Elutriation system for efficient washing and separation of iron ore and control method of elutriation system

Abstract

The invention belongs to the technical field of mine ore washing equipment, and relates to improvement of the production efficiency of an elutriation machine, in particular to an elutriation system for efficient iron ore washing and separation and a control method thereof.The elutriation system comprises a concentrate pulp mixer, an overflow groove, an elutriation barrel, a supporting platform, an ore washing water path and a control system; the concentrate pulp mixer is arranged above the elutriation barrel, the overflow groove is formed in the lower portion outside the concentrate pulp mixer and is in an inclined table shape, the tailing outlet is formed in the bottom of the inclined table, the middle of the interior of the overflow groove is connected with the elutriation barrel, a middle barrel body of the elutriation barrel is divided into an inner barrel body and an outer barrel body, and multiple sets of magnet exciting coils are arranged between the inner barrel body and the outer barrel body. The lower part of the inner cylinder is connected with an inverted-cone cylinder; a stirring impeller is arranged below the concentrate pulp mixer; the lower part of the elutriation barrel is filled with direct-flow water and rotational flow water through an ore washing water path; the system automatically recognizes working condition changes according to the ore feeding property, the material amount, field data and database set values, the optimal operation mode is selected, a magnetic field, an ore removal valve, a water supply valve and the like are controlled, efficient and intelligent separation of iron ore powder is achieved, and the optimal ore washing effect is achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of mine washing equipment and relates to improving the production efficiency of an elutriator, in particular to an elutriation system for efficient washing of iron ore and a control method thereof. Background Art

[0002] The panning machine is the main washing equipment after grinding and magnetic separation in the production of iron ore powder in mining enterprises. It is used for the final washing process of iron ore production, returning unqualified iron ore powder products to the ball mill for re-grinding, and transporting the qualified particle size iron ore powder to the next process for pellet roasting.

[0003] In the past, dewatering tanks and conventional magnetic separation columns were mainly used for ore washing and beneficiation. The dewatering tank is the equipment for washing iron ore after grinding, and is the gatekeeper equipment for pellet filtration. However, the original dewatering tanks often have low washing efficiency during the production process. Magnetic minerals are prone to magnetic agglomeration and magnetic chains gather into clusters, which are easy to clog pipes and valves, causing the original ball mill to have a large circulating load, uneven force, motor burnout, low grinding efficiency, high water consumption and other problems, and even resulting in high grinding costs, difficult operation and complex processes. The conventional magnetic separation column has low washing efficiency, and the blockage caused by the aggregation and deposition of magnetic clusters affects the washing effect. A coil is installed in the slurry separation cylinder. The conventional design has no outer cylinder, and the coil is directly installed in the inner cylinder, which causes the magnetic field to contact with the slurry for a long time, causing damage to the water inlet and grounding of the coil. In particular, the overflow of the conventional magnetic separation column will carry the qualified iron ore powder product back to the ball mill for re-grinding, which will inevitably cause the iron ore powder to be over-grinded and the ore to become slimy; magnetic minerals are prone to magnetic agglomeration and magnetic chain aggregation, which are easy to clog pipes and valves. The slurry contains a large amount of suspended magnetic matter, which is easy to deposit and aggregate in the magnetic separation column, causing blockage, affecting the ore washing effect, and even causing equipment damage; in addition, the underflow of the iron ore concentrate outlet transports the unqualified particle size iron ore powder to the next process for pellet roasting, which will inevitably cause the pellet quality to substandard and the ore recovery rate to decrease, which has seriously affected the iron ore powder production efficiency, increased the circulation load of the ball mill and reduced the washing efficiency, and brought great difficulties to equipment management and production organization. Summary of the Invention

[0004] The purpose of the present invention is to provide a washing system for efficient iron ore washing, which can maximize the iron ore washing efficiency, reduce the ore mudification rate, reduce the amount of returned sand from the washing tailings, reduce the labor intensity of workers, and reduce production costs; at the same time, it solves the problems of low ore washing efficiency in traditional dewatering troughs, easy occurrence of magnetic agglomeration and magnetic chain aggregation, easy clogging of pipes and valves affecting the ore washing effect, mixed product particles, poor ore discharge, uneven load, large amount of returned sand resulting in large grinding cycle load, ore mudification and high water consumption.

[0005] The technical solution adopted by the present invention to achieve the above-mentioned purpose is: A washing system for efficient iron ore washing, comprising: a concentrate slurry mixer, an overflow trough, an elutriation cylinder, a supporting platform, an ore washing waterway and a control system. The concentrate slurry mixer is arranged above the elutriation cylinder. The concentrate slurry mixer is in the shape of a cylindrical funnel, with tangential feed ports arranged around the upper part, a cylindrical middle part, and a frustum inverted funnel-shaped ore outlet at the lower part. There are ore outlet holes processed around the ore outlet. An overflow trough is arranged at the lower part of the outer surface of the concentrate slurry mixer, which is in the shape of an inclined platform. The tailings outlet is set at the bottom of the platform, and the middle of the overflow tank is connected to the washing cylinder. The washing cylinder is made of stainless steel, with a frustum-shaped upper part and a cylindrical middle part. The middle cylinder is divided into an inner cylinder and an outer cylinder. Multiple sets of excitation coils are set between the inner cylinder and the outer cylinder to isolate the excitation coils from the slurry and water. The inner cylinder and the outer cylinder are connected by an upper flange and a lower flange. A waterproof cover is set at the upper flange, and a supporting platform is set at the lower flange. An inverted cone cylinder is set at the lower part of the lower flange, and the inverted cone cylinder is connected to the inner cylinder; the concentrate ore A stirring impeller is provided below the slurry mixer, and assembly flanges are provided above and below the middle main shaft of the stirring impeller, which are fixedly connected to the wall of the inner cylinder through round steel; the lower part of the washing cylinder is filled with ore-dressing water through the ore-washing water channel; a vortex water pipe is provided at the lower part of the main pipe of the ore-washing water channel, and the vortex water pipe supplies water along the tangent spiral direction of the inverted cone cylinder; a direct current water pipe is provided at the upper part of the main pipe of the ore-washing water channel, and the direct current water pipe is supplied to the ore-washing port at the lower center of the cylinder, and the ore-washing port is a structure in which the lower cylinder is connected to the upper inverted table; the control system includes a PLC controller, sensors, an excitation power supply module, a water supply control module and a concentrate outlet control valve. The sensors include an overflow concentration sensor arranged in the overflow trough, a middle concentration sensor arranged in the middle of the cylinder, an underflow concentration sensor and an underflow pressure sensor arranged at the bottom of the cylinder; the excitation power supply module is used to generate different currents to excite the excitation coil to generate a magnetic field; the water supply control module includes a flow meter, a vortex water valve, a direct current water valve, and an anti-blocking flushing regulating water supply valve.

[0006] Furthermore, the number of the tangential feeding ports is 2-4 groups; the diameter of the ore outlet holes is 5-25 mm, and the spacing is 50-100 mm.

[0007] Furthermore, the overflow trough and the washing cylinder are connected by continuous welding.

[0008] Furthermore, the inner surface of the inner cylinder is pasted with a wear-resistant rubber plate with a thickness of 2-4 mm; the outer surface of the outer cylinder is coated with a polysulfide epoxy resin protective coating.

[0009] Furthermore, an anti-blocking flushing and regulating water supply valve is provided at the lower part of the inverted cone cylinder, and the anti-blocking flushing and regulating water supply valve is an electric regulating butterfly valve.

[0010] Furthermore, the multiple groups of excitation coils include a constant controlled tail magnetic field coil at the top, a circulating magnetic field coil in the middle and a constant compensation magnetic field coil at the bottom, which achieve fast instantaneous current switching through the excitation power supply module to generate different currents, and then generate millisecond-level high-frequency pulse vibration magnetic fields according to the different currents, thereby generating different magnetic fields; each group of excitation coils uses high-strength thermal conductive silicone to protect the excitation coil, and each group of excitation coils is also provided with a group of temperature transmitters.

[0011] A control method for an elutriation system for efficient iron ore washing comprises the following steps: S1. The iron ore slurry is fed into the concentrate slurry mixer tangentially from the tangential feeding port, and the iron ore slurry swirls along the outlet hole at the bottom of the concentrate slurry mixer and enters the washing cylinder; S2, the PLC controller generates different excitation currents through the excitation power supply module according to the different properties of the ore source, and generates different pulse vibration magnetic fields through multiple sets of excitation coils, forming a constant tail control magnetic field area, a circulating magnetic field area and a constant compensation magnetic field area, so that the iron ore slurry in the washing cylinder is dispersed and agglomerated multiple times, and moves downward; S3. Adjust the pressure of the washing water of the direct current valve and the swirl valve according to the properties, particle size, density and concentration of the ore to ensure the washing effect and all the gangue is floated and washed away; S4. Adjust the opening of the anti-blocking flushing and water supply valve according to the ore properties, particle size, density and concentration to ensure the stable operation of the equipment water supply system; S5. Based on the real-time monitoring data from the overflow concentration sensor, middle concentration sensor, underflow concentration sensor, underflow pressure sensor, and flow meter, combined with the database setting values, identify changes in operating conditions, select the optimal operating mode, accurately determine the feed properties, material quantity, and water pressure fluctuations, and control the excitation power supply module, concentrate outlet control valve, DC water valve, and swirl water valve through the PLC controller to adjust the magnetic field parameters, valve opening, and water volume.

[0012] Furthermore, in the S2 process, the iron ore slurry swirls into the washing cylinder and rotates to impact the stirring impeller. The stirring impeller rotates under the impact of the iron ore slurry, continuously interrupting the magnetic agglomeration of the iron ore slurry, the length of the magnetic chain, and increasing the number of magnetic reversals of the minerals, separating the gangue minerals contained in the magnetic chain. At the same time, the guiding effect of the stirring impeller increases the rotation of the iron ore slurry and increases the slurry washing time.

[0013] Furthermore, the constant tail magnetic field area is formed by the top constant tail magnetic field coil, and the two groups of excitation coils are excited in turn according to the set time, and constant and alternating magnetic fields are generated according to different time settings to control tailing and reduce the magnetic iron grade in the tailings; the circulating magnetic field area is formed by the middle circulating magnetic field coil. When working, the two adjacent groups of excitation coils are alternately powered according to the set time to form circulating excitation, generate a circulating separation magnetic field, control the length of the magnetic chain, the size of the magnetic agglomeration and the downward speed of the magnetic chain, change the time the mineral stays in the washing cylinder, and control the quality of the iron concentrate. The constant compensation magnetic field zone is formed by the constant compensation magnetic field coil, which generates a background magnetic field to prevent magnetic agglomeration of magnetic flux and the formation of central magnetic voids, ensuring that the minerals are evenly distributed at the bottom of the washing cylinder; the temperature transmitter on each set of excitation coils monitors the working temperature of the excitation coils. When the temperature of the excitation coil exceeds the preset temperature of 70°C, an alarm is issued and fault cooling processing is performed, that is, the washing system automatically increases the direct current cooling water flow rate to reduce the temperature of the excitation coil; when the temperature exceeds the preset temperature of 110°C, the washing system automatically stops the power supply to the set of excitation coils.

[0014] Furthermore, overflow, midstream, and underflow concentration sensors are used to directly measure the magnetic content in the iron ore slurry. This data is transmitted to the control system's PLC controller, which adjusts the magnetic field strength based on the amount of magnetic material in the overflow and iron ore concentrate products, minimizing magnetic material loss in the overflow. The overflow and underflow concentration sensors are inductive oscillation sensors, each containing a winding coil. When magnetic material in the iron ore slurry passes through the winding coil, it alters the magnetic induction current in the coil.

[0015] Furthermore, the PLC controller adopts an adaptive intelligent PLC control system, with an optional remote communication module. Through upper computer management, it can realize remote centralized control of the control room, remote start and stop, remote monitoring and setting of operating parameters, and remote fault monitoring and self-diagnosis.

[0016] The beneficial effects of this invention are as follows: This system, tailored to the requirements of magnetic iron ore separation, employs an electromagnetic field within the elutriation cylinder. This system combines gravity, buoyancy, magnetic attraction, magnetic repulsion, and magnetic vibration to create and utilize magnetic agglomeration and magnetic chains during the magnetite separation process, while completely destroying these agglomerations and chains, thereby improving the grade of magnetic ore. The magnetic and gravity separation principle enables fluidized separation of solid-liquid two-phase mixtures in a magnetic field. The use of intelligent control algorithms significantly increases the number of magnetic tumbling of minerals to 500 times per minute under the action of pulsed constant magnetic fields and circulating magnetic fields, overcoming the drawbacks of incomplete separation caused by the single permanent magnetic field and the absence of pulsed vibrating magnetic fields used in traditional dewatering trough ore washing. It also overcomes the drawbacks of conventional magnetic separation column equipment, which uses a voltage regulating module to adjust the magnetic field size and has a low number of magnetic tumbling times. The system achieves agglomeration of electromagnetic iron powder when the magnet is turned on, and descends by gravity when the power is off. There is no pulsed vibrating magnetic field when the power is on, so that the gangue and lean conglomerates are fully separated from the iron concentrate. Water is added to increase the rising water flow rate, accelerating the ascent of gangue minerals, allowing them to leave the magnetic field zone and be discharged as tailings. At the same time, the magnetic material descends for further purification.

[0017] This system uses rotating impellers and pulsed electromagnetic field technology to interrupt magnetic cluster aggregation and increase magnetic chain tumbling, thereby improving ore washing efficiency, reducing the circulating load of the grinding system, and reducing the energy consumption of the ball mill and the ore muddiness rate. This system monitors changes in the magnetic content of the overflow tailings through an overflow concentration sensor, automatically adjusts the magnetic field and water supply pressure, and selectively removes conjoined bodies according to grade, achieving efficient and intelligent separation of iron ore concentrate. It not only has a high degree of automation, large processing capacity, and excellent technical performance indicators, but is also particularly beneficial for lean magnetite. After adopting the washing system of the present invention, the washing return efficiency, ore washing efficiency, ore washing output, and post-washing grade are significantly improved, and the incidence of system failures is significantly reduced. The washing system of the present invention uses multiple sets of excitation coils set between the inner and outer cylinders to isolate the slurry, water, and excitation coils from contact, eliminating water ingress and grounding damage to the excitation coils. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a structural schematic diagram of the washing system for efficient washing of iron ore of the present invention; Figure 1: Concentrate slurry mixer; 1-1: Tangential feed port; 1-2: Ore outlet; 2: Overflow chute; 2-1: Tailings outlet; 3: Washing cylinder; 3-1: Inner cylinder; 3-2: Outer cylinder; 3-3: Waterproof cover; 3-4: Inverted cone cylinder; 3-5: Concentrate outlet; 4: Support platform; 5: Washing waterway; 5-1: Cyclone pipe; 5-2: Direct current pipe; 6: Control system; 6-1: Overflow concentration sensor; 6-2: , middle concentration sensor; 6-3, bottom flow concentration sensor; 6-4, bottom flow pressure sensor; 6-5, flow meter; 6-6, swirl water valve; 6-7, direct current water valve; 6-8, anti-blocking flushing and regulating water supply valve; 6-9, concentrate outlet control valve; 7, excitation coil; 7-1, constant tail magnetic field coil; 7-2, circulating magnetic field coil; 7-3, constant compensation magnetic field coil; 7-4, temperature transmitter; 8, stirring impeller. DETAILED DESCRIPTION

[0019] The present invention will be further described below with reference to the embodiments and accompanying drawings: A washing system for efficient washing of iron ore, such as Figure 1 Shown, including: Concentrate slurry mixer 1, overflow tank 2, washing cylinder 3, support platform 4, washing water channel 5 and control system 6, The concentrate slurry mixer 1 is arranged above the washing cylinder 3, and an overflow trough 2 is arranged on the lower part of the outside of the concentrate slurry mixer 1. The function of the overflow trough 2 is to collect tailings and gangue. The washing cylinder 3 includes an inner cylinder 3-1 and an outer cylinder 3-2. Multiple groups of excitation coils 7 are arranged between the inner cylinder 3-1 and the outer cylinder 3-2, and the middle of the inner cylinder 3-1 and the outer cylinder 3-2 are completely isolated from the slurry or water, which separates the slurry, water and the excitation coil from contact, and prevents the excitation coil from being damaged by water ingress and grounding; the support platform 4 supports the concentrate slurry mixer 1, the overflow trough 2 and the washing cylinder 3 and maintains them in a stable working state. The washing waterway 5 includes a straight The flow water path and the swirl water path send the washing water into the washing cylinder 3. The control system 6 includes sensors, an excitation power supply module, a water supply control module and a concentrate outlet control valve. The sensors include an overflow concentration sensor 6-1 arranged in the overflow trough, a middle concentration sensor 6-2 arranged in the middle of the washing cylinder 3, and an underflow concentration sensor 6-3 and an underflow pressure sensor 6-4 arranged at the bottom of the washing cylinder 3; the excitation power supply module is used to generate different currents to excite the excitation coil to generate a magnetic field; the water supply control module includes a flow meter 6-5, a swirl water valve 6-6, a direct current water valve 6-7 and an anti-blocking flushing regulating water supply valve 6-8.

[0020] The concentrate slurry mixer 1 is in the shape of a cylindrical funnel and is made of 304 stainless steel with a thickness of 6-10mm. Tangential feeding ports 1-1 are arranged around the upper part of the concentrate slurry mixer 1, the middle part is cylindrical, and a truncated cone inverted funnel-shaped ore outlet 1-2 is arranged at the lower part. The diameter of the tangential feeding port 1-1 is 100-200mm, and the number is 2 to 4 groups. Tangential feeding is conducive to magnetic agglomeration, magnetic chain opening and iron concentrate dispersion, solving the (conventional) traditional vertical downward feeding problem of iron concentrate blockage, magnetic agglomeration and magnetic chain aggregation and dispersion; ore outlet 1-2 is processed around the ore outlet, the diameter of the ore outlet is 5-25mm, and the spacing is 50-100mm; this setting is also conducive to avoiding the problems of iron concentrate blockage, magnetic agglomeration, magnetic chain opening and iron concentrate dispersion during traditional feeding from the center of the feeding cylinder, thereby improving ore washing efficiency.

[0021] The lower outer part of the concentrate slurry mixer 1 is symmetrically welded with oblique steel plates, which makes it easy to place the concentrate slurry mixer 1 in the upper circular groove of the overflow trough 2. The overflow trough 2 is in the shape of an oblique table, and a tailings outlet 2-1 is provided at the bottom of the oblique table. The middle of the interior of the overflow trough 2 is connected to the washing cylinder 3. The overflow trough 2 and the washing cylinder 3 are both made of stainless steel 304. They are connected by continuous welding, and the welding height is greater than 10 mm.

[0022] The upper cylinder of the washing cylinder 3 is a large cylinder with a thickness of 6-10mm, and the middle cylinder is a small cylinder. The design between the upper cylinder and the middle cylinder is a truncated cone. The middle cylinder is divided into an inner cylinder 3-1 and an outer cylinder 3-2. The thickness of the inner cylinder 3-1 is 5-7mm, and the thickness of the outer cylinder 3-2 is 6-10mm. The inner cylinder 3-1 is thinner than the outer cylinder 3-2, which is conducive to better magnetic permeability. The inner cylinder 3-1 and the outer cylinder 3-2 are connected by an upper flange and a lower flange. The flange material is Q235, and a waterproof cover 3- is provided at the upper flange. 3. Prevent water and slurry from entering the excitation coil. A support platform 4 is installed at the lower flange. Support platform 4 is composed of four steel pipe columns welded together continuously, with a weld height greater than 10mm. The washing cylinder 3 is fixed to support platform 4. An inverted cone 3-4 is installed below the lower flange. The inverted cone 3-4 is connected to the inner cylinder 3-1 through continuous welding, with a weld height greater than 10mm. To increase the service life of the washing cylinder 3 and reduce wear, a wear-resistant rubber sheet with a thickness of 2-4mm is attached to the inside of the inner cylinder 3-1. The outer surface of the outer cylinder 3-2 is coated with a polysulfide epoxy resin protective coating to provide corrosion protection. The polysulfide epoxy resin protective coating on the outer surface has self-leveling properties.

[0023] The excitation coil 7 includes a top constant tail magnetic field coil 7-1, the number of coils is 2 to 4 groups, the cross-sectional shape is rectangular, the single-strand coil is made of flat aluminum wire or flat copper wire, the size is 50×5mm, and the power is alternately circulated and excited in turn according to the set time to generate a constant and alternating magnetic field, which is mainly used to control the amount of overflow tailings, so as to achieve the effect of reducing the magnetic iron grade in the tailings and improve the washing efficiency; the middle circulating magnetic field coil 7-2, the number of coils is 7 to 16 groups, the cross-sectional shape is rectangular, the single-strand coil is made of flat aluminum wire or flat copper wire, the size is 50×5mm, and when working, two adjacent excitation coils are alternately powered and cyclically excited according to the set time to generate a circulating ore washing magnetic field, which mainly controls the length of the magnetic chain and the downward speed of the magnetic chain, and changes the residence time of the mineral inside the cylinder. time, the purpose is to control the grade of iron ore concentrate and improve the quality of iron ore concentrate; the constant compensation magnetic field coil 7-3 at the bottom, the number of coils is 2 to 4 groups, the cross-section shape is rectangular, the single-strand coil is made of flat aluminum wire or flat copper wire, the size is 50×5mm, and the power supply is alternately circulated to prevent magnetic agglomeration of the magnetic chain and the formation of central magnetic voids, thereby ensuring that the minerals are evenly distributed inside the cylinder, improving the ore washing efficiency and ensuring the grade of the iron ore concentrate; each group of excitation coils is protected by high-strength thermal conductive silicone rubber, and a group of temperature transmitters 7-4 are set at the same time. When the temperature exceeds the preset temperature of 70℃, an alarm is issued and a fault cooling process is performed, that is, the washing system automatically increases the DC cooling water flow, thereby reducing the temperature of the excitation coil; when the temperature exceeds the preset temperature of 110℃, the washing system automatically stops the power supply to the group of excitation coils.

[0024] The constant tail magnetic field coil 7-1, the circulating magnetic field coil 7-2, and the constant compensation magnetic field coil 7-3 achieve fast instantaneous current switching through the excitation power supply module, generating different currents, and then generating millisecond-level high-frequency pulse vibration magnetic fields according to the different currents, thereby generating different magnetic fields.

[0025] In order to achieve the best washing effect, the washing system uses sensors of different properties according to the properties, particle size, density and concentration of the ore pulp. According to different detection results, the PLC program is used to control different excitation currents, and correspondingly generate different magnetic field strengths (the automatic adjustment range of the magnetic field strength is 70~150KA / m). It intelligently senses different ore pulp properties and obtains the best washing effect.

[0026] The lower part of the washing cylinder 3 is filled with ore washing water through the ore washing water channel 5; the diameter of the main pipe of the ore washing water channel 5 is 100-150mm, and a flow meter is installed in the middle. The pressure is 0.25-0.35MPa and the water consumption is 80-120m3 / h. The lower part of the main pipe of the ore washing water channel is provided with a swirl water pipe 5-1. The swirl water pipe 5-1 supplies water in a spiral direction along the tangent line of the inverted cone cylinder. The diameter of the swirl water pipe 5-1 is set to 60-100mm and the pressure is set to 0. 20~0.30MPa; a direct current water pipe 5-2 is set on the upper part of the main pipe of the ore washing water channel 5. The direct current water pipe 5-2 has a diameter of 80~120mm and a pressure of 0.25~0.35MPa. It is fed into the ore washing port at the lower center of the cylinder. The ore washing port is a structure in which the lower cylinder is connected to the upper inverted truncated cone. The water pressure of the ore washing port can be automatically adjusted according to the properties, particle size, density and concentration of the ore to ensure its ore washing effect and the complete floating and washing of gangue; A concentrate outlet control valve 6-9 and an anti-blocking flushing regulating water supply valve 6-8 are arranged at the lower part of the inverted cone 3-4. The concentrate outlet control valve 6-9 controls the flow rate of the concentrate outlet 3-5 after washing. The anti-blocking flushing regulating water supply valve 6-8 is an electric regulating butterfly valve with a diameter of 60 to 100 mm and a pressure of 0.50 to 0.70 MPa. The flushing pressure can be automatically adjusted according to the properties, particle size, density and concentration of the ore, while improving the service life of the electric regulating water valve. The process is reliable and the performance is stable, which can ensure the stable operation of the equipment water supply system.

[0027] The main equipment and flow parts of the washing system are made of 304 wear-resistant stainless steel. They are compacted with professional equipment and tooling and welded with argon arc welding. After welding, the density of the weld is inspected with a flaw detector. After the sealing welding of the washing cylinder, a 72-hour pressure maintenance test is carried out to ensure that the cylinder has no defects. The inner cylinder 3-1 and the outer cylinder 3-2 are subjected to a water filling test before use to ensure that there will be no water leakage during the operation of the system, effectively preventing the excitation coil from entering the slurry and the water insulation grounding from being damaged.

[0028] The excitation coil 7 requires high insulation, high strength, high moisture resistance, and corrosion resistance. Based on production experience and model software calculations, the current and temperature tolerance parameters of the excitation coil are designed to achieve the required magnetic field effect and service life, overcoming the problems of traditional excitation coils with low load power, high heat generation, and short service life. To ensure the excitation coil's moisture resistance, corrosion resistance, insulation, mechanical strength, heat dissipation, and delayed aging, the excitation coil is insulated with high-strength silicone rubber, with an insulation grade of H and a protection level of IP67. After undergoing moisture resistance, corrosion resistance, and insulation treatment, the excitation coil undergoes a 1200V / 50Hz AC withstand voltage test, with no breakdown or flashover within one minute. Each coil is equipped with an internal temperature transmitter that can monitor the temperature of each coil online. If the temperature exceeds the set range, automatic alarms, power outages, and shutdowns will be implemented.

[0029] To facilitate the maintenance of the excitation coil and prevent slurry and water from entering the excitation coil and reducing its insulation performance, the excitation coil is arranged between the inner cylinder and the outer cylinder. A waterproof cover is set on the upper part of the outer cylinder to prevent water and slurry from entering the excitation coil. Heat dissipation space is reserved between the excitation coil and the outer cylinder, and a dehumidification function is configured inside to facilitate natural heat dissipation of the excitation coil.

[0030] In order to increase the service life of DC water valves, swirl water valves, and anti-blocking flushing and regulating water supply valves, the anti-blocking flushing and regulating water supply valves use electric butterfly valves, which have reliable technology and stable performance, and can ensure stable water supply to the system; DC water valves and swirl water valves use highly wear-resistant material Nainate rubber valve core electric hose valves, which have simple structure and are easy to replace, while also increasing the service life of the valve core.

[0031] The control system's electric control cabinet is waterproof and dustproof with a protection level of IP55 or above. A voltage stabilizer distribution box is added to improve the reliability of the equipment's power supply and protect the electric control cabinet from the impact of high voltage and high current on site to maintain safe and reliable operation. The internal low-voltage electrical components are Schneider products, the PLC and touch screen are Siemens products, and the thyristor rectifier component chips are also well-known brands. An isolation transformer is used in conjunction with the thyristor rectification mode to isolate the impact of the grid power supply's peak (interference) pulse on the rectifier module. The control system uses low-voltage power supply to prevent direct impact on the equipment when the external power grid changes, avoid the risk and injury of high-voltage electric shock in a humid environment, and ensure the safety of operators on the job.

[0032] All instruments and meters are high-precision, well-known brands, ensuring stable system performance and high monitoring accuracy, and ensuring the reliability and stability of the washing system. Instruments, meters, and control circuits are equipped with lightning protection and electromagnetic interference protection measures.

[0033] The temperature transmitter is intelligent and has an adjustable range. The input signal is RTD, thermocouple or mV signal, the output signal is 4-20mADC, the power supply is 24VDC, and the input and output power supply are three-terminal isolated.

[0034] The bottom flow pressure sensor is a two-wire, intelligent type with an accuracy better than 0.1% and a range of 0 to 150 kPa. It is equipped with a diaphragm seal and two valve groups made of 316 stainless steel. It is equipped with a display head and buttons, and has a protection level of IP67.

[0035] The flow meter adopts electromagnetic flow meter, which is used to monitor the water supply of the washing system and is installed in the water supply pipeline. The electromagnetic flow meter adopts intelligent type and has Modbus, ModBus RTU or Ethernet communication function. The electromagnetic flow meter is suitable for applications where the medium velocity is greater than 0.5m / s and the medium conductivity is greater than 20μs / cm.

[0036] The adaptive intelligent PLC control system is an unmanned management control system that uses high-performance control components to improve the stability and reliability of the control system. The PLC controller uses a Siemens programmable controller, is equipped with a memory card, and has Ethernet communication function. The system has an Ethernet communication interface and supports TCP / IP protocol. It uses upper and lower software, databases, etc. to be compatible with the main control system to form a fully automatic pulse-type adaptive intelligent perception PLC program control washing system to achieve unattended operation of the system. The sensors, flow meters, and electric control valves in the system are all controlled by the PLC controller using an adaptive intelligent PLC control program. It has two operating modes: single-unit start / stop and one-button automatic operation, as well as various protection functions; the communication interface is an independent Ethernet interface. A dedicated address storage area is planned for the DCS system integration requirements, providing an address table and detailed description, PLC control logic diagram, and unencrypted PLC and human-machine interface control program. It can communicate with the central control DCS system and can realize monitoring, control, and emergency stop functions on the main PLC control system of the centralized control center.

[0037] The adaptive intelligent PLC control system of the washing system can also realize real-time data transmission with the enterprise's full-process pipeline system, and realize remote monitoring, control and emergency stop of the washing system in the centralized control center. Multiple washing systems are managed by the host computer to realize remote centralized control of the control room, with one-button start / stop function, remote communication with the host computer, remote start / stop, remote monitoring and setting of washing system operating parameters and remote fault monitoring, with a higher degree of unmanned intelligence.

[0038] The specific monitoring and control scope of the adaptive intelligent PLC control system of the washing system includes: adjustment and control of the electromagnetic field intensity according to the fluctuation of ore properties, real-time monitoring and control of underflow concentration signal, real-time monitoring and control of overflow concentration signal, real-time monitoring and control of rising water signal, rising water flow monitoring, middle concentration control and signal detection, DC water valve opening control, swirl water valve opening control, real-time monitoring and control of excitation coil working current, real-time monitoring of excitation coil temperature, and real-time monitoring and control of concentrate outlet valve opening.

[0039] The elutriation system's adaptive intelligent PLC control system offers four control modes: central automatic (remote automatic), central manual (remote manual), on-site automatic, and on-site manual. Remote automatic: Upon receiving remote start / stop commands, the elutriation system automatically initiates and stops in a chained manner, adjusting each process step to ensure optimal operation. The human-machine interface monitors all operating and machine data, enabling one-click automatic operation, allowing unattended operation of the elutriation machine on-site. Remote manual: Remotely start / stop and control each elutriation system individually via the human-machine interface. On-site automatic: Chain start / stop and control each process step automatically via the on-site touch screen to ensure optimal operation. The human-machine interface monitors all operating and machine data, enabling one-click automatic operation. On-site manual: Individual elutriations can be started and stopped in a chained manner via the on-site touch screen, automatically adjusting each process step to ensure optimal operation. The human-machine interface monitors all operating and machine data, enabling one-click automatic operation. On-site manual: Individual elutriations can be started and stopped in a chained manner via the on-site touch screen. For on-site inspection and maintenance, the system can be started and stopped directly.

[0040] The elutriation system's adaptive intelligent PLC control system features alarms and interlocks, providing real-time, quantifiable data for predictive maintenance and health management. The system's alarms and interlocks are comprehensive and timely, with alarms and interlocks configured for each parameter. The elutriation system features continuous self-monitoring, instantly addressing any anomalies and providing alerts on the centralized control system's operation screen. These include low water pressure and water volume alarms; rising water flow alarms: alarms for abnormal signals from the electric control valve and electromagnetic flowmeter; overflow system alarms: alarms for excessive tail volume monitored by the overflow system and abnormal overflow sensor signals; electromagnetic coil system alarms: alarms for abnormal operating conditions of the coil power supply module, temperature sensor, and coil. Coil operating current overload alarms and coil temperature alarms: If the coil temperature exceeds the set range (70°C to 110°C), the system automatically corrects the fault and independently controls the temperature-sensitive coil. The underflow discharge system alarm: If the underflow electric control valve becomes clogged, the valve opening is automatically adjusted, cone backwash is initiated, and an alarm is issued. The system provides real-time quantifiable data self-checking functions for predictive maintenance and health management of the washing system, and monitors changes in various parameters of the washing system, the working hours and working conditions of all instruments, meters, and electronically controlled valves in real time. The central control room can promptly query the operating conditions and usage of all electrical appliances in the washing system on site, facilitating regular inspections by on-site operators. At the same time, the system will regularly pop up the month-end inspection and maintenance status table for each cycle (calculated on a monthly basis, at the end of each month), facilitating regular inspections and predictive maintenance plans by on-site maintenance personnel, thereby achieving equipment health management.

[0041] The elutriation system's adaptive intelligent PLC control system and central control DCS system provide real-time display of operating data such as the system's operating current, underflow valve position, rising water flow, coil temperature, and magnetic field strength. They also automatically monitor, adjust, compensate, issue alarms, store data, and analyze and query process parameters such as underflow concentration and overflow concentration. The elutriation system's adaptive intelligent PLC control system provides a corresponding solution for every change in on-site operating conditions. Based on feedback from the on-site elutriation system's operating status and operating data, it comprehensively predicts feed properties, ore volume changes, and iron ore concentrate product specifications. It then automatically adjusts elutriation system settings and adjusts magnetic field strength, water supply, and discharge speed to maintain stable and efficient equipment operation.

[0042] The elutriation system uses an overflow concentration sensor that can directly measure the magnetic content in the iron ore slurry. It is used to monitor the magnetic content of the tailings in the elutriation system. The middle concentration sensor, underflow concentration sensor, and underflow pressure sensor are used in the elutriation cylinder to monitor the concentration and pressure in the elutriation cylinder. The monitoring accuracy is higher, the elutriation system is more sensitive, and the sorting control accuracy is higher, making the monitoring function of the elutriation system more advanced and reasonable, the performance reliable, and adaptable to various working conditions.

[0043] The overflow concentration sensor uses a concentration inductive oscillation sensor. There is a winding coil inside the probe. When magnetic objects pass through the coil, the coil inductance will change. The inductive oscillation sensor is particularly sensitive to iron in the overflow. According to the content of magnetic objects in the iron ore slurry in the overflow, the magnetic field strength in the washing system is adaptively controlled intelligently to reduce the loss of iron in the overflow, achieve low tailings and smooth operation.

[0044] The magnetic field strength automatically adjusts the excitation current based on fluctuations in ore properties to achieve the desired magnetic field intensity. The elutriation system uses two monitoring methods to continuously monitor changes in the incoming ore load. As the ore load increases, the specific gravity of the iron ore slurry increases, the pressure monitored by the underflow pressure sensor increases, and the iron equivalent of the overflow sensor increases. The system automatically increases the electromagnetic field strength, strengthening the downward magnetic attraction to the magnetic minerals and adjusting the overflow and underflow concentrations. As the ore load decreases, the specific gravity of the iron ore slurry decreases, and the system automatically decreases the electromagnetic field strength to reduce the downward attraction to the magnetic minerals. The combined decision-making of these two monitoring methods results in more precise monitoring and higher sorting control accuracy, ensuring low tailings and smooth operation. The equipment's self-optimization function ensures stable output grade regardless of changes in the incoming ore load. The system can be configured with a single parameter in the central control room based on the iron concentrate product specifications, and the system automatically adjusts to the optimal operating state. When the properties of the ore deteriorate and the actual on-site test results show a low iron concentrate grade (lower than the iron concentrate grade set by the control system (for example, 65%)), the system automatically reduces the magnetic field strength, increases the system water supply, and increases the amount of impurities overflowing, thereby improving the final iron concentrate grade; when the actual on-site test results show a high iron concentrate grade (higher than the iron concentrate grade set by the control system (for example, 65%)), the system automatically increases the magnetic field strength, reduces the system water supply, and reduces the amount of impurities overflowing, thereby reducing the final iron concentrate grade to the iron concentrate grade set by the control system.

[0045] The operation method of the elutriation system includes the following steps: After the 0-1mm iron ore pulp is graded and ground in the ball mill, it follows the magnetic separation-fine screening process. The fine screen has a mesh size of 0.075mm. The product on the screen is returned to the ball mill for re-grinding, and the product under the screen enters the washing system to remove fine-grained lean intergrowths. The ore grade before entering the washing system is (62-65)%, and the washing system processing capacity is ≥23~29 t / h / unit, the feed concentration is 50%, the feed particle size is -325 mesh, accounting for 76-82%, the concentrate yield is more than 85%, the water consumption of a single device is 80-120m3 / h, the ore density is 4.7t / m3, the pulp density is 1.65t / m3, the equipment operation rate is ≥91%, the inner cylinder 3-1 of the washing system separation cylinder has a diameter of φ1200mm, the magnetic field strength of the washing system can be automatically adjusted to 70-150KA / m, the washing system can increase the iron concentrate grade by 2%-3%, that is, reaching the concentrate (64-68)%. When the washing system is working, the iron ore slurry is tangentially fed into the concentrate slurry mixer 1 from the tangential feed port 1-1, and the iron ore slurry swirls along the ore outlet hole at the bottom of the concentrate slurry mixer 1 into the washing cylinder 3. The PLC controller generates different excitation currents through the excitation power supply module according to the different properties of the ore source, and passes through multiple groups of excitation coils 7 Different pulse vibration magnetic fields are generated to form a constant control tail magnetic field area, a circulating magnetic field area and a constant compensation magnetic field area, so that the iron ore slurry in the washing cylinder 3 is dispersed and agglomerated multiple times and moves downward; the magnetic agglomeration and magnetic chain are interrupted and dispersed by the automatically rotating stirring impeller 8, and the pressure of the washing water of the direct current water valve 6-7 and the swirl water valve 6-6 is adjusted according to the properties, particle size, density and concentration of the ore to ensure the ore washing effect and all the gangue is floated and washed away; under the action of the rising direct current water and swirl water in the lower part of the selection area, the magnetic agglomeration and magnetic chain mixed with the single waste rock and the intergrown gangue are floated together, because the gangue has a lighter specific gravity, and after being impacted by the rising water flow, they are collected by the overflow trough 2 to the tailings outlet 2-1 and discharged to form tailings; in addition, most of the iron concentrate has a heavier specific gravity and a larger density, and the heavier particles settle in the washing belt and are discharged from the lowest concentrate outlet 3-5 after settling to form iron concentrate. During the washing process, the opening of the anti-blocking flushing and water supply valve can be adjusted according to the properties, particle size, density and concentration of the ore to ensure the stable operation of the equipment's water supply system; at the same time, based on the real-time monitoring data of the overflow concentration sensor, middle concentration sensor, underflow concentration sensor, underflow pressure sensor, and flow meter, combined with the database set value, the working condition changes are identified, the optimal operation mode is selected, and the feed properties, material quantity and water pressure fluctuations are accurately judged. Through the PLC controller, the excitation power supply module, concentrate outlet control valve, DC water valve, and swirl water valve are controlled to adjust the magnetic field parameters, valve opening, and water volume.

[0046] From ball mill grinding, fine screen particle size classification, pan washing, gangue overflow, coarse particles returning to the ball mill for grinding and other ore monomer dissociation activities, through the interlocking of pan washing time and calculation of feeding amount, washing current and slurry load detection of pan washing system, the feeding amount is automatically calculated to achieve continuous and accurate feeding of ore at a constant flow rate, stabilize washing current and magnetic field strength, improve washing efficiency, and accurately meet the needs of pan washing monomer dissociation; therefore, the entire pan washing system's washing, overflow, sand settling, transportation, and magnetic chain aggregation repeated interruption process realizes an automatic cycle washing process.

[0047] It should be noted that, in the foregoing, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any actual relationship or order between these entities or operations. Furthermore, the terms "include," "comprises," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, article, or device comprising a series of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or device. Furthermore, the terms "front," "rear," "left," "right," "upper," and "lower" herein are all referenced to the placements shown in the accompanying drawings. Finally, it should be noted that the above embodiments are intended only to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art will appreciate that modifications may be made to the technical solutions described in the foregoing embodiments, or that some of the technical features therein may be replaced with equivalents. Such modifications or replacements do not deviate from the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A washing system for efficient washing of iron ore, characterized by: The ore washing machine is a kind of ore concentrate mixer, and the ore concentrate mixer is a kind of ore washing machine, and the ore concentrate mixer is a kind of ore washing machine. The ... A stirring impeller is provided, and assembly flanges are provided above and below the middle main shaft of the stirring impeller, and the upper and lower assembly flanges are fixed to the wall of the inner cylinder through round steel; the lower part of the washing cylinder is filled with ore washing water through the ore washing water channel; a vortex water pipe is provided at the lower part of the ore washing water channel main pipe, and the vortex water pipe supplies water along the tangent spiral direction of the inverted cone cylinder, and a direct current water pipe is provided at the upper part of the ore washing water channel main pipe, and the direct current water pipe supplies water to the central ore washing port at the lower part of the cylinder, and the ore washing port is a lower cylinder connected to the upper inverted frustum structure; the control system includes a PLC controller, a sensor, an excitation power supply module, a water supply control module and a concentrate outlet control valve, and the sensors include an overflow concentration sensor in the overflow trough, a middle concentration sensor in the middle of the cylinder, an underflow concentration sensor and an underflow pressure sensor at the bottom of the cylinder; the excitation power supply module generates different currents to excite the excitation coil to generate a magnetic field; the water supply control module includes a flow meter, a vortex water valve, a direct current water valve, and an anti-blocking flushing regulating water supply valve.

2. The washing system for efficient iron ore washing according to claim 1, characterized in that: The number of the tangential feeding ports is 2-4 groups; the diameter of the ore outlet holes is 5-25 mm, and the spacing is 50-100 mm.

3. The washing system for efficient iron ore washing according to claim 1, characterized in that: The overflow trough and the washing cylinder are connected by continuous welding.

4. The washing system for efficient iron ore washing according to claim 1, characterized in that: The inner surface of the inner cylinder is pasted with a wear-resistant rubber plate with a thickness of 2-4 mm; the outer surface of the outer cylinder is coated with a polysulfide epoxy resin protective coating.

5. The washing system for efficient iron ore washing according to claim 1, characterized in that: An anti-blocking flushing and regulating water supply valve is provided at the lower part of the inverted cone cylinder, and the anti-blocking flushing and regulating water supply valve is an electric regulating butterfly valve.

6. The washing system for efficient iron ore washing according to claim 1, characterized in that: The multiple groups of excitation coils include a constant tail magnetic field coil at the top, a circulating magnetic field coil in the middle and a constant compensation magnetic field coil at the bottom. The excitation power supply module is used to achieve fast instantaneous current switching, generating different currents, and then generating millisecond-level high-frequency pulse vibration magnetic fields according to the different currents, thereby generating different magnetic fields; each group of excitation coils uses high-strength thermal conductive silicone to protect the excitation coil, and each group of excitation coils is also provided with a group of temperature transmitters.

7. A control method for an elutriation system for efficient iron ore washing, comprising the following steps: S1. The iron ore slurry is fed into the concentrate slurry mixer tangentially from the tangential feeding port, and the iron ore slurry swirls along the outlet hole at the bottom of the concentrate slurry mixer and enters the washing cylinder; S2, the PLC controller generates different excitation currents through the excitation power supply module according to the different properties of the ore source, and generates different pulse vibration magnetic fields through multiple sets of excitation coils, forming a constant tail control magnetic field area, a circulating magnetic field area and a constant compensation magnetic field area, so that the iron ore slurry in the washing cylinder is dispersed and agglomerated multiple times, and moves downward; S3. Adjust the pressure of the washing water of the direct current valve and the swirl valve according to the properties, particle size, density and concentration of the ore to ensure the washing effect and all the gangue is floated and washed away; S4. Adjust the opening of the anti-blocking flushing and water supply valve according to the ore properties, particle size, density and concentration to ensure the stable operation of the equipment water supply system; S5. Based on the real-time monitoring data from the overflow concentration sensor, middle concentration sensor, underflow concentration sensor, underflow pressure sensor, and flow meter, combined with the database setting values, identify changes in operating conditions, select the optimal operating mode, accurately determine the feed properties, material quantity, and water pressure fluctuations, and control the excitation power supply module, concentrate outlet control valve, DC water valve, and swirl water valve through the PLC controller to adjust the magnetic field parameters, valve opening, and water volume.

8. The control method for an elutriation system for efficient iron ore washing according to claim 7, characterized in that: In the S2 process, the iron ore slurry swirls into the washing cylinder and rotates to impact the stirring impeller. The stirring impeller rotates under the impact of the iron ore slurry, continuously interrupting the magnetic agglomeration of the iron ore slurry, increasing the length of the magnetic chain and the number of magnetic reversals of the minerals, and separating the gangue minerals contained in the magnetic chain. At the same time, the guiding effect of the stirring impeller increases the rotation of the iron ore slurry and increases the ore washing time.

9. The control method for an elutriation system for efficient iron ore washing according to claim 7, characterized in that: The constant tail magnetic field area is formed by the top constant tail magnetic field coil. The two groups of excitation coils are excited in turn according to the set time, and constant and alternating magnetic fields are generated according to different time settings to control tailing and reduce the magnetic iron grade in the tailings; the circulating magnetic field area is formed by the middle circulating magnetic field coil. When working, the two adjacent groups of excitation coils are alternately powered according to the set time to form a circulating excitation, generate a circulating separation magnetic field, control the length of the magnetic chain, the size of the magnetic agglomeration and the downward speed of the magnetic chain, change the time the mineral stays in the washing cylinder, and control the grade of the iron concentrate; The constant compensation magnetic field zone is formed by the constant compensation magnetic field coil, which generates a background magnetic field to prevent magnetic agglomeration of the magnetic flux and the formation of central magnetic voids, thereby ensuring that the minerals are evenly distributed at the bottom of the washing cylinder; the temperature transmitter on each set of excitation coils monitors the working temperature of the excitation coils. When the temperature of the excitation coil exceeds the preset temperature of 70°C, an alarm is issued and fault cooling processing is performed, that is, the washing system automatically increases the direct current cooling water flow rate to reduce the temperature of the excitation coil; when the temperature exceeds the preset temperature of 110°C, the washing system automatically stops the power supply to the set of excitation coils.

10. The control method for an elutriation system for efficient iron ore washing according to claim 7, characterized in that: Overflow concentration sensors, middle concentration sensors, and underflow concentration sensors are used to directly measure the magnetic content in the iron ore slurry, and the magnetic content data is transmitted to the PLC controller of the control system. The PLC controller adjusts the magnetic field strength according to the amount of magnetic matter in the overflow product and iron ore concentrate product to reduce the loss of magnetic matter in the overflow; the overflow concentration sensor and underflow concentration sensor are inductive oscillation type, with winding coils inside the probes. When magnetic matter in the iron ore slurry passes through the winding coils, the magnetic induction current of the coils will be changed; the PLC controller adopts an adaptive intelligent PLC control program and can be equipped with an optional remote communication module. Through the management of the upper computer, remote centralized control of the control room is realized, and remote start and stop, remote monitoring and setting of operating parameters, and remote fault monitoring and self-diagnosis are realized.

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