10 influence factors of ultrafine quartz powder prepared by ball grinding legal system

Ultrafine quartz powder is a high-quality neutral inorganic filler, due to strong acid resistance, stable physical and chemical properties, good light transmission, high dielectic, high moisture resistance, radiation resistance, excellent high temperature resistance and high purity low ion content, low expansion, low stress and other properties, widely used in plastics, rubber, paints, coatings, ceramics, inks and catalytic and gas filtration materials and other fields. And ultrafine quartz powder is still a functional material, and the new functional material composite shows a broad application prospects, so the development of ultrafine quartz powder has practical significance.
preparation of ultra-fine quartz powder needs to use a variety of mechanical equipment, including: ball mill, vibration grinding, stirring grinding, airflow grinding, high-speed impact grinding, collome grinding and as a supporting equipment of fine grading equipment
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. Among them, high-energy ball grinding legal system to prepare ultra-fine quartz powder required less equipment, simple process, but the impact of the final product composition and performance of many factors. Among them, the nature of raw materials, ball grinding strength, ball grinding environment, ball grinding atmosphere, ball ratio, ball grinding time and ball grinding temperature are the main factors.
the structure of the ball mill
(1) the nature of raw materials. The composition of the material system and the ratio of the components are the material basis for determining the composition of the final product, and different raw material composition and group distribution ratio will get different ball grinding products even under the same ball grinding conditions.
(2) ball grinding intensity. The high-speed high-frequency impact collision of grinding medium on material in high-energy planetary grinding is beneficial to the conversion of energy and the transport and diffusion of molecules, atoms and ions. Ball grinding strength has an important influence on the formation of mechanical alloying amorphomorphoation. When the strength is low, the powder forms amorphoine for a longer time, or even can not form amorphomorphoation, when the strength is high, the formation of amorphomorphomorous time is greatly shortened, and contributes to the expansion of the amorphomorphoous composition range, when the ball grinding energy is high to a certain extent, it is more appropriate to form a stable compound than amorphomorphos. For the multi-component oxide system with high hardness and strength, because its price bond is firmer, the key energy is higher, the ball grinding strength is low, it is impossible to make it occur lattice distortion, distortion, etc., it is not mechanical chemical reaction.
(3) ball grinding environment. For inorganic non-metallic grinding, there are usually dry and wet method of grinding two methods, dry method is simple to operate, wet method can often get a smaller particle size of the grinding product. However, the time of phase change produced by wet powder grinding is much higher than that of dry method, which is due to the small coefficient of friction of wet method, the interface of particles in water can be less than the surface energy in the air, so it is difficult for powder particles to accumulate enough energy to overcome the activation potential required for phase change. When dry powder is ground to a certain extent, the occurrence of phase change is almost inevitable. Mechanically induced structural changes in materials often require particle (grain) size and free energy to reach the limit, while in wet powder grinding environments, the dissolution and "reconstruction" of the fractured surface, good lubrication and cooling environments prevent particle size and free energy from reaching the limit, thus hindering the occurrence of polycrystalline transformation.
(4) slurry concentration. In the process of wet ball grinding and crushing, the slurry concentration is also an important process parameter, which is directly related to the particle size of powder and ball grinding efficiency. Experiments show that with the increase of pulp concentration, the effect of ball grinding is getting better and better, but when the pulp concentration reaches a certain value, the effect of ball grinding time on powder particle size becomes smaller.
(5) the size of the grinding medium. High-energy ball grinding mostly use smaller carbide balls or zirconia balls, alumina balls, etc. , because small balls are conducive to increasing the friction area between the grinding medium and the material.
effect of the ball ratio of (6). In order to obtain a higher ball grinding energy, a much smaller ball ratio is usually used than a normal ball mill. When loading volume and ball diameter size are certain, the average free course of ball movement depends on the amount of ball loaded. When the ball is too small, the material is less likely to be ground than the ball, and on the other hand, the average free range of the ball is reduced over an hour, which can not make full use of its mechanical force, thus reducing the degree of mechanical chemical reaction.
effect of the ball grinding time at (7). The length of ball grinding time directly affects the composition and purity of the grinding product. Ma amorphoation and crystal transformation of certain metals or alloys are carried out only within a fixed time frame, when the grinding time is too short, the energy accumulation inside the material is too small to destroy its binding price bonds; For mechanical chemical synthesis of inorderable non-metallic materials, ball grinding usually takes a long time.
(8) ball grinding rate. The effect of ball grinding speed on product granularity is similar to that of ball grinding time.
(9) abrasives. Abrasives are chemicals that can significantly improve crushing efficiency and reduce energy consumption during powder preparation, mainly surfactants, dispersants, etc. A small amount of abrasives are added to the ball grinding process to improve the ball grinding efficiency.
of the temperature (10). In the grinding process, due to the friction and impact of ball grinding on the powder, the temperature of the powder will rise, local temperature rise is conducive to solid opposite, but the overall temperature increase will aggravate the material between the reunion and its adhesion with the grinding ball and barrel wall, grinding some organic matter, the temperature is too high will also lead to its decomposition and other phenomena. It is generally believed that the temperature rise of the powder during grinding should not exceed 350K.
source:
, etc. The application of surfactants in the preparation of ultrafine quartz powders
lily. The study of ultrafine quartz powder formation based on ball grinding
high. Natural pulse quartz preparation of high-purity ultra-fine silicon micro-powder and its application research