WO2022095263A1

WO2022095263A1 - Red mud comprehensive utilization method and device

Info

Publication number: WO2022095263A1
Application number: PCT/CN2020/141326
Authority: WO
Inventors: 刘春莲; 王晧; 段小刚
Original assignee: 太原理工大学
Priority date: 2020-11-06
Filing date: 2021-02-17
Publication date: 2022-05-12
Also published as: CN112547753A; CN112547753B

Abstract

A red mud comprehensive utilization method and device. The red mud comprehensive utilization device comprises a red mud pretreatment device (2), a red mud drying bin (3), a feeding device (4), an atmospheric micro-plasma discharge device (5), a red mud treatment cavity (6), a gas recovery device (9), a discharging device (7), a waste heat recovery device (11), a grinding and screening device (8), a treated red mud bin (10), and a control device (1). The red mud comprehensive utilization method comprises: pretreating red mud, and performing evaporation to remove moisture and then grinding; feeding the red mud into the red mud treatment cavity (6); and starting the atmospheric micro-plasma discharge device (5), inputting electromagnetic energy into the red mud treatment cavity (6) via a multi-phase electrode (17) by means of a discharge power source (16), enabling the treated red mud to enter an ore dressing device from the treated red mud bin, and respectively separating out iron and titanium from the red mud, and using the remaining part as a refractory material raw material. The impact excitation bombardment effect of electrons and active particles generated by atmospheric micro-plasma discharge is utilized, and a composite oxide is dissociated into a relatively simple oxide which is easy to separate, thereby providing convenience for subsequent ore dressing; the method is rapid and efficient.

Description

Method and device for comprehensive utilization of red mud

technical field

The invention relates to the field of metallurgical solid waste and reuse, in particular to a method and a device for comprehensive utilization of red mud.

Background technique

In 2019 alone, the world's alumina output was 162.3 million tons, and my country's output accounted for 44.6% of it. Red mud is an emission in alumina industrial production. The average particle size of red mud is less than 10 μm, and the pH value is 12-14, which has strong corrosion. The emission is about 1 to 1.5 times that of alumina production, and the huge amount of red mud has become a major public nuisance. .

At present, the processing method of red mud by alumina production enterprises is mainly red mud storage. The red mud storage will be constructed simultaneously when the aluminum plant is started. The construction cost of 300,000 tons of red mud storage is as high as 42 million RMB. Occupying a lot of land, the cost is huge, and the daily maintenance cost is tens of millions, and the alumina production enterprises are overwhelmed. Once the red mud silo leaks, it will pollute the surrounding farmland, causing serious heavy metals in the soil to exceed the standard, and even alumina production enterprises will stop production due to environmental protection problems in the red mud silo.

Countries all over the world attach great importance to the research of red mud. There are dozens of methods for the harmless treatment and reuse of red mud, mainly focusing on calcining harmless treatment, building and structural materials, cement, ceramic materials, etc. Due to cost and processing capacity constraints, it is difficult to promote it on a large scale.

SUMMARY OF THE INVENTION

The invention aims to generate atmospheric micro-plasma at atmospheric pressure through the principle of micro-plasma discharge, and utilizes electrons, active particles and free radicals in the plasma to collide, excite, crack and recombine with red mud particles to dissociate and transform complex oxides in red mud into red mud particles. into relatively simple oxides. After the reaction, the gas is recovered as fuel gas, and sodium is volatilized in the form of oxide at high temperature and discharged with the gas. The remaining oxides are used in beneficiation to produce high-grade iron ore powder, titanium ore powder, refractory materials, and cement raw materials, turning waste into treasure, and realizing the comprehensive utilization of red mud at a low cost.

A method for comprehensive utilization of red mud, comprising the following steps:

1. The red mud is pretreated, evaporated to remove water, and then ground. Red mud particles require 70 to 200 mesh, moisture ≤ 5%;

2. Send the red mud into the red mud treatment chamber;

3. Start the atmospheric micro-plasma discharge device, and input the electromagnetic energy into the red mud treatment chamber through the multi-phase electrode by using the discharge power supply, so that the atmosphere in the red mud treatment chamber is ionized to generate electrons and high-energy charged particles, and the electrons and high-energy charged particles are related to the environment. The red mud particles are continuously collided and bombarded, excited to generate a large number of electrons, high-energy particles, free radicals, metastable red mud particles and charged red mud particles and undergo ionization, recombination and three-body recombination reactions, so that the temperature of red mud rapidly increases to 600 ～1300℃, the complex oxides in the red mud particles are rapidly cracked;

3-1. Preferably, the red mud treatment chamber includes a cavity, and a stirrer is installed in the cavity to stir the red mud while the micro-plasma reaction occurs, so as to ensure the rapid and uniform plasma reaction and facilitate the discharge of the red mud;

3-2. Preferably, or a belt-type red mud treatment bed is arranged in the red mud treatment chamber, the red mud moves with the crawler while the micro-plasma reaction occurs, and the red mud enters the discharge device with the crawler after the reaction;

4. After the reaction, the hematite and other complex Na-Al-Si-Ti and other oxides in the red mud become magnetite, TiO ₂ series, Al ₂ O ₃ ·SiO after the cracking reaction according to the different red mud components. ₂ series, CaO·TiO ₂ series and gas Na ₂ O, CO ₂ , CO, H ₂ , free H ₂ O;

5. The mixed gas of Na ₂ O, CO ₂ , CO, H ₂ and free H ₂ O is collected by venturi for dust removal. The gas of Na ₂ O, CO ₂ and free H 2 O is dissolved in water, and the mixed gas of CO and H ₂ is recovered as Gas or used for red mud pretreatment as fuel;

6. After the treatment is completed, the red mud is discharged. The temperature of the red mud is 600-1300 °C during discharge. The residual heat of the red mud is recovered by the waste heat recovery device and then sent to the red mud pretreatment device for drying the red mud;

7. When the temperature of red mud drops to 100～200℃, the red mud enters the grinding and screening device, and the red mud is screened and ground into 0.074～4mm particles and sent to the treated red mud silo;

8. The treated red mud enters the beneficiation device from the treated red mud silo, and successively separates iron and titanium from the red mud into high-grade iron ore powder by means of gravity separation, gradient magnetic separation, flotation, pickling, electric separation, etc. and high-grade titanium ore powder, and the remaining part is used as refractory raw material.

9. 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, the voltage, frequency, power and phase difference of the discharge power supply are adjusted to generate uniform atmospheric micro-plasma discharge in the red mud treatment chamber, and electrons and charged particles continue to collide and bombard the red mud particles to further generate a large number of electrons. and high-energy particles, the electron density of this microplasma is very high, which can reach 10 ¹⁶ cm ^-3 , which can almost reach the level of arc discharge. A large number of moving electrons and high-energy particles collide with each other and are excited to produce more high-energy electrons, charged particles, Excited particles and metastable particles, such as:

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 ⁺

The above high-energy electrons, charged particles, excited particles and metastable particles collide with red mud particles, and the electrons in the red mud particles are excited to become positively charged particles or absorb electron energy to become metastable particles or capture electrons to form bands Negatively charged particles, they continue to collide and bombard each other, the CH bond, OO bond, OH bond, CO bond, Fe-O bond and some complex bonds in the composite compound in the red mud absorb a lot of electron energy and high-energy particle energy. Activation, electron capture and ionization. According to the difference of the bond dissociation energy, the CH bond, OH bond, Fe-O, Na-O bond with lower bond dissociation energy dissociates, so that the complex oxide is dissociated into Fe ₃ O ₄ and Al ₂ O ₃ which are relatively simple and easy to separate. · SiO ₂ etc., CaO·TiO ₂ , TiO ₂ and gases Na ₂ O, CO ₂ , CO, H ₂ . At the same time, due to the bombardment and dissociation reaction of a large number of electrons and various ions, the temperature of red mud has increased to 600-1300 ° C. During the volatilization process of Na at high temperature, Na 2 O is reacted to form Na ₂ O which is discharged with the flue gas, and is recovered and processed by a recovery device. After the reaction, the red mud is subjected to the next step of beneficiation treatment.

A red mud comprehensive utilization device, comprising: a red mud pretreatment device, a drying red mud silo, a feeding device, an atmospheric micro-plasma discharge device, a red mud treatment chamber, a gas recovery device, a discharging device, a waste heat recovery device, Grinding and screening device, treated red mud silo, control device;

The control device controls the red mud pretreatment device, drying red mud silo, feeding device, atmospheric micro-plasma discharge device, red mud treatment chamber, gas recovery device, discharge device, waste heat recovery device, grinding and screening device, after treatment red mud silo;

The red mud pretreatment device is connected to the drying red mud silo, the drying red mud silo is connected to the feeding device, the feeding device is connected to the red mud treatment chamber, the atmospheric micro-plasma discharge device is connected to the red mud treatment chamber, and the red mud treatment chamber is connected to the discharge Device and gas recovery device, discharge device is connected to grinding and screening device, discharge device is connected to waste heat recovery device, waste heat recovery device is connected to red mud pretreatment device, discharge device is connected to grinding and screening device, grinding and screening device Red mud silo after connection processing;

The red mud pretreatment device is used for evaporating the water in the red mud, and can be treated by the hot air heating method, and the residual heat of the red mud after the treatment is used as an auxiliary. In the dry red mud silo. The red mud pretreatment temperature is 150～280℃, and the processing time is 60min～600min; after drying, the red mud moisture is less than 5%, and the red mud particles are 70～200 mesh; after discharging, the red mud is put into the red mud silo;

The feeding device uses a super-dense phase conveying device or vacuum feeding to convey the red mud to the atmospheric micro-plasma red mud treatment device;

The super-dense phase feeding is to convert the red mud bed through fluidization operation into a "gas-solid two-phase" fluid. In this way, the potential energy of the red mud in the drying red mud silo is transferred to the flow direction through this "gas-solid two-phase" fluid, and a pressure gradient is formed, and red mud columns of different heights are formed in each balance column. The red mud column pushes the red mud towards the lower direction of the 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 atmospheric micro-plasma discharge device includes a discharge power source, a multi-phase electrode and a ground electrode; the discharge power source has a power of 50W to 300,000W, a frequency of 10Hz to 6GHz, and a voltage of 1.0KV to 70KV; the multiphase electrode accepts high voltage and maintains a certain distance from the ground electrode. The atmosphere is ionized; the distance between the multi-phase electrode and the ground electrode is between 1.0mm and 300mm;

The red mud treatment chamber receives the red mud sent by the feeding device and ensures that the treated red mud is transported out; an agitator or a crawler-type red mud treatment bed or agitator can be installed in the red mud treatment chamber to ensure that the red mud particles and the Atmospheric micro-plasma is fully contacted and collided, and the reaction is fast and uniform; at the same time, the red mud is pushed to the discharge port after the red mud treatment is completed; After the reaction, it enters the discharging device; the rotation speed of the agitator is 1～1000r/min, the moving speed of the crawler is 0.1～20m/min, the processing time of red mud is 5～600min, and the temperature of red mud during discharging is 600～1300℃;

The gas recovery device utilizes the venturi treatment method to treat the gas generated in the process of red mud treatment, and after gas-water separation, Na ₂ O, CO _{2 and} free H ₂ O form a solution; the remaining CO and H ₂ are recovered as fuel gas ;

The discharge device uses a bucket discharger or a screw conveyor to discharge the material, and the bucket discharger or screw conveyor is provided with a protective cover and a waste heat recovery device to collect high-temperature flue gas and dedust the high-temperature flue gas and then send it to the red mud pre-treatment Drying the red mud by the treatment device;

The waste heat recovery device uses a high-temperature fan to transport the high-temperature flue gas to the red mud preheating device. The conveying pipeline adopts thermal insulation measures to prevent heat loss and noise reduction measures to prevent noise. , dust removal can use electrostatic precipitator;

The grinding and screening device uses a vortex method, a linear method, a jigging method, a rotary method, a swing method or a roller method to grind and screen the red mud, and the vibration frequency is 6 to 700 times per minute during vibration grinding and screening. , the amplitude of 2 ~ 50mm. After grinding and screening, the red mud is put into the treated red mud silo;

The ore dressing device is composed of gravity separation, gradient magnetic separation, flotation, pickling, electric separation and other devices. First, the iron is selected to become high-grade iron ore powder through gravity separation and magnetic separation; The red mud titanium is selected into high-grade titanium ore powder by methods such as electric separation, and the remaining Al ₂ O ₃ ·SiO ₂ series and CaO · Al ₂ O ₃ series are used as refractory materials and cement raw materials.

Further, the red mud pretreatment method is to use circulating hot air to evaporate the water in the red mud on the tunnel type or drum type drying equipment, and the BLH-RFM-04 circulating dryer of Yancheng Bailihao Environmental Protection Machinery Manufacturing Co., Ltd. can be selected. Or the HZG type tumble dryer of Henan Taihang Machinery Equipment Co., Ltd.; the hot air temperature is 600-800℃;

Further, the ultra-dense phase feeding device adopts PECHINEY ultra-dense phase conveying device. The conveying capacity is 10～300t/h; the flow velocity is less than 0.28m/s; the pressure range is 2～8Pa;

Further, the vacuum feeder uses vacuum to suck the red mud into the red mud treatment chamber, such as the ZKS series electric vacuum feeder of Xinxiang Renault Machinery Co., Ltd., with a power of 0.25-30kW and a vacuum degree range of -5 ~-31kPa;

Further, the atmospheric micro-plasma discharge device includes a discharge power supply, a multi-phase electrode and a ground electrode; the micro-plasma generator generates high-frequency high-voltage current, the power is 50W-300kW, the frequency is 10Hz-6GHz, and the voltage is 1.0KV-70KV; The phase electrode undertakes high voltage, the multi-phase electrode is connected with the discharge power supply with wires, and the number of phases is controlled between 2 and 300. The multi-phase electrode is made of nickel-chromium wire or stainless steel wire, with a diameter of 0.5 to 5 mm and a length of 30 ～300mm; and keep a certain distance from the ground electrode, during which the atmosphere is ionized; the distance between the multi-phase electrode and the ground electrode is between 1.0mm and 300mm; the ground electrode can be a cavity wall or a stirrer fan blade;

Further, the red mud processing chamber is used to ensure the formation of uniform atmospheric micro-plasma in the chamber; the multi-phase electrodes of the atmospheric micro-plasma discharge device are evenly distributed outside the red mud processing chamber and extend into the interior of the chamber. Body size (300～30000)mm×(200～30000)mm×(200～400000)mm, the cavity wall is made of stainless steel or carbon steel or alloy steel; red mud treatment cavity wall or agitator or belt type red mud The grounding of the treatment bed becomes the grounding electrode of the atmospheric micro-plasma discharge device, ensuring that the interior of the red mud treatment chamber becomes the atmospheric micro-plasma discharge area; the micro-plasma uniform distribution plate is set up in the red mud treatment chamber close to the multi-phase electrodes to ensure the red mud treatment chamber. A uniform discharge atmospheric micro-plasma is generated in the chamber. The uniform distribution plate of the micro-plasma is an alumina plate or a mullite plate, with a thickness of 3-30mm, and the distance from the multi-phase electrode is 3-30mm; the feed end of the red mud treatment chamber is The drying red mud inlet, the discharge end is the processed red mud outlet, and the gas outlet is set at the top. The gas generated by the micro-plasma reaction enters the flue gas collection device through the gas outlet; the processed red mud directly enters the discharging device from the red mud outlet. ;The outer casing of the red mud treatment chamber is used to protect the multi-phase electrodes. The material of the red mud treatment chamber can be stainless steel, carbon steel or alloy steel, and the distance from the red mud chamber in each direction is set between 200 and 800 mm. ;The atmospheric micro-plasma discharge device can be integrated between the red mud treatment chamber and the shell, or can be arranged separately; the micro-plasma treatment time of red mud is 5-600min; the temperature of red mud is 600-1300℃ when discharging;

Preferably, a stirrer can be installed in the red mud treatment chamber, and the fan blades of the stirrer are grounded. Series mixer or BLD series mixer, power 1.1～30KW;

Preferably, the red mud treatment chamber is provided with a belt-type red mud treatment bed, the red mud moves with the crawler during the micro-plasma reaction, and enters the discharge device with the crawler after the treatment; the red mud treatment bed can be made of medium ore heavy installed mobile belt conveyor series or DSL belt conveyor series or DTL belt conveyor series;

Further, after the gas collection device collects the mixed gas of Na ₂ O, CO ₂ , CO and H ₂ , a venturi processing device can be used for gas-water separation, wherein Na ₂ O and CO ₂ enter the water to form a solution; CO and H ₂ are mixed gas recovery into gas;

Further, the discharging device adopts a bucket conveyor or screw conveyor to output red mud, the bucket conveyor or screw conveyor is provided with a protective cover, and a flue gas device is provided to collect high-temperature flue gas and send it to the red mud pretreatment device. Drying red mud; the bucket 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 waste heat recovery device uses a high-temperature fan to transport the high-temperature flue gas to the red mud preheating device, and the conveying pipeline adopts thermal insulation measures to prevent heat loss and noise reduction measures to prevent noise. Circulating fans, such as the CX series high temperature resistant fans of Gupu environmental protection, Haiquanfeng's RC series axial flow hot air circulator and RB-I series centrifugal hot air circulator;

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 particle size of the red mud under the sieve is 0.074～4mm;

Further, the iron is selected as high-grade iron ore powder through gravity separation and magnetic separation; then titanium in red mud is selected into high-grade titanium ore powder through flotation, pickling, electric separation and other methods, and the remaining part is used as cement. Raw materials or refractory raw materials are used. Gravity separation uses chute separation, jigging separation or shaking table separation in turn. Chute separation of 5LL glass fiber reinforced plastic rotating spiral chute of Ganye Mining Machine; Times 80～180r/min, power 1.5～7.5KW; Shaker selection adopts LY and 6S series shakers produced by Ganye Mining Machine, lateral slope: 0～10°, stroke: 6～30mm, stroke time: 250～450r /min; magnetic separation adopts CTG-7522 dry magnetic separator of Ganye Mining Machine; flotation adopts XFD, XJK5A flotation machine of Jiangxi Ganye; electric separation adopts SJD produced by Shicheng County Yongrui Mining Machinery Factory -II type high voltage electric separator;

Further, PLC control or expert system control is used for the process control 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 control system program. 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 units; the expert control system uses expert control systems, such as Emerson Ovation experts Control System.

practicality

The red mud comprehensive utilization devices of the present invention are all conventional products, and the red mud comprehensive utilization method is practical.

The invention utilizes the collision excitation bombardment effect of electrons and active particles generated by atmospheric micro-plasma discharge to dissociate the composite oxides into relatively simple oxides that can be easily separated, which provides great convenience for subsequent beneficiation, is fast and efficient, and at the same time It saves expensive vacuum equipment and integrates alkali reduction, separation of iron and titanium components, which is a good way to solve the problem of red mud.

Description of drawings

FIG. 1 is a schematic diagram of a red mud comprehensive treatment device according to Embodiment 1 of the present invention.

FIG. 2 is a schematic diagram of another red mud comprehensive treatment device according to the second embodiment of the present invention.

FIG. 3 is a schematic diagram of an atmospheric micro-plasma generating device in Embodiment 1 of the present invention.

FIG. 4 is a left side view of FIG. 3 .

FIG. 5 is a schematic diagram of another atmospheric micro-plasma generating device according to the second embodiment of the present invention.

FIG. 6 is a plan (cross-sectional) view of FIG. 4 .

Fig. 7 is the original red mud XRD pattern of the red mud of Example 1.

FIG. 8 is the XRD pattern of the red mud of Example 1 after being treated by atmospheric micro-plasma discharge.

Fig. 9 is the original red mud XRD pattern of the red mud of Example 2.

FIG. 10 is the XRD pattern of the red mud of Example 2 after being treated by atmospheric micro-plasma discharge.

In the figure: 1. Control device, 2. Red mud pretreatment device, 3. Drying red mud silo, 4. Feeding device, 5. Atmospheric micro-plasma discharge device, 6. Red mud treatment chamber, 7. Discharging Device, 8. Grinding and screening device, 9. Treated red mud silo, 10, Gas recovery device, 11, Waste heat recovery device, 12, Red mud baffle, 13, Shell, 14, Red mud inlet, 15, Red mud Mud height control board, 16. Discharge power supply, 17. Multi-phase electrode, 18. Atmospheric micro-plasma uniform distribution plate, 19. Gas outlet, 20. Belt red mud reaction bed, 21, Red mud discharge baffle, 22 , Red mud outlet, 23, Red mud storage tank, 24, Ground electrode, 25, Stirrer.

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, Fig. 2, the method for comprehensive utilization of red mud provided by the present invention comprises the following steps:

1. The red mud is pretreated in the red mud pretreatment device 2, and the water is evaporated to remove the water, so that the red mud particles reach 70-200 mesh, and the water content is less than or equal to 5%;

2. Send the red mud into the red mud treatment chamber 6;

3. Start the atmospheric micro-plasma discharge device 5, and input the electromagnetic energy into the red mud treatment chamber through the multi-phase electrode. After coupling, the atmosphere in the red mud treatment chamber is ionized to generate electrons and charged particles. High-speed electrons and low-speed electrons in the micro-plasma Electrons and high-energy particles collide with the red mud particles continuously, making the red mud particles into a metastable or charged state, and at the same time generate a large number of electrons, electrons, metastable red mud particles and charged red mud particles, when the electron concentration When reaching 10 ¹⁴ ～ 10 ¹⁶ cm ^-3 , the collisions between these electrons and charged particles produce excitation, ionization, recombination and three-body recombination reactions, and the temperature of red mud increases rapidly to 600～1300℃; The rapid dissociation of complex oxides makes the complex oxides in red mud rapidly dissociate into relatively simple oxides, in which C, O and H are cracked into CO, CO ₂ , H ₂ and free H ₂ O; Na is also removed from the red mud. It is cracked and reacted with the atmosphere to become Na ₂ O, and part of O is lost in hematite to become magnetite;

3-1. As shown in Figure 1, a crawler-type red mud treatment bed is installed in the red mud treatment chamber. The red mud moves with the crawler during the reaction, and enters the discharge device with the crawler after the reaction is completed;

3-2. As shown in Figure 2, a stirrer is installed in the red mud treatment chamber to stir the red mud while the micro-plasma reaction occurs, so as to ensure the rapidity and uniformity of the reaction and facilitate the discharge of the red mud;

4. After the reaction, the complex oxides in the red mud are cracked into relatively simple oxides Fe ₃ O ₄ , Al ₂ O ₃ ·SiO ₂ , TiO ₂ , CaO · Al ₂ O ₃ , Na ₂ O and gases CO ₂ , CO, H ₂ and free H ₂ O;

5. The mixed gas of Na ₂ O, CO ₂ , CO, H ₂ and free H ₂ O is processed by the gas recovery device 10, Na ₂ O, CO ₂ and free H ₂ O gas can be dissolved in water and recovered, and CO and H ₂ are recovered become gas or provide fuel for red mud pretreatment;

6. After the treatment, the red mud is discharged, and the temperature of the red mud is 600-1300 ℃; the waste heat recovery device 11 set in the discharge device 7 recovers the residual heat of the red mud and sends it back to the red mud pretreatment device 2 as an auxiliary heat source;

7. When the temperature of the red mud drops to 100-200°C, the red mud enters the grinding and screening device 8, and the red mud is screened and ground into 0.074-4mm particles and sent to the treated red mud silo 9;

8. The treated red mud enters the beneficiation device from the treated red mud silo 9, and the iron and titanium in the red mud are respectively selected into high-grade iron ore by gravity separation, gradient magnetic separation, flotation, pickling, electric separation and other methods. powder and high-grade titanium ore powder, and the remaining part is used as raw material for refractory materials.

9. The entire process is controlled by the control device 1 using PLC or AI artificial intelligence to ensure that each process is continuous and orderly and to ensure proper coordination.

Under normal temperature and pressure, adjusting the voltage, frequency, power and phase difference of the discharge power supply will generate uniform micro-plasma in the red mud treatment chamber. The electron density of this micro-plasma reaches 10 ¹⁴ -10 ¹⁶ cm ^-3 . The moving electrons and high-energy particles collide with each other and are excited to generate more high-energy electrons, excited state particles and a wide variety of metastable active particles, such as:

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 ⁺

The high-speed electrons or high-energy particles generated in the atmospheric microplasma discharge collide with the red mud particles, and the electrons in the red mud particles are excited to become charged red mud particles or the red mud particles absorb part of the energy to become metastable particles or absorb electrons It becomes negatively charged red mud particles, and these electrons, ions, particles and red mud particles continue to collide and bombard each other, and further reactions such as ionization, excitation and three-body collision occur. O bond, Na-O bond, OH bond, CH bond and some complex bonds are dissociated under the action of high-energy electrons and high-energy particles, and become relatively simple oxides Fe ₃ O ₄ , Al ₂ O ₃ ·SiO ₂ , TiO ₂ , CaO·Al ₂ O ₃ , Na ₂ O and gases CO ₂ , CO, H ₂ and free H ₂ O. Due to the bombardment of a large number of electrons, ions and high-energy particles, the temperature of the red mud increased to 600-1300 °C; the gas generated during the reaction should be recovered and treated; The treated red mud is ground and screened and sent to the beneficiation device for beneficiation treatment.

Due to the use of atmospheric micro-plasma discharge reaction, complex oxides will rapidly dissociate into relatively simple oxides in a short period of time (5-600min) and undergo partial agglomeration, which provides great convenience for the production of high-grade concentrates and subsequent beneficiation ; Since the atmospheric micro-plasma reaction is an excitation reaction, only a small amount of energy can be provided to ensure the continuous reaction and less energy consumption; it can solve the red mud problem at one time at a low cost;

As shown in Figure 1, a red mud comprehensive utilization device includes: a control device 1, a red mud pretreatment device 2, a drying red mud silo 3, a feeding device 4, an atmospheric micro-plasma discharge device 5, and a red mud treatment chamber 6. Discharging device 7, grinding and screening device 8, gas recovery device 9, treated red mud silo 10, waste heat recovery device 11. The control device 1 respectively controls the red mud pretreatment device 2, the drying red mud silo 3, the feeding device 4, the atmospheric micro-plasma discharge device 5, the red mud treatment chamber 6, the discharging device 7, the grinding and screening device 8, the treatment Rear red mud silo 9 , gas recovery device 10 , waste heat recovery device 11 .

The red mud pretreatment device 2 is connected to the drying red mud silo 3, the drying red mud silo 3 is connected to the feeding device 4, the feeding device 4 is connected to the atmospheric micro-plasma discharge device 5, and the feeding device 4 is connected to the red mud treatment chamber 6, The atmospheric micro-plasma discharge device 5 is connected to the red mud treatment chamber 6, the red mud treatment chamber 6 is connected to the discharge device 7 and the gas recovery device 10, the discharge device is connected to the grinding and screening device 8, the discharge device 7 is connected to the waste heat recovery device 11, The waste heat recovery device 11 is connected to the red mud pretreatment device 2, the discharge device 4 is connected to the grinding and screening device 8, and the grinding and screening device 8 is connected to the treated red mud silo 9. After cooling, the red mud enters the treated red mud silo 9 and is then transferred. to the beneficiation device.

As shown in Figure 2, another red mud comprehensive utilization device includes: a control device 1, a red mud pretreatment device 2, a drying red mud silo 3, a feeding device 4, an atmospheric micro-plasma discharge device 5, and a red mud treatment device. Cavity 6, out Material device 7 , grinding and screening device 8 , treated red mud silo 9 , gas recovery device 10 , waste heat recovery device 11 .

The control device 1 respectively controls the red mud pretreatment device 2, the drying red mud silo 3, the feeding device 4, the atmospheric micro-plasma discharge device 5, the red mud treatment chamber 6, the discharging device 7, the grinding and screening device 8, the gas Recovery device 9 , treated red mud silo 10 , waste heat recovery device 11 .

The red mud pretreatment device 2 is connected to the drying red mud silo 3, the drying red mud silo 3 is connected to the feeding device 4, the feeding device 4 is connected to the red mud treatment chamber 6, and the atmospheric micro-plasma discharge device 5 is connected to the red mud treatment chamber 6. , The red mud treatment chamber 6 is connected to the discharge device 7 and the gas recovery device 10, the discharge device 7 is connected to the grinding and screening device 8 and the waste heat recovery device 11, and the waste heat recovery device 11 is connected to the red mud pretreatment device 2 and grinding and screening device 8 The red mud silo 9 after being connected and processed and the red mud after cooling enter the treated red mud silo 9, and then are transferred to the ore dressing device.

As shown in FIG. 3 and FIG. 4 , an atmospheric microplasma red mud treatment device according to Embodiment 1 includes a red mud baffle 12, a housing 13, a red mud inlet 14, a red mud height control panel 15, a discharge power source 16, Multiphase electrode 17 , atmospheric microplasma uniform distribution plate 18 , gas outlet 19 , belt red mud reaction bed 20 , red mud discharge baffle 21 , red mud outlet 22 , red mud storage tank 23 , ground electrode 24 .

As shown in FIGS. 5 and 6 , another atmospheric micro-plasma generating device according to the second embodiment includes: a casing 13 , a red mud inlet 14 , a discharge power source 16 , a multi-phase electrode 17 , and an atmospheric micro-plasma uniform distribution plate 18 , gas outlet 19, red mud outlet 22, ground electrode 24, stirrer 25.

The red mud pretreatment device 2 selects the BLH-RFM-04 type circulating dryer of Yancheng Bailihao Environmental Protection Machinery Manufacturing Co., Ltd. or the HZG type tumble dryer of Henan Taihang Machinery Equipment Co., Ltd. or the YH of Yinhai Machinery. Three-cylinder dryer;

The drying red mud silo 3 is used for storing the dried red mud powder;

The feeding device 4 adopts ultra-dense phase feeding or vacuum feeding, and the ultra-dense phase feeding device adopts PECHINEY ultra-dense phase conveying device. The conveying capacity is 10-300t/h; the flow rate of red mud is less than 0.28m/s; the pressure range: 2000-8000Pa. The vacuum feeder adopts ZKS series electric vacuum feeder from Xinxiang Renault Machinery Co., Ltd.; the vacuum degree is controlled at 5～90kPa, the conveying capacity per hour is 1～300 tons, and the power is 0.25～200kW;

As shown in FIG. 3 and FIG. 4 , an atmospheric micro-plasma discharge red mud treatment device according to Embodiment 1 includes: a red mud baffle 12, a casing 13, a red mud inlet 14, a red mud height control plate 15, Discharge power supply 16, multi-phase electrode 17, atmospheric micro-plasma uniform distribution plate 18, gas outlet 19, belt type red mud reactor The application bed 20 , the red mud discharge baffle 21 , the red mud outlet 22 , the red mud storage tank 23 , and the ground electrode 24 .

The casing 13 provides protection for the atmospheric micro-plasma discharge device 5 and is made of stainless steel, aluminum alloy or carbon steel; the red mud inlet 14 receives the red mud sent by the feeding device 4 and sends it to the red mud treatment On the belt-type red mud treatment bed 20 in the cavity 6; the red mud feeding baffle 12 ensures that the red mud moves along the movement direction of the crawler, and is made of refractory plate; the red mud height control plate 15 controls the height of the red mud on the crawler. It is made of refractory material plate; the red mud treatment chamber 6 ensures the formation of uniform atmospheric micro-plasma in the chamber, and there are multi-phase electrodes 17 inside and evenly distributed on the chamber, and the number of electrode phases is between 2 and 300. The size of the cavity is (600～30000)mm×(600～20000)mm×(600～400000)mm, the material of the cavity wall is stainless steel or carbon steel or alloy steel, and the inner wall of the cavity is provided with a micro-plasma uniform distribution plate 18. Ensure that uniform micro-plasma is generated under the action of multi-phase electrodes. The discharge power supply 16 provides high-frequency high-voltage current with a power of 150W-200,000W, a frequency of 10Hz-6GHz, and a voltage of 1.0KV-70KV; the red mud follows the crawler type red mud When the treatment bed 20 moves, a micro-plasma reaction occurs in the red mud treatment chamber 6; after the reaction, the red mud enters the red mud storage tank 23 through the red mud outlet 22, and a discharge baffle 21 is provided at the discharge end to ensure the discharge direction. The gas produced in the process of processing red mud enters the gas recovery device 10 for processing and recovery through the gas outlet 19; the red mud storage tank 23 is connected to the waste heat recovery device 11 to recover the residual heat of the red mud and sent back to the red mud and the processing device 2 as an auxiliary heat source; The width of the crawler-type red mud treatment bed is (500-2000) mm, and the length is (2000-380,000) mm; the crawler is made of stainless steel lined with high-aluminum refractory material; the crawler moving speed is 0.1-10m/min; the red mud treatment time is 5 ～600min; red mud temperature 600～1300℃ when discharging;

As shown in FIG. 5 and FIG. 6 , another atmospheric micro-plasma discharge red mud treatment device according to the second embodiment includes: a casing 13 , a red mud inlet 14 , a discharge power source 16 , a multi-phase electrode 17 , and an atmospheric micro-plasma Uniform distribution plate 18 , gas outlet 19 , red mud outlet 22 , ground electrode 24 , agitator 25 .

The casing 13 provides protection for the atmospheric micro-plasma discharge device 5 and is made of stainless steel, aluminum alloy or carbon steel; the red mud inlet 14 receives the dried red mud sent from the feeding device 4 and feeds it into. In the red mud treatment chamber 6, the red mud treatment chamber 6 ensures the formation of uniform atmospheric micro-plasma, and there are multi-phase electrodes 17 inside and evenly distributed around the red mud treatment chamber. The phase number of the multi-phase electrodes 17 is set between 2 and 300. Cavity size (200～10000)mm×(200～10000)mm×(200～10000)mm; the inner wall of red mud treatment chamber 6 is made of stainless steel or carbon steel or alloy steel, and the inside of the cavity is close to more The phase electrode 17 is provided with a micro-plasma uniform distribution plate 18 to ensure that the electrode generates uniform micro-plasma under the action of multiple phases; the discharge power supply 16 provides high-frequency high-voltage current, the power is 150W～100000W, the frequency is 10Hz～6GHz, and the electric current is 10Hz～6GHz. The pressure is 1.0KV～70KV; the red mud undergoes a uniform atmospheric micro-plasma reaction in the red mud treatment chamber 6. During the reaction process, the stirrer 25 continuously rotates and stirs to ensure the rapid and uniform micro-plasma reaction; after the reaction, the red mud passes through the red mud outlet 22 enters the discharging device 6; the gas generated in the process of red mud treatment enters the gas recovery device 10 through the gas outlet 19 for recovery processing; the rotation speed of the agitator is 1～1000r/min, and the processing time of red mud is 5～600min; Red mud temperature 600～1300℃;

The feeding device 6 selects a bucket conveyor or a screw conveyor to output red mud. The conveyor is equipped with a protective cover and a waste heat recovery device to collect high-temperature flue gas and send it back to the red mud pretreatment device 2 for red mud pretreatment. Auxiliary heat source; the bucket conveyor adopts the DS series bucket conveyor such as China Mining Heavy Equipment, the conveying speed is 0.15～0.30m/s, the conveying capacity is 30～500t/h, and the power is 1.5～300kW; For example, the GX series conveyors reloaded by China Mining Co., Ltd. have a rotating speed of 45~60r/min, a processing capacity of 9~130t/h, and a power of 1.1~55KW;

The gas recovery device 10 uses a venturi to recover the mixed gas of Na ₂ O, CO ₂ , CO, H ₂ and free H ₂ O produced in the process of red mud treatment, and is separated from gas and water, wherein Na ₂ O, CO ₂ A solution is formed; the remaining _CO and H are recovered as fuel gas;

The grinding and screening device 8 adopts Renault 520 linear vibrating screen or LN series circular vibrating screen, LNY600-2600 series rocking screen from Xinxiang Renault Machinery Co., Ltd.; or PLPZ series compound crusher produced by Shicheng High Rotation Bearing Co., Ltd. machine;

The treated red mud enters the treated red mud silo 9 and is then transferred to the beneficiation device, where iron is selected as high-grade iron ore powder through gravity separation and magnetic separation; The TiO ₂ in the red mud is selected to be high-grade titanium ore powder, and the remaining Al ₂ O ₃ ·SiO ₂ ·CaO is used as a refractory material or a cement material. Gravity selection first uses chute selection and then jigging or shaking table selection. The chute is used for the 5LL glass fiber reinforced plastic rotating spiral chute of Ganye Mining Machine; the jig is used for the JT series sawtooth wave jig machine of Ganye Mining Machine, with a stroke of 8.5~30mm, punching Times 80～180r/min, power 1.5～7.5KW; Shaker selection adopts LY and 6S series shakers produced by Ganye Mining Machine, lateral slope: 0～10°, stroke: 6～30mm, stroke time: 250～450r /min; magnetic separation adopts CTG-7522 dry magnetic separator of Ganye mining machine; flotation adopts XFD, XJK5Axiaoshi flotation machine of Jiangxi Ganye; electric separation adopts SJD produced by Shicheng County Yongrui Mining Machinery Factory -II type high voltage electric separator;

The control device adopts PLC or expert control system, and 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 The system utilizes an expert control system, such as Emerson Ovation expert control system.

Below in conjunction with specific embodiment, the present invention will be further described:

Example 1

The red mud pretreatment device 2, the red mud pretreatment device 2, the drying red mud silo 3, the feeding device 4, the atmospheric micro-plasma discharge device 5, the red mud treatment chamber 6, Gas recovery device 10, discharge device 7, waste heat recovery device 11, grinding and screening device 8, treated red mud silo 9; control device 1 to control the front and rear coordination of the entire comprehensive utilization red mud device and the smooth operation of production.

After the red mud pretreatment device 2 is activated by the control device 1, the drum of the red mud pretreatment device 2 is controlled to rotate, the gas is ignited, and then the domestic bauxite red mud from an aluminum plant is continuously fed into the red mud pretreatment device 2. The red mud is heated and evaporated in the rolling process from the inlet to the outlet in the drum of the pretreatment device 2, the output per hour is 20t/h, the water content of the red mud is less than 5% when the material is discharged, and the fineness is 70-200 mesh;

After the dried red mud is sent into the dried red mud silo 3, the feeding device 4 sends the red mud in the dried red mud silo 3 into the crawler-type red mud treatment chamber 6 through the red mud inlet 14. On the bed 20, the red mud baffle 12 and the red mud height control board 15 ensure that the red mud is evenly distributed along the movement direction of the crawler. The speed is 0.4m/min, and the crawler is made of stainless steel lined with high aluminum refractory material;

The atmospheric plasma discharge device 5 is started, and a micro-plasma discharge area is formed in the red mud processing chamber 6 through the atmospheric micro-plasma uniform distribution plate 18 between the multi-phase electrode 17 and the ground electrode 24 . In the atmospheric plasma discharge device 5, the maximum power of the discharge power supply 16 is controlled at 100KW, the frequency is controlled at 27.12KHz, and 100 multi-phase electrodes 17 are set;

The power of the atmospheric micro-plasma discharge device 5 increases proportionally with the increase in the amount of red mud. When the red mud treatment bed reaches full load, the power is increased to 100KW, and then the discharge power is adjusted according to the temperature of the red mud; The temperature is controlled every 3 meters along the length (8 in total), and the control device 1 controls the temperatures to be 30°C, 45°C, 80°C, 200°C, 400°C, 600°C, 900°C, and 900°C respectively; red mud discharge The temperature is 900℃;

The gas produced by the reaction in the red mud treatment chamber 6 enters the gas recovery device 10 for recovery;

The gas produced in the process of processing red mud enters the gas recovery device 10 through the gas outlet 19 for processing and recovery; after the treatment is completed, the red mud enters the red mud storage tank 23 through the red mud outlet 22 at the discharge end of the belt-type red mud treatment bed 20, and exits the red mud storage tank 23. The material baffle 21 ensures the discharge direction; the red mud storage tank 23 is connected to the waste heat recovery device 11 to recover the waste heat of red mud and return the waste heat to the red mud pretreatment device 2 as an auxiliary heat source;

After cooling, the red mud is sent to the grinding and screening device 7 through the discharging device 6 to be ground into fine powder, and then sent to the processed red mud silo 8, and then transferred to the ore dressing device for sorting.

Table 1 is a comparison of the chemical composition of red mud before and after the atmospheric micro-plasma discharge treatment, which shows that the content of silicon, aluminum, titanium, iron and calcium in red mud after the atmospheric micro-plasma discharge treatment changes little, and the potassium and sodium content before and after plasma treatment Respectively decreased by 61.60%, 65.62%.

Table 1 Comparison of chemical composition of red mud before and after microplasma treatment

The XRD analysis of the original red mud shown in FIG. 7 shows that the phase composition of the original red mud in Example 1 includes perovskite, calcite, hematite, ammonium oxalate, hydrated calcium iron garnet, α-type wollastonite, Dawsonite, aluminum magnesium serpentine, acid tartrate; of which:

Perovskite (PDF#72-1192) has 3 peaks, 32.87°, 33.269°, 86.149°;

Calcite (PDF#47-1743) has 6 peaks, which are 23.053°, 29.4°, 39.408°, 35.968°, 47.505°, 57.397°;

Hematite (PDF#33-0664) has 4 peaks, which are 33.111°, 24.148°, 62.405°, 84.885°;

Ammonium oxalate (PDF#72-0469) 13.957°, 27.223°, 29.091°, 32.281°, 44.87°, 55.649°;

Calcium iron garnet hydrate (PDF#87-1971) has 5 peaks, which are 17.57°, 32.4°, 39.965°, 55.675°, 63.946°;

α-type wollastonite (PDF#76-0534) has 10 peaks 19.121°, 32.782°, 34.245°, 34.834°, 35.352°, 36.847°, 37.39°, 54.29°, 62.331°, 71.832°;

Dawsonite (PDF#75-1464) has 14 peaks at 20.137°, 27.394°, 28.715°, 29.38°, 39.665°, 39.82°, 39.962°, 52.89°, 53.418°, 55.325°, 55.757° °, 57.312°, 59.262°, 62.232°;

Magnesium-aluminum serpentine (PDF#82-1867) has 3 peaks, which are 12.681°, 32.106°, 55.899°;

Acid tartrate (PDF#87-0649) has 6 peaks at 20.245°, 24.311°, 27.604°, 32.576°, 36.714°, 45.07°;

The XRD analysis shown in FIG. 8 shows that the phase composition of the red mud of Example 1 after treatment is perovskite (two crystal types), magnetite, magnetic hematite, titanium-rich magnetic hematite, calcium aluminum yellow feldspar;

in:

Perovskites come in two crystal forms:

(PDF#42-0423) has 7 peaks, which are 32.939°, 33.149°, 33.309°, 35.019°, 52.029°, 59.318°, 70.268°;

(PDF#78-1013) has 6 peaks. They are 35.014°, 37.03°, 44.43°, 47.53°, 52.237°, 59.078°;

Magnetite (PDF#89-0691) has 6 peaks, which are 35.529°, 43.158°, 47.243°, 57.041°, 62.627°, 62.68°;

γ-Fe ₂ O ₃ (PDF#39-1346) has 5 peaks, which are 35.65°, 43.304°, 44.723°, 50.027°, 65.092°;

Titanium-rich magnetic hematite (PDF#84-1346) has 5 peaks, which are 26.048°, 32.068°, 44.662°, 68.252°, 82.4°;

Mayenstone (PDF#74-1607) has 21 peaks, which are 21.082°, 24.088°, 25.995°, 29.232°, 31.513°, 37.424°, 37.61°, 39.459°, 41.238°, 47.34°, 48.886°, 50.397°, 53.323°, 56.421°, 57.113°, 61.135°, 65.005°, 71.807°, 84.513°, 84.746°, 86.598°;

The above analysis shows that the phase composition of the red mud in Example 1 before the atmospheric micro-plasma discharge treatment is complex. , The existence of calcite keeps the PH value of red mud at a high level, resulting in the unavailability of hematite and titanium ore with high content, and it is also harmful to the environment. After the atmospheric micro-plasma discharge treatment, the red mud phase of Example 1 changes into simple perovskite, magnetite, magnetic hematite (γ-Fe ₂ O ₃ ), titanium-rich magnetic hematite, and yellow feldspar . After the atmospheric micro-plasma discharge treatment, potassium, sodium, organic matter, C, O and H were almost volatilized due to the dissociation reaction, and the removal rates of potassium and sodium reached 61.6% wt and 65.62% wt, respectively, and the calcite disappeared. In addition to the mayenite, there are only perovskite, magnetite, magnetic hematite, and titanium-rich magnetic hematite in the phase composition. Before the atmospheric micro-plasma discharge treatment, perovskite has only three weak peaks, and hematite has only four peaks. After the atmospheric micro-plasma discharge treatment, the two crystal forms of perovskite become two. There are 7 strong peaks and 6 strong peaks, respectively. Iron becomes magnetite with 6 strong peaks, magnetic hematite γ-Fe ₂ O ₃ has 5 peaks, titanium-rich magnetic hematite has 5 peaks, and other components exist stably in the mayenite phase. Therefore, it is easy to separate iron and titanium into high-grade iron ore powder and high-grade perovskite powder through beneficiation; magnetite and magnetic hematite are selected by gravity and magnetic separation, and perovskite is selected by flotation, electric selected. That is to say, after atmospheric plasma discharge treatment, while solving the problem of reducing alkalinity of red mud, the complex phases in red mud become simple magnetite, perovskite and stable calcium-aluminum which are easier to be selected through beneficiation. Yellow feldspar can completely turn waste into treasure.

Embodiment 2

The red mud pretreatment device 2, the drying red mud silo 3, the feeding device 4, the atmospheric micro-plasma discharge device 5, the red mud treatment chamber 6, the gas recovery device 10, the discharging device are started in sequence through the control device 1 using AI control Device 7, waste heat recovery device 11, grinding and screening device 8, treated red mud silo 9; control device 1 to control the front and rear coordination of the entire comprehensive utilization red mud device and the smooth operation of production.

After starting the red mud pretreatment device 2 through the control device 1, control the rotation speed of the drum of the red mud pretreatment device 2, ignite the gas, and then continuously send the imported bauxite red mud from an aluminum plant into the red mud pretreatment device 2, The red mud is heated and evaporated in the rolling process from the inlet to the outlet of the pretreatment device 2 drum, the output per hour is 5t/h, the water content of the red mud is less than 5% when the material is discharged, and the fineness is 70-200 mesh;

After the dried red mud is sent into the dried red mud silo 3, the feeding device 4 sends the red mud in the dried red mud silo 3 into the red mud treatment chamber 6 through the red mud inlet 14, and waits until the red mud is added. When the volume reaches 10% vol of the red mud treatment chamber, start the stirrer 25 and start the atmospheric plasma discharge device 5 at the same time. A micro-plasma discharge region is formed in it. In the atmospheric plasma discharge device 5, the maximum power of the discharge power supply 16 is controlled at 60KW, the frequency is controlled at 2.45GHz, 60 multiphase electrodes 17 are arranged, and the rotational speed of the stirrer 25 is 3r/min;

The power of the atmospheric micro-plasma discharge device 5 increases proportionally with the increase of the amount of red mud. When the red mud in the red mud treatment chamber 6 reaches 70% vol (5t, the size of the red mud cavity is φ2500mm×1500mm), the power is increased to 60KW, Then adjust the power of the discharge power supply 16 according to the temperature control of the red mud; the processing time is 45min; the discharge temperature of the red mud is 1000℃;

The gas generated in the process of processing red mud enters the gas recovery device 10 through the gas outlet 19 for processing and recovery; after the treatment is completed, open the red mud outlet 22 at the discharge end of the red mud treatment chamber to send the red mud into the discharging device 7, and the discharging device 7 Connect the waste heat recovery device 11 to recover the red mud waste heat and send the waste heat back to the red mud pretreatment device 2 as auxiliary heat source;

After the treatment, the red mud is cooled to 100-200 ℃, and then sent to the grinding and screening device 8 through the discharge device 7 to be ground into fine powder and sent to the treated red mud silo 9, and then transferred to the ore dressing device for sorting.

Table 2 is a comparison of the chemical composition of red mud after micro-plasma treatment, which shows that the content of silicon, aluminum, titanium, iron and calcium in red mud after micro-plasma treatment is relatively small, and the content of potassium and sodium is reduced by 76.50% before and after plasma treatment, respectively. 71.22%.

Table 2 Comparison of main chemical components of red mud before and after micro-plasma treatment

The XRD analysis shown in FIG. 9 shows that the phase composition of the original red mud in Example 2 includes anatase, calcium sodium aluminate, sodium aluminosilicate formate, tobermorite, chlorite, sodium aluminosilicate formate, and titanic acid. Sodium, magnesium titanite, calcium sodium aluminate, hematite α-Fe ₂ O ₃ ; of which:

Anatase (PDF#27-1274, PDF#27-1274) has 6 peaks, respectively 25.361°, 53.97°, 55.166°, 62.199°, 62.768°, 82.739°;

Calcium sodium aluminate (PDF#26-0959) has 5 peaks, which are 34.556°, 41.166°, 47.285°, 69.443°, 69.798°;

Tombstone (PDF#36-0399 has 9 peaks, respectively 21.578°, 29.614°, 33.629°, 36.21°, 43.884°, 53.29°, 53.694°, 54.311°, 54.416°;

Beryl (PDF#14-0470) has 5 peaks, which are 25.235°, 32.977°, 36.92°, 41.643°, 64.326°;

Sodium silicoalumino formate (PDF#42-0218) has 2 peaks, 13.828° and 42.68° respectively;

Sodium titanate (PDF#37-0273) Na ₄ Ti ₅ O ₁₂ has 6 peaks, which are 13.968°, 16.11°, 33.502°, 35.429°, 36.964°, 40.412°;

Magnesite (PDF#06-0494) has 6 peaks, which are 21.318°, 53.694°, 62.162°, 71.643°, 78.452°, 84.528°;

Hematite α-Fe ₂ O ₃ (PDF#33-0664) has 7 peaks, which are 24.238°, 49.579°, 57.689°, 62.549°, 64.089°, 85.013°, 88.639°;

The XRD analysis shown in FIG. 10 shows that the phase composition of the red mud of Example 2 after treatment includes rutile, magnetite, clinoptilolite, calcium aluminum silicate and zeolite;

Rutile (PDF#34-0180, PDF#21-1276) has 5 peaks, respectively 27.426°, 27.437°, 56.54°, 65.378°, 79.799°;

Magnetite (PDF#03-0863, PDF#34-0180) has 7 peaks, which are 30.167°, 35.382°, 37.012°, 43.012°, 53.351°, 56.781°; 56.902°;

Clinoptiloxite (PDF#35-0610) has 15 peaks at 20.612°, 29.939°, 31.033°, 36.509°, 36.855°, 42.623°, 43.192°, 44.404°, 44.788°, 47.145°, 58.693° , 59.084°, 64.374°, 64.613°, 73.349°;

Calcium aluminosilicate (PDF#31-0249) has 4 peaks, which are 30.298°, 30.683°, 35.299°, 42.828°;

Zeolite (PDF#77-1551) has 12 peaks at 20.771°, 23.255°, 29.541°, 34.789°, 35.396°, 36.389°, 38.494°, 52.994°, 58.624°, 62.369°, 64.451°, 78.241° ;

The above analysis shows that due to the high content of iron and titanium in the red mud of Example 2, before the atmospheric micro-plasma discharge treatment, the titanium in the composition exists in the form of anatase and magnesium titanite, and the sodium in the form of calcium sodium aluminate, sodium silicoalumino formate , exists in the form of sodium titanate, iron exists in the form of hematite α-Fe ₂ O ₃ , and green cone, and other aluminum, silicon, calcium, and magnesium exist in the form of tombstone and zeolite. Calcium sodium aluminate, sodium silicoaluminum formate, and sodium titanate make it highly alkaline and highly corrosive; after the atmospheric micro-plasma discharge treatment, the XRD analysis of red mud in Example 2 found that the titanium from the anatase before treatment Ore, sodium titanate becomes rutile ore, iron is changed from hematite α-Fe ₂ O ₃ , chlorite to magnetite, aluminum and silicon become clinoptilolite, calcium aluminosilicate and zeolite. That is, after the atmospheric micro-plasma discharge treatment, sodium, ^OH- , oxalate are cracked into CO ₂ , Na ₂ O (gaseous), CO, H ₂ and free H ₂ O volatilized at high temperature, Fe- Part of O in the O bond is separated from iron under the action of high-energy electrons and high-energy particles, so that hematite becomes magnetite; titanium changes from anatase to more stable rutile; silicon, aluminum, and calcium undergo atmospheric microplasma After bulk discharge treatment, calcium aluminum silicate, zeolite and clinoptilolite are recombined to form. Magnetite can be easily selected by gravity separation and magnetic separation, rutile ore can be easily selected by flotation and electric separation, and the remaining calcium aluminum silicate, zeolite and clinoptilolite can be used to manufacture cement and refractory materials. That is to say, after the atmospheric plasma discharge treatment, regardless of the composition of the red mud, the alkali reduction problem of the red mud can be solved, and the complex phases in the red mud can be changed into simple magnetite, Rutile ore and stable cement and refractory raw materials. So as to realize the comprehensive utilization of red mud at a one-time low cost.

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 limitations of the present invention. Embodiments are subject to variations, modifications, substitutions and variations.

Claims

A method for comprehensive utilization of red mud is characterized by comprising the following contents:

(1) The red mud is pretreated, and the water is evaporated and then ground; the red mud particles are required to be 70-200 mesh, and the water content is less than or equal to 5%;

(2) Sending the red mud into the red mud treatment chamber; the red mud treatment chamber is provided with a stirrer or a belt-type red mud treatment bed, and the stirrer stirs the red mud while the micro-plasma reaction occurs to ensure the plasma reaction Fast, uniform and convenient red mud discharge; the belt-type red mud treatment bed makes the red mud move with the crawler while the micro-plasma reaction occurs. After the reaction, the red mud enters the discharge device with the crawler;

(3) Start the atmospheric micro-plasma discharge device, and input the electromagnetic energy into the red mud treatment chamber through the multi-phase electrode using the discharge power source, so that the atmosphere in the red mud treatment chamber is ionized to generate electrons and high-energy charged particles, and the electrons and high-energy charged particles are combined with The red mud particles are continuously collided and bombarded, excited to generate a large number of electrons, high-energy particles, free radicals, metastable red mud particles and charged red mud particles and undergo ionization, recombination and three-body recombination reactions, so that the temperature of red mud is rapidly increased to 600～1300℃, complex oxides in red mud particles crack rapidly;

(4) After the reaction, hematite and other complex oxides in red mud become magnetite, TiO 2 series, Al 2 O 3 ·SiO 2 series, CaO TiO 2 series and gases Na 2 O, CO 2 , CO, H 2 , free H 2 O;

(5) The mixed gas of Na 2 O, CO 2 , CO, H 2 and free H 2 O was collected by venturi for dust removal, Na 2 O, CO 2 and free H 2 O gas were dissolved in water, and the mixed gas of CO and H 2 was recovered Become gas or used for red mud pretreatment as fuel;

(6) After the treatment is completed, the red mud is discharged, and the red mud temperature is 600-1300 ° C when discharging, and the residual heat of the red mud is recovered by the waste heat recovery device and then transported to the red mud pretreatment device for drying the red mud;

(7) When the red mud temperature drops to 100～200℃, the red mud enters the grinding and screening device, and the red mud is screened and ground into 0.074～4mm particles and sent to the treated red mud silo;

(8) The treated red mud enters the ore dressing device from the treated red mud silo, and successively selects iron and titanium from the red mud into high-grade iron ore powder through gravity separation, gradient magnetic separation, flotation, pickling, and electric separation. and high-grade titanium ore powder, and the remaining part is used as refractory raw material.
A red mud comprehensive utilization device for comprehensive utilization of red mud according to claim 1, characterized by comprising: a red mud pretreatment device, a drying red mud silo, a feeding device, an atmospheric micro-plasma discharge device, a red mud Treatment chamber, gas recovery device, discharge device, waste heat recovery device, grinding and screening device, treated red mud silo, control device; control device controls red mud pretreatment device, drying red mud silo, feeding device, atmospheric micro Plasma discharge device, red mud treatment chamber, gas recovery device, discharge device, waste heat recovery device, grinding and screening device, red mud silo after treatment; red mud pretreatment device is connected to drying red mud silo and drying red mud silo Connect the feeding device, the feeding device is connected to the red mud treatment chamber, the atmospheric micro-plasma discharge device is connected to the red mud treatment chamber, the red mud treatment chamber is connected to the discharge device and the gas recovery device, the discharge device is connected to the grinding and screening device, and the discharge device is connected. The device is connected to the waste heat recovery device, the waste heat recovery device is connected to the red mud pretreatment device, the discharge device is connected to the grinding and screening device, and the grinding and screening device is connected to the treated red mud silo; the red mud pretreatment device evaporates the water in the red mud, which can The hot air heating method is used for treatment, and the residual heat of the treated red mud is used as an auxiliary. During the heating process, the red mud raw materials are transported by crawler type, tunnel type or roller and sent to the drying red mud silo. The pretreatment temperature of red mud is 150-280 °C. The processing time is 60min-600min; after drying, the red mud moisture is less than 5%, and the red mud particles are 70-200 mesh; after discharging, the red mud is put into the red mud silo; the feeding device uses a super-dense phase conveying device for feeding Or vacuum feeding, the red mud is transported to the atmospheric micro-plasma red mud treatment device; the super-dense phase feeding is to convert the red mud bed through the fluidization operation into a "gas-solid two-phase" fluid, so that , the potential energy of the red mud in the drying red mud silo is transmitted to the flow direction through this "gas-solid two-phase" fluid, and a pressure gradient is formed, forming red mud columns of different heights in each equilibrium column, and the The red mud material column pushes the red mud to the lower direction of the material 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; Pressure suction, the vacuum degree is controlled at 5-90kPa, the conveying volume per hour is 1-300 tons, and the power is 0.25-90kW; the atmospheric micro-plasma discharge device includes a discharge power supply, a multi-phase electrode and a ground electrode; the discharge power supply power is 50W～ 300000W, frequency 10Hz～6GHz, voltage 1.0KV～70KV; the multi-phase electrode undertakes high voltage and keeps a certain distance from the ground electrode, during which atmospheric ionization occurs; the distance between the multi-phase electrode and the ground electrode is between 1.0mm and 300mm; The mud treatment chamber accepts the red mud sent by the feeding device and ensures that the treated red mud is transported out; the red mud treatment chamber can be equipped with a mixer or a crawler-type red mud treatment bed or agitator to ensure that the red mud particles and atmospheric micro-plasma The body is fully contacted and collided, and the reaction is fast and uniform; at the same time, after the red mud treatment is completed, the red mud is pushed to the discharge port; When the micro-plasma reaction treatment is performed, it moves with the belt, and enters the discharging device after the reaction; the rotation speed of the agitator is 1~1000r/min, the moving speed of the crawler is 0.1~20m/min, and the processing time of red mud is 5~600min. The mud temperature is 600-1300°C; the gas recovery device uses the venturi treatment method to treat the gas generated in the process of red mud treatment, and after separation of gas and water, Na 2 O, CO 2 and free H 2 O form a solution; the remaining CO and H 2 are recovered into gas; the discharging device is discharged by a bucket discharger or a screw conveyor, and the bucket discharger or screw conveyor is provided with a protective cover and a waste heat recovery device to collect high-temperature flue gas and dispose of the high-temperature flue gas. After the flue gas is dedusted, it is sent to the red mud pretreatment device to dry the red mud; the waste heat recovery device uses a high-temperature fan to transport the high-temperature flue gas to the red mud preheating device. The high-temperature fan can be an axial-flow hot-air circulating fan or a centrifugal hot-air circulating fan, and electrostatic precipitator can be used for dust removal; The red mud is ground and screened, and the vibration frequency is 6-700 times/min and the amplitude is 2-50 mm during vibration grinding and screening. After grinding and screening, the red mud is put into the treated red mud silo.