Concentrateur Gravimétrique
Concentrateur Knelson Cet appareil ameliore la separabilite des particules par gravimetrie en travaillant dans un champ centrifuge (60 fois G) plutot que dans le champ de la pesanteur. II comporte un bol de forme conique inversee muni de rainures dans sa parois interne (pour retenir les particules) et qui tourne a un vitesse tres elevee […]
Table a Secousses
Principe de fonctionnement de la Table a Secousses: Lorsqu’un film d’eau coule sur une surface plate inclinee, l’eau pres de la surface est retardee par la friction. La vitesse augmente vers la surface libre de l’eau. Si des particules de minerai sont introduites dans l’eau, les particules plus petites ne se deplacent pas aussi vite […]
ISL In-Situ Copper Leaching
In researching ways to improve the recovery of minerals from in situ leaching operations. Such operations are amenable to recovering low grade ore, reducing many of the typical mining operations cost, and presenting environmental benefits. Hydraulic properties and characteristics of copper ore are investigated to assess the impact of permeability on flow capacity during in-place, […]
Electrowinning Neodymium – Electrolytic
A rapidly expanding market for Nd-Fe-B permanent magnets has created intense interest in development of a new process for producing neodymium metal. The current industrial process is calciothermic reduction of neodymium fluoride (NdF3), which entails reacting calcium metal with NdF3 at 1,200° to 1,400° C in closed tantalum crucibles. The process was initially developed for […]
Effect of Nonionic Surfactants on Chalcopyrite Leaching
Duncan, Trussell, and Walden reported the effect of nonionic surfactants on the Thiobacillus ferrooxidan leaching of chalcopyrite. The tests were conducted in 250-mL Erlenmeyer flasks containing minus 325 mesh chalcopyrite and a modified 9K medium at pH 2.5 and 35° C. The hypothesis tested in adding the surfactants was that the presence of a surfactant […]
Effect of Chalcopyrite Leaching Additives
Previous U.S. Bureau of Mines (USBM) research on the leaching of chalcopyrite with ferric sulfate [Fe2(SO4)3] demonstrates that surfactant additions enhance chalcopyrite (CuFeS2) leaching and that surfactant selection has a significant impact on the initial leaching rate. Additions of chloride ion (Cl-) are also known to enhance chalcopyrite leaching, although a review of the literature […]
Recovery of Mercury from Electrical Wastes
As part of its mission to reduce the environmental impact of minerals processing, the U.S. Bureau of Mines (USBM) investigated the characterization and treatment of Hg-contaminated wastes from an electrical-parts manufacturing plant. A literature search showed various hydrometallurgical methods for recovering Hg have been investigated on a laboratory scale, but there has never been a […]
HCl Hydrochloric Leaching of Manganese Silicate Ore
An estimated 17 million mt of manganese are contained in domestic manganese-bearing silicate resources, yet domestic production is insignificant compared with the quantity of manganese imported yearly into this country for consumption. The projected U.S. consumption of manganese in 1990 was expected to be about 680,400 mt with the majority of total demand being supplied […]
Electric Arc Furnace Steelmaking using Scrap
This investigation is part of the Bureau of Mines program to develop technology that emphasizes the reuse of recycled, economically important materials, including iron and steel scrap. In addition, the research helps meet the basic objective of substituting abundant domestic materials for imported strategic commodities such as fluorspar. Scrap Preheating Of the 84.6 million st […]
Elution of Mercury Silver and Gold from Resins
Numerous low-grade gold-silver ore deposits throughout the Western United States have been developed in the past few years. Cyanide leaching and carbon adsorption are generally used to recover the gold. Precious metals and other adsorbed metals are eluted from the carbon with dilute caustic cyanide solutions. The elution process requires elevated temperatures and in some […]