Mica beneficiation is the separation process of raw mica and gangue. Industrially, mica natural crystals are directly processed into the desired products. The larger the mica crystals and the absence of defects, the higher the crystal value. Therefore, the integrity of the natural crystals of mica should be protected as much as possible during the beneficiation process. Mica's beneficiation methods include hand selection, friction selection, shape beneficiation, etc., and flotation and air separation are used for small mica (crystal size <4mm2).
1 Hand selection is to select single raw material mica on the mining face or pit ore heap. The mica continuous body is manually crushed and then sorted. The advantage of the hand selection method is simple operation, no complicated equipment, and no working conditions. Restricted. The shortcomings of hand selection are labor intensity, poor working conditions and low production efficiency. Some raw mica are difficult to recycle due to hand-selected conditions, and even affect the recovery rate of mica.
2. Friction beneficiation The principle of friction dressing is based on the difference between the sliding friction coefficient of the flaky mica and the rolling friction coefficient of the gangue. When the inclination of the inclined surface is greater than or equal to the friction angle of the mica crystal, the circular gangue It rolls along the slope because its overturning moment is greater than the stabilizing moment. The mica crystal has a sheet-like shape. When it falls, its maximum surface is attached to the slope. The crystal area and thickness are greatly different, which hinders the generation of overturning moment and forces the mica crystal. Since different gangue and mica coefficient of friction, and therefore falling along different trajectories inclined plane sliding many friction beneficiation equipment, metal swash plate sorting machine, the coil is selected from Guang, a belt deflector swash plate sorter and The inclined plate sorting machine with "hill type" board, etc. The sorting degree of this sorting machine is 20-70mm, the production capacity is 72-225m3/d, and the mica drawing yield is 85-95%.
3. The essence of shape beneficiation method is that the mica crystal has a sheet-like structure, so it can fall into a narrow slit, and the gangue is pulled into an irregular block, so only the cuttings with a size smaller than the slit width can be combined with the mica. Falling into the narrow slit, because the mica and the gangue are different through the sieve, the separation can be achieved. The shape beneficiation is often carried out on the multi-layer sieve, the first sieve is strip-shaped, and the second sieve is square. . The mica is in the form of a sheet, which is easy to pass through the sieve joint, and the gangue is not easy to pass through the sieve joint. When the original ore enters the sieve surface, the mica sheet and the small piece of gangue enter the second sieve surface through the sieve hole due to the vibration of the sieve surface. Because the second layer of sieve surface is a square hole, it can sieve small pieces of gangue, and the mica piece remains on the sieve surface. This method has the disadvantages of simple process, low equipment investment, large production capacity and high efficiency. Therefore, it is widely used in mica mines.
4. Flotation flotation is mainly used to select crushed mica. There are currently two methods of sorting: the first method is to float mica with an amine collector in an acid medium towel. The pH value is controlled below 3.5, the upper limit of flotation particle size is 1.2mm, and the mud is needed before flotation. The concentration of pulp is 30-45, the recovery rate of concentrate is more than 77, and the concentrate grade is 98%. The other method is Flotation with an anionic collector in an alkaline medium, pH 10.5-8, upper limit of flotation size. .8mm, need to remove mud before the selection of people, the tip grade can reach more than 98%, the recovery rate is higher.
5. Wind selection In the early 1980s, foreign countries adopted wind selection and made great progress, and many successful examples appeared. For example, the “Zigzag†air-selection machine used by the US Bureau of Mines has been successfully applied to select coarse-grained mica and grain tips. The process of wind selection is to first break the ore to a certain degree of pull. The general crushing size is 0.25. -18mm. Then sieve, the narrower the grain size, the better the wind selection effect. Because of the uniform particle size, the mica plate is much lighter and easier to separate than the same size gangue particles.
Metal 3D Printer,Ceramic Sand Casting Molds,Advanced Metal 3D Printer,Compact Binder Jet 3D Printer
Guangdong Fenghua Zhuoli Technology Co., Ltd , https://www.fhzl3d-printer.com