Determining Compressive Strength of Rock
The major conclusion to be drawn from the four series of tests is that reasonable care in preparing specimens and conducting compression tests on a hydraulic machine will provide an acceptable compressive strength value for most applications. For normal uniaxial compression tests, nonparallel ends, end surface texture, steel false end platens, and spherical head friction […]
How to Use Heat to Separate Copper from Steel Scrap
We initiated a program was concerned with the utilization and disposal of steel scrap, as the pollution and unsightliness caused by the accumulation of steel scrap in junkyards. Maybe we could use heat to Separate Copper from Steel Scrap? In the past decade the problem has become increasingly serious; greater amounts of steel scrap are […]
Electrowinning Neodymium
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, […]
Separate Nickel and Cobalt by Electrorefining
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 […]
Copper Hydrometallurgy
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 […]
Recover Copper from Oxides using Iron and Steel Scrap
For the past two decades, about one-third of the copper consumed in the United States has been imported. In order to meet the Nation’s demand, new and improved methods of copper extraction must be found. Ferrothermic extraction is one possibility; the Bureau of Mines undertook this investigation to determine the principles and optimum conditions of […]
Arsenic Assay Determination by Colorimetric Method
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 […]
Chrysoberyl Flotation
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 […]
Copper Leaching Practices
The first large-scale leaching and precipitation of copper was probably at Rio Tinto in Spain about 1752. The method employed comprised open-air water leaching of weathered piles of copper-bearing ore followed by precipitation of the copper by iron. A description of leaching and precipitation of copper at Rio Tinto in the 20th century is given […]
Amalgam Electrorefining of Zinc & Tin
The following conclusions are drawn from the results of the laboratory tests of amalgam electrorefining of zinc and tin: Amalgam electrorefining is a method by which these metals may be refined to total metal impurity concentrations of less than 5 ppm in zinc and 9 ppm in tin. The suitability of metal for amalgam refining […]