WO2022095264A1

WO2022095264A1 - Bauxite organic matter removal method and device

Info

Publication number: WO2022095264A1
Application number: PCT/CN2020/141865
Authority: WO
Inventors: 王晧; 刘春莲; 段小刚
Original assignee: 太原理工大学
Priority date: 2020-11-06
Filing date: 2020-12-30
Publication date: 2022-05-12
Also published as: CN112537789B; CN112537789A

Abstract

A bauxite organic matter removal method and device. The organic matter removal device comprises: a grinding and vibrating screening device, a bauxite bin, a material feeding device, a micro-plasma corona discharge system, an organic matter treatment cavity, a material discharging device, a treated bauxite bin and a control device. The grinding and vibrating screening device is connected to the bauxite bin, the bauxite bin is connected to the material feeding device, the material feeding device is connected to the organic matter treatment cavity, the micro-plasma corona discharge system is connected to the organic matter treatment cavity, the organic matter treatment cavity is connected to the material discharging device, and the material discharging device is connected to the treated bauxite bin; and the treated bauxite bin is connected to a Bayer process aluminum oxide production procedure. The organic matter removal method comprises: firstly, grinding bauxite into 40-100 mesh particles and material-feeding the particles into an organic matter treatment cavity; and starting a micro-plasma corona discharge system to make continuous collision bombardment and a composite reaction occur in the organic matter treatment cavity, so as to remove organic matter from the bauxite. The present invention has low costs and can remove organic matter in one step.

Description

A kind of bauxite organic matter removal method and device

technical field

The invention relates to the field of new metallurgical technology, in particular to a method and a device for removing organic matter from bauxite.

Background technique

The organic matter in bauxite is generally lignin and cellulose under natural conditions such as natural bark and grass roots, as well as humus, fulvic acid, oxalic acid, formic acid, asphaltene, etc. formed after the decomposition of lignin and cellulose. The organic matter content in the bauxite imported from abroad is generally between 0.2% and 0.6% wt. These organic matters cause great difficulties to the production of alumina by the Bayer process.

The process characteristics of the production of alumina by the Bayer process are mother liquor circulation and high temperature, high pressure and high alkali dissolution. Therefore, more than 50% of the organic humic acids in the bauxite are dissolved into the mother liquor and gradually accumulate. The organic matter with larger molecular weight dissolved in the mother liquor will gradually decompose or oxidize into small molecular organic matter, such as humic acid, fulvic acid, lignin, cellulose, and protein into small molecular organic matter such as oxalic acid and acetic acid. These small molecules of organic matter will consume the caustic alkali circulating mother liquor, resulting in an increase in the viscosity of the sodium aluminate solution, a decrease in the interfacial tension, an increase in the consumption of alkali, a decrease in the dissolution rate, and easy foaming during stirring and transportation. The insoluble organic matter coats the bauxite surface, hinders the full contact between the bauxite and the mother liquor, and reduces the dissolution rate of aluminum hydroxide. In the decomposition process, as long as the organic matter concentration in the decomposed stock solution reaches the "critical value" milligram level, the organic matter will occupy the active site of aluminate ions and weaken the seeding effect. The presence of organic matter will also lead to a decrease in the whiteness and particle size of the produced aluminum hydroxide, making it impossible to produce sandy alumina.

The organic matter in bauxite has a huge impact on production, and researchers have made a lot of efforts in the study of methods to control the content of organic matter in Bayer production. Bauxite roasting method, washing method, precipitation method, ion exchange, causticization method, decomposing mother liquor roasting method, solution oxidation method, etc. have all entered the research field, but the effect in industrial application is not ideal. The invention aims to dissociate the organic matter in the bauxite by using the atmospheric micro-plasma corona discharge method without affecting the bauxite dissolution conditions, eliminate the organic matter from the source, and fundamentally solve the problem that the organic matter in the bauxite has an adverse effect on the production by the Bayer process. The effect of alumina.

SUMMARY OF THE INVENTION

In order to solve the above problems, the present invention provides a low-cost and one-time method for removing organic matter from bauxite.

A method for removing organic matter from bauxite, comprising the following steps:

1. Grind and sieve the bauxite into 40-100 mesh particles and put them into the bauxite silo for use;

2. Send the screened bauxite into the organic matter treatment chamber; the organic matter treatment chamber includes a cavity, and a crawler-type bauxite treatment bed or agitator is arranged in the cavity; the crawler-type bauxite treatment bed makes the bauxite in It moves with the crawler during the reaction, and enters the discharge device with the crawler after the reaction; the stirrer stirs the bauxite while the micro-plasma reaction occurs, ensuring fast and uniform reaction and facilitating bauxite discharge;

3. Start the micro-plasma corona discharge system, input electromagnetic energy into the organic matter processing chamber through the multi-phase electrode, ionize the air in the organic matter processing chamber to generate micro-plasma, electrons and high-energy particles in the micro-plasma and bauxite powder Continuous collision and bombardment occurs. Due to the low dissociation energy of the C-H bond in organic matter, hydrogen and active groups are dissociated. These electrons, hydrogen, high-energy particles and active groups continue to undergo excitation, ionization, recombination and three-body recombination reactions to achieve The organic matter in the bauxite is dissociated or oxidized indiscriminately, so that the organic matter in the bauxite can be eliminated without affecting other components in the bauxite.

4. After the treatment, the bauxite temperature is 100-150°C, and the organic matter in the bauxite is dissociated and oxidized into CO ₂ , CO, H ₂ O and N ₂ ;

5. After the treatment is completed, the bauxite enters the treated bauxite silo through the discharge device, and is transferred to the Bayer process alumina production process.

6. The entire process is controlled by PLC or AI artificial intelligence to ensure that each process is continuous and orderly and to ensure proper coordination.

Under normal temperature and pressure, by adjusting the power supply voltage, frequency, power and phase difference, a uniform corona discharge atmospheric microplasma will be generated in the organic matter processing chamber. These electrons and high-energy particles collide with each other and are excited to generate more high ^- energy electrons e- ^* , excited state particles and a wide variety of metastable active particles and active groups, after activation, dissociation, electron capture and ionization, the following reactions occur:

O ₂ →O ₂ ⁺ +e ^−*

N ₂ →N ₂ ⁺ +e ^−*

N ₂ →N+N ⁺ +e ⁻

O ₂ →O+O ⁺ +e ⁻

N+e ^−* →N ^* +e ⁻

O+e ^- →O ^-

O ⁺ +N ^* → O+N ⁺

These high-energy electrons, ions, excited state particles O ^- , N ⁺ , O ₂ ⁺ , N ₂ ⁺ , O ^- , N ^* , O ^* , O ₂ ^- and bauxite particles continue to collide and bombard the result, the bond dissociation energy The lower CH is rapidly dissociated into electrons and active groups, and as a result of the combined action, the organic matter molecules are dissociated and oxidized indiscriminately, and finally become CO ₂ , CO, N ₂ and water. Due to the energy transfer of electrons and particles, the temperature of bauxite particles increased during the treatment process. After the reaction, the bauxite temperature was 100-150 °C; the bauxite particles after the treatment were sent to the bauxite silo after treatment. Forwarded to the Bayer production process.

A bauxite organic matter removal device, comprising: a grinding and vibrating screening device, a bauxite silo, a feeding device, a micro-plasma corona discharge system, an organic matter processing chamber, a discharging device, a treated bauxite silo, control device;

The control device controls the grinding vibration screening device, the feeding device, the micro-plasma corona discharge system, the organic matter processing chamber, and the discharging device;

The grinding and vibrating screening device is connected to the bauxite silo, the bauxite silo is connected to the feeding device, the feeding device is connected to the organic matter treatment chamber, the micro-plasma corona discharge system is connected to the organic matter treatment chamber, and the bauxite treatment device is connected to the discharging device. The discharging device is connected to the treated bauxite silo, and the treated bauxite silo is connected to the Bayer process alumina production process;

The grinding and screening device uses a vortex method, a linear method, a jig method, a rotary method, a swing method, or a pair of roller methods to grind and screen the bauxite, and the vibration frequency is 6 to 700 times/ min, the amplitude is 2-50mm, the bauxite particles are 40-100 mesh after the treatment; the bauxite after grinding and screening is put into the treated bauxite silo;

The feeding device utilizes ultra-dense phase conveying device or vacuum feeding to transport the bauxite to the atmospheric micro-plasma bauxite processing device;

The super-dense phase feeding is to convert the fluidization operation of the bauxite layer into a "gas-solid two-phase" fluid. In this way, the potential energy of the bauxite in the bauxite silo is transferred to the flow direction through this "gas-solid two-phase" fluid, and a pressure gradient is formed, forming bauxite columns of different heights in each equilibrium column. The high bauxite column pushes the bauxite towards the lower column. The conveying capacity of the ultra-dense phase conveying device is 10～300t/h; the flow rate is less than 0.28m/s; the pressure range: 2000～8000Pa.

The vacuum feeding uses negative pressure suction, the vacuum degree is controlled at 5-90kPa, the conveying capacity per hour is 1-300 tons, and the power is 0.25-90kW;

The micro-plasma corona discharge system includes a discharge power source, a multi-phase electrode and a ground electrode; the discharge power source generates a high-frequency high-voltage current with a power of 50W to 300kW, a frequency of 10Hz to 6GHz, a voltage of 1.0KV to 70KV, a multiphase electrode and a ground electrode. Corona discharge atmospheric micro-plasma is generated between the electrodes; the distance between the multi-phase electrode and the ground electrode is 0.1-200 mm, and the generated atmospheric micro-plasma is fully contacted with bauxite particles;

The organic matter processing chamber receives the corona discharge micro-plasma generated by the micro-plasma corona discharge system and the bauxite sent by the feeding device, and ensures that the processed bauxite is transported out. The organic matter treatment chamber is provided with a stirrer or a crawler-type bauxite treatment bed; the size of the organic matter treatment chamber is (300～30000)mm×(200～20000)mm×(200～400000)mm, and the cavity is spherical or cylindrical Or rectangular; the wall of the cavity is made of stainless steel or carbon steel or alloy steel to ensure that the uniform corona discharge atmospheric micro-plasma is generated in the cavity, and the cavity is provided with a feed end and a discharge end; The discharge port of the material end enters the discharge device; the outer casing is provided with a casing; the organic matter treatment chamber is provided with a stirrer or a crawler-type bauxite treatment bed;

The agitator ensures that the micro-plasma reaction is fast and uniform during the bauxite treatment process, and pushes the bauxite to the discharge port after the bauxite treatment is completed, and the agitator rotates at a speed of 1 to 1000 r/min;

The treatment process of the crawler-type bauxite treatment bed is carried out continuously, and the bauxite entering from the feed port is subjected to reaction treatment during the movement of the crawler belt. When the bauxite reaches the discharge port, the treatment ends and enters the discharge device. The moving speed of the crawler is 0.1～20m/min; the bauxite treatment time is 1～600min; the bauxite temperature is 100～150℃ when discharging;

The discharging device uses a bucket discharger or a screw conveyor to discharge the material, and the bucket discharger or the screw conveyor is provided with a protective cover;

Further, the grinding and screening device adopts Renault 520 linear vibrating screen or LN series circular vibrating screen, LNY600-2600 series rocking screen produced by Xinxiang Renault Machinery Co., Ltd.; or PLPZ series composite type produced by Shicheng High Rotation Bearing Co., Ltd. Crusher; the power of the crusher is 0.25-200kW, and the size of the bauxite under the screen is 40-100 mesh;

Further, the ultra-dense phase feeding device adopts PECHINEY ultra-dense phase conveying device. The conveying capacity is 10-300T/h; the flow velocity in the bauxite chute is less than 0.28m/s; the pressure range: 2000-8000Pa.

Further, the vacuum feeder uses vacuum to suck the bauxite into the organic matter processing chamber, such as the ZKS series electric vacuum feeder of Xinxiang Renault Machinery Co., Ltd., with a power of 0.25-30kW;

Further, the micro-plasma corona discharge system includes a discharge power source, a multi-phase electrode and a ground electrode; the multi-phase electrode is connected with the discharge power source by a wire, and the discharge power source provides a high-frequency high-voltage current with a power of 50W to 300kW and a frequency of 10Hz to 6GHz. , the voltage is 1.0kV ~ 70kV; the multi-phase electrode is made of nickel-chromium wire or stainless steel wire, the diameter is between 0.5 and 5mm, the length is between 30 and 300mm, and the number of phases is controlled between 2 and 300, and is connected to the ground. The electrodes are kept at a certain distance during which the air is ionized; the distance between the multi-phase electrode and the ground electrode is between 1.0mm and 300mm; the space between the multi-phase electrode and the ground electrode forms atmospheric micro-plasma corona discharge; the ground electrode can be a cavity Wall or agitator blades or crawler bauxite treatment beds;

Further, the organic matter processing chamber is used to ensure the formation of uniform corona discharge atmospheric micro-plasma in the chamber. The wall material is stainless steel or carbon steel or alloy steel, and the cavity is provided with a feed end and a discharge end; after the treatment is completed, the bauxite directly enters the discharge device from the discharge port of the discharge end; the cavity is equipped with a shell; organic matter treatment A stirrer or crawler-type bauxite treatment bed is installed in the cavity; the multi-phase electrodes of the micro-plasma corona discharge system are distributed on the cavity of the organic matter treatment cavity, and the material of the cavity wall is stainless steel or carbon steel or alloy steel; organic matter treatment The chamber wall or agitator or crawler bauxite treatment bed is grounded to become the ground electrode of the atmospheric micro-plasma discharge device, ensuring that the interior of the organic matter treatment chamber becomes the atmospheric micro-plasma corona discharge area; the organic matter treatment chamber is adjacent to the multi-phase electrode device. The micro-plasma uniform distribution plate ensures uniform discharge atmospheric micro-plasma in the organic matter processing chamber. The micro-plasma uniform distribution plate is an alumina plate or a mullite plate, with a thickness of 3-30 mm, and a gap of 3-30 mm with the multi-phase electrode. 30mm; the feed end of the organic matter treatment chamber is the bauxite inlet, and the discharge end is the bauxite outlet after treatment; the treated bauxite directly enters the discharge device from the bauxite outlet; the organic matter treatment chamber is equipped with a shell for To protect the multi-phase electrode, the shell material can be stainless steel, carbon steel or alloy steel, and the distance from the bauxite cavity is set between 200 and 800mm; the discharge power supply can be integrated between the organic matter processing cavity and the shell or separated Arrangement; the micro-plasma treatment time of bauxite is 5～600min; the bauxite temperature is 100～150℃ when discharging;

Preferably, a stirrer is installed in the organic matter treatment chamber, which can be JBJ series mixer or DXJ series mixer or DJ series mixer or RF series mixer or KF series mixer or CV series mixer or BLD series mixer from Dawnray Machinery, with a power of 1.1-30KW, The stirrer is connected to the ground electrode;

Preferably, the width of the crawler-type bauxite treatment bed is (500-2000) mm and the length (2000-380,000) mm; the crawler belt is made of stainless steel lined high alumina refractory material or Teflon; the crawler belt The moving speed is 0.1～20m/min, and the crawler treatment bed is grounded;

Further, the treated bauxite enters the treated bauxite silo through the discharging device; the discharging device adopts a bucket conveyor or a screw conveyor to output the bauxite, and the bucket conveyor or screw conveyor is provided with a protective cover; The conveyor adopts the DS series bucket conveyor from China Mining Heavy Equipment; the screw conveyor adopts the GX series conveyor from China Mining Heavy Equipment;

Further, the control device is controlled by PLC or expert device to ensure the accurate control and coordination of each program in the processing process, and the opening and closing of each link is coordinated by the program of the control device. PLC control adopts Omron NX7 controller series or NX1 controller series or NX1P controller series or NJ controller series or industrial PC platform NY series or NX series I/O unit; expert control device is the use of expert control device, such as Emerson Ovation expert control device.

The invention utilizes the collision excitation bombardment effect of electrons, ions and excited state particles generated by atmospheric microplasma corona discharge, dissociates and oxidizes indiscriminate organic matter in bauxite, and effectively solves the problem of organic matter in bauxite.

practicality

The bauxite organic matter treatment device of the present invention is a purchased product, the bauxite organic matter treatment method can be implemented, and the present invention has practicability.

Description of drawings

1 is a schematic diagram of a bauxite organic matter processing device in an embodiment of the present invention;

Fig. 2 is another kind of bauxite organic matter processing device schematic diagram in the embodiment of the present invention 1:

3 is a schematic diagram of another atmospheric microplasma corona discharge generating device in Embodiment 2 of the present invention;

Fig. 4 is the left side view of Fig. 3;

5 is a schematic diagram of another atmospheric microplasma corona discharge generating device in an embodiment of the present invention;

Fig. 6 is the sectional top view of Fig. 5;

Fig. 7 is the bauxite ore XRD analysis figure of embodiment one;

Fig. 8 is the XRD analysis diagram of embodiment one bauxite after atmospheric micro-plasma corona discharge treatment;

Fig. 9 is the XRD analysis figure of embodiment two bauxite ore;

10 is an XRD analysis diagram of the bauxite in Example 2 after the bauxite is treated by atmospheric micro-plasma corona discharge.

In the figure: 1. Control device, 2. Grinding and screening device, 3. Bauxite bin, 4. Feeding device, 5. Micro-plasma corona discharge system, 6. Organic matter processing chamber, 7. Discharging device, 8. Bauxite silo after treatment, 9. Bauxite baffle plate, 10. Shell, 11. Bauxite inlet, 12. Bauxite height control board, 13. Discharge power supply, 14. Multi-phase electrode, 15 , uniform distribution plate, 16, crawler type reaction bed, 17, discharge baffle, 18, discharge port, 19, storage tank, 20, ground electrode, 21, agitator.

Detailed ways

Embodiments of the technical solutions of the present invention will be described in detail below with reference to the accompanying drawings. The following examples are only used to illustrate the technical solutions of the present invention more clearly, and are therefore only used as examples, and cannot be used to limit the protection scope of the present invention.

As shown in Fig. 1 and Fig. 2, the bauxite organic matter removal method provided by the present invention comprises the following steps:

2. Send the bauxite into the organic matter treatment chamber;

3. Start the corona discharge device, and input electromagnetic energy into the organic matter treatment chamber through the multi-phase electrode, so that the air in the organic matter treatment chamber is ionized to generate micro-plasma, and the electrons and high-energy particles in the micro-plasma continuously collide with the bauxite powder. Bombardment, hydrogen and active groups are dissociated due to the low dissociation energy of C-H bonds in organic matter. These electrons, hydrogen, high-energy particles and active groups continue to undergo excitation, ionization, recombination and three-body recombination reactions to realize bauxite. The organic matter in the bauxite is dissociated or oxidized indiscriminately, so as to eliminate the organic matter in the bauxite without affecting other components in the bauxite. After the treatment, the bauxite temperature is 100～150℃;

3-1. A crawler-type bauxite treatment bed is set in the organic matter treatment chamber. The bauxite moves with the crawler during the reaction, and enters the discharge device with the crawler after the reaction is completed;

3-2. A stirrer is installed in the organic matter treatment chamber, and the bauxite is stirred while the micro-plasma reaction occurs, so as to ensure the rapid and uniform reaction and facilitate the bauxite discharge;

4. After the treatment, the organic matter in the bauxite is dissociated and oxidized into CO ₂ , CO, H ₂ O and N ₂ ;

O ₂ →O ₂ ⁺ +e ^−*

N ₂ →N ₂ ⁺ +e ^−*

N ₂ →N+N ⁺ +e ⁻

O ₂ →O+O ⁺ +e ⁻

N+e ^−* →N ^* +e ⁻

O+e ^- →O ^-

O ⁺ +N ^* → O+N ⁺

Embodiment 1: As shown in Figure 1, a bauxite organic matter removal device includes: a control device 1, a grinding and screening device 2, a bauxite silo 3, a feeding device 4, and a micro-plasma corona discharge system 5 , Organic matter processing chamber 6, discharging device 7, bauxite silo 8 after treatment.

The control device 1 includes a grinding and screening device 2 , a bauxite silo 3 , a feeding device 4 , a micro-plasma corona discharge system 5 , an organic matter processing chamber 6 , a discharging device 7 , and a treated bauxite silo 8 .

The grinding and screening device 2 is connected to the bauxite silo 3, the bauxite silo 3 is connected to the feeding device 4, the feeding device 4 is connected to the organic matter treatment chamber 6, the corona discharge device 5 is connected to the organic matter treatment chamber 6, and the organic matter treatment chamber 6 is connected to the The feeding device 7 and the discharging device 7 are connected to the processed bauxite silo 8, and the processed bauxite entering the processed bauxite silo 8 is sent to the Bayer process alumina production process for alumina production.

As shown in Fig. 3 and Fig. 4, the apparatus for treating bauxite organic matter by atmospheric micro-plasma corona discharge includes: bauxite baffle 9, shell 10, feeding port 11, bauxite height control board 12, discharge power supply 13. Multiphase electrode 14, uniform distribution plate 15, crawler-type reaction bed 16, discharge baffle 17, discharge port 18, storage tank 19, ground electrode 20.

Embodiment 2: As shown in Figure 2, the bauxite organic matter removal device includes: a control device 1, a grinding and screening device 2, a bauxite silo 3, a feeding device 4, a micro-plasma corona discharge system 5, organic matter Processing chamber 6 , discharging device 7 , bauxite bin 8 after processing.

The grinding and screening device 2 is connected to the bauxite silo 3, the bauxite silo 3 is connected to the feeding device 4, the feeding device 4 is connected to the organic matter processing chamber 6, the micro-plasma corona discharge system 5 is connected to the organic matter processing chamber 6, and the organic matter processing chamber 6. The discharging device 7 is connected, and the discharging device 7 is connected to the treated bauxite silo 8, and the treated bauxite entering the treated bauxite silo 8 is sent to the Bayer process alumina production process for alumina production.

As shown in FIG. 5 and FIG. 6 , another apparatus for treating bauxite organic matter by atmospheric micro-plasma corona discharge includes: a casing 10 , a feeding port 11 , a discharge power source 13 , a multi-phase electrode 14 , and a uniform distribution plate 15 , discharge port 18, ground electrode 20, stirrer 21.

Figure 3, Figure 4: the housing 10 is used to protect the atmospheric micro-plasma corona discharge treatment bauxite organic matter device, and is made of stainless steel or alloy steel or carbon steel;

The feeding port 11 receives the bauxite sent by the feeding device 4 and sends it to the crawler-type treatment bed 16 provided in the organic matter treatment chamber 6;

The feeding baffle 9 ensures that the bauxite is on the crawler and moves with the movement of the crawler, and is made of refractory plate;

The bauxite height control plate 12 controls the bauxite height on the crawler, and is made of refractory material plate;

The multi-phase electrodes 14 are distributed around the cavity of the organic matter processing chamber 6, and the number of phases is between 2 and 300. The multi-phase electrodes are made of nickel-chromium wire or stainless steel wire, with a diameter of φ1 to 5 mm and a length of 5 to 100 mm. between; the crawler-type reaction bed 16 is connected to the ground electrode 20;

The organic matter processing chamber 6 ensures the formation of uniform corona discharge atmospheric micro-plasma in the chamber. The chamber is provided with a micro-plasma uniform distribution plate 15 and a crawler-type reaction bed 16. The size of the chamber is (600-30000) mm×(600 ～20000)mm×(600～400000)mm, the cavity wall is made of stainless steel or alloy steel or carbon steel;

The discharge power supply 13 provides high-frequency high-voltage current, the power is 50W-300kW, the frequency is 10Hz-6GHz, and the voltage is 1.0KV-70KV;

The shown crawler-type aluminum reaction bed 16 moves at a certain speed, and the bauxite on it undergoes atmospheric micro-plasma corona discharge reaction during the traveling process. A discharge baffle 17 is set at the material port to ensure the discharge direction; the width of the crawler-type aluminum reaction bed 16 is (500-2000) mm, and the length is (2000-380,000) mm; the crawler is made of stainless steel or Teflon; the crawler moving speed is 0.1 ～20m/min; bauxite treatment time is 1～600min; bauxite temperature is 100～150℃ when discharging;

5, as shown in FIG. 6: the housing 10 is used to protect the apparatus for treating bauxite organic matter by atmospheric micro-plasma corona discharge, and is made of stainless steel or alloy steel or carbon steel;

The feeding port 11 receives the bauxite sent by the feeding device 4 and sends it into the organic matter processing chamber 6;

The multi-phase electrodes 14 are distributed around the cavity of the organic matter processing chamber 6, and the number of phases is between 2 and 300. The multi-phase electrodes are made of nickel-chromium wire or stainless steel wire, with a diameter of φ1 to 5 mm and a length of 3 to 100 mm. between;

The organic matter processing chamber 6 ensures that uniform corona discharge atmospheric micro-plasma is formed in the chamber, the chamber is provided with a micro-plasma uniform distribution plate 15 and a stirrer 21, and the phase number of the multi-phase electrode 16 is between 2 and 300; Body size (200～10000)mm×(200～10000)mm×(200～10000)mm, the material of the cavity wall is stainless steel or carbon steel or alloy steel, the stirrer 16 is connected to the ground electrode 20, and the material of the cavity wall is made of stainless steel or carbon steel or alloy steel. Stainless steel or alloy steel or carbon steel;

The bauxite collides with the corona discharge atmospheric micro-plasma in the organic matter treatment chamber 6 and reacts. During the treatment process, the agitator 21 rotates and stirs the bauxite particles to ensure the rapid and uniform reaction of the micro-plasma; The soil ore is pushed into the discharge device 7 through the discharge port 18;

The rotation speed of the agitator 21 is 1-1000r/min, the bauxite treatment time is 1-600min; the bauxite temperature is 100-150°C when discharging; the power of the agitator 21 is 1.1-30KW, and the rotating speed is 1-1000r/min;

The discharging device 6 adopts a bucket conveyor or a screw conveyor to output bauxite, and the bucket conveyor or screw conveyor is provided with a protective cover; The processing capacity is 30~500t/h, the moving speed is 0.15~0.30m/s, and the power is 1.5~75kW; the screw conveyor adopts the GX series or LS series screw conveyor such as China Mining Heavy Equipment, and the hourly processing capacity is 9~150t/h, The rotating speed is 13～112r/min, and the power is 1.1～55kW; after being processed by the discharging device, the bauxite enters the treated bauxite silo; after the discharging device, the treated bauxite enters the treated bauxite silo;

The control device 1 is controlled by PLC or expert system to ensure accurate control and coordination of each program in the processing process, and the opening and closing of each link is coordinated by the program of the control device. PLC control adopts Omron NX7 controller series or NX1 controller series or NX1P controller series or NJ controller series or industrial PC platform NY series or NX series I/O unit; the expert control system is controlled by the expert control system such as Emerson Ovation .

Example 1

Through the control device 1, the grinding and screening device 2, the bauxite silo 3, the feeding device 4, the micro-plasma corona discharge system 5, the organic matter treatment chamber 6, the discharging device 7, and the treated bauxite are started in sequence by PLC control. Mine 8. The control device 1 controls the front and back coordination of the entire atmospheric micro-plasma corona discharge treatment device for bauxite organic matter and the smooth operation of production.

Start the grinding and screening device 2 through the control device 1, grind and sieve it into 40-70 mesh and then send it to the bauxite silo 3. The output of the grinding and screening device is 20t/h, and the bauxite particle size is 40-40 when discharging. 100 mesh and sent to bauxite silo 3;

The feeding device 4 feeds the bauxite in the bauxite silo 3 into the crawler-type aluminum reaction bed 16 in the organic matter processing chamber 6 through the feeding port 11. The bauxite baffle plate 9 and the bauxite height control plate 12 Ensure that the bauxite deposit layer has the same height along the moving direction of the crawler. The height of the bauxite layer on the crawler is 210mm, the width is controlled at 4000mm, the length of the crawler is 24 meters, the moving speed of the bauxite layer is 0.4m/min, and the crawler is lined with stainless steel. Made of high alumina refractory material;

The atmospheric micro-plasma corona discharge device 5 is activated, and a micro-plasma corona discharge area is formed in the organic matter processing chamber 6 through the atmospheric micro-plasma uniform distribution plate 15 between the multi-phase electrode 14 and the ground electrode 20 . The maximum power of the discharge power supply 13 is controlled at 30KW, the frequency is controlled at 27.12KHz, the voltage is 10KV, and the multiphase electrode 14 has 100 phases;

The control device 1 controls the micro-plasma corona discharge system 5 to increase the power proportionally with the increase of the amount of bauxite. When the crawler-type bauxite treatment bed 16 reaches full load, the power is added to 30KW, and then the power is controlled according to the temperature of the bauxite. Adjust the power of the discharge power supply; during the bauxite treatment process, the temperature is controlled every 3 meters on the length of the crawler (8 in total). 120℃, 120℃, 150℃; bauxite discharge temperature is 150℃;

After the treatment is completed, the bauxite enters the storage tank 19 through the discharge port 18 at the discharge end of the crawler-type bauxite treatment bed 16, and the discharge baffle 17 ensures the discharge direction; the storage tank 19 is connected to the discharge device 7 and the aluminum The soil ore is sent to the treated bauxite silo 8 for use;

Table 1 is the chemical composition analysis of the bauxite in Example 1 before and after the atmospheric micro-plasma corona discharge treatment. The analysis results show that the organic matter content of the original bauxite ore is 0.278%wt. Before and after the atmospheric microplasma corona discharge treatment, the organic matter content in the bauxite is 0.105%wt, a decrease of 62.20%, which has reached the use of bauxite organic matter. standard.

Table 1 Comparison of chemical components of bauxite treated in Example 1

Fig. 7 XRD analysis results show that the main constituent phases of each component in the bauxite ore are gibbsite, boehmite, kaolinite, anatase, hematite, trypanite and organic matter.

in:

Gibbsite (PDF#70-2038) corresponds to 22 peaks, which are 18.362°, 20.379°, 20.628°, 26.594°, 28.09°, 36.486°, 36.695°, 37.162°, 39.393°, 41.769°, 44.246° , 45.519°, 47.385°, 50.627°, 52.254°, 63.878°, 66.277°, 66.727°, 68.961°, 72.759°, 77.508°, 79.303°;

Boehmite (PDF#21-1307) corresponds to 5 peaks, which are 14.585°, 28.281°, 38.436°, 49.311°,

Kaolinite PDF#75-1593 corresponds to 9 peaks, which are 19.89°, 35.46°, 40.36°, 41.6°, 45.46°, 49.43°, 49.63°, 54.35°, 57.87°;

Anatase (PDF#21-1272) corresponds to 5 peaks, which are 25.366°, 53.95°, 62.179°, 62.748°, 70.369°,

Hematite (PDF#33-0664) corresponds to 5 peaks, 40.914°, 54.149°, 56.21°, 62.509°, 71.995°;

Conestone (PDF#17-0470) corresponds to 3 peaks, 32.897°, 58.133°, 71.671°;

In addition, there are a large number of organic matter peaks 12.405°, 21.273°, 24.45°, 24.88°, 24.92°, 33.278°, 35.307°, 47.594°, 50.597°, 55.467°, 58.618°.

Figure 7 XRD analysis results show that the main phase composition of the treated bauxite is gibbsite, boehmite, kaolinite, anatase, hematite, carbide hydroxy iron, and trypanite.

Among them, gibbsite (PDF#70-2038) corresponds to 19 peaks, which are 18.367°, 20.602°, 26.564°, 26.946°, 36.434°, 37.712°, 41.8°, 44.193°, 49.361°, 52.195°, 54.433 °, 63.785°, 66.443°, 68.852°, 69.447°, 75.985°, 76.147°, 77.256°, 77.69°;

Boehmite (PDF#21-1307) corresponds to 5 peaks, which are 14.585°, 28.281°, 38.436°, 49.311°;

Kaolinite (PDF#78-2110) corresponds to 11 peaks, which are 12.447°, 33.077°, 41.672°, 45.44°, 47.307°, 50.532°, 54.689°, 57.589°, 62.538°, 66.184°, 66.792°;

Anatase (PDF#73-1764) corresponds to 4 peaks, respectively 25.367°, 37.908°, 54.05°, 62.278°;

Hematite (DF#85-0987) corresponds to 4 peaks, which are: 33.211°, 35.728°, 39.319°, 72.032°;

The cone stone (PDF#17-0470) corresponds to 5 peaks, which are 18.505°, 24.975°, 27.966°, 36.66°, 50.725°;

Iron hydroxycarbide (PDF#84-0283) corresponds to 15 peaks, which are 12.203°, 12.347°, 20.355°, 24.737°, 24.737°, 25.289°, 33.5°, 33.616°, 39.491°, 40.113°, 44.064°, 44.304°, 45.544°, 45.793°, 47.361°;

XRD analysis of bauxite minerals before and after micro-plasma treatment found that there was almost no change after micro-plasma treatment, the crystal form of kaolinite, anatase, and hematite changed, the organic matter peak disappeared, and new compounds appeared Hydroxy iron carbide. Combined with the results in Table 1, it shows that after the atmospheric micro-plasma corona discharge treatment, the organic matter content is greatly reduced and has reached an undetectable level. The new compound ferric carbide should be the product of decarburization from organic matter, which has been used for bauxite. Mineral dissolution has no effect.

Embodiment 2

Start the grinding and screening device 2 through the control device 1, grind and sieve it into 40-70 meshes and then send it to the bauxite silo 3. The hourly output of the grinding and screening device is 5t/h, and the bauxite particle size when discharging is 40-70 mesh. 100 mesh and sent to bauxite silo 3;

The feeding device 4 sends the bauxite in the bauxite silo 3 into the organic matter processing chamber 6 through the feeding port 11;

The atmospheric plasma corona discharge device 5 is activated, and a micro-plasma corona discharge area is formed in the organic matter processing chamber 6 through the atmospheric micro-plasma uniform distribution plate 15 between the multi-phase electrode 14 and the ground electrode 20 . In the atmospheric plasma corona discharge device 5, the maximum power of the discharge power supply 13 is controlled at 20KW, the frequency is controlled at 2.45GHz, the voltage is 4KV, and the multiphase electrodes 14 have 40 phases;

The feeding device 4 feeds the bauxite in the bauxite silo 3 into the organic matter treatment chamber 6 through the feeding port 11, and starts the agitator 21 when the amount of bauxite added reaches 10% vol of the organic matter treatment chamber. The atmospheric plasma corona discharge device 5 is started, and the atmospheric micro-plasma corona discharge is formed in the organic matter processing chamber 6 through the atmospheric micro-plasma uniform distribution plate 15 between the multi-phase electrode 14 and the ground electrode 20, and the rotation speed of the agitator 21 is 10r /min;

The power of the micro-plasma corona discharge system 5 increases proportionally with the increase in the amount of bauxite added. When the bauxite in the organic matter treatment chamber 6 reaches 2/3vol (5t, the size of the bauxite cavity is φ2500mm×1500mm), the power increases. When the temperature reaches 20KW, the bauxite temperature is controlled by the control device 1, and the maximum temperature shall not exceed 150°C; the processing time is 120min; the bauxite discharge temperature is 140°C; Push the bauxite into the discharging device 6 and enter the treated silo 7 for use.

Table 2 is the composition comparison of raw bauxite ore and bauxite of Example 2 after being treated by atmospheric micro-plasma corona discharge. The results show that the organic matter content in the raw bauxite ore is 0.501% wt, and it becomes 0.150% wt after the atmospheric micro-plasma corona discharge treatment, a decrease of 70.00%, which has reached the standard for the use of bauxite organic matter.

Table 2 Comparison of chemical composition of bauxite before and after micro-plasma treatment

Figure 8 shows the XRD analysis results, the main phase composition in the bauxite ore of Example 2 is gibbsite, boehmite, tricalcium aluminate, nickel titanate, gallium, GaO ₂ H, hematite , spinel and organic tetraphenyl phosphine permanganate and p-nitrophenol.

Among them, gibbsite (PDF#70-2038) occupies 39 peaks, which are 18.347°, 20.582°, 21.779°, 28.039°, 30.303°, 31.694°, 32.816°, 33.132°, 36.631°, 38.336°, 39.321°, 40.183°, 40.242°, 41.127°, 41.231°, 44.256°, 44.753°, 45.603°, 46.192°, 50.076°, 52.344°, 54.413°, 54.57°, 55.406°, 56.484°, 58.07° , 60.015°, 61.788°, 62.489°, 62.931°, 66.423°, 66.771°, 67.909°, 71.556°, 77.38°, 78.623°, 79.13°, 79.409°, 79.519°;

Hematite has two crystal forms, among which hematite (PDF#85-0987) has 7 peaks, which are 24.22°, 33.231°, 35.748°, 40.976°, 62.616°, 64.209°, 79.031°; hematite Mine (PDF#86-0550) (α-Fe ₂ O ₃ ) has 5 peaks, which are 49.503°, 57.647°, 72°, 77.78°, 78.813°;

Jia (PDF#31-0540) has a peak of 71.838°;

Potassium oxyhydride GaO ₂ H (PDF#06-0180) has 11 peaks, which are 21.417°, 35.204°, 36.589°, 37.156°, 40.659°, 51.192°, 53.929°, 59.921°, 63.969°, 68.937°, 72.613°;

Tricalcium aluminate (PDF#32-0148) has 18 peaks at 12.875°, 21.014°, 25.516°, 26.627°, 30.251°, 37.057°, 37.85°, 39.636°, 47.436°, 47.834°, 48.049° , 50.373°, 58.19°, 58.936°, 59.513°, 62.184°, 64.697°, 68.27°;

Spinel (PDF#47-0254) has 11 peaks, which are 20.49°, 28.76°, 32.299°, 33.895°, 35.925°, 41.363°, 46.108°, 66.238°, 67.019°, 69.264°, 76.205°;

Nickel titanate (PDF#33-0960) has 5 peaks, which are 24.151°, 41.899°, 56.226°, 64.088°, 75.127°;

Organic matter p-hydroxynitrophenol (PDF#50-2237) and tetraphenylphosphine permanganate (PDF#24-1874) peaks 12.553°, 14.706°, 17.793°, 18.793°, 25.3°, 27.079°, 33.645°, 49.765°, 54.127°, 14.467°, 25.308°.

Figure 8 shows the XRD analysis results, the main phase compositions in the treated bauxite are gibbsite, hematite, gallium, gallium oxyhydride GaO ₂ H, tricalcium aluminate, spinel, and nickel titanate. in:

Gibbsite occupies 39 peaks, 18.347°, 20.338°, 20.582°, 26.544°, 26.926°, 28.039°, 28.759°, 33.847°, 35.189°, 35.841°, 36.414°, 36.631°, 37.099°, 37.692° , 38.336°, 40.126°, 41.78°, 43.391°, 43.696°, 44.173°, 45.896°, 46.192°, 47.395°, 49.228°, 50.532°, 52.175°, 52.674°, 54.413°, 55.406°, 55.847° °, 58.581°, 62.931°, 63.765°, 67.503°, 67.909°, 68.832°, 69.427°, 79.13°;

There are two crystal forms of hematite, of which hematite (PDF#85-0987) has 8 peaks, which are 33.231°, 35.748°, 39.339°, 49.594°, 64.209°, 66.212°, 75.707°, 79.031°; Hematite (PDF#86-0550) (α-Fe2O3) has 2 peaks, 43.547° and 57.647° respectively;

Jia (PDF#31-0540) has three peaks, 40.46°, 45.539°, 62.54°;

Gallium oxyhydride GaO ₂ H (PDF#06-0180) has 10 peaks at 17.992°, 21.417°, 33.619°, 37.156°, 37.156°, 45.704°, 51.192°, 53.929°, 58.174°, 62.384°, 65.022 °, 66.701°, 67.799°, 68.937°;

Tricalcium aluminate (PDF#32-0148) has 18 peaks at 20.086°, 21.014°, 23.466°, 25.516°, 33.228°, 35.597°, 37.85°, 38.852°, 39.636°, 44.507°, 48.049° , 50.788°, 55.345°, 55.776°, 59.094°, 59.513°, 62.017°, 69.824°;

Spinel (PDF#47-0254) has 11 peaks, which are 17.624°, 27.234°, 33.895°, 38.253°, 41.363°, 41.705°, 53.571°, 56.114°, 64.647°, 67.019°, 76.205°;

Nickel titanate (PDF#33-0960) has 6 peaks, which are 24.151°, 33.109°, 40.874°, 49.468°, 54.037°, 78.871°, respectively.

Comparative Example 2 The XRD phase composition and peak value of bauxite before and after treatment by atmospheric micro-plasma corona discharge were found. The two crystal forms of the ore are converted to each other, the hematite (PDF#85-0987) has one more peak, and the hematite (PDF#86-0550) (α-Fe ₂ O ₃ ) has been reduced from 5 peaks to 2 The peaks, Ga has changed from one peak to three peaks, and gallium oxyhydrogen GaO ₂ H has one less peak, indicating that after the micro-plasma treatment, while reducing the organic matter, the phase and crystal form also changes, Ga and GaO ₂ H and increased activity.

According to the results of Example 1 and Example 2, it is found that the use of atmospheric micro-plasma corona discharge to treat bauxite can reduce the organic matter content in bauxite to 0.1～0.15%wt, the organic content decreased by 60～75%wt. It greatly reduces the influence of organic matter on the dissolution performance of the bauxite dissolution process, and is a simple and effective method for directly solving the bauxite organic matter from the source.

In the description of this specification, description with reference to the terms "an embodiment," "some embodiments," etc. means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example. In this specification, schematic representations of the above terms are not necessarily directed to the same embodiment or example. Furthermore, the particular features, structures, materials or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, those skilled in the art may combine and combine the different embodiments or examples described in this specification, as well as the features of the different embodiments or examples, without conflicting each other.

Although the embodiments of the present invention have been shown and described above, it should be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Embodiments are subject to variations, modifications, substitutions and variations.

Claims

A method for removing organic matter from bauxite, which is characterized by comprising the following contents:

(1) Grinding and sieving the bauxite into 40-100 mesh particles;

(2) Send the screened bauxite into the organic matter treatment chamber; the organic matter treatment chamber includes a cavity, and a crawler-type bauxite treatment bed or agitator is arranged in the cavity; the crawler-type bauxite treatment bed makes the bauxite ore It moves with the crawler during the reaction, and enters the discharge device with the crawler after the reaction; the agitator stirs the bauxite while the micro-plasma reaction occurs, ensuring a fast and uniform reaction and facilitating the bauxite discharge;

(3) Start the micro-plasma corona discharge system, and input electromagnetic energy into the organic matter treatment chamber through the multi-phase electrode, so that the air in the organic matter treatment chamber is ionized to generate micro-plasma, and electrons and high-energy particles in the micro-plasma are combined with bauxite. The powder undergoes continuous collision and bombardment. Due to the low dissociation energy of C-H bonds in organic matter, hydrogen and active groups are dissociated. These electrons, hydrogen, high-energy particles and active groups continue to undergo excitation, ionization, recombination and three-body recombination. Reaction to achieve indiscriminate dissociation or oxidation of organic matter in bauxite, so as to eliminate organic matter in bauxite without affecting other components in bauxite;

(4) After the treatment, the bauxite temperature is 100-150° C., and the organic matter in the bauxite is dissociated and oxidized into CO 2 , CO, H 2 O and N 2 .
A bauxite organic matter removal device for the bauxite organic matter removal method according to claim 1, characterized in that it comprises: a grinding vibration screening device, a bauxite silo, a feeding device, a micro-plasma electric Corona discharge system, organic matter treatment chamber, discharge device, treated bauxite silo, control device; control device controls grinding and vibrating screening device, feeding device, micro-plasma corona discharge system, organic matter treatment chamber, and discharging device ;The grinding and vibrating screening device is connected to the bauxite silo, the bauxite silo is connected to the feeding device, the feeding device is connected to the organic matter treatment chamber, the micro-plasma corona discharge system is connected to the organic matter treatment chamber, and the organic matter treatment chamber is connected to the discharge device. The feeding device is connected to the treated bauxite silo; the treated bauxite silo is connected to the Bayer process alumina production facility; the organic processing cavity includes a cavity, and a crawler-type bauxite treatment bed or agitator is arranged in the cavity; the agitator The rotation speed is 1-1000 r/min; the grinding and vibrating screening device grinds and sieves the bauxite, and the vibration frequency is 6-700 times/min and the amplitude is 2-50 mm during the vibrating grinding and screening; the micro-plasma The body corona discharge system includes a discharge power source, a multi-phase electrode and a ground electrode; the discharge power source generates a high-frequency high-voltage current with a power of 50W to 300kW, a frequency of 10Hz to 6GHz, and a voltage of 1.0KV to 70KV. Corona discharge atmospheric micro-plasma; the distance between the multi-phase electrode and the ground electrode is 0.1-200mm, and the generated atmospheric micro-plasma is guaranteed to be in full contact with bauxite particles.
A method for removing organic matter from bauxite, which is characterized by comprising the following contents:

(1) Grinding and sieving the bauxite into 40-100 mesh particles;

(2) Send the screened bauxite into the organic matter treatment chamber; the organic matter treatment chamber includes a cavity, and a crawler-type bauxite treatment bed or agitator is arranged in the cavity; the crawler-type bauxite treatment bed makes the bauxite ore It moves with the crawler during the reaction, and enters the discharge device with the crawler after the reaction; the agitator stirs the bauxite while the micro-plasma reaction occurs, ensuring a fast and uniform reaction and facilitating the bauxite discharge;

(3) Start the micro-plasma corona discharge system, and input electromagnetic energy into the organic matter treatment chamber through the multi-phase electrode, so that the air in the organic matter treatment chamber is ionized to generate micro-plasma, and electrons and high-energy particles in the micro-plasma are combined with bauxite. The powder undergoes continuous collision and bombardment. Due to the low dissociation energy of C-H bonds in organic matter, hydrogen and active groups are dissociated. These electrons, hydrogen, high-energy particles and active groups continue to undergo excitation, ionization, recombination and three-body recombination. Reaction to achieve indiscriminate dissociation or oxidation of organic matter in bauxite, so as to eliminate organic matter in bauxite without affecting other components in bauxite;

(4) After the treatment, the bauxite temperature is 100-150° C., and the organic matter in the bauxite is dissociated and oxidized into CO 2 , CO, H 2 O and N 2 .
A bauxite organic matter removal device for the bauxite organic matter removal method according to claim 1, characterized in that it comprises: a grinding vibration screening device, a bauxite silo, a feeding device, a micro-plasma electric Corona discharge system, organic matter treatment chamber, discharge device, treated bauxite silo, control device; control device controls grinding and vibrating screening device, feeding device, micro-plasma corona discharge system, organic matter treatment chamber, and discharging device ;The grinding and vibrating screening device is connected to the bauxite silo, the bauxite silo is connected to the feeding device, the feeding device is connected to the organic matter treatment chamber, the micro-plasma corona discharge system is connected to the organic matter treatment chamber, and the organic matter treatment chamber is connected to the discharge device. The feeding device is connected to the treated bauxite silo; the treated bauxite silo is connected to the Bayer process alumina production facility; the organic processing cavity includes a cavity, and a crawler-type bauxite treatment bed or agitator is arranged in the cavity; the agitator The rotation speed is 1-1000 r/min; the grinding and vibrating screening device grinds and sieves the bauxite, and the vibration frequency is 6-700 times/min and the amplitude is 2-50 mm during the vibrating grinding and screening; the micro-plasma The body corona discharge system includes a discharge power source, a multi-phase electrode and a ground electrode; the discharge power source generates a high-frequency high-voltage current with a power of 50W to 300kW, a frequency of 10Hz to 6GHz, and a voltage of 1.0KV to 70KV. Corona discharge atmospheric micro-plasma; the distance between the multi-phase electrode and the ground electrode is 0.1-200mm, and the generated atmospheric micro-plasma is guaranteed to be in full contact with bauxite particles.