Conventionally, highly corrosive chemicals, such as hydrofluoric acid, are used to dissolve impurities.
传统上, 使用高腐蚀性化学品,例如氢氟酸来溶解杂质。
英语百科
Corrosive substance
A corrosive substance is one that will destroy and damage other substances with which it comes into contact. It may attack a great variety of materials, including metals and various organic compounds, but people are mostly concerned with its effects on living tissue: it causes chemical burns on contact.