Chrysocolla flotation by the formation of insoluble surface chelates

Pure chrysocolla is floated with chelating agents that form insoluble complexes with copper at ambient temperature. Complete flotation is obtained with potassium octyl hydroxamate as collector at pH 6. Flotation response is enhanced with increased temperature when low additions of h ydroxamate are involved. A natural ore was floated with 0.4 lb per ton octyl hydroxamate at pH 6.5 and 58OC, and a flotation recovery of 76% was obtained with a concentrate grade of 31.6% copper.