Melt separation titanium slag modification treatment method and system

Abstract

The invention discloses a melt separation titanium slag modification treatment method and system. The method comprises the steps that in the direct reduction-melt separation process, melt separation titanium slag components are regulated and controlled to enable the melt separation titanium slag to contain 40 wt%-60 wt% of TiO2 and 1.1 wt%-9 wt% of C, deslagging is conducted, after heat preservation melting is conducted on the melt separation titanium slag at the temperature of 1550-1600 DEG C for 30-60 minutes, slow cooling is conducted to 1200 DEG C at the cooling rate of 5-10 DEG C / min, then rapid cooling is conducted to 900 DEG C at the cooling rate of 20 DEG C / min or above, finally natural cooling is conducted to the room temperature, and modified slag is obtained. According to the method, regulation and control of components of the melt-separated titanium slag are combined with heat preservation, slow cooling, quenching and natural cooling, anosovite is directionally induced to serve as a main phase of the titanium slag, micronized spinel and an amorphous glass phase, titanium resources are enriched in the anosovite phase, and the modified titanium slag high in grade and good in activity is obtained; and the problems of low additional value, small utilization scale, poor economic benefit and the like of molten titanium slag products are solved.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of metallurgy, in particular to a modified treatment method and system for smelting separation titanium slag. BACKGROUND

[0002] Vanadium-titanium magnetite has complex structure, more impurities, and close symbiotic relationship, and is difficult to comprehensively utilize. Vanadium-titanium magnetite deposits are widely distributed and have abundant reserves in China, and the proven reserves rank third in the world, but the comprehensive utilization level is low. At present, a blast furnace-converter process is mainly used to treat vanadium-titanium magnetite in China, and the process has the advantages of large production scale and high stability, but this method only realizes the recovery of iron and vanadium elements, and the titanium element is enriched in the byproduct blast furnace slag and cannot be effectively utilized. In order to ensure the smooth operation of the blast furnace, the grade of TiO2 in the blast furnace slag needs to be controlled at about 25wt%, and the low titanium grade makes it difficult to effectively utilize the blast furnace slag, and a large amount of blast furnace slag is accumulated in the yard. At present, the comprehensive utilization degree of the titanium-iron ore beneficiation, blast furnace smelting, and converter vanadium extraction process is generally: 68% for iron elements, 47% for vanadium elements, and 15% for titanium elements, and the resources are seriously wasted, and serious problems such as environmental pollution and land destruction are caused. In order to realize the efficient utilization of iron, vanadium, and titanium resources in vanadium-titanium magnetite, a direct reduction-reduction smelting method emerges as the times require.

[0003] The process of the direct reduction-smelting method is as follows: vanadium-titanium iron concentrate and the like are used as raw materials, and are prepared into pellets through crushing and balling; the pellets are directly reduced by a shaft furnace, a rotary hearth furnace and the like to obtain direct reduction pellets or direct reduced iron (DRI) and the like direct reduction products; the direct reduction products are hot-charged into a smelting furnace with carbonaceous reducing agents such as anthracite and lignite, and iron liquid and slag are melted, reduced, and separated to obtain molten iron and smelting titanium slag. Vanadium elements enter a vanadium extraction converter with the molten iron, and the vanadium is extracted in a ladle; titanium elements enter the smelting titanium slag, and subsequent resource utilization is performed.

[0004] At present, the main titanium extraction method for smelting titanium slag is "preparation of titanium dioxide by sulfuric acid method", and the method has the advantages of relatively simple process flow, but the TiO2 grade of smelting titanium slag is low (40wt%-50wt%), and there are many impurities, so the sulfuric acid method has long cycle, large acid consumption, and generates a large amount of difficult-to-utilize process byproducts, and the economic efficiency is poor, which seriously restricts the large-scale utilization of smelting titanium slag. Therefore, it is of great significance to study the modification rule of smelting titanium slag, improve its utilization value, and reduce its subsequent utilization difficulty for the large-scale industrialization of the direct reduction-reduction smelting method.

[0005] The main phases of the smelted titanium slag include CaTiO3, magnesium-aluminum spinel, black titanium, diopside, silicate and anatase, rutile, etc. The black titanium phase is mainly composed of MgTi2O5, FeTi2O5 and Ti3O5; the anatase phase and the rutile phase are mainly composed of TiO2; and the main component of the diopside phase is Ca(Mg, Fe)(SiO3)2. The subsequent utilization method of the smelted titanium slag is mainly the sulfuric acid method, so the activity of the titanium slag can also be collectively expressed as “acid solubility”. The acid solubility refers to the dissolution degree of the titanium-containing phase and other components in the slag in the acid solution. For the smelted titanium slag, the acid solubility of the black titanium phase is better than that of the perovskite phase and the rutile phase, and is much better than that of the diopside and spinel gangue phases. However, the black titanium phase only accounts for 40% to 50% of the phases of the smelted titanium slag. If too much CaO is added for slag adjustment during the smelting process, the main phase of the smelted titanium slag is the perovskite phase. The theoretical content of TiO2 in the perovskite phase is the highest, which is 58%, and the density of the perovskite is similar to that of the gangue glass phase, which leads to difficulties in subsequent separation. Compared with the perovskite phase, the maximum theoretical content of TiO2 in the black titanium phase is 70% to 80%, and the specific gravity of the black titanium phase is 4.19, which is much greater than the average specific gravity of the smelted titanium slag, which is 2.8, and can be enriched by gravity separation. In summary, in terms of composition, the black titanium is considered as the main phase of the smelted titanium slag; and in terms of grain size, the black titanium phase particle size is increased and the spinel and glass phase particle size is reduced, which can maximize the enrichment of Ti element, reduce the difficulty of subsequent gravity separation, and improve the comprehensive acid solubility of the smelted titanium slag.

[0006] The existing technology has proposed a crystal phase regulation method for the titanium-containing slag. For example, patent CN101781717B discloses a titanium slag deep processing method smelted by using titanium-containing blast furnace slag and high-titanium slag as raw materials, and proposes that the titanium slag is added into an acidic oxide for heat preservation and naturally cooled to below 1100℃ to realize the enrichment of the black titanium phase. However, the patent has not studied the crystal phase regulation method of the smelted titanium slag smelted by using vanadium-titanium metallized pellets as the main raw material, and the acidic oxide added in the patent introduces more impurity components and dilutes the effective grade of the titanium slag. Patent CN107653380B discloses a method for regulating the crystal phase of the smelted titanium slag, and proposes that the smelted titanium slag is cooled at a rate of 0.1℃ / min to 20℃ / min to 1300℃ to 1500℃ to realize the enrichment of the black titanium phase. However, the patent has not studied the measures for regulating the formation of micro spinel phase, amorphous glass phase and other impurity phases. In summary, for the smelted titanium slag smelted by using vanadium-titanium metallized pellets as the main raw material, the existing technology has not proposed a process for directing the black titanium as the main phase of the titanium slag and simultaneously micro-sizing the spinel and amorphous glass phase, so as to solve the major problems of the smelted titanium slag, such as low added value, small utilization scale and poor economic benefits. SUMMARY

[0007] In view of the above-mentioned disadvantages of the prior art, the purpose of the present application is to provide a modified treatment method and system for smelted titanium slag, which can overcome the problems of low grade, low activity and difficult utilization of titanium resources in smelted titanium slag, by regulating the composition of smelted titanium slag and combining "heat preservation + slow cooling + rapid cooling + natural cooling" to directionally induce black titanium as the main phase of titanium slag, refine spinel and amorphous glass phase, and enrich titanium resources in black titanium phase, so as to obtain modified titanium slag with high grade and good activity, further shorten the process flow of subsequent titanium extraction process, reduce the three-waste yield, and improve the economic benefit.

[0008] To achieve the above-mentioned purpose and other related purposes, the present application provides a modified treatment method for smelted titanium slag, comprising the following steps: S1, in the direct reduction-smelting process, the composition of smelted titanium slag is regulated to contain 40wt%-60wt% of TiO2 and 1.1wt%-9wt% of C, and the slag is tapped, and the smelted titanium slag is heat-preserved and melted, and the heat-preservation temperature is 1550°C-1600°C; S2, after heat-preservation and melting for 30-60 minutes, slow cooling is performed at a cooling rate of 5°C / min-10°C / min; S3, when the smelted titanium slag is cooled to 1190°C-1210°C, rapid cooling is performed at a cooling rate of more than 20°C / min; S4, when the smelted titanium slag is cooled to 890°C-910°C, natural cooling is performed to room temperature, and modified slag is obtained.

[0009] Further, the step S1 comprises: in the process of treating vanadium-titanium magnetite by direct reduction-smelting method, the composition of smelted titanium slag is regulated to contain 40wt%-60wt% of TiO2 and 1.1wt%-9wt% of C, and the slag is tapped, and the smelted titanium slag is heat-preserved and melted, and the heat-preservation temperature is 1550°C-1600°C.

[0010] Further, in the step S1, a carbonaceous reducing agent is added in the direct reduction-smelting process to regulate the composition of smelted titanium slag. The carbonaceous reducing agent is selected from at least one of coke, graphite, anthracite, lignite or semicoke.

[0011] Further, the added amount x of the carbonaceous reducing agent satisfies the following condition: , wherein m is the mass of the metallized pellet, and c is the residual carbon mass of the metallized pellet.

[0012] Further, in the step S1, the component of the smelted titanium slag is regulated to include the following components: TiO2: 40wt%-60wt%, CaO: 3wt%-10wt%, MgO: 5wt%-20wt%, SiO2: 5wt%-25wt%, Al2O3: 5wt%-20wt%, C: 1.1wt%-9wt%, w(MgO) / w(Al2O3): 0.6-0.8.

[0013] Further, in the step S1, the smelted titanium slag is discharged after the liquid layer of the molten iron and the smelted titanium slag are clearly separated.

[0014] Further, in the step S2, the slow cooling is performed in the form of furnace cooling.

[0015] Further, in the step S3, the rapid cooling is performed in the form of water quenching or air quenching.

[0016] Further, in the step S4, the natural cooling is performed in the form of air cooling.

[0017] Further, the smelted titanium slag modification treatment method further includes the following steps: S5, selecting the black titanium phase from the modified slag to obtain a titanium-enriched slag mainly composed of the black titanium phase, and the content of the black titanium phase TiO2 in the titanium-enriched slag is greater than 70%.

[0018] Further, the step S5 includes: The modified slag is subjected to grinding and separation, and reselection treatment, and the black titanium phase is selected to obtain a titanium-enriched slag mainly composed of the black titanium phase, and the content of the black titanium phase TiO2 in the titanium-enriched slag is greater than 70%.

[0019] Further, the step S5 includes: The modified slag is subjected to grinding and separation treatment, and the black titanium phase is selected by using the reselection method according to the density difference to obtain a titanium-enriched slag mainly composed of the black titanium phase, and the content of the black titanium phase TiO2 in the titanium-enriched slag is greater than 70%.

[0020] The application also provides a smelted titanium slag modification treatment system, which includes a smelted unit and a smelted titanium slag treatment unit; The smelted unit includes a smelted furnace, and a first slag discharge port for discharging the smelted titanium slag is arranged on the smelted furnace. The smelted titanium slag treatment unit includes a smelted titanium slag treatment device and a stacking area. The melting separation titanium slag treatment device comprises a furnace body, a temperature control device and a cooling device; the furnace body is used for containing the melting separation titanium slag, the furnace body is provided with a slag inlet and a second slag outlet, the slag inlet is connected with the first slag outlet, and the second slag outlet is used for discharging the melting separation titanium slag; the temperature control device is used for controlling the temperature and the cooling rate of the melting separation titanium slag in the furnace body; and the cooling device is used for cooling the melting separation titanium slag discharged from the second slag outlet. The stockpiling area is used for stacking the melting separation titanium slag after the modification treatment.

[0021] Further, the straight-line distance between the first slag outlet and the slag inlet is less than or equal to 5 meters.

[0022] Further, the temperature control device comprises a heating device, a cooling device and / or a temperature measuring device; the heating device is used for slowing down the cooling rate of the melting separation titanium slag in the furnace body, the cooling device is used for accelerating the cooling rate of the melting separation titanium slag in the furnace body, and the temperature measuring device is used for detecting the temperature of the melting separation titanium slag in the furnace body.

[0023] Further, the cooling device is arranged at or near the second slag outlet to cool the discharged melting separation titanium slag at the second slag outlet.

[0024] Further, the cooling device comprises a water quenching device and / or an air quenching device.

[0025] Further, the melting separation titanium slag production and modification treatment system further comprises a grinding and separation device, which is used for grinding and separating the melting separation titanium slag after the modification treatment.

[0026] Further, the melting separation titanium slag production and modification treatment system further comprises a gravity separation device, which is used for carrying out gravity separation treatment after the grinding and separation treatment of the melting separation titanium slag after the modification treatment, and selecting black titanium ore to obtain a titanium-rich slag mainly composed of black titanium ore.

[0027] As described above, the melting separation titanium slag modification treatment method and system have the following beneficial effects: (1) The modified treatment method of the separation titanium slag provided by the application adjusts the component content of the separation titanium slag, first fully reduces and homogenizes the components of the separation titanium slag through heat preservation melting, then controls the slow cooling of the separation slag to regulate the crystallization process, enriches titanium elements in the dense black titanium stone phase, makes the black titanium stone phase the main crystallization phase of the separation slag, and increases the crystal size of the black titanium stone phase, then uses quenching methods such as water quenching and air quenching to refine the diopside phase and glass phase, improves the acid solubility of the separation titanium slag, and reduces the difficulty of using titanium elements in the separation slag, and finally cools to room temperature to obtain modified slag. The modified slag can be obtained by subsequent methods such as grinding and selecting and reselecting, and the high-grade modified slag with a TiO2 grade of more than 70% and a black titanium stone phase as the main occurrence phase. In this way, not only the problems of low titanium grade, poor acid solubility and difficult utilization of the separation titanium slag are solved, but also the utilization rate of titanium resources and the process efficiency of titanium dioxide production by the sulfuric acid method are greatly improved, and the product added value is improved. At the same time, the application is controlled by physical methods throughout the process, and TiO2 enrichment and black titanium stone grain size growth are achieved without adding chemical reagents, which is low in cost and easy to operate. The method of the application is suitable for the comprehensive utilization link of vanadium-titanium magnetite and vanadium-titanium metallized pellets, can be combined with the direct reduction and separation process, improves the utilization of waste heat and resources, has the advantages of large processing scale, simple operation, low cost, high resource recovery rate and the like.

[0028] (2) The modified treatment system of the separation titanium slag provided by the application is designed in combination with the separation furnace, the interface is compact, and the residual heat of the separation furnace can be used for heat preservation and slow cooling, so that the waste heat is used efficiently, energy is saved, and carbon emission is reduced. BRIEF DESCRIPTION OF DRAWINGS

[0029] The drawings incorporated herein and constituting a part of the specification illustrate embodiments consistent with the present application and, together with the specification, serve to explain the principles of the present application. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained from these drawings without creative labor for those skilled in the art.

[0030] In the drawings: Figure 1 The arrangement schematic diagram of the production and modified treatment system of the separation titanium slag provided by the application.

[0031] Figure 2 The scanning electron microscope picture of the modified slag obtained in Example 1 of the application.

[0032] Figure 3 The scanning electron microscope picture of the modified slag obtained in Example 2 of the application.

[0033] Figure 4 The scanning electron microscope picture of the modified slag obtained in Comparative Example 1 of the application.

[0034] The reference signs are as follows: melting separation furnace 1, first slag outlet 2, furnace body 3, slag inlet 4, second slag outlet 5, heating device 6, cooling device 7, temperature measuring device 8, cooling equipment 9. DETAILED DESCRIPTION

[0035] The present application also can be implemented or applied by other different specific embodiments, and the details in the specification can be modified or changed based on different views and applications without departing from the spirit of the present application. The following embodiments and features in the embodiments can be combined with each other without conflict.

[0036] In the present application, the term "a plurality of" means two or more, unless otherwise specified.

[0037] The character " / " represents an "or" relationship between the front and rear objects. For example, A / B means: A or B.

[0038] The term "and / or" is a description of the relationship between the objects, which means that there can be three relationships. For example, A and / or B means: A or B, or, A and B, three relationships.

[0039] It should be noted that the drawings provided in the following embodiments only schematically illustrate the basic concept of the present application, and the drawings only show the components related to the present application, not the number, shape and size of the components when actually implemented. The actual implementation of each component may be a random change, and the component layout pattern may be more complex.

[0040] An embodiment of the present application provides a modified treatment method of melting separation titanium slag, comprising the following steps: S1, in the direct reduction-melting separation process, the components of the melting separation titanium slag are controlled to contain 40wt%-60wt% of TiO2 and 1.1wt%-9wt% of C, the slag is discharged, and the melting separation titanium slag is heat-insulated and melted, and the heat-insulation temperature is 1550°C-1600°C; S2, after heat-insulated melting for 30-60 minutes, the slow cooling is performed at a cooling rate of 5°C / min-10°C / min; S3, when the melting separation titanium slag is cooled to 1190°C-1210°C, the rapid cooling is performed at a cooling rate of more than 20°C / min; S4, when the melting separation titanium slag is cooled to 890°C-910°C, the natural cooling is performed to room temperature, and the modified slag is obtained.

[0041] The above embodiment can make the black titanium diamond as the main phase of the modified slag by regulating the composition of the smelted titanium slag and combining the heat preservation, slow cooling, rapid cooling and natural cooling, and can refine the spinel and amorphous glass phase, enrich the titanium resource in the black titanium diamond phase, obtain the modified slag with high grade and good activity, further shorten the process flow of the subsequent titanium extraction process, reduce the three waste production, and improve the economic benefit.

[0042] If the C content in the smelted titanium slag is too low, the proportion of the black titanium diamond phase in the modified slag will be small, and the average particle size will be small. If the C content in the smelted titanium slag is too high, the viscosity of the titanium slag will be too high, and the separation effect of the slag and iron will be affected.

[0043] The smelted titanium slag is kept at 1550-1600 ℃ for 30-60 minutes. On the one hand, the residual heat of the smelted titanium slag can be fully utilized to reduce the smelted titanium slag, homogenize the composition of the smelted titanium slag, increase the proportion and average particle size of the black titanium diamond phase in the modified slag. On the other hand, the modified slag can be prevented from containing other titanium-rich phases such as perovskite.

[0044] After the heat preservation and smelting, the modified slag is slowly cooled to 1200 ℃. In this temperature range, the black titanium diamond phase is precipitated. At the same time, the modified slag is slowly cooled at a cooling rate of 5-10 ℃ / min. The smelted slag can be controlled to precipitate, the titanium element can be enriched in the dense black titanium diamond phase, the black titanium diamond phase can be the main precipitated phase of the smelted slag, and the crystal size of the black titanium diamond phase can be increased. If the cooling rate is too fast, the black titanium diamond phase formed is not dense enough, the crystal size is small, and part of the black titanium diamond phase cannot be precipitated. If the cooling rate is too slow, the smelting period will be affected.

[0045] After the slow cooling, the smelted titanium slag is rapidly cooled at a cooling rate of ≥20 ℃ / min. The smelted titanium slag can make the spinel phase, diopside phase and amorphous glass phase and other impurity phases quickly precipitate, refine the crystal size, improve the acid solubility of the smelted titanium slag, and reduce the difficulty of using the titanium element in the smelted slag.

[0046] In some embodiments of the present application, the step S1 comprises: in the process of treating vanadium-titanium magnetite by direct reduction-smelting, the composition of the smelted titanium slag is regulated to contain 40wt%-60wt% of TiO2 and 1.1wt%-9wt% of C, the slag is discharged, and the smelted titanium slag is heat preserved and smelted at a heat preservation temperature of 1550-1600 ℃.

[0047] In some embodiments of the present application, in the step S1, a carbonaceous reducing agent is added in the direct reduction-smelting process to regulate the composition of the smelted titanium slag. The carbonaceous reducing agent includes but is not limited to coke, graphite, anthracite, lignite or semicoke, etc. Further, in order to control the composition of the smelted titanium slag, in some embodiments of the present application, the addition amount x of the carbonaceous reducing agent satisfies the following condition: Wherein, m is the mass of the metallized pellets, and c is the mass of residual carbon in the metallized pellets. The metallized pellets are metallized pellets prepared by direct reduction of vanadium-titanium magnetite, i.e., vanadium-titanium metallized pellets, which contain a certain amount of C elements, and therefore c refers to the content of C elements in the vanadium-titanium metallized pellets added during smelting.

[0048] In some embodiments of the present application, in step S1, the components of the smelted titanium slag are regulated to include the following components: TiO2: 40wt%-60wt%, CaO: 3wt%-10wt%, MgO: 5wt%-20wt%, SiO2: 5wt%-25wt%, Al2O3: 5wt%-20wt%, C: 1.1wt%-9wt%, w(MgO) / w(Al2O3): 0.6-0.8. Among them, MgO can improve the stability of the black titanite crystalline phase, but excessive MgO content will form a large amount of magnesium aluminate spinel and precipitate; excessive CaO content can form a perovskite phase, making the separation and beneficiation process complicated; Al2O3, as an amphoteric oxide, needs to be kept within a reasonable range, and its content is too low, which will affect the generation of black titanite phase, and if its content is too high, a large amount of magnesium aluminate spinel will be formed and precipitated; SiO2 is an impurity component, and its content needs to be reduced to avoid the formation of silicate impurity phase. Further, in some embodiments of the present application, the components of the smelted titanium slag further include FeO, Ti2O3, Cr2O3, CrO2, V2O5, V2O3, VO, etc., but are not limited thereto.

[0049] In some embodiments of the present application, in step S1, the smelted titanium slag is discharged after the liquid layer of molten iron is clearly separated from the smelted titanium slag. After the smelted titanium slag and the smelted molten iron form a stable slag-iron interface, the slag-iron reaction is in equilibrium, and a good separation interface is obtained, which can reduce the phenomena of slag entrainment and iron entrainment, and improve the recovery rate of valuable elements such as iron, vanadium and titanium in the slag-iron separation process.

[0050] In some embodiments of the present application, in step S2, the slow cooling is performed in the form of furnace cooling, i.e., after the smelted titanium slag is discharged from the smelting furnace, it is transferred to another furnace body for slow cooling.

[0051] In some embodiments of the present application, in step S3, when the smelted titanium slag is cooled to 1195°C-1205°C, it is rapidly cooled at a cooling rate of 20°C / min or higher. The rapid cooling method includes but is not limited to water quenching and air quenching. The water used in water quenching includes but is not limited to industrial circulating water, reclaimed water, tap water, etc.

[0052] In some embodiments of the present application, in step S4, when the smelted titanium slag is cooled to 895°C-905°C, it is naturally cooled to room temperature to obtain a modified slag. The natural cooling method includes but is not limited to air cooling.

[0053] In some embodiments of the present application, the modified treatment method of the smelted titanium slag further comprises the following steps: S5, selecting the leucoxene phase from the modified slag to obtain a leucoxene phase-based enriched titanium slag, wherein the leucoxene phase TiO2 content in the enriched titanium slag is greater than 70%. In an exemplary embodiment, the modified slag is subjected to grinding and separation treatment, and then the leucoxene phase is selected by gravity separation according to the density difference to obtain a leucoxene phase-based enriched titanium slag.

[0054] Please refer to Figure 1 , Figure 1 The smelted titanium slag modification treatment system provided for an embodiment of the present application, as shown in Figure 1 , comprises a smelting unit and a smelted titanium slag treatment unit; the smelting unit comprises a smelting furnace 1, for example a smelting electric furnace, and a first slag outlet 2 provided on the smelting furnace 1 for discharging smelted titanium slag; the smelted titanium slag treatment unit comprises a smelted titanium slag treatment device and a storage area; the smelted titanium slag treatment device comprises a furnace body 3, a temperature control device and a cooling device 9; the furnace body 3 is used to hold smelted titanium slag, and the furnace body 3 is provided with a slag inlet 4 and a second slag outlet 5, the slag inlet 4 is connected with the first slag outlet 2, and the second slag outlet 5 is used to discharge smelted titanium slag; the temperature control device is used to control the temperature and cooling rate of the smelted titanium slag in the furnace body 3; the cooling device 9 is used to cool the smelted titanium slag discharged from the second slag outlet 5; and the storage area is used to store the modified smelted titanium slag (not shown in the figure).

[0055] The process of modifying the smelted titanium slag by using the smelted titanium slag modification treatment system according to the method provided in the above embodiments comprises: in the smelting reduction process of the smelting furnace 1, adding a carbonaceous reducing agent to regulate the components of the smelted titanium slag; the smelted titanium slag flows into the furnace body 3 through the first slag outlet 2 and the slag inlet 4, and is subjected to heat preservation and melting; then the temperature control device is used to control the cooling rate of the smelted titanium slag, and the smelted titanium slag is subjected to slow cooling; after the slow cooling is completed, the smelted titanium slag is discharged from the second slag outlet 5 and is subjected to rapid cooling at the second slag outlet 5; and finally, the smelted titanium slag is transferred to the storage area for air cooling to room temperature to obtain modified slag. In this system, the smelted titanium slag treatment device and the smelting furnace 1 are designed in a compact interface and have a large processing scale, and can utilize the residual heat of the smelted electric furnace for heat preservation and slow cooling, thereby saving energy.

[0056] In some embodiments of the present application, the straight-line distance between the first slag outlet 2 and the slag inlet 4 is less than or equal to 5 meters, so that the smelted titanium slag treatment device and the smelting furnace 1 are compactly coupled, the residual heat of the titanium slag can be fully utilized for heat preservation, and the components of the smelted titanium slag can be homogenized.

[0057] In some embodiments of the present application, the temperature control device includes a heating device 6, a cooling device 7 and / or a temperature measuring device 8. The heating device 6 is used to slow down the cooling rate of the molten separation titanium slag in the furnace body 3, for example, a heating electrode can be used; the cooling device 7 is used to accelerate the cooling rate of the molten separation titanium slag in the furnace body 3, for example, an air blower can be used; the temperature measuring device 8 is used to detect the temperature of the molten separation titanium slag in the furnace body 3, for example, a temperature sensor can be used.

[0058] In some embodiments of the present application, the cooling device 9 is arranged at or near the second slag outlet 5 to cool the discharged molten separation titanium slag at the second slag outlet 5. The cooling device 9 includes but is not limited to a water quenching device, an air quenching device, etc.

[0059] In some embodiments of the present application, the molten separation titanium slag production and modification treatment system further comprises a grinding and sorting device (not shown in the figure), which is used for grinding and sorting treatment of the molten separation titanium slag after modification treatment.

[0060] In some embodiments of the present application, the molten separation titanium slag production and modification treatment system further comprises a gravity separation device (not shown in the figure), which is used for gravity separation treatment after the molten separation titanium slag after modification treatment has been subjected to grinding and sorting treatment, and selects black titanium ore phase to obtain enriched titanium slag mainly in black titanium ore phase.

[0061] The following specific examples are used to illustrate the present application in detail. It should also be understood that the following examples are only used to illustrate the present application in detail, and cannot be understood as limiting the scope of protection of the present application. Some non-essential improvements and adjustments made by those skilled in the art based on the above content of the present application are within the scope of protection of the present application. The following examples of specific process parameters are only one example in the appropriate range, i.e. those skilled in the art can select within the appropriate range according to the description herein, and are not limited to the specific values of the following examples.

[0062] Example 1 1) In the reduction and separation process of the melting separation electric furnace, coke reducing agent is added to control the composition of the molten separation titanium slag: TiO2: 56%, CaO: 5wt%, MgO: 8wt%, SiO2: 13.5wt%, Al2O3: 10wt%, FeO: 4wt%, C: 3.5wt%.

[0063] 2) At the end of the reduction and separation process of the vanadium-titanium metallized pellet, the molten separation titanium slag and the molten iron liquid layer are clearly separated.

[0064] 3) The molten separation titanium slag flows into the molten separation titanium slag treatment device through the first slag outlet 2 for heat preservation melting, and is controlled at 1550°C for 60 minutes. Subsequently, the molten separation titanium slag is slowly cooled to 1200°C at a cooling rate of 6°C / min in the form of furnace cooling, and is discharged and air quenched at the second slag outlet 5 to ensure a cooling rate greater than 20°C / min.

[0065] 4) When the temperature of the molten separation titanium slag is less than 900°C, the modified slag is obtained by stacking and air cooling to room temperature. The phase composition of the modified slag is observed by using a scanning electron microscope, as shown in FIG. 4, the slag contains black titanium stone phase, glass phase, and magnesium-aluminum spinel phase. The modified slag structure is dense, and the average particle size of the black titanium stone phase in the slag is 63 microns. Figure 2

[0066] 5) The modified slag is subjected to grinding and separation treatment, and the black titanium stone phase is selected by using gravity separation method according to the density difference to obtain the enriched titanium slag. The TiO2 content of the black titanium stone phase in the enriched titanium slag is 78%.

[0067] Example 2 1) In the reduction and molten separation process of the molten separation electric furnace, the anthracite coal powder reducing agent is added to control the components of the molten separation titanium slag: TiO2: 54%, CaO: 8wt%, MgO: 6.5wt%, SiO2: 14.5wt%, Al2O3: 9wt%, FeO: 1.5wt%, and C: 6.5wt%.

[0068] 2) The molten separation titanium slag is clearly layered with the molten iron liquid surface at the end of the reduction and molten separation process of the vanadium-titanium metallized pellet.

[0069] 3) The molten separation titanium slag flows into the molten separation titanium slag treatment device through the first slag outlet 2 for heat preservation melting, and is controlled at 1550°C for 60 minutes. Subsequently, the molten separation titanium slag is slowly cooled to 1200°C at a cooling rate of 10°C / min in the form of furnace cooling, and is discharged and air quenched at the second slag outlet 5 to ensure a cooling rate greater than 20°C / min.

[0070] 4) When the temperature of the molten separation titanium slag is less than 900°C, the modified slag is obtained by stacking and air cooling to room temperature. The phase composition of the modified slag is observed by using a scanning electron microscope, as shown in FIG. 4, the slag contains black titanium stone phase, glass phase, and magnesium-aluminum spinel phase. The modified slag structure is dense, and the average particle size of the black titanium stone phase in the slag is 63 microns. Figure 3

[0071] 5) The modified slag is subjected to grinding and separation treatment, and the black titanium stone phase is selected by using gravity separation method according to the density difference to obtain the enriched titanium slag. The TiO2 content of the black titanium stone phase in the enriched titanium slag is 78%.

[0072] Comparative Example 1 ​​1) In the reduction and separation process of the electric furnace, add anthracite coal powder reducing agent to control the composition of the separation titanium slag: TiO2: 59%, CaO: 6wt%, MgO: 5wt%, SiO2: 15wt%, Al2O3: 6wt%, FeO: 8wt%, C:1.0wt%.

[0073] 2) At the end of the reduction and separation process of the vanadium-titanium metallized pellets, the separation titanium slag and the molten iron liquid surface are clearly layered.

[0074] 3) The separation titanium slag flows into the separation titanium slag treatment device through the first slag outlet 2 for heat preservation and melting, and is controlled at 1550℃ for 20 minutes, and then the separation titanium slag is controlled to be cooled in the form of furnace cooling at a cooling rate of 6℃ / min to 1200℃, and then is discharged and air quenched at the second slag outlet 5 to ensure a cooling rate greater than 20℃ / min.

[0075] 4) When the temperature of the separation titanium slag is less than 900℃, the modified slag is obtained by stacking and air cooling to room temperature, and the phase composition of the modified slag is observed by using a scanning electron microscope, as shown in Figure 4 , the slag contains black titanium stone phase, glass phase, and magnesium-aluminum spinel phase. Due to the small amount of carbon added, the proportion of black titanium stone phase in the modified slag is small, and the average particle size of the black titanium stone phase in the modified slag is 35 microns.

[0076] Comparative Example 2 1) In the reduction and separation process of the electric furnace, add anthracite coal powder reducing agent to control the composition of the separation titanium slag: TiO2: 52%, CaO: 10wt%, MgO: 6wt%, SiO2: 15wt%, Al2O3: 9wt%, FeO: 4.5wt%, C:3.5wt%.

[0077] 2) At the end of the reduction and separation process of the vanadium-titanium metallized pellets, the separation titanium slag and the molten iron liquid surface are clearly layered.

[0078] 3) The separation titanium slag flows into the separation titanium slag treatment device through the first slag outlet 2 for heat preservation and melting, and is controlled at 1550℃ for 20 minutes, and then the separation titanium slag is controlled to be cooled in the form of furnace cooling at a cooling rate of 6℃ / min to 1200℃, and then is discharged and air quenched at the second slag outlet 5 to ensure a cooling rate greater than 20℃ / min.

[0079] 4) When the temperature of the separation titanium slag is less than 900℃, the modified slag is obtained by stacking and air cooling to room temperature, and the phase composition of the modified slag is observed by using a scanning electron microscope, as shown in

[0080] Comparative Example 3 1) In the process of reduction and separation in the electric furnace, coke is added as a reducing agent to control the composition of the separation titanium slag: TiO2: 54%, CaO: 6wt%, MgO: 7wt%, SiO2: 13.5wt%, Al2O3: 11wt%, FeO: 5wt%, C: 3.5wt%.

[0081] 2) At the end of the reduction and separation process of vanadium-titanium metallized pellets, the separation titanium slag and molten iron are clearly layered.

[0082] 3) The separation titanium slag flows into the separation titanium slag treatment device through the first slag outlet 2 for heat preservation and melting, and is controlled at 1550℃ for 60 minutes, and then the separation titanium slag is controlled to be cooled to 900℃ at a cooling rate of 6℃ / min in the form of furnace cooling, and then the slag is discharged.

[0083] 4) The modified slag is obtained by air cooling to room temperature after discharging and stacking, and the phase composition of the modified slag is observed by scanning electron microscope. The modified slag contains three phases of black titanium stone phase, glass phase and magnesium aluminum spinel phase, and the average particle size of the black titanium stone phase in the slag is 58 microns. At the same time, the grain size of the spinel phase, glass phase and other impurity phases is large, and it is difficult to separate the black titanium stone phase by gravity separation after the modified slag is ground and separated.

[0084] Table 1 Modification indexes of separation titanium slag under different control modes

[0085] The above examples are only illustrative of the principles and effects of the present application, and are not intended to limit the present application. Any person skilled in the art can modify or change the above examples without departing from the spirit and scope of the present application. Therefore, all equivalent modifications or changes made by those skilled in the art without departing from the spirit and technical idea disclosed in the present application should be covered by the claims of the present application.

Claims

1. A method for modifying treatment of a titania slag, characterized by, The method comprises the following steps: S1. In the direct reduction-melting separation process, the component of the melting separation titanium slag is regulated to contain 40wt%-60wt% of TiO2 and 1.1wt%-9wt% of C, and the slag is tapped, and the melting separation titanium slag is kept at a temperature of 1550°C-1600°C; S2. After the keeping melting for 30-60 minutes, the slow cooling is performed at a cooling rate of 5°C / min-10°C / min; S3. When the melting separation titanium slag is cooled to 1190°C-1210°C, the rapid cooling is performed at a cooling rate of more than 20°C / min; S4. When the melting separation titanium slag is cooled to 890°C-910°C, the natural cooling is performed to room temperature, and the modified slag is obtained.

2. The method of claim 1, wherein: In the step S1, in the process of treating vanadium-titanium magnetite by the direct reduction-melting separation method, the component of the melting separation titanium slag is regulated to contain 40wt%-60wt% of TiO2 and 1.1wt%-9wt% of C, and the slag is tapped, and the melting separation titanium slag is kept at a temperature of 1550°C-1600°C. In the step S1, the component of the melting separation titanium slag is regulated to contain the following components: TiO2: 40wt%-60wt%, CaO: 3wt%-10wt%, MgO: 5wt%-20wt%, SiO2: 5wt%-25wt%, Al2O3: 5wt%-20wt%, C: 1.1wt%-9wt%, w(MgO) / w(Al2O3): 0.6-0.

8. In the step S1, the melting separation titanium slag is tapped after the liquid layer of the molten iron is clearly separated from the melting separation titanium slag.

3. The method of claim 1, wherein: In the step S1, in the direct reduction-melting separation process, the carbonaceous reducing agent is added to regulate the component of the melting separation titanium slag.

4. The method of claim 3, wherein: The amount x of the carbonaceous reducing agent added satisfies the following condition: wherein m is the mass of the metallized pellets and c is the residual carbon mass of the metallized pellets.

5. The method of claim 1, wherein: In the step S2, the slow cooling is performed in the form of furnace cooling. In the step S3, the rapid cooling is performed in the form of water quenching or air quenching. In the step S4, the natural cooling is performed in the form of air cooling.

6. The method of claim 1, wherein, The method for modifying the melting separation titanium slag further comprises the following step: S5. The black titanic stone phase is selected from the modified slag, and a titanium-rich slag mainly containing the black titanic stone phase is obtained, and the content of the black titanic stone phase TiO2 in the titanium-rich slag is greater than 70%.

7. The method of claim 1, wherein, The step S5 comprises: The modified slag is ground and selected, and the black titanic stone phase is selected, and a titanium-rich slag mainly containing the black titanic stone phase is obtained, and the content of the black titanic stone phase TiO2 in the titanium-rich slag is greater than 70%.

8. The modified treatment system of slag of kiln separation of titanium according to claim 1, characterized by, The melting separation unit and the melting separation titanium slag treatment unit are provided. The melting separation unit comprises a melting separation furnace, and a first slag tapping opening for tapping the melting separation titanium slag is arranged on the melting separation furnace. The melting separation titanium slag treatment unit comprises a melting separation titanium slag treatment device and a stacking area. The melting separation titanium slag treatment device comprises a furnace body, a temperature control device and a cooling device, the furnace body is used for containing the melting separation titanium slag, a slag inlet and a second slag tapping opening are arranged on the furnace body, the slag inlet is connected with the first slag tapping opening, and the second slag tapping opening is used for tapping the melting separation titanium slag; the temperature control device is used for controlling the temperature and the cooling rate of the melting separation titanium slag in the furnace body; and the cooling device is used for cooling the melting separation titanium slag tapped from the second slag tapping opening. The stacking area is used for stacking the modified melting separation titanium slag.

9. The system of claim 8, wherein: A straight-line distance between the first slag outlet and the second slag outlet is less than or equal to 5 meters; And / or, the temperature control device comprises a heating device, a cooling device and / or a temperature measuring device, the heating device is used to slow down a cooling rate of the molten separation titanium slag in the furnace body, the cooling device is used to accelerate the cooling rate of the molten separation titanium slag in the furnace body, and the temperature measuring device is used to detect a temperature of the molten separation titanium slag in the furnace body; And / or, the cooling device is arranged at or near the second slag outlet. And / or, the cooling device comprises a water quenching device and / or an air quenching device.

10. The system of claim 8, wherein: The molten separation titanium slag production and modification treatment system further comprises a grinding and separation device, which is used to perform grinding and separation treatment on the modified molten separation titanium slag. And / or, the molten separation titanium slag production and modification treatment system comprises a gravity separation device, which is used to perform gravity separation treatment on the modified molten separation titanium slag after the grinding and separation treatment, and select black titanium ore to obtain enriched titanium slag mainly in the form of black titanium ore.

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