Quartz with a hardness of 7, what are the “points” of ultrafine crushing?


Ultrafine quartz powder is a high-quality neutral inorganic filler, due to its strong acid resistance, stable physical and chemical properties, good light transmittance, high dielectric, high humidity resistance, radiation resistance, excellent high temperature resistance and high Purity, low ion content, low expansion, low stress and other properties, widely used in plastics, coatings, paints, rubber, ceramics, inks and catalytic and gas filter materials and other fields.

Among them, the high-tech industry has quite strict requirements on the purity, particle size and particle size distribution of ultrafine quartz powder. As far as the current crushing technology is concerned, the ultra-fine crushing equipment available for natural quartz minerals includes ball mills, stirring mills, jet mills, vibration mills and various classifiers.


1. Quartz pretreatment (calcination + water quenching)

The hardness of quartz is 7. If other minerals are directly crushed, the energy consumption will be high and the efficiency will be low. Therefore, thermal crushing can be carried out first, that is: calcining-water quenching method.

The quartz is first calcined at high temperature (900-1150°C), and then cooled with water, causing the quartz to undergo rapid “thermal expansion” and “cold contraction”, and a large number of microcracks are generated on the surface and inside the block, thereby reducing its strength. , improve crushing efficiency.


2. Preparation of ultrafine quartz powder by ball mill

The complete production line of ball mill + classifier is more suitable for ultra-fine crushing of quartz. It has the characteristics of high whiteness, good shape and gloss, stable quality indicators, and strong controllability of particle size distribution.

However, since ball mills and classifiers have different functions and focuses, and are usually produced by two companies, there are often differences in concepts such as output, so the matching of the two must be considered in equipment selection and design. If the matching application is unreasonable, it will form functional constraints, high energy consumption, and low efficiency. Proper cooperation can give full play to their respective advantages, so that the advantages of the whole system can complement each other, get twice the result with half the effort, and have high efficiency.


3. Preparation of superfine quartz powder by vibrating mill

The vibration mill has the advantages of low noise, compact structure, small size, light weight, low energy consumption, high output, concentrated grinding particle size, and no pollution. The electronic-grade high-purity ultra-fine silica powder produced is a spherical powder.

Vibration mills generally use alumina as the lining, and the medium is mostly alumina media balls. The vibration frequency directly affects the grinding efficiency of the product as well as equipment loss and energy consumption. Determining the appropriate vibration frequency according to the production capacity and the processing capacity of the classifier is a key factor for efficient and controllable production of products with reasonable particle size distribution. The particle size and output of the product can be adjusted by adjusting the number of impellers of the classifier, the impeller speed, the wind pressure and air volume of the induced draft fan, and the size of the secondary air grid elutriator.


4. Preparation of ultrafine quartz powder by jet mill

Jet crushing technology is one of the most important ultra-fine crushing technologies at present. Guo Xiuping can obtain good crushing effect by using fluidized bed jet mill to crush quartz. In cyclone separator and pulse bag filter, d95= 10μm and d97=6μm two products. Factors affecting the crushing effect of materials mainly include classification current, feeding particle size and classification speed.


5. The application of grinding aids in the super fine grinding of stone

During the fine crushing process of the stone, adding an appropriate amount of grinding aid not only has the effect of grinding aid, but also acts as a dispersant. Commonly used grinding aids are polyacrylamide, sodium chloride, silicate, triethanolamine, sodium dodecylsulfonate, etc.

The amount of grinding aid must be appropriate. Generally, as the dosage increases, the grinding aid effect will increase. After reaching the optimum value, increasing the dosage will make the grinding effect worse.

Why should microsilica powder for electronic packaging be spheroidized?
The application of quartz in all aspects of life