Method and device for efficiently and deeply grinding vanadium titano-magnetite

Abstract

The invention discloses a method and device for efficient deep crushing and grinding of vanadium titano-magnetite, and relates to the technical field of mineral processing.The method comprises the steps that the vanadium titano-magnetite to be ground is heated through a microwave heating device, after microwave heating, metal minerals in the ore rapidly absorb heat, and the thermal stress difference between the metal minerals and non-metal minerals is increased; the ore grinding difficulty is reduced; then vacuum water quenching cooling is conducted on the vanadium titano-magnetite to be ground through a vacuum water quenching device, cracks are formed in the ore, and water molecules enter the cracks in the ore under the action of negative pressure; cooling and freezing the vanadium titano-magnetite to be ground by using a negative-pressure circulating liquid nitrogen quick-freezing device, and after water in internal cracks of the ore becomes ice, performing volume expansion to form internal expansion pressure to further develop the internal cracks; the high-pressure roller mill is used for carrying out ultrafine crushing on the vanadium titano-magnetite to be ground, internal cracks of the ore are further developed, the Bond power index of the ore is reduced, meanwhile, the particle size of the ore is reduced, and the dissociation difficulty of all minerals and the ore grinding energy consumption in the ore grinding process are reduced.

Description

Technical Field

[0001] The present application relates to the technical field of mineral processing, and in particular to a method and device for high-efficiency deep grinding of vanadium-titanium magnetite. Background Art

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

[0003] Therefore, how to reduce the difficulty of dissociation of various minerals and the energy consumption of grinding during the grinding process is a problem that technical personnel in this field need to solve. Summary of the invention

[0004] The purpose of the present application is to provide a method and device for high-efficiency deep grinding of vanadium-titanium magnetite, which is used to solve the problems of difficulty in dissociation of various minerals and high energy consumption during the grinding process.

[0005] In order to solve the above technical problems, the present application provides a method for high-efficiency deep grinding of vanadium-titanium magnetite, comprising:

[0006] The vanadium-titanium magnetite to be ground is heated by using a microwave heating device;

[0007] Obtaining the temperature difference and the actual water temperature of the vacuum water quenching device, obtaining the 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 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, a vacuum water quenching device is used to perform vacuum water quenching and cooling on the vanadium-titanium magnetite to be ground after the heating treatment;

[0009] 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 vanadium-titanium magnetite to be ground at room temperature;

[0010] The vanadium-titanium magnetite to be ground is ultra-finely crushed by a high-pressure roller mill after being cooled and frozen.

[0011] In a feasible embodiment, after the high pressure roller mill is used to ultra-finely crush the cooled and frozen vanadium-titanium magnetite to be ground, the method further comprises:

[0012] The ultra-finely crushed vanadium-titanium magnetite to be ground is broken up and sieved by a high-frequency vibrating screen machine to obtain the oversize with a particle size greater than 2 mm and the undersize with a particle size less than 2 mm, and the oversize with a particle size greater than 2 mm is returned to the high-pressure roller mill for cyclic roller crushing;

[0013] Grinding equipment is used to grind and separate the undersize material with a particle size of less than 2 mm.

[0014] In a feasible embodiment, before the heating treatment of the vanadium-titanium magnetite to be ground by the microwave heating device, the method further comprises:

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

[0016] In a feasible embodiment, the vanadium-titanium magnetite ore is subjected to coarse crushing, medium crushing and fine crushing in sequence to obtain the vanadium-titanium magnetite to be ground with a particle size of less than 15 mm, comprising:

[0017] The vanadium-titanium magnetite ore is coarsely crushed by a jaw crusher or a gyratory crusher;

[0018] The cone crusher is used to perform secondary crushing on the vanadium-titanium magnetite ore after coarse crushing;

[0019] The vanadium-titanium magnetite ore after medium crushing is screened to obtain undersize with a particle size of less than 15 mm and oversize with a particle size of greater than 15 mm;

[0020] The sieve material with a particle size greater than 15 mm is crushed by a fine crusher, the crushed vanadium-titanium magnetite ore is screened, the sieve material with a particle size greater than 15 mm is returned to the fine crusher for cyclic fine crushing, and the sieve material with a particle size less than 15 mm is collected as the vanadium-titanium magnetite to be ground.

[0021] In a feasible embodiment, the method of heating the vanadium-titanium magnetite to be ground by using a microwave heating device comprises:

[0022] The frequency, power and irradiation time of the microwave heating device are adjusted to heat the vanadium-titanium magnetite to be ground to 300-400°C.

[0023] In a feasible embodiment, it also 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] The present application also provides a device for high-efficiency deep grinding of vanadium-titanium magnetite, which is applied to the method for high-efficiency deep grinding of vanadium-titanium magnetite, comprising:

[0026] A microwave heating device is used to heat the vanadium-titanium magnetite to be ground;

[0027] A vacuum water quenching device is used to perform vacuum water quenching and cooling on the vanadium-titanium magnetite to be ground after the heating treatment;

[0028] Negative pressure circulating liquid nitrogen quick freezing device, used to cool and freeze the vanadium-titanium magnetite to be ground at room temperature;

[0029] The high pressure roller mill is used to ultra-finely crush the vanadium-titanium magnetite to be ground after being cooled and frozen.

[0030] In a feasible embodiment, the microwave heating device includes a microwave generator, a microwave cavity and a microwave local shielding component, the microwave generator is connected to the microwave cavity through a waveguide tube, the microwave local shielding component is arranged in the microwave cavity, and the microwave local shielding component is used to control the irradiation area of ​​the microwave.

[0031] In a feasible embodiment, a temperature measuring device and a rotary stirrer are provided in the microwave cavity, and a ventilation window composed of a metal honeycomb panel is provided on the side wall of the microwave cavity.

[0032] In a feasible embodiment, the negative pressure circulating liquid nitrogen quick freezing device includes 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 to the liquid nitrogen evaporator, the low-temperature fan is arranged in the quick freezing box and is located above the liquid nitrogen evaporator, the low-temperature fan is used to circulate the air in the quick freezing box, and the vacuum pump is connected to the quick freezing box.

[0033] The present application provides a method for high-efficiency deep crushing of vanadium-titanium magnetite, comprising: using a microwave heating device to heat the vanadium-titanium magnetite to be ground; obtaining the temperature difference and the 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 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, using a vacuum water quenching device to cool the vanadium-titanium magnetite to be ground after the heating treatment; after the vanadium-titanium magnetite to be ground is cooled to room temperature, using a negative pressure circulating liquid nitrogen quick-freezing device to cool and freeze the vanadium-titanium magnetite to be ground at room temperature; and using a high-pressure roller mill to ultra-finely crush the cooled and frozen vanadium-titanium magnetite to be ground. The vanadium-titanium magnetite to be ground is sequentially treated with "microwave heating + vacuum water quenching + liquid nitrogen immersion quick freezing + high-pressure roller grinding ultra-fine crushing". After microwave heating, the metal minerals inside the ore absorb heat quickly, increasing the thermal stress difference between metal minerals and non-metallic minerals, which can effectively reduce the difficulty of grinding the ore; then, vacuum water quenching is used to form cracks inside the ore, and water molecules enter the cracks inside the ore under negative pressure, and then the ore is quickly cooled and frozen by liquid nitrogen immersion. After the water in the cracks inside the ore turns into ice, its volume expands to form internal expansion pressure, which further develops the internal cracks, and then high-pressure roller grinding is used to further develop the internal cracks of the ore particles, thereby reducing the ore Bond work index and further reducing the particle size of the ore particles, thereby reducing the difficulty of dissociation of various minerals and the energy consumption of grinding during the grinding process, and improving the crushing efficiency.

[0034] The beneficial effects of the device for efficient deep grinding of vanadium-titanium magnetite provided in the present application correspond to the method, and the effects are as above. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0036] FIG1 is a flow chart of a method for high-efficiency deep grinding of vanadium-titanium magnetite provided in an embodiment of the present application;

[0037] FIG2 is a flow chart of another method for high-efficiency deep grinding of vanadium-titanium magnetite provided in an embodiment of the present application;

[0038] FIG3 is a structural diagram of a device for high-efficiency deep grinding of vanadium-titanium magnetite provided in an embodiment of the present application. DETAILED DESCRIPTION

[0039] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0040] The core of this application is to provide a method and device for efficient deep grinding of vanadium-titanium magnetite, which is used to reduce the particle size of the product entering the mill from the front end, and at the same time use auxiliary measures to reduce the interfacial interaction force between metal minerals and non-metallic minerals, reduce the Bond work index of the ore, and reduce the difficulty of dissociation of various minerals in the grinding process and the grinding energy consumption.

[0041] In order to enable those skilled in the art to better understand the present application, the present application is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0042] FIG1 is a flow chart of a method for high-efficiency deep grinding of vanadium-titanium magnetite provided in an embodiment of the present application. As shown in FIG1 , the method for high-efficiency deep grinding of vanadium-titanium magnetite includes:

[0043] S10: using 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 according to the temperature difference and the actual water temperature, and judge 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 cracks 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, a vacuum water quenching device is used to perform vacuum water quenching and cooling on the vanadium-titanium magnetite to be ground after the heating treatment.

[0046] S13: 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 vanadium-titanium magnetite to be ground at room temperature.

[0047] S14: using a high pressure roller mill to ultra-finely crush the cooled and frozen vanadium-titanium magnetite to be ground.

[0048] Before step S10, the method further includes: coarsely crushing, medium crushing and fine crushing the vanadium-titanium magnetite ore in sequence to obtain the vanadium-titanium magnetite ore to be ground with a particle size of less than 15 mm, specifically, using a jaw crusher or a gyratory crusher to coarsely crush the vanadium-titanium magnetite ore; using a cone crusher to medium crush the coarsely crushed vanadium-titanium magnetite ore; screening the vanadium-titanium magnetite ore after medium crushing to obtain undersize with a particle size of less than 15 mm and oversize with a particle size of greater than 15 mm; using a fine crusher to finely crush the oversize with a particle size of greater than 15 mm, screening the vanadium-titanium magnetite ore after fine crushing, returning the oversize with a particle size of greater than 15 mm to the fine crusher for cyclic fine crushing, and collecting the undersize with a particle size of less than 15 mm as the vanadium-titanium magnetite to be ground. Among them, the fine crusher can be a short-head cone crusher. Coarse crushing is a stage in the pulverizing 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 pulverizing process, which refers to the second stage of crushing after the material has been crushed in the first stage; fine crushing refers to the process of crushing the material into smaller particles. The fine crusher is a device specially used for fine crushing operations. It can crush the material into smaller particles 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 crushing, medium crushing and fine crushing is fed into a high-power microwave heating device for rapid heating treatment. Specifically, the frequency, power and irradiation time of the microwave heating device can be adjusted to heat the vanadium-titanium magnetite to a target heating temperature of 300-400° C. Existing studies have shown that the wave absorption capacity of metal minerals in vanadium-titanium magnetite is significantly higher than that of non-metallic minerals. Therefore, by increasing the thermal stress difference between metal minerals and non-metallic minerals, the difficulty of grinding 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 and the water temperature in the vacuum water quenching device, which is determined based on multiple experiments and can cause cracks in the heated vanadium-titanium magnetite after rapid cooling; the target heating temperature of the vanadium-titanium magnetite to be ground can be determined based on the temperature difference and the actual water temperature of the vacuum water quenching device, so as to control the microwave heating device to heat the vanadium-titanium magnetite to be ground to the target heating temperature, so as to ensure as much as possible that cracks can be formed inside the ore after the vacuum water quenching device performs vacuum water quenching and cooling on the vanadium-titanium magnetite to be ground after the heating treatment.

[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 and rapidly cooled and frozen for 5-15 minutes.

[0052] In step S14, ultra-fine crushing is a processing technology that allows the material to reach a finer particle size.

[0053] Furthermore, it also includes: recording the heating time and heating 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, so as to facilitate subsequent analysis and quality control.

[0054] A method for efficient deep crushing of vanadium-titanium magnetite provided in an embodiment of the present application comprises: using a microwave heating device to heat the vanadium-titanium magnetite to be ground; obtaining the temperature difference and the 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 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, using a vacuum water quenching device to cool the vanadium-titanium magnetite to be ground after the heating treatment; after the vanadium-titanium magnetite to be ground is cooled to room temperature, using a negative pressure circulating liquid nitrogen quick-freezing device to cool and freeze the vanadium-titanium magnetite to be ground at room temperature; and using a high-pressure roller mill to ultra-finely crush the cooled and frozen vanadium-titanium magnetite to be ground. The vanadium-titanium magnetite to be ground is sequentially treated with "microwave heating + vacuum water quenching + liquid nitrogen immersion quick freezing + high-pressure roller grinding ultra-fine crushing". After microwave heating, the metal ore inside the ore absorbs heat quickly, increasing the thermal stress difference between metal minerals and non-metallic minerals, which can effectively reduce the difficulty of grinding the ore; then, vacuum water quenching is used to form cracks inside the ore, and water molecules enter the cracks inside the ore under negative pressure, and then the ore is quickly cooled and frozen by liquid nitrogen immersion. After the water in the cracks inside the ore turns into ice, its volume expands to form internal expansion pressure, which further develops the internal cracks, and then high-pressure roller grinding is used to further develop the internal cracks of the ore particles, reducing the ore Bond work index, and at the same time further reducing the particle size of the ore particles, thereby reducing the difficulty of dissociation of various minerals and the energy consumption of grinding during the grinding process, and improving the crushing efficiency.

[0055] Based on the above embodiment, FIG2 is a flow chart of another method for high-efficiency deep grinding of vanadium-titanium magnetite provided in an embodiment of the present application. As shown in FIG2, the method for high-efficiency deep grinding of vanadium-titanium magnetite includes:

[0056] S20: using 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 according to the temperature difference and the actual water temperature, and judge 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 cracks 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, a vacuum water quenching device is used to perform vacuum water quenching and cooling on the vanadium-titanium magnetite to be ground after the heating treatment.

[0059] S23: 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 vanadium-titanium magnetite to be ground at room temperature.

[0060] S24: Using a high pressure roller mill to ultra-finely crush the cooled and frozen vanadium-titanium magnetite to be ground.

[0061] S25: After the ultra-finely crushed vanadium-titanium magnetite to be ground is broken up, it is sieved by a high-frequency vibrating screen to obtain an oversize material with a particle size greater than 2 mm and an undersize material with a particle size less than 2 mm, and the oversize material with a particle size greater than 2 mm is returned to the high-pressure roller mill for cyclic roller crushing.

[0062] S26: Grind and separate the undersize material with a particle size less than 2 mm using a grinding device.

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

[0064] In step S25, the vanadium-titanium magnetite is ultra-finely crushed to achieve a smaller particle size in preparation for subsequent screening and grinding. Since the ultra-finely crushed ore may form lumps or aggregates, it needs to be broken up for screening. The high-pressure roller mill is used to crush the ore under high pressure to improve the crushing efficiency and reduce energy consumption. In step S26, the grinding equipment includes a ball mill, a rod mill, an autogenous mill and a semi-autogenous mill, etc., wherein the steel balls or ceramic balls in the ball mill rotate with the mill to impact and grind the ore to achieve further dissociation of the ore.

[0065] In order to have a more intuitive understanding of the effect of "microwave heating + vacuum water quenching + liquid nitrogen immersion quick freezing + high-pressure roller grinding ultra-fine crushing" treatment on the vanadium-titanium magnetite to be ground, several groups of control 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] Test 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 quartering.

[0071] (2) A portion of the vanadium-titanium magnetite to be ground with a particle size of less than 15 mm is fed into a high-power pulse microwave heating device for rapid heating to raise the temperature of the ore to 300-320°C; secondly, the ore after pulse microwave heating is quickly fed into a vacuum water quenching device for vacuum water quenching to cool it down to room temperature of 20-25°C; then, 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 and rapidly cooled and frozen for 5-7 minutes. n; Subsequently, the ore after quick freezing by immersion in liquid nitrogen is fed into a high-pressure roller mill for ultra-fine crushing, and the ultra-finely crushed ore is broken up and sieved by a high-frequency vibrating screen to obtain an oversize material with a particle size greater than 2 mm and an undersize material with a particle size less than 2 mm, and the oversize material is returned to the high-pressure roller mill for cyclic roller crushing; Finally, the crushed ore (undersize material) is fed into a ball mill for grinding and dissociation for 3 minutes at a grinding concentration of 67%, to obtain a grinding product A.

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

[0073] (4) Use a sieve with a mesh size of 0.074 mm to sieve Product A and Product B respectively, and calculate the weight percentage of particles larger than 0.074 mm on the sieve and particles less than 0.074 mm under the sieve.

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

[0075] Test 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 quartering.

[0077] (2) A portion of the vanadium-titanium magnetite to be ground with a particle size of less than 15 mm is fed into a high-power pulse microwave heating device for rapid heating to raise the temperature of the ore to 340-360°C; secondly, the ore after pulse microwave heating is quickly fed into a vacuum water quenching device for vacuum water quenching to cool it down to room temperature of 20-25°C; then, 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 and rapidly cooled and frozen for 9-11 seconds. min; then, the ore after quick freezing by immersion in liquid nitrogen is fed into a high-pressure roller mill for ultra-fine crushing, and the ultra-finely crushed ore is broken up and sieved by a high-frequency vibrating screen to obtain an oversize material with a particle size greater than 2 mm and an undersize material less than 2 mm, and the oversize material is returned to the high-pressure roller mill for cyclic roller crushing; finally, the crushed ore (undersize material) is fed into a ball mill for grinding and dissociation for 5 minutes at a grinding concentration of 67%, to obtain a grinding product A.

[0078] (3) Another portion of vanadium-titanium magnetite to be ground with a particle size of less than 15 mm was crushed to less than 2 mm by a crusher, and then fed into a ball mill for grinding and dissociation at a grinding concentration of 67% for 5 minutes to obtain grinding product B.

[0079] (4) Use a sieve with a mesh size of 0.074 mm to sieve Product A and Product B respectively, and calculate the weight percentage of particles larger than 0.074 mm on the sieve and particles less than 0.074 mm under the sieve.

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

[0081] Test 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 quartering.

[0083] (2) A portion of the vanadium-titanium magnetite to be ground with a particle size of less than 15 mm is fed into a high-power pulse microwave heating device for rapid heating to raise the temperature of the ore to 380-400°C; secondly, the ore after pulse microwave heating is quickly fed into a vacuum water quenching device for vacuum water quenching to cool it down to room temperature of 20-25°C; then, 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 and rapidly cooled and frozen for 14-15 minutes. in; then, the ore after quick freezing by immersion in liquid nitrogen is fed into a high-pressure roller mill for ultra-fine crushing, and the ultra-fine crushed ore is broken up and sieved by a high-frequency vibrating screen to obtain an oversize material with a particle size greater than 2 mm and an undersize material with a particle size less than 2 mm, and the oversize material is returned to the high-pressure roller mill for cyclic roller crushing; finally, the crushed ore (undersize material) is fed into a ball mill for grinding and dissociation for 7 minutes at a grinding concentration of 67%, to obtain a grinding product A.

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

[0085] (4) Use a sieve with a mesh size of 0.074 mm to sieve Product A and Product B respectively, and calculate the weight percentage of particles larger than 0.074 mm on the sieve and particles less than 0.074 mm under the sieve.

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

[0087] Based on the above embodiment, FIG3 is a structural diagram of a device for high-efficiency deep grinding of vanadium-titanium magnetite provided in an embodiment of the present application. As shown in FIG3, the device for high-efficiency deep grinding of vanadium-titanium magnetite includes:

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

[0089] The vacuum water quenching device 11 is used to perform vacuum water quenching and cooling on the vanadium-titanium magnetite to be ground after the heating treatment.

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

[0091] The high pressure roller mill 13 is used for ultra-finely crushing the cooled and frozen vanadium-titanium magnetite to be ground.

[0092] Of course, it can 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, and the control device is used to execute the steps in the method of efficient deep grinding of vanadium-titanium magnetite.

[0093] The microwave heating device includes a microwave generator, a microwave cavity and a microwave local shielding member. The microwave generator is connected to the microwave cavity through a waveguide tube. The microwave local shielding member is arranged in the microwave cavity. The microwave local shielding member is used to control the irradiation area of ​​the microwave. In practical applications, the microwaves generated by the microwave generator enter the microwave cavity through the waveguide tube and are then evenly distributed in the microwave cavity. Through the control of the microwave local shielding member, the microwave energy is accurately transmitted to the ore to be heated. This design allows the ore to be heated at a fixed point or in a directional manner while ensuring the uniformity and controllability of the heating process. Furthermore, a temperature measuring device and a rotary stirrer are arranged in the microwave cavity, and a ventilation window composed of a metal honeycomb panel is arranged on the side wall of the microwave cavity. A temperature measuring device is used to monitor the temperature in the microwave cavity to ensure the controllability of the heating process; a rotary stirrer is used to ensure the uniform distribution of microwave energy in the ore; a ventilation window or ventilation wall composed of a metal honeycomb panel is used to ensure that the airflow inside and outside the microwave cavity is unobstructed while shielding the microwave.

[0094] The negative pressure circulating liquid nitrogen quick freezing device includes a liquid nitrogen supply device, a quick freezing box, a liquid nitrogen evaporator, a cryogenic 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 to the liquid nitrogen evaporator, the cryogenic fan is arranged in the quick freezing box and located above the liquid nitrogen evaporator, the cryogenic fan is used to circulate the air in the quick freezing box, and the vacuum pump is connected to the quick freezing box. The liquid nitrogen supply device includes a liquid nitrogen tank and a delivery pump, the delivery pump is connected to the liquid nitrogen tank and the liquid nitrogen evaporator respectively, and the liquid nitrogen tank is placed outside the quick freezing box for storing liquid nitrogen. The quick freezing box is the core part of the device, which usually adopts heat insulation and thermal insulation materials, and is provided with a material bracket inside, and the material is placed on the bracket for quick freezing. The liquid nitrogen evaporator is located at the bottom of the quick freezing box, which is used to gasify liquid nitrogen and achieve the freezing effect by absorbing the surrounding heat. The cryogenic fan is located above the liquid nitrogen evaporator, which is used to circulate the air in the quick freezing box to improve the heat exchange efficiency. The vacuum pump is used to maintain the negative pressure environment in the quick freezing box to improve the freezing efficiency.

[0095] The embodiment of the present application provides a device for high-efficiency deep crushing of vanadium-titanium magnetite, comprising: a microwave heating device for heating the vanadium-titanium magnetite to be ground; a vacuum water quenching device for vacuum water quenching and cooling 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 room temperature; and a high-pressure roller mill for ultra-finely crushing the vanadium-titanium magnetite to be ground after the cooling and freezing. The vanadium-titanium magnetite to be ground is sequentially treated with "microwave heating + vacuum water quenching + liquid nitrogen immersion quick freezing + high-pressure roller grinding ultra-fine crushing". After microwave heating, the metal ore inside the ore absorbs heat quickly, increasing the thermal stress difference between metal minerals and non-metallic minerals, which can effectively reduce the difficulty of grinding the ore; then, vacuum water quenching is used to form cracks inside the ore, and water molecules enter the cracks inside the ore under negative pressure, and then the ore is quickly cooled and frozen by liquid nitrogen immersion. After the water in the cracks inside the ore turns into ice, its volume expands to form internal expansion pressure, which further develops the internal cracks, and then high-pressure roller grinding is used to further develop the internal cracks of the ore particles, reducing the ore Bond work index, and at the same time further reducing the particle size of the ore particles, thereby reducing the difficulty of dissociation of various minerals and the energy consumption of grinding during the grinding process, and improving the crushing efficiency.

[0096] The above is a detailed introduction to the method and device for efficient deep grinding of vanadium-titanium magnetite provided by the present application. The various embodiments in the specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same and similar parts between the embodiments can be referenced to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part description. It should be pointed out that for ordinary technicians in this technical field, without departing from the principles of the present application, several improvements and modifications can be made to the present application, and these improvements and modifications also fall within the scope of protection of the claims of the present application.

[0097] It should also be noted that, in this specification, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprise", "include" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the statement "comprises a ..." does not exclude the presence of other identical elements in the process, method, article or device including the element.

Claims

1. A method for high-efficiency deep grinding of vanadium-titanium magnetite, characterized in that: include: The vanadium-titanium magnetite to be ground is heated by using a microwave heating device; Obtaining the temperature difference and the actual water temperature of the vacuum water quenching device, obtaining the 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 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, a vacuum water quenching device is used to perform vacuum water quenching and cooling on the vanadium-titanium magnetite to be ground after the heating treatment; 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 vanadium-titanium magnetite to be ground at room temperature; The vanadium-titanium magnetite to be ground is ultra-finely crushed by a high-pressure roller mill after being cooled and frozen.

2. The method for high-efficiency deep grinding of vanadium-titanium magnetite according to claim 1, characterized in that: After the high pressure roller mill is used to ultra-finely crush the cooled and frozen vanadium-titanium magnetite to be ground, the method further comprises: The ultra-finely crushed vanadium-titanium magnetite to be ground is broken up and sieved by a high-frequency vibrating screen machine to obtain an oversize material with a particle size greater than 2 mm and an undersize material with a particle size less than 2 mm, and the oversize material with a particle size greater than 2 mm is returned to the high-pressure roller mill for cyclic roller crushing; Grinding equipment is used to grind and separate the undersize material with a particle size less than 2mm.

3. The method for high-efficiency deep grinding of vanadium-titanium magnetite according to claim 1, characterized in that: Before the microwave heating device is used to heat the vanadium-titanium magnetite to be ground, the method further comprises: The vanadium-titanium magnetite ore is subjected to coarse crushing, medium crushing and fine crushing in sequence to obtain the vanadium-titanium magnetite to be ground with a particle size of less than 15 mm.

4. The method for high-efficiency deep grinding of vanadium-titanium magnetite according to claim 3, characterized in that: The method of sequentially coarsely crushing, medium-crushing and fine-crushing the vanadium-titanium magnetite ore to obtain the vanadium-titanium magnetite to be ground with a particle size of less than 15 mm comprises: The vanadium-titanium magnetite ore is coarsely crushed by a jaw crusher or a gyratory crusher; The cone crusher is used to perform secondary crushing on the coarsely crushed vanadium-titanium magnetite ore; The vanadium-titanium magnetite ore after medium crushing is screened to obtain undersize with a particle size of less than 15 mm and oversize with a particle size of greater than 15 mm; The sieve material with a particle size greater than 15 mm is crushed by a fine crusher, the crushed vanadium-titanium magnetite ore is screened, the sieve material with a particle size greater than 15 mm is returned to the fine crusher for cyclic fine crushing, and the sieve material with a particle size less than 15 mm is collected as the vanadium-titanium magnetite to be ground.

5. The method for high-efficiency deep grinding of vanadium-titanium magnetite according to claim 1, characterized in that: The method of using a microwave heating device to heat the vanadium-titanium magnetite to be ground comprises: The frequency, power and irradiation time of the microwave heating device are adjusted to heat the vanadium-titanium magnetite to be ground to 300-400°C.

6. The method for high-efficiency deep grinding of vanadium-titanium magnetite according to claim 1, characterized in that: Also includes: 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.

7. A device for high-efficiency deep grinding of vanadium-titanium magnetite, characterized in that: The method for high-efficiency deep grinding of vanadium-titanium magnetite according to any one of claims 1 to 6 comprises: A microwave heating device is used to heat the vanadium-titanium magnetite to be ground; A vacuum water quenching device is used to perform vacuum water quenching and cooling on the vanadium-titanium magnetite to be ground after the heating treatment; Negative pressure circulating liquid nitrogen quick freezing device, used to cool and freeze the vanadium-titanium magnetite to be ground at room temperature; The high pressure roller mill is used to ultra-finely crush the vanadium-titanium magnetite to be ground after being cooled and frozen.

8. The device for high-efficiency deep grinding of vanadium-titanium magnetite according to claim 7, characterized in that: The microwave heating device comprises a microwave generator, a microwave cavity and a microwave local shielding component, wherein the microwave generator is connected to the microwave cavity through a waveguide, the microwave local shielding component is arranged in the microwave cavity, and the microwave local shielding component is used to control the irradiation area of ​​the microwave.

9. The device for high-efficiency deep grinding of vanadium-titanium magnetite according to claim 8, characterized in that: 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.

10. The device for high-efficiency deep grinding of vanadium-titanium magnetite according to claim 7, characterized in that: The negative pressure circulation 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, wherein the liquid nitrogen evaporator is arranged at the bottom of the quick freezing box, the liquid nitrogen supply device is connected to 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 to circulate the air in the quick freezing box, and the vacuum pump is connected to the quick freezing box.

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