Sintering method and application of solid waste ferric hydroxide mixture and preparation method of vanadium-titanium sinter

Abstract

The invention provides a sintering method and application of a solid waste ferric hydroxide mixture and a preparation method of vanadium-titanium sinter. According to the sintering method, the solid waste ferric hydroxide mixture is subjected to oxidizing roasting pretreatment at the temperature of 700-900 DEG C, ferric hydroxide, manganese hydroxide and the like are oxidized into ferric oxide and manganese oxide, meanwhile, crystal water and part of chloride ions in the ferric hydroxide mixture are removed, and the TFe content is increased and can reach 55% or above. According to the method, the vanadium-titanium sintered ore is prepared by taking the ferric hydroxide roasted substance obtained after oxidizing roasting pretreatment as a raw material, and the operation of step-by-step uniform mixing is adopted, so that the fine-fraction vanadium-titanium magnetite concentrate, the active ash and the ferric hydroxide roasted substance can be sufficiently and uniformly mixed; therefore, in the sintering process, CaO in the ferric oxide and the active ash preferentially react to generate calcium ferrite and low-melting-point manganese oxide, the characteristic that the vanadium-titanium magnetite concentrate is difficult to sinter can be improved, and improvement of the sintering quality is promoted.

Description

Technical Field

[0001] The present invention belongs to the technical field of iron and steel metallurgy, and particularly relates to a sintering method for a solid waste iron hydroxide mixture and its application, and a method for preparing a vanadium-titanium sinter. Background Art

[0002] In the process of preparing titanium dioxide by the chlorination method in Pangang, the crude brine leached from chlorinated waste salt is subjected to stepwise precipitation and then filtered and washed by a plate and frame filter press to obtain a cake-like iron hydroxide mixture, which contains TFe grade of 25-40%, MnO content of about 3-8%, water content of about 42-58% (mostly crystal water), and dry-based Cl content of less than 0.5%. It belongs to general solid waste resources. Although it can be treated by landfill and other methods, the valuable elements iron and manganese in it will be wasted. When directly entering the sintering materials, due to the low TFe grade and high water content, it will increase the consumption of sintering solid fuel.

[0003] Based on the above problems, it is very crucial to find a method to avoid treating the iron hydroxide mixture as solid waste. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to provide a sintering method for a solid waste iron hydroxide mixture and its application, and a method for preparing a vanadium-titanium sinter. This sintering method can not only solve the disposal problem of the iron hydroxide mixture as solid waste, but also be used to prepare vanadium-titanium sinter and improve the quality of vanadium-titanium sinter.

[0005] To achieve this purpose, the present invention adopts the following technical solutions:

[0006] In the first aspect, the present invention provides a sintering method for a solid waste iron hydroxide mixture, including the following steps:

[0007] Oxidatively roast the solid waste iron hydroxide mixture to obtain an iron hydroxide roasted product.

[0008] Preferably, the temperature of the oxidative roasting is 700-900 °C.

[0009] Preferably, the time of the oxidative roasting is 25-35 min.

[0010] Preferably, after the oxidative roasting is completed, it further includes cooling and fine grinding treatments.

[0011] Preferably, after the fine grinding treatment, the proportion of the iron hydroxide roasted product with a particle size less than 0.074 mm is 40-60%.

[0012] In the second aspect, the present invention provides an application of the above iron hydroxide roasted product in the preparation of vanadium-titanium sinter.

[0013] Thirdly, the present invention provides a method for preparing vanadium-titanium sintered ore, comprising the following steps:

[0014] S1: Mix vanadium-titanium magnetite, activated ash and roasted ferric hydroxide evenly to obtain a first mixture;

[0015] S2: Mix fine ore, fuel, flux, returned ore and the first mixture evenly to obtain a second mixture;

[0016] S3: Sinter the second mixture to obtain vanadium-titanium sintered ore.

[0017] Preferably, the mixing time in steps S1 and S2 is independently 2 - 10 min.

[0018] Preferably, after the sintering in step S3, it further includes coarse crushing, dropping treatment and screening in sequence.

[0019] Preferably, the mass ratio of the vanadium-titanium magnetite, activated ash and roasted ferric hydroxide is (40 - 50):(5 - 10):(0 - 3).

[0020] Preferably, the fine ore includes domestic high-grade fine ore and domestic medium-grade fine ore.

[0021] Preferably, the fuel includes pulverized coal and / or coke powder.

[0022] Preferably, the flux includes limestone and steel slag.

[0023] Preferably, the returned ore includes blast furnace returned ore.

[0024] Preferably, the mass ratio of the domestic high-grade fine ore, domestic medium-grade fine ore, steel slag, limestone, coke powder, blast furnace returned ore is (10 - 20):(5 - 8):(1 - 3):(5 - 10):(4 - 7):(20 - 40).

[0025] Preferably, atomized water is sprayed while mixing in step S2, and the addition amount of the atomized water is 75 - 85% of the calculated total water amount.

[0026] Preferably, after the atomized water spraying is completed, water is added for granulation, and the addition amount of water is 15 - 25% of the calculated total water amount.

[0027] Preferably, the time for water addition granulation is 3 - 10 min.

[0028] Compared with the prior art, the beneficial effects of the present invention are:

[0029] The present invention provides a sintering method for a solid waste ferric hydroxide mixture. The method pre-treats the solid waste ferric hydroxide mixture by oxidative roasting at 700-900 °C, oxidizing ferric hydroxide and manganese hydroxide into iron oxide and manganese oxide, while removing the crystal water and part of the chloride ions in the ferric hydroxide mixture, increasing the TFe content, and the TFe content can reach more than 55%.

[0030] Furthermore, the present invention uses the ferric hydroxide calcine obtained after the oxidative roasting pre-treatment as a raw material to prepare a vanadium-titanium sintered ore, and adopts a step-by-step mixing operation, which can ensure the full mixing of fine-grained vanadium-titanium magnetite concentrate, active ash and ferric hydroxide calcine. Thus, during the sintering process, calcium ferrite and low-melting-point manganese oxide are preferentially formed by the reaction of iron oxide and CaO in the active ash, which can improve the difficult-to-sinter characteristics of vanadium-titanium magnetite concentrate and promote the improvement of sintering quality.

[0031] In summary, the sintering method for the solid waste ferric hydroxide mixture provided by the present invention not only recovers the organic elements iron and manganese in the secondary resources of the titanium dioxide chloride process, reduces the pollution and damage of solid waste to the environment, and has significant environmental protection benefits, but also can be used to produce high-quality vanadium-titanium sintered ore, with excellent application value. Specific Embodiments

[0032] Next, in combination with the embodiments of the present invention, the technical solutions of the present invention will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0033] Aiming at the problem that in the prior art, the cake-like ferric hydroxide mixture generated in the process of preparing titanium dioxide by the chloride process of Pangang can only be treated as solid waste, the present invention provides a sintering method for a solid waste ferric hydroxide mixture, including the following steps:

[0034] Oxidatively roast the solid waste ferric hydroxide mixture to obtain a ferric hydroxide calcine.

[0035] In the present invention, the solid waste ferric hydroxide mixture is: the cake-like ferric hydroxide mixture obtained by stepwise precipitation of the crude brine leached from the chloride waste salt in the process of preparing titanium dioxide by the chloride process of Pangang and then plate-and-frame pressure filtration and washing. After testing, the TFe grade in the solid waste ferric hydroxide mixture is 25-40%, the MnO content is about 3-8%, the moisture content is about 42-58% (mostly crystal water), and the dry-base Cl content is less than 0.5%.

[0036] Through the exploration of different temperatures, it is found that when the temperature is lower than 700 °C, the TFe grade of the roasted product of iron hydroxide cannot meet the requirements. When the temperature is higher than 900 °C, the increase in the TFe grade of the roasted product of iron hydroxide is not significant, but the energy consumption will increase. Therefore, through screening, the present invention preferably oxidatively roasts the solid waste iron hydroxide mixture at 700-900 °C for 25-35 minutes, more preferably oxidatively roasts it at 750-850 °C for 28-35 minutes, and further preferably oxidatively roasts it at 800 °C for 30-35 minutes, which can oxidize iron hydroxide and manganese hydroxide into iron oxide and manganese oxide, and at the same time remove the crystal water and part of the chloride ions in the iron hydroxide mixture, improve the TFe content, and the TFe content can reach more than 55%.

[0037] For the convenience of the subsequent application of the roasted product of iron hydroxide, the present invention preferably conducts cooling and fine grinding treatments in sequence after the oxidative roasting ends.

[0038] In the present invention, the mill for the fine grinding treatment is a ball medium cement mill, and the grinding time can be determined according to the particle size of the sample. To ensure that the roasted product of iron hydroxide can be evenly distributed between vanadium-titanium magnetite and activated ash, it is required that after fine grinding, the proportion of the roasted product of iron hydroxide with a particle size less than 0.074 mm is 40-60%, preferably 50-60%.

[0039] The present invention also provides an application of the above-mentioned roasted product of iron hydroxide in the preparation of vanadium-titanium sintered ore. In this application, the introduction of the roasted product of iron hydroxide can change the phase composition in the sintering process of vanadium-titanium sintered ore, improve the quality of vanadium-titanium sintered ore, and has certain economic benefits.

[0040] The present invention also provides a method for preparing vanadium-titanium sintered ore, which includes the following steps:

[0041] S1: Mix vanadium-titanium magnetite, activated ash and the roasted product of iron hydroxide evenly to obtain a first mixture;

[0042] S2: Mix fine ore, fuel, flux, return ore and the first mixture evenly to obtain a second mixture;

[0043] S3: Sinter the second mixture to obtain vanadium-titanium sintered ore.

[0044] According to the present invention, first, vanadium-titanium magnetite, activated ash and the roasted product of iron hydroxide are mixed evenly to obtain a first mixture. Among them, the mass ratio of vanadium-titanium magnetite, activated ash and the roasted product of iron hydroxide is (40-50):(5-10):(0-3), preferably (40-45):(8-10):(1-2), and more preferably 45:9:2. The mixing time is 2-10 minutes, preferably 3-8 minutes, and more preferably 4-6 minutes to ensure uniform mixing of the three.

[0045] It is explained here that the present invention specifically pre-mixes the calcined iron hydroxide with vanadium-titanium magnetite and activated ash, and then mixes with powder ore, fuel, flux, return ore and other materials. The reason is that: to ensure that the vanadium-titanium magnetite concentrate, activated ash and calcined iron hydroxide are fully mixed, during the sintering process, the iron oxide and CaO in the activated ash preferentially react to form calcium ferrite and low-melting-point manganese oxide, which is beneficial to improve the difficult sintering characteristics of the vanadium-titanium magnetite concentrate and promote the improvement of sintering quality. If the calcined iron hydroxide is placed in the raw material for the subsequent preparation of the second mixed material without pre-mixing, the above effect cannot be achieved.

[0046] After obtaining the first mixed material, the powder ore, fuel, flux, return ore and the first mixed material are mixed evenly to obtain the second mixed material. The mixing time is 2 to 10 minutes, preferably 3 to 8 minutes, and more preferably 4 to 6 minutes.

[0047] The present invention has no particular limitation on the equipment for the two-step mixing, and it may be a mixer.

[0048] In the present invention, the fuel includes coal powder and / or coke powder; the flux includes steel slag and limestone; and the return ore includes blast furnace return ore.

[0049] In some embodiments of the present invention, the mass ratio of domestic high powder, domestic medium powder, steel slag, limestone, coke powder and blast furnace return ore is (10-20):(5-8):(1-3):(5-10):(4-7):(20-40), preferably (15-20):(6-7):(1-3):(8-10):(5-6):(25-35), and more preferably 20:7:2:9:5:30.

[0050] It should be noted that the total mass percentage of the above-mentioned vanadium-titanium magnetite, active ash and calcined iron hydroxide, powder ore, fuel, flux and return ore is 100%.

[0051] In some preferred embodiments of the present invention, preferably, powder ore, fuel, flux, and return ore are added to the first mixture in sequence, and then mixed for 2 to 10 minutes, and sprayed with atomized water at the same time. The amount of atomized water added at this stage is 75 to 85% of the total water volume, forming a second mixture with a mosaic structure of the first mixture and powder ore, fuel, flux, and return ore. Then, preferably, the second mixture with a mosaic structure is added to the second mixer for water granulation. The amount of water added at this stage is 15 to 25% of the total water volume, and the water granulation time is set to 3 to 10 minutes, preferably 5 to 7 minutes, to ensure that the second mixture with a mosaic structure rolls evenly into balls, and to ensure that the portion larger than 3 mm in the mixture reaches 50 to 70%, preferably 60 to 70%, which is conducive to improving the air permeability of the material layer and improving the sintering effect.

[0052] The total amount of water calculated above = the dry basis of all the above materials (i.e., the sum of powdered ore, fuel, flux, and return ore) × the set moisture percentage / (1 - the set moisture percentage) + the water consumption for the digestion of CaO in the flux (referring to limestone and steel slag).

[0053] After obtaining the second mixture, sinter it to obtain the vanadium-titanium sinter.

[0054] The present invention does not particularly limit the sintering method, and any technical means well-known to those skilled in the art can be used.

[0055] Exemplarily, the sintering includes the following steps:

[0056] Load the second mixture into a sintering cup (with a diameter of 300 mm and a height of 800 mm, the diameter and height can be adjusted according to actual needs). The particle size of the bottom layer material in the sintering cup is 10 - 16 mm, the thickness of the bottom layer material is 15 - 25 mm, and the thickness of the material layer is 650 - 700 mm (including the thickness of the bottom layer material);

[0057] Carry out ignition and suction sintering on the second mixture in the sintering cup. The ignition temperature is 1100 - 1150 °C, the ignition time is 2.5 - 3.0 min, the ignition negative pressure is 5.5 - 6.0 kPa, the sintering suction negative pressure is 11.5 - 12.5 kPa, and the suction flow rate is 5 - 15 m 3 / min;

[0058] When the waste gas temperature at the lower end suction pipe of the sintering cup rises to the highest and then drops to 50 °C, the sintering process ends, and a sintered cake is obtained, that is, the vanadium-titanium sinter.

[0059] In some embodiments of the present invention, it is preferably to pour out the sintered cake and successively carry out coarse crushing, dropping treatment, and screening.

[0060] Specifically, pour out the sintered cake and carry out coarse crushing (the spacing of the crusher is 50 mm), then carry out 3 times of dropping treatment (the dropping height is 2 m), and then screen according to 40 - 25 mm, 25 - 16 mm, 16 - 10 mm, 10 - 5 mm, <5 mm, calculate the proportion of >5 mm, obtain the finished product of vanadium-titanium sinter, and detect the drum strength according to the standard requirements.

[0061] Those skilled in the art can routinely adjust the spacing of the above crusher, the number of dropping treatments, and the dropping height within a reasonable range.

[0062] In summary, the present invention provides some specific embodiments for preparing vanadium-titanium sinter, including the following steps:

[0063] Step 1: Oxidative roasting is carried out on the solid waste iron hydroxide mixture. Set the roasting temperature at 700 - 900 °C and the roasting time at 25 - 35 min to remove the crystal water and part of the chloride ions therein. At the same time, oxidize the iron and manganese elements in the iron hydroxide mixture into Fe 2 O 3 and MnO. After roasting is completed, carry out cooling and fine grinding. The mill is a ball medium cement mill, and the grinding time is determined according to the sample particle size. To ensure that the iron hydroxide mixture can be evenly distributed between the vanadium-titanium magnetite and quicklime, it is required that the proportion of the part with a particle size less than 0.074 mm after fine grinding is 40 - 60%. The roasted hydroxide is reserved for standby;

[0064] Step 2: Weigh the vanadium-titanium magnetite, activated ash and roasted iron hydroxide according to the batching principle of vanadium-titanium sinter index. The proportions of vanadium-titanium magnetite, activated ash and roasted iron hydroxide are 40 - 50%: 5 - 10%: 0 - 3% respectively. Then add this part of the material into a primary mixer for mixing for 4 - 6 min to prepare a uniform mixture 1;

[0065] Step 3: Then weigh other materials according to the established batching principle. The proportional relationship of domestic high-grade powder, domestic medium-grade powder, steel slag, limestone, coke powder and blast furnace return ore is 10 - 20%: 5 - 8%: 1 - 3%: 5 - 10%: 4 - 7%: 20 - 40%. Add this part of the material into the mixture 1 in sequence, and then mix for 4 - 6 min while spraying atomized water. The amount of atomized water added at this stage is 75 - 85% of the calculated total water volume to form a mixture 2 with an inlaid structure of mixture 1 and powder ore, fuel, flux and return ore;

[0066] Step 4: Then add the mixture 2 with an inlaid structure into a secondary mixer for granulation with water addition. The amount of water added at this stage is 15 - 25% of the calculated total water volume. Set the secondary mixing granulation time at 5 - 7 min to make the mixture 2 with an inlaid structure roll into balls evenly, ensuring that the part larger than 3 mm in the mixture 2 reaches 50 - 70%;

[0067] Step 5: Load the prepared mixture 2 into a sintering cup (diameter 300 mm, height 800 mm). The particle size of the bottom material in the sintering cup is 10 - 16 mm, the thickness of the bottom material is 15 - 25 mm, and the material layer thickness is in a sintering cup of 650 - 700 mm (including the thickness of the bottom material);

[0068] Step 6: Carry out ignition and suction sintering on the mixture in the sintering cup. The ignition temperature is 1100 - 1150 °C, the ignition time is 2.5 - 3.0 min, the ignition negative pressure is 5.5 - 6.0 kPa, the sintering suction negative pressure is 11.5 - 12.5 kPa, and the suction flow rate is 5 - 15 m 3 / min;

[0069] Step 7: When the waste gas temperature of the lower end exhaust duct of the sintering cup rises to the highest and then drops to 50 °C, the sintering process ends. Pour out the sintered cake and perform rough crushing (the spacing of the crusher is 50 mm), and then perform 3 dropping treatments (the dropping height is 2 m). After that, screen according to 40 - 25, 25 - 16, 16 - 10, 10 - 5, <5 mm, calculate the proportion of >5 mm, obtain the finished vanadium-titanium sinter, and test the drum strength according to the standard requirements.

[0070] The present invention tests the obtained finished vanadium-titanium sinter and finds that the drum strength of the sinter is above 59%, the sintering yield is above 70%, and the TFe grade of the sinter is above 49%. Compared with the finished vanadium-titanium sinter obtained without introducing ferric hydroxide calcine, the drum strength and sintering yield are increased by 1.6 - 4.3% and 0.8 - 1.8% respectively, and the TFe grade has no obvious change.

[0071] Therefore, the beneficial effects of the present invention compared with the prior art are as follows:

[0072] (1) By using oxidative roasting, the solid waste ferric hydroxide mixture undergoes a phase transformation. During the phase transformation, crystal water can be removed, the TFe content can be increased, and the TFe content of the sinter will not be affected after substitution.

[0073] (2) Through the step-by-step mixing operation, high-quality calcium ferrite bonding phase and low-melting-point MnO phase are preferentially added to the difficult-to-sinter vanadium-titanium magnetite, promoting the improvement of the quality of the sinter.

[0074] (3) Not only the organic elements iron and manganese in the secondary resources of the titanium dioxide chloride process are recycled, but also the pollution and damage of the solid waste ferric hydroxide mixture to the environment are reduced, with significant environmental protection benefits.

[0075] To further illustrate the present invention, the following detailed description is provided through the following examples.

[0076] The raw material ratios (calculated by weight percentage) involved in the examples and comparative examples are shown in Table 1 below:

[0077] Table 1

[0078]

[0079] The main physical and chemical indexes of the above-mentioned raw materials are (ω represents mass percentage):

[0080] Panzhihua concentrate ω(TFe) = 55.50%, ω(SiO 2 ) = 2.91%, ω(FeO) > 30%, ω(TiO 2 ) = 11.89%, ω(particle size less than 0.074 mm) > 90%;

[0081] For domestic high-grade powder, ω(TFe) = 58.02%, ω(SiO 2 ) = 3.69%, ω(CaO) = 2.04%;

[0082] For domestic medium-grade powder, ω(TFe) = 42.82%, ω(SiO 2 ) = 27.59%, ω(CaO) = 0.93%;

[0083] For the iron hydroxide mixture, ω(TFe) = 55.00%, ω(SiO 2 ) = 0.81%, ω(CaO) = 3.15%, ω(particle size less than 0.074mm) > 50%;

[0084] For activated ash, ω(CaO) is 85 - 90%, ω(particle size less than 0.074mm) > 80%;

[0085] For limestone, ω(CaO) is 50 - 55%, ω(particle size < 3.0mm) = 100%;

[0086] For coke powder, ash content is 12 - 15%, ω(particle size < 5.0mm) = 100%;

[0087] For returned ore, ω(TFe) is 49.50%, ω(SiO 2 ) is 5.0 - 5.5%, ω(CaO) is 11.0 - 12.0%, ω(particle size < 5mm) = 100%.

[0088] Example 1

[0089] This example provides a sintering method for an iron hydroxide mixture, which includes the following steps:

[0090] Step 1: Oxidative roasting is carried out on the solid waste iron hydroxide mixture. Set the roasting temperature at 800°C and the roasting time at 30 min. After roasting, cooling and fine grinding are carried out. The mill is a ball-type medium cement mill, and the grinding time is determined according to the sample particle size. To ensure that the iron hydroxide mixture can be evenly distributed between vanadium-titanium magnetite and quicklime, it is required that the proportion of the part with a particle size less than 0.074mm after fine grinding is about 50%. The roasted product of the hydroxide after fine grinding is reserved for later use;

[0091] Step 2: Weigh vanadium-titanium magnetite, activated ash and the finely ground roasted iron hydroxide according to the batching principle of vanadium-titanium sinter ore indicators. Among them, the ratios of vanadium-titanium magnetite, quicklime and the finely ground roasted iron hydroxide are shown in Table 1. Then add this part of the materials into a primary mixer for mixing. The mixing time is 4 min to prepare a uniform mixture 1;

[0092] Step 3: Then, weigh other materials according to the established batching principle. The ratios of domestic high-grade flour, domestic medium-grade flour, steel slag, limestone, coke powder, and blast furnace return ore are shown in Table 1. Add this part of the materials to the blended material 1 in sequence, and then mix for 4 minutes while spraying atomized water. The amount of atomized water added at this stage is 80% of the calculated total water volume (calculated based on 100 kg of dry basis, the total water volume is 13.77 kg, calculation formula: 100×0.075 / (1 - 0.075)+100×0.02×0.38+100×0.04×0.90 = 8.11 + 0.76 + 4.90 = 13.77 kg), forming a blended material 2 with an inlaid structure of powder ore, fuel, flux, and return ore;

[0093] Step 4: Add the blended material 2 with an inlaid structure to the secondary mixer for granulation with water addition. The amount of water added at this stage is 20% of the calculated total water volume. Set the secondary mixing granulation time to 6 minutes to make the blended material 2 with an inlaid structure roll into balls evenly, ensuring that more than 60% of the blended material is larger than 3 mm;

[0094] Step 5: Load the prepared blended material 2 into the sintering cup (diameter 300 mm, height 800 mm). The particle size of the bottom layer material for the sintering cup is 10 - 16 mm, the thickness of the bottom layer material is 20 mm, and the thickness of the material layer is 700 mm (including the thickness of the bottom layer material);

[0095] Step 6: Ignite and draw air for sintering the blended material 2 in the sintering cup. The ignition temperature is 1100°C - 1150°C, the ignition time is 3.0 minutes, the ignition negative pressure is 6.0 kPa, the sintering air extraction negative pressure is 12.0 kPa, and the air extraction flow rate is 10 m 3 / min;

[0096] Step 7: When the waste gas temperature at the lower end of the air extraction pipeline of the sintering cup rises to the highest and then drops to 50°C, the sintering process ends. Pour out the sintered cake and perform rough crushing (the spacing of the crusher is 50 mm), and then perform 3 times of dropping treatment (the dropping height is 2 m), and then screen according to 40 - 25 mm, 25 - 16 mm, 16 - 10 mm, 10 - 5 mm, <5 mm, calculate the proportion of >5 mm, and detect the drum strength according to the industry standard, YB / T 4605 - 2017.

[0097] The results show that the drum strength of the sinter is 59.13%, the sintering yield is 70.27%, the TFe grade of the sinter is 49.61%, the SiO 2 content is 5.44%, the CaO content is 11.59%, the TiO 2 content is 6.00%, the MnO content is 0.17%, and the sintering basicity CaO / SiO 2 = 2.13 times.

[0098] The above-mentioned sintering yield = the weight of the part greater than 5 mm divided by the total weight of the sintered cake × 100%.

[0099] Example 2

[0100] Carry out with reference to Example 1 and Table 1.

[0101] The results show that the drum strength of the sinter is 61.76%, the sintering yield is 71.18%, the TFe grade of the sinter is 49.60%, the SiO 2 content is 5.43%, the CaO content is 11.61%, the TiO 2 content is 5.93%, the MnO content is 0.20%, and the sintering basicity CaO / SiO 2 = 2.14 times.

[0102] Comparative Example 1

[0103] Carry out with reference to Example 1 and Table 1.

[0104] The results show that the drum strength of the sinter is 57.50%, the sintering yield is 69.46%, the TFe grade of the sinter is 49.62%, the SiO 2 content is 5.45%, the CaO content is 11.57%, the TiO 2 content is 6.07%, the MnO content is 0.14%, and the sintering basicity CaO / SiO 2 = 2.12 times.

[0105] In summary, Comparative Example 1 is a reference comparison experiment without adding a ferric hydroxide mixture. Examples 1 and 2 are experiments with 1% and 2% ferric hydroxide mixtures added. The yields and drum strengths of Examples 1 and 2 are significantly higher than those of Comparative Example 1.

[0106] It can be seen that the drum strength and yield of the vanadium-titanium sinter prepared by the method of the present invention are significantly improved. Moreover, as the yield increases, its processing cost is significantly reduced, which has significant economic benefits. At the same time, the solid waste ferric hydroxide mixture in the titanium dioxide chloride process is disposed of, which has obvious environmental benefits.

[0107] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be obvious to those skilled in the art. The general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to these embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for sintering a solid waste iron hydroxide mixture, characterized in that: The following steps are involved: The solid waste iron hydroxide mixture is subjected to oxidative roasting to obtain a roasted iron hydroxide product; The temperature of the oxidation roasting is 700-900°C.

2. The sintering method according to claim 1, characterized in that: The oxidation roasting time is 25 to 35 minutes.

3. The sintering method according to claim 1 or 2, characterized in that: After the oxidation roasting is completed, cooling and fine grinding are also included; After the fine grinding treatment, the proportion of the calcined iron hydroxide with a particle size of less than 0.074 mm is 40-60%.

4. Use of the calcined iron hydroxide obtained by the sintering method according to any one of claims 1 to 3 in the preparation of vanadium-titanium sintered ore.

5. A method for preparing vanadium-titanium sintered ore, characterized in that: The following steps are involved: S1: uniformly mixing vanadium-titanium magnetite, active ash and calcined iron hydroxide to obtain a first mixed material; S2: Evenly mix the powder ore, fuel, flux, return ore and the first mixed material to obtain a second mixed material; S3: Sintering the second mixed material to obtain vanadium-titanium sintered ore.

6. The preparation method according to claim 5, characterized in that: The mixing time in steps S1 and S2 is independently 2 to 10 minutes; After the sintering in step S3, coarse crushing, falling treatment and screening are also included in sequence.

7. The preparation method according to claim 5 or 6, characterized in that: The mass ratio of the vanadium-titanium magnetite, the active ash and the calcined iron hydroxide is (40-50):(5-10):(0-3).

8. The preparation method according to any one of claims 5 to 7, characterized in that The powder ore includes domestic high powder and domestic medium powder; The fuel includes coal powder and / or coke powder; The flux includes limestone and steel slag; The returned ore includes blast furnace returned ore; The mass ratio of the domestic high-grade powder, domestic medium-grade powder, steel slag, limestone, coke powder and blast furnace return ore is (10-20):(5-8):(1-3):(5-10):(4-7):(20-40).

9. The preparation method according to any one of claims 5 to 8, characterized in that: In step S2, atomized water is sprayed while mixing, and the amount of atomized water added is 75-85% of the total water amount calculated.

10. The preparation method according to claim 9, characterized in that: After the spraying of the atomized water is completed, water is added for granulation, and the amount of water added is 15-25% of the total water amount; The time for adding water to granulate is 3 to 10 minutes.

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