refining

the process of removing impurities (as from oil or metals or sugar etc.)

improve or perfect by pruning or polishing

refine one's style of writing

make more complex, intricate, or richer

refine a design or pattern

treat or prepare so as to put in a usable condition

refine paper stock

reduce to a fine, unmixed, or pure state; separate from extraneous matter or cleanse from impurities

refine sugar