Inner cylinder type electric separator

Abstract

The inner cylinder type electric separator comprises a machine base, a separation cylinder is rotationally arranged on the machine base, a feeding mechanism, an electrostatic electrode mechanism and a sweeping assembly are arranged in the separation cylinder, the feeding mechanism is used for feeding materials to the inner wall of the separation cylinder, and the sweeping assembly is located on the side, in the rotation direction of the separation cylinder, of the electrostatic electrode mechanism; material receiving assemblies are arranged below the static electrode mechanism and the sweeping assembly, the static electrode mechanism is used for discharging semiconductor and conductor ore grains, and the sweeping assembly is used for discharging non-conductor ore grains. The inner barrel type electric separator has the advantages that minerals with larger particle sizes can be separated, coarse-fraction non-conductor mineral particles are prevented from being mixed into conductor mineral particles, coarse-fraction conductor mineral particles are prevented from being mixed into the non-conductor mineral particles, the separation precision is high, whole-fraction direct separation can be achieved, and the production process is simple.

Description

Technical Field

[0001] The present invention relates to the technical field of mineral processing equipment, in particular to an inner drum type electric separator. Background Art

[0002] Electrostatic separation is a mineral separation method that uses the electrical and mechanical forces acting on minerals in an electric field to separate them based on their varying electrical properties. Electrostatic separation is primarily used for the selection and purification of minerals such as coastal placer ore, primary ilmenite, and scheelite. It is also used in a variety of applications, including the recovery of valuable metals from industrial and domestic waste and the removal of unburned carbon from fly ash in coal-fired power plants. Drum-type corona separators and electrostatic separators are common types of electrostatic separation equipment and play an important role in my country's electrostatic separation production practices.

[0003] like Figure 1 As shown in the figure, the drum-type corona separator adopts a working mode of combining corona electric field and electrostatic field. High voltage DC is passed through the electrostatic electrode and the corona electrode, and the sorting cylinder is grounded. When the DC high voltage reaches a certain value, a corona discharge electric field is generated between the corona electrode and the sorting cylinder; and an electrostatic electric field is generated between the electrostatic electrode and the sorting cylinder. During sorting, the ore to be sorted is fed onto the sorting cylinder and enters the corona discharge zone as it rotates. The corona current causes all mineral particles (including conductive and non-conductive mineral particles) to be negatively charged. Since the contact resistance between the conductive mineral particles and the sorting cylinder is small, their charge is quickly transferred through the grounded cylinder surface. Under the combined action of gravity and mechanical force, they are thrown away from the sorting cylinder and fall into the conductive ore receiving trough. The contact resistance between the non-conductive mineral particles and the sorting cylinder is large, and it is not easy to transfer the charge. Due to the action of electricity, they are adsorbed on the surface of the sorting cylinder and are carried to the other side as it rotates. They are brushed into the non-conductive ore receiving trough by the rolling brush. Semiconductive mineral particles fall into the semiconductor ore receiving trough because their charge transfer time is between that of conductors and non-conductive particles.

[0004] Normally, the surface of the separation cylinder is very smooth, and the friction between the conductive mineral particles and the cylinder can be ignored. The electrostatic electrode is set in a position to "deflect" the conductive mineral particles (hence the static electrode is also called the deflection electrode). That is, after the conductive mineral particles are thrown out of the cylinder, they enter the electrostatic field between the electrostatic electrode and the cylinder. Due to electrostatic induction, the conductive mineral particles are attracted by the electrostatic electrode, and their movement trajectory deviates further from the cylinder. Before they are thrown out of the separation cylinder, the electrostatic induction force (f GY ) is very small and can be ignored. Figure 4 As shown in the figure, the forces acting on the mineral particles are mainly gravity (mg), Coulomb force (f KL ), mirror force (f JX ), centrifugal force (f LX These four forces have the following effects on the behavior of mineral particles on the surface of the separation cylinder: Gravity (mg): The gravity acting on the mineral particle with mass m is mg, g is the acceleration of gravity. During the whole sorting process, the radial component of gravity (mg) J and tangential force (mg) Q It is constantly changing. Starting roughly from point A, the tangential component of gravity (mg) Q It plays the role of moving the mineral particles along the surface of the cylinder or leaving the cylinder. However, starting from point B, regardless of the tangential component of gravity (mg) Q Or its radial component (mg) J , all play the above roles.

[0005] Coulomb force (f KL ): The force on a mineral particle with a charge Q in a uniform electric field with an electric field strength of E is called the Coulomb force, which is equal to the product of its charge and the electric field strength. KL The direction is the normal direction of the cylinder surface and points to the center of the circle, so that the charged mineral particles are closely attached to the cylinder surface. For the conductive mineral particles, after contacting the grounded cylinder surface, Q is zero and the Coulomb force f KL For non-conductor and semiconductor mineral particles, the Coulomb force f KL It only works within the ABC region. At other points on the cylinder, the Coulomb force is very small because the electric field is very weak.

[0006] Mirror force (f JX ): Mirror force (also known as "interface attraction") is the residual charge Qs on the surface of the charged mineral particles and the induced charge at the corresponding position on the surface of the cylinder (such as Figure 5 The dotted line shows the attraction between the two (equal in magnitude and opposite in sign to Qs). JX The direction of action is the normal direction of the cylinder surface and points to the center of the circle, so that the mineral particles are tightly attached to the cylinder surface.

[0007] Centrifugal force (f LX ): Due to Coulomb force f KL and the mirror force f JX The semiconductor and non-conductor mineral particles adsorbed on the surface of the cylinder are subjected to centrifugal force due to the rotation of the cylinder. In sections ABCDE, together with gravity, they act to separate the semiconductor and non-conductor mineral particles from the cylinder. The conductive mineral particles only slide on the surface of the cylinder and are not affected by the centrifugal force.

[0008] After the mineral particles enter the corona electric field and are charged, the charge on the conductor mineral particles is quickly released through the surface of the cylinder, and the residual charge Qs is almost zero. The Coulomb force f acting on them is KL and the mirror force f JXVery small, due to the effect of gravity, in the ABC area, it breaks away from the cylinder and falls into the conductor material assembly. However, the charge obtained by the semiconductor (including the inclusion or conjoined body of conductor and non-conductor) mineral particles is released slowly or not easily, and the Coulomb force f generated by the residual charge is KL and the mirror force f JX It is adsorbed on the cylinder and moves in a circular motion, thus generating a centrifugal force f related to the cylinder speed. LX When the particle size of the selected mineral is coarse, such as the Coulomb force f KL and the mirror force f JX Not enough to counteract the centrifugal force f LX When the sum of the gravity mg force is added, semiconductor and non-conductor mineral particles will also fall into the conductive products.

[0009] Therefore, since the electric force, gravity and centrifugal force acting on the ore particles are closely related to the size of the ore particles, the electrostatic separation process of the drum-type corona separator is extremely sensitive to the unevenness of the ore particle size. Figure 6 As shown in the figure, the curve calculated by A.M. Gaudin for quartz particles shows the magnitude change of the force (in dynes) on the vertical axis and the change of the particle size on the horizontal axis. It can be seen that when the particle size of the quartz particles exceeds a certain value (i.e. Figure 6 At the vertical dashed line in the middle, gravity becomes stronger than electricity (the dashed line represents the gravity curve, the solid line represents the electricity curve). At this point, the behavior of the ore particles is determined by gravity, not electricity. In electrostatic separation of metal ores, the optimal separation particle size range is 0.1mm-0.4mm. When the particle size reaches 0.5mm, non-conductor particles will become noticeable among the conductive particles. When the particle size reaches 0.6mm (approximately 25 mesh), the quality of the conductive product becomes unacceptable.

[0010] On the one hand, due to the fact that conductors and non-conductors must be separated into individual components, it is difficult to achieve a satisfactory degree of separation in electrostatic separation practice, so it is generally not considered. However, in the particle size range of 0.5mm-2mm, there is a large demand for electrostatic separation applications in areas such as impurity removal of high-purity metals, recovery of valuable metals from PCB boards and scrap wire crushed materials, separation of zirconium and titanium from seashore sand and river sand, and separation of tungsten and tin. The defect that coarse particles of non-conductors are easily mixed into conductor products makes drum-type corona separators difficult to perform separation within the above-mentioned particle size range. On the other hand, due to the dominant effects of centrifugal force and gravity, coarse ore particles are preferentially enriched in conductor products, while due to the dominant effect of electricity, fine ore particles are preferentially enriched in non-conductor products. In order to avoid excessive particle size classification, materials often need to be screened before selection to narrow the particle size range. For example, rare metal minerals are usually divided into particle sizes of -30+60, -60+100, -100+150, and -150+200 mesh; non-ferrous metal minerals are usually divided into particle sizes of -30+100, -100+150, and -150+200 mesh. Although narrow-grade selection can improve sorting indicators, the process is very complicated and increases production costs.

[0011] like Figure 2 and Figure 3 As shown, Figure 2 It is an arc plate type electrostatic separator. Figure 3 This sieve-plate electrostatic separator is primarily used for purifying zirconium products from coastal sand deposits, particularly where high levels of non-conductors are present. Under the influence of gravity, the ore particles to be separated flow along a grounded plate into the electrostatic field generated by a large, curved, high-voltage electrode. Conductive particles are drawn toward the charged large, curved, high-voltage electrode, separating them from the non-conductors. Because fine particles are more affected by the electric field than coarse particles, fine conductors predominate in the conductive product, while coarser non-conductive particles are preferentially separated into the non-conductive product. Furthermore, due to the weak electrostatic force, coarse conductive material can easily mix into the non-conductive product. Summary of the Invention

[0012] The technical problem to be solved by the present invention is to overcome the shortcomings of the existing technology and provide an inner drum electric separator that can sort minerals with coarser particle sizes, prevent coarse non-conductive mineral particles from mixing into conductive mineral particles, and prevent coarse conductive mineral particles from mixing into non-conductive mineral particles. It has high sorting accuracy, can directly sort all particle sizes, and has a simple production process.

[0013] In order to solve the above technical problems, the present invention adopts the following technical solutions: An inner drum electric separator comprises a machine base, on which a sorting drum is rotatably arranged, wherein a feeding mechanism, an electrostatic electrode mechanism and a sweeping brush assembly are arranged in the sorting drum, wherein the feeding mechanism is used to feed material to the inner wall of the sorting drum, and the sweeping brush assembly is located on one side of the electrostatic electrode mechanism along the rotation direction of the sorting drum, and a material receiving assembly is provided below the electrostatic electrode mechanism and the sweeping brush assembly, wherein the electrostatic electrode mechanism is used to unload semiconductor and conductor mineral particles, and the sweeping brush assembly is used to unload non-conductor mineral particles.

[0014] As a further improvement of the above technical solution: The separation drum is further provided with a corona electrode mechanism located on the side of the electrostatic electrode mechanism opposite to the rotation direction of the separation drum, and a corona discharge area is formed between the corona electrode mechanism and the inner wall of the separation drum.

[0015] The electrostatic electrode mechanism includes a first electrostatic electrode and a second electrostatic electrode. A first electrostatic field region is formed between the first electrostatic electrode and the inner wall of the sorting drum to unload the conductor mineral particles. A second electrostatic field region is formed between the second electrostatic electrode and the inner wall of the sorting drum to unload the semiconductor mineral particles. The material receiving components are respectively provided below the first electrostatic electrode and the second electrostatic electrode. The first electrostatic electrode is located between the second electrostatic electrode and the corona electrode mechanism.

[0016] The speed of the separation drum is n, which satisfies , where D is the rotation diameter of the center of mass of the largest mineral particle in circular motion around the center of the separation drum.

[0017] The second electrostatic electrode is located just below the highest point of the inner wall of the sorting drum.

[0018] The first electrostatic electrode and the second electrostatic electrode are both electrostatic tubes, which are arranged along the axial direction of the sorting drum and can rotate around their own axes.

[0019] The sweeping brush assembly comprises a brush arranged along the axial direction of the sorting drum and a brush driving member for driving the brush to rotate. The rotation direction of the brush is opposite to that of the sorting drum.

[0020] The material receiving assembly comprises a material receiving hopper and a spiral ore discharger arranged at the bottom of the material receiving hopper, and the material receiving hopper and the spiral ore discharger are both arranged along the axial direction of the sorting drum.

[0021] The feeding mechanism comprises a spiral feeder arranged along the axial direction of the sorting drum and a feeding hopper arranged at the bottom of the spiral feeder, and a vibrating member is provided on the feeding hopper.

[0022] A plurality of rotating supporting wheels are provided on the machine base, the sorting drum is provided on the rotating supporting wheels, and the outer wall of the sorting drum is provided with supporting wheel grooves matched with the rotating supporting wheels to limit the axial position of the sorting drum.

[0023] Compared with the prior art, the advantages of the present invention are: 1. Compared with the traditional arc plate and sieve plate electrostatic separators, the inner drum type electrostatic separator of the present invention selectively separates the mineral particles by using the inner wall of the separation drum. The electrostatic induction force f GY As the dominant force in sorting, the electrostatic separation process is less sensitive to the unevenness of mineral particle size, making it possible to sort minerals with coarser particle sizes and prevent coarse-grained conductive mineral particles from mixing into non-conductive mineral particles, resulting in high sorting accuracy. There is no need to classify the mineral particles in advance, and all particle sizes can be directly sorted, simplifying the production process. Moreover, within a certain range, it can replace eddy current magnetic separators for non-ferrous materials, with a large processing capacity and low manufacturing cost.

[0024] 2. Compared with the traditional drum type high voltage electric separation, the inner drum type electric separator of the present invention selectively separates the mineral particles by using the inner wall of the separation drum. Since most or all of the gravity mg of the mineral particles is removed by the centrifugal force f LX The electric power becomes the dominant force in the separation, which enables the separation of coarser-sized minerals and prevents the mixing of coarse-grained non-conductive mineral particles into the conductive mineral particles, resulting in high separation accuracy. There is no need to classify the mineral particles in advance, and all particle sizes can be directly separated, simplifying the production process.

[0025] 3. In the inner drum type electric separator of the present invention, when unloading non-conductive mineral particles, the brush is in close contact with the inner wall of the separation drum, and the brush driving member drives the brush to unload the non-conductive mineral particles. Since the rotation direction of the brush is opposite to that of the separation drum, the brush can more effectively sweep the non-conductive mineral particles and the mineral particles can be unloaded more thoroughly.

[0026] 4. The inner drum type electrostatic separator of the present invention can unload the mineral particles accumulated on the electrostatic tube by rotating the electrostatic tube around its own axis, thereby preventing the corresponding electrostatic field from being deformed due to the accumulation of mineral particles and affecting the sorting effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is an axial view of an existing drum-type corona separator.

[0028] Figure 2 It is a structural diagram of an existing arc plate type electrostatic separator.

[0029] Figure 3 It is a structural diagram of an existing sieve plate type electrostatic separator.

[0030] Figure 4 This is an analysis diagram of the forces acting on mineral particles during the electrostatic separation process of an existing drum-type corona separator.

[0031] Figure 5 It is a schematic diagram of the mirror effect of charged mineral particles in the existing drum corona separator.

[0032] Figure 6 It is the AMGaudin curve.

[0033] Figure 7 This is an axial view of the inner drum type electric separator according to the first embodiment of the present invention.

[0034] Figure 8 This is a force analysis diagram of mineral particles in the inner drum type electric separator according to the first embodiment of the present invention.

[0035] Figure 9 This is an axial view of the inner drum type electric separator according to the second embodiment of the present invention.

[0036] Figure 10 This is a force analysis diagram of mineral particles in the inner drum type electric separator of the second embodiment of the present invention.

[0037] Figure 11 This is a schematic diagram of the movement trajectory of conductive mineral particles when the inner drum type electrostatic separator of the second embodiment of the present invention is not provided with the first electrostatic electrode.

[0038] Figure 12 This is a schematic diagram of the movement trajectory of conductive mineral particles when the first electrostatic electrode is provided in the inner drum type electrostatic separator of the second embodiment of the present invention.

[0039] The numbers in the figure represent: 1. Machine base; 11. Rotating support wheel; 2. Sorting drum; 3. Feeding mechanism; 31. Spiral feeder; 32. Feeding hopper; 33. Vibrating member; 4. Electrostatic electrode mechanism; 41. First electrostatic electrode; 42. Second electrostatic electrode; 5. Sweeping brush assembly; 51. Brush; 6. Material receiving assembly; 61. Material receiving hopper; 62. Spiral discharger; 7. Corona electrode mechanism; 71. Arc corona frame; 72. Corona wire assembly. DETAILED DESCRIPTION

[0040] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0041] In the description of the present invention, it should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention.

[0042] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature identified as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "plurality" means two or more, unless otherwise specifically defined.

[0043] In the present invention, unless otherwise expressly specified or limited, terms such as "assemble," "connect," "connect," and "fix" should be understood in a broad sense. For example, they may refer to fixed connection, detachable connection, or integration; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; and internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0044] Example 1: Figure 7 and Figure 8 The first embodiment of the present invention is shown. The inner drum type electric separator of this embodiment includes a machine base 1. A sorting drum 2 is rotatably arranged on the machine base 1. A feeding mechanism 3, an electrostatic electrode mechanism 4 and a sweeping brush assembly 5 are provided in the sorting drum 2. The feeding mechanism 3 is used to feed the material to the inner wall of the sorting drum 2. The sweeping brush assembly 5 is located on one side of the electrostatic electrode mechanism 4 along the rotation direction of the sorting drum 2 (such as Figure 7 As shown, the sorting drum 2 rotates clockwise, and the sweeping brush assembly 5 is located on the right side of the electrostatic electrode mechanism 4). A material receiving assembly 6 is provided below the electrostatic electrode mechanism 4 and the sweeping brush assembly 5. The electrostatic electrode mechanism 4 is used to unload semiconductor and conductor mineral particles, and the sweeping brush assembly 5 is used to unload non-conductor mineral particles.

[0045] The inner drum type electrostatic separator of this embodiment has no corona electrode and is an electrostatic separator type. It can be used to remove conductor and semiconductor impurities from non-conductor mineral particles, or to recover valuable metal materials from industrial waste. It is suitable for scenarios with high requirements for the quality of non-conductor mineral particles.

[0046] The working process is as follows: the feeding mechanism 3 feeds the material to the inner wall of the separation drum 2, and the mineral particles rotate with the separation drum 2 on the inner wall of the separation drum 2. During the electrostatic separation process, the rotation speed of the separation drum 2 is equal to the critical value of the mineral particles entering the centrifugal motion state. At this time, all the mineral particles just do not leave the inner wall of the separation drum 2. At the highest point of the inner wall, the centrifugal force on the mineral particles is equal to the gravity (ignoring the difference in the radius of the mineral particles) and the direction is opposite, that is, f LX = mg, the electrostatic electrode mechanism 4 is connected to the negative pole of the DC high voltage power supply, and the separation cylinder 2 is connected to the positive pole of the DC high voltage power supply and grounded at the same time. Since the mineral particles are not charged, the mineral particles are not affected by the Coulomb force f KL and the mirror force fJX When the mineral particles pass through the highest point of the inner wall, due to the electrostatic induction effect of the electrostatic electrode mechanism 4, the conductor and semiconductor mineral particles in the state of balance between centrifugal force and gravity will be attracted by the electrostatic electrode mechanism 4 and be affected by the electrostatic induction force f GY Due to the action of the electrostatic electrode mechanism 4, the particles fall off the inner wall and fall into the receiving assembly 6 below the electrostatic electrode mechanism 4, and are then transported to the outside of the sorting cylinder 2 by the receiving assembly 6. The non-conductor mineral particles continue to rotate with the sorting cylinder 2 to the sweeping brush assembly 5, and are swept by the sweeping brush assembly 5 to fall into the receiving assembly 6 below the sweeping brush assembly 5, and are then transported to the outside of the sorting cylinder 2 by the receiving assembly 6, thereby realizing the separation of the non-conductor mineral particles from the semiconductor and conductor mineral particles.

[0047] The working principle is as follows: suppose that all the mineral particles on the inner wall of the sorting drum 2 are a single layer, and the radius of gyration of the center of mass of the largest mineral particle making a circular motion around the center O of the sorting drum 2 is R, and the diameter is D. Let m be the mass of the single mineral particle, g be the acceleration of gravity, n be the number of revolutions per minute of the sorting drum 2, point H is the point when the mineral particles begin to separate from the inner wall of the sorting drum 2 when no electric field is applied, point Z is the highest point of the inner wall of the sorting drum 2, and the separation angle α is the angle between the connecting line OH and the vertical line OZ when the mineral particles separate from point H of the inner wall.

[0048] When the linear velocity of the ore particle is v and it rises to point H, ; because , , ; Therefore: (1); or: (2); Since π=3.14159, g=9.81 (m / s²) ≈ π² (m / s²); have (rev / min) (3).

[0049] When no DC high voltage is applied and no electricity is applied, the mineral particles are only affected by gravity and centrifugal force. When the conditions of formula (1) are met, the separation angle α marks the position to which the mineral particles have risen when they begin to fall. The higher the speed of the separation drum 2, the smaller the separation angle α, and the higher the position to which the mineral particles rise. When the separation angle α is 0°, the actual speed is equal to the critical speed. The mineral particles have reached the highest point on the inner wall of the separation drum 2 and are about to begin centrifugalization. At this time, cosα = 1. From formula (3), it can be seen that the critical speed of the separation drum 2 is At the same time, it can be seen from formulas (1) and (2) that no matter how the detachment angle α changes, the detachment of the mineral particles is independent of their own mass, that is, it is independent of the size of the mineral particles. The electrostatic separation process is less sensitive to the unevenness of the mineral particle size.

[0050] According to formula (1), and cosα = 1, i.e. when the largest mineral particle passes through the highest point of the inner wall of the separation cylinder 2; have (4); For small-sized ore particles, since they are all close to the inner wall, the distance R' from their center of mass to the center of rotation of the separation drum 2 will be slightly larger than R. When the mass of the small-sized ore particles is m', according to formula (4), ; Due to the need to install related components, the inner diameter of the separation drum 2 is generally around 500mm or larger. The difference between the radius of the largest particle and the radius of the smallest particle of the mineral being separated is too small compared to the inner diameter of the separation drum 2. Taking the separation drum 2 with a radius of 500mm as an example, the centrifugal force increases by 1‰ for every 0.5mm that the radius is smaller than the largest particle. When the radius is 5mm smaller than the largest particle, the centrifugal force increases by 1%. Therefore, when the rotation radius R of the largest particle is used to determine the rotation speed n of the separation drum, the change in the centrifugal force generated by the smallest particle can be ignored. Figure 6 As shown in the A.M. Gaudin curve, when the particle size reaches 2 mm, the gravity will be greater than the electric force (electrostatic induction force f GY ) but will not exceed one order of magnitude, that is, the electric force will not be less than 10% of the gravity. Therefore, it can be predicted that in the inner drum type electrostatic separator of this embodiment, the electrostatic electrode mechanism 4 will generate an attractive force on the conductor and semiconductor particles, that is, the electrostatic induction force f GY For separation of objects with particle sizes of 2mm or larger, it maintains its dominant position even when the centrifugal force changes due to uneven mineral particles. It is particularly effective in separating and recovering valuable metals from irregularly shaped and lamellar waste, replacing eddy current magnetic separators that generate induced eddy currents using an alternating permanent magnetic field.

[0051] Compared with the traditional arc plate and sieve plate electrostatic separators, the inner drum type electrostatic separator of this embodiment selectively separates the mineral particles by utilizing the inner wall of the separation drum 2. The electrostatic induction force f GY As the dominant force in sorting, the electrostatic separation process is less sensitive to the unevenness of mineral particle size, making it possible to sort minerals with coarser particle sizes and prevent coarse-grained conductive mineral particles from mixing into non-conductive mineral particles, resulting in high sorting accuracy. There is no need to classify the mineral particles in advance, and all particle sizes can be directly sorted, simplifying the production process. Moreover, within a certain range, it can replace eddy current magnetic separators for non-ferrous materials, with a large processing capacity and low manufacturing cost.

[0052] Preferably, in this embodiment, the electrostatic electrode mechanism 4 is located directly below the highest point of the inner wall of the separation drum 2. At the highest point of the inner wall of the separation drum 2, the radial component force (mg) of the gravity of the ore particles is J Maximum, can maximize the centrifugal force f LXTo offset the static electrode mechanism 4, it is set just below the highest point of the inner wall of the sorting drum 2, which can maximize the use of the static induction force f GY The ore particles are unloaded, and the unloading effect is better.

[0053] Furthermore, in this embodiment, the sweeping brush assembly 5 includes a brush 51 arranged axially along the sorting drum 2 and a brush driver for rotating the brush 51. The brush 51 rotates in the opposite direction to that of the sorting drum 2. When unloading non-conductive mineral particles, the brush 51 is in close contact with the inner wall of the sorting drum 2. The brush driver (not shown) drives the brush 51 to unload the non-conductive mineral particles. Because the brush 51 rotates in the opposite direction to that of the sorting drum 2, the brush 51 sweeps the non-conductive mineral particles more effectively, and the mineral particles are unloaded more thoroughly.

[0054] Furthermore, in this embodiment, the receiving assembly 6 includes a receiving hopper 61 and a spiral discharger 62 provided at the bottom of the receiving hopper 61. The receiving hopper 61 and the spiral discharger 62 are both arranged axially along the separation drum 2. After the receiving hopper 61 collects the corresponding mineral particles, the spiral discharger 62 discharges the mineral particles in the receiving hopper 61 to the outside of the separation drum 2 for transportation. This structure is simple and reliable.

[0055] Preferably, in this embodiment, the receiving hopper 61 and the spiral discharger 62 are fixed to the machine base 1 through a support frame (not shown in the figure), and the rotation of the separation drum 2 will not interfere with the receiving hopper 61 and the spiral discharger 62; and the receiving hopper 61 and the spiral discharger 62 are adjustably arranged on the support frame, and the receiving hopper 61 and the spiral discharger 62 are adjusted along the horizontal direction perpendicular to the axial direction of the separation drum 2 ( Figure 7 By moving the receiving hopper 61 and the spiral discharger 62 (in the left and right directions), the material receiving position can be adjusted to achieve a better material receiving effect.

[0056] Furthermore, in this embodiment, the feeding mechanism 3 includes a spiral feeder 31 arranged axially along the separation drum 2 and a feeding hopper 32 located at the bottom of the spiral feeder 31. The feeding hopper 32 is provided with a vibrating member 33. The spiral feeder 31 delivers the external ore particles to be separated to the feeding hopper 32. The vibrating member 33 drives the feeding hopper 32 to vibrate back and forth along the axial direction of the separation drum 2, thereby feeding the ore uniformly.

[0057] Preferably, in this embodiment, the discharge port of the feeding hopper 32 is directed toward the descending side of the inner wall of the sorting drum 2 ( Figure 7 In the second quadrant), after being discharged from the discharge port, the mineral particles can move forward under the combined action of gravity and the rotation of the sorting drum 2, preventing the mineral particles from piling up and making the feeding more uniform; and, there is a suitable height between the discharge port of the feed hopper 32 and the lowest point of the inner wall, so that the mineral particles can obtain the initial velocity to generate centrifugal motion to reduce the inertial slip of the mineral particles on the inner wall surface.

[0058] Preferably, in this embodiment, a level meter connected to the motor signal of the spiral feeder 31 is provided at the end of the spiral feeder 31, and the material level at the end of the spiral feeder 31 is detected by the level meter. The PID control instructions in the PLC are used to control the motor frequency of the spiral feeder 31, and the speed of the spiral shaft of the spiral feeder 31 is adjusted in real time to achieve uninterrupted feeding and no blockage along the effective feeding length.

[0059] Furthermore, in this embodiment, a plurality of rotating rollers 11 are provided on the machine base 1, and the sorting drum 2 is mounted on the rotating rollers 11. The outer wall of the sorting drum 2 is provided with roller grooves (not shown) that cooperate with the rotating rollers 11 to axially limit the sorting drum 2. The rotating rollers 11 drive the sorting drum 2 to rotate, allowing the end of the sorting drum 2 to be opened for the entry and exit of mineral particles, resulting in a rational structure. Furthermore, the rotating rollers 11 are disposed in the roller grooves, thereby axially limiting the sorting drum 2, reducing axial displacement of the sorting drum 2 during rotation, and maintaining a stable structure.

[0060] Preferably, in this embodiment, multiple rotating supporting wheels 11 are divided into two groups, and the two groups of rotating supporting wheels 11 respectively support the two sides of the sorting drum 2. One group of rotating supporting wheels 11 is a driving wheel, and the other group of rotating supporting wheels 11 is a driven wheel. The speed of the sorting drum 2 can be controlled by adjusting the speed of the driving wheel, and the structure is simple.

[0061] In this embodiment, the separation drum 2 is a through-hole tubular component with an inner wall serving as the electrostatic separation working surface. The drum's length determines its processing capacity. Both the interior and exterior of the separation drum 2 are machined surfaces. The geometric and positional tolerances, combined with the cumulative error of the rotating support wheel 11, should ensure that the inner wall runout does not exceed 2 mm when the separation drum 2 is operating. This is easily achieved. The separation drum 2 is sized to accommodate high-voltage electrodes, ore feeding, collection, and discharge equipment.

[0062] During the sorting operation, the components of the inner drum electrostatic separator of this embodiment are activated in the following order: starting the separation drum 2 and adjusting it to a predetermined rotational speed → starting the electrostatic electrode mechanism 4 and increasing the voltage to the operating value → starting the spiral discharger 62 below the electrostatic electrode mechanism 4 → starting the spiral discharger 62 below the sweeping brush assembly 5 → starting the brush drive → starting the vibrating element 33 → starting the spiral feeder 31. The shutdown sequence is the opposite of the startup process described above, with a delay between each step to ensure that the ore is fed and the ore particles are discharged.

[0063] During the sorting process, the DC high voltage is adjusted between 40kv and 80kv, and the speed of the sorting drum 2 meets the requirements. , reaching the critical value of centrifugal movement of mineral particles, at this time cosα=1, the separation angle α=0°, after which the speed is no longer adjusted and the sorting effect is better.

[0064] Example 2: Figures 9 to 12The second embodiment of the present invention is shown. The inner drum type electric separator of this embodiment is basically the same as the inner drum type electric separator of the first embodiment, and the differences include: In this embodiment, the separation drum 2 is further provided with a corona electrode mechanism 7 (such as Figure 9 As shown, the sorting drum 2 rotates clockwise, and the corona electrode mechanism 7 is located on the left side of the electrostatic electrode mechanism 4. A corona discharge zone is formed between the corona electrode mechanism 7 and the inner wall of the sorting drum 2, that is, the mineral particles on the inner wall of the sorting drum 2 are first charged by the corona electrode mechanism 7 and then pass through the electrostatic electrode mechanism 4.

[0065] The inner drum type electric separator of this embodiment has a corona electrode and belongs to the type of corona type high voltage electric separator. The corona electrode makes all the mineral particles negatively charged and is suitable for scenes with high requirements for the quality of the conductive mineral particles. Compared with the traditional drum type high voltage electric separator, the inner drum type electric separator of this embodiment selectively separates the mineral particles by using the inner wall of the separation drum 2. Since most or all of the gravity mg of the mineral particles is removed by the centrifugal force f LX cancel out, electric force (mirror force f JX , Coulomb force f KL and electrostatic induction force f GY ) becomes the dominant force in sorting, making it possible to sort minerals with coarser particle sizes, preventing coarse non-conductive mineral particles from mixing into conductive mineral particles, and achieving high sorting accuracy. There is no need to classify the mineral particles in advance, and all particle sizes can be directly sorted, simplifying the production process.

[0066] In this embodiment, the electrostatic electrode mechanism 4 includes a first electrostatic electrode 41 and a second electrostatic electrode 42. A first electrostatic field region is formed between the first electrostatic electrode 41 and the inner wall of the sorting drum 2 to unload the conductor mineral particles. A second electrostatic field region is formed between the second electrostatic electrode 42 and the inner wall of the sorting drum 2 to unload the semiconductor mineral particles. A material receiving component 6 is respectively provided below the first electrostatic electrode 41 and the second electrostatic electrode 42. The first electrostatic electrode 41 is located between the second electrostatic electrode 42 and the corona electrode mechanism 7.

[0067] In order to distinguish between conductor and semiconductor mineral particles, the rotation speed of the separation drum 2 is lowered to a lower value than a critical value, so that the conductor mineral particles can separate from the inner wall of the separation drum 2 at point H before the semiconductor mineral particles. The working process is as follows: the feeding mechanism 3 feeds the material into the separation drum 2, and the mineral particles rotate with the separation drum 2 on the inner wall of the separation drum 2. During the electrostatic separation process, the rotation speed of the separation drum 2 is lower than the critical value for the mineral particles to enter the centrifugal motion state. The mineral particles first pass through the corona discharge area, and the corona electrode mechanism 7 gives all the mineral particles a negative charge. Before the mineral particles that are saturated with charge in the corona discharge area enter point H, the charge carried by the conductor mineral particles has already been released on the surface of the inner wall of the separation drum 2. Through the control of the rotation speed of the separation drum 2, the mineral particles begin to be thrown away from the inner wall at point H corresponding to the separation angle α, and fall on point M on the other side of the inner wall (such as Figure 11As shown), in order to strengthen the shedding process of the conductive mineral particles and at the same time deviate their motion trajectory toward the receiving assembly 6 below the first electrostatic electrode 41, a first electrostatic electrode 41 is provided below point H. Under the action of this electrode, the conductive mineral particles are more likely to detach from the inner wall of the sorting drum 2 and enter the first electrostatic field. Since the electrostatic electrode is negative in polarity, the end of the conductive mineral particles close to the first electrostatic electrode 41 generates a positive charge, while the other end generates a negative charge. As a result, the conductive mineral particles are attracted by the first electrostatic electrode 41, change their motion trajectory, and fall below the first electrostatic electrode 41 (as shown). Figure 11 and Figure 12 As shown, Figure 11 is the movement trajectory of the conductor mineral particles when no electrostatic electrodes are set. Figure 12 The movement trajectory of the conductor mineral particles after the first electrostatic electrode 41 is set).

[0068] Since the discharge time of semiconductor mineral particles (including inclusions or conjoined bodies of conductors and non-conductors) is longer than that of conductor mineral particles, the image force f generated by the residual charge is JX Can compensate for centrifugal force f LX After passing through point H, the semiconductor particles continue to maintain circular motion and arrive near point Z. A second electrostatic electrode 42 is set below point Z. When the semiconductor particles enter the second electrostatic field, the residual charge continues to decrease, and the image force f JX The Coulomb force f KL Also becomes very small, when the two and the centrifugal force f LX The combined force is not enough to counteract the electrostatic induction force f GY Radial force with increasing gravity (mg) J , the semiconductor mineral particles will break away from the inner wall and fall into the receiving assembly 6 below the second electrostatic electrode 42.

[0069] The charge on the non-conductive mineral particles is released slowly. Under the same rotation speed condition as mentioned above, they will be firmly adsorbed on the inner wall of the sorting drum 2 and finally unloaded by the sweeping brush assembly 5 into the material receiving assembly 6 below the sweeping brush assembly 5.

[0070] Furthermore, in this embodiment, the separation angle α, in addition to meeting the requirements of the installation of related components and the space for unloading ore, needs to be limited to its maximum value. Otherwise, if the cosα value (see formula 1) corresponding to the separation angle α is too small, the difference between the gravity and centrifugal force on the ore particles will exceed the range of the electric force, thereby limiting the maximum particle size of the selected ore. Figure 6As shown), when the density of the non-conductor is close to that of quartz and reaches a particle size of 2 mm, the gravity will be greater than the effect of the electric force but will not exceed one order of magnitude, that is, the electric force will not be less than 10% of the gravity. Therefore, the separation angle α must be cosα ≥ 0.9, that is, the centrifugal force offsets 90% of the gravity of the mineral particles. Under this condition, the electric force will still play a dominant role in the behavior of the mineral particles. In addition, due to the strengthening effect of the first electrostatic electrode 41, even if the cosα value exceeds 0.9, within a certain range, the conductive mineral particles can still be effectively unloaded at point H, which will bring more flexibility to the sorting of larger mineral particles (particle size greater than 2 mm). It can be seen from formula (3) that the rotation speed of the separation drum 2 (rev / min), where D is the diameter of the rotation of the largest particle mass center around the center of the separation drum 2. When the value of cosα is limited to 0.9≤cosα≤1, the speed of the separation drum 2 should be Adjust within the range.

[0071] Preferably, in this embodiment, the first electrostatic electrode 41 is located on the line OH. At this time, the centrifugal force f LX Radial force component with gravity (mg) J Equal in size and opposite in direction (e.g. Figure 10 shown), that is, f LX = (mg) J The conductive mineral particles in the state of centrifugal force and gravity balance will be attracted by the first electrostatic electrode 41 and subjected to the electrostatic induction force f GY , it falls off the inner wall and into the receiving assembly 6 below the first electrostatic electrode 41; since the first electrostatic electrode 41 is located on the line connecting point H and the axis of the sorting drum 2, it can maximize the use of the electrostatic induction force f GY The ore particles are unloaded, and the unloading effect is better.

[0072] Furthermore, in this embodiment, the second electrostatic electrode 42 is located just below the highest point of the inner wall of the separation drum 2. When the semiconductor particles pass through the highest point of the inner wall of the separation drum 2, the radial component of the gravity of the semiconductor particles (mg) J Maximum, can maximize the centrifugal force f LX , the gradually decreasing Coulomb force f KL and the mirror force f JX To offset the static electricity, the second electrostatic electrode 42 is set just below the highest point of the inner wall of the sorting drum 2, which can maximize the use of the static electricity induction force f GY The ore particles are unloaded, and the unloading effect is better.

[0073] Furthermore, in this embodiment, both the first and second electrostatic electrodes 41 and 42 are electrostatic tubes, arranged axially along the separation drum 2 and rotatable about their own axes. This rotation of the tubes allows the removal of accumulated mineral particles from the tubes, preventing the resulting electrostatic field distortion caused by accumulated mineral particles, which could affect the separation efficiency. Preferably, in this embodiment, the electrostatic tubes can be rotated to a certain angle periodically or manually through an insulating member using a pneumatic or electric linear motion device (e.g., a cylinder, hydraulic cylinder, or electric arm), resulting in a simple and reliable structure.

[0074] In this embodiment, the electrostatic tube is a metal tube with a diameter of 40mm-70mm, and is slightly longer than the sorting drum 2. It can be at the same potential as the corona electrode mechanism 7 and is fixed to the machine base 1 through insulating materials. The static electrode distance is generally 30mm-100mm, which can be adjusted according to the effect of attracting conductors or semiconductors. The electrostatic tube can also rotate a certain angle around the axis of the sorting drum 2, and has good flexibility.

[0075] Furthermore, in this embodiment, the corona electrode mechanism 7 includes two arc-shaped corona frames 71 arranged at both ends of the sorting tube 2, and a corona wire assembly 72 is provided on the arc-shaped corona frame 71, and each corona wire assembly 72 is at the same distance from the inner wall of the sorting tube 2. The corona wire assembly 72 is connected to the negative pole of the high-voltage DC power supply, and the sorting tube 2 is connected to the positive pole of the high-voltage DC power supply and grounded. A corona discharge zone is formed between the corona electrode mechanism 7 and the inner wall of the sorting tube 2 to charge the mineral to be sorted. The arc-shaped corona frame 71 is used to fix and straighten the corona wire. A protrusion is provided on the arc-shaped corona frame 71. In order to prevent the protrusion from discharging to the inner wall of the sorting tube 2, the two arc-shaped corona frames 71 are installed at appropriate positions outside the two ends of the sorting tube 2 with insulating material; the corona wire assembly 72 is composed of one to several nickel-chromium wires with a diameter of 0.25-0.5mm, which are connected to the rising side of the mineral to be sorted in the sorting tube 2 ( Figure 9 The third and fourth quadrants in the separation drum are arranged along the axis of the separation drum 2 and are parallel to and equidistant from the inner wall of the separation drum 2 to ensure uniform discharge.

[0076] Preferably, in this embodiment, the distance between the arc-shaped corona frame 71 and the inner wall of the sorting drum 2 is adjustable, and the arc-shaped corona frame 71 can rotate around the axis of the sorting drum 2, so as to facilitate adjustment of the area of ​​the corona discharge zone and provide good flexibility. In this embodiment, the corona pole distance is generally 30mm-100mm.

[0077] In this embodiment, the feeding mechanism 3, the electrostatic electrode mechanism 4, the sweeping brush assembly 5 and the corona electrode mechanism 7 are all installed in the sorting drum 2 through the base 1, so as not to interfere with the rotation of the sorting drum 2, and the structure is reasonable.

[0078] In the inner drum electrostatic separator of this embodiment, during the sorting operation, the various components are started in the following order: start the sorting drum 2 and adjust it to a predetermined speed → start the corona electrode mechanism 7, the first electrostatic electrode 41, and the second electrostatic electrode 42 and increase the voltage to the operating value → start the spiral discharger 62 below the first electrostatic electrode 41 → start the spiral discharger 62 below the second electrostatic electrode 42 → start the spiral discharger 62 below the sweeping brush assembly 5 → start the brush drive → start the vibrating element 33 → start the spiral feeder 31. The shutdown sequence is the opposite of the above, with a reasonable delay between each step to ensure that the ore is fed and the ore particles are emptied.

[0079] During the sorting process, the DC high voltage is adjusted between 40kv and 80kv, and the speed of the sorting drum 2 is , and adjusted within the range of cosα=0.9-1 to control the quality of conductor and semiconductor mineral particles.

[0080] The above description is only a preferred embodiment of the present invention and does not constitute any formal limitation to the present invention. Although the present invention has been disclosed as above in terms of a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art can, without departing from the spirit and technical solution of the present invention, use the methods and technical contents disclosed above to make many possible changes and modifications to the technical solution of the present invention, or modify it into an equivalent embodiment of equivalent changes. Therefore, any simple modification, equivalent replacement, equivalent change and modification made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention, still fall within the scope of protection of the technical solution of the present invention.

Claims

1. An inner drum type electric separator, comprising a base (1), characterized in that: A sorting drum (2) is rotatably mounted on the machine base (1), and a feeding mechanism (3), an electrostatic electrode mechanism (4) and a sweeping brush assembly (5) are provided in the sorting drum (2). The feeding mechanism (3) is used to feed materials to the inner wall of the sorting drum (2), and the sweeping brush assembly (5) is located on one side of the electrostatic electrode mechanism (4) along the rotation direction of the sorting drum (2). A material receiving assembly (6) is provided below the electrostatic electrode mechanism (4) and the sweeping brush assembly (5). The electrostatic electrode mechanism (4) is used to unload semiconductor and conductor mineral particles, and the sweeping brush assembly (5) is used to unload non-conductor mineral particles.

2. The inner drum type electric separator according to claim 1, characterized in that: The separation drum (2) is further provided with a corona electrode mechanism (7) located on the side of the electrostatic electrode mechanism (4) opposite to the rotation direction of the separation drum (2), and a corona discharge zone is formed between the corona electrode mechanism (7) and the inner wall of the separation drum (2).

3. The inner drum type electric separator according to claim 2, characterized in that: The electrostatic electrode mechanism (4) comprises a first electrostatic electrode (41) and a second electrostatic electrode (42), wherein a first electrostatic field region is formed between the first electrostatic electrode (41) and the inner wall of the sorting barrel (2) to discharge the conductor mineral particles, and a second electrostatic field region is formed between the second electrostatic electrode (42) and the inner wall of the sorting barrel (2) to discharge the semiconductor mineral particles, and the material receiving assembly (6) is provided below the first electrostatic electrode (41) and the second electrostatic electrode (42), respectively, and the first electrostatic electrode (41) is located between the second electrostatic electrode (42) and the corona electrode mechanism (7).

4. The inner drum type electric separator according to claim 3, characterized in that: The rotation speed of the separation drum (2) is n, which satisfies , where D is the diameter of the rotation of the center of mass of the largest ore particle in a circular motion around the center of the separation cylinder (2).

5. The inner drum type electric separator according to claim 3, characterized in that: The second electrostatic electrode (42) is located directly below the highest point of the inner wall of the sorting drum (2).

6. The inner drum type electric separator according to claim 3, characterized in that: The first electrostatic electrode (41) and the second electrostatic electrode (42) are both electrostatic tubes, which are arranged axially along the sorting drum (2) and can rotate around their own axes.

7. The inner drum type electric separator according to claim 1, characterized in that: The sweeping brush assembly (5) comprises a brush (51) arranged axially along the sorting drum (2) and a brush driving member for driving the brush (51) to rotate. The rotation direction of the brush (51) is opposite to the rotation direction of the sorting drum (2).

8. The inner drum type electric separator according to claim 1, characterized in that: The material receiving assembly (6) comprises a material receiving hopper (61) and a spiral ore discharger (62) arranged at the bottom of the material receiving hopper (61), and the material receiving hopper (61) and the spiral ore discharger (62) are both arranged along the axial direction of the separation drum (2).

9. The inner drum type electric separator according to claim 1, characterized in that: The feeding mechanism (3) comprises a spiral feeder (31) arranged along the axial direction of the sorting drum (2) and a feeding hopper (32) provided at the bottom of the spiral feeder (31); a vibrating member (33) is provided on the feeding hopper (32).

10. The inner drum type electric separator according to any one of claims 1 to 9, characterized in that: A plurality of rotating supporting wheels (11) are provided on the machine base (1), the sorting drum (2) is provided on the rotating supporting wheels (11), and the outer wall of the sorting drum (2) is provided with supporting wheel grooves that cooperate with the rotating supporting wheels (11) to limit the axial position of the sorting drum (2).

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