Sintering method of high-titanium vanadium-titanium magnetite concentrate

Abstract

The invention provides a sintering method of high-titanium vanadium-titanium magnetite concentrate, and relates to the technical field of sintering. Comprising the steps that S1, a sintering mixture is evenly distributed on a sintering machine trolley; s2, igniting the sintering mixture distributed on the trolley by an igniter, punching a sintering material surface after sintering ignition, and then spraying steam to the material surface; s3, the material layer is sintered, and after the sintering process of the material layer is completed, the mixture is solidified into sintered ore; according to the method, the sintering material surface is punched after sintering ignition, airflow resistance is reduced, meanwhile, oxygen-enriched steam is sprayed on the material surface, heat exchange is increased, the oxygen content in the sintering process is increased, carbon particles are promoted to be rapidly combusted, the front moving speed of flames is increased, the front moving speed of the flames is matched with the moving speed of heat waves, at the moment, the sintering speed is fastest, and the service life of the flames is prolonged. The sintering temperature is higher, so that the purpose of high-yield and high-quality sintering is achieved.

Description

Technical Field

[0001] The present application relates to the field of sintering technology, and in particular to a sintering method for high-titanium vanadium-titanium magnetite concentrate. Background Art

[0002] High-titanium vanadium-titanium magnetite concentrate is the main mineral resource in Panzhihua-Xichang area, and the resources are rich. Vanadium-titanium magnetite concentrate has special physical and chemical properties, and its sintering performance is also very special.

[0003] The liquid phase of high-titanium vanadium-titanium sinter has high AlO3 and MgO contents, high melting point, high viscosity, poor fluidity and high melting point. In order to produce enough liquid phase that can flow, the sintering temperature must be increased. However, as the sintering reducing atmosphere increases, the proportion of perovskite in the sintered mineral structure increases, the strength of the sintered ore decreases, and the material layer has poor air permeability, the sintering material layer is thin, the return ore ratio is high, and the process energy consumption will also be high. At the same time, its sintering utilization coefficient is low, and the titanium magnet concentrate is generally 30% to 60% -0.074mm, and its surface area is about 700cm 2 / g, poor water absorption, poor balling, poor air permeability of the material layer, slow vertical sintering speed, reduced sintering output, and low utilization coefficient; In addition, the FeO of high-titanium vanadium-titanium magnetite concentrate is high (28% to 32%). During the sintering process, the titanium magnetite is oxidized to form titanium hematite, which consumes more oxygen. According to theoretical calculations, sintering per ton of high-titanium vanadium-titanium magnetite concentrate consumes 39m more oxygen than ordinary concentrate. 3 Air, if the excess air coefficient and air leakage rate are taken into account, the unit air consumption is about 150m 3 .

[0004] In view of this, the present application aims to provide a sintering method for high-titanium vanadium-titanium magnetite concentrate to improve the quality indicators of the sintered ore. Summary of the invention

[0005] The purpose of the embodiments of the present application is to provide a sintering method for high-titanium vanadium-titanium magnetite concentrate, which can solve the technical problem of sintering performance of high-titanium vanadium-titanium magnetite concentrate.

[0006] The present application provides a sintering method for high-titanium vanadium-titanium magnetite concentrate, comprising the following steps:

[0007] S1. Evenly distribute the sintering mixture on the sintering machine trolley;

[0008] S2, igniting the sintering mixture on the trolley by an igniter, and drilling holes on the sintering material surface after sintering and ignition, and then spraying steam on the material surface;

[0009] S3, the material layer is sintered, and after the sintering process of the material layer is completed, the mixed material is consolidated into sintered ore.

[0010] Furthermore, in step S2, a roller structure with push rods distributed on the surface of the sintering material is rolled on the surface of the sintering material to punch holes with a hole depth of 2-3 cm and a hole diameter of 1.5-1.8 cm.

[0011] Furthermore, in step S2, a plurality of top rods are evenly distributed in an array on the surface of the roller structure, and the distance between two adjacent top rods does not exceed 8 cm.

[0012] Furthermore, in step S2, the mandrel is welded on the surface of the roller structure, and the length of the mandrel does not exceed 4 cm.

[0013] Further, in step S2, the push rod has a tapered tip.

[0014] Furthermore, in step S2, the steam sprayed onto the material surface is oxygen-enriched steam, the steam temperature is 180-200°C, the steam pressure is 300 kPa, and the oxygen enrichment range is 20% to 40%.

[0015] Furthermore, in step S2, steam is sprayed toward the material surface through a plurality of rows of steam pipes spaced apart along the moving direction of the material layer.

[0016] Furthermore, in step S2, a plurality of high-pressure nozzles are evenly spaced apart on each row of steam pipes, and the high-pressure nozzles on two adjacent rows of steam pipes are staggered.

[0017] Furthermore, in step S2, each row of the jet pipes is connected to an oxygen-enriched pipe, and control valves are provided on the jet pipes and the oxygen-enriched channels, respectively.

[0018] Furthermore, in step S3, during the sintering process of the material layer, a negative pressure exhaust structure is provided to continuously extract the gas and products generated by the combustion, thereby providing necessary oxygen for the sintering process and discharging waste gas.

[0019] Beneficial effects of the present invention:

[0020] The sintering method of high-titanium vanadium-titanium magnetite concentrate provided by the present invention comprises the following steps: S1, evenly distributing the sintering mixture on the sintering machine trolley; S2, igniting the sintering mixture distributed on the trolley by an igniter, and drilling holes on the sintering material surface after sintering and igniting, and then spraying steam on the material surface; S3, sintering the material layer, and consolidating the mixture into sintered ore after the material layer completes the sintering process; the present invention is beneficial to reducing airflow resistance by drilling holes on the sintering material surface after sintering and igniting, so that the air permeability of the sintering process is improved, and after the material surface is drilled, the The process cracks caused by thermal stress in the surface sintered ore lead to uneven airflow distribution. At the same time, the present application increases heat exchange and improves the terminal temperature level by spraying oxygen-rich steam on the material surface, slowing down the cooling rate of the material layer, reducing thermal stress and cracks. At the same time, oxygen-rich steam is sprayed, which increases the oxygen content in the sintering process and promotes rapid combustion of carbon particles, thereby accelerating the movement speed of the flame front to match the movement speed of the heat wave. At this time, the sintering speed is the fastest and the sintering temperature is also higher, thereby achieving the purpose of high-yield and high-quality sintering. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0022] Figure 1 It is a test diagram of oxygen content and sintering time in an embodiment of the present invention;

[0023] Figure 2 It is a schematic diagram of the roller structure in the embodiment of the present invention punching holes on the sintering material surface;

[0024] Figure 3 It is a schematic diagram of the steam pipeline in an embodiment of the present invention spraying oxygen-enriched steam on the sintering material surface. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations.

[0026] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for which protection is sought, but merely represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0027] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0028] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, or the positions or positional relationships in which the product of the application is usually placed when in use. They are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0029] In addition, the terms "horizontal", "vertical", "overhanging" and the like do not mean that the components are required to be absolutely horizontal or overhanging, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0030] In the description of this application, it should also be noted that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0031] See also Figure 1-Figure 3 As shown, this embodiment provides a sintering method for high-titanium vanadium-titanium magnetite concentrate, comprising the following steps:

[0032] S1. Evenly distribute the sintering mixture on the sintering machine trolley;

[0033] S2, igniting the sintering mixture on the trolley by an igniter, and drilling holes on the sintering material surface after sintering and ignition, and then spraying steam on the material surface;

[0034] S3, the material layer is sintered, and after the sintering process of the material layer is completed, the mixed material is consolidated into sintered ore.

[0035] In step S2, a roller structure with push rods distributed on the surface of the sintering material is rolled on the surface of the sintering material to punch holes in the surface of the sintering material, with a hole depth of 2-3 cm and a hole diameter of 1.5-1.8 cm.

[0036] Among them, in step S2, a plurality of top rods are evenly distributed in an array on the surface of the roller structure, and the spacing between two adjacent rows of top rods is set to 8 cm, and the spacing between the top rods in the same row is set to 6 cm, so as to achieve better perforation air permeability.

[0037] Wherein, in step S2, the mandrel is welded on the surface of the roller structure, and the length of the mandrel is set to 4 cm, and a conical tip is set on the mandrel to achieve stable drilling and control of the drilling depth.

[0038] Wherein, in step S2, the steam sprayed onto the material surface is oxygen-enriched steam, the steam temperature is 180-200°C, the steam pressure is 300 kPa, and the oxygen-enriched range is 21%.

[0039] Wherein, in step S2, steam is sprayed toward the material surface through a plurality of rows of steam pipes spaced apart along the moving direction of the material layer.

[0040] Among them, in step S2, a plurality of high-pressure nozzles are evenly spaced on each row of steam pipes, and the high-pressure nozzles on two adjacent rows of steam pipes are staggered to achieve steam injection of the entire material layer and avoid injection dead corners.

[0041] Among them, in step S2, each row of jet pipes is connected to an oxygen-enriched pipe, and control valves are respectively provided in the jet pipes and the oxygen-enriched channel. The control valves are mainly used to control the opening and closing of the steam and oxygen-enriched pipes, and regulate the oxygen-enriched range.

[0042] Among them, in step S3, during the sintering process of the material layer, a negative pressure exhaust structure is provided to continuously extract the gas and products generated by the combustion, thereby providing necessary oxygen for the sintering process and discharging waste gas.

[0043] The same sintering method as in the above embodiment is used, only the oxygen content in the steam in other embodiments is set to 23%, 24%, 25% and 26% respectively, and the mineral composition of the sintered ore is tested. The test results are shown in Table 1 below:

[0044] Table 1: Changes in mineral composition of sintered ore

[0045]

[0046] The same sintering method as in the above embodiment is used, except that the oxygen content in the steam in other embodiments is set to 21%, 35%, 43%, 50% and 58% respectively, and the oxygen content in the exhaust gas, the vertical sintering speed and the productivity during the sintering process are tested. The test results are shown in Table 2 below:

[0047] Table 2: Sintering process test table

[0048] Oxygen content in steam % Oxygen content in exhaust gas % <![CDATA[Vertical sintering speed mm / min -1 > productivity% 21 8 28.8 100 35 9.52 31.65 113 43 11.85 34.83 121 50 14.43 39.59 130 58 16.84 40.55 140

[0049] As shown in Table 2 above, when the oxygen content reaches 43%, the vertical sintering speed increases by 21% and the output increases by 21%. The reason why the output increase is greater than the vertical sintering speed increase is that the oxygen content in the air increases, the sintering process improves, and the yield rate increases.

[0050] In addition, the changes in oxygen content and sintering time during the sintering process in the above embodiment were tested, and the test results are shown in Figure 1 shown.

[0051] It can be seen that with the increase of oxygen content in the air, CO2 / CO in the exhaust gas increases, indicating that the oxidation reaction of carbon is more complete and the utilization rate of carbon in sintering is improved. At the same time, it can be seen that under the constant negative pressure of exhaust, the time to reach the highest point of exhaust gas temperature is shortened, indicating that the sintering speed is accelerated. In the oxygen enrichment range of 20% to 40%, the sintering ore yield, sintering machine productivity and sintering ore strength all increase rapidly with the increase of oxygen enrichment; when the oxygen enrichment rate exceeds 40%, the yield rate does not change much if the oxygen enrichment rate is further increased, but the productivity and sintering ore strength continue to increase.

[0052] In this embodiment, the injection of oxygen-enriched steam within a reasonable range improves the sintering yield and mechanical strength for the following reasons:

[0053] (1) As the amount of exhaust gas decreases and the combustion temperature increases, the amount of liquid phase generated increases, and the amount of bonding phase increases;

[0054] (2) The amount of waste gas is reduced, the cooling rate is slowed down, and the degree of mineral crystallization is improved;

[0055] (3) The cooling rate slows down, resulting in less thermal stress and less cracks;

[0056] (4) Due to the increase of strong minerals 2CaO.Fe2O3 and 3CaO.FeO.7Fe2O3, the glass phase decreases (see Table 1 above); in addition, due to the decrease of FeO in the sintered ore and the increase of Fe2O3, the reducibility is improved. At the same time, the enhancement of the oxidizing atmosphere during the sintering process is beneficial to desulfurization and the inhibition of alkali metal volatilization.

[0057] However, as the oxygen enrichment rate increases, the reduction expansion performance of the sintered ore decreases, mainly because the amount of secondary Fe2O3 generated increases, which is converted into Fe3O4 during the reduction process, causing volume expansion and leading to thermal cracking. Therefore, in this embodiment, the oxygen content in the oxygen-enriched steam is set to 20% to 40% to better achieve sintered ore quality control.

[0058] To sum up, the sintering method of high-titanium vanadium-titanium magnetite concentrate provided in this embodiment is aimed at the sintering of special ores. By drilling holes on the sintering material surface after sintering ignition, it is beneficial to reduce air flow resistance, so that the air permeability of the sintering process is improved. After the material surface is drilled, the process cracks caused by thermal stress on the surface of the sintered ore are eliminated, which leads to uneven air flow distribution. At the same time, the present application increases heat exchange and improves the terminal temperature level by spraying oxygen-rich steam on the material surface, slows down the cooling rate of the material layer, reduces thermal stress, and reduces cracks. At the same time, oxygen-rich steam is sprayed, which increases the oxygen content in the sintering process and promotes rapid combustion of carbon particles, thereby accelerating the movement speed of the flame front to match the movement speed of the heat wave. At this time, the sintering speed is the fastest and the sintering temperature is also higher, thereby achieving the purpose of high-yield and high-quality sintering.

[0059] The above are only preferred embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A sintering method for high-titanium vanadium-titanium magnetite concentrate, characterized in that: The steps include: S1. Evenly distribute the sintering mixture on the sintering machine trolley; S2, igniting the sintering mixture on the trolley by an igniter, and drilling holes on the sintering material surface after sintering and ignition, and then spraying steam on the material surface; S3, the material layer is sintered, and after the sintering process of the material layer is completed, the mixed material is consolidated into sintered ore.

2. The sintering method of high-titanium vanadium-titanium magnetite concentrate according to claim 1, characterized in that: In step S2, a roller structure with push rods distributed on the surface of the sintering material is rolled on the surface of the sintering material to punch holes with a depth of 2-3 cm and a diameter of 1.5-1.8 cm.

3. The sintering method of high-titanium vanadium-titanium magnetite concentrate according to claim 2, characterized in that: In step S2, a plurality of top rods are evenly distributed in an array on the surface of the roller structure, and the distance between two adjacent top rods does not exceed 8 cm.

4. The sintering method of high-titanium vanadium-titanium magnetite concentrate according to claim 3, characterized in that: In step S2, the mandrel is welded on the surface of the roller structure, and the length of the mandrel does not exceed 4 cm.

5. The sintering method of high-titanium vanadium-titanium magnetite concentrate according to claim 4, characterized in that: In step S2, the ejector pin has a tapered tip.

6. The sintering method of high-titanium vanadium-titanium magnetite concentrate according to claim 1, characterized in that: In step S2, the steam sprayed onto the material surface is oxygen-enriched steam, the steam temperature is 180-200°C, the steam pressure is 300 kPa, and the oxygen enrichment range is 20% to 40%.

7. The sintering method of high-titanium vanadium-titanium magnetite concentrate according to claim 1, characterized in that: In step S2, steam is sprayed onto the material surface through a plurality of rows of steam pipes spaced apart along the moving direction of the material layer.

8. The sintering method of high-titanium vanadium-titanium magnetite concentrate according to claim 7, characterized in that: In step S2, a plurality of high-pressure nozzles are evenly spaced apart on each row of steam pipes, and the high-pressure nozzles on two adjacent rows of steam pipes are staggered.

9. The sintering method of high-titanium vanadium-titanium magnetite concentrate according to claim 8, characterized in that: In step S2, each row of jet pipes is connected to an oxygen-enriched pipe, and control valves are provided on the jet pipes and the oxygen-enriched channels.

10. The sintering method of high-titanium vanadium-titanium magnetite concentrate according to claim 1, characterized in that: In step S3, during the sintering process of the material layer, a negative pressure exhaust structure is provided to continuously extract the gases and products generated by the combustion, thereby providing the necessary oxygen for the sintering process and discharging waste gas.

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