Hematite is a kind of weak magnetic iron ore. It contains single hematite, polymetallic hematite and siderite-magnetite mixture.
For single hematite:
1. Roasting magnetic separation
Roasting magnetic separation is one of valid methods to separate fine from ultrafine particles (below 0.02mm). When the components are complicated and other beneficiation methods fail to meet related indicators, it is strongly recommended.
2. Gravity separation, floatation, strong magnetic separation and combined process
Floatation is common when separating fine from ultrafine hematite. There are two manners --- direct floatation and reverse floatation. Gravity separation and strong magnetic separation are more suitable for the separation of coarse particle (2-20mm).
The use of specific beneficiation method and combined use shall observe types of ores.
For polymetallic hematite:
1. The polymetallic hematite mainly refers to hydrothermal or sedimentary hematite and siderite which contains potassium and sulfide. This kind of ores usually adopts gravity separation, floatation, strong magnetic separation or combined separation methods to recycle the iron. Flotation is recommended to recycle the potassium and sulfide.
For siderite -magnetite mixture:
1. Single siderite -magnetite mixture
This kind of mineral has two separation methods. One is combined use of weak magnetic separation, gravity separation, floatation and strong magnetic separation where weak magnetic separation is responsible for recycling the magnetic iron ore while other methods are responsible for recycling the iron ore having weak magnetism. The other is the combining process of roasting magnetic separation and other separation methods.
2. Polymetallic siderite -magnetite mixture
The beneficiation method is complicated. Generally, weak magnetic separation and other separation methods would be connected to perform beneficiation.