Minerals magnetic separation

The treatments used to recover nickel from its sulfide and lateritic ores differ considerably because of the differing physical characteristics of the two ore types. The sulfide ores, in which the nickel, iron, and copper occur in a physical mixture as distinct minerals, are amenable to initial concentration by mechanical methods, eg, flotation (qv) and magnetic separation (see SEPARATION,MAGNETIC). The lateritic ores are not susceptible to these physical processes of beneficiation, and chemical means must be used to extract the nickel. The nickel concentration processes that have been developed are not as effective for the lateritic ores as for the sulfide ores (see also Metallurgy, extractive Minerals recovery and processing). 

H. Hadey-Smith, Magnetic Separation in MineralBeneficiation, Metals and Minerals International. 

Marston Sala high-gradient magnetic separator Electromagnet, SI 1 percondi icting 20,000 50,000 Steel wool, expanded metal, steel halls 25x Itf Strongly to very weakly 0.0001-2 Iron ores, industrial minerals, coal, liquefied coal, wastewaters, purifiers, catalyst recovery, chemical industry... 

If the ore consists of separate grains containing the desired material, it can be separated from undesired minerals by physical methods such as flotation, sedimentation, or magnetic separation. For metals this step can lead to 80 to 95 percent concentration of the value of the ore. Ceramic raw materials such as sand and clay can often be found pure enough in nature so that no concentration is needed. 

All minerals in some way or the other are influenced by an external magnetic field although the degree of this response varies widely. Based on different response of different minerals in external magnetic field minerals have been classified into different groups that have essentially to development of an important physical separation method called magnetic separation which has been described quite in detail in the next chapter on mineral processing. Present topic is, therefore, not pursued any further. 

When ores are mineralized in such a way that discrete grains of valuable minerals are contained in a matrix of gangue minerals, physical concentration methods such as flotation, gravity separation, and magnetic separation can yield valuable mineral concentrates with recoveries in the range of 80 to 95% of the value in the ore. However, there are important ore types in which the nature of mineralization is not amenable to physical concentration, and so primary processing by chemical means is necessary. 

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