As part of a continuing effort to maximize metal recovery from domestic secondary resources, the Bureau of Mines investigated a process for recovering the metallic portion of scrap alkaline batteries. A pyrometallurgical method for recovering nickel and cadmium from Ni-Cd scrap batteries previously developed on a laboratory scale, was scaled up to 25- and 43-pound … Read more
In 1976 CVRD started the investigation of organic binders application for iron ore agglomeration. The ore was mixed in a Eirich Mixer with quantities of Peridur ranging from 0.1 to 0.4% and pellets were prepared in a laboratory disk. At first the results were not satisfactory at all. The wet and dry compressive strength and … Read more
Fluidized-Bed Roasting of Chromium Sulfide The chromium concentrate produced either directly as flotation tails or indirectly as a leach residue is composed primarily of chromium sulfide with chromium comprising about 80 percent of the metal content. Nickel and molybdenum sulfides would be present in the flotation tails along with heavy metal oxides. The leach residue … Read more
Described here is a process for recovering chromium and other metals from superalloy scrap. Laboratory-scale experiments were conducted to test a complex flowsheet utilizing a wide range of extractive metallurgical operations. The novel basis for the process is the formation of a sulfide matte in which chromium is concentrated in a discrete chromium sulfide phase. … Read more
The importance of efficient use of power in autogenous grinding circuits has been greatly neglected. It should be the fundamental factor in considering the design of an autogenous plant to grind a particular ore. The steps in the process used to arrive at a power efficient commercial autogenous plant for a particular ore are outlined. Before … Read more
This Mobile Rock Crusher provides a portable crushing capability to keep conveyor haulage close to the working face and permit more efficient and safer ore handling in low headroom, hardrock mines. A readily portable jaw crusher is used which meets machine size, feed rock size, product size, and throughput requirements for low headroom, hardrock mines. How … Read more
Factors Directly Affecting Molybdenite Flotation: The average molybdenite recovery in the copper concentrator for the first nine months of 1980 was 67.13%. In recent months, there has been approximately an 80% recovery of the molybdenite in the sand and slime rougher floats. The losses in the sand float are due mainly to fine molybdenite particles locked … Read more
The Bureau of Mines once modified a commercial atomic absorption spectrophotometer to rapidly determine trace levels of mercury by cold-vapor atomic absorption spectrophotometry AA. Such diverse materials as ores, mill products, stream water, sediments, and flue dust have been analyzed. A very high dynamic range of 0.2 ng/ml to 1 µg/ml of mercury in solutions … Read more
The fact that over 25% of the original weight of steel liners and balls is discarded as waste is probably one of the factors that has not been considered often. This is particularly true for mill liners, “Mill liners are finished metal products of some precision, they cost two to four times the basic cost … Read more
Leaching of porphyry copper mine strip wastes and low-tenor ores provides a substantial part of U.S. copper needs. Dump leaching requires years to extract part of the copper, and leach dumps often become impermeable owing to precipitation of iron salts which greatly reduces the copper leaching rate. In an effort to improve dump leaching technology, … Read more