There is a wide difference in the floatability of coals of different rank, and even of the same rank, depending on whether they have been freshly mined or allowed to oxidize. Also, differences in floatability, presumably due to oxidation, may occur within a particular seam because of ground water percolating through the coal bed or … Read more
One aim of metallurgy research within the Federal Bureau of Mines is the advancing of metals and minerals processing technology to foster the overall goal of maintaining an adequate supply of minerals and metals to meet national economic and strategic needs. This report describes part of a research effort aimed at increasing the utilization of … Read more
During electrolysis, metal was produced from solid lead chloride in contact with the cathode rather than from lead in solution. Relatively high current densities—up to 300 amp/ft²-were possible when operating in this way. Primary lead is now usually produced from sulfide concentrate by a smelting process that involves sintering, blast furnace reduction with carbon, and … Read more
As part of a larger study to identify factors influencing the practical operating life of wire rope used on large draglines in surface coal mining, field trips to operating surface coal mines were made during late 1975. Wire rope performance information was obtained from personnel at thirteen mine sites west of the Appalachians. Data Acquisition … Read more
Ideally, mill circuits should be controlled so that excessive random disturbances are reduced in frequency and amplitude. It is difficult to derive an objective measure of the effectiveness of any chosen control strategy. Often, the response of the circuit to pulse or sinusoidal disturbances is used as a measure of the effectiveness of control. Linear … Read more
In reviewing available vacuum filtration equipment in this paper, several types of filters have been included which are probably not familiar to operators in the mining industry. However, it was felt that these units might be of interest in the event that an application should arise for the filtration of a product in the future … Read more
In Situ leaching for the recovery of uranium from low grade sandstone deposits is one of the newest technological advances in the mineral industry. It is rapidly developing into a commercially feasible mining system which has economic, environmental, and social advantages over conventional mining systems. Because of the current uranium shortage, development of In Situ … Read more
The equipment which is used in solvent extraction plants for contacting the organic and aqueous phases and separating the same is varied. Most common to the industry is the mixer-settler unit which, in itself, can be of varied design; but many new innovations in contacting and separating equipment have been recently introduced or are now … Read more
Low recoveries of cassiterite are obtained by gravity concentration of lode deposits, particularly if the cassiterite calls for fine grinding of the ore. And it is precisely this finely ground ore that is the cause of the low recoveries. The possibility therefore of upgrading the ore by flotation has been of great interest to the … Read more
Mechanism of Size Reduction The spectrum of comminution mechanisms in a mill range from shattering of the rock by imposition of a load to abrasion by surface contact with other rocks. Since SAG represents a combination of autogenous and ball milling, a better understanding of the mechanism of the comminution process in a SAG mill … Read more