A method and apparatus for efficient deep grinding of vanadium-titanium magnetite

Abstract

This application discloses a method and apparatus for efficient deep grinding of vanadium-titanium magnetite, relating to the field of mineral processing technology. The method includes: heating the vanadium-titanium magnetite to be ground using a microwave heating device; after microwave heating, the metallic minerals inside the ore rapidly absorb heat, increasing the thermal stress difference between the metallic and non-metallic minerals and reducing the grinding difficulty; then using a vacuum water quenching device to cool the vanadium-titanium magnetite, forming cracks inside the ore, and water molecules entering these cracks under negative pressure; then using a negative pressure circulating liquid nitrogen quick-freezing device to cool and freeze the vanadium-titanium magnetite, causing the water in the cracks inside the ore to freeze and expand, creating internal expansion pressure that further develops the internal cracks; and finally using a high-pressure roller mill to perform ultrafine grinding of the vanadium-titanium magnetite, further developing the internal cracks, reducing the Bond work index of the ore, and simultaneously reducing the particle size, thus reducing the difficulty of mineral liberation and grinding energy consumption during the grinding process.

Description

Technical Field

[0001] This application relates to the field of mineral processing technology, and in particular to a method and apparatus for efficient deep crushing and grinding of vanadium-titanium magnetite. Background Technology

[0002] The Panxi region is rich in vanadium-titanium magnetite resources. In the ore beneficiation and crushing process, the traditional "three-stage and closed-circuit" crushing process is mainly used to crush the ore to below 15-20mm. In the ore beneficiation operation, grinding energy consumption accounts for about 80% of the entire beneficiation industry. Because the useful minerals and gangue minerals in the Panxi vanadium-titanium magnetite are densely coexisting, the liberation process is difficult and energy consumption is high.

[0003] Therefore, how to reduce the difficulty of mineral liberation and grinding energy consumption during the grinding process is a problem that needs to be solved by those skilled in the art. Summary of the Invention

[0004] The purpose of this application is to provide a method and apparatus for efficient deep grinding of vanadium-titanium magnetite, which can solve the problems of high difficulty in the liberation of various minerals and high energy consumption during the grinding process.

[0005] To address the aforementioned technical problems, this application provides a method for efficient deep grinding of vanadium-titanium magnetite, comprising:

[0006] A microwave heating device was used to heat the vanadium-titanium magnetite to be ground.

[0007] The temperature difference and the actual water temperature of the vacuum water quenching device are obtained. The target heating temperature is obtained based on the temperature difference and the actual water temperature. It is then determined whether the temperature of the vanadium-titanium magnetite to be ground has reached the target heating temperature. The temperature difference is the difference between the temperature of the vanadium-titanium magnetite to be ground and the water temperature in the vacuum water quenching device, and the temperature difference is sufficient to cause cracks in the vanadium-titanium magnetite to be ground.

[0008] If the temperature of the vanadium-titanium magnetite to be ground reaches the target heating temperature, the vanadium-titanium magnetite to be ground after heat treatment is cooled by vacuum water quenching using a vacuum water quenching device.

[0009] After the vanadium-titanium magnetite to be ground is cooled to room temperature, the room temperature vanadium-titanium magnetite to be ground is cooled and frozen using a negative pressure circulating liquid nitrogen quick-freezing device.

[0010] The cooled and frozen vanadium-titanium magnetite was subjected to ultrafine crushing using a high-pressure roller mill.

[0011] In one feasible embodiment, after the cooled and frozen vanadium-titanium magnetite is subjected to ultrafine crushing using a high-pressure roller mill, the process further includes:

[0012] After the ultrafine crushed vanadium-titanium magnetite is dispersed, it is screened by a high-frequency vibrating screen to obtain oversize material with a particle size greater than 2mm and undersize material with a particle size less than 2mm. The oversize material with a particle size greater than 2mm is returned to the high-pressure roller mill for circulating roller crushing.

[0013] Grinding equipment is used to grind and dissociate undersize particles smaller than 2 mm.

[0014] In one feasible embodiment, before the microwave heating device is used to heat the vanadium-titanium magnetite to be ground, the process further includes:

[0015] The vanadium-titanium magnetite ore is subjected to coarse crushing, medium crushing and fine crushing in sequence to obtain vanadium-titanium magnetite ore to be ground with a particle size of less than 15 mm.

[0016] In one feasible embodiment, the step of sequentially crushing the vanadium-titanium magnetite ore into coarse, medium, and fine particles to obtain vanadium-titanium magnetite ore to be ground with a particle size of less than 15 mm includes:

[0017] Jaw crushers or gyratory crushers are used to coarsely crush vanadium-titanium magnetite ore.

[0018] A cone crusher is used to perform medium crushing on the coarsely crushed vanadium-titanium magnetite ore.

[0019] The crushed vanadium-titanium magnetite ore is screened to obtain undersize material with a particle size of less than 15 mm and oversize material with a particle size of more than 15 mm.

[0020] The vanadium-titanium magnetite ore with a particle size greater than 15 mm is finely crushed using a fine crusher. The crushed vanadium-titanium magnetite ore is then screened. The vanadium-titanium magnetite ore with a particle size greater than 15 mm is returned to the fine crusher for further crushing. The undersize ore with a particle size less than 15 mm is collected as the vanadium-titanium magnetite ore to be ground.

[0021] In one feasible embodiment, the heating treatment of the vanadium-titanium magnetite to be ground using a microwave heating device includes:

[0022] Adjust the frequency, power, and irradiation time of the microwave heating device to heat the vanadium-titanium magnetite to be ground to 300-400℃.

[0023] In one feasible embodiment, it further includes:

[0024] Record the heating time and temperature of the microwave heating device, the vacuum water quenching cooling time of the vacuum water quenching device, and the cooling and freezing time of the negative pressure circulating liquid nitrogen quick-freezing device.

[0025] This application also provides an apparatus for efficient deep grinding of vanadium-titanium magnetite, applied to the method of efficient deep grinding of vanadium-titanium magnetite, including...

[0026] A microwave heating device is used for heating vanadium-titanium magnetite to be ground.

[0027] Vacuum water quenching device is used to cool down vanadium-titanium magnetite that has been heated.

[0028] The negative pressure circulating liquid nitrogen quick-freezing device is used to cool and freeze vanadium-titanium magnetite ore to be ground at room temperature.

[0029] High-pressure roller mills are used for ultrafine crushing of vanadium-titanium magnetite ore after it has been cooled and frozen.

[0030] In one feasible embodiment, the microwave heating device includes a microwave generator, a microwave cavity, and a microwave local shield. The microwave generator is connected to the microwave cavity via a waveguide, and the microwave local shield is disposed inside the microwave cavity. The microwave local shield is used to control the irradiation area of ​​the microwave.

[0031] In one feasible embodiment, the microwave cavity is provided with a temperature measuring device and a rotating stirrer, and the side wall of the microwave cavity is provided with a ventilation window made of a metal honeycomb panel.

[0032] In one feasible embodiment, the negative pressure circulating liquid nitrogen quick-freezing device includes a liquid nitrogen supply device, a quick-freezing chamber, a liquid nitrogen evaporator, a cryogenic fan, and a vacuum pump. The liquid nitrogen evaporator is located at the bottom of the quick-freezing chamber, the liquid nitrogen supply device is connected to the liquid nitrogen evaporator, the cryogenic fan is located inside the quick-freezing chamber and above the liquid nitrogen evaporator, the cryogenic fan is used to circulate the air inside the quick-freezing chamber, and the vacuum pump is connected to the quick-freezing chamber.

[0033] This application provides a method for efficient deep grinding of vanadium-titanium magnetite, comprising: heating the vanadium-titanium magnetite to be ground using a microwave heating device; obtaining the temperature difference and the actual water temperature of a vacuum water quenching device, obtaining a target heating temperature based on the temperature difference and the actual water temperature, and determining whether the temperature of the vanadium-titanium magnetite to be ground has reached the target heating temperature; wherein, the temperature difference is the difference between the temperature of the vanadium-titanium magnetite to be ground and the water temperature in the vacuum water quenching device, and the temperature difference is sufficient to cause cracks in the vanadium-titanium magnetite to be ground; if the temperature of the vanadium-titanium magnetite to be ground reaches the target heating temperature, vacuum water quenching is performed on the heated vanadium-titanium magnetite to be ground; after the vanadium-titanium magnetite to be ground is cooled to room temperature, a negative pressure circulating liquid nitrogen quick-freezing device is used to cool and freeze the room temperature vanadium-titanium magnetite to be ground; and ultrafine grinding of the cooled and frozen vanadium-titanium magnetite to be ground is performed using a high-pressure roller mill. The vanadium-titanium magnetite to be ground undergoes a series of treatments: microwave heating, vacuum water quenching, liquid nitrogen immersion freezing, and high-pressure roller milling for ultrafine crushing. Microwave heating causes the metallic minerals inside the ore to absorb heat rapidly, increasing the thermal stress difference between the metallic and non-metallic minerals, which effectively reduces the grinding difficulty of the ore. Then, vacuum water quenching cools the ore, creating fissures inside and allowing water molecules to enter these fissures under negative pressure. Liquid nitrogen immersion then rapidly cools and freezes the ore, causing the water in the fissures to freeze and expand, creating internal expansion pressure that further develops the internal fissures. Finally, high-pressure roller milling further develops the internal fissures of the ore particles, reducing the Bond work index and particle size. This reduces the difficulty of mineral liberation and grinding energy consumption, thereby improving grinding efficiency.

[0034] The beneficial effects and methods of the device for efficient deep grinding of vanadium-titanium magnetite provided in this application are as described above. Attached Figure Description

[0035] To more clearly illustrate the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0036] Figure 1 A flowchart of a method for efficient deep grinding of vanadium-titanium magnetite provided in this application embodiment;

[0037] Figure 2 A flowchart of another method for efficient deep grinding of vanadium-titanium magnetite provided in this application embodiment;

[0038] Figure 3 This is a structural diagram of an apparatus for efficient deep grinding of vanadium-titanium magnetite, provided in an embodiment of this application. Detailed Implementation

[0039] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of this application.

[0040] The core of this application is to provide a method and apparatus for efficient deep grinding of vanadium-titanium magnetite, which reduces the particle size of the product entering the mill from the front end, while using auxiliary measures to reduce the interfacial interaction force between metallic and non-metallic minerals, reduce the Bond work index of the ore, and reduce the dissociation difficulty of each mineral and grinding energy consumption during the grinding process.

[0041] To enable those skilled in the art to better understand the present application, the present application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0042] Figure 1 A flowchart of a method for efficient deep grinding of vanadium-titanium magnetite provided in this application embodiment is shown below. Figure 1 As shown, the method for efficient deep grinding of vanadium-titanium magnetite includes:

[0043] S10: Use a microwave heating device to heat the vanadium-titanium magnetite to be ground.

[0044] S11: Obtain the temperature difference and the actual water temperature of the vacuum water quenching device, obtain the target heating temperature based on the temperature difference and the actual water temperature, and determine whether the temperature of the vanadium-titanium magnetite to be ground has reached the target heating temperature; wherein, the temperature difference is the difference between the temperature of the vanadium-titanium magnetite to be ground and the water temperature in the vacuum water quenching device, and the temperature difference can cause cracks to be generated in the vanadium-titanium magnetite to be ground.

[0045] S12: If the temperature of the vanadium-titanium magnetite to be ground reaches the target heating temperature, the vanadium-titanium magnetite to be ground after heat treatment is cooled by vacuum water quenching using a vacuum water quenching device.

[0046] S13: After the vanadium-titanium magnetite to be ground is cooled to room temperature, the vanadium-titanium magnetite to be ground at room temperature is cooled and frozen using a negative pressure circulating liquid nitrogen quick-freezing device.

[0047] S14: Use a high-pressure roller mill to perform ultrafine crushing on the cooled and frozen vanadium-titanium magnetite.

[0048] Before step S10, the process further includes: sequentially crushing the vanadium-titanium magnetite ore into coarse, medium, and fine particles to obtain vanadium-titanium magnetite ore to be ground with a particle size of less than 15 mm. Specifically, a jaw crusher or gyratory crusher is used to coarsely crush the vanadium-titanium magnetite ore; a cone crusher is used to medium crush the coarsely crushed vanadium-titanium magnetite ore; the medium-crushed vanadium-titanium magnetite ore is screened to obtain undersize material with a particle size of less than 15 mm and oversize material with a particle size of greater than 15 mm; a fine crusher is used to finely crush the oversize material with a particle size of greater than 15 mm; the finely crushed vanadium-titanium magnetite ore is screened, and the oversize material with a particle size of greater than 15 mm is returned to the fine crusher for recycling and fine crushing, while the undersize material with a particle size of less than 15 mm is collected as the vanadium-titanium magnetite ore to be ground. The fine crusher can be a short-head cone crusher. Coarse crushing is a stage in the crushing process, which refers to the process of breaking large pieces of material into smaller pieces through mechanical force; medium crushing is a stage in the crushing process, which refers to the second stage of crushing after the first stage of crushing; fine crushing refers to the process of crushing materials into finer particle sizes. A fine crusher is a piece of equipment specifically designed for fine crushing operations. It can crush materials into smaller particle sizes to meet the requirements of subsequent processes.

[0049] In step S10, the vanadium-titanium magnetite to be ground, with a particle size of less than 15 mm produced by coarse, medium, and fine crushing, is fed into a high-power microwave heating device for rapid heating. Specifically, the frequency, power, and irradiation time of the microwave heating device can be adjusted to heat the vanadium-titanium magnetite to the target heating temperature of 300-400℃. Previous studies have shown that the microwave absorption capacity of metallic minerals in vanadium-titanium magnetite is significantly higher than that of non-metallic minerals. Therefore, by increasing the thermal stress difference between metallic and non-metallic minerals, the grinding difficulty of the ore can be effectively reduced.

[0050] In step S11, the temperature difference can be the difference between the temperature of the vanadium-titanium magnetite to be ground, which is determined by multiple experiments to enable cracks to form in the heated vanadium-titanium magnetite after rapid cooling, and the water temperature in the vacuum water quenching device. Based on the temperature difference and the actual water temperature of the vacuum water quenching device, the target heating temperature of the vanadium-titanium magnetite to be ground can be determined, thereby controlling the microwave heating device to heat the vanadium-titanium magnetite to be ground to the target heating temperature, so as to ensure that cracks can form inside the ore after the vacuum water quenching device cools the heated vanadium-titanium magnetite to be ground.

[0051] In step S13, the vanadium-titanium magnetite to be ground, which has been cooled to room temperature by vacuum water quenching, is fed into a negative pressure circulating liquid nitrogen quick-freezing device, so that the ore is immersed in liquid nitrogen for rapid cooling and freezing for 5-15 minutes.

[0052] In step S14, ultrafine crushing is a processing technique that allows materials to achieve a finer particle size.

[0053] Furthermore, it also includes recording the heating time and temperature of the microwave heating device, the vacuum water quenching cooling time of the vacuum water quenching device, and the cooling and freezing time of the negative pressure circulating liquid nitrogen quick-freezing device, in order to facilitate subsequent analysis and quality control.

[0054] This application provides a method for efficient deep grinding of vanadium-titanium magnetite, comprising: heating the vanadium-titanium magnetite to be ground using a microwave heating device; obtaining the temperature difference and the actual water temperature of a vacuum water quenching device, obtaining a target heating temperature based on the temperature difference and the actual water temperature, and determining whether the temperature of the vanadium-titanium magnetite to be ground has reached the target heating temperature; wherein, the temperature difference is the difference between the temperature of the vanadium-titanium magnetite to be ground and the water temperature in the vacuum water quenching device, and the temperature difference is sufficient to cause cracks in the vanadium-titanium magnetite to be ground; if the temperature of the vanadium-titanium magnetite to be ground reaches the target heating temperature, vacuum water quenching is performed on the heated vanadium-titanium magnetite to be ground to cool it down; after the vanadium-titanium magnetite to be ground is cooled to room temperature, a negative pressure circulating liquid nitrogen quick-freezing device is used to cool and freeze the room temperature vanadium-titanium magnetite to be ground; and ultrafine grinding is performed on the cooled and frozen vanadium-titanium magnetite to be ground using a high-pressure roller mill. The vanadium-titanium magnetite to be ground undergoes a series of treatments: microwave heating, vacuum water quenching, liquid nitrogen immersion freezing, and high-pressure roller milling for ultrafine crushing. Microwave heating causes the metallic minerals inside the ore to absorb heat rapidly, increasing the thermal stress difference between the metallic and non-metallic minerals, which effectively reduces the grinding difficulty of the ore. Then, vacuum water quenching cools the ore, creating fissures inside and allowing water molecules to enter these fissures under negative pressure. Liquid nitrogen immersion then rapidly cools and freezes the ore, causing the water in the fissures to freeze and expand, creating internal expansion pressure that further develops the internal fissures. Finally, high-pressure roller milling further develops the internal fissures of the ore particles, reducing the Bond work index and particle size, thereby reducing the difficulty of mineral liberation and grinding energy consumption, and improving grinding efficiency.

[0055] Based on the above embodiments, Figure 2 A flowchart of another method for efficient deep grinding of vanadium-titanium magnetite provided in this application embodiment is shown below. Figure 2 As shown, the method for efficient deep grinding of vanadium-titanium magnetite includes:

[0056] S20: Use a microwave heating device to heat the vanadium-titanium magnetite to be ground.

[0057] S21: Obtain the temperature difference and the actual water temperature of the vacuum water quenching device, obtain the target heating temperature based on the temperature difference and the actual water temperature, and determine whether the temperature of the vanadium-titanium magnetite to be ground has reached the target heating temperature; wherein, the temperature difference is the difference between the temperature of the vanadium-titanium magnetite to be ground and the water temperature in the vacuum water quenching device, and the temperature difference can cause cracks to be generated in the vanadium-titanium magnetite to be ground.

[0058] S22: If the temperature of the vanadium-titanium magnetite to be ground reaches the target heating temperature, the vanadium-titanium magnetite to be ground after heat treatment is cooled by vacuum water quenching using a vacuum water quenching device.

[0059] S23: After the vanadium-titanium magnetite to be ground is cooled to room temperature, the vanadium-titanium magnetite to be ground at room temperature is cooled and frozen using a negative pressure circulating liquid nitrogen quick-freezing device.

[0060] S24: Use a high-pressure roller mill to perform ultrafine crushing on the cooled and frozen vanadium-titanium magnetite.

[0061] S25: After the ultrafine crushed vanadium-titanium magnetite is dispersed, it is screened by a high-frequency vibrating screen to obtain oversize material with a particle size greater than 2mm and undersize material with a particle size less than 2mm. The oversize material with a particle size greater than 2mm is returned to the high-pressure roller mill for circulating roller crushing.

[0062] S26: Grinding and dissociating undersize particles smaller than 2 mm using grinding equipment.

[0063] Since steps S20 to S24 have been described in the previous embodiment, they will not be repeated here.

[0064] In step S25, the vanadium-titanium magnetite is ultrafine crushed to achieve a smaller particle size, preparing for subsequent screening and grinding. Since the ultrafinely crushed ore may form lumps or aggregates, it needs to be broken up for screening. A high-pressure roller mill is used to crush the ore under high pressure, improving crushing efficiency and reducing energy consumption. In step S26, the grinding equipment includes ball mills, rod mills, autogenous mills, and semi-autogenous mills. In the ball mill, steel or ceramic balls rotate with the mill, impacting and grinding the ore to further liberate it.

[0065] To gain a more intuitive understanding of the effects of "microwave heating + vacuum water quenching + liquid nitrogen immersion quick-freezing + high-pressure roller mill ultrafine crushing" on vanadium-titanium magnetite, several sets of comparative experiments are introduced below.

[0066] The chemical composition of the vanadium-titanium iron concentrate sample used in the experiment is shown in Table 1 below.

[0067] Table 1. Chemical composition analysis results of vanadium-titanium magnetite ore samples / %

[0068]

[0069] Experiment 1

[0070] (1) The vanadium-titanium magnetite to be ground with a particle size of less than 15 mm is divided into two equal parts by the quartering method.

[0071] (2) One portion of vanadium-titanium magnetite with a particle size of less than 15 mm is fed into a high-power pulsed microwave heating device for rapid heating treatment to raise the ore temperature to 300-320℃; then, the ore after pulsed microwave heating is rapidly fed into a vacuum water quenching device for vacuum water quenching and cooling to room temperature of 20-25℃; subsequently, the ore cooled to room temperature by vacuum water quenching is fed into a negative pressure circulating liquid nitrogen quick-freezing device, so that the ore is immersed in liquid nitrogen for rapid cooling and freezing for 5-7 minutes. n; Subsequently, the ore, after being quick-frozen by soaking in liquid nitrogen, is fed into a high-pressure roller mill for ultrafine crushing. The ultrafine crushed ore is then dispersed and screened using a high-frequency vibrating screen to obtain oversize material with a particle size greater than 2 mm and undersize material with a particle size less than 2 mm. The oversize material is returned to the high-pressure roller mill for circulating roller crushing. Finally, the crushed ore (undersize material) is fed into a ball mill and ground and liberated for 3 minutes at a grinding concentration of 67% to obtain grinding product A.

[0072] (3) Another batch of raw ore with a particle size of less than 15 mm is crushed to less than 2 mm by a crusher and then fed into a ball mill for grinding and dissociation for 3 min under the condition of grinding concentration of 67% to obtain grinding product B.

[0073] (4) Use a sieve with a mesh size of 0.074 mm to screen product A and product B respectively, and count the weight ratio of particles larger than 0.074 mm on the sieve and particles smaller than 0.074 mm on the sieve.

[0074] The results showed that the proportion of particles smaller than 0.074 mm in product A increased by 4.78 percentage points compared to product B.

[0075] Experiment 2

[0076] (1) The vanadium-titanium magnetite to be ground with a particle size of less than 15 mm is divided into two equal parts by the quartering method.

[0077] (2) One portion of vanadium-titanium magnetite with a particle size of less than 15 mm is fed into a high-power pulsed microwave heating device for rapid heating to raise the ore temperature to 340-360℃; then, the ore after pulsed microwave heating is rapidly fed into a vacuum water quenching device for vacuum water quenching and cooling to room temperature of 20-25℃; subsequently, the ore cooled to room temperature by vacuum water quenching is fed into a negative pressure circulating liquid nitrogen quick-freezing device, so that the ore is immersed in liquid nitrogen for rapid cooling and freezing for 9-11 minutes. min; then, the ore, after being quick-frozen by soaking in liquid nitrogen, is fed into a high-pressure roller mill for ultrafine crushing. The ultrafine crushed ore is then dispersed and screened using a high-frequency vibrating screen to obtain oversize material with a particle size greater than 2 mm and undersize material with a particle size less than 2 mm. The oversize material is returned to the high-pressure roller mill for circulating roller crushing. Finally, the crushed ore (undersize material) is fed into a ball mill and ground and liberated for 5 min at a grinding concentration of 67% to obtain grinding product A.

[0078] (3) Another batch of vanadium-titanium magnetite with a particle size of less than 15 mm is crushed to less than 2 mm by a crusher and then fed into a ball mill for grinding and dissociation for 5 min under the condition of grinding concentration of 67% to obtain grinding product B.

[0079] (4) Use a sieve with a mesh size of 0.074 mm to screen product A and product B respectively, and count the weight ratio of particles larger than 0.074 mm on the sieve and particles smaller than 0.074 mm on the sieve.

[0080] The results showed that the proportion of particles smaller than 0.074 mm in product A increased by 6.35 percentage points compared to product B.

[0081] Experiment 3

[0082] (1) The vanadium-titanium magnetite to be ground with a particle size of less than 15 mm is divided into two equal parts by the quartering method.

[0083] (2) One portion of vanadium-titanium magnetite with a particle size of less than 15 mm is fed into a high-power pulsed microwave heating device for rapid heating treatment to raise the ore temperature to 380-400℃; then, the ore after pulsed microwave heating is rapidly fed into a vacuum water quenching device for vacuum water quenching and cooling to room temperature of 20-25℃; subsequently, the ore cooled to room temperature by vacuum water quenching is fed into a negative pressure circulating liquid nitrogen quick-freezing device, so that the ore is immersed in liquid nitrogen for rapid cooling and freezing for 14-15 minutes. Subsequently, the ore, after being quick-frozen by soaking in liquid nitrogen, is fed into a high-pressure roller mill for ultrafine crushing. The ultrafine crushed ore is then dispersed and screened using a high-frequency vibrating screen to obtain oversize material with a particle size greater than 2 mm and undersize material with a particle size less than 2 mm. The oversize material is returned to the high-pressure roller mill for circulating roller crushing. Finally, the crushed ore (undersize material) is fed into a ball mill and ground and dissociated for 7 minutes at a grinding concentration of 67% to obtain grinding product A.

[0084] (3) Another batch of raw ore with a particle size of less than 15 mm is crushed to less than 2 mm by a crusher and then fed into a ball mill for grinding and dissociation for 7 min under the condition of grinding concentration of 67% to obtain grinding product B.

[0085] (4) Use a sieve with a mesh size of 0.074 mm to screen product A and product B respectively, and count the weight ratio of particles larger than 0.074 mm on the sieve and particles smaller than 0.074 mm on the sieve.

[0086] The results showed that the proportion of particles smaller than 0.074 mm in product A increased by 7.72 percentage points compared to product B.

[0087] Based on the above embodiments, Figure 3 A structural diagram of an apparatus for efficient deep grinding of vanadium-titanium magnetite provided in this application embodiment is shown below. Figure 3 As shown, the device for efficient deep grinding of vanadium-titanium magnetite includes:

[0088] Microwave heating device 10 is used to heat the vanadium-titanium magnetite to be ground.

[0089] Vacuum water quenching device 11 is used to cool down vanadium-titanium magnetite that has been heated by vacuum water quenching.

[0090] The negative pressure circulating liquid nitrogen quick-freezing device 12 is used to cool and freeze vanadium-titanium magnetite to be ground at room temperature.

[0091] High-pressure roller mill 13 is used for ultrafine crushing of vanadium-titanium magnetite ore after cooling and freezing.

[0092] Of course, it may also include a control device connected to the microwave heating device 10, the vacuum water quenching device 11, the negative pressure circulating liquid nitrogen quick-freezing device 12 and the high pressure roller mill 13 respectively, the control device being used to execute the steps in the method of efficient deep crushing and grinding of vanadium-titanium magnetite.

[0093] The microwave heating device includes a microwave generator, a microwave cavity, and a microwave local shield. The microwave generator is connected to the microwave cavity via a waveguide, and the microwave local shield is located inside the microwave cavity to control the microwave irradiation area. In practical applications, the microwaves generated by the microwave generator enter the microwave cavity through the waveguide and are then evenly distributed within the cavity. Controlled by the microwave local shield, the microwave energy is precisely transferred to the ore to be heated. This design allows for point-to-point or directional heating of the ore while ensuring the uniformity and controllability of the heating process. Furthermore, the microwave cavity is equipped with a temperature measuring device and a rotary stirrer, and the side walls of the microwave cavity have ventilation windows made of metal honeycomb panels. The temperature measuring device monitors the temperature inside the microwave cavity to ensure the controllability of the heating process; the rotary stirrer ensures the uniform distribution of microwave energy in the ore; and the ventilation windows or ventilation walls made of metal honeycomb panels ensure unobstructed airflow inside and outside the microwave cavity while shielding the microwaves.

[0094] The negative pressure circulating liquid nitrogen quick-freezing device includes a liquid nitrogen supply unit, a quick-freezing chamber, a liquid nitrogen evaporator, a cryogenic fan, and a vacuum pump. The liquid nitrogen evaporator is located at the bottom of the quick-freezing chamber, and the liquid nitrogen supply unit is connected to it. The cryogenic fan is located inside the quick-freezing chamber and above the liquid nitrogen evaporator, circulating air within the chamber. The vacuum pump is connected to the quick-freezing chamber. The liquid nitrogen supply unit includes a liquid nitrogen tank and a transfer pump, which is connected to both the tank and the evaporator. The liquid nitrogen tank is located outside the quick-freezing chamber and stores liquid nitrogen. The quick-freezing chamber is the core component of the device, typically constructed with heat-insulating materials and equipped with internal material racks for quick-freezing. The liquid nitrogen evaporator, located at the bottom of the chamber, vaporizes the liquid nitrogen, absorbing heat from the surrounding environment to achieve the freezing effect. The cryogenic fan, located above the evaporator, circulates air within the chamber, improving heat exchange efficiency. The vacuum pump maintains a negative pressure environment within the chamber, further enhancing freezing efficiency.

[0095] This application provides an efficient deep crushing and grinding apparatus for vanadium-titanium magnetite, comprising: a microwave heating device for heating the vanadium-titanium magnetite to be ground; a vacuum water quenching device for quenching and cooling the heated vanadium-titanium magnetite; a negative pressure circulating liquid nitrogen quick-freezing device for cooling and freezing the vanadium-titanium magnetite at room temperature; and a high-pressure roller mill for ultra-fine crushing the cooled and frozen vanadium-titanium magnetite. The vanadium-titanium magnetite to be ground undergoes a series of treatments: microwave heating, vacuum water quenching, liquid nitrogen immersion freezing, and high-pressure roller milling for ultrafine crushing. Microwave heating causes the metallic minerals inside the ore to absorb heat rapidly, increasing the thermal stress difference between the metallic and non-metallic minerals, which effectively reduces the grinding difficulty of the ore. Then, vacuum water quenching cools the ore, creating fissures inside and allowing water molecules to enter these fissures under negative pressure. Liquid nitrogen immersion then rapidly cools and freezes the ore, causing the water in the fissures to freeze and expand, creating internal expansion pressure that further develops the internal fissures. Finally, high-pressure roller milling further develops the internal fissures of the ore particles, reducing the Bond work index and particle size, thereby reducing the difficulty of mineral liberation and grinding energy consumption, and improving grinding efficiency.

[0096] The above provides a detailed description of a method and apparatus for efficient deep grinding of vanadium-titanium magnetite provided in this application. The various embodiments in the specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since it corresponds to the method disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to in the method section. It should be noted that those skilled in the art can make several improvements and modifications to this application without departing from the principles of this application, and these improvements and modifications also fall within the protection scope of the claims of this application.

[0097] It should also be noted that, in this specification, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

Claims

1. A method for high-efficiency deep crushing of vanadium-titanium magnetite, characterized in that, The application relates to a method for preparing vanadium-titanium magnetite. The method comprises the following steps: heating the vanadium-titanium magnetite to be ground by using a microwave heating device; obtaining a temperature difference and an actual water temperature of a vacuum water quenching device, obtaining a target heating temperature according to the temperature difference and the actual water temperature, and judging whether the temperature of the vanadium-titanium magnetite to be ground reaches the target heating temperature; wherein the temperature difference is the difference between the temperature of the vanadium-titanium magnetite to be ground and the water temperature in the vacuum water quenching device, and the temperature difference can cause the vanadium-titanium magnetite to be ground to generate cracks; if the temperature of the vanadium-titanium magnetite to be ground reaches the target heating temperature, the vanadium-titanium magnetite to be ground after the heating treatment is quenched by using the vacuum water quenching device; after the vanadium-titanium magnetite to be ground is cooled to normal temperature, the vanadium-titanium magnetite to be ground at normal temperature is cooled and frozen by using a negative pressure circulating liquid nitrogen quick-freezing device; the vanadium-titanium magnetite to be ground after the cooling and freezing is superfine crushed by using a high-pressure roller mill; the microwave heating device comprises a microwave generator, a microwave cavity and a microwave local shielding element, the microwave generator is connected with the microwave cavity through a waveguide tube, the microwave local shielding element is arranged in the microwave cavity, and the microwave local shielding element is used for controlling the irradiation area of microwaves; a temperature measuring device and a rotary stirrer are arranged in the microwave cavity, and a ventilation window composed of a metal honeycomb plate is arranged on the side wall of the microwave cavity. After the vanadium-titanium magnetite to be ground after the cooling and freezing is superfine crushed by using the high-pressure roller mill, the method further comprises the following steps: the vanadium-titanium magnetite to be ground after the superfine crushing is scattered and sieved by using a high-frequency vibrating screen to obtain oversize materials with a particle size greater than 2 mm and undersize materials with a particle size less than 2 mm, and the oversize materials with a particle size greater than 2 mm are returned to the high-pressure roller mill for cyclic roller pressing and crushing; the undersize materials with a particle size less than 2 mm are ground and dissociated by using a grinding device. Before the vanadium-titanium magnetite to be ground is heated by using the microwave heating device, the method further comprises the following steps: the vanadium-titanium magnetite ore is sequentially coarsely crushed, medium crushed and finely crushed to obtain the vanadium-titanium magnetite to be ground with a particle size less than 15 mm. The vanadium-titanium magnetite ore is sequentially coarsely crushed, medium crushed and finely crushed to obtain the vanadium-titanium magnetite to be ground with a particle size less than 15 mm, and the method comprises the following steps: the vanadium-titanium magnetite ore is coarsely crushed by using a jaw crusher or a gyratory crusher; the coarsely crushed vanadium-titanium magnetite ore is medium crushed by using a cone crusher; the medium crushed vanadium-titanium magnetite ore is sieved to obtain undersize materials with a particle size less than 15 mm and oversize materials with a particle size greater than 15 mm; the oversize materials with a particle size greater than 15 mm are finely crushed by using a fine crusher, the finely crushed vanadium-titanium magnetite ore is sieved, the oversize materials with a particle size greater than 15 mm are returned to the fine crusher for cyclic fine crushing, and the undersize materials with a particle size less than 15 mm are collected as the vanadium-titanium magnetite to be ground. The method for heating the vanadium-titanium magnetite to be ground by using the microwave heating device comprises the following steps: the frequency, power and irradiation time of the microwave heating device are regulated and controlled, and the vanadium-titanium magnetite to be ground is heated to 300-400 DEG C. The method further comprises the following steps: the heating time and heating temperature of the microwave heating device, the vacuum water quenching time of the vacuum water quenching device and the cooling and freezing time of the negative pressure circulating liquid nitrogen quick-freezing device are recorded. ​ 2. The method for high-efficient and deep grinding of vanadium-titanium magnetite according to claim 1, characterized in that, ​ ​ ​ 3. The method for high-efficient and deep grinding of vanadium titano-magnetite according to claim 1, characterized in that, ​ ​ 4. The method of high-efficient and deep comminution of vanadium titano-magnetite according to claim 3, characterized in that, ​ ​ ​ ​ ​ 5. The method of high-efficient deep crushing and grinding of vanadium titano-magnetite according to claim 1, characterized in that, ​ ​ 6. The method for high-efficient and deep grinding of vanadium titano-magnetite according to claim 1, characterized in that, ​ ​ 7. A device for high-efficiency deep crushing of vanadium-titanium magnetite, characterized in that it comprises: The application is applied to the method for high-efficiency and deep crushing of vanadium-titanium magnetite as claimed in any one of claims 1 to 6, and comprises the following steps: a microwave heating device for heating the vanadium-titanium magnetite to be ground; a vacuum water quenching device for quenching the vanadium-titanium magnetite to be ground after the heating treatment; a negative pressure circulating liquid nitrogen quick-freezing device for cooling and freezing the vanadium-titanium magnetite to be ground at normal temperature; a high-pressure roller mill for ultra-finely crushing the vanadium-titanium magnetite to be ground after the cooling and freezing; the microwave heating device comprises a microwave generator, a microwave cavity and a microwave local shielding part, the microwave generator is connected with the microwave cavity through a waveguide, the microwave local shielding part is arranged in the microwave cavity, and the microwave local shielding part is used for controlling the irradiation area of the microwave; a temperature measuring device and a rotary stirrer are arranged in the microwave cavity, and the side wall of the microwave cavity is provided with a ventilation window composed of a metal honeycomb plate.

8. The apparatus for high-efficient deep crushing and grinding of vanadium-titanium magnetite according to claim 7, characterized in that, the negative pressure circulating liquid nitrogen quick-freezing device comprises a liquid nitrogen supply device, a quick-freezing box, a liquid nitrogen evaporator, a low-temperature fan and a vacuum pump, the liquid nitrogen evaporator is arranged at the bottom of the quick-freezing box, the liquid nitrogen supply device is connected with the liquid nitrogen evaporator, the low-temperature fan is arranged in the quick-freezing box and located above the liquid nitrogen evaporator, the low-temperature fan is used for circulating the air in the quick-freezing box, and the vacuum pump is connected with the quick-freezing box.

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