27 results about "Demagnetizer" patented technology

The utility model provides a demagnetizer for a bearing ring. The demagnetizer comprises a rack, the transmission roller conveying mechanism is arranged in the length direction of the rack; the demagnetizing mechanism is installed in the middle of the rack and arranged in the width direction of the rack and comprises a supporting frame installed on the rack, an upper magnet yoke assembly capable of ascending and descending along the supporting frame and a lower magnet yoke assembly installed on the rack and arranged right opposite to the upper magnet yoke assembly; the upper magnet yoke assembly comprises a first U-shaped magnet yoke and first coils, an opening of the first U-shaped magnet yoke faces downwards, and the first U-shaped magnet yoke is wound with two sets of parallel first coils. The lower magnet yoke assembly comprises a second U-shaped magnet yoke and second coils, an opening of the second U-shaped magnet yoke faces upwards, and two sets of parallel second coils are wound on the second U-shaped magnet yoke; the first coil and the second coil are connected in parallel. By adjusting the height of the upper magnet yoke assembly and the magnetic field intensity generated by the coil, effective demagnetization of the bearing ring is realized.

The utility model discloses automatic demagnetization conveying equipment for a hydraulic support stand column. The automatic demagnetization conveying equipment comprises a conveying assembly. Through the combination of the transportation assembly, the demagnetizer, the transportation tray, the water collecting tank and the stand column, the hydraulic support stand column demagnetizer realizes the integrated operation from transportation to demagnetization of the hydraulic support stand column. According to the integrated design, intermediate links are reduced, the production efficiency is improved, the equipment can automatically complete demagnetization treatment of the stand column, manual intervention is reduced, meanwhile, the production safety is improved, and the trundles are fixedly installed on the left side of the bottom of the water collecting tank, so that the equipment is convenient to move and position; the transportation tray and the transportation assembly are fixedly installed, and the stability of the stand column in the conveying process is ensured; the demagnetizer is located at the top of the conveying assembly, the stand columns can be demagnetized conveniently, the equipment is suitable for hydraulic support stand columns of different specifications and sizes, high universality and adaptability are achieved, and the problem that in the stand column assembling process, a stand column demagnetizing technology and specific demagnetizing equipment are lacked is solved.

The application belongs to the technical field of elutriation equipment, and particularly relates to an electromagnetic ore dressing device, which comprises a desliming magnetic separation column, an intermediate treatment device and a cleaning magnetic separation column. The intermediate treatment device comprises a rack, an intermediate hopper, a jet device and a scattering cabin. The intermediate hopper and the jet device are fixedly connected with the rack. The concentrate discharge pipe of the desliming magnetic separation column is sequentially communicated with a harmonic wave demagnetizer and a feeding pipe. The concentrate discharged from the concentrate discharge pipe of the desliming magnetic separation column enters the intermediate hopper through the harmonic wave demagnetizer and the feeding pipe in sequence. The jet pipe of the jet device is communicated with the scattering cabin. A lining plate is arranged in the scattering cabin and oppositely arranged with the jet pipe. The scattering cabin is provided with a discharge hopper which is communicated with the ore feeding opening of the cleaning magnetic separation column through a pipeline. The short and thick desliming magnetic separation column and the slender cleaning magnetic separation column are combined, and the magnetic field and the flushing water are independently adjusted, so that the quick desliming and high-precision separation are considered, and the adaptability is high.

The application discloses a kind of fine-grained vanadium-titanium iron concentrate filtration pretreatment methods, comprising the following steps: fine-grained vanadium-titanium iron concentrate and water are mixed and the mass fraction of the fine-grained vanadium-titanium iron concentrate in the obtained suspension is adjusted to predetermined concentration, obtain first slurry;First slurry is passed through demagnetizer, and demagnetization is carried out, and second slurry is obtained;Second slurry is treated with ultrasonic wave, and third slurry is obtained;Third slurry is mixed with a predetermined amount of flocculating agent and then sent into a magnetic separation column after stirring, the operating parameters of the magnetic separation column are adjusted, the height difference between the mixed slurry in the magnetic separation column cylinder and the overflow surface is controlled, and the mass fraction of fine-grained vanadium-titanium iron concentrate in the fourth slurry flowing out of the magnetic separation column is controlled to be a predetermined concentration, and the flocculating agent is prepared from corn starch;Vacuum filtration is carried out on the fourth slurry.It is beneficial to increase the agglomeration diameter of fine-grained vanadium-titanium iron concentrate particles before filtration, reduce the moisture content of the product obtained after filtration of fine-grained vanadium-titanium iron concentrate, and improve the filtration efficiency.

The application belongs to the technical field of material processing, and discloses a demagnetizer and a slurry demagnetization method. The demagnetizer comprises a fixing frame, a material pipe, a magnetic rod device, a scraper device, a power driving device and a limiting device. The material pipe is arranged on the fixing frame, and the material pipe has a material channel. The magnetic rod device comprises a rotating table and a magnetic rod connected with the rotating table. The rotating table is rotatably arranged on the fixing frame, and the magnetic rod is arranged in the material pipe. The scraper device comprises a rotating piece, a scraper and a transmission piece. The magnetic rod is arranged in a sliding hole of the scraper. The rotating piece is rotatably arranged on the rotating table, and the rotating piece is in transmission connection with the scraper through the transmission piece. The power driving device is connected with the rotating piece and drives the scraper to move axially. When the limiting device is in a first position, the rotating table is fixed on the rotating piece through the limiting device. When the limiting device is in a second position, the rotating table is fixed on the fixing frame through the limiting device. The demagnetizer does not need to reserve lifting space of a scraper driving shaft above the demagnetizer, so that the overall height of the demagnetizer can be reduced.

The invention discloses a demagnetizing and filtering trolley, and relates to the technical field of circulating water filtration, the demagnetizing and filtering trolley comprises a trolley body and a demagnetizing device, ball valves are symmetrically arranged right above the trolley body, the output ends of the ball valves are connected with injection pipe fittings, the outer sides of the injection pipe fittings are connected with a supporting frame, the supporting frame is arranged right above the trolley body, and the demagnetizing device is arranged on the trolley body. A circulation mechanism is arranged over the vehicle body and drives liquid to flow through the demagnetizer, and a high-intensity magnetic field environment is constructed through a built-in magnet assembly of the circulation mechanism. When slag needs to be discharged, power is cut off to demagnetize the magnet assembly, and under the action of fluid pressure or gravity, metal particles adsorbed on the surface of the magnet flow to the blow-down valve along with liquid to complete impurity emptying operation. The circulating mechanism drives the liquid to continuously flow through the demagnetizer to form a circulating flow path, so that ferromagnetic impurities in the liquid have more opportunities to be in contact with a high-intensity magnetic field area, the demagnetizing effect is further improved, and it is ensured that the ferromagnetic impurities in the liquid are fully adsorbed.

The utility model relates to the field of aluminum foil production, in particular to a magnetic substance winding and removing device of a splitting machine, which comprises a support, a winding roller is arranged in the support, and limiting grooves are arranged at two ends of the winding roller on the support. The pressing frame is locked through the locking frame, the rotating sleeve pushes the winding roller to abut against the position between the first supporting wheel and the second supporting wheel through the overturned pressing frame, then rapid fixing of the winding roller is completed, and the overturning air cylinder drives the frame type demagnetizer to overturn so as to demagnetize aluminum foil wound on the winding roller. The frame type demagnetizer is arranged on the frame type demagnetizer, magnetic substances attached to the top of the aluminum foil lose magnetism, the magnetic substances on the top of the aluminum foil fall off along with rotation of the winding roller, meanwhile, the electromagnetic block on the frame type demagnetizer is used for adsorbing the bottom of the aluminum foil to be wound, and therefore the magnetic substances on the bottom of the aluminum foil are removed and prevented from being wound into an aluminum coil.

The utility model relates to an ultra-pure polymer circulating, homogenizing and demagnetizing system which comprises a homogenizing stock bin, and a discharge port of the homogenizing stock bin is connected with a feed end of an automatic demagnetizing device through a pipeline; the discharging end of the automatic demagnetizing device is provided with two branch pipes, and the branch pipes comprise a qualified material output branch and a finished product collecting unit, and the circulating branch is communicated with the homogenizing stock bin through a material returning pipeline and is used for returning the substandard materials to the homogenizing stock bin for secondary homogenizing and demagnetizing treatment. Compared with the prior art, the system has the advantages that the automatic demagnetizing device and the circulating branch are arranged in the system, so that efficient, continuous and clean industrial production is realized, and the system is particularly suitable for large-scale production of high-end polyolefin products such as ultra-clean high-purity polyethylene.

1. Name of the product in this design: Demagnetizer. 2. Purpose of this design: To demagnetize metal products. 3. The key design feature of this product is its shape. 4. The image or photograph that best illustrates the key design points: Design 1 3D view. 5. Design 1 is designated as the basic design.

The invention provides a steam turbine rotor demagnetization method which is easy to operate and can quickly and efficiently complete steam turbine rotor demagnetization, and relates to the technical field of demagnetization. The steam turbine rotor demagnetization method comprises the steps of rotor shaft demagnetization, specifically, direct current coils are wound at the two ends of a rotor shaft respectively, and then the two ends of the rotor shaft are demagnetized in sequence through a demagnetizer by means of a direct current coil method till residual magnetism meets the requirement; wherein in the demagnetization process, a demagnetizer wiring terminal is alternately connected positively and negatively, so that magnetic poles of a magnetic field generated by the direct-current coil are alternately changed; demagnetizing the rotor blade: winding a lead on the columnar iron core to form an electromagnetic coil; when the rotor blade is demagnetized, one end of the columnar iron core abuts against one side of the tail end of the rotor blade, then alternating current is led into the wire, the columnar iron core becomes an electromagnet, and the rotor blade is demagnetized through a demagnetizer by means of an alternating current demagnetization method till the residual magnetism of the rotor blade meets the requirement.

This utility model relates to the field of lithium salt impurity removal technology. Addressing the problem that excessive magnetic impurities in the washing water after crude lithium salt purification affect the purity of the lithium salt product during recycling, this invention specifically discloses a secondary evaporation washing water recycling system for lithium salt purification. The system includes a primary evaporation crystallization system and a secondary evaporation crystallization system connected in sequence. The discharge end of the secondary crystallization evaporation system is sequentially connected to a demagnetizer, a distiller, and a belt centrifuge. The discharge end of the belt centrifuge is equipped with a reflux pipe, the water outlet of which is connected to both the primary and secondary evaporation crystallization systems via multiple branch pipes. This further treats and removes impurities from the secondary evaporation washing water, which is then fed into both evaporation crystallization systems, enabling the reuse of the washing water and preventing the loss and waste of residual lithium elements.

The utility model discloses a device for automatically cleaning a magnetic core of a powder demagnetizing machine by applying a sound wave principle. The device comprises a beam sound conduction cylinder and a titanium alloy sound wave generator, the beam sound conduction cylinder is trumpet-shaped, and the titanium alloy sound wave generator is mounted at one end, with a smaller opening diameter, of the beam sound conduction cylinder; the outer side of the other end of the sound transmission cylinder is fixedly connected with a connecting flange; the side, close to the titanium alloy sound wave generator, of the connecting flange is fixedly connected with a sealing protection cover, the sound restraining conduction barrel and the titanium alloy sound wave generator are both located in the sealing protection cover, and an air inlet connector of the titanium alloy sound wave generator extends out of the sealing protection cover and is in sealing connection with the sealing protection cover. The directional gas sound wave generator and the sound wave beam set device are utilized, materials adsorbed on the medium net are removed through sound wave energy, thorough removal can be achieved, foreign matter cannot be generated, equipment cannot be damaged, and meanwhile the device is easy and convenient to use, simple in structure and convenient to produce and manufacture.

The utility model relates to a double-pulse demagnetizer, which belongs to the technical field of demagnetizing equipment and comprises a pipe body, a demagnetizing coil is wound on the pipe body and comprises a first coil and a second coil, the first coil and the second coil are arranged in parallel and share a first terminal and a second terminal, and the first terminal and the second terminal are connected in parallel. The device is mainly used for ore pulp of a dressing plant, is provided with pipeline-type flat copper double coils, rapidly charges and discharges a capacitor bank under the cooperation of an oscillation circuit, enables the double coils to work simultaneously, adjusts the double coils according to the permutation and combination optimization principle of a magnetic system, operates in the optimal current flow direction, and forms an annular strong magnetic field; meanwhile, the tolerance of a control system and a demagnetizing coil is improved, and an extremely high demagnetizing magnetic field is formed by strong current and high power, so that a good demagnetizing effect is achieved, and the maximum output power can reach 22kw.

A system for removing iron ore particles adhered by magnetic hysteresis to a magnetic matrix of a vertical magnetic separator, the vertical magnetic separator having a separation ring with a magnetic matrix; an ore feed inlet an ore accumulation vessel positioned in the lower portion of the magnetic matrix and having an outlet for low magnetic-susceptibility material; a magnetic field-generating device adapted to generate a magnetic field in the region of the accumulation vessel; at least one collection tray positioned internally to the magnetic matrix and adapted to collect material with greater magnetic susceptibility detached from the magnetic matrix; and a collecting container adapted to receive the material with greater magnetic susceptibility from at least one collecting tray. The system further includes a demagnetizer; a mechanical device for cleaning the magnetic matrix positioned at a position subsequent to the demagnetizer; and at least one device generating jets of compressed air.

The utility model is applicable to the technical field of electromagnetic separation, and provides a high-field-intensity full-automatic slurry electromagnetic iron remover which comprises an equipment main body, the equipment main body comprises a material passing cavity, a demagnetizer and a feeding pipe, the feeding pipe and the material passing cavity are both communicated with the demagnetizer, and a coil and a magnetic medium are arranged in the demagnetizer; the stirring device comprises a sealing cover, a stirring piece, rotating wheels, a transmission belt, a rotating motor and a belt rotating rod, one rotating wheel is connected to the belt rotating rod, and an output shaft of the rotating motor is connected to the other rotating wheel; according to the stirring device, when raw material slurry enters the material passing cavity, the started rotating motor drives the rotating wheel to rotate, so that the belt rotating rod and the stirring pieces distributed on the belt rotating rod axially rotate around the belt rotating rod, the raw material slurry in the material passing cavity is stirred, and the phenomenon that the raw material slurry is possibly distributed unevenly or agglomerated is avoided.

The application discloses a permanent magnet rail degaussing device and relates to the technical field of rail degaussing.The permanent magnet rail degaussing device comprises a shell and a degaussing assembly arranged on the inner wall of the shell; the shell comprises a top mounting plate and first and second side mounting plates arranged on the two sides of the bottom of the top mounting plate; the bottom of the top mounting plate is provided with a pulley which slides along the rail; the degaussing assembly comprises a top degaussing group, a rail head degaussing group and a rail waist degaussing group which generate continuously commutated degaussing magnetic fields respectively; the top degaussing group is arranged on the top mounting plate; and the first and second side mounting plates are both provided with the rail head degaussing group and the rail waist degaussing group oppositely. The top degaussing group, the rail head degaussing group and the rail waist degaussing group generate continuously commutated degaussing magnetic fields respectively, so that the main circuit breaker of the motor train unit does not abnormally jump, thereby solving the problem that the existing degaussing method and degaussing device cannot be applied to the rail.

The utility model relates to a demagnetizer with an internal spiral blade, which comprises a demagnetizer pipe body, a demagnetizing coil arranged outside the demagnetizer pipe body and connecting flanges arranged at two ends of the demagnetizer pipe body, and is characterized in that the internal spiral blade is arranged in the demagnetizer pipe body. The demagnetizer disclosed by the utility model has the advantages that ore pulp flows through the demagnetizer pipe body, a variable demagnetizing magnetic field is generated under the action of the coil, and iron ore particles in the ore pulp are demagnetized under the action of the demagnetizing magnetic field. The inner spiral blade arranged in the demagnetizer pipe body prolongs the route length of ore pulp flowing through the demagnetizing coil, so that the ore pulp can obtain longer demagnetizing time, the demagnetizing effect is improved, meanwhile, the ore pulp flows through the spiral blade in the demagnetizing coil, disturbance to the ore pulp is intensified, and magnetic agglomeration in the ore pulp is dispersed more easily.

This invention discloses a method for removing shot adsorbed on the lower surface of shot-blasted steel plates, relating to the field of steel plate surface treatment technology. The method includes: fixing at least one demagnetizer on the exit side of a shot blasting machine, with a pre-existing gap between the demagnetizer and the lower surface of the steel plate; when the shot-blasted steel plate reaches a preset position, activating the demagnetizer to generate an alternating magnetic field to demagnetize the steel plate, and controlling the steel plate to run at a first speed; after the steel plate has completely left the demagnetizer, stopping the demagnetizer and activating air blowing to clean the surface of the demagnetizer. This invention, through the organic combination of online demagnetization and automatic blowing, achieves thorough removal of shot adsorbed on the lower surface of nickel-containing steel plates, fundamentally solving the quality problem of shot indentation.

The utility model provides a granular silicon production system for recovering, selecting and grinding falling materials, which comprises a recovered material moving tank for storing the falling materials, and a product sieve for primary sieving, a discharging port of the product screen is connected with a feeding port of light impurity removing and dust blowing equipment used for removing light impurities, a discharging port of the light impurity removing and dust blowing equipment is connected with a feeding port of a temporary storage tank, and a discharging port of the temporary storage tank is connected with a feeding port of a magnetism removing machine used for removing magnetic impurities. A non-magnetic material discharge port, for outputting non-magnetic materials, of the demagnetizer is connected with a feed port of the screening machine for screening the materials, a discharge port, for outputting large-particle materials, of the screening machine is connected with a feed port of the grinding raw material tank, and a small-particle discharge port, for outputting small-particle materials, of the screening machine is connected with the sundry collecting tank; a discharge port of the grinding raw material tank is connected with a feed port of a grinding machine for grinding materials, and a discharge port of the grinding machine is connected with a silicon powder tank.

A bearing parts cleaning box includes a frame, a cleaning tank on top of the frame, an installation groove on the side of the cleaning tank, a liquid storage tank below the frame, a lift pump mounted on the side of the liquid storage tank, the outlet of the lift pump connected to the cleaning tank via a pipe, and the bottom of the cleaning tank connected to the liquid storage tank via a pipe. A demagnetizer is installed in the installation groove, and a demagnetizing platform is provided on the surface of the demagnetizer. Compared with the prior art, this bearing parts cleaning box, by simultaneously setting up a cleaning tank and a demagnetizer on top of the frame, can clean bearing parts and demagnetize them after cleaning, making it convenient to use.

The invention belongs to the technical field of elutriation equipment, and particularly relates to an electromagnetic mineral separation device which comprises a desliming magnetic separation column, an intermediate treatment device and a concentration magnetic separation column. The intermediate treatment device comprises a rack, an intermediate hopper, an ejector and a scattering cabin; the middle hopper and the jet device are fixedly connected with the rack; a concentrate discharge pipe of the desliming magnetic separation column is sequentially communicated with a harmonic wave demagnetizer and a feeding pipe; concentrate discharged by a concentrate discharging pipe of the desliming magnetic separation column enters the middle hopper through the harmonic wave demagnetizer and a feeding pipe in sequence; an ejection pipe of the jet device is communicated with the scattering cabin, a lining plate is arranged in the scattering cabin, and the lining plate and the ejection pipe are oppositely arranged; and the scattering cabin is provided with a discharge hopper, and the discharge hopper is communicated with an ore feeding opening of the concentration magnetic separation column through a pipeline. The short and thick desliming magnetic separation column and the long and thin fine separation magnetic separation column are combined, the magnetic field and washing water are independently adjusted, rapid desliming and high-precision separation are both considered, and adaptability is high.

The application discloses a magnetic removing machine, a control method and a negative material production line. The magnetic removing machine comprises a mounting frame, an electromagnetic body fixed on the mounting frame, a cylinder body penetrating through the electromagnetic body and connected with the electromagnetic body, a first screen mesh arranged in the cylinder body and corresponding to the electromagnetic body, a tee joint assembly connected with the bottom of the cylinder body, a power module, a permanent magnet coil, a second screen mesh, a vibrating mechanism, a magnetic field detection probe and a control module. The permanent magnet coil is sleeved outside the cylinder body and located above or below the electromagnetic body. The second screen mesh is made of a permanent magnet material and arranged in the cylinder body and corresponding to the permanent magnet coil. The vibrating mechanism is arranged on the cylinder body and used for generating vibration. The magnetic field detection probe is used for detecting the magnetic induction intensity of the second screen mesh. The permanent magnet coil, the control module and the power module are electrically connected. The control module is electrically connected with the magnetic field detection probe, the vibrating mechanism and the tee joint assembly. The application reduces the energy consumption of equipment operation.

The invention discloses a magnetic foreign matter removing device and method. The magnetic foreign matter removing device comprises a reactor, a magnetizing coil, a reverse suspension coil and a liquid film demagnetizing device. The reactor is provided with a demagnetizing cavity, a feed port and a discharge port, the feed port is communicated with the upper end of the demagnetizing cavity, and the discharge port is communicated with the lower end of the demagnetizing cavity; the magnetizing coil is arranged in the demagnetizing cavity and is positioned at the upper part of the demagnetizing cavity; the reverse suspension coil is arranged in the demagnetizing cavity and located below the magnetizing coil, and the reverse suspension coil and the magnetizing coil form a forward and reverse magnetic field; the liquid film demagnetizing device is arranged in the demagnetizing cavity and located between the magnetizing coil and the reverse suspension coil, and the liquid film demagnetizing device is used for forming a magnetic fluid liquid film. According to the invention, the magnetic foreign matters can be efficiently removed on the premise of not changing the material characteristics of the material.

This invention relates to the field of material sorting technology, and in particular to a screening system for separating magnetic substances from concrete aggregates; it includes a permanent magnet sorting device, an electromagnetic iron removal device, and a demagnetizing device; the permanent magnet sorting device includes a first conveyor belt and a permanent magnet drum disposed at the end of the first conveyor belt, separating ferromagnetic substances with larger particle size and stronger magnetism from the aggregates; the electromagnetic iron removal device includes a feed hopper and a magnetic roller transversely inserted into the feed hopper, which uses strong electromagnetic attraction to accurately capture tiny ferromagnetic particles attached to the surface of the aggregates and weakly magnetic substances wrapped by the material; the demagnetizing device includes a second conveyor belt and a demagnetizer disposed above the second conveyor belt, which generates a decaying magnetic field to eliminate residual magnetism in the aggregates; this significantly improves the thoroughness of ferromagnetic impurity separation, solves the problem of incomplete impurity removal in traditional single magnetic separation methods, and ensures the purity of the aggregates.

This invention provides a square screen and a demagnetizer. The square screen includes an outer perimeter, a sleeve coaxially disposed within the outer perimeter, and multiple magnetic strips symmetrically arranged along the horizontal center line H and the vertical center line M of the outer perimeter. The magnetic strips connect the outer perimeter and the sleeve. The multiple magnetic strips are connected in a forward and reverse interlocking manner in the Z direction to form square screen holes. This invention features strong magnetic conductivity, high structural strength, light weight, low impact resistance during vibration, and durability.

The invention provides powder feeding demagnetizing premixing equipment and a premixing method.A premixing stirring tank is located on a weighing forklift and comprises a tank body and a stirring paddle, the tank body is provided with a containing space, the stirring paddle is arranged in the containing space of the tank body, a premixing filtering blowback device is arranged outside the tank body and communicated with the containing space, and the premixing filtering blowback device is arranged in the containing space of the tank body. The vibration demagnetizer is arranged on the tank body, the vibration demagnetizer is communicated with the containing space, one end of the sucking and conveying pipeline is connected with the vibration demagnetizer, and the other end of the sucking and conveying pipeline is used for being inserted into a powder container, so that powder in the powder container is sucked into the vibration demagnetizer and then enters the premixing stirring tank. According to the invention, raised dust can be reduced, the production environment is improved, powder magnetic foreign matters are reduced, the subsequent voltage consistency is ensured, the feeding weight precision is improved, the problem of proportion imbalance is avoided, the product quality is improved, dry powder premixing is realized, and the production efficiency is improved.

The invention belongs to the technical field of inorganic chemistry, and discloses a preparation method of high-purity nano titanium dioxide, which comprises the following steps: respectively filtering a reaction raw material TiCl4 and reaction gas, and mixing in a reactor; igniting the obtained mixture, and carrying out combustion reaction in a reaction furnace to obtain a reaction product; the obtained reaction product is input into a deacidification device, deacidification auxiliary gas which is sequentially heated and filtered is input into the deacidification device, the deacidification auxiliary gas and the reaction product are subjected to mutual hedging in the deacidification device for deacidification, and nanometer titanium dioxide is obtained; the temperature of the deacidification auxiliary gas is 450-600 DEG C; and introducing the obtained nano titanium dioxide into a demagnetizer to demagnetize, thereby obtaining the high-purity nano titanium dioxide. According to the preparation method, the content of chlorine, iron, sodium, calcium, copper, zinc, cadmium, chromium, lead and magnetic foreign matters in the nano titanium dioxide product can be effectively controlled while the nano titanium dioxide product with the anatase type crystal proportion higher than 80% is obtained.