How to Tell Fumed Silica from Precipitated Silica

Here we have fumed silica and precipitated silica in front of us, We will find it’s difficult for us to distinguish them just by their appearance.

What can we do?

1. PH Test

Make fumed silica and precipitated silica into 4% concentration water suspension respectively, and test by pH meter.

  • one pH value is around 4, another one is around 7.
  • The 4 pH one is fumed silica, and the 7 pH one is precipitated silica.

2. Determination of Iron ions

Due to differences in raw materials and manufacturing process, precipitated silica has higher content of iron ions.

Make fumed silica and precipitated silica into standard solution, add chromogenic agent respectively.

The precipitated silica solution is turning red while fumed silica solution remains colorless.

Hello, Customers

My name is Van, I’m the business manager of HIFULL, I have been in Fumed Silica Industry for more than 10 years. Feel free to contact me. I’m happy to provide you the best service and products.
Business Manager