Material efficiency: rare and critical metals . Philosophical .
Mar 13, 2013 . Granted, the high grade ores are being used up. . That literature focuses on the major materials, such as iron and steel, . mercury, molybdenum, nickel, niobium, rubidium, silicon, silver, tin, titanium, tungsten and zinc. process for gold recovery), to recover the copper, gold, silver and palladium, for all of.Live Chat