Hematite is a kind of iron trioxide (Fe2O3) without crystal water. Hematite ore contains 35% to 40% iron, the hardness is between 5.5 and 6.5, and the specific gravity is between 4.8 and 5.3. This kind of iron ore is weak magnetic iron ore.
At present, there are three common hematite beneficiation processes: gravity separation, magnetic separation and flotation.
Hematite gravity separation method can be divided into single gravity separation method and spiral chute-shaking table combined gravity separation method according to the mineral properties.
Single gravity separation method：
According to the mineral particle size conditions, single gravity separation method can be divided into fine grain gravity separation and coarse grain gravity separation.
Among them, fine grain gravity separation is to grind the crushed iron ore to dissociate its monomers, and then pass it through gravity separation to obtain fine-grained high-grade hematite concentrate. This method is suitable for hematite with fine embedded particle size and high magnetic content.
The coarse-grained gravity separation method mostly only crushes, but not grinds the mineral, because the mineral particle is coarse. Then we use gravity separation to discard the crushed coarse tailings. This method is suitable for coarse-grained embedded hematite ore.
Spiral chute-shaking table combined gravity separation method:
Mainly suitable for processing medium and fine-grained hematite. The spiral chute can be used for roughing first, and then the rough concentrated iron ore can be beneficiated by the shaking table.
1. Spiral Chute
The spiral chute is based on the different specific gravity of the different iron minerals. After the slurry is fed, the minerals are settled according to the specific gravity by the combined action of water flow, mineral gravity, and the friction force of the ore particles and the bottom of the tank, and are distributed in different areas in the tank. It runs vertically inside and completes stratification by the flow velocity of water. Among them, the ore particles with smaller specific gravity are thrown to the outer edge in the rotary motion, and the ore particles with large specific gravity move on the inner edge of the tank.
2. Shaking Table
According to the density and particle size of iron minerals, the driving motor is used to make the bed surface do longitudinal reciprocating motion, with the asymmetric reciprocating motion of the creation surface and the comprehensive effect of thin sloping water flow, so that the ore particles are fan-shaped distribution on the bed surface to achieve separation.
The shaking table has high separation accuracy, and is widely used in seaside sand mines and the minerals use weak magnetic separation. The separation particle size range is 2~0.037mm, the equipment is reliable, the distribution of mineral belts is clearly visible, and it is easy to manage.
3. Jig
Jig machines are generally suitable for various iron ore pre-selection tailing-throwing operations in iron ore dressing plants, and their suitable size range for sorting is more than 3 mm. The jig has simple structure, large processing capacity, simple operation and strong adaptability.
4. Centrifugal Concentrator
Centrifugal concentrators are suitable for processing relatively fine-grained iron minerals in iron ore beneficiation plants, such as the target minerals recovered from sand ore and the target minerals recovered from the grinding and grading circuit of the beneficiation plant. The separation particle size range is 0.074~ 0.01mm. The machine has simple structure and strong processing ability.
The hematite magnetic separation method is mainly suitable for the treatment of hematite ore containing non-metallic minerals. When the pulp enters the separation stage, the magnetic ore particles can be magnetized under the action of a non-uniform magnetic field. The attraction of the magnetic field makes it adsorbed on the cylinder and brought to the ore end for discharge, while the non-magnetic ore gravel still exists in the slurry due to the small effect of the magnetic field.
Wet magnetic separator
Wet magnetic separator uses magnetic separation method to directly sort hematite ore in a magnetic field of more than 10,000GS, which can effectively separate useful minerals and veins in the ore, and make various coexisting useful minerals separate from each other as much as possible, and remove or reduce harmful impurities to obtain the raw materials needed for smelting or other industries in the process.
This process is of great significance for saving energy and reducing consumption, effectively utilizing extremely lean iron ore and improving the quality of final iron concentrate.
The wet magnetic separator has the advantages of small power consumption, light and easy to drag the whole machine, large processing capacity, good separation effect, good concentrate grade, simple process, low cost, energy saving and environmental protection.
Hematite flotation methods are mainly two types: positive flotation and reverse flotation.
The hematite positive flotation method is suitable for treating single hematite, and mainly uses anionic collectors to float the hematite from the raw ore.
The hematite reverse flotation method is suitable for hematite with high grade and easily floating gangue. It mainly uses anionic and cationic collectors to float the hematite from the raw ore.
1. Mechanical Stirring Flotation Machine
Mechanical stirring flotation machine is an air self suction flotation machine, which mainly relies on mechanical stirrer (rotating from and stator) to achieve the inflating and stirring of the pulp, which can self-absorbing air and self-absorbing pulp, without external aerating device, and the middle ore return without pump transmission.
The equipment commonly used in hematite ore beneficiation are SF type mechanical strring flotation machine, JJF type mechanical stirring flotation machine and BF type mechanical stirring flotation machine.
2. Inflatable Stirring flotation machine
The inflatable stirring flotation machine is a kind of flotation machine with external air supply, which mainly relies on the mechanical stirrer to stir the pulp and the blower to inflate. This type of flotation machine cannot absorb air by itself. It needs a pump to transport the pulp when the middling returns. In addition, special air supply equipment is also required.
Commonly used equipment in hematite beneficiation are XCF inflatable flotation machine, KYF inflatable flotation machine and XCF-KYF flotation unit.
The three kinds of hematite beneficiation processes and the commonly used hematite beneficiation equipment have been introduced above. Xinhai is a professional beneficiation service provider, which can provide customers with beneficiation technology and beneficiation equipment. If you have any related request, please contact our online customer service.
