tí​liàn HSK7

to refine

提炼 提煉 tí​liàn
to refine verb
To extract and purify a substance from raw materials or compounds using physical or chemical methods; to process minerals or ore.

In short, this means that humans have been mining and refining gold for more than 6,600 years.

to abstract; abstraction
To extract the essence or most important parts of something, such as a language or a theme, by removing the unnecessary or false elements

Frequency

Movie subtitles
1.40 per million appears in 1% of films
Written text
4.43 per million

Details

HSK 2.0
Level 6
HSK 3.0
Level 7

Sources