Winners, classifiers – why is it necessary to perform ultra-fine classification of materials?

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Ultra-fine powder raw materials are not only the basis for producing structural materials; they are also materials with special functions, and are essential in many fields such as fine ceramics, electronic components, bioengineering applications, new types of copying materials, high-quality refractory materials, and materials related to the fine chemical industry. With the increasingly widespread use of ultra-fine powders in modern industry, the technology for grading ultra-fine powders has become increasingly important in powder processing. I. Purpose and Significance of Classification At present, it is difficult to achieve the desired particle size of ultra-fine powders produced by mechanical methods through crushing alone; as a result, the products usually have a wide range of particle sizes. In modern applications across various industrial fields, ultra-fine powder products are often required to have a specific particle size distribution. Furthermore, during the grinding process, only a portion of the powder meets the required particle size specifications, while the other portion does not. If these products that meet the requirements are not separated in a timely manner and are ground together with those that do not meet the requirements, it leads to energy waste and over-grinding of some of the products. To this end, the product must be sorted during the production of ultra-fine powders. On the one hand, it controls the particle size of the product to remain within the desired range; on the other hand, it ensures that the products with the desired particle size in the mixed powder are separated out promptly. II. Working principle of ultra-fine classification: The classifier, together with the dust collector and the exhaust fan, forms a classification system. Under the suction force of the fan, the material enters from the feed inlet at the lower end of the classifier and moves rapidly with the upward airflow to the classification zone. There, the strong centrifugal force generated by the rapidly rotating classification vortex separates the coarse and fine particles. The fine particles that meet the required particle size criteria pass through the gaps between the blades of the classification wheel and are collected in the cyclone separator or dust collector. The coarse particles, along with some fine particles, collide with the walls and lose their velocity; they then descend along the wall to the secondary air inlet. There, thanks to the intense washing effect of the secondary air, the coarse and fine particles are separated again – the fine particles rise back to the classification zone for further separation, while the coarse particles descend to the discharge outlet. III. Characteristics of grading equipment: 1. No water is required, and there is no need for washing; it operates in a completely dry process, enabling the production of abrasive powder with a narrower particle size distribution and without contamination ； A single grading can be processed into products of any grade in accordance with current domestic and international standards (such as: Chinese standard W63–W3.5, Japanese standard 240#–3000#, and European standard F230/53–F1200/3). The yield of odd-numbered finished products exceeds 75%. 2. It features high grading precision, more accurate cut particle size, lower required rotation speed, and a long service life. 3. Independent cast bearing housings that do not deform and have a long service life. 4. Optimized transmission design with low bearing stress and long service life. 5. A unique piping design facilitates powder flow, reduces wear, and makes it easy to replace and maintain the parts that are prone to wear. 6. The company’s proprietary variable-frequency feeding system helps with the dispersion of materials, ensuring continuous, uniform, and stable feeding, which in turn aids in controlling the particle size of the products. 7. A unique internal circulation secondary air design with adjustable grading cone gaps reduces air consumption**, thereby lowering the energy required for grading and ensuring thorough extraction of fine powder. 8. Separating the flow paths helps to reduce wear at the bottom of the grading wheel, and is more conducive to the control of larger particles. 9. Fully enclosed negative-pressure operation, with no dust pollution. 10. Good stability: once the parameters are adjusted, stable production can be achieved ； 11. In particular, the core competitive advantage of more thorough extraction of fine powders and better stability has been widely recognized by the industry. 12. The entire system is equipped with automated control, allowing for one-button start/stop; it is simple to operate, and connection to a central control system enables remote control. IV. Materials Suitable for Use in Classifiers The ZJ-F series of precision air-classifiers are capable of classifying materials that cannot be sorted using conventional sorting equipment. They are particularly suitable for processing products where strict limits on maximum particle size and a narrow particle size distribution are required, such as heavy calcium carbonate, kaolin, talcum powder, barite powder, copier toner, coatings, mica, graphite, auxins, aluminum hydroxide, and others. ◆ High-purity applications: The ZJ-F series of precision air classification machines can handle materials with extremely strict requirements regarding impurity levels or those that are highly sensitive to iron, while also meeting the requirements regarding particle size and particle size distribution. Typical materials include: phosphors, titanium dioxide, starch, silica gel, aluminum, copper, luminescent powders, and various high-purity pigments. ◆ Abrasives and hard materials: The ZJ-F series of precision air-classifiers are capable of achieving ultra-fine classification of hard materials with a Mohs hardness of 7 or higher. The use of vertical eddy current classifiers results in minimal wear on the equipment. The speed of the grading wheel can be adjusted, and the crushing parameters can be optimized for selection; by combining multiple graders, narrow-band grading of several particle size ranges can be accomplished in one go. Typical products include: diamond, silicon carbide, boron carbide, tungsten carbide, special ceramics, emery, etc. ◆ Food, health products, pharmaceuticals: The ZJ-F series of precision air-classification machines are used for the ultra-fine processing of pharmaceuticals, food, and health products. Their capabilities in low-temperature grinding, high-purity processing, achieving high levels of surface finish, as well as easy cleaning, make the ZJ-F series an ideal choice for the pharmaceutical, health product, and food industries. These features not only improve the bioavailability and efficacy of drugs but also reduce production costs. Typical products include: pollen, hawthorn, shiitake mushrooms, pearl powder, stomach medicines, nimodipine, antibiotics, contrast agents, ganoderma, gallnut, polygonum multiflorum, and others. ◆ Other industries: The ZJ-F series of precision air classification machines can be used for classification in a closed-loop system with the aid of inert gases, for sorting materials that are highly prone to combustion, oxidation, or explosion. Such as iron carbide powder, nickel powder, tungsten-cobalt alloy powder, refined selenium powder, etc