Iron ore beneficiation involves a series of physical and chemical processes to extract and refine containing mineral iron from raw ore. The process begins with the mining of iron ore, which can be in the form of oxide or sulfide ores.
Once the raw ore is mined, it is crushed and screened in some cases a concentration via sensor sorters, dry magnetic separators or jigs applied. The ore is then grind into fine particles depending on the liberation size, which is done using various types of grinding mills such as ball mills, rod mills, tower mills or autogenous mills.
The ore is then subjected to magnetic separation to separate the iron containing mineral particles such as magnetite and hematite from the non-magnetic particles. This is done using magnetic separators such as drum separators, wet high-intensity magnetic separators, or electrostatic separators. The magnetic concentrate is then further refined using a process called flotation, which involves adding chemical reagents to the concentrate selectively separate the impurities such as silicates and sulphides.
After flotation, the concentrate needs to be dewatered to reduce the moisture content and improve the efficiency of subsequent processing steps. Different kind of filters are is used to separate the solid and liquid components of the concentrate. The solid component, or filter cake, is retained on the filter cloth, while the liquid component, or filtrate, passes through the cloth and is collected to recycled back to the process so that the plants work usually with no liquid discharge to the environment.
It is then sent to a dryer to remove any remaining moisture. The dryer can be a rotary dryer, which uses hot gases to dry the material, or a flash dryer, which uses high-velocity hot air to dry the material.