Flotation method is a widely used beneficiation method in concentrators. Different ore properties determine different flotation processes. According to the number of flotation process sections (the number of grinding and flotation), the common flotation process can be divided into one-stage grinding and flotation process and stage grinding and flotation process. So, what is the direct difference between the two flotation processes? How should we choose in actual production? Fodamon engineer explains the following for you.
Primary grinding and flotation process
If the ore has been grinded to the upper limit of flotation particle size after one grinding, and any flotation product does not need to be grinded again, it is called a one-stage grinding flotation process.
The one-stage grinding and flotation process is applicable to ores with uniform distribution of useful minerals, relatively coarse particle size and not easy to muddle. In addition, if the fine-grained uniformly disseminated ore is grinded twice continuously and the flotation products do not need to be grinded again, such a flotation process is still a one-stage flotation process, or a two grinding and one separation process.
Stage grinding and flotation process
Due to the uneven distribution of ore, if a flotation product needs to be reground and re selected, it is called two-stage grinding and flotation process. By analogy, there are multi-stage grinding and flotation processes (more than two-stage grinding and flotation processes are collectively referred to as stage grinding and flotation processes). The common stage grinding and flotation process is mainly two-stage grinding and flotation process, including concentrate regrinding process, middling regrinding process and tailings regrinding process.
Stage grinding and flotation process is mostly used to deal with ores with complex particle size embedded in useful minerals, or ores prone to argillization in the grinding process.
How to choose?
In the actual production process, the number of segments is often determined according to the embedded particle size of minerals. Therefore, we can choose according to the embedding characteristics of useful minerals.
- Coarse ore particles are evenly embedded
The crystalline particle size of useful minerals is relatively coarse and uniform. When the ore is ground to the upper limit of particle size that can be floated (such as 0.3mm for heavy metal sulfide ore), the useful minerals can basically realize monomer separation. At this time, qualified concentrate and waste tailings can be obtained by one-stage grinding and flotation process (flotation after rough grinding).
- Fine ore particles are evenly disseminated
The crystal size of useful minerals is fine and uniform, and it usually needs to be ground below -0.074mm to make the useful minerals basically achieve monomer separation. For this type of ore, when the impregnation particle size is fine and uniform, a one-stage grinding and flotation process of two grinding and one selection can be adopted. When the impregnation particle size is fine and uneven, and the particle size range for monomer separation is wide, the two-stage grinding and flotation process of regrinding and reselection of the middlings in the first stage of flotation can also be adopted.
- Uneven ore leaching
The useful minerals are coarse, medium and fine particles with uneven leaching, which is more common in practice. For this kind of ore, the two-stage grinding and flotation process of regrinding and reselection of middling or tailings is mostly adopted, that is, the coarse-grained monomers are separated under rough grinding to select some qualified concentrate, and then the middling or rich tailings in continuous body are regrinding and reselection.
- Ore aggregate leaching
In some polymetallic sulfide ores, several useful minerals disseminated by fine particles often exist in the form of coarse aggregates. The two-stage grinding and flotation process of regrinding and re concentration of the first stage flotation concentrate can be used to treat this type of ore. In the first stage, the useful mineral aggregate is grinded to separate from gangue, and the mixed concentrate is selected, and then the mixed concentrate is grinded and re selected to separate various useful minerals from each other.
- Complex ore imbedding and dyeing
If the ore has the characteristics of both uneven leaching and aggregate leaching, the two-stage grinding and flotation process of regrinding rich tailings in the first stage flotation and regrinding and re concentration of mixed concentrate in the first and second stages flotation can be adopted.
Reasonable selection of flotation process is the main factor to obtain good separation index and reduce production cost. When choosing the flotation process, the mine owner needs to conduct ore beneficiation test to determine the ore composition and ore properties, and select a reasonable flotation process that meets his own mine conditions according to the test results.