In the field of extractive metallurgy, mineral processing, also known as ore dressing, is the . For instance, stamp mills were used in Samarkand as early as 973. They were also in use in medieval Persia. By the 11th century, stamp mills were in.
Apr 11, 2017 . Preparation by ore dressing includes the concentration of the valuable . supply, commercial affiliations of the company, royalties on processes and . Free milling ores in which most of the gold may be amalgamated with.