CN110947525B

CN110947525B - Nanobubble flotation column

Info

Publication number: CN110947525B
Application number: CN201911290924.9A
Authority: CN
Inventors: 李宾; 李楠; 王江; 屠坤; 熊壮
Original assignee: Individual
Current assignee: Individual
Priority date: 2019-12-16
Filing date: 2019-12-16
Publication date: 2020-10-16
Anticipated expiration: 2039-12-16
Also published as: WO2021120370A1; CN110947525A

Abstract

The invention provides a nano bubble flotation column which comprises a slurry pump, a cyclone jet nano cavitation bubble nozzle, a slurry distributor, a plurality of cyclone jet nozzles, a flotation column and a plurality of conveying pipelines. The invention generates nano bubbles or local disturbance in flowing ore pulp by a slurry pump, a cyclone jet nano cavitation bubble nozzle and a cyclone jet nozzle so as to activate flotation; the application of the method in mineral flotation can not only improve the recovery rate of minerals, but also reduce the dosage of reagents and energy consumption, improve quality and enhance efficiency, and achieve the aims of large-scale and intelligent industrial production of flotation equipment.

Description

Nanobubble flotation column

Technical Field

The invention belongs to the field of mineral flotation or industries such as petroleum, sewage, papermaking and the like, and relates to an ore pulp flotation device, in particular to a nanobubble flotation column.

Background

With the continuous development and consumption of mineral resources on earth by human beings, ore resources rich in ores and easy to process are gradually reduced, and the demand of metal materials is increased, so that poor, fine and miscellaneous ores have to be mined and sorted. Such ores must be ground very finely to allow sufficient monomer dissociation of the useful minerals, which in some cases means that the material needs to be ground to a particle size of less than 20 microns. However, as the ore particle size decreases, the flotation behavior of the mineral particles changes fundamentally, and conventional flotation processes can only process those minerals that are floatable and easy to float and have no special requirements for flotation reagents, flotation technology, flotation equipment and the like, but have difficulty in meeting the requirements for sufficient recovery of these useful fine-fraction minerals.

Therefore, the separation of coarse and fine minerals is always a great problem in the mineral separation industry, and the fine minerals are mainly characterized by small mass, large specific surface area and high surface energy. The small mass makes the probability of collision between hydrophobic ore particles and bubbles small, and the energy barrier between the ore particles and the bubbles is difficult to overcome and the ore particles and the bubbles are adhered to the surfaces of the bubbles, so that the effective mineralization of the ore particles and the bubbles is realized. The large specific surface area and the high surface energy cause non-selective agglomeration to easily occur between gangue mineral grains and useful mineral grains, thereby causing the phenomenon of 'foam inclusion' and reducing the grade of concentrate. In order to solve the problem that fine-grained minerals are difficult to float due to the quality effect and the surface effect, researchers at home and abroad carry out a great deal of research on the technology and equipment of a flotation column, and under the background, a plurality of new technologies and new equipment of the flotation column appear, so that the flotation column has good prospects for column type separation of coarse-grained and fine-grained minerals.

The development history of flotation columns, the idea of flotation column design, began in 1915. The canadian engineer BouTTin developed a flotation column with a foam rinse water unit of modern significance in 1961, and then rapidly turned over the hot tide of flotation column research and development applications in the former soviet union and china. After the 80 s in the 20 th century, under the guidance of some new design ideas, the flotation columns have great progress in bubble generators, inflation performance and operation stability, and a plurality of efficient flotation columns such as Flotaire flotation columns, MTU type packed medium flotation columns, cyclone inflation type flotation columns and the like are gushed out. The most representative of the various types of flotation columns is the jameson flotation column invented and designed by professor jameson in 1987, and the flotation column has brand new breakthroughs in structure, mineral supply mode and sorting mechanism and solves a series of problems caused by column height. The product becomes mature day by day. The flotation column is used as a center to carry out fine-grained mineral flotation research, and research on a bubble gas production mode, a flotation column structure, a flotation system provided with various detection and control devices and the like becomes a research development direction of flotation equipment in the future.

The current state of research and progress of flotation columns, several types of flotation columns:

1 Jameson (Jameson) flotation column, the pulp passes through a nozzle to form a jet which enters a conduit, the vacuum created by the jet draws air in and shears into bubbles in the pulp chest, the downcomer acts as a "reactor", and the concentrate froth product is discharged from the flotation cell. The column has the advantages that: the method has the advantages that a split flotation strategy of mineralization and separation is realized; the column body is short, and the height of the industrial flotation column is only 2.0 meters; the retention time of the ore particles is short, the gas content of the ore pulp is high, and the flotation efficiency is high; and fourthly, the ore pulp forms negative pressure inspiration through jet flow, and the power equipment is a feeding pump. The column has the following disadvantages: the method has the advantages that the retention time of ore pulp is short, and multi-section scavenging is often required to be arranged; the ore feeding fluctuation is large, and the separation is unstable; and thirdly, forming 'aeroelasticity' in the cylinder body to influence the sorting effect.

A packed medium floatation column developed by the university of Michigan industry, USA, is characterized in that a conventional floatation column is filled with a packed medium, the layers of the packed layer are arranged at an angle of 90 degrees, and fine and tortuous pore passages enable ore particles to be in close contact with bubbles, so that the separation effect is enhanced. The pan feeding is given into from the main part middle part, and compressed air lets in at the bottom, and the concentrate overflows from the top and discharges, and the tailing is discharged from the bottom, and the top sets up water jet equipment. The flotation column not only has the advantages of the traditional flotation column, but also overcomes the problems that the bubbles of the traditional flotation column are easy to combine, strong turbulence is easy to generate, flow states such as flower turning and the like are easy to form, and a bubble generator which is easy to scale and block is eliminated. The column is filled with multiple layers of wave-shaped media to form a plurality of regular tortuous channels, and compressed air entering from the lower part forms uniform bubbles and carries hydrophobic mineral particles to float upwards when passing through the channels. The filling type flotation column effectively implements the basic column flotation process of foaming, mineralizing and separating, but the defects of easy blockage of filling materials and high manufacturing cost not only affect the implementation effect of filling, but also affect the industrial application of the filling flotation column.

A jet flow type flotation column is novel flotation equipment which is researched and developed by Drift of Zingiber officinale according to the free jet flow flotation principle. The Lushijie provides a novel downward concurrent flow jet type flotation column-KYZ type flotation column according to a jet flow theory. A flotation column with a jet aerator is researched by NFMeseheriaikov and the like of the national university of Monskore, the type of flotation column has a good flotation effect on large-grained minerals, is popularized and applied to the flotation of 3 mm-0.8 mm-grade potassium salt and 2 mm-0.5 mm-grade diamond, and obtains a good technical index of which the unit production efficiency is several times higher than that of any other type of flotation machine. A novel K phi M series flotation column developed by Wular mineral processing research and design institute is composed of a jet aerator, a micro-bubble generator, a central flotation pipe, a discharging device and a foam collecting tank. The flotation column eliminates the phenomenon of convective movement of ore particles and bubbles in the conventional flotation column, and can realize roughing, fine selection and scavenging operations in one flotation device.

The cyclone-static microbubble flotation column comprises a column separation section, a cyclone separation section and a pipe flotation device. The whole equipment is a column body, a column separation section is positioned at the upper part of the whole column body, a spray header and a foam concentrate collecting tank are arranged at the top of the column body, and finally concentrate is discharged; the ore feeding point is positioned at the middle and upper parts of the column separation section, the cyclone separation section adopts a separation cyclone structure and is in straight-through connection with the upper and lower structures of the column separation section, and finally tailings are discharged from a underflow port of the cyclone separation section. The pipe flotation device is arranged outside the column body of the equipment, and an outflow pipe of the pipe flotation device is connected with the column body of the cyclone separation section along the tangential direction, which is equivalent to a tangential feeding pipe of the separation cyclone. The tube flotation device comprises a bubble generator and a flotation tube section. The bubble generator introduces gas by means of jet flow and crushes the gas into bubbles, the pressurized circulating ore pulp enters the bubble generator to form a three-phase system containing a large amount of bubbles and realize turbulent mineralization, and then enters the cyclone separation section at a high speed in a tangential direction. Thus, the tube flotation device forms a rotational flow force field at the bottom of the flotation column in a tangential mode while finishing flotation aeration and turbulent mineralization, and a continuous separation process is realized.

Other novel flotation columns

1. The flotation column is mechanically agitated. Conventional columns have a relatively low capacity for flotation of coarse minerals and mechanical agitation mechanisms, such as a WemCo/Leeds flotation column, have been added to the column to improve coarse flotation. The flotation column is provided with a mechanical air-charging stirring device, and coarse grains are uniformly stirred and are not easy to precipitate; several layers of grid medium rollers are arranged in the column, and the concentrate grade can be controlled by automatically adjusting the gap between the rollers; and (4) adding washing water at the top of the column to remove gangue inclusions in the foam.

2. A flow stabilizer flotation column. Aiming at the problem of combining axial mixing and foam, Michigen technology university develops a flotation column with a horizontal flow stabilizer, and the horizontal flow stabilizer consists of a plurality of simple plates with holes. In addition, Meloy et al, the university of West Virginia, USA, proposed a two-dimensional flotation column, the interior of which is divided into a number of cells by packing, so that a series of products of continuously varying grades can be produced, similar to a shaker.

And 3, an LM flotation tank. The equipment comprises a flotation tank, a column, a buffer tank before a pump and a pump. The ore pulp enters a buffer tank in front of the pump, then the pump is used for vertically pumping a human body column downwards, compressed air is introduced, the mixing of the ore pulp and bubbles is completed in the column, and feeding is provided for the flotation tank. The high-intensity mixing can enable ore pulp to finish particle collection in a very short time and has high recovery rate. The froth is discharged from the bottom of the column into the flotation cell and a thicker froth layer is formed in the upper part of the flotation cell. The LM flotation cell is a novel flotation device. It can be used for treating non-magnetic, magnetic and non-metallic minerals.

4. And (4) a micro-bubble flotation column. The equipment adopts a mineralization separation mode of a traditional flotation column, and highlights the 'micro-bubble effect' of flotation. The revolutionary contribution of the flotation column is in the revolution of the foaming mode-fluid mixing into bubbles (the specific embodiment is adding static stirring blades). The idea of mixing fluid into bubbles and improving the column separation efficiency by the micro bubble effect is commonly adopted in the design of flotation columns.

The research on the bubble generator is advanced, and the bubble generator of the flotation column can be divided into an inner foamer and an outer foamer according to different foaming modes and foaming devices. The foaming system, which has been commonly used in recent years, includes the following:

1. shearing, contacting and foaming. The slurry flowing at high speed is contacted with gas in a suitable manner, such as by the creation of bubbles through a wire mesh or a packing medium. The shearing contact foaming is to crush gas into bubbles by using a gas-liquid mixing process, wherein the size of the bubbles is mainly determined by liquid turbulence and continuous mixing time, and finally reaches the critical size of the bubbles matched with the energy state of a system.

2. And (4) microcellular foaming. The gas is foamed through a microporous plastic, rubber, canvas, nylon, microporous ceramic tube or pebble layer. The microcellular material cannot fully play a role because microcellular foaming is easy to block, and the increase of the inflation amount (pressure) directly causes the increase of the size of bubbles, so that the method is less adopted at present.

3. Reducing the pressure or raising the temperature for foaming. The solubility of air in water is about 2%, and when the pressure is lowered or the temperature is raised, the dissolved gas is evolved to produce bubbles.

4. And (4) jetting and foaming. The pressurized gas stream is injected into the pulp or the pulp injection gas stream can both generate bubbles suitable for flotation. The method is that the liquid is changed into a dispersed phase, and then the liquid is gradually changed into a continuous phase gas along with the increase of pressure, so that the liquid is gradually dispersed into micro bubbles from the initial continuous phase. Jet foaming is a great revolution of bubble generation.

5. The electrolysis of water generates bubbles. The electrolysis water principle is utilized, under the electrified condition, the electrolysis mode is adopted to decompose water to generate hydrogen and oxygen, the hydrogen and oxygen generated by electrolysis have small diameters, the bubble amount can be controlled by current regulation, and the micro-bubble flotation by utilizing the electrolysis water technology is an innovation of the bubble generation technology.

Internal foamer

1. A filter disc type foaming device. Covering a layer of filter cloth on a filter disc of the disc filter, and flatly placing the filter cloth at the bottom of a flotation column to obtain the foam maker. The bubble generated by the foam maker is uniform, but is easy to wear.

2. A vertical pipe foamer. Uniformly distributing a plurality of vertical pipes with the diameter of 40 mm-75 mm and the height of 300 mm-500 mm at the bottom of the flotation column, and connecting the vertical pipes with a pressure controller pipe network. The upper and lower section interfaces of each vertical pipe are provided with porous medium materials. Such internal foamers are prone to clogging due to the tendency of the slime to settle on the surface of the porous media.

3. A gravel bed layer foaming device. Placing the gravel with the diameter of 8 mm-20 mm between the upper and lower layers of screens to form a gravel bed layer with the thickness of 300 mm-600 mm. This bubbler is less prone to clogging, but the bubbles produced are large in diameter.

External foamer

1. A water/air jet aerator. Such an inflator is classified into 3 types: TurboAir type, Flotair type and CESL type. The TurboAir model was developed by the U.S. Ministry of mining. Glass balls or quartz particles are filled in an inflator with an inner diameter of 50mm to generate fine bubbles with a diameter of 0.1mm to 0.3mm under high pressure. The FloTair type bubbler manufactured by the company deistterconcentrator, usa disperses pressurized air from an external diffuser into a tank through an internal aeration plate, and operates under the conditions of a pressure of 300Ka to 480Ka and a flow ratio of air to water of about 30 to generate fine bubbles having a diameter of about 0.1 mm. The CESL type aerator is produced by the company CominCoEngineering serving CeLTd (CESL) of Canada in 1988, a gas disperser outside a flotation column generates an air-water mixture which is dispersed into a flotation column through a metal pipe, the pressure is operated under 300 Ka-600 Ka, the diameter of bubbles is 0.3 mm-0.4 mm, the gas content can be ensured to reach 50%, and a porous metal pipe can be replaced in the operation and the operation rate is higher. CESL type inflators are in turn widely used in north america, south africa, and the like.

2. An air jet inflator. Minovextechrologices, Canada developed a mechanism for generating bubbles by blowing only air (air jets) without water. The aerator has simple structure composed of needle valve and bubble spraying hole, large hole diameter, no blockage due to ceramic coating on the surface, long service life of 2a, and easy application due to generated bubbles with diameter of 0.5-3.0 mm.

Minnovex static mixer. The mixer utilizes ore pulp and gas flowing at high speed to form bubbles under the action of the shearing piece, has the characteristics of easy replacement and online bubble size regulation, but has higher processing precision requirement.

4. A porous venturi. When water flows through the porous pipe at high speed, the pressure in the pipe is lower than the atmospheric pressure, air enters spontaneously to be mixed with the water, and bubbles are generated under the high-speed shearing action of the porous medium. When the pressure is released, a large amount of micro-bubbles are separated out and then enter the rotational flow section along the tangent line.

5. A swirler type aerator. In the cyclone flotation machine, the ore pulp and the air bubbles are fully mixed by centrifugal force, and the air can be fed automatically or pressed in. Centrifugal force moves ore particles to the wall of the tank, and bubbles rise inward, so that the collecting speed is high, and therefore, the flotation effect on fine-grained minerals is good, but the separation of coarse-grained and high-density minerals is not good.

The research of the bubble mineralization mode is advanced, the early flotation column mineralization mode mostly adopts a counter-current mineralization mode, and the mineralization modes of counter-current mineralization, concurrent mineralization, pipe flow or centrifugal mineralization and various mineralization combinations appear later along with the continuous progress of the technical research of the flotation column.

And (3) a countercurrent mineralization flotation column, and a countercurrent collision mineralization type flotation column such as a CPT flotation column, an FXZ full static flotation column and the like. CPT flotation column. The column was developed by canadian process technology corporation and its core is its air dispersion system, of which there are four types, the latest being SlamJeT dispersers and SParJeT dispersers. The ore pulp treated by the flotation agent is fed from a position about 1 m-2.0 m below the top of the column, and a gas disperser which can be disassembled and repaired from the outside of the column is arranged near the bottom of the column. The micro bubbles generated by the gas disperser freely rise under the action of buoyancy, the mineral particles in the ore pulp freely fall under the action of gravity, the rising bubbles and the falling mineral particles are contacted and collided in the collecting area, and the hydrophobic mineral particles are captured and attached to the bubbles, so that the bubbles are mineralized. The mineralized bubbles loaded with useful mineral particles continuously rise to enter a fine separation area, and are gathered at the top of the column to form a mineralized foam layer with the thickness of 1m, and the foam layer is cleaned by flushing water flow, so that gangue particles carried by the foam layer and entering the foam layer fall off from the foam layer, and thus, higher-grade concentrate is obtained. The tailing pulp is discharged from the bottom of the column, and the whole flotation column works under the condition of positive bias flow. FXZ all static flotation columns. FXZ static flotation column is developed by Beijing school district of China university of mining industry, and comprises static flotation column and drop box matched with the static flotation column. The flotation column has no rotational flow, ore pulp floats from top to bottom and flowing bubbles float from bottom to top, target ore particles are adhered to the bubbles after colliding with the bubbles, concentrate foam floats to the top and overflows to be discharged, and tailings are discharged to the bottom along with water flow. The falling box is not provided with moving parts, the flotation reagent is sprayed into the falling box in an emulsion shape through high-pressure air and is mixed with flotation feed, ore pulp flows from top to bottom due to the action of gravity, the reagent and ore particles are fully contacted in the flowing process, the floatability of target minerals is improved, and after the flotation reagent enters the flotation column, the flotation speed and the treatment capacity of the flotation column can be improved.

The forward flow mineralization flotation column introduces air by using a jet flow principle, a conical contraction pipe of the flotation column is connected with a horn pipe in a hollow chamber, when high-speed water flows from the conical contraction pipe to the horn pipe, a larger flow speed is formed at an outlet of the conical contraction pipe due to the gradual reduction of the section of the water flow, so that the pressure at the outlet is reduced to be lower than the atmospheric pressure, and negative pressure is formed in an air suction chamber, so that the air enters the hollow chamber from the outside. A reflecting false bottom is arranged at the bottom of the sorting tank and has the function of crushing air carried by high-speed water flow into bubbles and dispersing the bubbles to the whole sorting tank. The equipment has the advantages of small bubble diameter, high air retention, uniform air dispersion, simple structure, convenient operation, no moving part and good sorting index.

Pipe flow mineralizing flotation columns, which are exemplified by jet flow flotation columns, Jameson flotation columns, and the like, with Jameson flotation columns being most typical. The Jameson flotation column is developed in Australia, and the working principle of the Jameson flotation column is that ore pulp with a well-mixed medicament is pumped into a mixing head of a lower guide pipe through a feeding pipe by a pump, a jet flow is formed through a nozzle to generate a negative pressure area, air is sucked in to generate bubbles, ore particles are collided and mineralized with the bubbles in the lower guide pipe, downward flow is discharged into the separation column from a bottom opening of the guide pipe, the mineralized bubbles rise to a foam layer on the upper part of a column body, the foam layer is refined through washing water and then flows into a concentrate chute, and tailings are discharged. The aeration stirring device is a key component of the Jame-son flotation column, adopts the jet pump principle, converts the pressure energy of ore pulp into kinetic energy by a nozzle, forms negative pressure in a sealing sleeve, and sucks air by an air guide pipe. The jet-flow wrapped gas enters the mixing sleeve after passing through the sealing sleeve, and under the action of the highly turbulent fluid, the gas is divided into bubbles and continuously collides and adheres to the ore particles to obtain mineralization. The disperser is equivalent to a static impeller and uniformly disperses the vertically downward ore pulp along the radial direction.

The rotational flow mineralization flotation column is provided with a rotational flow inflatable flotation column. The flotation column was developed by the university of utah, usa. The ore pulp is fed in along the tangential direction under certain pressure, air enters from the porous column wall, the foam product moves upwards through the inner screw to be discharged, and settled sand is discharged from the bottom. The equipment is efficient, but the wall wear is severe. It provides a high-efficiency air-charging mineralization mode, which corresponds to the countercurrent mineralization and highlights the vertical characteristic of the foaming and mineralization processes. In the background of a centrifugal force field with higher intensity, the vertical mineralization mode not only improves the mineralization efficiency of flotation, but also reduces the lower limit of the flotation granularity. And the gravity separation effect in the centrifugal force field forms the comprehensive force field advantage of fine material separation.

The volume of a cell body of the direct current-countercurrent multistage mineralized flotation column is 1580m³And 4.6m higher. ByEach column body has different hydrodynamics and aeration states, and the flow speed and the residence time of ore pulp can be adjusted by changing the section of the column body, so that different floatability particles can be recovered. With the research of the flotation column, the bubble mineralization mode of the flotation column also presents the diversification characteristic according to the characteristics of the developed flotation column, and the mineralization mode of various combinations becomes an important direction for the research of the flotation column.

In recent years, the grade of nickel of raw ore treated by mineral separation is reduced year by year, the content of magnesium oxide is increased day by day, the embedded particle size of the ore is finer, and the search for efficient flotation equipment is one of the important directions for future mineral separation development.

Disclosure of Invention

In order to solve the above problems, the present invention provides a nanobubble flotation column, which comprises a slurry pump, a cyclone-jet nanobubble nozzle, a slurry distributor, a plurality of cyclone-jet nozzles, a flotation column assembly, and a plurality of transport pipes;

the rotational flow jet nano cavitation bubble nozzle is composed of a first outer sleeve, a first ore pulp input pipe, a first throat pipe and a first negative pressure air suction pipe, wherein the first ore pulp input pipe and the first throat pipe are respectively inserted from two ends of the first outer sleeve, a first mixing chamber is formed between an outlet of the pipe wall of the first ore pulp input pipe, which is inwardly converged, and an inlet of the first throat pipe, the first negative pressure air suction pipe is arranged at the junction of the first ore pulp input pipe and the first mixing chamber, and is vertical to the first outer sleeve, and a plurality of first spiral flow deflectors are arranged on the inner wall of the first ore pulp input pipe;

the upper part of the pulp distributor is a cylindrical barrel, the lower part of the pulp distributor is tapered and contracted to form a first tapered barrel part, the bottom end of the first tapered barrel part is provided with a pulp inlet, the side wall of the barrel is provided with one to many circles of pulp outlets along the circumferential direction, and each circle is provided with a plurality of pulp outlets;

the cyclone jet nozzle consists of a second outer sleeve, a second ore pulp input pipe, a second throat pipe and a second negative pressure air suction pipe, wherein the second ore pulp input pipe and the second throat pipe are respectively inserted from two ends of the second outer sleeve, a second mixing chamber is formed between an outlet of the inward convergence of the pipe wall of the second ore pulp input pipe and an inlet of the second throat pipe, two L-shaped second negative pressure air suction pipes are arranged at the junction of the second ore pulp input pipe wall and the second mixing chamber, the long edges of the two second negative pressure air suction pipes are parallel in the same direction and are converged into a converging pipe at the upper part, and an air suction pipe valve is arranged on the converging pipe and used for controlling the air suction amount; the inner wall of the second ore pulp input pipe is provided with a plurality of second spiral flow deflectors;

the flotation column group consists of a plurality of pulp flotation columns, each pulp flotation column comprises a hollow cylinder, the upper part of the hollow cylinder is a polygonal cylinder body, the lower part of the hollow cylinder body is in a polygonal pyramid shape and shrinks to form a second cone cylinder part, and the bottom end of the second cone cylinder part is provided with a coarse particle tailing discharge pipe; a high steady flow distributor is arranged at the center of the second cone part close to the barrel part, a porous steady flow plate is arranged at the position of one third of the hollow barrel from the top, a concentrate discharge pipe is arranged at the edge of the upper part of the hollow barrel, a tailing tank is arranged at the outer edge of the hollow barrel, a self-circulation adjusting pipe and a tailing discharge pipe are arranged at the lower part of the tailing tank, and the position of the self-circulation adjusting pipe is lower than that of the tailing discharge pipe; the top of the tailing box is provided with a liquid level control gate, the lower end of a gate movable plate is connected with a fixed plate, the lower end of the fixed plate is connected between the self-circulation adjusting pipe and the tailing discharge pipe, and the tailing box is divided into a self-circulation side and a tailing discharge side;

the self-circulation regulating pipe can input tailings into a stirring barrel of a pulp stirring flow (such as a pulp stirring barrel) before a slurry pump, and the tailings enter the flotation process again through the slurry pump, so that production halt is avoided when the raw material supply is insufficient. Production stops to bring a series of reactions, brings great economic loss for the enterprise, and whole system still sustainable operation when raw materials are supplied insufficiently can be supplied from the setting of ore pulp self-loopa governing pipe, and the tailing delivery pipe is closed this moment, and self-loopa governing pipe opens, and the tailing is sent into the ore pulp stirring flow before the sediment stuff pump by the pipeline, gets into the flotation process again by the sediment stuff pump. When the raw material supply is sufficient, the self-circulation adjusting pipe is closed, the tailing discharge pipe is opened, and tailing pulp is discharged to enter the next production flow.

The liquid level control gate controls the liquid level height through lifting or lowering, and the tailing pulp overflows from the upper end of the gate and enters the tailing discharge side of the tailing tank, so that the tailing pulp is discharged from the tailing discharge pipe at the bottom. When self-circulation is needed, the control valve on the self-circulation adjusting pipe is opened, and the position of the self-circulation pipe is lower than that of the tailing discharge pipe, so that tailing pulp can be discharged from the self-circulation adjusting pipe preferentially, the requirement of self-circulation pulp is met, if the excessive pulp flow is generated, the excessive pulp flow can enter the tailing discharge side of the tailing box through the overturning overflow of the upper end of the gate and is discharged by the tailing discharge pipe, and the tailing discharge pipe is not provided with the control valve.

The liquid level is controlled by the gate to be very stable, the tailing discharge pipe discharge of the tailing tank is beneficial to the energy consumption of the ore pulp stirring tank in the next production process, the tailing tank discharges tailing ore pulp which can automatically flow into the next process flow, and power is not needed for conveying the ore pulp.

The number of the cyclone jet nozzles corresponds to the number of ore pulp outlets of the ore pulp distributor and the number of the ore pulp flotation columns;

the first ore pulp input pipe of the rotational flow jet nano cavitation bubble nozzle is connected with a slurry pump, and the first throat pipe is connected with an ore pulp inlet of an ore pulp distributor through a conveying pipeline; each ore pulp outlet is connected with a second ore pulp input pipe of one cyclone injection nozzle through a conveying pipeline, a second throat pipe of the cyclone injection nozzle is connected with the conveying pipeline, and the conveying pipeline penetrates through the side wall of the middle part of the barrel body part of one ore pulp flotation column to the center of the ore pulp flotation column and is vertically bent downwards to be inserted into the ore pulp steady flow distributor; the part of the conveying pipeline inserted into the pulp steady flow distributor is internally provided with a plurality of stator mixing and stirring impellers.

The ore pulp steady flow distributor consists of a circular bottom plate and a hollow cylinder, the diameter of the circular bottom plate is smaller than the bottom of the cylinder body part of the ore pulp flotation column, and the diameter of the hollow cylinder is smaller than that of the circular bottom plate; a plurality of rows of long round holes which are obliquely arranged are uniformly formed in the side wall of the hollow cylinder, and a round hole for a conveying pipeline to penetrate through is formed in the center of the top of the hollow cylinder.

The long round holes are balanced holes, and are used for easily crushing gas into discrete bubbles under the action of the pore plate, when the airflow is sprayed to the pore plate in a swirling mode at high speed, on one hand, most of the airflow sprayed by the swirling flow penetrates through the holes of the pore plate, so that the air beams are dispersed to generate bubbles; on the other hand, after the part of the air flow sprayed by the rotational flow hits the orifice plate, the motion aspect is changed, the air flow is rotated and folded back to the periphery, turbulence is added to the backflow, more air is entrapped, and meanwhile, the air is crushed to form bubbles.

The multi-hole flow stabilizing plate consists of a hexagonal central plate and six peripheral plates surrounding the central plate, and small holes are uniformly formed in the central plate and the peripheral plates.

Wherein the ore pulp pressure of the feeding of the slurry pump is 3MPa-10 MPa; the optimal pressure of the nanobubble ore pulp is controlled to be 4-6 MPa.

Wherein, the included angle between the pipe wall of the first ore pulp input pipe of the rotational flow jet nano cavitation bubble nozzle and the pipe wall of the first outer sleeve pipe is 13 degrees, and the outlet diameter of the first ore pulp input pipe is 0.25 times of the length of the first ore pulp input pipe; the included angle between the pipe wall of the second ore pulp input pipe of the swirl jet nozzle and the pipe wall of the second outer sleeve pipe is 13 degrees, and the diameter of the outlet of the second ore pulp input pipe is 0.25 times of the length of the second ore pulp input pipe.

The number of the first spiral flow deflectors arranged on the inner wall of the first ore pulp input pipe of the rotational flow jet nano cavitation bubble nozzle is two to four, preferably 3; the number of the second spiral flow deflectors arranged on the inner wall of the second ore pulp input pipe of the swirl injection nozzle is two to four, preferably 3.

Wherein, the ratio m of the sectional area of the first mixing chamber of the swirl jet nano cavitation bubble nozzle to the sectional area of the outlet of the first ore pulp input pipe is between 6 and 10; the ratio m of the cross section area of the second mixing chamber of the swirl injection nozzle to the outlet cross section area of the second pulp input pipe is between 6 and 10.

In the mixing chamber, the interaction between the fast flowing slurry and the surrounding entrained air is intensified, the air and slurry are thoroughly mixed, and the air is dispersed and broken into bubbles. Therefore, the mixing chamber has a significant influence on the quality of the bubbling of the bubble generator, and the structure, shape, and size of the mixing chamber are also important. In order to cut the gas into bubbles of nanometer order, the slurry flow and the air flow are subjected to intense turbulent mixing in the mixing chamber, and the more thorough the mixing, the higher the foaming rate. The length and size of the mixing chamber (generally, the ratio m (between 6 and 10) of the cross section of the mixing chamber to the outlet cross section of the pulp input pipe is used for representing an important role in the size and the dispersion degree of generated bubbles, when the diameter of the mixing chamber is smaller, turbulent mixing is violent, the size of the generated bubbles is smaller, and the dispersion degree is better, but on the other hand, when the diameter of the mixing chamber is larger, more gas is favorably sucked, and the gas content is increased.

Wherein the diameter of the outlet of the first ore pulp input pipe of the rotational flow jet nano cavitation bubble nozzle is d_nThe inlet inner diameter d of the first throat₁＝d_nm^1/2First throat length L₁7.77+2.42m, first mixing chamber length L_1.NIs 1.5d_n—2.5d_n(ii) a The diameter of the outlet of the second ore pulp input pipe of the swirl injection nozzle is d_nThe inlet inner diameter d of the second throat₁＝d_nm^1/2Second throat length L₁7.77+2.42m, second mixing chamber length L_1.NIs 1.5d_nTo 2.5d_nIn the meantime.

The invention adopts the rotational flow jet nano cavitation bubble nozzle and the rotational flow jet nozzle with the spiral flow deflector, controls the motion trail of ore pulp particles, lightens the erosion and the abrasion of the particles to the nozzle, prolongs the service life of the nozzle, simultaneously, the spiral flow deflector changes the flow form of the existing jet flow into the rotary type, and is beneficial to the improvement of the foaming performance of the rotational flow jet bubble generator. At the outlet of the ore pulp input pipe, when the rotational flow injection reaches subsonic speed, negative pressure appears at a position which is 0.2d away from the nozzle opening (d is the inner diameter of the outlet of the ore pulp input pipe), the negative pressure increases along with the increase of the fluid speed, a region from 0.2d to 4d is a maximum negative pressure region, the negative pressure region and the central axis of a rotational flow injection flow field are taken as centers, and the inflation speed (air suction quantity) is maximum when the central line of an air inlet pipe is intersected with the central line of the nozzle.

The invention is characterized in that:

1. in flotation of the flotation column, the size of bubbles is the largest factor influencing the flotation effect, and the smaller the bubbles are, the larger the bubbles are, the higher the collision probability with ore particles is, and the more favorable the separation of fine-grained minerals is. According to the theory of the action of bubbles and particles in the flotation column, if the flotation column is to realize high-efficiency flotation, the micro-bubbles are required to be generated as far as possible at a high apparent aeration rate. Because the size of the bubbles, the apparent aeration rate and the feeding rate are related, if small bubbles are generated, the low apparent aeration rate and the smaller treatment capacity are needed, and the contradiction always restricts the research of the high-efficiency flotation column and becomes an important problem to be solved by most of the existing flotation column researches. The invention adopts a cyclone jet nano-cavitation bubble nozzle and a cyclone jet nozzle to jet twice to form nano-bubbles (nano-bubbles), and the nano-bubbles are larger than or equal to 1nm and smaller than or equal to 1 mu m; the nano bubbles in the level have large specific surface area (contact angle is larger than or equal to 175 degrees), and have stronger surface activity, because the surface free energy is extremely large, the selectivity is higher than that of the common bubbles; the gas material has highly dispersed and relatively stable gas substances capable of adjusting and promoting the interaction between particles and bubbles, the promoting effect of the gas material is derived from 'nano bubble bridge capillary force' generated in the nano bubble aggregation process, the gas material can be attached to the surface of the particles, the rising speed is slow, fine particle fractions are condensed, the size of the particles is increased, and the capture probability is increased; the effect of a secondary collecting agent is achieved, and the hydrophobicity of the particle surface is improved; by promoting the adhesion of larger bubbles and particles to reinforce the flotation process, the lower separation limit of the equipment on minerals can be effectively reduced, particularly for very fine and coarse particles. The bubble amount of the nano bubbles can be directly controlled by adjusting the negative pressure air suction amount, the operation is convenient, and the dispersion is good. The invention changes the internal aeration type into the external aeration type, and replaces the original one-point aeration by multi-layer and multi-point aeration modes, thereby improving the flotation efficiency of the flotation column.

2. The formed nano bubbles can stably exist in a sodium oleate solution for more than 1 hour, and have strong stability; nanobubble size decreases with increasing sodium oleate concentration and increases with increasing pH; the electronegativity of the surface is continuously enhanced along with the increase of pH; after a certain time range is exceeded, the cavitation time is prolonged without obvious influence on the size of the nano bubbles, which is caused by the fact that dissolved gas in the solution achieves dynamic balance in a water phase and a gas phase, the nano bubbles have unique efficacy, energy is saved, the cost is low, and the quality and the efficiency are improved.

3. The ore pulp flotation column provided by the invention is a short column, and a central pump of the equipment can realize the matching of different numbers of groove bodies with six, twelve, sixteen, twenty-four and the like through an ore pulp distributor. And can flexibly switch different scales at any time according to the requirements of different mines, different ores and different processing capacities, thereby solving the great problem that the traditional flotation equipment is difficult to replace or allocate the flow.

A. High-efficiency recovery of fine-particle ore

The nano-bubble flotation column can instantly generate a large amount of nano-bubbles and can quickly capture micro-fine particles below-19 microns, so that a hydrophobic ore cluster is formed. The mineral separation recovery rate of the novel flotation column is averagely doubled compared with that of the traditional flotation machine, and is improved by more than 30 percent compared with that of a conventional flotation column for the recovery rate of fine particles;

B. high enrichment ratio

The nano bubbles form large and small bubbles which are suitable for mineralization in the rapid rising process, and gradually form a stable and thick foam layer. In the foam layer, useful minerals can be enriched at any time, so that the enrichment ratio is obviously improved compared with that of a traditional flotation column.

C. Flow simplification

Because the enrichment ratio is high, the nanobubble flotation column can replace three or even four operations of the traditional flotation machine by one process, thereby greatly simplifying the production process.

D. More stable operation

The high intelligent control enables the equipment to run more stably; intelligent control, electric control and manual control can be freely switched; the mineralization nozzles can also be quickly replaced without shutdown during operation, thereby greatly reducing maintenance efforts.

E. Low operation cost, small floor area and flexible configuration

One central pump of the device can realize the matching of different numbers of groove bodies with six, sixteen or even twenty-four. And can flexibly switch different scales at any time according to the requirements of different mines, different ores and different processing capacities, thereby solving the great problem that the traditional flotation equipment is difficult to replace or allocate the flow. (note that 70 cubic meters per tank of single tank, the effective volume of one belt twenty four is 1680 cubic meters per tank group, one belt six (70 cubic meters per tank multiplied by 6 tanks is equal to 420 cubic meters per tank group), one production line is equivalent to 15000 tons/day of handling capacity, other flotation machines and flotation columns cannot be manufactured, and the intelligent and large-scale production line of 6 ten thousand tons/day of production line can be realized by one nano bubble flotation column with one belt twenty four.

4. The ore pulp flotation column is internally provided with the flow stabilizing plate with the ordered drilled holes, so that the flow state of the ore pulp in the flotation column is improved, the problems of ' flower turning ', channeling ' and the like frequently occurring in the industrial flotation column are solved, an ideal ' plug flow ' flow state is formed, and the stability of the flow state of the ore pulp in the column, the uniformity of bubble dispersion and the like are improved.

5. The plurality of swirl jet nano-bubble nozzle devices are externally arranged, and ore is fed from the bottom, so that the energy consumption is saved; the microbubbles generated by solid-liquid gas and the ore pulp are symmetrically fed into the bottom of the main column, the high turbulence distributor device is arranged at the bottom of the main column, the bubbles and the ore pulp are in a narrow space, and the ore pulp flow stabilizing distributor is a suspected baffle plate at the center of the bottom of the main column.

The invention has the beneficial effects that:

the present invention provides a nanobubble flotation column that allows the formation of nanobubbles, increasing the flotation efficiency of mineral particles, especially for very fine and coarse particles. The equipment replaces the bubble generation modes of pressure dissolution, jet flow and the like of the traditional flotation column by 'series connection, plural number and rotational flow jet nano-bubble flotation columns', and has the characteristics of small bubble diameter, good stability, easily controlled bubble amount and the like. In the flotation of a specific model, the size of generated bubbles is independent of the apparent aeration rate and the feeding rate, and the size of the bubbles can be directly controlled by adjusting the size of the negative pressure suction capacity. Thereby well solving the problem that the nano-bubble level can not be obtained under the conditions of high apparent aeration rate and high throughput which commonly exist in a plurality of flotation columns at present.

Drawings

Figure 1A is a side view of a first preferred embodiment of a nanobubble flotation column provided by the present invention.

Figure 1B is a top view of a first preferred embodiment of a nanobubble flotation column provided by the present invention.

Fig. 2A is a schematic cross-sectional view of a swirling jet nano cavitation bubble nozzle of a first preferred embodiment of a nano bubble flotation column provided by the present invention.

Figure 2B is a schematic diagram of the pulp inlet pipe end of the swirling jet nano cavitation bubble nozzle of the first preferred embodiment of the nano bubble flotation column provided by the present invention.

Figure 3 is a side view of the slurry distributor of the first preferred embodiment of the nanobubble flotation column provided by the present invention.

Figure 4A is a cross-sectional view of a swozzle of a first preferred embodiment of a nanobubble flotation column provided by the present invention.

Figure 4B is a schematic view of the slurry inlet pipe end of the swozzle of the first preferred embodiment of the nanobubble flotation column provided by the present invention.

Figure 5A is a side view of a slurry flotation column of a first preferred embodiment of the nanobubble flotation column provided by the present invention.

Figure 5B is a perspective view of a slurry flotation column of the first preferred embodiment of the nanobubble flotation column provided by the present invention.

Figure 5C is a cross-sectional view of the slurry flotation column of the first preferred embodiment of the nanobubble flotation column provided by the present invention.

Figure 6A is a side view of a slurry flow stabilizer distributor of a first preferred embodiment of a nanobubble flotation column provided by the present invention.

Figure 6B is a top view of the pulp flow stabilizer distributor of the first preferred embodiment of the nanobubble flotation column provided by the present invention.

Figure 7A is a side view of the porous stabilizer plate of the first preferred embodiment of the nanobubble flotation column provided by the present invention.

Fig. 7B is a top view of the porous stabilizer plate of the first preferred embodiment of the nanobubble flotation column provided by the present invention.

Figure 8 is a perspective view of a slurry distributor of a second preferred embodiment of the nanobubble flotation column provided by the present invention.

Figure 9 is a perspective view of a slurry distributor of a third preferred embodiment of a nanobubble flotation column provided by the present invention.

Detailed Description

The following detailed and complete description of the embodiments of the present invention is provided to enable those skilled in the art to more easily understand the advantages and features of the present invention, and to clearly and clearly define the scope of the present invention.

Example 1

The first preferred embodiment of the nanobubble flotation column provided by the present invention, as shown in fig. 1A and fig. 1B, is composed of a slurry pump 1, a cyclone jet nanobubble nozzle 2, a slurry distributor 3, a plurality of cyclone jet nozzles 4, a flotation column and a plurality of conveying pipes 9;

as shown in fig. 2A and 2B, the swirl-jet nano cavitation bubble nozzle 2 is composed of a first outer sleeve 21, a first slurry input pipe 22, a first throat 23 and a first negative pressure suction pipe 24, wherein the first slurry input pipe 22 and the first throat 23 are respectively inserted from two ends of the first outer sleeve 21, a first mixing chamber 25 is formed between an outlet 221 of the first slurry input pipe 22, which is converged inwards, and an inlet 231 of the first throat 23, the first negative pressure suction pipe 24 is arranged at a junction of the first slurry input pipe 22 and the first mixing chamber 25, which is perpendicular to the first outer sleeve 21, and a plurality of first spiral flow deflectors 26 are arranged on an inner wall of the first slurry input pipe 22; in this embodiment, the first spiral flow deflectors 26 of the nozzle for swirling-flow-jet nano cavitation bubbles are three at 120 ° intervals.

The upper part of the pulp distributor 3 is a cylindrical barrel 31, the lower part of the pulp distributor is tapered and contracted to form a first tapered barrel part 32, the bottom end of the first tapered barrel part 32 is provided with a pulp inlet 33, the side wall of the barrel is provided with one to many circles of pulp outlets 34 along the circumferential direction, and each circle is provided with a plurality of pulp outlets 34; in this embodiment, the side wall of the tank is provided with a circle of slurry outlets 34 along the circumferential direction, and the number of the slurry outlets is 6, as shown in fig. 3.

As shown in fig. 4A and 4B, the swirl injection nozzle is composed of a second outer casing 41, a second slurry inlet pipe 42, a second throat 43 and a second negative pressure suction pipe 44, wherein the second slurry inlet pipe 42 and the second throat 43 are respectively inserted from two ends of the second outer casing 41, a second mixing chamber 45 is formed between an outlet 421 of the second slurry inlet pipe 42, which is converged inwards, and an inlet 431 of the second throat 43, two L-shaped second negative pressure suction pipes 44 are arranged at the junction of the second slurry inlet pipe 42 and the second mixing chamber 45, opposite to 180 ° of the second outer casing, and the long sides of the two second negative pressure suction pipes 44 are parallel in the same direction and are merged at the upper part; the inner wall of the second ore pulp input pipe 42 is provided with a plurality of second spiral flow deflectors 46; the second spiral deflector 46 of the swozzle in this embodiment is three at 120 ° apart.

As shown in fig. 5A to 5C, the flotation column group is composed of a plurality of slurry flotation columns 5, each slurry flotation column includes a hollow cylinder 51, the upper portion of the hollow cylinder is a polygonal cylinder 511, the lower portion of the hollow cylinder is a polygonal pyramid-shaped shrinkage cylinder 512, and a tailings discharge port 52 is opened at the bottom end of the second cone 512; a high steady flow distributor 53 is arranged at the part of the second cone part 512 close to the center of the barrel part 511, a porous steady flow plate 54 is arranged at the position of one third of the hollow barrel 51 from the top, a concentrate discharge pipe 55 is arranged at the edge of the upper part of the hollow barrel 51, a tailing tank 56 is arranged at the outer edge of the hollow barrel 51, a self-circulation adjusting pipe 561 and a tailing discharge pipe 562 are arranged at the lower part of the tailing tank, and the self-circulation adjusting pipe 561 is lower than the tailing discharge pipe 562; the top of the tailing tank is provided with a liquid level control gate 563, the lower end of the gate is connected with a movable plate 564, the lower end of the movable plate is provided with a fixed plate 565, the lower end of the fixed plate 565 is connected between the self-circulation adjusting pipe 561 and the tailing discharge pipe 562, and the tailing tank 56 is divided into a self-circulation side and a tailing discharge side;

the number of the swirl injection nozzles 4 corresponds to the number of the slurry outlets 34 of the slurry distributor 3 and the number of the slurry flotation columns 5;

the first ore pulp input pipe 21 of the rotational flow jet nano cavitation bubble nozzle 2 is connected with the slurry pump 1, and the first throat pipe 22 is connected with the ore pulp inlet 34 of the ore pulp distributor 3 through the conveying pipeline 9; each slurry outlet 34 is connected to the second slurry inlet pipe 41 of one cyclone jet nozzle 4 through a conveying pipe 9, the second throat 42 of the cyclone jet nozzle 4 is connected to the conveying pipe 9, and the conveying pipe 9 passes through the middle side wall of the barrel part 511 of one slurry flotation column 5 to the center of the slurry flotation column 5 and is vertically bent downwards to be inserted into the slurry steady flow distributor 53, and a plurality of stator mixing stirring impellers 91 are arranged in the part of the conveying pipe 9.

As shown in fig. 6A and 6B, the slurry steady flow distributor 53 is composed of a circular bottom plate 531 and a hollow cylinder 532, the diameter of the circular bottom plate 531 is smaller than the bottom of the cylindrical body 511 of the slurry flotation column 5, and the diameter of the hollow cylinder 532 is smaller than the circular bottom plate 531; a plurality of rows of long round holes 533 which are obliquely arranged are uniformly arranged on the side wall of the hollow cylinder 532, and a round hole 534 through which the conveying pipeline 9 passes is arranged at the center of the top of the hollow cylinder 532.

As shown in fig. 7A and 7B, the perforated current stabilizer 54 includes a hexagonal central plate 541 and six peripheral plates 542 surrounding the central plate, and the central plate and the peripheral plates are uniformly perforated with small holes.

The number of the swirl injection nozzles 4 corresponds to the number of slurry outlets 34 of the slurry distributor 3 and the number of slurry flotation columns 5, in this embodiment the number of slurry outlets 34 of the slurry distributor 3 is 6, and thus the number of swirl injection nozzles 4 and the number of slurry flotation columns 5 are also 6.

In this example, the slurry flotation column 5 has a height of 5.9 meters (with a bucket height of 4.7 meters and a bottom cone height of 1.2 meters) and a diameter of 6 meters.

In the second preferred embodiment, as shown in figure 8, the slurry outlet 34 ' of the slurry distributor 3 ' is provided with two circles along the side wall of the cylinder along the circumferential direction, and each circle is provided with 6 slurry outlets 34 ', and the total number is 12. Therefore, in the second preferred embodiment, the number of the swirl injection nozzles 4 and the number of the slurry flotation columns 5 are also 12.

In the third preferred embodiment, as shown in figure 9, the slurry outlet 34 "of the slurry distributor 3" is provided with three circles along the circumferential direction of the side wall of the cylinder, and each circle is provided with 8 slurry outlets 34 ", and the total number is 24. Therefore, in the third preferred embodiment, the number of the swirl injection nozzles 4 and the number of the slurry flotation columns 5 are also 24.

In the embodiment, the ore pulp pressure of the feeding of the slurry pump is controlled to be 4-6 MPa.

Wherein, the ratio of the sectional area of the first mixing chamber of the swirl jet nano cavitation bubble nozzle to the sectional area of the outlet of the first ore pulp input pipe is 8.

Example 2

The titanium flotation test of fine-grained ilmenite of Panzhihua was carried out using the nanobubble flotation column of the first preferred embodiment provided in example 1, which was suitable for the flotation tailings of a titanium separation plant. After 72-hour industrial tests, the good indexes that when the feeding grade is 6.55%, the concentrate grade is 47.75%, the tailing grade is 4.83%, the yield is 4.01%, the recovery rate is 29.21%, and the cost of the flotation reagent is 108.03 yuan/ton concentrate are obtained.

The nano bubble flotation column provided by the invention has the remarkable characteristics of high recovery rate, high enrichment ratio, high sorting speed and the like. Under the condition of poor mineral composition, impurity and wide mineral distribution, TiO can be separated by using one coarse and three fine processes₂Flotation tailings with the grade being low by about 6.5 percent are sorted to 47 percentThe above.

The nanobubble flotation column provided by the invention has strong adaptability to raw ore grade fluctuation. By flotation of TiO from the raw ore₂When the grade is controlled to be more than 4.5 percent, the qualified titanium concentrate products can be stably and better sorted by the nano-bubble flotation column provided by the invention.

The nanobubble flotation column provided by the invention solves the problem that flotation tailings with low valuable mineral grade, which cannot be effectively recycled in the existing titanium separation plant, are recycled again, and can improve the resource utilization rate to the maximum extent.

Example 3

The second preferred embodiment of the nanobubble flotation column provided in example 1 is adopted to carry out industrial production on the strong-magnetic rough concentrate magnetizing roasting-weak magnetic separation tailings and the strong-magnetic middling flotation rare earth tailings in the ladle steel concentration plant: the mixed flotation concentrate obtained by pre-decarbonization and mixed flotation of the low-intensity magnetic separation tailings is subjected to a full-flow flotation test of primary roughing, tertiary concentration and primary scavenging, and a high-grade rare earth concentrate product with the yield of 3.24%, the REO grade of 63.41% and the recovery rate of 25.13% can be obtained.

The product in the rare earth tailings groove is subjected to a full-flow flotation test of primary roughing and four-time concentration to recover niobium minerals, and the final yield is 20.59 percent and Nb ₂0₅The grade is 0.45%, and the recovery rate is 46.12%.

Example 4

The results of the industrial production of the lead-zinc separation plant of the dam division of the beijing binong mining company using the third preferred embodiment of the nanobubble flotation column provided in example 1 demonstrate that:

by adopting a process flow and a medicament system of a conventional medicament, namely rough scanning, fine scanning and secondary fine scanning, and applying a rotational flow spraying nano mineralizing flotation column to separate the flotation tailing pulp of the lead-zinc ore of the factory dam of the Gansu silver company, the industrial test obtains good indexes: the quality of the lead-zinc concentrate is 30.04%, the metal recovery rate reaches 44.25%, and the production profit can be obtained from 1312 ten thousand yuan each year.

The nano bubble flotation column equipment has stable and reliable operation and simple and convenient operation (the main operation is only to adjust the liquid level of ore pulp through a flotation flashboard); the negative pressure has large air suction amount, can generate sufficient air amount to increase the combination chance of minerals and foams, and is beneficial to the flotation of the minerals; the thickness and area of the foam layer are much larger than those of the common flotation machine, and the high enrichment ratio is ensured. Ensuring high recovery rate.

The nano-bubble flotation column is used for single-groove separation of factory dam zinc raw ore, and compared with a common jet flotation machine, the operation recovery rate can be improved by about 35 percent.

The product analysis result and the crude ore size fraction analysis show that the nanobubble flotation column effectively recovers coarse particles and fine particles in the tailings.

As can be seen from the above examples, the nanobubble flotation column provided by the present invention has excellent performance in terms of recycling of low-grade coarse-grained, fine-grained embedded minerals, and reducing the content of magnesium oxide in the concentrate.

Example 5

By adopting the first preferred embodiment of the nanobubble flotation column provided by the embodiment 1 to carry out industrial re-flotation on Gansu Jinchuan copper-nickel tailings, the scale is 2000 tons/day, the process flow and the medicament system of the conventional medicament are adopted, when the feeding grade nickel is 0.274% and the copper grade is 0.30, the obtained nickel concentrate grade is 3.153% and the copper grade is 2.48%, the recovery rate of feeding is 14.86% and the copper is 6%, and the recovery rate of raw ore is improved by 2.06%, so that a good index is obtained.

The recycling of the tailings can not only improve the ecological environment problem caused by the stockpiling of the tailings, but also enlarge the resource utilization range. In addition, the recovery of metal in tailings can bring huge economic benefits, 31000 tons of tailings are treated daily, the annual production is calculated within 330 days, more than 3800 tons of nickel can be produced annually according to the assessment indexes of projects, only one item of nickel is recovered from the tailings, namely the annual production increase value is about 5.7 million yuan, and the profit is more than 2.6 million yuan.

According to the embodiment, the nanobubble flotation column provided by the invention can effectively improve the flotation efficiency and the tailing recovery rate through the generation of nanobubbles, the design of an ore pulp flotation column and the like, and brings good production benefits to enterprises.

Claims

1. A nanometer bubble flotation column is characterized by comprising a slurry pump, a rotational flow jet nanometer cavitation bubble nozzle, a slurry distributor, a plurality of rotational flow jet nozzles, a flotation column and a plurality of conveying pipelines;

the cyclone jet nozzle consists of a second outer sleeve, a second ore pulp input pipe, a second throat pipe and a second negative pressure air suction pipe, wherein the second ore pulp input pipe and the second throat pipe are respectively inserted from two ends of the second outer sleeve, a second mixing chamber is formed between an outlet of the inward convergence of the pipe wall of the second ore pulp input pipe and an inlet of the second throat pipe, two L-shaped second negative pressure air suction pipes are arranged at the pipe wall of the second ore pulp input pipe and the second outer sleeve at the junction of the second mixing chamber in an opposite 180-degree manner, the long edges of the two second negative pressure air suction pipes are parallel in the same direction and are converged into a converging pipe at the upper part, and an air suction pipe valve is arranged on the converging pipe and used for controlling the air suction amount; the inner wall of the second ore pulp input pipe is provided with a plurality of second spiral flow deflectors;

the flotation column group consists of a plurality of pulp flotation columns, each pulp flotation column comprises a hollow cylinder, the upper part of the hollow cylinder is a polygonal cylinder body, the lower part of the hollow cylinder body is in a polygonal pyramid shape and shrinks to form a second cone cylinder part, and the bottom end of the second cone cylinder part is provided with a coarse particle tailing discharge pipe; a high steady flow distributor is arranged at the center of the second cone part close to the barrel part, a porous steady flow plate is arranged at the position of one third of the hollow barrel from the top, a concentrate discharge pipe is arranged at the edge of the upper part of the hollow barrel, a tailing tank is arranged at the outer edge of the hollow barrel, a self-circulation adjusting pipe and a tailing discharge pipe are arranged at the lower part of the tailing tank, and the position of the self-circulation adjusting pipe is lower than that of the tailing discharge pipe; the top of the tailing tank is provided with a liquid level control gate, the lower end of the gate is connected with a movable plate, the lower end of the movable plate is provided with a fixed plate, the lower end of the fixed plate is connected between the self-circulation adjusting pipe and the tailing discharge pipe, and the tailing tank is divided into a self-circulation side and a tailing discharge side;

2. The nanobubble flotation column of claim 1, wherein the slurry flow stabilizer distributor consists of a circular bottom plate having a diameter smaller than the bottom of the body of the slurry flotation column and a hollow cylinder having a diameter smaller than the circular bottom plate; a plurality of rows of long round holes which are obliquely arranged are uniformly formed in the side wall of the hollow cylinder, and a round hole for a conveying pipeline to penetrate through is formed in the center of the top of the hollow cylinder.

3. The nanobubble flotation column of claim 1, wherein the perforated stabilizer is comprised of a hexagonal central plate and six peripheral plates surrounding the central plate, the central plate and the peripheral plates being uniformly perforated with small holes.

4. The nanobubble flotation column of claim 1, wherein the slurry pressure of the feed of the slurry pump is 3MPa to 10 MPa.

5. The nanobubble flotation column of claim 4, wherein the slurry pressure of the feed of the slurry pump is 4MPa to 6 MPa.

6. The nanobubble flotation column according to claim 1, wherein the angle between the wall of the first slurry inlet pipe of the jet-swirling nanobubble nozzle and the wall of the first outer sleeve is 13 °, and the diameter of the outlet of the first slurry inlet pipe is 0.25 times the length of the first slurry inlet pipe; the included angle between the pipe wall of the second ore pulp input pipe of the swirl jet nozzle and the pipe wall of the second outer sleeve pipe is 13 degrees, and the diameter of the outlet of the second ore pulp input pipe is 0.25 times of the length of the second ore pulp input pipe.

7. The nanobubble flotation column of claim 1, wherein the number of the first spiral flow deflectors arranged on the inner wall of the first slurry input pipe of the cyclone jet nanobubble nozzle is two to four; the number of the second spiral flow deflectors arranged on the inner wall of the second ore pulp input pipe of the swirl injection nozzle is two to four.

8. The nanobubble flotation column according to claim 1, wherein the ratio m1 of the cross-sectional area of the first mixing chamber of the swozzle nanobubble nozzles to the cross-sectional area of the outlet of the first slurry inlet pipe is between 6 and 10; the ratio m2 of the cross-sectional area of the second mixing chamber of the swirl injection nozzle to the outlet cross-sectional area of the second slurry inlet pipe is between 6 and 10.

9. The nanobubble flotation column of claim 8, wherein the exit diameter of the first slurry inlet pipe of the swozzle nanobubble nozzle is d_n1The inlet inner diameter d of the first throat₁＝d_n1m1^1/2First throat length L₁7.77+2.42m1, first mixing chamber length L_1.NIs 1.5d_n1—2.5d_n1(ii) a The diameter of the outlet of the second ore pulp input pipe of the swirl injection nozzle is d_n2The inlet inner diameter d of the second throat₂＝d_n2m2^1/2Second throat length L₂7.77+2.42m2, second mixing chamber length L_2.NIs 1.5d_n2To 2.5d_n2In the meantime.