A screening device and method for testing the zircon grade of marine sandy sediments

Abstract

The present application relates to the technical field of sediment screening, and discloses a screening device and method for testing the zircon grade of marine sandy sediment, which comprises a bottom plate, a two-stage screening mechanism being arranged on the bottom plate, and the two-stage screening mechanism is composed of a spiral flow guide groove, a reverse spiral flow guide blade and a conical centrifugal screen mesh, the three are coaxially arranged, the force field is smoothly transitioned from cyclone to centrifugal, the back mixing phenomenon caused by material transfer between traditional devices is eliminated, and the separation precision and the recovery rate of target components are improved. Different densities of first heavy liquid are injected into each ring layer of the spiral flow guide groove through the first liquid injection mechanism, an axial density gradient field is formed, and different density mineral particles are separated step by step in the movement process along the spiral flow guide groove due to the synergistic effect of centrifugal force and the density gradient. The density gradient can be flexibly adjusted according to the characteristics of the sample, and the separation precision and adaptability are significantly better than those of the traditional method of single density heavy liquid.

Description

Technical Field

[0001] This invention belongs to the field of sediment screening technology, specifically a screening device and method for testing zircon grade in marine sandy sediments. Background Technology

[0002] Currently, the screening of zircon in marine sediments mainly employs the traditional heavy liquid separation method. The basic process involves: first, wet sieving to remove muddy components; then, drying the sample and passing it sequentially through heavy liquids of different densities for separation; finally, manually picking zircon particles under a microscope. This traditional process has the following prominent problems: First, the process is cumbersome and time-consuming. In traditional methods, wet screening and heavy liquid separation are carried out independently in separate steps. Samples need to be transferred repeatedly between different devices, making the operation complex. The processing cycle for a single sample usually takes several days, which is difficult to meet the needs of rapid testing of large batches of samples.

[0003] Second, the separation accuracy is low and the reproducibility is poor. Traditional heavy liquid separation often uses heavy liquid of a single density, which cannot form a continuous density gradient, making it difficult to achieve accurate separation of mineral particles of different densities. At the same time, in the process from hydrocyclone separation to centrifugal separation, the material needs to be transferred between different devices, which can easily cause backmixing, resulting in the loss of target components and low zircon recovery rate.

[0004] Third, traditional methods often use toxic organic heavy liquids, which pose potential hazards to the health of operators and the environment.

[0005] In summary, existing technologies suffer from drawbacks such as cumbersome procedures, low separation accuracy, low recovery rate, and poor safety and environmental performance. There is an urgent need for an integrated, efficient, high-precision, and environmentally friendly zircon screening device and method. Summary of the Invention

[0006] In view of the above situation and to overcome the defects of the prior art, the present invention provides a screening device and method for testing the zircon grade of marine sandy sediments, which effectively solves the problems mentioned in the background art.

[0007] To achieve the above objectives, the present invention provides the following technical solution: a screening device for testing the zircon grade of marine sandy sediments, comprising a base plate, a secondary screening mechanism on the base plate, and a primary screening mechanism above the secondary screening mechanism; The secondary screening mechanism consists of a first separation component, a second separation component, and a third separation component; The first separation component includes a mounting frame mounted on a base plate, a secondary screening cylinder mounted on the mounting frame, a spiral guide channel installed inside the secondary screening cylinder, a plurality of first heavy liquid injection holes on the side wall of the spiral guide channel, a fixed tube end connected to the first heavy liquid injection hole, the fixed tube end corresponding to each turn of the spiral guide channel communicating with the inside of the first heavy liquid tube, the inlet of the first heavy liquid tube being connected to the first injection mechanism, a drain channel at the lowest point of each turn of the spiral guide channel except the bottom turn, a drain filter screen installed inside the drain channel, a waste liquid collection mechanism connected to the bottom of the drain channel, a material injection mechanism connected to the inlet of the spiral guide channel, and an annular distribution frame connected to the bottom of the outlet of the spiral guide channel, and the annular distribution frame being installed inside the secondary screening cylinder; The second separation component includes a secondary screening shaft that is rotatably connected to the top of the secondary screening cylinder. The secondary screening shaft is powered by a secondary screening motor installed on the secondary screening cylinder. A fixed cylinder is installed at the lower part of the annular distribution frame and connected to the bottom of the secondary screening cylinder. Reverse spiral guide vanes are fixedly installed on the outer surface of the secondary screening shaft. An annular heavy liquid distributor is installed inside the fixed cylinder. A second heavy liquid nozzle that communicates with the inside of the annular heavy liquid distributor is uniformly machined on the annular heavy liquid distributor. A second liquid injection mechanism is connected to the annular heavy liquid distributor. A gradient density sorting ring is installed inside the fixed cylinder below the annular heavy liquid distributor and is rotatably connected to the secondary screening shaft. The third separation component includes conical centrifugal screens arranged in an array from top to bottom. The conical centrifugal screens are connected by several connecting vertical rods. The conical centrifugal screens are rotatably installed in a fixed cylinder. One end of a connecting horizontal rod is connected to the upper conical centrifugal screen, and the other end of the connecting horizontal rod is connected to the lower end of the secondary screening shaft.

[0008] Preferably, the width of the spiral guide channel decreases linearly from the initial end to the end, and the depth of the channel increases linearly from the initial end to the end. The second heavy liquid nozzles on the same vertical plane are a group, and there are multiple groups, with different spray angles for the second heavy liquid nozzles in each group; The basin-shaped collection box has several rings of sorting holes along the radial direction, and the radius of the sorting holes increases from the inside to the outside. The aperture of each conical centrifugal screen is different and decreases from top to bottom. The outer surface of the conical centrifugal screen is coated with a zircon hydrophobic modified coating.

[0009] Preferably, the primary screening mechanism includes a primary screening cylinder mounted on the top of the mounting frame, a primary screening motor mounted on the top of the primary screening cylinder, a driving bevel gear fixedly connected to the end of the output shaft of the primary screening motor, the driving bevel gear meshing with driven bevel gear one and driven bevel gear two, driven bevel gear two fixedly mounted on the upper end of the hollow shaft, several connecting rods fixedly connected to the lower end of the hollow shaft, a primary screening screen mounted on the end of the connecting rods, the primary screening screen rotatably mounted inside the primary screening cylinder, the hollow shaft rotatably mounted through the top of the primary screening cylinder, driven bevel gear one fixedly mounted on the upper end of the flexible corrugated plate rotating shaft, the flexible corrugated plate rotating shaft rotatably mounted through the hollow shaft, several flexible corrugated plates fixedly mounted on the outer surface of the flexible corrugated plate rotating shaft, and several flexible plates mounted on the inner side of the primary screening screen; The primary screening cylinder is equipped with a feed inlet at the top; The primary screening mechanism also includes a water supply component, which includes a water storage tank mounted on the base plate, a water supply pump mounted on the water storage tank, and the inlet of the water supply pump is connected to the inside of the water storage tank. The outlet of the water supply pump is connected to one end of a water supply pipe, and the other end of the water supply pipe is connected to the inside of the primary screening cylinder. The primary screening mechanism also includes a wastewater recovery component, which includes a wastewater recovery pipe connected to the lower part of the primary screening cylinder. The end of the wastewater recovery pipe is connected to a wastewater collection tank, which is installed on the base plate. A wastewater recovery control valve is connected in series on the wastewater recovery pipe.

[0010] Preferably, the feeding mechanism includes a feeding pipe installed on the secondary screening cylinder. The inlet of the feeding pipe is connected to the outlet of the peristaltic pump. The inlet of the peristaltic pump is connected to one end of a conveying pipe. The other end of the conveying pipe is connected to a support pipe. The support pipe is installed on the primary screening cylinder and is rotatably connected to the lower part of the primary screening screen. A feeding control valve is connected in series on the support pipe. The outlet of the feeding pipe extends to the inlet of the spiral guide channel and is tangentially arranged along the inlet of the spiral guide channel.

[0011] Preferably, the first injection mechanism includes a first heavy liquid storage tank mounted on a base plate. The first heavy liquid storage tank has a plurality of first heavy liquid storage chambers, each of which stores a first heavy liquid of a different density. A first heavy liquid injection pump is installed on the end wall of the first heavy liquid storage chamber, and the inlet of the first heavy liquid injection pump is connected to the inside of the first heavy liquid storage chamber. The outlet of the first heavy liquid injection pump is connected to one end of a first heavy liquid delivery pipe, and the other end of the first heavy liquid delivery pipe is connected to a first heavy liquid pipe.

[0012] Preferably, the second injection mechanism includes a second heavy liquid storage tank mounted on a base plate, the second heavy liquid storage tank storing a second heavy liquid, a second heavy liquid supply pump mounted on the second heavy liquid storage tank, the inlet of the second heavy liquid supply pump communicating with the inside of the second heavy liquid storage tank, the outlet of the second heavy liquid supply pump being connected to one end of a second heavy liquid delivery pipe, and the other end of the second heavy liquid delivery pipe communicating with the inside of an annular heavy liquid distributor.

[0013] Preferably, the waste liquid collection mechanism includes one end of a first waste heavy liquid recovery pipe connected to the lower part of the drainage channel, the other end of the first waste heavy liquid recovery pipe connected to a waste liquid recovery tank, a waste liquid collection vacuum pump installed on the waste liquid recovery tank, one end of a second waste liquid recovery pipe connected to the waste liquid recovery tank, the other end of the second waste liquid recovery pipe connected to the lower part of the secondary screening cylinder and communicating with the inside of the fixed cylinder.

[0014] Preferably, a waste collection mechanism is connected to the secondary screening cylinder, and the waste collection mechanism includes a first waste collection component and a second waste collection component; The first waste collection assembly includes one end of a first waste recovery pipe installed on the secondary screening cylinder, with the inlet extending to the position of the first heavy liquid injection hole near the uppermost side. The other end of the first waste recovery pipe is connected to the primary waste collection tank, which is installed on the base plate and equipped with a waste collection vacuum pump. The second waste collection assembly includes a basin-shaped collection box connected to the lower part of the gradient density sorting ring, a second waste recycling pipe connected to one end of the bottom of the basin-shaped collection box, and the other end of the second waste recycling pipe connected to the inside of the second waste recycling tank, which is mounted on a mounting frame.

[0015] Preferably, a collection mechanism is connected to the lower part of the conical centrifugal screen. The collection mechanism includes an output pipe rotatably connected to the lower part of the conical centrifugal screen. The length and diameter of the output pipes connected to the conical centrifugal screen decrease sequentially from top to bottom. The output pipes are concentrically arranged and pass through the bottom of the secondary screening cylinder. Except for the output pipe connected to the uppermost conical centrifugal screen, the lower part of the remaining output pipes is connected to a discharge guide frame. The outlet position of each discharge guide frame is different. Zircon collection boxes are provided below the outlet of the discharge guide frame and the outlet of the output pipe. The outermost one is installed on the secondary screening cylinder, and the inner output pipe is connected to the discharge guide frame.

[0016] This invention provides a screening method for testing the zircon grade of marine sandy sediments, based on the aforementioned screening device for testing the zircon grade of marine sandy sediments, comprising the following steps: Step 1: The sediment sample taken from the seabed is injected into the primary screening cylinder through the feed inlet. The water supply pump is started to send the cleaning water in the storage tank into the primary screening cylinder through the water supply pipe. At the same time, the primary screening motor is started, which drives the active bevel gear to rotate, and drives the hollow shaft and the flexible corrugated plate shaft to rotate in opposite directions. This causes the primary screening screen to rotate, and the flexible plate and the flexible corrugated plate to rotate in opposite directions, which improves the efficiency of stirring and separation. This separates the mud and fine sand components from the debris samples within the target particle size range. The mud and fine sand components pass through the primary screening screen and enter the primary screening cylinder. After cleaning, the wastewater in the primary screening cylinder is discharged, and the debris samples within the target particle size range remain on the primary screening screen. Step 2: Open the injection control valve and stop the primary screening motor. The debris sample within the target particle size range falls on the primary screening screen, passes through the injection control valve and enters the support tube, then enters the conveying pipe. Start the peristaltic pump to peristalse and transport the debris sample into the injection pipe, and then into the spiral guide groove. Step 3: The debris sample enters the spiral guide channel. The first heavy liquid is injected into the spiral guide channel through the first liquid injection mechanism, so that the heavy liquid density of each layer of the spiral guide channel is different, forming an axial density gradient field. When the debris sample moves in the spiral guide channel, under the action of centrifugal force and axial density gradient field, the density of the debris sample is less than that of the heavy liquid and floats to the position of the first waste recovery pipe, while the density of the debris sample is greater than that of the heavy liquid and moves downward along the spiral guide channel, flows out through the lower side of the spiral guide channel, and enters the fixed cylinder through the annular distribution frame. The secondary screening motor is started, driving the secondary screening shaft to rotate, which in turn drives the reverse spiral guide vanes to rotate. At the same time, the second heavy liquid is introduced into the annular heavy liquid distributor through the second liquid injection mechanism. The heavy liquid is sprayed upward at a certain angle through the second heavy liquid nozzle. The reverse spiral guide vanes rotate, driving the heavy mineral combination to mix thoroughly with the heavy liquid, forming a uniform suspension. Under the action of centrifugal force, mineral particles of different densities move towards the wall of the secondary screening cylinder. Due to the difference in particle size and density, their movement speed and trajectory are also different. Medium and heavy minerals with lower density move slower and fall into the inner and middle sorting holes of the basin-shaped collection box for discharge. Heavy minerals with higher density move faster and fall into the outer sorting holes of the basin-shaped collection box for discharge, and then fall into the conical centrifugal screen. Increasing the speed of the secondary screening motor drives the conical centrifugal screen to rotate. Under centrifugal force, zircon particles are thrown outward and sequentially pass through different conical centrifugal screens for grading and interception. The heavy liquid is thrown onto the wall of the secondary screening cylinder and falls to the bottom wall of the secondary screening cylinder. The zircon-loving hydrophobic modified coating on the surface of the conical centrifugal screen enables rapid separation of the heavy liquid. The remaining small amount of medium and heavy minerals, due to their low affinity with the coating, are thrown into the heavy liquid by centrifugal force. After separation, the speed of the secondary screening motor is reduced, causing the zircon to slide down the inner side of the conical centrifugal screen and be discharged through the collection mechanism.

[0017] Step 4: The debris sample enters the spiral guide channel, and the first heavy liquid injection pump is started to extract the first heavy liquid of different densities in the first heavy liquid storage chamber. The liquid enters the first heavy liquid pipe through the first heavy liquid delivery pipe, enters the first heavy liquid injection hole through the fixed pipe, and enters the spiral guide channel through the first heavy liquid injection hole, so that the heavy liquid density of each turn of the spiral guide channel is different, forming an axial density gradient field. Step 5: Start the second heavy liquid supply pump to extract the second heavy liquid from the second heavy liquid storage tank, so that the second heavy liquid enters the annular heavy liquid distributor through the second heavy liquid delivery pipe and is sprayed out through the second heavy liquid nozzle; Step Six: Start the waste collection vacuum pump to create a vacuum in the primary waste collection tank, so that the impurity sample that floats to the position of the first waste recovery pipe is sucked into the primary waste collection tank through the first waste recovery pipe. The ore collected in the basin-shaped collection box is then collected in the second waste collection tank through the second waste collection pipe. Step 7: Start the waste liquid collection vacuum pump to evacuate the waste liquid recovery tank, so that the heavy liquid and corresponding ore on the bottom wall of the fixed cylinder are sucked into the waste liquid recovery tank through the second waste liquid recovery pipe, and the heavy liquid in the spiral guide channel is sucked into the waste liquid recovery tank through the first waste heavy liquid recovery pipe. Step 8: The zircons collected on the upper connecting crossbar are discharged into the zircon collection box through the central output pipe. The remaining zircons on the connecting crossbar enter the discharge guide frame through the corresponding output pipe, and then enter the corresponding zircon collection box for collection.

[0018] Compared with existing technologies, the advantages of this invention are as follows: By integrating the primary and secondary screening mechanisms into one unit, the invention achieves continuous operation of wet screening and heavy liquid separation, eliminating the need for sample transfer between different devices and simplifying the operation process. Simultaneously, through the coordinated control of various components by the control system, the entire process from water supply and cleaning, screening and stirring, material transfer, heavy liquid injection to cyclone-centrifugal separation is automated, significantly shortening the single-sample separation time and greatly improving testing efficiency. This invention utilizes a spiral guide channel for cyclone classification, reverse spiral guide blades for centrifugal separation, and a conical centrifugal screen for final retention. The coaxial arrangement of these three components achieves a smooth transition of the force field from cyclone to centrifugation, eliminating backmixing caused by material transfer between traditional devices and improving separation accuracy and target component recovery rate. This invention injects a first heavy liquid of different densities into each layer of the spiral guide channel through a first injection mechanism, forming an axial density gradient field. This allows mineral particles of different densities to be separated step-by-step during their movement along the spiral guide channel due to the synergistic effect of centrifugal force and density gradient. The density gradient can be flexibly adjusted according to sample characteristics, resulting in significantly better separation accuracy and adaptability than traditional methods using heavy liquids of a single density. This invention employs a zircon-loving, hydrophobic modified coating on the surface of a conical centrifuge screen. This coating exhibits high affinity for zircon particles and low affinity for medium-heavy minerals. Under centrifugal force, the heavy liquid is rapidly ejected, while residual medium-heavy minerals are thrown back into the heavy liquid, effectively retaining the zircon particles. The synergistic effect of this coating with the axial density gradient field and centrifugal force field significantly improves the recovery rate and purity of zircon, bringing the test results as close as possible to the true grade value. This invention sets the drain filter screens corresponding to each ring of the spiral guide channel to have a filtration precision that is inversely adapted to the density of the first heavy liquid injected into that ring. This results in the drain filter screens of the rings with higher density having lower filtration precision and larger pore size, in order to offset the increase in drain resistance caused by the increased viscosity of the high-density heavy liquid. This makes the drain rate of each ring tend to be balanced, maintains the stability of the density gradient of the heavy liquid between each ring of the spiral guide channel, and prevents the heavy liquid in the previous ring from overflowing to the next ring due to poor drainage caused by viscosity differences. This invention sets the filtration precision of the drain filter screens in each ring of the spiral guide channel to decrease progressively along the material flow direction, with the filtration precision of the uppermost drain filter screen being smaller than the sieve aperture of the primary screening screen. This allows debris samples within the target particle size range to be effectively intercepted during their movement along the spiral guide channel, while mud and fine sand components can be discharged step by step through the drain channels of each ring. This maintains a stable density gradient while preventing the accumulation of fine impurities in the spiral guide channel, thus improving the accuracy of subsequent heavy liquid separation. Attached Figure Description

[0019] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the embodiments of the invention to explain the invention and do not constitute a limitation thereof.

[0020] In the attached diagram: Figure 1 This is a schematic diagram of the first orientation of a screening device for testing zircon grade in marine sandy sediments according to the present invention; Figure 2 This is a schematic diagram of the second orientation of a screening device for testing zircon grade in marine sandy sediments according to the present invention; Figure 3 This is a third-direction structural schematic diagram of a screening device for testing zircon grade in marine sandy sediments according to the present invention; Figure 4 This is a first partial cross-sectional view of a screening device for testing zircon grade in marine sandy sediments according to the present invention. Figure 5 This is a second partial cross-sectional view of a screening device for testing zircon grade in marine sandy sediments according to the present invention. Figure 6 This is a schematic diagram of the first disassembled structure of a screening device for testing zircon grade in marine sandy sediments according to the present invention; Figure 7 This is a schematic diagram of the second disassembled structure of a screening device for testing zircon grade in marine sandy sediments according to the present invention; Figure 8 This is a schematic diagram of the third disassembled structure of a screening device for testing zircon grade in marine sandy sediments according to the present invention; Figure 9 This is a schematic diagram of the first direction structure of the secondary screening mechanism in this invention; Figure 10 This is a schematic diagram of the second direction structure of the secondary screening mechanism in this invention; Figure 11 This is a schematic diagram of the first split structure of the secondary screening mechanism in this invention; Figure 12 This is a schematic diagram of the second split structure of the secondary screening mechanism in this invention; Figure 13 This is a schematic diagram of the first orientation structure of the first separation component in this invention; Figure 14 This is a schematic diagram of the second orientation structure of the first separation component in this invention; Figure 15 This is a schematic diagram of the first orientation structure of the second separation component in this invention; Figure 16 This is a schematic diagram of the first orientation structure of the second separation component in this invention; Figure 17 for Figure 4 A magnified structural diagram of point A in the middle.

[0021] In the diagram: 1-Base plate, 2-First heavy liquid storage tank, 3-First heavy liquid injection pump, 4-Mounting frame, 5-First-stage screening cylinder, 6-Waste liquid recovery tank, 7-Water storage tank, 8-Second heavy liquid storage tank, 9-Wastewater collection tank, 10-First-stage waste collection tank, 11-Second-stage screening cylinder, 12-Inlet, 13-Feeding pipe, 14-Peristaltic pump, 15-Second waste recovery tank, 16-First heavy liquid storage chamber, 17-Second heavy liquid supply... 18-Feed Pump, 29-Secondary Screening Motor, 20-Secondary Screening Shaft, 21-Annular Distribution Frame, 22-Fixed Cylinder, 23-Spiral Guide Channel, 24-Gradient Density Separation Ring, 25-Basin-shaped Collection Box, 26-Conical Centrifugal Screen, 27-First Heavy Liquid Conveying Pipe, 28-Second Heavy Liquid Conveying Pipe, 29-Water Supply Pipe, 30-First Waste Heavy Liquid Recovery Pipe, 31-Wastewater Recovery Pipe, 32-Second Waste Liquid Recovery Pipe, 33-Annular Heavy Liquid Distributor, 331-Second Heavy Liquid Nozzle, 34-Reverse Spiral Guide Blade, 35-Connecting Crossbar, 36-Connecting Vertical Bar, 37-Zircon Collection Box, 38-Output Pipe, 39-Second Waste Liquid Recovery Pipe, 40-Injection Pipe, 41-First-Stage Screening Motor, 42-Driving Bevel Gear, 43-Driven Bevel Gear I, 44-Driven Bevel Gear II, 45-Hollow Shaft, 46-Connector Rod, 47-First-stage screening screen, 48-Flexible plate, 49-Flexible corrugated plate, 50-Flexible corrugated plate rotating shaft, 51-Drainage channel, 52-Drainage filter screen, 53-First heavy liquid injection hole, 54-Fixed pipe, 55-Injection control valve, 56-Support pipe, 57-Wastewater recovery control valve, 58-Discharge guide frame, 60-First heavy liquid pipe, 61-Water supply pump, 62-Waste liquid collection vacuum pump, 63-Waste material collection vacuum pump. Detailed Implementation

[0022] 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. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0023] Example 1, as Figure 1-17 As shown, this embodiment provides a screening device for testing the zircon grade of marine sandy sediments, including a base plate 1. A secondary screening mechanism is provided on the base plate 1. The secondary screening mechanism performs a second screening process on the sample that has been screened by the primary screening mechanism to ensure the purity of the collected zircon. A primary screening mechanism is provided above the secondary screening mechanism. The primary screening mechanism screens the sediment sample to remove mud and fine sand components from the sediment and obtain detrital samples within the target particle size range. The secondary screening mechanism consists of a first separation component, a second separation component, and a third separation component; The first separation component includes a mounting frame 4 mounted on a base plate 1. A secondary screening cylinder 11 is mounted on the mounting frame 4. A spiral guide channel 22 is installed inside the secondary screening cylinder 11. Several first heavy liquid injection holes 53 are provided on the side wall of the spiral guide channel 22. A fixed pipe 54 is connected to one end of each first heavy liquid injection hole 53. The end of the fixed pipe 54 corresponding to each turn of the spiral guide channel 22 communicates with the inside of a first heavy liquid pipe 60. The inlet of the first heavy liquid pipe 60 is connected to a first injection mechanism. Except for the lowest turn, each turn of the spiral guide channel 22 has a drain point at its lowest point. Channel 51 is equipped with a drain filter 52, which allows the first heavy liquid to be discharged from the drain filter 52, preventing the heavy liquid in the previous ring from entering the heavy liquid in the next ring and affecting the density of the heavy liquid in the next ring. A waste liquid collection mechanism is connected to the lower side of the drain channel 51. A feeding mechanism is connected to the inlet of the spiral guide channel 22. An annular distribution frame 20 is connected to the lower part of the outlet of the spiral guide channel 22. The annular distribution frame 20 is installed in the secondary sieve cylinder 11. The annular distribution frame 20 has through holes arranged in a circular array to facilitate sample passage. The second separation component includes a secondary screening shaft 19 that is rotatably connected to the top of the secondary screening cylinder 11. The secondary screening shaft 19 is powered by a secondary screening motor 18 installed on the secondary screening cylinder 11. A fixed cylinder 21 is installed at the lower part of the annular distribution frame 20 and is connected to the bottom of the secondary screening cylinder 11. A reverse spiral guide vane 34 is fixedly installed on the outer surface of the secondary screening shaft 19. An annular heavy liquid distributor 33 is installed inside the fixed cylinder 21. A second heavy liquid nozzle 331 that communicates with the inside of the annular heavy liquid distributor 33 is uniformly machined on the annular heavy liquid distributor 33. A second liquid injection mechanism is connected to the annular heavy liquid distributor 33. A gradient density sorting ring 23 is installed inside the fixed cylinder 21 below the annular heavy liquid distributor 33 and is rotatably connected to the secondary screening shaft 19. The third separation component includes conical centrifugal screens 25 arranged in an array from top to bottom. The conical centrifugal screens 25 are connected by several connecting vertical rods 36. The conical centrifugal screens 25 are rotatably installed in the fixed cylinder 21. The upper conical centrifugal screens 25 are connected to one end of a connecting horizontal rod 35, and the other end of the connecting horizontal rod 35 is connected to the lower end of the secondary screening shaft 19. The drain filter screens 52 corresponding to each ring of the spiral guide channel 22 have a filtration precision that is inversely adapted to the density of the first heavy liquid injected into that ring. Since the viscosity of the high-density heavy liquid is significantly greater than that of the low-density heavy liquid, if drain filters with the same filtration precision are used, the drain resistance of the high-density ring will be significantly greater than that of the low-density ring, resulting in uneven drain rates among the rings. The high-density heavy liquid in the previous ring overflows into the next ring due to poor drainage, disrupting the stability of the axial density gradient field. To resolve this specific physical contradiction, this invention sets the filtration precision of the drain filter screens 52 of the denser rings to be lower and the pore size to be larger, thus offsetting the increased drain resistance caused by the increased viscosity of the high-density heavy liquid. This allows each ring to achieve a more balanced drain rate under the same suction pressure of the waste liquid collection vacuum pump 62, thereby passively maintaining the stability of the density gradient of the heavy liquid among the rings of the spiral guide channel 22 at the structural level. Meanwhile, the filtration accuracy of the drain filter screens 52 in each ring of the spiral guide channel 22 decreases progressively along the material flow direction, and the filtration accuracy of the uppermost drain filter screen 52 is smaller than the sieve aperture of the primary screening screen 47. This ensures that the debris sample within the target particle size range that enters the spiral guide channel 22 after primary screening is effectively intercepted by the drain filter screens 52 at each level during its movement along the spiral guide channel 22, while smaller mud and fine sand components can pass through the drain filter screens 52 and be discharged with the waste heavy liquid through the drain channel 51, avoiding the accumulation of fine impurities in the spiral guide channel 22. This maintains a stable density gradient while improving the accuracy of subsequent heavy liquid separation. During operation, the debris sample enters the spiral guide channel 22. A first heavy liquid is injected into the spiral guide channel 22 through the first injection mechanism, resulting in different heavy liquid densities in each layer of the spiral guide channel 22, forming an axial density gradient field. As the debris sample moves within the spiral guide channel 22, due to centrifugal force and the axial density gradient field, components with a density less than the heavy liquid density float to the position of the first waste recovery pipe 28, while components with a density greater than the heavy liquid density move downwards along the spiral guide channel 22. The sample flows out from the bottom and is distributed by the annular distribution frame 20 before entering the fixed cylinder 21. When the first heavy liquid in each circle of the spiral guide channel 22 reaches the lowest point of each circle, it is filtered and discharged through the drain filter screen 52 to prevent the sample from being discharged. The sample continues to move along the spiral guide channel 22. By timely discharging the first heavy liquid in each circle, it is prevented that the first heavy liquids in the different circles correspond to each other, which would affect the density and affect the screening process of the sample. Timely discharge also increases the flow rate of the heavy liquid and improves the screening speed. The secondary screening motor 18 is started, which drives the secondary screening shaft 19 to rotate, thereby driving the reverse spiral guide vane 34 to rotate. At the same time, the second heavy liquid is introduced into the annular heavy liquid distributor 33 through the second liquid injection mechanism. The heavy liquid is sprayed upward at a certain angle through the second heavy liquid nozzle 331, and different angles of spraying are achieved. The reverse spiral guide vane 34 rotates, which drives the heavy mineral combination and the heavy liquid to mix thoroughly, forming a uniform suspension. Under the action of centrifugal force generated by the rotation of the reverse spiral guide vane 34, mineral particles of different densities move towards the wall of the secondary screening cylinder 11. Due to the different particle size and density, their movement speed and trajectory are also different. The medium and heavy minerals with lower density move slower and fall into the inner and middle sorting holes of the basin-shaped collection box 24 for discharge. The heavy minerals with higher density move faster and fall into the outer sorting holes of the basin-shaped collection box 24 for discharge, and fall into the conical centrifugal screen 25. Increasing the speed of the secondary screening motor 18 drives the conical centrifugal screen 25 to rotate. Under the action of centrifugal force, the zircon particles are thrown outward and pass through different conical centrifugal screens 25 for classification and interception. The heavy liquid is thrown onto the wall of the secondary screening cylinder 11 and falls onto the bottom wall of the secondary screening cylinder 11. The zircon-loving hydrophobic modified coating on the surface of the conical centrifugal screen 25 can quickly separate the heavy liquid. The remaining small amount of medium and heavy minerals have low affinity with the coating and are thrown into the heavy liquid by centrifugal force. After separation, the speed of the secondary screening motor 18 is reduced, causing the zircon to slide down the inner side of the conical centrifugal screen 25 and be discharged through the collection mechanism.

[0024] Advantageously, the width of the spiral guide channel 22 decreases linearly from the initial end to the end, and the depth of the channel increases linearly from the initial end to the end; The second heavy liquid nozzles 331 on the same vertical plane are a group, and there are multiple groups. The spray angle of the second heavy liquid nozzles 331 in each group is different. The basin-shaped collection box 24 has several rings of sorting holes along the radial direction, and the radius of the sorting holes increases from the inside to the outside. The aperture of each conical centrifugal screen 25 is different and decreases from top to bottom. The outer surface of the conical centrifugal screen 25 is provided with a zircon-loving hydrophobic modified coating.

[0025] Advantageously, the primary screening mechanism includes a primary screening cylinder 5 mounted on the top of the mounting frame 4, a primary screening motor 41 mounted on the top of the primary screening cylinder 5, a driving bevel gear 42 fixedly connected to the end of the output shaft of the primary screening motor 41, the driving bevel gear 42 meshing with driven bevel gear 1 43 and driven bevel gear 2 44, driven bevel gear 2 44 fixedly mounted on the upper end of the hollow shaft 45, several connecting rods 46 fixedly connected to the lower end of the hollow shaft 45, a primary screening screen 47 mounted on the end of the connecting rods 46, the primary screening screen 47 rotatably mounted inside the primary screening cylinder 5, the hollow shaft 45 rotatably mounted through the top of the primary screening cylinder 5, driven bevel gear 1 43 fixedly mounted on the upper end of the flexible corrugated plate rotating shaft 50, the flexible corrugated plate rotating shaft 50 rotatably mounted through the hollow shaft 45, several flexible corrugated plates 49 fixedly mounted on the outer surface of the flexible corrugated plate rotating shaft 50, and several flexible plates 48 mounted on the inner side of the primary screening screen 47; The top of the primary screening cylinder 5 is equipped with a feed inlet 12; The primary screening mechanism also includes a water supply component, which includes a water storage tank 7 installed on the base plate 1, a water supply pump 61 installed on the water storage tank 7, and the inlet of the water supply pump 61 is connected to the inside of the water storage tank 7. The outlet of the water supply pump 61 is connected to one end of a water supply pipe 29, and the other end of the water supply pipe 29 is connected to the inside of the primary screening cylinder 5. The primary screening mechanism also includes a wastewater recovery component, which includes a wastewater recovery pipe 31 connected to the lower part of the primary screening cylinder 5. The end of the wastewater recovery pipe 31 is connected to a wastewater collection tank 9, which is installed on the bottom plate 1. A wastewater recovery control valve 57 is connected in series on the wastewater recovery pipe 31. The inner bottom wall of the primary screening cylinder 5 is inclined towards the connection of the wastewater recovery pipe 31. During operation, sediment samples taken from the seabed are injected into the primary screening cylinder 5 through the feed inlet 12. The water supply pump 61 is started to pump the cleaning water in the water storage tank 7 into the primary screening cylinder 5 through the water supply pipe 29. At the same time, the primary screening motor 41 is started. The output shaft of the primary screening motor 41 rotates, driving the active bevel gear 42 to rotate. The active bevel gear 42 meshes with the driven bevel gear 1 43 and the driven bevel gear 2 44, thereby driving the hollow shaft 45 and the flexible corrugated plate shaft 50 to rotate in opposite directions. This causes the primary screening screen 47 to rotate, and the flexible plate 48 and the flexible corrugated plate 49 to rotate in opposite directions. This improves the efficiency of stirring and separation, allowing the mud and fine sand components to separate from the debris samples within the target particle size range. The mud and fine sand components pass through the primary screening screen 47 and enter the primary screening cylinder 5. After cleaning, the wastewater from the primary screening cylinder 5 is discharged, and the debris samples within the target particle size range remain on the primary screening screen 47.

[0026] Advantageously, the injection mechanism is used to inject the sample after primary screening into the spiral guide channel 22. The injection mechanism includes an injection pipe 40 installed on the secondary screening cylinder 11. The inlet of the injection pipe 40 is connected to the outlet of the peristaltic pump 14. The inlet of the peristaltic pump 14 is connected to one end of the conveying pipe 13. The other end of the conveying pipe 13 is connected to the support pipe 56. The support pipe 56 is installed on the primary screening cylinder 5 and its upper part is rotatably connected to the lower part of the primary screening screen 47. An injection control valve 55 is connected in series on the support pipe 56. The outlet of the injection pipe 40 extends to the inlet of the spiral guide channel 22 and is tangentially set along the inlet of the spiral guide channel 22. A drying cylinder is connected in series on the 13 so that the sample is dried when it passes through the drying cylinder to remove the moisture in the sample and prevent it from affecting subsequent screening. During operation, the injection control valve 55 is opened, the primary screening motor 41 is stopped, and the debris sample within the target particle size range falls through the primary screening screen 47, enters the support pipe 56 through the injection control valve 55, and then enters the conveying pipe 13. After being dried in the drying cylinder, the peristaltic pump 14 is started to peristalse and transport the debris sample into the injection pipe 40, and then into the spiral guide groove 22 through the injection pipe 40.

[0027] Advantageously, the first injection mechanism is used to inject the first heavy liquid into the spiral guide channel 22 to achieve density gradient control. The first injection mechanism includes a first heavy liquid storage tank 2 installed on the base plate 1. The first heavy liquid storage tank 2 is provided with a plurality of first heavy liquid storage chambers 16. Each first heavy liquid storage chamber 16 stores first heavy liquid of different densities. A first heavy liquid injection pump 3 is installed on the end wall of the first heavy liquid storage chamber 16. The inlet of the first heavy liquid injection pump 3 is connected to the inside of the first heavy liquid storage chamber 16. The outlet of the first heavy liquid injection pump 3 is connected to one end of the first heavy liquid delivery pipe 26. The other end of the first heavy liquid delivery pipe 26 is connected to the first heavy liquid pipe 60. During operation, the debris sample enters the spiral guide channel 22, and all the first heavy liquid injection pumps 3 are started to extract the first heavy liquid of different densities in the first heavy liquid storage chamber 16. The first heavy liquid enters the first heavy liquid pipe 60 through the first heavy liquid delivery pipe 26, enters the first heavy liquid injection hole 53 through the fixed pipe 54, and enters the spiral guide channel 22 through the first heavy liquid injection hole 53. This makes the heavy liquid density different in each turn of the spiral guide channel 22, forming an axial density gradient field. When the first heavy liquid enters from the side wall of the spiral guide channel 22, it will push the sample to move, improving the floating efficiency of samples with a density lower than that of the first heavy liquid.

[0028] Advantageously, the second injection mechanism is used to inject the second heavy liquid into the annular heavy liquid distributor 33 to ensure the injection pressure. The second injection mechanism includes a second heavy liquid storage tank 8 installed on the base plate 1. The second heavy liquid storage tank 8 stores the second heavy liquid. A second heavy liquid supply pump 17 is installed on the second heavy liquid storage tank 8. The inlet of the second heavy liquid supply pump 17 is connected to the inside of the second heavy liquid storage tank 8. The outlet of the second heavy liquid supply pump 17 is connected to one end of a second heavy liquid delivery pipe 27. The other end of the second heavy liquid delivery pipe 27 is connected to the inside of the annular heavy liquid distributor 33. During operation, the second heavy liquid supply pump 17 is started to extract the second heavy liquid from the second heavy liquid storage tank 8, so that the second heavy liquid enters the annular heavy liquid distributor 33 through the second heavy liquid delivery pipe 27 and is sprayed out through the second heavy liquid nozzle 331.

[0029] Advantageously, the waste liquid collection mechanism is used to collect the waste heavy liquid in the secondary screening. The waste liquid collection mechanism includes a first waste heavy liquid recovery pipe 30 connected to the lower part of the discharge channel 51, the other end of the first waste heavy liquid recovery pipe 30 connected to the waste liquid recovery tank 6, a waste liquid collection vacuum pump 62 installed on the waste liquid recovery tank 6, a second waste liquid recovery pipe 32 connected to the waste liquid recovery tank 6, the other end of the second waste liquid recovery pipe 32 connected to the lower part of the secondary screening cylinder 11 and communicating with the inside of the fixed cylinder 21. During operation, the waste liquid collection vacuum pump 62 is started to evacuate the waste liquid recovery tank 6, so that the heavy liquid on the bottom wall of the fixed cylinder 21 and the corresponding ore are sucked into the waste liquid recovery tank 6 through the second waste liquid recovery pipe 32, and the heavy liquid in the spiral guide channel 22 is sucked into the waste liquid recovery tank 6 through the first waste heavy liquid recovery pipe 30.

[0030] Advantageously, the waste collection mechanism is used to collect the waste ore screened out during the secondary screening process. The secondary screening cylinder 11 is connected to the waste collection mechanism, which includes a first waste collection component and a second waste collection component. The first waste collection assembly includes one end of a first waste recovery pipe 28 installed on the secondary screening cylinder 11, with the inlet extending to the position of the first heavy liquid injection hole 53 near the uppermost side. The other end of the first waste recovery pipe 28 is connected to the primary waste collection tank 10. The primary waste collection tank 10 is installed on the base plate 1, and a waste collection vacuum pump 63 is installed on the primary waste collection tank 10. The second waste collection assembly includes a basin-shaped collection box 24 connected to the lower part of the gradient density sorting ring 23, a second waste recovery pipe 39 connected to the bottom of the basin-shaped collection box 24 on one side, and the other end of the second waste recovery pipe 39 connected to the inside of the second waste recovery tank 15. The second waste recovery tank 15 is mounted on the mounting frame 4. The bottom wall of the basin-shaped collection box 24 is inclined toward the connection of the second waste recovery pipe 39. The wastewater recovery control valve 57 is inclined to facilitate the movement of the collected ore. During operation, the waste collection vacuum pump 63 is started to create a vacuum in the primary waste collection tank 10, causing the impurity sample that floats to the position of the first waste recovery pipe 28 to be sucked into the primary waste collection tank 10 through the first waste recovery pipe 28. The ore collected in the basin-shaped collection box 24 slides down the bottom wall of the basin-shaped collection box 24 and enters the second waste recovery pipe 39. After passing through the second waste recovery pipe 39, it enters the second waste recovery tank 15 for collection. In conjunction with the movement of the collected heavy liquid, the collected ore enters the second waste recovery tank 15 for collection more effectively.

[0031] Advantageously, a collection mechanism is connected to the lower part of the conical centrifugal screen 25. The collection mechanism is used to collect the screened zircons, which facilitates subsequent testing of the zircon grade. The collection mechanism includes an output pipe 38 rotatably connected to the lower part of the conical centrifugal screen 25. The length and diameter of the output pipes 38 connected to the conical centrifugal screen 25 decrease sequentially from top to bottom. The output pipes 38 are concentrically arranged and pass through the bottom of the secondary screening cylinder 11. Except for the output pipe 38 connected to the uppermost conical centrifugal screen 25, the lower part of the remaining output pipes 38 is connected to a discharge guide frame 58. The outlet position of each discharge guide frame 58 is different. The bottom wall of the discharge guide frame 58 is inclined along the outlet direction. A zircon collection box 37 is provided below the outlet of the discharge guide frame 58 and the outlet of the output pipe 38. The outermost one is installed on the secondary screening cylinder 11, and the inner output pipe 38 is connected to the discharge guide frame 58. During operation, the zircons collected on the upper connecting crossbar 35 are discharged through the central output pipe 38 into the zircon collection box 37 for collection. The remaining zircons on the connecting crossbar 35 enter the discharge guide frame 58 through the corresponding output pipe 38, and then enter the corresponding zircon collection box 37 for collection.

[0032] Advantageously, this device also includes a control system, which has corresponding control programs. The control system is electrically connected to the waste collection vacuum pump 63, the first heavy liquid injection pump 3, the waste liquid collection vacuum pump 62, the water supply pump 61, the secondary screening motor 18, the second heavy liquid supply pump 17, the wastewater recovery control valve 57, the primary screening motor 41, the injection control valve 55, and the peristaltic pump 14. The system controls and regulates the recovery control valve 57, the primary screening motor 41, the feeding control valve 55, and the peristaltic pump 14. During control and regulation, firstly, the water supply pump 61 is started to supply water. After a certain period of water supply, the water supply pump 61 is stopped. Next, the primary screening motor 41 is started, and its speed is adjusted. After the primary screening motor 41 has been running for a certain period, the wastewater recovery control valve 57 is opened to drain water. The wastewater recovery control valve 57 remains open until the next screening cycle, after which it is closed. The control valve 55 is opened, simultaneously starting the peristaltic pump 14. This causes the speed of the primary screening motor 41 to gradually decrease, facilitating better discharge of the screened sample. After the peristaltic pump 14 has been running for a certain period, the primary screening motor 41 is stopped. Simultaneously with the start of the peristaltic pump 14, all the first heavy liquid injection pumps 3 are started, and their speeds are adjusted to ensure a certain ratio between the injected material and the injected heavy liquid. At the same time as the first heavy liquid injection pumps 3 start, the waste liquid collection vacuum pump 62 is activated to ensure proper collection of waste heavy liquid. After the first heavy liquid injection pump 3 has been running for a certain period of time, the waste collection vacuum pump 63, the second heavy liquid supply pump 17, and the secondary screening motor 18 are started simultaneously. The speed of the secondary screening motor 18 is adjusted. After the secondary screening motor 18 has been running for a certain period of time, the first heavy liquid injection pump 3 and the peristaltic pump 14 are stopped. After the first heavy liquid injection pump 3 has been stopped for a certain period of time, the secondary screening motor 18 and the second heavy liquid supply pump 17 are stopped. After the second heavy liquid supply pump 17 has been stopped for a certain period of time, the waste collection vacuum pump 63 and the waste liquid collection vacuum pump 62 are stopped. In this invention, the first heavy liquid injection pump 3, the peristaltic pump 14, the waste collection vacuum pump 63, the waste liquid collection vacuum pump 62, the secondary screening motor 18, and the second heavy liquid supply pump 17 are all connected to the controller via signals. The core linkage control logic of the controller is as follows: The first layer of linkage control, axial density gradient field stabilization linkage: During the process of injecting first heavy liquid of different densities into each layer of the spiral guide channel 22 through the first heavy liquid injection pump 3 to form an axial density gradient field, the controller synchronously adjusts the feeding rate of the peristaltic pump 14 and the suction rate of the waste collection vacuum pump 63 to the first waste recovery pipe 28, so that the light components with a density less than the density of the heavy liquid in the current layer float up and are promptly pumped away, while the heavy components with a density greater than the density of the heavy liquid in the current layer move downward along the spiral guide channel 22; at the same time, the controller dynamically adjusts the suction rate of the waste collection vacuum pump 62 according to the injection flow rate of the first heavy liquid injection pump 3 and the discharge rate of the discharge channel 51, so as to maintain the stability of the density gradient of the heavy liquid in each layer of the spiral guide channel 22, and prevent the heavy liquid in the previous layer from overflowing to the next layer due to poor discharge, causing the axial density gradient field to collapse. Thus, mineral particles of different densities are precisely separated step by step during the movement along the spiral guide channel 22 due to the synergistic effect of centrifugal force and the stable axial density gradient field.

[0033] The second layer of linkage control, the overload prevention linkage of the conical centrifugal screen: During the rotation of the secondary screening motor 18 driving the reverse spiral guide vane 34 and the conical centrifugal screen 25, the controller judges the heavy mineral retention status on the surface of the conical centrifugal screen 25 based on the speed of the secondary screening motor 18 and the load current feedback; when the load current rises to the preset threshold, the controller simultaneously reduces the feed rate of the peristaltic pump 14 and / or increases the suction rate of the waste liquid collection vacuum pump 62 on the bottom of the fixed cylinder 21 to prevent the screen holes of the conical centrifugal screen 25 from being blocked due to heavy mineral overload, while ensuring that the zircon hydrophobic modified coating on the surface of the conical centrifugal screen 25 can always effectively retain zircon particles and throw the remaining medium and heavy minerals into the heavy liquid under the action of centrifugal force.

[0034] This invention provides a screening method for testing the zircon grade of marine sandy sediments, based on the aforementioned screening device for testing the zircon grade of marine sandy sediments, comprising the following steps: Step 1: The sediment sample taken from the seabed is injected into the primary screening cylinder 5 through the feed inlet 12. The water supply pump 61 is started to send the cleaning water in the water storage tank 7 into the primary screening cylinder 5 through the water supply pipe 29. At the same time, the primary screening motor 41 is started, which drives the active bevel gear 42 to rotate, thereby driving the hollow shaft 45 and the flexible corrugated plate shaft 50 to rotate in opposite directions. This causes the primary screening screen 47 to rotate, and the flexible plate 48 and the flexible corrugated plate 49 to rotate in opposite directions. This improves the efficiency of stirring and separation, and separates the mud and fine sand components from the debris samples within the target particle size range. The mud and fine sand components pass through the primary screening screen 47 and enter the primary screening cylinder 5. After cleaning, the wastewater in the primary screening cylinder 5 is discharged, and the debris samples within the target particle size range remain on the primary screening screen 47. Step 2: Open the injection control valve 55, stop the primary screening motor 41, and the debris sample within the target particle size range falls up and down the primary screening screen 47, enters the support tube 56 through the injection control valve 55, and then enters the conveying pipe 13. Start the peristaltic pump 14 to perform peristalsis, and transport the debris sample into the injection pipe 40, and then enters the spiral guide groove 22 through the injection pipe 40. Step 3: The debris sample enters the spiral guide channel 22. The first heavy liquid is injected into the spiral guide channel 22 through the first liquid injection mechanism, so that the heavy liquid density of each layer of the spiral guide channel 22 is different, forming an axial density gradient field. When the debris sample moves in the spiral guide channel 22, under the action of centrifugal force and axial density gradient field, the density of the debris sample is less than that of the heavy liquid and floats to the position of the first waste recovery pipe 28, while the density of the debris sample is greater than that of the heavy liquid and moves downward along the spiral guide channel 22, flows out through the lower side of the spiral guide channel 22, and enters the fixed cylinder 21 through the annular distribution frame 20. The secondary screening motor 18 is started, which drives the secondary screening shaft 19 to rotate, thereby driving the reverse spiral guide vane 34 to rotate. At the same time, the second heavy liquid is introduced into the annular heavy liquid distributor 33 through the second liquid injection mechanism and sprayed upward at a certain angle through the second heavy liquid nozzle 331. The reverse spiral guide vane 34 rotates, driving the heavy mineral combination and the heavy liquid to mix fully and form a uniform suspension. Under the action of centrifugal force, mineral particles of different densities move towards the wall of the secondary screening cylinder 11. Due to the different particle size and density, their movement speed and trajectory are also different. The medium and heavy minerals with lower density move slower and fall into the inner and middle sorting holes of the basin-shaped collection box 24 for discharge. The heavy minerals with higher density move faster and fall into the outer sorting holes of the basin-shaped collection box 24 for discharge and fall into the conical centrifugal screen 25. Increasing the speed of the secondary screening motor 18 drives the conical centrifugal screen 25 to rotate. Under the action of centrifugal force, the zircon particles are thrown outward and pass through different conical centrifugal screens 25 for classification and interception. The heavy liquid is thrown onto the wall of the secondary screening cylinder 11 and falls onto the bottom wall of the secondary screening cylinder 11. The zircon-loving hydrophobic modified coating on the surface of the conical centrifugal screen 25 can quickly separate the heavy liquid. The remaining small amount of medium and heavy minerals have low affinity with the coating and are thrown into the heavy liquid by centrifugal force. After separation, the speed of the secondary screening motor 18 is reduced, causing the zircon to slide down the inner side of the conical centrifugal screen 25 and be discharged through the collection mechanism.

[0035] Step 4: The debris sample enters the spiral guide channel 22, and the first heavy liquid injection pump 3 is started to extract the first heavy liquid of different densities in the first heavy liquid storage chamber 16. The sample enters the first heavy liquid pipe 60 through the first heavy liquid delivery pipe 26, enters the first heavy liquid injection hole 53 through the fixed pipe 54, and enters the spiral guide channel 22 through the first heavy liquid injection hole 53. This results in a different density of heavy liquid in each turn of the spiral guide channel 22, forming an axial density gradient field. Step 5: Start the second heavy liquid supply pump 17 to extract the second heavy liquid from the second heavy liquid storage tank 8, so that the second heavy liquid enters the annular heavy liquid distributor 33 through the second heavy liquid delivery pipe 27 and is sprayed out through the second heavy liquid nozzle 331. Step 6: Start the waste collection vacuum pump 63 to evacuate the primary waste collection tank 10, so that the impurity sample that floats to the position of the first waste recovery pipe 28 is sucked into the primary waste collection tank 10 through the first waste recovery pipe 28. The ore collected in the basin-shaped collection box 24 enters the second waste collection tank 15 through the second waste collection pipe 39 for collection. Step 7: Start the waste liquid collection vacuum pump 62 to evacuate the waste liquid recovery tank 6, so that the heavy liquid on the bottom wall of the fixed cylinder 21 and the corresponding ore are sucked into the waste liquid recovery tank 6 through the second waste liquid recovery pipe 32, and the heavy liquid in the spiral guide channel 22 is sucked into the waste liquid recovery tank 6 through the first waste heavy liquid recovery pipe 30. Step 8: The zircons collected on the upper connecting crossbar 35 are discharged into the zircon collection box 37 through the central output pipe 38. The remaining zircons on the connecting crossbar 35 enter the discharge guide frame 58 through the corresponding output pipe 38, and then enter the corresponding zircon collection box 37 for collection.

[0036] It should be noted that, in this document, 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 process, method, article, or apparatus.

[0037] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A screening device for testing zircon grade in marine sandy sediments, characterized in that: Includes a base plate (1), on which a secondary screening mechanism is provided, which consists of a first separation component, a second separation component, and a third separation component; The first separation component includes a mounting frame (4) on a base plate (1), a secondary screening cylinder (11) on the mounting frame (4), a spiral guide groove (22) inside the secondary screening cylinder (11), a plurality of first heavy liquid injection holes (53) on the spiral guide groove (22), a fixed pipe (54) on the first heavy liquid injection hole (53), and a fixed pipe (54) on each turn of the spiral guide groove (22). The fixed pipe (54) corresponding to each turn of the spiral guide groove (22) is connected to the first heavy liquid pipe (60). (22) Except for the lowest ring, each of the remaining rings has a drain channel (51) at its lowest point. A drain filter (52) is provided in the drain channel (51). An annular distribution frame (20) is provided at the lower part of the outlet of the spiral guide channel (22), and the annular distribution frame (20) is located in the secondary screening cylinder (11). The second separation component includes a secondary screening shaft (19) provided at the top of the secondary screening cylinder (11). The secondary screening shaft (19) and the secondary screening cylinder (11) are located in the secondary screening cylinder (11). 1) The secondary screening motor (18) is connected to the ring distribution frame (20). A fixed cylinder (21) is provided at the lower part of the ring distribution frame (20). A reverse spiral guide vane (34) is provided on the secondary screening shaft (19). An annular heavy liquid distributor (33) is provided inside the fixed cylinder (21). A second heavy liquid nozzle (331) communicating with the inside of the annular heavy liquid distributor (33) is provided on the annular heavy liquid distributor (33). The gradient density sorting ring (23) is located below the annular heavy liquid distributor (33). The third separation component includes conical centrifugal screens (25) arranged in an array from top to bottom. The conical centrifugal screens (25) are connected by several connecting vertical rods (36). The conical centrifugal screens (25) are located inside the fixed cylinder (21). A connecting horizontal rod (35) is connected to the upper conical centrifugal screen (25). The connecting horizontal rod (35) is connected to the secondary screening shaft (19).

2. The screening device for zircon grade testing of marine sandy sediments according to claim 1, characterized in that: The width of the spiral guide groove (22) decreases linearly from the initial end to the end, and the depth of the groove increases linearly from the initial end to the end. The second heavy liquid nozzles (331) on the same vertical plane are a group, and there are multiple groups. The spray angle of the second heavy liquid nozzles (331) in each group is different. The basin-shaped collection box (24) has several rings of sorting holes along the radial direction, and the radius of the sorting holes increases from the inside to the outside. The aperture of each conical centrifugal screen (25) is different and decreases from top to bottom. The outer surface of the conical centrifugal screen (25) is provided with a zircon hydrophobic modified coating.

3. A screening device for testing zircon grade in marine sandy sediments according to claim 2, characterized in that: The upper part of the secondary screening mechanism is provided with a primary screening mechanism. The primary screening mechanism includes a primary screening cylinder (5) provided on the top of the mounting frame (4). A primary screening motor (41) is provided on the top of the primary screening cylinder (5). The output shaft of the primary screening motor (41) is provided with a driving bevel gear (42). The driving bevel gear (42) meshes with driven bevel gear one (43) and driven bevel gear two (44). Driven bevel gear two (44) is located on the upper end of the hollow shaft (45). The hollow shaft (45) is provided with several A connecting rod (46) is provided, and a primary screening screen (47) is provided on the connecting rod (46). The primary screening screen (47) is located inside the primary screening cylinder (5). A hollow shaft (45) is located at the top of the primary screening cylinder (5). A driven bevel gear (43) is located on the flexible corrugated plate rotating shaft (50). The flexible corrugated plate rotating shaft (50) is located inside the hollow shaft (45). Several flexible corrugated plates (49) are provided on the flexible corrugated plate rotating shaft (50). Several flexible plates (48) are provided on the inner side of the primary screening screen (47). The primary screening cylinder (5) is equipped with a feed inlet (12) at the top; The primary screening mechanism also includes a water supply component, which includes a water storage tank (7) on the base plate (1), a water supply pump (61) on the water storage tank (7), a water supply pipe (29) connected to the water supply pump (61), and the water supply pipe (29) communicating with the primary screening cylinder (5). The primary screening mechanism also includes a wastewater recovery component, which includes a wastewater recovery pipe (31) connected to the lower part of the primary screening cylinder (5). The wastewater recovery pipe (31) is connected to a wastewater collection tank (9), which is located on the bottom plate (1). A wastewater recovery control valve (57) is provided on the wastewater recovery pipe (31).

4. A screening device for testing zircon grade in marine sandy sediments according to claim 3, characterized in that: A material injection mechanism is connected to the spiral guide channel (22). The material injection mechanism includes a material injection pipe (40) provided on the secondary screening cylinder (11). The material injection pipe (40) is connected to the peristaltic pump (14). A material conveying pipe (13) is connected to the peristaltic pump (14). The material conveying pipe (13) is connected to the support pipe (56). The support pipe (56) is provided on the primary screening cylinder (5) and its top is connected to the lower part of the primary screening screen (47). A material injection control valve (55) is provided on the support pipe (56). The material injection pipe (40) extends to the inlet position of the spiral guide channel (22) and is tangentially set along the inlet of the spiral guide channel (22).

5. A screening device for testing zircon grade in marine sandy sediments according to claim 4, characterized in that: The inlet of the first heavy liquid pipe (60) is connected to the first liquid injection mechanism. The first liquid injection mechanism includes a first heavy liquid storage tank (2) installed on the base plate (1). The first heavy liquid storage tank (2) is provided with a number of first heavy liquid storage chambers (16). Each first heavy liquid storage chamber (16) stores first heavy liquid of different densities. A first heavy liquid injection pump (3) is installed on the end wall of the first heavy liquid storage chamber (16). The inlet of the first heavy liquid injection pump (3) is connected to the first heavy liquid storage chamber (16). The outlet of the first heavy liquid injection pump (3) is connected to a first heavy liquid delivery pipe (26). The first heavy liquid delivery pipe (26) is connected to the first heavy liquid pipe (60).

6. A screening device for testing zircon grade in marine sandy sediments according to claim 5, characterized in that: A second injection mechanism is connected to the annular heavy liquid distributor (33). The second injection mechanism includes a second heavy liquid storage tank (8) installed on the base plate (1). The second heavy liquid storage tank (8) stores the second heavy liquid. A second heavy liquid supply pump (17) is installed on the second heavy liquid storage tank (8). The inlet of the second heavy liquid supply pump (17) is connected to the inside of the second heavy liquid storage tank (8). The outlet of the second heavy liquid supply pump (17) is connected to a second heavy liquid delivery pipe (27). The second heavy liquid delivery pipe (27) is connected to the inside of the annular heavy liquid distributor (33).

7. A screening device for zircon grade testing of marine sandy sediments according to claim 6, characterized in that: A waste liquid collection mechanism is connected to the lower side of the drain channel (51). The waste liquid collection mechanism includes a first waste heavy liquid recovery pipe (30) connected to the lower part of the drain channel (51). The first waste heavy liquid recovery pipe (30) is connected to the waste liquid recovery tank (6). A waste liquid collection vacuum pump (62) is provided on the waste liquid recovery tank (6). A second waste liquid recovery pipe (32) is provided on the waste liquid recovery tank (6). The second waste liquid recovery pipe (32) is connected to the lower part of the secondary screening cylinder (11).

8. A screening device for testing zircon grade in marine sandy sediments according to claim 7, characterized in that: A waste collection mechanism is connected to the secondary screening cylinder (11), which includes a first waste collection component and a second waste collection component; The first waste collection assembly includes a first waste recovery pipe (28) installed on the secondary screening cylinder (11), the first waste recovery pipe (28) is connected to the primary waste collection tank (10), the primary waste collection tank (10) is located on the base plate (1), and the primary waste collection tank (10) is equipped with a waste collection vacuum pump (63). The second waste collection assembly includes a basin-shaped collection box (24) connected to the lower part of the gradient density sorting ring (23). The basin-shaped collection box (24) is provided with a second waste recycling pipe (39). The second waste recycling pipe (39) is connected to the inside of the second waste recycling tank (15). The second waste recycling tank (15) is located on the mounting frame (4).

9. A screening device for zircon grade testing of marine sandy sediments according to claim 8, characterized in that: A collection mechanism is provided at the bottom of the conical centrifugal screen (25). The collection mechanism includes an output pipe (38) connected to the bottom of the conical centrifugal screen (25). The length of the output pipes (38) connected to the conical centrifugal screen (25) decreases from top to bottom, and the diameter decreases from bottom to top. The output pipes (38) are arranged concentrically and pass through the bottom of the secondary screening cylinder (11). Except for the output pipe (38) provided on the uppermost conical centrifugal screen (25), the lower part of the remaining output pipes (38) is provided with a discharge guide frame (58). The outlet position of each discharge guide frame (58) is different. A zircon collection box (37) is provided on the lower side of the outlet of the discharge guide frame (58) and the outlet of the output pipe (38). The outermost one is installed on the secondary screening cylinder (11), and the inner output pipe (38) is connected to the discharge guide frame (58).

10. A screening method for zircon grade testing of marine sandy sediments, based on the screening device for zircon grade testing of marine sandy sediments as described in claim 9, characterized in that: step include: Step 1: The sediment sample taken from the seabed is injected into the primary screening cylinder (5) through the feed port (12). The water supply pump (61) is started to send the cleaning water in the water storage tank (7) into the primary screening cylinder (5) through the water supply pipe (29). At the same time, the primary screening motor (41) is started to drive the active bevel gear (42) to rotate, thereby driving the hollow shaft (45) and the flexible corrugated plate shaft (50) to rotate in opposite directions. This causes the primary screening screen (47) to rotate, and the flexible plate (48) and the flexible corrugated plate (49) to rotate in opposite directions. This improves the efficiency of stirring and separation, and separates the mud and fine sand components from the debris samples within the target particle size range. The mud and fine sand components pass through the primary screening screen (47) and enter the primary screening cylinder (5). After cleaning, the wastewater from the primary screening cylinder (5) is discharged, and the debris samples within the target particle size range remain on the primary screening screen (47). Step 2: Open the injection control valve (55), stop the primary screening motor (41), and the debris sample within the target particle size range falls up and down on the primary screening screen (47), enters the support pipe (56) through the injection control valve (55), and enters the conveying pipe (13). Start the peristaltic pump (14) to peristalse and transport the debris sample to the injection pipe (40), and enters the spiral guide groove (22) through the injection pipe (40). Step 3: The debris sample enters the spiral guide channel (22). The first heavy liquid is injected into the spiral guide channel (22) through the first liquid injection mechanism, so that the heavy liquid density of each layer of the spiral guide channel (22) is different, forming an axial density gradient field. When the debris sample moves in the spiral guide channel (22), under the action of centrifugal force and axial density gradient field, the density less than the heavy liquid density floats to the position of the first waste recovery pipe (28), and the density greater than the heavy liquid density moves downward along the spiral guide channel (22), flows out through the lower side of the spiral guide channel (22), and enters the fixed cylinder (21) through the annular distribution frame (20). Start the secondary screening motor (18), drive the secondary screening shaft (19) to rotate, drive the reverse spiral guide vane (34) to rotate, and at the same time, the second heavy liquid is injected into the annular heavy liquid distributor (33) through the second liquid injection mechanism. The second heavy liquid is sprayed upward at a certain angle through the second heavy liquid nozzle (331). The reverse spiral guide vane (34) rotates, driving the heavy mineral combination to mix fully with the heavy liquid to form a uniform suspension. Under the action of centrifugal force, mineral particles of different densities move towards the wall of the secondary screening cylinder (11). Due to the different particle size and density, their movement speed and trajectory are also different. The medium and heavy minerals with smaller density move slower and fall into the inner and middle sorting holes of the basin-shaped collection box (24) for discharge. The heavy minerals with larger density move faster and fall into the outer sorting holes of the basin-shaped collection box (24) for discharge and fall into the conical centrifugal screen (25). Increase the speed of the secondary screening motor (18) to drive the conical centrifugal screen (25) to rotate. Under the action of centrifugal force, the zircon particles are thrown to the outside and pass through different conical centrifugal screens (25) for classification and interception. The heavy liquid is thrown onto the wall of the secondary screening cylinder (11) and falls to the bottom wall of the secondary screening cylinder (11). The zircon-loving hydrophobic modified coating on the surface of the conical centrifugal screen (25) can make the heavy liquid separate quickly. The remaining small amount of medium and heavy minerals are thrown into the heavy liquid by centrifugal force due to their low affinity with the coating. After separation, reduce the speed of the secondary screening motor (18) so that the zircon slides down the inner side of the conical centrifugal screen (25) and is discharged through the collection mechanism. Step 4: The debris sample enters the spiral guide channel (22), and the first heavy liquid injection pump (3) is started to extract the first heavy liquid of different densities in the first heavy liquid storage chamber (16). The first heavy liquid enters the first heavy liquid pipe (60) through the first heavy liquid delivery pipe (26), enters the first heavy liquid injection hole (53) through the fixed pipe (54), and enters the spiral guide channel (22) through the first heavy liquid injection hole (53), so that the heavy liquid density of each turn of the spiral guide channel (22) is different, forming an axial density gradient field. Step 5: Start the second heavy liquid supply pump (17) to draw the second heavy liquid from the second heavy liquid storage tank (8), so that the second heavy liquid enters the annular heavy liquid distributor (33) through the second heavy liquid delivery pipe (27) and is sprayed out through the second heavy liquid nozzle (331); Step 6: Start the waste collection vacuum pump (63) to evacuate the first-stage waste collection tank (10), so that the impurity sample that floats to the position of the first waste recovery pipe (28) is sucked into the first-stage waste collection tank (10) through the first waste recovery pipe (28); The ore collected in the basin-shaped collection box (24) enters the second waste collection tank (15) through the second waste collection pipe (39) for collection; Step 7: Start the waste liquid collection vacuum pump (62) to evacuate the waste liquid recovery tank (6), so that the heavy liquid on the bottom wall of the fixed cylinder (21) and the corresponding ore are sucked into the waste liquid recovery tank (6) through the second waste liquid recovery pipe (32), and the heavy liquid in the spiral guide channel (22) is sucked into the waste liquid recovery tank (6) through the first waste heavy liquid recovery pipe (30); Step 8: The zircons collected on the upper connecting crossbar (35) are discharged into the zircon collection box (37) through the central output pipe (38). The remaining zircons on the connecting crossbar (35) enter the discharge guide frame (58) through the corresponding output pipe (38) and then enter the corresponding zircon collection box (37) for collection.

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