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.
1 st Step: Raw material choosing, this concerns the purity of final silicon powder. The
silicon lump prepared for manufacturing powder is about >100mm.
2 nd 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.
3 rd Step: Airflow 1st level grading, get -30mesh to 2 nd level grading
4 th Step: Target Jet Milling for +30mesh particles from 3 rd step, get -30mesh to 2 nd level
grading
5 th Step: Particles with -450mesh from 2 nd 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.
7 th Step: Purification. This step is to remove Ca, Al and other elements which can be
removed by acid.
8 th 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.
https://www.edge-techind.com/Products/Semiconductor-Elements/Silicon-powder/Silicon-
Powder-Si-powder--783-1.html