Dry magnetic separator manufacturerThe main factors that affect the indicators of dry magnetic separators are ore properties (grade, magnetism, particle size, moisture, etc.), equipment performance, and operating level. Under certain working performance conditions, operational adjustments should be determined based on the properties of the ore being processed and the requirements for product indicators. The main operational adjustment factors include roller speed, baffle position, and the size of the ore feed. Reasonably adjusting these three factors can improve the magnetic separation index.

The adjustment of the roller speed determines the magnitude of the centrifugal force experienced by the mineral particles on the surface of the cylinder and the strength of the magnetic flipping effect of the magnetic mineral particles. Increasing the rotational speed of the roller increases the centrifugal force and enhances the magnetic flipping effect, which is beneficial for improving the concentrate grade and processing capacity. But as the speed increases, a large amount of tailings are thrown out, and the tailings taste is correspondingly improved; On the contrary, reducing the rotational speed has the opposite effect, and both the concentrate grade and tailings grade will decrease.

The adjustment of the baffle mainly refers to the upper and lower tailings baffles. Adjusting the position of the baffle can control the grade (or amount) of tailings. The closer the baffle is to the casing, the more tailings there will be, and the higher the tailings grade will be. At the same time, the amount of intermediate ore also decreases correspondingly, and the grade of intermediate ore also increases; The farther the baffle is from the surface of the cylinder, the opposite effect occurs. Of course, changes in the amount and grade of intermediate ore will inevitably affect the grade of concentrate. When the amount of ore in the upper roller is small and the grade is high, the grade of concentrate in the lower roller is also easy to increase. This is particularly evident when dealing with coarse-grained ore.

The adjustment of the feeding amount determines the thickness of the material layer on the roller. When the feeding amount is large, the material layer is thick, and the magnetic force on the surface of the material layer is small, making it easy to throw into the tailings and increase the tailings grade. When dealing with fine-grained grades, it can also reduce the grade of the concentrate. At this time, the amount of ore should be reduced to ensure the required separation indicators are obtained.

The selected particle size also has a significant impact on the selection indicators of the dry double tube permanent magnet magnetic separator. The indicators for sorting coarse particles are better than those for sorting fine particles. This is mainly because when dealing with coarse-grained materials, due to their coarse size, low moisture and mud content, they are prone to scattering on the cylinder, which is beneficial for the separation of magnetic and non-magnetic particles and also for improving processing capacity. And the fluctuation of ore supply has little effect on the sorting efficiency. The mineral particles are coarse and heavy, and the centrifugal force on the roller is also high, so the roller speed must be strictly controlled. And pay attention to adjusting the position of the baffle in a timely manner as the speed changes. When the speed is high, the baffle should be farther away from the cylinder skin, and when the speed is low, it can be closer. When dealing with fine-grained materials, due to their fine particle size, high water and mud content, they are prone to agglomeration and difficult to disperse on the surface of the drum. The agglomerated mineral particles are thrown into the tailings under centrifugal force, resulting in a higher tailings grade. The mineral particles are relatively fine, and under the action of a magnetic field, a magnetic flux is formed. In addition, the bonding between water and mineral mud makes it difficult for the magnetic flux to disperse and discharge the mineral mud during the magnetic flipping process. Such magnetic flux entering the concentrate will lower the grade of the concentrate. In addition, fine ore particles have a smaller weight and receive less centrifugal force than coarse particles, so the tailings throwing belt is also narrower, making it difficult for baffles to intercept the ore. To reduce this impact, the ore can be pre graded according to particle size, and the coarse and fine grades can be processed separately under different conditions. When dealing with fine-grained materials, the feeding amount should not be too large, and the roller speed should be appropriately increased to reduce the thickness of the material layer, strengthen centrifugal force and magnetic flipping effect, destroy magnetic agglomeration, and throw the gangue into the tailings. Due to the narrow tailings throwing belt at the fine-grained level and the insignificant change in the distance between the tailings belt and the casing, the baffle can be placed closer to the casing, so that the tailings grade does not increase significantly, which is beneficial for improving the concentrate grade.

Production practice has proven that the selected particle size has a significant impact on the dry magnetic separation indicators. In order to reduce this impact, the actual operation should be determined according to the specific situation. Beijing Iron Mine divides the ore with a selected particle size of 200 mesh, which accounts for 25%, into a coarse grade of -200 mesh with a content of 5% -8% and a fine grade of -200 mesh with a content of 50% -60%. These two grades are selected separately to obtain better separation indicators.

The moisture content of ore has a certain impact on the effectiveness of dry magnetic separation, especially on the separation of fine particles. Because moisture can increase the adhesion of the "magnetic clusters", making them more firmly bonded, and they are prone to sticking to the cylinder skin. Although increasing centrifugal force cannot improve the indicators, sometimes it can even worsen. Therefore, when the moisture content of the ore is high during the rainy season, the proportion of block ore can be appropriately increased to relatively reduce the moisture and mud content of the ore. When the moisture content is high and affects the sorting indicators, the operation can be adjusted by reducing the ore feeding amount and ensuring the production of qualified concentrate products. When processing coarse-grained ores with a moisture content of less than 2%, there is no significant impact on the selection criteria; When processing fine-grained ores with a moisture content of less than 2.5%, there is no significant impact on the selection criteria.

The magnetic permeability of the ore also has an impact on the magnetic separation index. When the magnetic permeability is high, in operation, the tailings grade should be reduced as much as possible while ensuring the quality of the concentrate, and the recovery rate of mineral processing should be improved. When the magnetic permeability is low, the operation should focus on ensuring the grade of the concentrate, while also paying attention to reducing the grade of the tailings.