Quartz sand dry magnetic separator

Overview
.>Dry magnetic separator is widely used for sorting weakly magnetic minerals smaller than millimeters and re-concentration of rare metal ores. It has three types: single disc (diameter=mm), double disc (=mm) and triple disc (=mm). The magnetic field intensity can reach kiloamps/meter.
.>Disc dry type strong magnetic separator The main part of the magnetic separator is composed of a gable-shaped electromagnet and a rotatable suspended induction disc. The disc is like a flip-up dish with sharp teeth. Its diameter is about one-half larger than the width of the ore belt. The disc adopts worm gear reduction transmission and the pole distance between the disc and the electromagnet can be adjusted through the handwheel (adjustment range). ) mm.
.>In order to prevent clogging, a weak magnetic field pole is installed in the feeding cylinder to discharge the strong magnetic minerals in the feed in advance. Its working principle and sorting process: The ore is discharged from the ore feeding cylinder with strong magnetic minerals in advance and then evenly discharged onto the ore feeding belt, and is sent by the belt to the magnetic field gap under the disc. The weakly magnetic minerals are attracted by the magnetic force. on the tines of the disc and brought to both sides of the belt as the disc rotates. Here, due to the sharp drop in magnetic field strength, the magnetic products on both sides of the belt (generally concentrates) fall behind under the action of gravity and centrifugal force. Non-magnetic The product is transported by a belt to the tailings end and discharged into a trough for non-magnetic products (usually tailings).
.>The operating factors of the disc magnetic separator mainly include: ore feeding thickness, magnetic field strength, working gap and ore feeding speed, etc. There are many types of strong magnetic field magnetic separators. Magnetic separators are classified according to the medium in the selection process according to operating conditions. In addition to dry magnetic separators, there are also wet magnetic separators.
.>Introduction
.>Dry magnetic separator is a magnetic mineral separation machine for sorting dry magnetic minerals. Compared with wet magnetic separator, liquid is used as diluent to improve the separation. In terms of efficiency, dry magnetic separators require that the dried mineral particles to be sorted can move freely between themselves and form an independent free state, otherwise it will affect the magnetic separation effect and even cause inseparability. The dry magnetic separator is suitable for the wet magnetic separation of magnetite, pyrrhotite, roasted ore, ilmenite and other materials below the particle size. It is also used for iron removal of coal, non-metallic ores, building materials and other materials.
.>The magnetic system of the dry magnetic separator is made of high-quality ferrite material or compounded with rare earth magnet steel. The average magnetic induction intensity on the cylinder surface is ~. According to the user's needs, various magnetic separations with different surface strengths, such as downstream, semi-countercurrent, and countercurrent, can be provided. This magnetic separator has the advantages of simple structure, large processing capacity, convenient operation and easy maintenance.
.>Application scope of dry magnetic separator:
.>This series of dry magnetic separator is suitable for refractory materials, chemical materials, grain and oil machinery, abrasives, ceramics, metallurgy, cement, powder metallurgy, It is used to remove (select) iron from rubber, ore and other materials and can be used in conjunction with Raymond mill, pulverizer and ball mill.
.>Features
.>Suitable for wet magnetic separation of magnetite, pyrrhotite, roasted ore, ilmenite and other materials below particle size. It is also used for coal, non-metallic ores, building materials, etc. Iron removal operations from materials. The magnetic system of the dry magnetic separator is made of high-quality ferrite material or compounded with rare earth magnet steel. The average magnetic induction intensity on the cylinder surface is ~. It has simple structure, large processing capacity, convenient operation and easy maintenance.
.>Working Principle
.>After the slurry flows into the tank body through the ore feeding box, the ore particles enter the feeding area of the tank body in a loose state under the action of the water flow from the ore feeding water spray pipe. Under the action of the magnetic field, the magnetic mineral particles undergo magnetic aggregation to form magnetic clusters or magnetic links. The magnetic clusters or magnetic links move towards the magnetic poles under the action of magnetic force in the slurry and are adsorbed on the cylinder. Since the polarity of the magnetic poles are alternately arranged along the rotation direction of the cylinder and are fixed during operation, the magnetic clusters or magnetic links are mixed in the magnetic clusters or magnetic links, causing a magnetic stirring phenomenon due to the alternating magnetic poles when the cylinder rotates. Non-magnetic minerals such as gangue fall off during the turning, and the magnetic clusters or magnetic lotus that are finally attracted to the surface of the cylinder are the concentrate. The concentrate is transferred to the edge of the magnetic system along with the cylinder, where the weakest magnetic force is discharged into the concentrate tank under the action of the flushing water jet from the unloading water pipe. If it is a full-magnetic magnetic roller unloading, a brush roller is used. Non-magnetic or weakly magnetic minerals are left in the slurry and are discharged out of the tank as tailings.
.>Factors affecting magnetic separation indicators
.>The factors affecting the indicators of dry magnetic separator[] mainly include ore properties (grade, magnetism, particle size and moisture, etc.), equipment performance and operating level, etc. Under certain conditions of working performance, the operation adjustment should be determined according to the properties of the ore being processed and the requirements for product indicators. The main operating adjustment factors include roller speed, baffle position and ore feeding amount. Reasonable adjustment of these three factors can improve the magnetic separation indicators.
.>The adjustment of the roller speed determines 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 roller speed and centrifugal force increases the magnetic turning effect and also enhances the quality of the concentrate and the amount of ore processed. However, as the speed increases, the amount of tailings thrown out also increases, and the grade of the tailings increases accordingly. On the contrary, lowering the speed has the opposite effect, and both the concentrate grade and the tailings grade will decrease.
.>The adjustment of the baffle mainly refers to adjusting the position of the upper and lower tailings baffles to control the grade of the tailings (or the amount of tailings). The closer the baffle is to the barrel skin, the greater the amount of tailings and the higher the quality of the tailings. At the same time, the amount of medium ore will be reduced accordingly, and the grade of medium ore will be increased. The farther the baffle is from the surface of the cylinder, the effect is exactly the opposite. Of course, changes in the amount and grade of medium ore will inevitably affect the grade of concentrate. For example, when the amount of ore in the upper roller is small and the grade is high, the concentrate grade of the lower roller is also easy to increase. This is especially obvious when processing coarse-grained ore.
.>Adjustment of the ore feeding amount. Its size determines the thickness of the material layer on the roller. When the ore feeding amount is large, the material layer is thick. The magnetic ore particles on the surface of the material layer are subject to a small magnetic force and are easily thrown into the tailings. to increase tailings grade. When processing fine-grained grades, the grade of the concentrate will also be reduced. At this time, the ore feed amount should be reduced to ensure the required separation index.
.>The selection particle size also has a great impact on the selection index of the dry double-cylinder permanent magnet magnetic separator. The index for sorting coarse particles is better than the index for sorting fine particles. This is mainly because when processing coarse-grained materials, since the material particles contain less moisture and mud, they are easy to spread on the cylinder, which is beneficial to the separation of magnetic mineral particles and non-magnetic mineral particles and is also beneficial to improving the processing capacity. Moreover, fluctuations in ore feed volume have little impact on the separation effect. The coarse weight of the mineral particles is large and the centrifugal force on the roller is also large, so the roller speed must be strictly controlled. And pay attention to adjusting the position of the baffle in time as the rotation speed changes. When the rotation speed is high, the baffle should be farther away from the drum skin, and when the rotation speed is low, it can be closer. When dealing with fine-grained grades, due to the fine particle size of the material and the high water and mud content, it is easy to form agglomerates and it is difficult to disperse the agglomerated mineral particles on the surface of the barrel. The agglomerated mineral particles are thrown into the tailings under the action of centrifugal force to make the grade of the tailings deviate. high. The finer mineral particles form magnetic links under the action of the magnetic field, and the bonding between water and slime makes it difficult for the magnetic links to disperse and discharge the slime during the magnetic turning process. Such magnetic links entering the concentrate will reduce the grade of the concentrate. In addition, the fine ore particles are smaller in weight and receive less centrifugal force than the coarser particles. Therefore, the tailings throwing belt is also narrower and is not easy for the baffle to intercept the ore. In order to reduce this impact, the ore can be classified according to particle size in advance, and each level of coarse and fine particles can be processed separately according to different conditions. When dealing with fine-grained grades, the amount of ore feed should not be too large and the roller speed should be appropriately increased. This can reduce the thickness of the material layer, strengthen the centrifugal force and magnetic flipping, destroy the magnetic agglomeration, and throw the gangue into the tailings. Since the fine-grained tailings throwing belt is narrow and the grade of the tailings belt does not change significantly from the distance from the barrel skin, the baffle can be closer to the barrel skin so that the tailings grade does not increase much, which is good for improving the concentrate grade. of.
.>Production practice has proved that the selected particle size has a great impact on the dry magnetic separation index. In order to reduce this impact, it should be determined according to the specific situation in actual operations. Beijing Iron Mine divides the ore with a selected particle size of % - The coarse grade with mesh content of %-% and the fine grade with mesh content of %-% are respectively selected to obtain better selection indicators.
.>Ore moisture has a certain impact on the effect of dry magnetic separation, especially the separation of fine particles. Because moisture will increase the cohesiveness of the magnetic clusters, the magnetic clusters will be more firmly bonded and will easily stick to the barrel skin. Even if the centrifugal force is increased, the indicators cannot be improved and sometimes worsen. Therefore, when the ore moisture is high in the rainy season, the proportion of lump ore can be appropriately increased to relatively reduce the moisture content and mud content of the ore. When the moisture content is large and affects the sorting index, the operation method is to reduce the amount of ore and ensure that qualified concentrate products are obtained. Make adjustments. When the moisture content of coarse-grained ores is less than .%, it has no significant impact on the sorting index. When the moisture content of fine-grained ores is less than .
.>The magnetic rate of the ore also affects the magnetic separation index. When the magnetic rate is high, the operation should be based on ensuring the quality of the concentrate to reduce the tailings grade as much as possible and improve the recovery rate of the ore dressing. When the magnetic rate is low, the operation should focus on ensuring the concentrate grade and also pay attention to reducing the tailings grade.
.>Precautions for use
.>The daily maintenance of the dry magnetic separator is also very important. The daily maintenance of the permanent magnet dry magnetic separator is very important due to its own working requirements and intensity. of. In particular, the replacement and maintenance of lubricating oil is particularly important.
.>The maintenance of permanent magnet dry magnetic separator is a regular task. The quality of maintenance work directly affects the operation rate and service life of the permanent magnet dry magnetic separator. In order to promptly discover defects and eliminate hidden dangers to ensure the normal operation of the machine, in addition to daily maintenance, regular shutdowns for maintenance (recommended once a month) are required to carefully inspect important components such as cylinder walls, boxes, transmission belts, etc. and make detailed records. According to the severity of defects, appropriate treatment and arrangement of mid-term repair and overhaul plans will be made.