The separation and purification technology of complex associated manganese ores has always been a thorny problem. At present, the commonly used separation technologies are nothing more than flotation, gravity separation, magnetic separation, etc. Xinhai has undertaken multiple manganese ore beneficiation projects, gained experience in multiple projects, and summarized 8 commonly used separation technologies to share with everyone.
Flotation is a relatively common separation technology in manganese ore beneficiation. Its principle is to change the properties of the mineral surface by adding specific collectors and frothers to the slurry, thereby achieving the separation of manganese from other gangue minerals. It is particularly suitable for manganese ores with complex associated minerals and fine embedded particles. Therefore, flotation can accurately capture manganese ores and is an expert in separating gangue minerals.
In complex associated manganese ores, feldspar, quartz and other minerals are often associated. The density difference between such minerals and manganese ore is extremely obvious. Manganese ore is heavier, while feldspar and quartz are lighter. For such minerals, we can use gravity separation to separate the gangue minerals by using their density differences. It is also possible to pre-treat before flotation, first remove a large amount of gangue, and then flotation, thereby reducing the flotation load.
In complex associated manganese ores, there are also some magnetic gangues, such as limonite and magnetite. Since manganese ore itself is not magnetic, we can use the magnetic difference between them to achieve separation, which is the strong magnetic separation method. In this process, we usually use strong magnetic separators or other magnetic separation equipment to quickly separate impurities and improve the purity of manganese ore.
In addition to density and magnetism, some gangue minerals are conductive, such as sulfide ores. For these impurities, we can use electrostatic separation to achieve separation. Through electrostatic separation equipment, mineral particles with different conductivity are subjected to different forces in the electric field, and finally achieve effective separation.
The leaching method uses chemical reagents to react with minerals to selectively dissolve impurity minerals and achieve manganese mineral enrichment. For manganese ores containing harmful impurities such as phosphorus and sulfur, the leaching method can effectively reduce the impurity content. For example, in a high-phosphorus manganese ore, the phosphorus content was reduced from 0.8% to 0.2% by acid leaching, and the quality of manganese ore was greatly improved, expanding its application field.
Faced with complex associated manganese ores, a single beneficiation method is often unable to cope with it, and a comprehensive beneficiation process came into being. First, use the gravity separation method for rough selection to remove most of the gangue; then use the flotation method for fine selection to separate manganese minerals from other associated minerals; supplemented by strong magnetic separation or electrostatic separation, specific impurities are removed in a targeted manner. This multi-method collaborative process can flexibly adapt to the characteristics of different manganese ores and maximize the recovery of manganese minerals. A large manganese ore enterprise uses this process, with a manganese ore recovery rate of up to 85%, a stable concentrate grade of 48%, and significant economic benefits.
For some impurities that cannot be removed by ordinary magnetic separation, such as pyrolusite and spessartine, they are weakly magnetic minerals. For this type of minerals, we recommend the use of high-gradient strong magnetic separation, using a high-gradient magnetic separator to allow manganese minerals to be separated from the associated gangue minerals in a high-gradient magnetic field under the action of the magnetic field force, thereby achieving the enrichment and purification of manganese ore.
Although we have introduced a variety of separation technologies and methods for manganese ore and gangue above, the core method is still flotation. Many methods actually add a pre-selection step before flotation to reduce the load of flotation. Flotation reagents are the key to flotation. Therefore, optimizing the type and dosage of reagents, and accurately matching collectors, frothers and regulators are the key to improving the efficiency of manganese ore dressing and purification.
In actual production, complex associated manganese ore should be subjected to mineral processing tests first to understand its composition and mineral properties, and then adopt targeted separation technology to separate impurities. As a veteran in the mineral processing industry for more than 30 years, Xinhai Mining can provide customers with a full range of EPCM+O services (i.e. mining industry chain services) from mineral processing tests, equipment installation, production training, and post-operation. If you have mineral processing needs, please contact us.
