Silica powder, a high-performance inorganic non-metallic functional material, is widely used in numerous fields, such as copper-clad laminates, epoxy molding compounds, coatings, paints, rubber, ceramics, cosmetics, drug delivery, and catalysis. Continuous technological advancements and growing demand from downstream industries are driving increasing quality requirements for silica powder.
Silica Powder Demand Trend: Refining
Silica powder is primarily made from natural quartz or fused quartz and is produced through a series of fine processes, including crushing, grading, grinding, magnetic separation, flotation, and acid washing. With the rapid development of high-tech industries such as electronics, 5G, semiconductors, and photovoltaics, the demand for silica powder is growing.
Applications of Silica Powder
High-purity ultrafine silica powder, due to its small particle size, large specific surface area, high chemical purity, and excellent filling properties, exhibits excellent stability, reinforcement, and thixotropy, significantly improving the mechanical properties of materials. Therefore, the ultrafineness and high purification of silica powder are current industry trends. In particular, as electronic products become increasingly thinner and smaller, the demand for silica powder fillers in copper-clad laminates is also increasing.
Silicon Micropowder Ultrafine Grinding Technology and Equipment
Ultrafine powders can be produced using chemical synthesis or physical pulverization methods. Chemical methods produce low yields and complex processes, while physical pulverization methods offer advantages such as low cost and simplicity, making them suitable for large-scale industrial production.
Pulverization methods can be further categorized as dry and wet processes. The dry process generally follows the following steps: feeding → grinding → classification → collection → packaging; the wet process follows the following steps: feeding → grinding → drying → deagglomeration → classification → collection → packaging. Dry products offer a simpler process and lower production costs, making them the general choice of silicon micropowder manufacturers. Compared to dry products, wet products require drying and deagglomeration, resulting in a more complex process and higher production costs. Therefore, fewer companies adopt this process. It is more suitable for ultrafine products with a cut point below 5 microns and requiring surface treatment.
In recent years, significant progress has been made in silicon micropowder ultrafine grinding technology, including various methods such as mechanical pulverization, airflow milling, wet grinding, and ultrasonic pulverization. Common ultrafine grinding equipment includes air jet mills, stirred mills, vibrating mills, and planetary ball mills.
Stirred mills use an agitator to agitate the grinding media, applying impact, shear, and friction to the material. They are suitable for high-hardness materials and can effectively improve the fineness and dispersibility of silicon micropowder. Vibrating mills are more suitable for brittle materials, effectively enhancing the purity and activity of silicon micropowder while reducing defects and impurities. Planetary ball mills use planetary motion to create multi-dimensional movement of the grinding media and material within the mill jar, achieving ultrafine grinding and are suitable for producing high-purity, high-fineness silicon micropowder.
On the other hand, for ultrafine products, the smaller the particle size, the more difficult it is to remove magnetic impurities through magnetic separation, as smaller particles are less likely to attract magnetic impurities. The key to controlling impurities in ultrafine silicon micropowder lies primarily in ensuring low impurity levels in the raw materials, while also preventing the introduction of impurities from the environment during production, preventing wear on equipment and piping, and strengthening impurity removal efforts during production.
Due to the high hardness and toughness of quartz, traditional mechanical grinding methods not only suffer from high energy consumption and low production capacity, but are also prone to introducing impurities and causing secondary contamination. In contrast, airflow milling technology, with its unique operating principle, is an ideal choice for producing high-purity silicon micropowder. This process utilizes high-speed airflow to cause particle collisions, producing a high-purity silicon micropowder with a uniform particle size distribution. Airflow milling improves the dispersibility and reactivity of silicon micropowder, making it suitable for the production of high-purity silicon micropowder for electronic packaging.
In the future, with the continuous innovation and optimization of ultrafine grinding technology, its application in silicon micropowder production will become more extensive. Exploring ultrafine grinding equipment and process flows that do not introduce impurities or generate secondary pollution during the ultrafine grinding and modification process is a key breakthrough in the production of high-purity ultrafine silicon micropowder.