Mica is a common silicate mineral with a layered structure and monoclinic crystal system. There are many types of mica minerals, including biotite, muscovite, phlogopite, lepidolite, sericite, etc., which are widely used in industry. Mica is also one of the main rock-forming minerals, and often appears as an associated mineral in various ore deposits. Therefore, the research on mica extraction process is of great significance in the comprehensive utilization of minerals.
This article will introduce 6 mica extraction processes used in actual production.
Use the table of contents below to navigate through the guide:
Mica manual extraction process is a method of separation larger flake mica in small scale plant. It is to manually select the mica that has been dissociated from the monomer on the mining face or the ore pile at the pit, or use the hand hammer to break the conjoined body to select the mica. Although mica manual extraction process is simple and uses less equipment, it is labor-intensive.
Mica shape extraction process uses the different shapes of lamellar mica crystals and gangue minerals for separation. It needs to use cylinder screen and vibrating screen, which are generally screens with more than two layers of different sieve holes. When the raw ore enters the screen surface, the flake mica stays on the screen surface under vibration or rolling action, and small pieces of flake mica and gangue minerals enter the second screen surface, and then gangue falls under the screen to realize the separation of mica and gangue. Mica shape extraction process is a common separation method in mica extraction plants because of its simple process, less equipment and high production efficiency.
Mica friction extraction process is also one of the methods for separating flaky mica. It uses the different friction coefficients of mica crystals and gangue blocks for separation. The equipment used includes metal plate separator, spiral separator, inclined plate separator and so on. Although mica friction extraction process has high production efficiency, when the ore thickness is large, gangue and mica with similar shapes are easily mixed, and the equipment and process are still imperfect, so it has not been widely used.
Mica flotation process can be applied to flake mica and crushed mica, and can be divided into acidic cation flotation method and alkaline anion-cation flotation method. The acid cation flotation method can effectively recover coarse mica above 14 mesh. Before separation, desliming is carried out on screens of 150 to 200 mesh and quartz is suppressed using sulfuric acid as a pH regulator. When pH is about 0.4, the flotation effect is better, and long carbon chain organic collector such as acetate is used as cationic collector for recovery.
Alkaline anion-cation flotation method can float mica minerals above 20 mesh, allowing a small amount of sludge in the pulp. Sodium carbonate and calcium lignosulfonate are used as pulp inhibitors, wherein calcium carbonate also acts as a pH adjuster, and calcium lignosulfonate also acts as a pulp dispersant. When the pH is between 8.0 and 10.5, the recovery effect of mica is better. The anionic collector is a combination of fatty acid and fatty acid. When there is sludge in the pulp, it is necessary to add ammonium acetate as a cationic collector to increase its selectivity.
Mica wind extraction method is suitable for crushed mica minerals, and the general process is crushing-classification-wind separation. When the ore is crushed, the mica forms into flakes. Quartz and feldspar-like gangue minerals are massive particles. Multi-level classification can be used to classify the selected materials into narrower particle sizes, and they can be separated according to the difference of their suspension speed in the airflow. The separation efficiency of mica wind extraction method is not high, and it generally needs to be used in conjunction with multi-stage separation or other methods.
Mica gravity separation is a common method for separation of mica and gangue minerals. It mainly utilizes the density difference between mica and gangue for separation. Commonly used equipment includes shaking table, spiral chute, etc. Mica gravity separation process can be used in combination with other methods to improve the processing effect.
The above are 6 mica extraction processes. It should be noted that the properties of mica minerals in different deposits are quite different. It is necessary to scientifically and rationally formulate the process flow through beneficiation experiments to avoid economic losses and resource waste caused by blind selection.