Professionally develop all kinds of ultra-fine crushing equipment, ultra-fine powder processing, conveying, filling technology.
Date: 2013-04-04 ┆ Source: China Feed Machinery Network ┆Back
1. Overview <br> The development and use of ultra-fine crusher and ultra-classified machine are inseparable from the development of non-metallic mineral industry, especially recently, the development of China's non-metallic mineral industry and the development of the crusher industry have made Fine pulverization and ultra-segmentation technology have been further improved. Therefore, taking the development of non-metallic mineral industry as the background, this article analyzes the current status of China's ultra-fine crusher and ultra-classified machine and the market space for its development.
2. Current status of China's non-metallic mineral industry and its preparation.
At present, China's non-metallic mineral industry has a considerable scale, and both output and export volume have shown an increasing trend. However, the quality and grade of domestic products are not high enough to meet the development requirements of modern high-tech and new materials industries. Many non-metallic mineral deep-processing products also rely on imports. For example, domestic high- and medium-grade glass raw materials and electronic-grade spherical silicon powders are completely dependent on imports . Many non-metallic minerals are white minerals. The first basic requirement for deep processing operations is to improve their whiteness, followed by the protection of graphite scales and mineral fibers with fiber minerals. Knowing the characteristics of minerals and the requirements for their deep processing, we can skillfully combine the process flow to achieve the goals of energy saving, environmental protection, simplicity, and better concentrate grade and better recovery. The purpose of ultra-fine processing of non-metallic minerals is mainly to develop the special properties of non-metallic minerals in the ultra-fine (fine) powder state.
2.1 Fully develop the various effects of small particles. The basic purpose of studying ultrafine powders is to develop various effects of small particles. Because ultrafine (fine) powders will bring quantum size effects, small size effects, surface effects and macroscopic quantum tunneling effects, this is important for the development of non-metallic natural nanomaterials (such as graphite, zeolite, kaolin, diatomite, perlite). Etc.) and the use of synthetic non-metallic mineral nanomaterials (such as calcium carbonate, titanium dioxide, silicon dioxide, carbon black, etc.) are very important.
2.2 High purification first, and then ultra-fine high purification are to prevent the interference of foreign impurities, and then fully reflect the characteristics of the substance itself. Many products ca n’t reflect its value without high purification. For example, ultrafine powder with W (SiO2) of 99.99% is currently limited to laboratory results in China, and there is no industrial practice. The price of imported high-end products can reach 150,000 tons, W (ZrO) 99.999% ultra-fine powder is more than 300 times the price of ordinary refractory ZrO powder. With purity, it is possible to talk about ultra-fineness, otherwise there is fineness but the purity is not sufficient, which is a waste of human, material and financial resources. Twenty years ago, the research object of ultra-fine powders was powders with a particle size of 3 m or more, and ten years ago they were materials with a particle size of 1 m or more. In recent years, research into nano-scale materials has been progressed. As the particle size becomes smaller, more properties of the material itself will be developed.
2.3 Functionalization and Compounding The possible functionalization and compounding is the result of people's pursuit of material properties, and it is also the demand of high-tech development for materials. People have researched and used the unique functions of ultrafine powder in some aspects, and artificially endowed it with new functions to make it better serve people.
2.4 Relationship between refinement and special requirements The refinement of powder materials involves its particle size, particle size distribution, particle shape, specific surface area, pore volume, pore size, crystal phase, electrical conductivity, magnetic properties, light absorption, light conductivity, etc. A series of features. Powders with different characteristics have different effects in terms of application. For example, the SiO powder we usually use for packaging materials has different particle shapes (corner powder and spherical powder), and the packaging results are completely different; the product particle size distribution is different, and the results are much different.
3. Research and development of China's ultra-fine crusher and ultra-fine-diving machine <br> China has nearly 160 patents for ultra-fine crusher from 1995 to 2005. From this we can see that China's ultra-fine crusher and ultra-fine-grade crusher Machine development overview.
3.1 Ultrafine crushing theory and practice 3.1.1 Research on ultrafine crushing theory The crushing theory is the theoretical basis for solving the relationship between material crushing and energy consumption. Exploring the internal relationship between the crushing state of materials and energy consumption is more conducive to the guidance of manufacturing. More energy-efficient crushing equipment has important theoretical research value and great practical significance for reducing energy consumption and saving energy. Since the new concept of fragmentation theory was put forward in the 19th century, Gabarov studied the energy consumption of crushing from the perspective of structural chemistry in the 1980s. After more than 100 years of development and improvement, the crushing theory plays an important guiding role in the field of crushing. However, these theories have some shortcomings and limitations to a certain extent. Starting from practical use, the three major smashing theories have their own scope of application and have a certain one-sidedness. With the development of science and technology, the existing theories lag behind practice, and the shortcomings and deficiencies of traditional fragmentation theories have become increasingly prominent, and they can no longer play a guiding role in many fields. For this reason, it is imminent to seek a more reasonable, accurate, and broken theory that can reflect the actual crushing state. The process of material deformation and crushing is very complicated. It is not an isolated system, but an open system that exchanges material and energy with the outside world. It is also a spiral evolution process from steady state to gradual change and abrupt change, accompanied by energy such as sound and heat. Dissipation. In order to establish a complete system and establish a material crushing power consumption equation, multidisciplinary theory is required as the basis. On the premise of multidisciplinary cross integration, it is possible to establish a power consumption equation that is more complete and comprehensive, and to reveal the complex system of material crushing. Internal evolution mechanism. Based on the pulverization mechanism of fluidized bed jet milling, the effects of working fluid pressure and the number of nozzles on the morphology of SiC particles in the pulverization chamber were studied. Increasing the pressure of the working medium in the crushing cavity can increase the crushing strength; using two nozzles in the crushing cavity to increase the probability of particles colliding with each other is an effective method for preparing flake SiC powder. A pulverizing system using a fluidized-bed jet mill and a multi-stage turbine classifier can prepare multi-grade ultra-fine SiC platelet fine powder with good product quality. The numerical simulation of the steady three-dimensional turbulent flow field in the suction cavity of the turbulent pulverizer was performed with the three-dimensional viscous flow calculation software NUMECA. The pressure distribution and velocity distribution of the flow field inside the suction cavity were obtained, and the suction cavity was visually displayed. The internal flow phenomenon lays the foundation for the combined calculation of the subsequent stages. The composite crushing system composed of high-pressure roller mill and agitator mill was used to test the wet superfine grinding of calcium carbonate materials. The test results show that the system can effectively improve the fineness of the material and reduce energy consumption, which may be related to the particles in the high-pressure roller. The micro-cracks are generated after the mill is compressed; the number of high-pressure roll mill pre-grindings significantly affects the product size and energy saving effect of the agitator mill; the simulation of the failure behavior of various irregularly shaped particles shows that the phenomenon of micro-cracks when the grain is compressed is different Anisotropy is related to stress distribution. Various theoretical studies have shown that the ultra-fine crushing theory should have a different expression from the current three major crushing theories, but how to perform it correctly still needs to be studied by the people in the crushing community, and a complete expression formula is expected to appear soon. As a professional production tip of the crusher, you need to pay attention to: ①The thinking method of developing crushing fine material equipment is different from that of crushing coarse particles; ②The development of ultrafine crusher should be multi-force field.
3.1.2 Ultra-fine crushing machinery China's ultra-fine crushing technology started in the 1960s; after introducing, digesting, absorbing, and developing a series of operations, it began to produce domestically-made fine jaw crushers, such as finger crushers, in the 1980s. Mills, tower mills, jet mills, etc .; By the mid-1990s, China had basically formed its own production sequence of ultra-fine crushers, but because the ultra-subdivided machines must conform to the principles of fluid mechanics, the development was more difficult, so Fewer developers. The ultra-fine stirring mill started in 1928. In 1952, DuPont of the United States introduced a vertical sand mill. In the 1980s, Drais Corporation successfully developed a DCP ring gap stirring mill, which greatly improved the crushing and dispersion efficiency. In recent years, Germany and Japan are developing submicron and nanometer superfine stirring mills, such as S, C and ZR120 centrifugal superfine stirring mills.
4. Development direction of China's crushing machinery <br> <Modern engineering technology will require more and more high-purity ultra-fine powders. Ultra-fine crushing technology will play an increasingly important role in high-tech research and development. The high-tech industry is closely related to non-metallic minerals. In the future development of non-metallic mineral deep-processing technology and industrial development, the development of high-tech and its industries must be considered; modern non-metal deep-processing technology and traditional industrial processing technology penetrate into each other, and their development must be Consider the technological transformation and progress of traditional industries; in order to make better use of limited non-metallic mineral resources, comprehensive utilization must be considered.