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 […]
High Temperature Electrostatic Precipitator
Industrial precipitators utilizing negative corona operate at maximum voltage to attain highest efficiency in removing finely divided particles from gas streams. Usage, however, is limited to applications at temperatures to about 1,000° F. Therefore, in conjunction with other work for processing coal at high temperatures, the Bureau of Mines sought to extend the applicability of […]
Small Particle Size Minerals Magnetic Separation
By using the magnetization delay factor and the acquired momentum of the particle, minerals may be separated with magnetic susceptibilities within the diamagnetic susceptibility range. Unlike the rotating drum of the induced roll separators , and the feed belt of the cross-belt separators, which feed the particles in close packed moving layers, the vibrating feeder […]
Method for removing aluminum from diecast scrap
Zinc-base die-cast scrap represents the largest single source of secondary zinc. A large part of the die-cast scrap originates from grills, fuel pumps, carburetors, trim, and hardware from scrapped automobiles and other machinery, or from punchings or factory rejects of these components. A typical mixture of die-cast scrap contains from 3 to 5 percent aluminum […]
Joining Refractory Metal Compounds by Hot Pressing
The results of this research indicate that diffusion bonding of refractory metal compounds is a promising method for joining dissimilar materials. Fabrication of graded joins by vacuum hot pressing a mixture layer between two end materials proved to be very satisfactory for the joining of nitrides, carbides, and diborides of zirconium and titanium. Joint evaluation […]
Induction Melting of Titanium
The primary purpose of the research covered by this report was the development of a method for induction melting titanium in a water-cooled copper crucible. The results reported represent findings obtained during the melting of a minimum number of ingots; therefore, only tentative conclusions can be drawn regarding the effects on metal quality of many […]