Silicon powder’s manufacturing process can be simply described as: breaking & milling from silicon lump, but it’s actually much complicated in order to get the powder with required purity and particle size distribution.
1st Step: Raw material choosing, this concerns the purity of final silicon powder. The silicon lump prepared for manufacturing powder is about >100mm.
2nd Step: Breaking the lump to smaller granules, first break into 5cm silicon lump, and then use roll crusher & linear screen to get the granules about 3mm. Repeat this step for <3mm granules.
3rd Step: Airflow 1st level grading, get -30mesh to 2nd level grading
4th Step: Target Jet Milling for +30mesh particles from 3rd step, get -30mesh to 2nd level grading
5th Step: Particles with -450mesh from 2nd level grading, use cyclone filter bag to collect the material. For 30-450 mesh particles, removing iron with strong magnetic machine.
6th Step: Round vibrating screen the materials get from 5th step. We get didn’t particle size range silicon powder here. a. Collecting -325mesh, carry out Wet laser particle size distribution. b. Other required particle size, collecting, testing. c. +120mesh particles go step 4. You can change the mesh screen size at this step to get the required particle size range. If the size range requirement is narrow, choose the suitable mesh screen combination here, do some experiments and you will find the right way to do. There are actually a lot of work here, that why price will be higher for products with strict PSD requirement.
7th Step: Purification. This step is to remove Ca, Al and other elements which can be removed by acid.
8th Step: Drying and packing
First step and seventh step are about to get the material with in required purity, sixth step is the most important process if you required a very narrow PSD. Edgetech Industries have rich experience on controlling the PSD. Here’s is a beautiful normal distribution curve for one of our succeed project.