Cells were designed and successfully operated on a laboratory scale for electrowinning high-purity neodymium, praseodymium, and didymium, as well as the higher melting-point metals, gadolinium, dysprosium, and yttrium. The elements were prepared from their oxides, dissolved in fluoride melts, and deposited as liquid metals on a tungsten cathode. Similarly, alloys of these metals and samarium, … Read more
The electrolytic separation of nickel and cobalt by electrorefining in a molten salt electrolyte was shown to be technically feasible. Nickel-cobalt alloys containing up to 5.5 percent cobalt were electrorefined in a KCl-LiCl-NiCl2 electrolyte to a high-purity nickel metal meeting atomic energy specifications. The amount of cobalt transferred to the cathode deposit was found to … Read more
Copper hydrometallurgy the leaching of siliceous low-grade copper-bearing ores and waste rock that cannot be processed economically by milling and concentrating is an important low-cost process for recovering copper. In the free world, the United States is the principal user of this process, and in 1965 nearly 10 percent of the U.S. production of primary … Read more
Because of its poisonous qualities, the arsenic which is sometimes present in coal and in the atmospheric dust resulting from coal combustion can present a threat to health. As part of its continuing program to reduce health hazards in the mineral industries and to combat air pollution, the Bureau of Mines has surveyed methods for … Read more
In contact-angle research, 10 of the 17 surfactants evaluated proved to be collectors for Chrysoberyl Flotation. With eight of the nine surfactants evaluated as collectors, microflotation recoveries of beryl, feldspar, and topaz were equal to or greater than recoveries of chrysoberyl. Ore-gangue mineral selectivity of all collectors evaluated, except isooctyl phosphate, will be low. Further … Read more
Under the conditions evaluated in this investigation, the extraction of copper from an argillaceous ore was not affected by the addition of ammonia to a cyanide solvent but was entirely dependent on the cyanide concentration. A number of investigators have evaluated cyanide complexes as catalysts for the cyanidation of gold and silver ores. However, cyanide … Read more
The authors investigate the influence of the basicity index CaO/SiO2 on the sintering properties of hematite ore mixtures. The experimentation was performed with three different mixtures of ores from Tazadit, Nimba, Mano-River, Itabira, Marcona, Goa, Mapawa and Cassinga. Increasing the basicity index CaO/SiO2 between 0.1 and 3, chiefly through limestone admixture makes possible to reduce the … Read more
The filter is an apparatus designed to hold the filter medium. At such a medium takes place the entire liquid-solid or gas-solid separation process. Hence, the medium is really the essence of filtration. Yet, the medium, an originally clean porous substance with trapped solids in it, is perhaps the most neglected part of filtration research. … Read more
The presence of radioactivity in uranium mill wastes has resulted in somewhat unique waste disposal methods. In addition to the common problems of disposing of large quantities of solid wastes, neutralizing acids, minimizing dissolved heavy metals, and clarifying all liquid effluents, the uranium mill operator must sample and analyze liquid effluents for micro-micro quantities of … Read more
Many factors, some of which are not easily defined or described, must be considered in the design of a hydraulic backfill system. After participating in the design of several plants, I have a conviction that future refinements in sandfill systems must come in large part, from the merging of good design ideas and information from … Read more