The term 'free from impurities' can be summarized by the crossword solution 'REFINE, ' which means to make something pure or perfect by removing impurities. Refining is a process used in many industries, such as oil refining, metal refining, and sugar refining. It is also used to purify water and other liquids, as well as to remove contaminants from air and soil. Refining is an important part of many manufacturing processes, as it helps to ensure that products are safe and of high quality.