Circular 70 — Recovery of Valuable Minerals from Pegmatitic Ores

By Roshan B. Bhappu and Maurice C. Fuerstenau, 1964, 29 pages

The recovery of valuable minerals, such as beryl, spodumene, lepidolite, and microlite from pegmatitic ores has presented a challenge to mineral benefication engineers in the past. This difficult problem has been solved through a systematic study of the reposnse of these minerals, individually and in combination with each other, to varioius collectors, pH, activators, and depressants. It has been shown that lepidolite and other micaceous minerals can be removed by a conventional amine float at pH = 2.5. Beryl, spodumene, and spars are depressed at this pH by sulfate ions introduced into the system from the sulfuric acid used for pH adjustment. Finally, the selective floation among spodumene, beryl, and microlite is accomplished through the use of flouride or hydrosulfide ions and gravity separtion. Both the theoretical and practical aspects of the floation procedures are discussed, and a workable flowsheet is presented for the economic expoitation of these difficult-to-treat ores.