Magnesite is an important raw material for refining magnesium. Magnesite is often associated with talc. For magnesite containing a large amount of talc, comprehensive recovery can be adopted. Next, we will introduce the flotation process of magnesite and the comprehensive recovery method of magnesite and talc.
After years of flotation research and production practice, the following characteristics of magnesite flotation in China are summarized:
1. Magnesite and gangue minerals are embedded with coarse grain size and easy to dissociate monomer, which is suitable for rough grinding.
2. A better separation effect can be obtained by reverse flotation of silicon with amine collectors and positive flotation of magnesite with fatty acid collectors.
3. Magnesite ore containing a large amount of talc can be comprehensively recycled.
4. The positive flotation of magnesite should be carried out in alkaline pulp. Under certain pH conditions, adding sodium silicate and sodium hexametaphosphate can selectively partially inhibit calcium containing minerals such as dolomite.
Talc is a non-polar mineral with low surface wettability and good natural floatability. It is easy to separate from magnesite. Film talc can float only by adding foaming agent. Other talc can also float in neutral medium after adding amine collectors.
However, magnesite and dolomite are polar minerals. After crushing, the surface of the minerals presents ionic bond, which is strong in hydrophilicity and is not easy to float. Moreover, the difference in floatability between them is very small. In addition, calcium, iron and magnesium are easy to form isomorphism, so it is difficult to separate them.
At present, the flotation of magnesite generally adopts reverse flotation to remove silicate minerals such as talc, add effective inhibitors to suppress other gangue minerals, and use fatty acid collectors to float magnesite in alkaline pulp in reverse positive flotation.
