Method for jointly smelting high titanium slag by adopting multiple raw materials

Abstract

The invention provides a method for jointly smelting high titanium slag by adopting multiple raw materials, which comprises the following steps: S1, adding a binder and water into electric furnace fly ash, and stirring to obtain a first fly ash block; s2, rolling, crushing and screening the first dedusting ash block to obtain a second dedusting ash block; s3, the second dedusting ash blocks are mixed into the titanium concentrate to form a first mixed material; s4, adding a reducing agent into the first mixed material to form a second mixed material; s5, the second mixture and the high-titanium slag fine powder are added into an electric furnace for combined smelting, and high-titanium slag and regenerated electric furnace fly ash are obtained; and S6, cooling, crushing and grading the high-titanium slag to obtain a high-titanium slag finished product and regenerated high-titanium slag fine powder. By means of the method, the electric furnace fly ash and the high titanium slag fine powder can be fully recycled, recycling of by-products and waste products is achieved, the economic benefit of the high titanium slag is improved, meanwhile, the proportion of the regenerated high titanium slag fine powder, mine consumption and power consumption per ton slag are reduced, and the production cost of the high titanium slag is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of metallurgy, in particular to a method for jointly smelting high-titanium slag by using multiple raw materials. BACKGROUND

[0002] High-titanium slag is one of the raw materials for producing chlorination titanium dioxide. The essence of high-titanium slag production is to mix titanium concentrate with solid reducing agent and then add it into an electric furnace for reduction smelting. In this process, the oxides of iron (such as FeO and Fe2O3) in the titanium concentrate are selectively reduced into metallic iron, while the oxides of titanium (such as TiO2) are enriched in the slag, and after slag-iron separation, high-titanium slag and metallic iron are obtained. At the same time, a large amount of dust removal ash will also be produced during the production of high-titanium slag, which needs to be collected by a dust removal device and then treated. Due to the high content of impurities such as silicon and calcium in the dust removal ash and its fine particle size, the dust removal ash is generally discharged from the dust removal device and placed in a ton bag, then stacked in a warehouse for solid waste treatment.

[0003] Based on this, some researchers have explored the resource utilization of dust removal ash. Patent CN119372487A discloses a method for recycling dust removal ash from titanium slag smelting, which mixes and dries the dust removal ash with wet ore to obtain a mixture, and then smelts the mixture by controlling the feeding of the mixture, titanium concentrate and reducing agent, and power supply. However, using this method, the particle size of the dust removal ash entering the furnace is still fine, which is easy to be taken out by the dust removal fan, affecting the titanium yield. In order to solve this problem, patent CN107119198A discloses a method for recycling dust removal powder from a titanium slag electric furnace, which forms a slurry by adding water to the dust removal powder, and then combines magnetic separation and balling treatment to further dry and smelt the titanium slag, which is beneficial to large-scale treatment of dust removal ash. However, the wastewater and tailings generated in the magnetic separation process are harmful to the environment and difficult to handle.

[0004] In addition, the particle size of high-titanium slag raw material also has requirements for the production of chlorination titanium dioxide. Generally speaking, the high-titanium slag prepared after electric furnace smelting needs to be crushed and classified to obtain high-titanium slag products. In this process, 80%-90% of high-titanium slag products and 10%-20% of high-titanium slag fine powder can be obtained. However, the particle size of high-titanium slag fine powder is less than 75 μm, which cannot be used as raw material for producing chlorination titanium dioxide, and can be sold at a low price to sponge titanium or sulfuric acid titanium dioxide manufacturers. Therefore, some researchers have tried to use high-titanium slag fine powder for producing chlorination titanium dioxide after bonding and granulating, but the bonding and granulating structure of the high-titanium slag fine powder has the disadvantage of poor strength, which is easy to be scattered and blown out in the chlorination furnace.

[0005] In summary, in the production process of chlorination titanium dioxide, the dust and high-titanium slag fine powder have a fine particle size and are easily blown out, so they cannot be fully recycled. Therefore, how to increase the particle size of the dust and high-titanium slag fine powder, and then fully recycle the electric furnace dust and high-titanium slag fine powder for smelting, improve the yield of titanium dioxide, and realize the resource utilization of by-products, has become an urgent technical problem to be solved. SUMMARY

[0006] The present application provides a method for smelting high-titanium slag with multiple raw materials, which fully recycles the by-products electric furnace dust and high-titanium slag fine powder, and reduces the generation of high-titanium slag fine powder while ensuring that the purity and particle size of the high-titanium slag meet the production requirements of chlorination titanium dioxide.

[0007] The technical scheme adopted by the present application to solve the technical problems is:

[0008] The electric furnace dust, high-titanium slag fine powder, and titanium concentrate are used as raw materials to smelt high-titanium slag. The electric furnace dust is the smoke or fine particles collected during the smelting of high-titanium slag in an electric furnace, with a particle size of <75 μm and main components of titanium, iron, and other associated element oxides. The high-titanium slag fine powder is a powdery material generated during the processing of high-titanium slag, with a particle size of <75 μm and main components of titanium dioxide and associated iron, silicon, calcium, magnesium, and other oxides. The titanium concentrate is the raw material for preparing high-titanium slag, with a particle size range of 3-15 mm.

[0009] The present application provides a method for smelting high-titanium slag with multiple raw materials, which fully recycles the by-products electric furnace dust and high-titanium slag fine powder, and reduces the generation of high-titanium slag fine powder while ensuring that the purity and particle size of the high-titanium slag meet the production requirements of chlorination titanium dioxide.

[0010] S1: Add a binder and water to the electric furnace dust and stir to obtain a first dust block;

[0011] S2: Roll, crush, and sieve the first dust block to obtain a second dust block;

[0012] S3: Mix the second dust block into the titanium concentrate to form a first mixture;

[0013] S4: Add a reducing agent to the first mixture to form a second mixture;

[0014] S5: Add the second mixture and high-titanium slag fine powder to an electric furnace for joint smelting to obtain high-titanium slag and regenerated electric furnace dust;

[0015] S6: Cool, crush, and classify the high-titanium slag to obtain a high-titanium slag product and regenerated high-titanium slag fine powder.

[0016] The step S1 is to send the electric furnace dust to the raw material bin by using pneumatic conveying, to add the binder and water and to stir for 5-10 min to obtain the first dust block. The first dust block is the dust pellet obtained by mixing and stirring the electric furnace dust, the binder and the water. Since the particle size of the electric furnace dust is extremely fine, the particle size is less than 75 μm. In the recycling process, the electric furnace dust needs to be firmly bonded so that it can stay in the subsequent high-temperature environment for a period of time, and the iron, titanium and other metals can have a chance to change their forms, so that the dust can be high-temperature bonded and melted to reduce the amount of dust carried by the wind. The electric furnace dust is firmly bonded by adding the binder and the water to make the dust pellet with certain strength, so as to increase the particle size of the bonding structure of the electric furnace dust and improve the recycling rate of the electric furnace dust.

[0017] The binder is one of dextrin, starch and polyvinyl alcohol, and the adding amount of the binder is 0.1%-1% of the mass of the electric furnace dust. The application uses one of dextrin, starch and polyvinyl alcohol as the binder. The dextrin, starch and PVA are all high-molecular organic substances, which can significantly improve the blocking strength of the electric furnace dust. In addition, the binder has excellent bonding performance when the adding amount is in the range of 0.1%-1%, which can increase the particle size and structural strength of the dust pellet. If the amount of the binder is insufficient, the bonding force between the electric furnace dust particles will be insufficient, which will lead to insufficient particle size and strength of the prepared dust pellet, and the dust pellet is easy to be scattered in the subsequent granulation process, which affects the recycling rate of the electric furnace dust. On the contrary, if the amount of the binder is too much, the electric furnace dust particles will be aggregated, which will reduce the granulation efficiency and affect the uniformity of the dust pellet.

[0018] The adding amount of the water is 0-5% of the mass of the electric furnace dust. The application can improve the bonding effect of the binder by adding a small amount of water to keep the surface of the dust slightly wet. If the adding amount of the water is too high, the binder will be diluted, which will reduce the bonding performance of the binder, lead to insufficient particle size and strength of the prepared dust pellet, and the dust pellet is easy to be scattered in the subsequent granulation process, which affects the recycling rate of the electric furnace dust.

[0019] The step S2 includes:

[0020] The first dust block is sent to the roll press to be rolled to obtain the coarse dust block. The application rolls the first dust block by using the roll press under the pressure of 10-50 kN to obtain the coarse dust block with certain strength. If the pressure is too low, the structure of the obtained coarse dust block will be loose and the strength will be low. If the pressure is too high, the subsequent crushing process will be difficult.

[0021] The coarse dedusting ash block is crushed by a crusher to obtain a fine dedusting ash block; wherein the crushing screen plate is 500*510 microns; the coarse dedusting ash block is crushed by the crusher with the crushing screen plate of 500*510 microns to obtain the fine dedusting ash block with a certain particle size, and the 500*510 micron screen plate can ensure that the particle size of the crushed fine dedusting ash block is accurately controlled below 0.5 mm, so that it meets the particle size requirement of the subsequent screening process.

[0022] The fine dedusting ash block is screened by a screening machine, and the fine dedusting ash block with a particle size not less than 22 mesh is screened out as a second dedusting ash block; wherein the fine dedusting ash block with a particle size less than 22 mesh is returned to the granulating roller press for re-rolling. This step in the present application can realize particle size grading of the fine dedusting ash block, strictly screen out the fine dedusting ash block meeting the process requirement as the second dedusting ash block, and improve the raw material utilization rate, return the fine dedusting ash block not meeting the particle size requirement to the granulating roller press for re-rolling, and reduce waste.

[0023] In step S3, the second dedusting ash block is mixed into the titanium concentrate to obtain the first mixture; wherein the second dedusting ash block and the titanium concentrate are mixed in a mass percentage of 0.03:1-0.05:1. By adjusting the mixing ratio of the second dedusting ash and the titanium concentrate, the contents of TiO2, TFe, CaO, MgO, SiO2, Al2O3, V2O5, MnO and H2O in the final product high-titanium slag are adjusted, so that the obtained high-titanium slag meets the standard executed by titanium chloride white powder manufacturers, i.e. the components of the high-titanium slag are TiO2:≥85.0%, TFe:≤8.0%, CaO:≤0.40%, MgO:≤2.5%, SiO2:≤3.5%, Al2O3:≤3.0%, V2O5:≤0.4%, MnO:≤3.0%, and H2O:≤0.2%. After the second dedusting ash block is mixed with the titanium concentrate and then sent into the electric furnace, the second dedusting ash block is more uniformly distributed, the weight of the titanium concentrate can press the second dedusting ash block, the amount of the second dedusting ash block blown out in the electric furnace smelting process is reduced, and the full recycling of the electric furnace dedusting ash is realized.

[0024] The titanium concentrate can use 50 ore with a TiO2 grade of 50%, or can use low-grade ore and high-grade ore in combination, such as 52 ore (TiO2 grade of 52%):48 ore (TiO2 grade of 48%)=1:1, 54 ore (TiO2 grade of 54%):46 ore (TiO2 grade of 46%)=1:1, and 52 ore (TiO2 grade of 52%):46 ore (TiO2 grade of 46%)=7:3, so that the TiO2 in the first mixture is≥50%.

[0025] In step S4, the first mixture is sent into the electric furnace to obtain the high-titanium slag.

[0026] The first mixture is sent into a titanium concentrate daily bunker and a titanium concentrate weighing bunker in sequence via a titanium concentrate bucket elevator, and then is discharged from the titanium concentrate weighing bunker to a mixture belt;

[0027] The reducing agent is sent into a reducing agent daily bunker and a reducing agent weighing bunker in sequence via a reducing agent bucket elevator, and then is discharged from the reducing agent weighing bunker to the mixture belt;

[0028] The first mixture is mixed with the reducing agent to form a second mixture; wherein the reducing agent is one of metallurgical coke and anthracite, and the adding amount of the reducing agent is 12% to 15% of the total mass of the second mixture, and the carbon content of the reducing agent is ≥ 84%. In the present application, the amount of the reducing agent is controlled so that the metal oxides in the raw materials are selectively reduced to metals in the process of electric furnace smelting, and the generated titanium dioxide is enriched in the slag, and the high-titanium slag is obtained after separation.

[0029] The step S5 comprises:

[0030] The second mixture is sent from the mixture belt to the ring-shaped bunkers 1-10 via a ring-shaped distributor, and then is added to the electric furnace after passing through the ring-shaped bunkers 1-10. In the present application, the high-titanium slag smelting is carried out in the electric furnace, so the raw materials need to be transported to the electric furnace to wait for smelting.

[0031] The high-titanium slag fine powder is added to the ring-shaped distributor, is sent to the ring-shaped bunker 11 via the ring-shaped distributor, and then is added to the electric furnace from the center pipe after passing through the ring-shaped bunker 11; wherein the adding amount of the high-titanium slag fine powder is 10% to 15% of the total mass of the second mixture, and is added after the completion of the tapping of the iron; in the present application, the high-titanium slag fine powder is added from the center pipe and is mainly added after the completion of the tapping of the iron, so that the high-titanium slag fine powder can be reduced to be blown out by the wind in the process of electric furnace smelting, the particle size of the high-titanium slag fine powder can be reshaped, the structural particle size of the high-titanium slag fine powder can be further increased, the high-titanium slag fine powder can be fully recycled, and the economic benefit of the high-titanium slag can be improved. In addition, the high-titanium slag fine powder is added from the center pipe, so the step of agglomeration granulation can be reduced, and the cost can be saved.

[0032] The second mixture and the high-titanium slag fine powder are jointly smelted to obtain high-titanium slag and regenerated electric furnace dust collecting ash; wherein the high-titanium slag smelting is a continuous operation, the power is cut off during tapping and tapping of the iron, the power is turned on after the completion of the tapping of the iron, the power-on rate of the ore is 1400 to 1500 kwh / h, the smelting time is 8 to 10 h, and the tapping temperature is 1600 to 1650 ℃; wherein the obtained regenerated electric furnace dust collecting ash is used as the electric furnace dust collecting ash in the step S1. In the present application, the high-titanium slag is efficiently extracted and the waste materials are recycled through joint smelting, and the continuity and environmental protection of the production are also considered.

[0033] In step S6, the high-titanium slag is cooled, crushed and classified to obtain high-titanium slag products and regenerated high-titanium slag fine powder; the obtained regenerated high-titanium slag fine powder is used as high-titanium slag fine powder in step S5.

[0034] In step S5, the regenerated electric furnace dust is collected and returned to step S1 as the raw material of the electric furnace dust, and steps S1-S6 are repeated.

[0035] In step S6, the regenerated high-titanium slag fine powder is returned to step S5 as the raw material of the high-titanium slag fine powder, and steps S5-S6 are repeated.

[0036] The chlorination method titanium dioxide production has strict requirements on the components of the raw material high-titanium slag, and the index requirements are TiO2: ≥85.0%, TFe: ≤8.0%, CaO: ≤0.40%, MgO: ≤2.5%, SiO2: ≤3.5%, Al2O3: ≤3.0%, V2O5: ≤0.4%, MnO: ≤3.0%, and H2O: ≤0.2%. When the electric furnace dust, high-titanium slag fine powder and titanium concentrate are used as raw materials to prepare high-titanium slag, the addition amount of the electric furnace dust and the high-titanium slag fine powder needs to be strictly controlled so that the final obtained high-titanium slag products meet the purity index requirements of the chlorination method titanium dioxide production.

[0037] In summary, the present application is directed to the problem that the electric furnace dust and high-titanium slag fine powder cannot be fully recycled and utilized due to the fine particle size, and innovatively proposes a method of smelting high-titanium slag by using multiple raw materials. On the one hand, by adding a binder to increase the particle size and strength of the electric furnace dust structure, the electric furnace dust is prevented from being carried away by the wind in the electric furnace, and the titanium yield is improved. By mixing the titanium concentrate in proportion, the electric furnace dust is more evenly distributed, and the electric furnace dust is pressed down by the weight of the titanium concentrate, reducing the amount of electric furnace dust carried out by the wind, and fully realizing the full recycling of electric furnace dust. On the other hand, the high-titanium slag fine powder is added from the center material pipe, and mainly after the tapping of the iron is completed, reducing the amount of high-titanium slag fine powder carried out by the wind, improving the titanium yield, and increasing the structure particle size of the high-titanium slag fine powder by remolding the particle size of the high-titanium slag fine powder in the form of recycling, fully realizing the full recycling of high-titanium slag fine powder. Based on the method provided by the present application, the electric furnace dust and high-titanium slag fine powder generated in the smelting of high-titanium slag are recycled and smelted, combined with titanium concentrate to prepare high-titanium slag products that meet the purity and particle size requirements of titanium chloride white powder raw materials, while reducing the proportion of regenerated high-titanium slag fine powder, mineral consumption and ton of slag power consumption, improving the yield of titanium dioxide, reducing the impact of the stacking of by-products on the environment, reducing the production cost of high-titanium slag, and having a wide application prospect. BRIEF DESCRIPTION OF DRAWINGS

[0038] Figure 1 is a step flow chart of a method of smelting high-titanium slag by using multiple raw materials provided by the present application;

[0039] Figure 2 is a process equipment system diagram of a method of smelting high-titanium slag by using multiple raw materials provided by the present application. DETAILED DESCRIPTION

[0040] The embodiments of the present application will be described in more detail below. The present application can be implemented in various forms, and should not be interpreted as being limited to the embodiments set forth herein, but rather, the embodiments are provided to make the present application more thoroughly and completely understood. It should be understood that the embodiments of the present application are for exemplary purposes only, and are not intended to limit the scope of protection of the present application.

[0041] The term "comprising" used in the present application is open inclusion, that is, "including but not limited to". The term "according to" is "at least partially according to". The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment". Related definitions of other terms will be given in the following description.

[0042] Embodiment 1: high-titanium slag is prepared by using electric furnace dust, high-titanium slag fine powder and titanium concentrate as raw materials, and the process flow is as shown in Figure 1 , and the specific steps include:

[0043] S1: as shown in the figure, the dust of the electric furnace is sent to the raw material bin as shown in the figure by pneumatic conveying, a binder and water are added and stirred for 5-10 min to obtain first dust blocks; wherein the components of the dust of the electric furnace are TiO2: 46.58%, TFe: 22.18%, CaO: 0.33%, MgO: 1.17%, SiO2: 9.04%, Al2O3: 1.11%, V2O5: 0.15%, MnO: 1.15%; the binder is dextrin, and the amount of the binder added is 0.5% of the mass of the dust of the electric furnace; the amount of water added is 1% of the mass of the dust of the electric furnace; wherein the first dust blocks are dust pellets obtained by mixing and stirring the dust of the electric furnace, the binder and water; Figure 2 Figure 2 S2: as shown in the figure, the first dust blocks obtained in step S1 are sent from the raw material bin to the roll press for rolling to obtain coarse dust blocks; wherein the applied pressure of the rolling process is 10-50 kN;

[0044] S3: the second dust blocks obtained in step S2 are mixed into the titanium concentrate to obtain a first mixture; wherein the second dust blocks and the titanium concentrate are mixed according to a mass percentage of 0.03:1; the titanium concentrate uses 50 ore with a TiO2 grade of 50%, and the components thereof are TiO2: 50.60%, TFe: 30.75%, CaO: 0.16%, MgO: 0.40%, SiO2: 1.57%, Al2O3: 1.21%, V2O5: 0.21%, MnO: 1.32%, so that TiO2 in the first mixture is ≥50%; Figure 2 S4: as shown in the figure, the first mixture obtained in step S3 is sequentially sent into the titanium concentrate daily bin and the titanium concentrate weighing bin via the titanium concentrate bucket elevator, and then is discharged from the titanium concentrate weighing bin to the mixing belt;

[0045] The reducing agent is sequentially sent into the reducing agent daily bin and the reducing agent weighing bin via the reducing agent bucket elevator, and then is discharged from the reducing agent weighing bin to the mixing belt;

[0046] S5: as shown in the figure, the first mixture and the reducing agent are mixed in the mixing belt to obtain a second mixture; wherein the mixing ratio of the first mixture to the reducing agent is 0.03:1;

[0047] S6: as shown in the figure, the second mixture obtained in step S5 is sent to the reduction furnace via the reduction furnace bucket elevator, and then is reduced in the reduction furnace to obtain titanium slag; wherein the reduction temperature of the reduction furnace is 1,300-1,500°C, and the reduction time is 1-2 h;

[0048] Figure 2 S7: as shown in the figure, the titanium slag obtained in step S6 is sent to the slag granulation tank via the slag granulation tank bucket elevator, and then is granulated in the slag granulation tank to obtain titanium slag granules; wherein the granulation temperature of the slag granulation tank is 1,300-1,500°C, and the granulation time is 1-2 h;

[0049] S8: as shown in the figure, the titanium slag granules obtained in step S7 are sent to the titanium slag granulation tank via the titanium slag granulation tank bucket elevator, and then are granulated in the titanium slag granulation tank to obtain titanium slag granules; wherein the granulation temperature of the titanium slag granulation tank is 1,300-1,500°C, and the granulation time is 1-2 h;

[0050] ​​The first mixture is mixed with a reducing agent in an electric furnace to form a second mixture; wherein the reducing agent is metallurgical coke, and the amount of the reducing agent is 12% of the total mass of the second mixture, and the carbon content of the reducing agent is ≥ 84%;

[0051] S5: As shown in the figure, the second mixture obtained in step S4 is sent from the mixing belt to the ring feeder through the ring feeder, and then to the ring feeder No. 1-10, and then to the electric furnace after passing through the ring feeder No. 1-10; Figure 2

[0052] The high-titanium slag fine powder is added to the ring feeder, and then sent to the ring feeder No. 11 through the ring feeder, and then added to the electric furnace through the ring feeder No. 11 from the center pipe; wherein the amount of the high-titanium slag fine powder is 10% of the total mass of the second mixture, and is added after the completion of the iron tapping; wherein the components of the high-titanium slag fine powder are TiO2: 85.21%, TFe: 6.04%, CaO: 0.28%, MgO: 1.79%, SiO2: 3.32%, Al2O3: 2.42%, V2O5: 0.32%, and MnO: 1.23%;

[0053] The second mixture and the high-titanium slag fine powder in the electric furnace are jointly smelted to obtain high-titanium slag and regenerated electric furnace dust; wherein the smelting of the high-titanium slag is continuous, and the power is cut off during tapping and iron tapping, and the power is turned on after the completion of the iron tapping, the ore-electricity ratio is 1400-1500 kwh / h, the smelting time is 8-10 h, and the tapping temperature is 1600-1650℃; wherein the obtained regenerated electric furnace dust is used as the electric furnace dust in step S1;

[0054] S6: The high-titanium slag obtained in step S5 is cooled, crushed, and classified to obtain high-titanium slag products and regenerated high-titanium slag fine powder; wherein the obtained regenerated high-titanium slag fine powder is used as the high-titanium slag fine powder in step S5.

[0055] The regenerated electric furnace dust produced in step S5 is collected and returned to step S1 as the raw material of the electric furnace dust, and steps S1-S6 are repeated.

[0056] The regenerated high-titanium slag fine powder produced in step S6 is returned to step S5 as the raw material of the high-titanium slag fine powder, and steps S5-S6 are repeated.

[0057] ​Example 2: Preparation of high-titanium slag with electric furnace dust, high-titanium slag fine powder and titanium concentrate as raw materials: starch is used as the binder; anthracite is used as the reducing agent; the second dust block and the titanium concentrate are mixed according to a mass percentage of 0.05:1, and the titanium concentrate is used in combination of low-grade ore and high-grade ore, and 54 ore (TiO2 grade of 54%) and 46 ore (TiO2 grade of 46%) are used in combination in this example, and the ratio of 54 ore (TiO2 grade of 54%) to 46 ore (TiO2 grade of 46%) is 1:1; wherein the components of 54 ore are TiO2: 54.1%, TFe: 31.5%, CaO: 23.02%, MgO: 19.45%, SiO2: 0%, Al2O3: 0.3947%, V2O5: 0.3754%, and MnO: 0.4988%; the components of 46 ore are TiO2: 46.4%, TFe: 37.54%, CaO: 30.56%, MgO: 19.71%, SiO2: 0.1581%, Al2O3: 0.3872%, V2O5: 0.8493%, and MnO: 0.3344%, so that the TiO2 in the first mixture is ≥50%. The remaining conditions in this example are the same as those in Example 1.

[0058] Example 3: Preparation of high-titanium slag with electric furnace dust, high-titanium slag fine powder and titanium concentrate as raw materials: polyvinyl alcohol is used as the binder; the second dust block and the titanium concentrate are mixed according to a mass percentage of 0.04:1. The remaining conditions in this example are the same as those in Example 1.

[0059] Example 4: Preparation of high-titanium slag with electric furnace dust, high-titanium slag fine powder and titanium concentrate as raw materials: the addition amount of high-titanium slag fine powder is 12.5% of the total mass of the second mixture. The remaining conditions in this example are the same as those in Example 1.

[0060] Example 5: Preparation of high-titanium slag with electric furnace dust, high-titanium slag fine powder and titanium concentrate as raw materials: the addition amount of high-titanium slag fine powder is 15% of the total mass of the second mixture. The remaining conditions in this example are the same as those in Example 1.

[0061] Example 6: Preparation of high-titanium slag with electric furnace dust, high-titanium slag fine powder and titanium concentrate as raw materials: the addition amount of the binder is 0.1% of the mass of the electric furnace dust. The remaining conditions in this example are the same as those in Example 1.

[0062] Example 7: Preparation of high-titanium slag with electric furnace dust, high-titanium slag fine powder and titanium concentrate as raw materials: the addition amount of the binder is 1% of the mass of the electric furnace dust. The remaining conditions in this example are the same as those in Example 1.

[0063] Example 8: Preparation of high-titanium slag with electric furnace dust, high-titanium slag fine powder and titanium concentrate as raw materials: the addition amount of the binder is 1% of the mass of the electric furnace dust, and no water is added to the electric furnace dust. The remaining conditions in this example are the same as those in Example 1.

[0064] Example 9: High-titanium slag was prepared by using the electric furnace dust, high-titanium slag fine powder and titanium concentrate as raw materials, the addition amount of the binder was 1% of the mass of the electric furnace dust, and the addition amount of water was 2.5%. The remaining conditions of this example were the same as those of Example 1.

[0065] Example 10: High-titanium slag was prepared by using the electric furnace dust, high-titanium slag fine powder and titanium concentrate as raw materials, the addition amount of the binder was 1% of the mass of the electric furnace dust, and the addition amount of water was 5%. The remaining conditions of this example were the same as those of Example 1.

[0066] Example 11: High-titanium slag was prepared by using the electric furnace dust, high-titanium slag fine powder and titanium concentrate as raw materials, the addition amount of the reducing agent was 15% of the total mass of the second mixture. The remaining conditions of this example were the same as those of Example 1.

[0067] Example 12: High-titanium slag was prepared by using the electric furnace dust, high-titanium slag fine powder and titanium concentrate as raw materials, the addition amount of the reducing agent was 13.5% of the total mass of the second mixture. The remaining conditions of this example were the same as those of Example 1.

[0068] Comparative Example 1: High-titanium slag was prepared by using the electric furnace dust and the titanium concentrate as raw materials without adding the high-titanium slag fine powder, and the remaining conditions were the same as those of Example 1.

[0069] Comparative Example 2: High-titanium slag was prepared by using the high-titanium slag fine powder and the titanium concentrate as raw materials without adding the electric furnace dust, and the remaining conditions were the same as those of Example 1.

[0070] Comparative Example 3: High-titanium slag was prepared by using the titanium concentrate as raw material without adding the electric furnace dust and the high-titanium slag fine powder, and the remaining conditions were the same as those of Example 1.

[0071] Table 1 shows the detection results of the chemical components of the high-titanium slag in different examples and comparative examples, Table 2 shows the particle size distribution of the high-titanium slag in different examples and comparative examples, and Table 3 shows the proportion of the regenerated high-titanium slag fine powder, the ore consumption and the power consumption per ton of slag in different examples and comparative examples. The purity and the particle size of the high-titanium slag are required in the production of titanium dioxide by chlorination, and the corresponding qualified indexes of the purity and the particle size are shown in Table 1 and Table 2, respectively.

[0072] As shown in Table 1, the content of each component of the high-titanium slag prepared in the examples of the present application is within the qualified index range, and the purity can meet the purity index requirement for preparing titanium dioxide by chlorination.

[0073] Comparing Example 1, Example 3 and Comparative Example 2, under the condition that the adding amount of high-titanium slag fine powder, titanium concentrate, binder, water and reducing agent is the same, the second dust block: titanium concentrate in Example 1 is controlled to be 0.03:1, the second dust block: titanium concentrate in Example 3 is controlled to be 0.04:1, and no electric furnace dust is added in Comparative Example 2. As shown in Table 2, the particles with a particle size of <75 μm in the high-titanium slag prepared in Example 1 account for 6.10%, the particles with a particle size of <400 μm account for 74.20%, and the particles with a particle size of >830 μm account for 4.60%; the particles with a particle size of <75 μm in the high-titanium slag prepared in Example 3 account for 4.50%, the particles with a particle size of <400 μm account for 72.18%, and the particles with a particle size of >830 μm account for 3.45%; the particles with a particle size of <75 μm in the high-titanium slag prepared in Comparative Example 2 account for 4.10%, the particles with a particle size of <400 μm account for 73.85%, and the particles with a particle size of >830 μm account for 3.99%. Example 1, Example 3 and Comparative Example 2 all meet the particle size index requirements for preparing chlorination process titanium dioxide, and among them, the particles with a particle size of <75 μm in Example 3 account for the lowest proportion, the particles with a particle size of <400 μm account for the highest proportion, and the particles with a particle size of >830 μm account for the lowest proportion, which indicates that the high-titanium slag fine powder produced in Example 3 is the least, and the particle size distribution is the narrowest, and the particle size is concentrated in the <400 μm part. Therefore, the high-titanium slag prepared in Example 3 has the optimal particle size distribution, which means that the addition of an appropriate amount of electric furnace dust in the present application for preparing high-titanium slag can not only ensure that the purity of the high-titanium slag meets the requirements for preparing chlorination process titanium dioxide, but also further optimize the particle size distribution of the high-titanium slag, so as to produce less high-titanium slag fine powder.

[0074] In addition, as shown in Table 3, the proportion of regenerated high-titanium slag fine powder in Example 1 is 11.25%, the ore consumption is 1.79 t / t, and the power consumption per ton of slag is 2457 kwh / t; the proportion of regenerated high-titanium slag fine powder in Example 3 is 11.59%, the ore consumption is 1.81 t / t, and the power consumption per ton of slag is 2465 kwh / t; the proportion of regenerated high-titanium slag fine powder in Comparative Example 2 is 12.26%, the ore consumption is 1.86 t / t, and the power consumption per ton of slag is 2457 kwh / t. It can be known that the proportion of regenerated high-titanium slag fine powder, the ore consumption and the power consumption per ton of slag produced in Example 1 and Example 3 are all lower than those in Comparative Example 2, and the lowest is in Example 3, which indicates that the addition of electric furnace dust can effectively reduce the production of regenerated high-titanium slag fine powder, and reduce the ore consumption and the power consumption per ton of slag, thereby reducing the cost.

[0075] Comparing Example 4, Example 5 and Comparative Example 1, under the condition that the addition amounts of the electric furnace dust, titanium concentrate, binder, water and reducing agent are the same, the addition amount of the high-titanium slag fine powder in Example 4 is controlled to be 12.5%, the addition amount of the high-titanium slag fine powder in Example 5 is controlled to be 15%, and no high-titanium slag fine powder is added in Comparative Example 1. As shown in Table 2, the particles with a particle size <75 μm account for 3.24%, the particles with a particle size <400 μm account for 75.63%, and the particles with a particle size >830 μm account for 4.35% in the high-titanium slag prepared in Example 4, the particles with a particle size <75 μm account for 4.23%, the particles with a particle size <400 μm account for 76.32%, and the particles with a particle size >830 μm account for 5.36% in the high-titanium slag prepared in Example 5, and the particles with a particle size <75 μm account for 4.42%, the particles with a particle size <400 μm account for 75.68%, and the particles with a particle size >830 μm account for 4.22% in the high-titanium slag prepared in Comparative Example 1. All of Example 4, Example 5 and Comparative Example 1 meet the particle size index requirements for preparing the titanium dioxide by the chlorination method, and among them, the proportion of the particles with a particle size <75 μm is the lowest and the proportion of the particles with a particle size <400 μm is the highest in Example 4, which indicates that the high-titanium slag fine powder produced in Example 3 is the least and the particle size distribution is relatively narrow, and the particle size is mainly concentrated in the <400 μm part. Therefore, the addition of the appropriate amount of the high-titanium slag fine powder in this application can ensure that the purity of the high-titanium slag meets the requirements for preparing the titanium dioxide by the chlorination method while producing less high-titanium slag fine powder. In addition, as shown in Table 3, the proportion of the regenerated high-titanium slag fine powder and the power consumption per ton of slag produced in Example 4 and Example 5 are both significantly lower than those in Comparative Example 2, and Example 5 is the lowest, which indicates that the addition of the high-titanium slag fine powder can effectively reduce the production of the regenerated high-titanium slag fine powder and the power consumption per ton of slag, thereby reducing the cost.

[0076] Comparing Example 5, Example 6 and Example 7, under the condition that the addition amounts of the electric furnace dust, high-titanium slag fine powder, titanium concentrate, water and reducing agent are the same, the addition amount of the binder in Example 5 is controlled to be 0.5%, the addition amount of the binder in Example 6 is controlled to be 0.1%, and the addition amount of the binder in Example 7 is controlled to be 1%. As shown in Table 2, the particles with a particle size <75 μm account for 3.24% in the high-titanium slag prepared in Example 6, which is lower than that in Example 5 and Example 7, which indicates that Example 6 produces less high-titanium slag fine powder, and therefore the appropriate addition amount of the binder can effectively reduce the production of the high-titanium slag fine powder.

[0077] Comparing Example 8, Example 9 and Example 10, under the condition that the adding amount of the electric furnace dust, high-titanium slag fine powder, titanium concentrate, binder and reducing agent is the same, Example 8 does not add water, Example 9 controls the adding amount of water to be 2.5%, and Example 10 controls the adding amount of water to be 5%. As shown in Table 2, the particles with a particle size of <75 μm in the high-titanium slag prepared in Example 8 account for 3.56%, the particles with a particle size of <75 μm in the high-titanium slag prepared in Example 9 account for 4.23%, and the particles with a particle size of <75 μm in the high-titanium slag prepared in Example 10 account for 3.99%. It can be seen that with the increase of the adding amount of water, the proportion of the particles with a particle size of <75 μm in the high-titanium slag presents a trend of first increasing and then decreasing, which indicates that the addition of water helps the binder to function and further promotes the adhesion of the binder to the electric furnace dust.

[0078] Comparing Example 10, Example 11 and Example 12, under the condition that the adding amount of the electric furnace dust, high-titanium slag fine powder, titanium concentrate, binder and water is the same, Example 10 controls the adding amount of the reducing agent to be 12%, Example 11 controls the adding amount of the reducing agent to be 15%, and Example 12 controls the adding amount of the reducing agent to be 13.5%. As shown in Table 2, the particles with a particle size of <75 μm in the high-titanium slag prepared in Example 10 account for 3.99%, and the particles with a particle size of <75 μm in the high-titanium slag prepared in Example 11 and Example 12, which indicates that Example 10 produces less high-titanium slag fine powder, and thus a suitable adding amount of the reducing agent can promote the reduction of the high-titanium slag fine powder.

[0079] Table 1: Test results of chemical composition of high-titanium slag

[0080]

[0081]

[0082] Table 2: Particle size distribution of high-titanium slag

[0083] Test item < 75 μm (%) < 400 μm (%) > 830 μm (%) Acceptance criteria ≤10.0 ＜80.0 ≤10.0 Example 1 6.10 74.20 4.60 Example 2 5.00 78.50 2.80 Example 3 4.50 72.18 3.45 Example 4 3.24 75.63 4.35 Example 5 4.23 76.32 5.36 Example 6 3.85 74.38 4.23 Example 7 4.56 73.33 5.65 Example 8 3.56 74.36 4.22 Example 9 4.23 76.33 3.55 Example 10 3.99 72.44 3.75 Example 11 4.32 73.55 3.88 Example 12 4.33 74.85 4.13 Comparative Example 1 4.42 75.68 4.22 Comparative Example 2 4.10 73.85 3.99 Comparative Example 3 4.20 75.68 4.13

[0084] Table 3: Proportion of regenerated high-titanium slag fine powder, ore consumption and power consumption per ton of slag

[0085]

[0086] The above merely illustrates the specific embodiments of the present application, but the protection scope of the present application is not limited thereto, any person skilled in the art can easily think of changes or replacements within the technical range disclosed in the present application, which should be covered in the protection scope of the present application, thus the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A method for combined smelting of high titanium slag using a plurality of raw materials, characterized in that, The method comprises the following steps: S1: adding a binder and water to the electric furnace dust and stirring to obtain first dust briquettes; S2: rolling, crushing and screening the first dust briquettes to obtain second dust briquettes; S3: mixing the second dust briquettes into titanium concentrate to form a first mixture; S4: adding a reducing agent to the first mixture to form a second mixture; S5: jointly smelting the second mixture and high-titanium slag powder in an electric furnace to obtain high-titanium slag and regenerated electric furnace dust; S6: cooling, crushing and grading the high-titanium slag to obtain high-titanium slag products and regenerated high-titanium slag powder.

2. The method for producing high-titanium slag by combined smelting of multiple raw materials according to claim 1, characterized in that, Step S1 is to use pneumatic conveying to send the electric furnace dust to the raw material bin, add a binder and water and stir for 5-10 minutes to obtain the first dust briquettes.

3. The method for producing high-titanium slag by combined smelting of multiple raw materials according to claim 1, characterized in that, The first dust briquettes are electric furnace dust, a binder and water mixed and stirred.

4. The method for producing high-titanium slag by combined smelting of multiple raw materials according to claim 1, characterized in that, The binder is one of dextrin, starch and polyvinyl alcohol.

5. The method for producing high titanium slag by combined smelting of multiple raw materials according to claim 1, characterized in that, The amount of the binder added is 0.1%-1% of the mass of the electric furnace dust.

6. The method for combined smelting of high titanium slag from multiple raw materials according to claim 1, characterized in that, The amount of water added is 0-5% of the mass of the electric furnace dust.

7. The method for combined smelting of high titanium slag from multiple raw materials according to claim 1, characterized in that, Step S2 comprises: The first dust briquettes are sent to a granulating roller press for rolling to obtain coarse dust briquettes; wherein the applied pressure of the rolling process is 10-50 kN; The coarse dust briquettes are crushed by a crusher to obtain fine dust briquettes; wherein the crushing screen is 500*510 μm; The fine dust briquettes are screened by a screening machine, and the fine dust briquettes with a particle size not less than 22 mesh are screened out as the second dust briquettes; wherein the fine dust briquettes with a particle size less than 22 mesh are returned to the granulating roller press for re-rolling.

8. The method for combined smelting of high titanium slag from multiple raw materials according to claim 1, characterized in that, Step S3 is to mix the second dust briquettes into the titanium concentrate to obtain the first mixture; wherein the second dust briquettes and the titanium concentrate are mixed according to a mass percentage of 0.03:1-0.05:

1.

9. The method for combined smelting of high titanium slag from multiple raw materials according to claim 1, characterized in that, Step S4 comprises: The first mixture is sequentially sent to a titanium concentrate daily bin and a titanium concentrate weighing bin via a titanium concentrate bucket elevator, and then discharged from the titanium concentrate weighing bin to a mixture belt; The reducing agent is sequentially sent to a reducing agent daily bin and a reducing agent weighing bin via a reducing agent bucket elevator, and then discharged from the reducing agent weighing bin to the mixture belt; The first mixture is mixed with the reducing agent to form the second mixture; wherein the reducing agent is one of metallurgical coke and anthracite, and the amount of the reducing agent added is 12%-15% of the total mass of the second mixture.

10. The method for combined smelting of high titanium slag from multiple raw materials according to claim 1, characterized in that, Step S5 comprises: The second mixture is sent from the mixture belt to ring-shaped bins 1-10 via a ring-shaped distributor, and then added to the electric furnace after passing through the ring-shaped bins 1-10; The high-titanium slag powder is added to the ring-shaped distributor, sent to ring-shaped bin 11 via the ring-shaped distributor, and then added to the electric furnace from the center pipe after passing through the ring-shaped bin 11; wherein the amount of the high-titanium slag powder added is 10%-15% of the total mass of the second mixture, and the high-titanium slag powder is added after the completion of the tapping of the electric furnace. The second mixture and the high-titanium slag fine powder are jointly smelted to obtain high-titanium slag and regenerated electric furnace dust collecting ash; wherein, the high-titanium slag smelting is a continuous operation, and power is cut off when tapping slag and tapping iron, and power is turned on after the tapping iron blockage is completed, the ore power ratio is 1400-1500 kwh / h, the smelting time is 8-10 h, and the tapping slag temperature is 1600-1650 ℃; wherein, the obtained regenerated electric furnace dust collecting ash is used as the electric furnace dust collecting ash in the S1 step.

11. The method for combined smelting of high titanium slag from multiple raw materials according to claim 1, characterized in that, Step S6 is to obtain high-titanium slag products and regenerated high-titanium slag fine powder after the high-titanium slag is cooled, crushed and classified; wherein, the obtained regenerated high-titanium slag fine powder is used as the high-titanium slag fine powder in the S5 step.

12. The method for combined smelting of high titanium slag from multiple raw materials according to claim 1, characterized in that, The regenerated electric furnace dust collecting ash generated in step S5 is collected and returned to step S1 as the raw material of the electric furnace dust collecting ash, and steps S1-S6 are repeated.

13. The method for combined smelting of high titanium slag from multiple raw materials according to claim 1, characterized in that, The regenerated high-titanium slag fine powder generated in step S6 is returned to step S5 as the raw material of the high-titanium slag fine powder, and steps S5-S6 are repeated.

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