Discussion on Boron Removal Process in Polysilicon
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This post was last edited by yizhuxuan on 2011-11-17 22:36. How can B be removed in polysilicon production? Please advise, thank you
Except for B, 1. distillation purification in a distillation tower, 2. silica gel adsorption.
There should also be activated carbon adsorption for boron removal
Adsorption, hydrolysis, complexation, preheated decomposition, distillation purification.
Phosphorus and boron removal using wet nitrogen, phosphorus and boron removal via membrane separation
Generally, distillation is used to remove impurity B. There is also a hydrolysis method that converts B into boron oxide, but silicon trichloride also hydrolyzes in this process, so it is not very practical.
Reply to 2# yzhang2010: Some B is removed from the slurry residue
Reply to 9# fuwasi: May I ask what exactly this “slurry residue” refers to? I’m not quite sure; please advise. O(∩_∩)O Thank you~~
Reply 10# mian726: I have used it. Once the silica gel becomes saturated with adsorbate or can no longer meet the adsorption requirements, it must be replaced; it cannot be regenerated.
Reply to 11# yzhang2010: The gas produced by FBR enters the quench tower, and the solid-containing liquid discharged from the bottom of the tower is slurry residue, whose main components include STC, metal chlorides, silicon powder, raw silicon, as well as compounds formed by various impurities present in the catalyst, among others