Types of Flotation Machines

A flotation machine is the abbreviation of floating concentrator, referring to the flotation process equipment. The flotation machine is essential equipment in mineral processing, designed to separate valuable minerals from gangue through froth flotation. Here, we examine the three primary types: mechanical agitation, aerated agitation, and inflatable (column) flotation machines, highlighting their working principles and key characteristics.

Primary Types of Flotation Machines

The aeration and agitation of the slurry are completed by the impeller and mechanical agitation device of the flotation machine. It belongs to the external gas self-priming flotation machine, generally the upper gas suction type, that is, air is inhaled near the mechanical stirring device in the lower part of the flotation tank.

This kind of flotation machine can not only self-prime air, but also self-prime slurry. It is easy to realize self-flow when returning the ore middlings, has less auxiliary equipment, neat equipment configuration, simple operation and maintenance, etc. But this type of machine has small inflation and high power consumption.

In summary, the mechanical agitating flotation machines are the most widely used flotation machine among all types.

As the impeller rotates, the slurry in the tank is sucked from the bottom of the tank through the lower end of the impeller to the impeller vane. At the same time, the low-pressure air fed by the blower enters the air distributor through the hollow shaft and the impeller.
After the slurry and air are thoroughly mixed between the impellers, they are pushed out obliquely from the periphery of the upper half of the impeller, and the stator is stabilized and oriented to enter the entire trough.
The bubble rises to the foam stabilization zone. After the enrichment process, the foam overflows from the overflow weir and enters the foam tank. A part of the slurry flows to the lower part of the impeller, and then is stirred by the impeller to remix to form mineralized bubbles, and the remaining slurry flows to the next trough until it eventually becomes tailings.

Advantages

• Strong stirring force can ensure the suspension of mineral particles with large density and large particle size, and can promote the dispersion and emulsification of insoluble chemicals.
• For the complex process of sorting polymetallic ore, self-priming can rely on the suction of the impeller to achieve the return of the mine, eliminating the need for a large sand pump.
• When it is difficult to select and complex ore or hope to obtain a high-grade concentrate, it can guarantee a better stability index.
• The moving parts have high speed, high energy consumption, serious wear, and large maintenance.

Disadvantages

• A large amount of inflation is easy to adjust, which is beneficial to increase production and adjust the process.
• The stirring does not work, so the speed is low, the wear is small, the energy consumption is low, and the maintenance is small.
• The liquid level is stable, the mineral mud is less, and the sorting index is good, but the gas pressure system and pipeline are needed.

The agitation device of the aerated agitation flotation machine only functions to agitate the slurry and distribute the airflow. The air is mainly pressed into the slurry by an external fan, and the aeration and the agitation are separated.

The air is supplied by the external blower, and the amount of inflation can be adjusted by the valve according to the needs of the flotation.
Since the impeller only acts as a stirring force, the rotation speed is low, the stirring is not strong, and the flotation of brittle minerals is not easy to produce mud. The slurry surface is relatively stable, and it is easy to form a stable foam layer, which is conducive to improving the selection index.
The impeller rotates at a low speed, the slurry flows by gravity, the unit consumes less electricity, the service life is longer, and the equipment maintenance cost is also low.

Such flotation machines are CHF-X type, XJC type, BS-C type, KYF type, BS-K type, LCH-X type, CLF type, and the like.

When the impeller rotates, the slurry in the tank is sucked into the impeller blade from the bottom of the tank through the bottom of the tank from the lower end of the impeller. At the same time, the low-pressure air fed by the blower enters the impeller chamber through the air duct, the air regulating valve, and the hollow main shaft, and the slurry and air are in the impeller blade. After being thoroughly mixed, it is discharged from the periphery of the upper half of the impeller, and the discharged ore flow moves obliquely upward. After being stabilized and oriented by the stator installed obliquely above the impeller, it enters the entire trough.

The mineralized bubbles rise to the surface of the trough to form a foam. The foam flows into the foam tank, the slurry is returned to the impeller area for recycling, and the other part is re-selected through the flow holes in the inter-groove wall.

The gas required for flotation of the aerated mechanical agitation flotation machine is mainly forcibly fed by an external force (blower), which is characterized by a large adjustment range of the inflation amount and accurate adjustable size, which is particularly suitable for a large amount of inflation. The flotation of minerals with the large-scale flotation machine consumes less total power than self-inhalation, making it easy to optimize the design and operation.

Advantages

• DC tank design, the pulp passing capacity is large, and the flotation speed is fast;
• The centrifugal blower (pressure is 0.245kg/cm2) is used for gas supply, and the amount is adjusted within a certain range according to the process requirements;
• Small footprint, lightweight per unit volume;
• The ore particles are suspended in the tank, which reduces the deposition and stratification of coarse particles in the tank, and can increase the upper limit of the floatable particle level;
• The impeller is only used to recycle the slurry and the dispersed air. The impeller of the deep tank flotation machine can still work at low speed, so the spare parts wear and energy consumption is low, the energy consumption is low, and the mineral liquid surface is relatively stable. Conducive to the enlargement of equipment and increasing production capacity;
• The axial and radial clearance between the impeller and the cover is larger than that of the A-type flotation machine, and it is easy to install and adjust;
• The drug and energy consumption were significantly reduced, and the selection index was improved.

Disadvantages
The disadvantage of this type of flotation machine is that the foam (middle mine) cannot be returned, and a foam pump (which can also be provided by a suction tank) is required. And the configuration can not be in the same plane, requiring a stepped configuration. This machine is suitable for rough and scavenging operations of large and medium-sized flotation plants.

The flotation column has the advantages of a simple structure and easy manufacture. The disadvantage is that there is no agitator, and the flotation effect will be affected to some extent. The aerator is prone to forming calcium, which is not conducive to air dispersion.
With the re-emergence and successful application of foreign flotation column technology, China has developed several flotation columns for industrial production. The flotation column is suitable for the rough selection and scavenging operations of the easy-to-select ore, which is composed of simpler and higher grades.

Inflatable flotation machines use a vertical circulation of slurry and sufficient low pressure air to increase the efficiency of the selection. The vertical circulation of the slurry in the flotation tank produces an upflow, which eliminates the occurrence of stratification and grit in the flotation machine, increases the possibility of sorting coarse and heavy minerals, and helps the ore and bubbles collide.

When the impeller rotates, the slurry in the impeller chamber is mixed with the air and then thrown out, so that the back surface of the impeller blade becomes a negative pressure zone, and the circulating slurry enters the negative pressure zone through the annular hole between the circular cylinder and the bell.

The low-pressure air enters the impeller chamber sealed by the circulating slurry, which promotes the thorough mixing of the air and the slurry in the impeller chamber. The mixture is smashed on the cover blade by the centrifugal force generated by the rotating impeller and further disperses and disperses the air bubbles. In the slurry, under the action of the vertical circulating upflow, the bottom of the entire trough is diffused upward, so that the foam is separated from the gangue mineral in the calm zone above the trough, and the useful mineral is selected into the foam product.

The inflating action of the flotation machine is not to draw air into the tank by the negative pressure zone generated by the rotating impeller, but to supply air to the impeller chamber through the central cylinder by a blower. The aeration efficiency is mainly related to the amount of aeration and the amount of pulp circulating through the impeller. The amount of inflation can be adjusted as needed, and the maximum inflation can reach 1.5~1.8 m3/(m2·min).

Because this flotation machine does not need to generate negative pressure suction, its impeller speed is low. Therefore, the motor power can be small, the power consumption is reduced, and mechanical wear is reduced. Many large flotation machines developed at home and abroad are inflated mechanical mixing types.

Advantages

• Simple structure, convenient manufacturing and maintenance, low investment and low operating cost;
• Creates suitable dynamic collision of bubbles and particles and static separation of bubbles and particles, which is conducive to fine-grain classification;
• Can introduce other force fields, strengthen sorting, foam thickness, bubble size, and quantity adjustment;
• The flotation speed is fast, the process is simplified (one operation is equivalent to the flotation machine several operations);
• Large enrichment ratio, high recovery rate, and large processing capacity, especially suitable for processing fine particle size and easy to control and enlarge.

Disadvantages
The disadvantage of the flotation column is that the particles are difficult to suspend, and the probability of contact between the bubbles and the particles is small. In order to improve the recovery rate of the grade loss, it is generally used for rough selection and sweeping operations, and the self-flow configuration is complicated.
The bubble generator has an external and built-in method, and the bubble generator is easily fouled and inconvenient to replace in high-alkalinity slurry.

Flotation Machine For Sale

Looking for high-performance flotation machines? We offer a wide range of models, including mechanical, aerated, and column flotation cells, suitable for various minerals like gold, copper, lead, zinc, and coal.

Available Models & Features

Mechanical Agitation Flotation Machines
Models:  XJK, SF, and JJF series
Capacity: 0.5–300 m³ per cell
Applications: Bulk flotation, roughing/scavenging

Aerated Agitation Flotation Machines
Models:  KYF, XCF, and CLF series
Capacity: 5–200 m³ per cell
Key Benefits: Lower power consumption, precise air control

Flotation Columns (Inflatable Type)
Capacity: 5–500 m³ per unit
Key Benefits: High recovery for fine particles, modular design