Application of laser particle size analyzer in silica powder particle size detection（1）

1. Microsilica powder

Microsilica powder is made from natural quartz (SiO2) or fused quartz (amorphous SiO2 after natural quartz is melted and cooled at high temperature) through crushing, ball milling (or vibration, airflow milling), flotation, pickling and purification, high-purity water treatment, etc. Micro powder processed by advanced technology. Microsilica powder is gray, the particles are spherical, extremely fine, the finest particles are less than 0.01UM, the average particle size is 0.1-0.3UM, it is easy to combine into loose blocks at room temperature, and has high gelling and adsorption capacity. Silicon Micropowder is a non-toxic, odorless, non-polluting inorganic non-metallic material. Because of its excellent properties such as good temperature resistance, acid and alkali corrosion resistance, poor thermal conductivity, high insulation, low expansion, stable chemical properties, and high hardness, it is widely used in chemical industry, electronics, integrated circuits (IC), electrical appliances, and plastics. , coatings, advanced paints, rubber, national defense and other fields. With the rapid development of the high-tech field, silica powder will also enter a new historical development period.

Driven by the rapid development of the domestic microelectronics industry, the usage of spherical silica powder is increasing day by day. Spherical silica powder is mainly used for large-scale integrated circuit packaging. It is also used in high-tech fields such as aviation, aerospace, fine chemicals, rewritable optical discs, large-area electronic substrates, special ceramics and daily cosmetics. It has broad market prospects.

2. Development status of silica powder industry

my country is rich in siliceous raw material resources, including crystal, translucent and milky white vein quartz, metamorphic quartzite, sedimentary quartzite, marine sedimentary quartz sand, fluvial and lacustrine sedimentary quartz sand, pink quartz and other types. With the large-scale development and utilization of siliceous raw materials, the number of high-quality siliceous raw materials is gradually decreasing; in order to meet the requirements for raw materials for silicon powder whose output is increasing year by year, some siliceous raw materials must be refined and purified to reach quality standards before they can be processed. Micronized powder.

According to the survey, the current domestic production capacity of silica powder is about 250,000 tons, mainly ordinary silica powder, while a large amount of high-purity ultra-fine silica powder relies on imports. It is initially predicted that my country's demand for ultrafine silica powder will reach more than 60,000 tons in 2005. Among them, the rubber industry is the largest user, and the coating industry is an important application field with huge potential. Electronic plastic sealants, silicon substrate materials, and electronic and electrical castables all rely on imports of high-purity ultrafine silica powder raw materials. Only the price of ordinary spherical silica powder is 2 - 30,000 yuan/ton, while the price of high-purity ultra-fine silica powder is as high as hundreds of thousands of yuan/ton.

The current domestic production is mainly angular crystalline silica powder and angular ficus fused silica powder. Although it can meet the needs of the domestic market and some are exported, most of the products are of low grade. The high-grade silica powder demanded by the domestic market, such as spherical silica powder and ultra-fine silica powder, still relies on foreign imports.