What are the methods for beneficiating chalcopyrite and pyrite?

Chalcopyrite (CuFeS₂) and pyrite (FeS₂) are common sulfide minerals that often coexist in ores. Among them, chalcopyrite is one of the main minerals for obtaining copper, and pyrite coexists with it, which will affect the quality of copper concentrate. In the beneficiation process of copper ore, effective separation of chalcopyrite and pyrite is crucial to improving the grade and recovery rate of copper concentrate. However, there are many similarities between the two in crystal structure, chemical composition, physical properties, etc., and separation is somewhat difficult. At present, the common chalcopyrite copper ore beneficiation and separation methods are mainly flotation, magnetic separation and gravity separation.

1. Chalcopyrite and pyrite flotation separation method

Flotation separation is based on the difference in the physical and chemical properties of the mineral surface, especially the wettability of the mineral surface to achieve mineral separation. There are certain differences in the surface properties of chalcopyrite and pyrite. During the flotation process, different flotation agents are added to change their surface wettability, so that chalcopyrite selectively attaches to the bubbles and floats, while pyrite remains in the pulp or is suppressed.

Flotation separation of brass and pyrite has high sorting accuracy and can achieve effective separation of chalcopyrite and pyrite to a certain extent, and obtain higher-grade copper concentrate. It is mostly suitable for the recovery of fine-grained minerals, especially for the treatment of complex polymetallic sulfide ores, in which chalcopyrite and pyrite are closely coexisting and the copper content has a certain economic recovery value. According to the properties of the ore and the requirements of mineral processing, the reagent system and operating conditions can be flexibly adjusted.

2. Chalcopyrite and pyrite magnetic separation method

Magnetic separation is to use the magnetic difference of minerals for mineral processing. Although chalcopyrite and pyrite are weakly magnetic minerals, their magnetic performance is different under certain conditions. The magnetism of pyrite is stronger than that of chalcopyrite. During the magnetic separation process, the ore is sent into the magnetic field of the magnetic separator. By adjusting the parameters such as the magnetic field strength and the magnetic field gradient, the pyrite and other mineral particles with relatively strong magnetism are adsorbed on the magnetic poles by the magnetic field, while the non-magnetic or weakly magnetic chalcopyrite is not affected by the magnetic field, thus achieving separation.

The equipment required for magnetic separation is relatively simple and the operating cost is low. The equipment is relatively simple, the operating cost is low, and the operation and maintenance of the magnetic separation equipment are relatively easy. It has little impact on the surrounding environment. For some chalcopyrite and pyrite ores that contain magnetic impurities or have changed magnetism after special treatment (such as roasting, etc.), the magnetic separation method can effectively remove magnetic minerals.

It is suitable for processing ores in which chalcopyrite and pyrite coexist and the magnetism of pyrite is relatively prominent, such as some ores in which the magnetism of pyrite is enhanced after hydrothermal alteration or oxidation. Magnetic separation also has certain application value in some small ore dressing plants or as a pretreatment link in the combined ore dressing process.

3. Chalcopyrite and pyrite gravity separation method

Gravity separation method is based on the difference in mineral density. Under the action of external forces such as gravity field or centrifugal field, mineral particles of different densities are layered or graded according to density or particle size, thereby achieving mineral separation. The density of chalcopyrite is about 4.1-4.3g/cm³, and the density of pyrite is about 4.9-5.2g/cm³. There is a certain density difference between the two. In the gravity separation process, the mineral particles in the slurry are moved by the action of water flow or mechanical force. The denser pyrite particles tend to be enriched at the bottom of the equipment or in a specific area, while the less dense chalcopyrite is distributed in other areas.

The gravity separation process is relatively simple, does not require a complex reagent system, is low-cost and environmentally friendly. For coarse-grained chalcopyrite and pyrite, gravity separation can quickly and effectively remove a large amount of gangue minerals and improve the grade of the selected ore. In some small mines or as a pre-selection operation for large-scale beneficiation plants, gravity separation can play an important role, providing high-grade selected raw materials for subsequent flotation or other beneficiation methods.

The above briefly introduces the process method for effective separation of brass and pyrite. In actual beneficiation plants, the properties of copper ore are complex. In addition to associated pyrite, there are other gangue minerals. If you want to effectively remove impurities and improve the grade of copper concentrate, you need to customize a suitable process plan according to the properties of the ore. Therefore, it is recommended to conduct beneficiation tests and design a reasonable process based on test analysis. Xinhai has nearly 30 years of experience in copper beneficiation and has completed many copper beneficiation projects. If you have any needs, please contact Xinhai hotline: 15311826613!