data; Among them, the iron loss rate of each batch per week is calculated based on the final iron content of each batch per week: ;in, For the The iron loss rate of the i-th batch in the week, For the The amount of feed for the i-th batch in the week, is the mass fraction of iron in the feed, For the The iron content of the final smelted batch in week i; Based on the historical weekly batch iron loss distribution data, all major iron loss monitoring batches of the current smelting week are screened out, including: Calculate the importance of each batch: ;in, is the importance of the i-th batch, represents the number of batches with excessive iron loss rate in the i-th batch in a number of weeks, represents the maximum iron loss rate in the i-th batch in several weeks, represents the minimum iron loss rate in the i-th batch in several weeks, is the preset limit iron loss rate, is the compensation coefficient for the impact of the air volume entering the furnace, is the compensation coefficient of the furnace air temperature, is the compensation coefficient of the oxygen enrichment rate entering the furnace, is the logarithm with base e; When the importance of one of the batches is greater than the preset importance, the batch will be used as the main iron loss monitoring batch; When spot checking iron loss batches, only the smelting results of the corresponding batches of all major iron loss monitoring batches are spot checked.

2. The method for reducing iron loss in high-titanium slag during blast furnace smelting according to claim 1, characterized in that: The weight ratio of the charge is 52-55% pellets, 42-45% sintered ore and 3% green ore.

3. The method for reducing iron loss in high-titanium slag during blast furnace smelting according to claim 1, characterized in that: The mass ratio of silicon to titanium in the charge is 0.18-0.

28.

4. The method for reducing iron loss in high-titanium slag during blast furnace smelting according to claim 1, characterized in that: The preset range of the air volume during smelting is 3350-3400 / min; The preset range of the furnace air temperature is 1215-1230℃; The preset range of oxygen enrichment rate entering the furnace is 4.5-6%.

5. The method for reducing iron loss in high-titanium slag during blast furnace smelting according to claim 1, characterized in that: The preset range of slag basicity is 1.10 ± 0.05; The preset range of magnesium to aluminum ratio is 0.62-0.65; The preset range of molten iron temperature is 1420-1460℃.

6. The method for reducing iron loss in high-titanium slag during blast furnace smelting according to claim 1, characterized in that: Also includes: Control the proportion of powder with a particle size of 5 mm or less in the powder entering the furnace to be less than 2%; The smelting cycle is controlled within 6 hours; The smelting blast furnace adopts 1250 blast furnace.

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