Gold ore sample preparation device and method based on liquid nitrogen spraying circulating freezing

Abstract

The invention discloses a device and method for preparing a gold ore sample based on liquid nitrogen spraying circulating freezing, and belongs to the technical field of geological mineral sample preparation. The device for preparing the gold ore sample based on liquid nitrogen spraying circulating freezing comprises a base, and a preparation cylinder and a liquid nitrogen circulating device are fixedly installed on the base; a safety valve is installed on the liquid nitrogen circulating device, a liquid inlet pipe is fixedly installed on one side of the liquid nitrogen circulating device, a circulating pipe and a backflow pipe are fixedly connected between the liquid nitrogen circulating device and the preparation cylinder, a separation assembly is arranged in the preparation cylinder, the circulating pipe penetrates through the separation assembly, and a spraying pipe is installed in the preparation cylinder in a sealed mode through a rotating connector. The spraying pipe is provided with the spraying device, the spraying device is connected with the safety valve, liquid nitrogen is injected into the liquid nitrogen circulating device through the liquid inlet pipe, and after the circulating pump is started, the liquid nitrogen enters the preparation cylinder through the circulating pipe and is sprayed to the surface of the ore in the form of fine fog drops through the spraying pipe, so that the temperature of the ore is reduced to below-160 DEG C within a short time, and the embrittlement effect is achieved.

Description

Technical Field

[0001] This invention relates to the field of geological and mineral sample preparation technology, and in particular to a gold ore sample preparation device and method based on liquid nitrogen spraying and cyclic freezing. Background Technology

[0002] In fields such as geological exploration, mineral resource evaluation, and metallurgical analysis, the pretreatment of gold ore samples is a crucial step in obtaining accurate analytical results. Among these steps, the crushing and grinding of samples is particularly critical, directly affecting the accuracy and reliability of subsequent chemical analysis, spectroscopic detection, and other tasks.

[0003] Traditional methods for preparing ore samples often employ mechanical crushing and grinding techniques at room temperature, such as jaw crushers, ball mills, and rod mills.

[0004] However, due to the characteristics of gold ore such as high hardness, high toughness, and fine particle size, it is easy to agglomerate or locally enrich during grinding at room temperature, resulting in a gold distribution uniformity RSD ≥ 8%, which seriously affects the accuracy of subsequent detection. Summary of the Invention

[0005] The purpose of this invention is to solve the problem that in the prior art, agglomeration or local enrichment easily occurs during room temperature grinding, resulting in gold distribution uniformity RSD≥8%, which seriously affects the accuracy of subsequent detection. Therefore, this invention proposes a gold ore sample preparation device and method based on liquid nitrogen spraying and cyclic freezing.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A gold ore sample preparation device based on liquid nitrogen spraying and circulating freezing includes a base, on which a preparation cylinder and a liquid nitrogen circulation device are fixedly installed. A safety valve is installed on the liquid nitrogen circulation device. An inlet pipe is fixedly installed on one side of the liquid nitrogen circulation device. A circulation pipe and a return pipe are fixedly connected between the liquid nitrogen circulation device and the preparation cylinder. A separator is provided inside the preparation cylinder, and the circulation pipe passes through the separator. A spray pipe is sealed inside the preparation cylinder via a rotary joint, and a spraying device is installed on the spray pipe, which is connected to the safety valve.

[0008] For crushing and grinding mineral materials, preferably, the preparation cylinder includes an outer cylinder and an inner cylinder, with a jacket layer provided between the outer cylinder and the inner cylinder. A gear ring is fixedly installed on the inner cylinder, and a motor is fixedly installed on the base. A reducer and a gear are sequentially installed at the output end of the motor, and the gear meshes with the gear ring.

[0009] To ensure orderly flow of liquid nitrogen and prevent mixing of cryogenic liquid nitrogen with heat-exchanged liquid nitrogen, the separation assembly further includes a first slip ring fixedly installed on the inner wall of the outer cylinder and a circular plate. The circular plate is rotatably installed inside the first slip ring and a sealing gasket is provided between the circular plate and the first slip ring.

[0010] To further assist heat exchange and enhance the cooling effect, the preparation cylinder also includes refrigeration pipes. A second slip ring is fixedly installed on the inner cylinder, and the second slip rings are symmetrically arranged. A third slip ring is fixedly installed on the inner wall of the outer cylinder. The second slip ring and the third slip ring are slidably connected. The refrigeration pipes are equidistantly distributed along the circumference of the second slip rings, wherein the two ends of the refrigeration pipes are located on both sides of the circular plate.

[0011] To drive the liquid nitrogen to circulate within the preparation cylinder, preferably, the liquid nitrogen circulation device includes a housing, in which a baffle plate is fixedly installed, the baffle plate being located on one side of the return pipe, and further includes: an umbrella plate, fixedly installed within the housing and located on both sides of the baffle plate; and an arc-shaped collecting plate, fixedly installed at the bottom of the housing, with the circulation pipe sealed to the bottom end of the arc-shaped collecting plate.

[0012] To collect the evaporated gaseous nitrogen, reduce the internal pressure of the preparation cylinder, prevent overpressure, and use it as a power source for the jetting process to achieve effective recovery and reuse, a gas storage tank is fixedly installed on the housing. A gas collection pipe is fixedly connected between the gas storage tank and the safety valve. A compressor is installed on the gas storage tank. A release pipe is fixedly installed between the gas storage tank and the jetting device. A pressure regulating valve is installed on the release pipe, which is installed inside a rotary joint.

[0013] To further automate the cleaning of the equipment's interior by jet cleaning after grinding or during operation, the jet cleaning device includes a support frame fixedly mounted on the spray pipe, and a jet pipe rotatably mounted within the support frame. It also includes: a connector fixedly mounted within the support frame, one end of which is connected to the release pipe; and a swing head rotatably mounted on the connector, with the jet pipe and the swing head in a sealed connection.

[0014] To further expand the blowing range, the swing head has an airflow channel inside. An impeller is rotatably mounted on the end of the swing head away from the connector. The impeller is located above the airflow channel. A hollow tube is fixedly installed inside the connector. The hollow tube has toothed grooves. A reduction gear unit is drivingly connected between the impeller and the hollow tube.

[0015] To achieve periodic reciprocating oscillation of the swing head and reduce jamming, an adjusting plate is coaxially mounted on the connector head. The adjusting plate has a slot. A stop pin is rotatably mounted in the airflow channel. A deflector plate is rotatably mounted on one end of the stop pin to block the outlet of the airflow channel. The other end of the stop pin is slidably mounted in the slot.

[0016] A method for preparing gold ore samples based on liquid nitrogen spray cyclic freezing includes the following steps:

[0017] Step 1: Add gold ore raw materials crushed to ≤5mm in batches into the preparation device and mix with the grinding rod;

[0018] Step 2: Spray the gold ore raw material in the preparation device with liquid nitrogen. At the same time, heat exchange the preparation device to cool it down, making the ore embrittled.

[0019] Step 3: Rotate the preparation device and grind the brittle ore with the grinding rod for 20-30 minutes;

[0020] Step 4: Collect the vaporized nitrogen after heat exchange and compress it. According to the preset time, transport it to the preparation device for automatic spray cleaning of residual materials inside the equipment.

[0021] Compared with the prior art, the present invention provides a device and method for preparing gold ore samples based on liquid nitrogen spraying and cyclic freezing, which has the following beneficial effects:

[0022] 1. This gold ore sample preparation device based on liquid nitrogen spraying and circulating freezing has liquid nitrogen entering the jacket layer and the cooling pipe through the circulation pipe. Under the drive of the circulation pump, a closed-loop circulation is formed to continuously remove heat and rapidly cool the inside of the inner cylinder to below -160℃. At the same time, the atomizing nozzle on the spray pipe sprays some liquid nitrogen directly onto the surface of the ore to achieve dual freezing enhancement treatment.

[0023] 2. This gold ore sample preparation device based on liquid nitrogen spraying and circulating freezing uses liquid nitrogen to absorb heat from the surrounding environment and evaporate into gaseous nitrogen. The gas is collected by a storage tank and pressurized to the required pressure, so that the high-pressure nitrogen is delivered to the spraying device. This enables automated spraying and cleaning of the inside of the equipment after grinding or during operation, thereby improving the mixing of ore and grinding rods.

[0024] 3. In this gold ore sample preparation device based on liquid nitrogen spraying and circulating freezing, high-pressure nitrogen is delivered to the connector through a release pipe, blown onto the impeller through the airflow channel, and then discharged through the spray pipe. When the impeller rotates, it drives the swing head to move at a constant speed on the connector through the reduction gear set. When the stop pin contacts the edge of the slot, it drives the steering plate to rotate, changing the outlet direction of the airflow, which in turn affects the rotation direction of the impeller, realizing the periodic reciprocating swing of the swing head and increasing the spray angle and range. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the overall structure of a gold ore sample preparation device based on liquid nitrogen spraying and cyclic freezing proposed in this invention.

[0026] Figure 2 This is a schematic diagram of the internal structure of the preparation cylinder of a gold ore sample preparation device based on liquid nitrogen spraying and cyclic freezing proposed in this invention.

[0027] Figure 3 This is a schematic diagram of the liquid nitrogen circulation device of a gold ore sample preparation device based on liquid nitrogen spraying and circulating freezing proposed in this invention.

[0028] Figure 4 This is a schematic diagram of the partition component structure of a gold ore sample preparation device based on liquid nitrogen spraying and cyclic freezing proposed in this invention;

[0029] Figure 5 This is a schematic diagram of the internal structure of the inner cylinder of a gold ore sample preparation device based on liquid nitrogen spraying and cyclic freezing proposed in this invention.

[0030] Figure 6 This is a schematic diagram of the overall structure of the spraying device of a gold ore sample preparation device based on liquid nitrogen spraying and cyclic freezing proposed in this invention;

[0031] Figure 7 This is a schematic diagram of the deceleration gear unit installation structure of a gold ore sample preparation device based on liquid nitrogen spraying and cyclic freezing proposed in this invention.

[0032] Figure 8 This is a schematic diagram of the swing head outlet end structure of a gold ore sample preparation device based on liquid nitrogen spraying and circulating freezing proposed in this invention.

[0033] Figure 9 This is a schematic diagram of the stop pin structure of a gold ore sample preparation device based on liquid nitrogen spraying and cyclic freezing proposed in this invention;

[0034] Figure 10 This is a schematic diagram of the regulating plate structure of a gold ore sample preparation device based on liquid nitrogen spraying and cyclic freezing proposed in this invention.

[0035] In the diagram: 1. Base; 2. Preparation cylinder; 201. Outer cylinder; 202. Inner cylinder; 203. Jacket layer; 204. Gear ring; 205. Second slip ring; 206. Third slip ring; 3. Liquid nitrogen circulation device; 301. Box body; 302. Baffle plate; 303. Umbrella plate; 304. Arc-shaped collection plate; 305. Gas storage tank; 306. Gas collection pipe; 307. Compressor; 308. Release pipe; 4. Safety valve; 5. Liquid inlet pipe; 6. Circulation pipe; 7. Return pipe; 8. Separating assembly; 801. 802. Slip ring; 803. Circular plate; 804. Sealing gasket; 9. Spray pipe; 10. Pulsating device; 1005. Support frame; 1006. Pulsating pipe; 1007. Connector; 1008. Swing head; 1009. Airflow channel; 10000. Impeller; 1001. Hollow tube; 1002. Gear groove; 1001. Reduction gear unit; 1010. Adjusting plate; 1011. Groove; 1012. Stop pin; 1013. Steering plate; 11. Motor; 12. Gear; 13. Refrigeration pipe. Detailed Implementation

[0036] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0037] In the description of this invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0038] Example:

[0039] Reference Figures 1-10A gold ore sample preparation device based on liquid nitrogen spraying and circulating freezing includes a base 1, on which a preparation cylinder 2 and a liquid nitrogen circulation device 3 are fixedly installed. A safety valve 4 is installed on the liquid nitrogen circulation device 3 to monitor and release overpressure gas within the system, ensuring the safe operation of the entire device. An inlet pipe 5 is fixedly installed on one side of the liquid nitrogen circulation device 3 for connecting to an external liquid nitrogen source. A circulation pipe 6 and a return pipe 7 are fixedly connected between the liquid nitrogen circulation device 3 and the preparation cylinder 2, forming a complete liquid nitrogen circulation path. A circulation valve is fixedly installed on the circulation pipe 6. The pump and the preparation cylinder 2 are equipped with a partition component 8. The circulation pipe 6 passes through the partition component 8, allowing liquid nitrogen to enter different areas of the preparation cylinder 2 for cooling. Furthermore, a spray pipe 9 is sealed and installed inside the preparation cylinder 2 through a rotary joint. One end of the spray pipe 9 is the liquid inlet, and the other end is closed. The spray pipe 9 has a DN15 pipe diameter and eight atomizing nozzles are evenly distributed to ensure that the liquid nitrogen evenly covers the surface of the ore. A blowing device 10 is installed on the spray pipe 9. The blowing device 10 is connected to the safety valve 4 and can release the recovered nitrogen gas to realize the automatic cleaning function.

[0040] The present invention provides a gold ore sample preparation device based on liquid nitrogen spraying and circulating freezing. Liquid nitrogen is injected into the liquid nitrogen circulation device 3 through the liquid inlet pipe 5. After the circulation pump is started, the liquid nitrogen enters the preparation cylinder 2 through the circulation pipe 6 and is sprayed onto the ore surface in the form of fine droplets through the spray pipe 9, so that the temperature drops to below -160°C in a short time, achieving the embrittlement effect.

[0041] To reduce the evaporation of cold air from the opening of the preparation cylinder 2 and ensure effective control of the internal pressure, a sealing door is installed at the opening of the preparation cylinder 2. The sealing door not only serves as a physical isolation but also effectively prevents the escape of low-temperature gas, thereby maintaining the low-temperature environment inside the preparation cylinder 2. A high-performance sealing ring is provided at the edge of the sealing door to ensure a tight fit with the opening of the preparation cylinder 2 and prevent cold air leakage. Since the atomizing nozzle on the spray pipe 9 sprays liquid nitrogen in the form of fine droplets onto the surface of the ore, the liquid nitrogen absorbs heat from the ore and the surrounding air and evaporates rapidly into nitrogen gas. Therefore, an exhaust valve is installed on the sealing door to regulate the pressure inside the preparation cylinder 2. When the gas pressure inside the preparation cylinder 2 exceeds the set value, the exhaust valve can automatically open to release excess gas and avoid the risk of overpressure. Furthermore, the exhaust valve is connected to the safety valve 4 on the liquid nitrogen circulation device 3 to form a complete pressure management system. Specifically, the collection pipe leading out from the safety valve 4 extends to the position of the exhaust valve on the sealing door, so that the nitrogen gas released by the exhaust valve can be recycled through this pipe.

[0042] Preparation cylinder 2 is the core component of the entire cryogenic freezing and grinding process, as shown in the reference. Figure 2The preparation cylinder 2 includes an outer cylinder 201 and an inner cylinder 202. A jacket layer 203 is provided between the outer cylinder 201 and the inner cylinder 202. Thermally conductive silicone grease is filled in the jacket layer 203 for heat exchange with liquid nitrogen. A gear ring 204 is fixedly installed on the inner cylinder 202. A motor 11 is fixedly installed on the base 1. A reducer and a gear 12 are installed in sequence at the output end of the motor 11. The gear 12 meshes with the gear ring 204, thereby driving the inner cylinder 202 to rotate around its axis to crush and grind the mineral materials.

[0043] Furthermore, referring to Figure 2 and Figure 4 and Figure 5 A partition component 8 is provided inside the preparation cylinder 2 to manage the space between the inner cylinder 202 and the jacket layer 203, ensuring orderly flow of liquid nitrogen and improving heat exchange efficiency. Specifically, the partition component 8 includes a first slip ring 801 fixedly installed on the inner wall of the outer cylinder 201 and a circular plate 802. The circular plate 802 is rotatably installed inside the first slip ring 801, and a sealing gasket 803 is provided between the circular plate 802 and the first slip ring 801 to prevent liquid nitrogen leakage. At the same time, the circular plate 802 is allowed to rotate with the inner cylinder 202 without affecting the sealing performance. In addition, the preparation cylinder 2 also includes a refrigeration pipe 13 as an auxiliary heat exchange structure to enhance the cooling effect. A second slip ring 13 is fixedly installed on the inner cylinder 202. The second slip ring 205 and the third slip ring 206 are symmetrically arranged. The third slip ring 206 is fixedly installed on the inner wall of the outer cylinder 201. The second slip ring 205 and the third slip ring 206 are slidably connected. The refrigeration pipes 13 are evenly distributed along the circumference of the second slip ring 205, so that the refrigeration pipes 13 can maintain a stable operating state during the rotation of the inner cylinder 202, avoiding damage or leakage of the pipes due to movement. In particular, the two ends of the refrigeration pipes 13 are located on both sides of the circular plate 802, which realizes the separation of liquid nitrogen inlet and outlet, avoids confusion, and makes the liquid nitrogen after heat exchange concentrated between the circular plate 802 and the inner side wall of the outer cylinder 201, and uniformly recycled to the liquid nitrogen circulation device 3 through the return pipe 7.

[0044] In actual operation, liquid nitrogen enters the jacket layer 203 and the cooling pipe 13 through the circulation pipe 6, forming a closed loop under the drive of the circulation pump, continuously removing heat and rapidly cooling the inside of the inner cylinder 202 to below -160℃. At the same time, the atomizing nozzle on the spray pipe 9 sprays some liquid nitrogen directly onto the surface of the ore, achieving dual freezing enhancement treatment.

[0045] During liquid nitrogen circulation, after heat exchange with the thermally conductive silicone grease inside the jacket layer 203, the liquid nitrogen absorbs heat from the surrounding environment and evaporates into gaseous nitrogen. The nitrogen gas initially accumulates within the closed system, causing an increase in internal pressure. To prevent overpressure, refer to... Figure 3The liquid nitrogen circulation device 3 includes a box 301, which is a closed container structure. A baffle plate 302 is fixedly installed inside the box 301. The baffle plate 302 is located on one side of the return pipe 7. When the liquid nitrogen returns to the box 301 after heat exchange, it will first collide with the baffle plate 302 to form a preliminary gas-liquid separation. It also includes an umbrella plate 303 and an arc-shaped collection plate 304.

[0046] The umbrella plate 303 is fixedly installed inside the housing 301 and located on both sides of the baffle plate 302. It serves to guide the flow and prevent splashing, thus avoiding splashing or local accumulation of liquid nitrogen during the flow process and further optimizing the distribution of liquid nitrogen.

[0047] The arc-shaped collecting plate 304 is fixedly installed at the bottom of the box 301. It has a semi-circular arc structure and can effectively collect the liquid nitrogen at the bottom of the box 301, so that it flows to the circulation pipe 6. The circulation pipe 6 is sealed to the bottom end of the arc-shaped collecting plate 304, ensuring that the liquid nitrogen can smoothly enter the circulation passage and be transported to the jacket layer 203 of the preparation cylinder 2 for cooling.

[0048] To effectively recover and reuse the overpressure released gas in the preparation cylinder 2, a gas storage tank 305 is fixedly installed on the housing 301. A gas collection pipe 306 is fixedly connected between the gas storage tank 305 and the safety valve 4. A compressor 307 is installed on the gas storage tank 305 to pressurize the low-pressure nitrogen to the required pressure for subsequent spray cleaning. A release pipe 308 is fixedly installed between the gas storage tank 305 and the spray device 10. A pressure regulating valve is installed on the release pipe 308 to adjust the output pressure according to the actual spraying requirements and achieve precise control. In particular, the release pipe 308 is installed inside the rotary joint, so that the high-pressure nitrogen can be stably delivered to the spray device 10 without interfering with the rotation of the spray pipe 9, thereby realizing automated spray cleaning of the equipment interior after grinding or during operation.

[0049] With the above-described structure, liquid nitrogen is injected into the housing 301 through the inlet pipe. The liquid nitrogen then enters the cavity between the inner cylinder 202 and the circular plate 802 through the circulation pipe 6. Part of the liquid nitrogen enters the inner cylinder 202 through the spray pipe 9 to embrittle the ore, while the other part enters through the inlet end of the cooling pipe 13, where it exchanges heat with the thermally conductive silicone grease in the jacket layer 203. The liquid nitrogen then exits from the outlet end of the cooling pipe 13 into the cavity between the circular plate 802 and the inner sidewall of the outer cylinder 201, and returns to the housing 301 through the return pipe 7. After heat exchange, the liquid nitrogen is guided by the baffle plate 302 and umbrella plate 303, and then flows into the arc-shaped collection plate 304. It is then sent back into the jacket layer 203 for cooling through the circulation pipe 6. The gas passes through the safety valve 4 and is introduced into the gas storage tank 305 through the gas collection pipe 306. The compressor 307 pressurizes the low-pressure nitrogen and stores it in the gas storage tank 305. According to the preset time, the solenoid valve is activated, so that the high-pressure nitrogen is delivered to the spraying device 10 through the release pipe 308 to spray and clean the inside of the equipment, realizing the dual utilization of liquid nitrogen and gaseous nitrogen.

[0050] Reference Figures 6-10 The blowing device 10 is an important component of the gold ore sample preparation device based on liquid nitrogen spraying and circulating freezing. It is used to realize the automatic blowing and cleaning function inside the equipment. Referring to the figure, the blowing device 10 includes a support frame 1001 fixedly installed on the spray pipe 9, and a blowing pipe 1002 rotatably installed in the support frame 1001. One end of the blowing pipe 1002 is rotatably installed inside the support frame 1001 through a bearing, allowing it to swing freely within a certain angle range, thereby covering a larger blowing range. It also includes a connector 1003 and a swing head 1004.

[0051] The connector 1003 is fixedly installed inside the support frame 1001, with one end connected to the release pipe 308, serving as a transition and connection; the swing head 1004 is rotatably installed on the connector 1003, and the blow pipe 1002 is sealed to the swing head 1004, allowing the blow pipe 1002 to swing flexibly in different directions. The swing head 1004 and the blow pipe 1002 are sealed to ensure that high-pressure gas can smoothly enter the blow pipe 1002 without leakage and be ejected from the nozzle.

[0052] Furthermore, an airflow channel 1005 is provided inside the swing head 1004. An impeller 1006 is rotatably mounted at the end of the swing head 1004 away from the connector 1003. The impeller 1006 is located above the airflow channel 1005. In particular, the swing head 1004 below the impeller 1006 has two outlets to guide liquid nitrogen to be discharged from different outlets. A hollow tube 1007 is fixedly installed inside the connector 1003. The hollow tube 1007 has a toothed groove 1008. A reduction gear unit 1009 is connected between the impeller 1006 and the hollow tube 1007. When the impeller 1006 rotates, the reduction gear unit 1009 drives the entire swing head 1004 to rotate on the hollow tube 1007, thereby realizing the swing of the spray pipe 1002.

[0053] An adjusting plate 1010 is coaxially mounted on the connector 1003. The adjusting plate 1010 is provided with a slot 1011. A stop pin 1012 is rotatably installed in the airflow channel 1005. A deflector plate 1013 is rotatably installed on one end of the stop pin 1012 to block the outlet of the airflow channel 1005. The other end of the stop pin 1012 is slidably installed in the slot 1011. By controlling the displacement of the stop pin 1012, the deflector plate 1013 can be controlled to alternately block the two outlets of the airflow channel 1005, thereby affecting the rotation direction of the impeller 1006 and realizing the periodic reciprocating oscillation of the swing head 1004.

[0054] A method for preparing gold ore samples based on liquid nitrogen spray cyclic freezing includes the following steps:

[0055] Step 1: Select gold ore raw materials crushed to ≤5mm, and add the selected gold ore raw materials into the inner cylinder 202 of the preparation cylinder 2 in batches. The processing amount of each batch is 50kg. Ensure that the sealing door is closed and locked to reduce the evaporation of cold air.

[0056] Step 2: Start the liquid nitrogen circulation device 3 and inject liquid nitrogen into the box 301 through the liquid inlet pipe 5. The liquid nitrogen enters the cavity between the inner cylinder 202 and the circular plate 802 through the circulation pipe 6. Part of the liquid nitrogen enters the inner cylinder 202 through the spray pipe 9 to embrittle the ore, and the other part of the liquid nitrogen enters through the inlet end of the cooling pipe 13 and exchanges heat with the thermally conductive silicone grease in the jacket layer 203.

[0057] Step 3: Start the motor 11, which drives the inner cylinder 202 to rotate through the reducer, gear 12 and gear ring 204. During the rotation of the inner cylinder 202, the rod medium impacts and rubs the embrittled ore to grind it. The grinding time is 20 to 30 minutes.

[0058] Step 4: Collect the nitrogen gas after heat exchange, compress it and store it in the high-pressure gas storage tank 305. According to the preset time, the high-pressure nitrogen gas is delivered to the connector 1003 through the release pipe 308, blown towards the impeller 1006 through the airflow channel 1005, and then discharged through the spray pipe 1002. When the impeller 1006 rotates, it drives the swing head 1004 to move at a constant speed on the connector 1003 through the reduction gear unit 1009. When the stop pin 1012 contacts the edge of the slot 1011, it drives the deflector plate 1013 to rotate, changing the outlet direction of the airflow, thereby affecting the rotation direction of the impeller 1006, realizing the periodic reciprocating swing of the swing head 1004.

[0059] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A gold ore sample preparation device based on liquid nitrogen spraying and cyclic freezing, comprising a base (1), characterized in that, A preparation cylinder (2) and a liquid nitrogen circulation device (3) are fixedly installed on the base (1). A safety valve (4) is installed on the liquid nitrogen circulation device (3). An inlet pipe (5) is fixedly installed on one side of the liquid nitrogen circulation device (3). A circulation pipe (6) and a return pipe (7) are fixedly connected between the liquid nitrogen circulation device (3) and the preparation cylinder (2). A separation component (8) is provided inside the preparation cylinder (2). The circulation pipe (6) passes through the separation component (8). A spray pipe (9) is sealed inside the preparation cylinder (2) through a rotary joint. A spraying device (10) is installed on the spray pipe (9). The spraying device (10) is connected to the safety valve (4).

2. The gold ore sample preparation device based on liquid nitrogen spraying and cyclic freezing according to claim 1, characterized in that, The preparation cylinder (2) includes an outer cylinder (201) and an inner cylinder (202). A jacket layer (203) is provided between the outer cylinder (201) and the inner cylinder (202). A gear ring (204) is fixedly installed on the inner cylinder (202). A motor (11) is fixedly installed on the base (1). A reducer and a gear (12) are sequentially installed at the output end of the motor (11). The gear (12) meshes with the gear ring (204).

3. The gold ore sample preparation device based on liquid nitrogen spraying and cyclic freezing according to claim 2, characterized in that, The partition assembly (8) includes a first slip ring (801) fixedly installed on the inner wall of the outer cylinder (201), and A circular plate (802) is rotatably mounted inside the first slip ring (801), and a sealing gasket (803) is provided between the circular plate (802) and the first slip ring (801).

4. The gold ore sample preparation device based on liquid nitrogen spraying and cyclic freezing according to claim 3, characterized in that, The preparation cylinder (2) further includes a refrigeration pipe (13). A second slip ring (205) is fixedly installed on the inner cylinder (202). The second slip rings (205) are symmetrically arranged. A third slip ring (206) is fixedly installed on the inner wall of the outer cylinder (201). The second slip ring (205) and the third slip ring (206) are slidably connected. The refrigeration pipes (13) are equidistantly distributed along the circumference of the second slip rings (205). The two ends of the refrigeration tube (13) are located on both sides of the circular plate (802).

5. The gold ore sample preparation device based on liquid nitrogen spraying and cyclic freezing according to claim 1, characterized in that, The liquid nitrogen circulation device (3) includes a housing (301), a baffle plate (302) is fixedly installed inside the housing (301), the baffle plate (302) is located on one side of the return pipe (7), and further includes: The umbrella panel (303) is fixedly installed inside the housing (301) and located on both sides of the baffle plate (302); An arc-shaped collecting plate (304) is fixedly installed at the bottom of the box (301), and the circulation pipe (6) is sealed to the bottom end of the arc-shaped collecting plate (304).

6. The gold ore sample preparation device based on liquid nitrogen spraying and cyclic freezing according to claim 5, characterized in that, An air tank (305) is fixedly installed on the housing (301). An air collecting pipe (306) is fixedly connected between the air tank (305) and the safety valve (4). A compressor (307) is installed on the air tank (305). A release pipe (308) is fixedly installed between the air tank (305) and the blowing device (10). A pressure regulating valve is installed on the release pipe (308). The release tube (308) is installed inside the rotary joint.

7. The gold ore sample preparation device based on liquid nitrogen spraying and cyclic freezing according to claim 6, characterized in that, The spraying device (10) includes a support frame (1001) fixedly mounted on the spray pipe (9), and a spray pipe (1002) rotatably mounted within the support frame (1001), and further includes: The connector (1003) is fixedly installed inside the support frame (1001), and one end is connected to the release tube (308); A swing head (1004) is rotatably mounted on the connector (1003), and the blow pipe (1002) is sealed to the swing head (1004).

8. The gold ore sample preparation device based on liquid nitrogen spraying and cyclic freezing according to claim 7, characterized in that, An airflow channel (1005) is provided inside the swing head (1004). An impeller (1006) is rotatably mounted on the end of the swing head (1004) away from the connector (1003). The impeller (1006) is located above the airflow channel (1005). A hollow tube (1007) is fixedly installed inside the connector (1003). The hollow tube (1007) has a toothed groove (1008). A reduction gear unit (1009) is connected between the impeller (1006) and the hollow tube (1007).

9. The gold ore sample preparation device based on liquid nitrogen spraying and cyclic freezing according to claim 8, characterized in that, An adjusting plate (1010) is coaxially mounted on the connector (1003). The adjusting plate (1010) is provided with a slot (1011). A stop pin (1012) is rotatably installed in the airflow channel (1005). A steering plate (1013) is rotatably installed on one end of the stop pin (1012) for blocking the outlet of the airflow channel (1005). The other end of the stop pin (1012) is slidably installed in the slot (1011).

10. A method for preparing gold ore samples based on liquid nitrogen spray-circulating freezing, comprising using the gold ore sample preparation apparatus based on liquid nitrogen spray-circulating freezing as described in any one of claims 1-9, characterized in that, Includes the following steps: Step 1: Add gold ore raw materials crushed to ≤5mm into the preparation device in batches and mix with the grinding rod; Step 2: Spray the gold ore raw material in the preparation device with liquid nitrogen. At the same time, heat exchange the preparation device to cool it down, so as to make the ore embrittled. Step 3: Rotate the preparation device and grind the embrittled ore with the grinding rod for 20-30 minutes; Step 4: Collect the vaporized nitrogen after heat exchange and compress it. According to the preset time, transport it to the preparation device for automatic spray cleaning of residual materials inside the equipment.

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