The removal of fluosilicic acid ions in acid wastewater silicon etched by potassium salt

2nd International Symposium on Resource Exploration and Environmental Science

生态环境科学

Gao, Ruihong^1 ; Huang, Bing^1 ; Zheng, Huiwen^1

School of Science and Technology Kunming University, Yunnan, China^1

关键词: Chemical precipitation;    Environmental pollutions;    Fluorosilicic acid;    Machining Process;    Potassium sulphate;    Precipitating agents;    Production process;    Silicon materials;   

Others  :  https://iopscience.iop.org/article/10.1088/1755-1315/170/5/052007/pdf
DOI  :  10.1088/1755-1315/170/5/052007

学科分类：环境科学（综合）

来源: IOP

【 摘 要 】

A Silicon material is widely used in various industries, especially in the field of aerospace and solar energy. But a lot of acidic wastewater from silicon etched is produced by machining process of silicon core during polysilicon production process of modified Siemens process, which contains nitric acid, flu silicic acid, and hydrofluoric acid. The waste acid will cause environmental pollution. This research developed a way to make a chemical precipitation reaction of fluorosilicic acid, with precipitant (potassium nitrate, potassium sulphate) in the waste acid. The dilute nitric acid filtrate non-fluorinated is gotten after filtrated the precipitate. The results showed: (1) Potassium nitrate as precipitating agent, the remove flu silicic acid in waste acid and the utilization of the metal ion is the maximum;( 2) The optimal precipitant is potassium nitrate.