Metal silicon powder production process
The manufacturing process of silicon powder can be simply described as crushing and grinding from silicon blocks, but obtaining a powder with the required purity and particle size distribution is actually much more complicated.
The first step: raw material selection, which is related to the purity of the final silicon powder. The silicon block used to make the powder is approximately >100mm.
Step 2: Break the silicon blocks into smaller particles, first into 5cm silicon blocks, and then use a roller crusher and linear screen to obtain particles of about 3mm. Repeat this step for <3mm particles.
Step 3: First-level classification of air flow, from -30 mesh to second-level classification
Step 4: Target jet grinding of the +30 mesh particles in step 3, from -30 mesh to second stage classification
Step 5: Start secondary classification from -450 mesh particles, and use cyclone filter bags to collect materials. For particles of 30-450 mesh, use a strong magnetic machine to remove iron.
Step 6: Circular vibrating sieve will use the material obtained in step 5. The particle size range of the silica powder we get here is different. A. Collect -325 mesh for wet laser particle size distribution. b. Other required particle sizes, collection, and testing. C. +120 mesh particles enter step 4. You can change the mesh size at this step to obtain the desired particle size range. If the size range is narrow, you can choose a suitable screen combination here, do some experiments, and you will find a suitable method. There's actually a lot of work to be done here, which is why products with stringent PSD requirements will cost more.
Step 7: Purification. The purpose of this step is to remove elements such as Ca and Al that can be removed by acid.
Step 8: Dry Packaging Steps 1 and 7 are to get the material to the required purity if you need a very narrow PSD.
ZhenAn has extensive experience in controlling PSD. This is a beautiful normal distribution curve from one of our successful projects.