Concentration of minerals
1. Flotation Systems
Flotation systems are one of the mineral concentration methods that are used for iron ore, copper sulfide and etc. In these systems minerals are crushed into suitable particle size and also wet milled. The mineral suspension enters hydrocyclone and large size particles will return to mill system. Flotation process is done by adding frothers, collectors and other minerals in flotation cells. After the suspension passed flotation cells separation of solids and water will be done in thickener and filter press. The output concentrated material often contains 5 to 10 percent that can be sent to dryer kilns if it needs and then sent to processing units.
2. Magnetic Separation
Magnetic Separation are used for minerals with magnetic properties mostly magnetite iron ores. In this method minerals with magnetic properties will separated when are passing through magnetic field. The separation is done in both dry and wet method and with different magnetic field intensities. Paramagnetic materials can be separated in high intensity fields and ferromagnetics are separated in low density fileds.
3. Gravity SeparationIn
gravity separation methods difference in density play the major role in separation of gauge and main minerals. Rare metals, coal, iron ores and many other minerals are concentrated with gravity separation method. The process is based on minerals behavior in watery media. Minerals are crushed into fine size before separation and it can be done both dry or wet. In new methods for gravity separation centrifuge force is used.
4. Pre Reduction
Using pre reduction process causes concentration of minerals. Pre reduction is done in different types of kilns such as rotary or vertical ones and in suitable process conditions for several minerals like manganese, molybdenum, chrome and other minerals. In this process reduction is incomplete and the mineral will be prepared for next mineral processes.