To meet these uranium demands, larger, lower grade, and refractory ore bodies will need to be exploited. The utilization of these ores will require the development of new and improved processing technology. In its program of Advancing Minerals Technology, the Bureau of Mines is investigating innovative methods for recovering minerals and metals from low-grade and … Read more
Increasing usage of aluminum and competition for foreign reserves of bauxite have created a renewed interest in the development of domestic aluminum resources. Investigations were conducted into producing aluminum from domestic clays, anorthosite, and alunite in order to assure a continuing supply in the face of an uncertain world situation. Processes were developed that were … Read more
The effect of various ion concentrations on uranium absorption from a sodium carbonate solution by a strong-base, anion resin was investigated by the Bureau of Mines in support of its objective to help assure an adequate uranium supply for future needs. The studies were conducted to improve the recovery of uranium from in situ leach … Read more
Resin-In-Pulp The Federal American Contactor is currently being used by Federal American Partners, Union Carbide, and Western Nuclear. The system has a single stage per tank as in the Porter System. It is not a fluidized bed system but a system in which the resin is maintained in a slurry suspension by mechanical agitation. The … Read more
Research in recent years has been directed toward seeking methods of metal extraction which are less labor and energy intensive, less costly in capital investment and are less insulting to the environment. Chemical metallurgy offers much toward meeting these criteria. Hydrometallurgy offers innovations in copper dump leaching, new developments in in-situ leaching of copper and … Read more
A jig tailing with gold content ranging from 0.33 to 0.43 oz/ton was leached in weak cyanide solution with extractions of up to 97 pct in 24 hours. By countercurrent batch leaching studies and laboratory pilot plant operation, minus 10- plus 20-mesh and minus 6- plus 16-mesh coconut carbon were loaded to 700 oz/ton of … Read more
A part of the U.S. Department of the Interior, Bureau of Mines, research program is to develop improved or alternative methods for metal recovery from domestic resources, and thereby help to insure an adequate supply of mineral raw materials for the U.S. economy. Since about 80 pct of the nickel requirements are imported, research studies … Read more
Leaching Chalcopyrite is the holy grail for hydrometallurgists (Leachers), difficult to leach as the sulfur forms a layer over the mineral and makes the leaching slow. Having said that, it is not 100% not leachable, not unusual for ore dumps (low grade) containing chalcopyrite to be placed under leach but report low recovery +/-30% TCu … Read more
Solution mining followed by solvent extraction-electrowinning (SX-EW) is one possible way to economically extract copper from ore bodies which cannot otherwise be profitably exploited. Published costs for the unit processes of SX and EW are out of date especially in view of the newer reagents now available and the newer circuit configurations. This paper updates … Read more
In the cyanide process, gold and silver are dissolved from crushed ore as double alkali-metal cyanides, from which they may be precipitated by such positive metals as sodium (amalgam), aluminum, or zinc, or by electrolysis. Two extreme conditions may be noted. Some works, especially slime plants practising decantation, use a relatively large volume of solution—possibly … Read more