Iron ore flotation is mainly the process of separating useful minerals (iron ore) by reagents according to the difference of physical and chemical properties of the mineral surface. The main iron ore processing equipment is the flotation machine. It can be divided into mechanical agitation flotation cells and air inflation agitation flotation cells.
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Mechanical agitation flotation cell is the air self-suction iron ore flotation processing equipment. It mainly relies on a mechanical agitator (rotor and stator) to realize the aeration and agitation of pulp. It can self-suction air, self-suction pulp, no external air charging device, meddlings can be returned without the pump. The equipment commonly used in iron ore beneficiation includes SF mechanical agitation flotation cell, JJF mechanical agitation flotation cell, and BF mechanical agitation flotation cell.
SF mechanical agitation flotation cell is composed of tank body, impeller, cover plate, center cylinder, feed pipe, air suction pipe, middling pipe, motor, bearing body, big pulley, and other parts.
When working, the pulley is driven by the motor to make the impeller rotate. Under the action of the impeller rotation, the pulp in the impeller cavity generates centrifugal force and is thrown around, so that a negative pressure area is formed in the impeller cavity. On the one hand, enough air is sucked in to mix with the pulp. On the other hand, the pulp is mixed with the reagents. And the foam is refined so that the mineral attaches to the foam and floats to the pulp surface to form mineralized foam.
SF mechanical agitation flotation cell is mostly used for roughing and scavenging operations in iron processing plants and is widely used in medium and large plants.
JJF mechanical agitation flotation cell is composed of tank body, impeller, cover plate, fake bottom, real bottom, beam, diversion bucket, vertical cylinder, dispersion cover, motor, bearing, big pulley, and other parts. The pulp in the tank of the JJF flotation cell can form a large circulation in the lower part, and can air self-suction, but not slurry self-suction. During the operation, the middling ore return needs to be transported by the pump.
When the JJF mechanical agitation flotation machine is working, vortexes are generated in the vertical tube and the diversion tube. This vortex forms a negative pressure and sucks the air from the air inlet pipe. In the impeller and stator area, it is mixed with the slurry sucked in through the diversion tube. The slurry-gas mixed flow is moved in a tangential direction by the impeller, and then converted into radial movement by the action of the stator, and is evenly distributed in the flotation cell. The mineralized bubbles rise to the froth layer and are scraped out unilaterally or bilaterally to form froth products.
JJF mechanical agitation flotation cell is rarely used in the iron ore processing plant and is mostly used in metal ores and non-metallic minerals that require a wide range of gas content such as copper and molybdenum.
The structure of the BF mechanical agitation flotation cell is basically the same as that of the SF type. It can self-suction slurry from outside the tank. When working, the negative pressure area is formed in the center of the upper and lower blades of the impeller as the impeller rotates. The air is sucked in by the air suction tube and enters the upper impeller cavity through the central cylinder. The pulp is sucked into the impeller cavity from the groove by the lower blade of the impeller. After the slurry and gas are mixed, mineralized bubbles are formed to float up.
BF mechanical agitation flotation cells are mostly used for roughing operations in medium and small iron ore processing plants.
The air inflatable agitation flotation cell belongs to the external air supply flotation machine, which mainly relies on the mechanical stirrer to stir the pulp and the blower to inflate.
This type is not the air self-suction flotation machine. When the middlings return, this type of flotation machine needs a lift pump to transport the pulp and special air supply equipment to suck in air.
The equipment commonly used in iron ore beneficiation includes XCF air inflation agitation flotation cell, KYF air inflation agitation flotation cell, XCF-KYF flotation unit, and CLF coarse particle flotation cell.
XCF air inflation agitation flotation cell is composed of tank body, connecting pipe, ore feeding pipe, middling pipe, impeller cover, bearing, motor, and other parts.
This flotation machine is different from the conventional inflatable flotation machine, which can suck in the slurry by itself.
During operation, the motor drives the impeller to rotate, and the low-pressure air is fed by the blower, enters the air distributor through the hollow main shaft, and enters between the impeller blades through the holes in the sidewall of the distributor. After that, the mineralized foam rises to the surface of the pulp.
XCF air inflation agitation flotation cells are mostly used for roughing and scavenging operations in medium and large iron ore concentrators.
KYF air inflation agitation flotation cell is composed of tank body, impeller, stator, suction pipe, air distributor, motor, bearing, etc. The pulp and air of the flotation machine are fed by external devices.
During operation, after the impeller rotates, the pulp in the tank is thrown around by the impeller and enters between the impeller blades through the lower end of the impeller.
The low-pressure air is fed by the blower and distributed between the impeller blades. When the slurry and air are fully mixed, they are discharged from the upper half of the impeller. After being stabilized by the stator, the air and slurry enter the groove to form mineralized foam and float up.
KYF air inflation agitation flotation cell is mostly used for processing relatively single iron ore and is commonly used for roughing and scavenging operations in iron ore beneficiation plants.
CLF coarse particle flotation cell is composed of tank body, impeller, stator, steady flow plate, hollow shaft, air distributor, motor, bearing, etc. The impeller blade speed ratio of this flotation machine is high.
When working, after the impeller rotates, the air is fed by the blower and fed to the impeller blades by the hollow shaft and the air distributor. The pulp is inhaled from the lower part of the impeller to the impeller blades, fully mixed with the air, and discharged from the upper part of the impeller, through the steady flow plat and the lattice plate, into the upper area of the groove.
At this time, the inside of the flotation machine contains a large number of air bubbles, while the outer circulation channel contains no air bubbles or a very small amount of air bubbles, forming a pressure difference, and under the action of this pressure difference and the suction of the impeller, the internal pulp and air bubbles rise through the grid plate, bring the coarse-grained minerals to the top of the grid plate to form a suspended layer, the mineralized foam and the pulp containing finer mineral particles continue to rise, and the mineralized foam rises to the liquid surface to form a foam layer.
CLF type coarse-grain flotation machine is mostly used in iron ore beneficiation plants to handle coarse-grained mineral separation (at the same time, it can handle the fine-grained mineral separation as well).
As an important iron ore processing equipment, the flotation machine is widely used in iron ore plants. Different iron ores have different properties and should use different flotation processes, so the flotation equipment and flotation reagents are also different.
In the actual iron ore processing plant, we should do mineral processing tests to obtain ideal indicators. With the test results, we can scientifically and rationally design the mineral processing process, iron ore processing equipment, and reagents to obtain an ideal return on investment.