An aluminum-titanium-based composite bonding paste, its preparation method and application in fluorine-containing iron ore pellets

Abstract

The present invention discloses an aluminum-titanium-based composite bonding slurry, a preparation method thereof, and an application thereof in fluorine-containing iron ore pellets, and belongs to the technical field of solid waste resource utilization. The aluminum-titanium-based composite bonding slurry includes bauxite ore dressing tailings, vanadium-titanium ore dressing tailings, humic acid and water. The aluminum-titanium-based composite bonding slurry is used to replace the conventional binder of fluorine-containing iron ore pellets, which can improve the iron grade of fluorine-containing pellets and significantly improve the metallurgical properties of fluorine-containing pellets. In particular, the bauxite ore dressing tailings and vanadium-titanium ore dressing tailings in the composite bonding slurry are widely available, and resource utilization is achieved while treating solid waste. In addition, the preparation method of the composite bonding slurry is simple to operate, has low production cost, is environmentally friendly, and meets the requirements of industrialized production.

Description

Technical Field

[0001] The present invention relates to a bonding slurry, in particular to an aluminum-titanium-based composite bonding slurry, and also relates to a preparation method of the aluminum-titanium-based composite bonding slurry and its application in fluorine-containing iron ore pellets, belonging to the technical field of solid waste resource utilization. Background Art

[0002] As bulk solid waste resources from bauxite ore dressing tailings and vanadium-titanium ore dressing tailings, due to their huge output, rich in various valuable elements but with low comprehensive utilization rate, they are often treated by stacking.

[0003] At the same time, fluorine-containing iron ore, as a typical low-silicon, high-fluorine, and high-alkali metal mineral, has significant problems in pellet production. Due to the presence of fluorine and alkali metal elements, it not only reduces the compressive strength of the pellets, but also exacerbates the reduction swelling and deterioration of the melting drop performance, significantly limiting the application effect of fluorine-containing iron ore pellets in the blast furnace smelting process. This poses a great challenge to the application of this ore type in smelting, and it is urgent to solve these problems through technological improvement. In addition, bentonite, as a common binder, is widely used in the production of fluorine-containing iron ore pellets. However, the high addition amount of bentonite brings a series of new problems: on the one hand, it significantly increases the production cost; on the other hand, it greatly reduces the iron grade of the pellets, bringing negative impacts to blast furnace smelting.

[0004] To solve this technical bottleneck, in recent years, some studies have begun to try to use other binders, such as serpentine, etc., to replace bentonite to improve the metallurgical properties of fluorine-containing iron ore pellets. However, these alternative solutions also face limitations in practical applications, such as limited improvement effect, high cost, complex process, etc., and it is difficult to achieve large-scale promotion. Summary of the Invention

[0005] Aiming at the technical problems existing in the production process of existing fluorine-containing iron ore pellets, such as high binder consumption and poor metallurgical properties of the finished pellets, the first object of the present invention is to provide an aluminum-titanium-based composite bonding slurry, which can replace conventional fluorine-containing pellet binders, reduce the binder usage amount in the production process of fluorine-containing iron ore pellets, can significantly improve the strength and metallurgical properties of fluorine-containing iron ore pellets, and at the same time effectively utilize solid waste resources such as bauxite ore dressing tailings and vanadium-titanium ore dressing tailings, can relieve the environmental pressure brought by solid waste stacking, and also provide high-performance iron ore pellet raw materials for blast furnace smelting, promoting the sustainable utilization of resources and the progress of metallurgical technology.

[0006] The second object of the present invention is to provide a preparation method of the aluminum-titanium-based composite bonding slurry, which has simple operation and low raw material cost, and can meet the requirements of industrial production.

[0007] The third object of the present invention is to provide an application of an aluminum-titanium-based composite binder slurry in the preparation of fluorine-containing iron ore pellets. When it is used in the production process of fluorine-containing iron ore pellets, not only is the addition amount small and the binding effect excellent, but also the compressive strength and metallurgical properties of the pellets can be improved. At the same time, the resource utilization of beneficiation tailings is realized, and environmental pollution is reduced.

[0008] To achieve the above technical object, the present invention provides an aluminum-titanium-based composite binder slurry, which includes bauxite beneficiation tailings, vanadium-titanium ore beneficiation tailings, humic acid and water; the vanadium-titanium ore beneficiation tailings and the bauxite beneficiation tailings are composed according to a mass percentage of 20-80%:80-20%; the humic acid is 1-3% of the total mass of the vanadium-titanium ore beneficiation tailings and the bauxite beneficiation tailings; the water is measured at a solid-liquid mass ratio of 1:0.5-1.5.

[0009] In the aluminum-titanium-based composite binder slurry of the present invention, the sticky particles of bauxite beneficiation tailings and vanadium-titanium ore beneficiation tailings are tightly combined with humic acid, which can enhance the stability, adhesiveness and dispersion performance of the slurry, thereby significantly improving the green ball and dry ball strength of the pellets, reducing the addition amount of the binder. At the same time, the bauxite beneficiation tailings and vanadium-titanium ore beneficiation tailings can also provide Al 2 O 3 , TiO 2 , SiO 2 and other oxides, thereby improving the strength and melting drop performance of fluorine-containing iron ore pellets.

[0010] The main active components of the aluminum-titanium-based composite binder slurry of the present invention are the inorganic components composed of vanadium-titanium ore beneficiation tailings and bauxite beneficiation tailings and the organic component of humic acid. When the two are controlled within an appropriate proportion range, while ensuring excellent binding performance, the cost can be controlled and the pellet properties can be improved. Based on the synergistic effect of the active components in the two minerals of vanadium-titanium ore beneficiation tailings and bauxite beneficiation tailings, for example, the main components in bauxite beneficiation tailings are Al 2 O 3 and SiO 2 , the main components in vanadium-titanium ore beneficiation tailings are TiO 2 and SiO 2 . When the two are used in combination according to an appropriate proportion, the proportion range of these oxides can be adjusted to improve the binding effect of the composite binder and the metallurgical properties of the pellets.

[0011] As a more preferred scheme, the mass content of Al 2 O 3 in the bauxite beneficiation tailings is 10%-25%, and the mass content of SiO 2 is 30%-60%.

[0012] As a more preferred scheme, the TiO in the vanadium-titanium ore beneficiation tailings2 The mass content is 8% - 15%, SiO 2 The mass content is 35% - 50%.

[0013] An appropriate amount of SiO in the bauxite ore dressing tailings and vanadium-titanium ore dressing tailings of the present invention 2 can ensure that an appropriate amount of liquid phase is generated during the roasting process of the pellets to improve the strength of the oxidized pellets, while Al 2 O 3 and TiO 2 can ensure that the fluorine-containing iron ore pellets will not soften too quickly during the blast furnace smelting process to reduce the air permeability of the blast furnace, thereby obtaining good melting drop performance.

[0014] As a preferred embodiment, the particle sizes of the bauxite ore dressing tailings and the vanadium-titanium ore dressing tailings satisfy that the mass ratio of the -10 μm particle size fraction is more than 90%. The bauxite ore dressing tailings and the vanadium-titanium ore dressing tailings are ball-milled to an appropriate particle size. By using the activation effect of ball milling, not only the specific surface area of the bauxite ore dressing tailings and the vanadium-titanium ore dressing tailings can be increased, but also high activation energy can be imparted to them, thereby improving the synergistic effect between them and humic acid, enhancing the bonding performance of the composite binder, and at the same time, the reaction activity of the oxide components in the bauxite ore dressing tailings and the vanadium-titanium ore dressing tailings during the roasting process can be improved.

[0015] The present invention also provides a preparation method of an aluminum-titanium-based composite binder slurry. The method is to dry and ball-mill and activate the bauxite ore dressing tailings and the vanadium-titanium ore dressing tailings, and then mix them evenly with humic acid and water and perform ultrasonic treatment to obtain the slurry.

[0016] During the preparation process of the aluminum-titanium-based composite binder slurry provided by the present invention, the bauxite ore dressing tailings and the vanadium-titanium ore dressing tailings are activated by ball milling, which can improve the adsorption efficiency of humic acid on the surfaces of the bauxite ore dressing tailings and the vanadium-titanium ore dressing tailings particles. Especially under the action of ultrasonic waves, the dispersion degree of the bauxite ore dressing tailings and the vanadium-titanium ore dressing tailings particles can be improved, and at the same time, the uniform adsorption of the organic binder in the humic acid on the surfaces of the tailings particles can also be promoted, achieving a better modification effect.

[0017] As a preferred embodiment, the drying conditions are: the temperature is 200 - 300 °C, and the time is 180 - 250 min.

[0018] As a preferred embodiment, the ball milling and activation conditions are: the rotation speed is 250 - 300 revolutions / min, the time is 30 - 60 min, and the ball-to-material mass ratio is 2:1 - 5:1. The ball milling and activation process can increase the specific surface area of the bauxite ore dressing tailings and the vanadium-titanium ore dressing tailings, which is beneficial to the subsequent modification process.

[0019] As a preferred embodiment, the conditions for ultrasonic treatment are as follows: the temperature is 60 - 90 °C, the ultrasonic frequency is 25 - 30 KHz, and the ultrasonic time is 30 - 40 min. Under the preferred ultrasonic conditions, the high dispersibility of the bauxite ore dressing tailings and vanadium-titanium ore dressing tailings particles can be promoted, and the reactivity between humic acid and the bauxite ore dressing tailings and vanadium-titanium ore dressing tailings particles can be enhanced.

[0020] The present invention also provides an application of an aluminum-titanium-based composite binder slurry, which is used for preparing fluorine-containing iron ore pellets.

[0021] As a preferred embodiment, the aluminum-titanium-based composite binder slurry is sprayed on the fluorine-containing iron ore raw material and mixed evenly with water to form pellets. The obtained green pellets are subjected to roasting treatment to obtain the finished pellets.

[0022] As a preferred embodiment, the addition amount of the aluminum-titanium-based composite binder slurry in the fluorine-containing iron ore raw material is 0.8 - 1.5% of the dry basis mass of the fluorine-containing iron ore raw material. A small amount of the binder slurry can achieve a good binding effect, thereby reducing the usage amount of the binder and significantly improving the iron grade of the pellets.

[0023] As a preferred embodiment, the conditions for roasting are as follows: the temperature is 1250 - 1280 °C, and the time is 20 - 30 min. The selection of the roasting temperature plays an important role in the performance of the pellet ore. If the roasting temperature is too low or the time is too short, the strength of the roasted pellet ore is low and the metallurgical properties are poor. If the roasting temperature is too high or the time is too long, the strength of the pellet ore can be improved, but it will lead to an increase in energy consumption and production cost. Therefore, it is necessary to reasonably control the temperature and time during the roasting process to ensure that the compressive strength of the finished pellet ore reaches more than 2500 N, while the reduction expansion rate does not exceed 20%, and the temperature increase in the softening and melting range is not less than 50 °C.

[0024] Compared with the prior art, the beneficial technical effects brought by the technical solution of the present invention are as follows:

[0025] (1) The main components of the aluminum-titanium-based composite binder slurry of the present invention are the solid wastes of bauxite ore dressing tailings and vanadium-titanium ore dressing tailings. These two solid wastes are used as the inorganic binding components in the fluorine-containing iron ore pellet binder. They not only play a good binding role, but also are introduced as high melting point substances, which can improve the performance of the pellet ore. At the same time, it provides a new way for the utilization of bauxite ore dressing tailings and vanadium-titanium ore dressing tailings, reduces the discharge of waste residues, has good environmental friendliness, and meets the requirements of green production and circular economy.

[0026] (2) The aluminum-titanium-based composite binding slurry of the present invention combines bauxite ore dressing tailings, vanadium-titanium ore dressing tailings and humic acid for use, so as to replace traditional fluorine-containing iron ore pellet binders (such as bentonite, etc.). This not only reduces the addition amount of the binder in the pellets to improve the iron grade, but also can improve the strength and melting drop performance of the fluorine-containing iron ore pellets, which is beneficial to improving the subsequent blast furnace metallurgical performance.

[0027] (3) The preparation scheme of the aluminum-titanium-based composite binding slurry of the present invention is simple, low in cost and feasible in operation. Specific Embodiments

[0028] The following examples are intended to further illustrate the content of the present invention, rather than limiting the protection scope of the claims of the present invention.

[0029] In the following examples and comparative examples: the total iron grade of the fluorine-containing iron ore is 64%, the particle size composition of the raw material is that the mass ratio of the -0.074mm particle size grade is 92%, and the specific surface area is 820 cm 3 •g -1 .

[0030] In the following examples and comparative examples: the content of Al 2 O 3 in the bauxite ore dressing tailings is 21%, and the content of SiO 2 is 52%. The content of TiO 2 in the vanadium-titanium ore dressing tailings is 14%, and the content of SiO 2 is 42%. The particle sizes of the bauxite ore dressing tailings and the vanadium-titanium ore dressing tailings satisfy that the mass ratio of the -10 μm particle size grade is 95%.

[0031] Example 1

[0032] Mix the bauxite ore dressing tailings and the vanadium-titanium ore dressing tailings according to a mass ratio of 20:80. The mixed material is dried at 250 °C for 230 minutes. Then the dried material is ball-milled, the ball-to-material mass ratio is 3:1, the rotation speed is 280 revolutions / min, and the ball-milling time is 35 min. Mix the ball-milled material with 1.5% humic acid and water, the liquid-solid ratio is 1:0.9, and treat it under ultrasonic conditions of 80 °C and 30 kHz for 35 minutes to obtain the aluminum-titanium-based composite binding slurry. This slurry is sprayed onto the fluorine-containing iron ore at an addition ratio of 0.8%, mixed evenly and then pelletized, and after roasting at 1260 °C for 20 minutes, the finished pellet ore is obtained. The compressive strength of the obtained pellet ore is 2600 N, and the softening start temperature has increased by 54 °C compared with that without adding the composite binder.

[0033] Example 2

[0034] Mix bauxite ore dressing tailings and vanadium-titanium ore dressing tailings according to a mass ratio of 40:60. Dry the mixed material at 230 °C for 210 minutes. Then, perform ball milling on the dried material with a ball-to-material mass ratio of 4:1, a rotation speed of 275 revolutions / min, and a ball milling time of 50 min. Mix the ball-milled material with 1.5% humic acid and water, with a liquid-to-solid ratio of 1:1, and treat it under ultrasonic conditions of 75 °C and 28 kHz for 32 minutes to obtain an aluminum-titanium-based composite binder slurry. Spray the slurry onto fluorine-containing iron ore at an addition ratio of 1.3%, mix evenly, adjust the moisture to the appropriate pellet moisture, and perform pelletizing. After roasting at 1250 °C for 30 minutes, obtain the finished pellet ore. The compressive strength of the obtained pellet ore is 2550 N, and the softening start temperature increases by 52 °C compared to that without adding the composite binder.

[0035] Example 3

[0036] Mix bauxite ore dressing tailings and vanadium-titanium ore dressing tailings according to a mass ratio of 50:50. Dry the mixed material at 240 °C for 220 minutes. Then, perform ball milling on the dried material with a ball-to-material mass ratio of 3:1, a ball milling rotation speed of 260 revolutions / min, and a ball milling time of 35 min. Mix the ball-milled material with 1.5% humic acid and water, with a liquid-to-solid ratio of 1:1, and treat it under ultrasonic conditions of 70 °C and 25 kHz for 40 minutes to obtain an aluminum-titanium-based composite binder slurry. Spray the slurry onto fluorine-containing iron ore at an addition amount of 1.5%, mix evenly, perform pelletizing, and after roasting at a temperature of 1270 °C and a roasting time of 20 minutes, obtain the finished pellet ore. The compressive strength of the obtained pellet ore is 2650 N, and the softening start temperature increases by 60 °C compared to that without adding the composite binder.

[0037] Example 4

[0038] Mix bauxite ore dressing tailings and vanadium-titanium ore dressing tailings according to a mass ratio of 80:20. Dry the mixed material at 220 °C for 210 minutes. Then, perform ball milling on the dried material with a ball-to-material mass ratio of 3:1, a rotation speed of 295 revolutions / min, and a ball milling time of 60 min. Mix the ball-milled material with 1.5% humic acid and water, with a liquid-to-solid ratio of 1:1, and treat it under ultrasonic conditions of 70 °C and 28 kHz for 30 minutes to obtain an aluminum-titanium-based composite binder slurry. Spray the slurry onto fluorine-containing iron ore at an addition amount of 1.0%, mix evenly, perform pelletizing, and after roasting at 1250 °C for 25 minutes, obtain the finished pellet ore. The compressive strength of the obtained pellet ore is 2500 N, and the softening start temperature increases by 50 °C compared to that without adding the composite binder.

[0039] Comparative Example 1

[0040] Compared with Example 1, the only difference is that the finished pellet ore is obtained after roasting at 1230 °C for 20 minutes. Other process conditions refer to Example 1.

[0041] The results show that the compressive strength of the obtained pellet ore is 2342 N, and the softening start temperature has increased by 8 °C compared to that without adding the composite binder. Compared with Example 1, the roasting temperature has decreased by 30 °C, the compressive strength of the pellet ore has decreased by 258 N, and the softening start temperature has decreased by 46 °C, indicating that using this slurry at a lower roasting temperature is not conducive to improving the pellet strength.

[0042] Comparative Example 2

[0043] Compared with Example 2, the only difference is that the slurry is sprayed onto the fluorine-containing iron ore at an addition ratio of 0.4%. Other process conditions refer to Example 2.

[0044] The results show that the compressive strength of the obtained pellet ore is 2435 N, and the softening start temperature has increased by 25 °C compared to that without adding the composite binder. Compared with Example 2, although the process conditions are the same, due to the lower addition ratio of the slurry, it reduces the compactness of the pellets and the content of high-melting-point substances in the pellets (Al 2 O 3 and TiO 2 ), which has an adverse effect on the improvement of the strength and softening start temperature of the pellet ore. The compressive strength has decreased by 115 N, and the softening start temperature has decreased by 27 °C.

[0045] Comparative Example 3

[0046] Compared with Example 3, the only difference is that a single vanadium-titanium ore dressing tailing or a single bauxite ore dressing tailing is used to replace the mixture of bauxite ore dressing tailing and vanadium-titanium ore dressing tailing in Example 3 at a mass ratio of 50:50. Other process conditions refer to Example 3.

[0047] The results show that:

[0048] When using a single vanadium-titanium ore dressing tailing, the compressive strength of the obtained pellet ore is 2480 N, and the softening start temperature has increased by 45 °C compared to that without adding the composite binder.

[0049] When using a single bauxite ore dressing tailing, the compressive strength of the obtained pellet ore is 2530 N, and the softening start temperature has increased by 35 °C compared to that without adding the composite binder.

[0050] Using a single vanadium-titanium ore dressing tailing or a single bauxite ore dressing tailing is not conducive to improving the pellet strength and the initial softening temperature.

[0051] Comparative Example 4

[0052] Compared with Example 4, the only difference is that the dried material is ball-milled with a ball-to-material mass ratio of 3:1, a rotation speed of 295 revolutions per minute, and a ball-milling time of 20 minutes. Other process conditions refer to Example 4.

[0053] The compressive strength of the obtained pellet ore is 2410 N, and the softening start temperature has increased by 40 °C compared to that without adding the composite binder. Compared with Example 4, the ball-milling time of the slurry is shortened by 10 minutes, the compressive strength of the pellet ore decreases by 90 N, and the softening start temperature decreases by 10 °C, indicating that using a shorter ball-milling time is not conducive to the activation of tail mud, resulting in a reduction in pellet properties.

Claims

1. An aluminum-titanium based composite bonding slurry, characterized in that: Including bauxite beneficiation tailings, vanadium-titanium ore beneficiation tailings, humic acid and water; The vanadium-titanium ore dressing tailings and the bauxite ore dressing tailings are composed of 20-80%:80-20% by mass; The humic acid is 1-3% of the total mass of the vanadium-titanium ore dressing tailings and the bauxite ore dressing tailings; The water is measured at a solid-to-liquid mass ratio of 1:0.5-1.

5.

2. The aluminum-titanium based composite bonding slurry according to claim 1, characterized in that: The Al2O3 mass content in the bauxite beneficiation tailings is 10% to 25%, and the SiO2 mass content is 30% to 60%; The mass content of TiO2 in the vanadium-titanium ore dressing tailings is 8% to 15%, and the mass content of SiO2 is 35% to 50%; The particle size of the bauxite beneficiation tailings and the vanadium-titanium ore beneficiation tailings meets the -10 μm particle size, and the mass proportion of the tailings is more than 90%.

3. The method for preparing an aluminum-titanium based composite adhesive slurry according to claim 1 or 2, characterized in that: The bauxite beneficiation tailings and vanadium-titanium ore beneficiation tailings are dried and ball-milled for activation, then evenly mixed with humic acid and water and subjected to ultrasonic treatment to obtain the product.

4. The method for preparing an aluminum-titanium based composite adhesive slurry according to claim 3, characterized in that: The drying conditions are: temperature of 200-300°C and time of 180-250 min; The conditions for ball milling activation are: a rotation speed of 250-300 rpm, a time of 30-60 min, and a ball-to-material mass ratio of 2:1-5:

1.

5. The method for preparing an aluminum-titanium based composite adhesive slurry according to claim 3, characterized in that: The ultrasonic treatment conditions are: temperature of 60-90° C., ultrasonic frequency of 25-30 KHz, and ultrasonic time of 30-40 min.

6. The use of an aluminum-titanium based composite adhesive slurry according to claim 1 or 2, characterized in that: Used to prepare fluorine-containing iron ore pellets.

7. The use of an aluminum-titanium based composite bonding slurry according to claim 6, characterized in that: The aluminum-titanium based composite bonding slurry is sprayed on the fluorine-containing iron ore raw material and water is added to mix evenly to form balls. The obtained raw balls are calcined to obtain finished balls.

8. The use of an aluminum-titanium based composite bonding slurry according to claim 7, characterized in that: The amount of the aluminum-titanium based composite adhesive slurry added to the fluorine-containing iron ore raw material is 0.8-1.5% of the dry basis mass of the fluorine-containing iron ore raw material.

9. The use of an aluminum-titanium based composite bonding slurry according to claim 7, characterized in that: The calcination conditions are as follows: temperature of 1250-1280° C. and time of 20-30 min.