How to Steam Cure Bricks
In the processing of numerous types of minerals to recover their values, enormous tonnages of gangue materials are produced and discarded to storage areas near the processing plants. In this country, primary copper producers alone produce 125 million tons of tailings per year. Zinc, lead, asbestos, and roofing granule operations also produce large tonnages of […]
How to Clean Titanium Alloy Scrap
Recycled titanium scrap is mixed with titanium sponge for ingot production and, therefore, plays an important role in the production of mill products. Clean and segregated scrap is recycled fay producers that regard their scrap-recovery procedures as proprietary. Unless a rigorous procedure is observed for segragating titanium scrap by alloy content, the scrap is not […]
How to Recover Metals from Zinc Smelter Residue
Primary smelting of zinc in horizontal retort distillation furnaces leaves a residue consisting of the following: unburned carbon, iron as metal shot and stringers, copper inclusions in the iron as metal and as sulfides, silver in solid solution in the copper, and glassy slag. After removal from the retorts and cooling, the residue is crushed […]
Use of Cryogens Liquid Nitrogen to Recycle Scrap Metals
Scrap such as insulated copper wire, small motors, automobile tires, and nonferrous concentrates from automobile shredders contains materials that become brittle at low temperatures and other materials that remain malleable. Crushing of the chilled materials to shatter the embrittled portion followed by magnetic separation, screening, and/or gravity separation was studied for recovering the individual components. […]
Mica Beneficiation
In recent years, more than 99 percent of the domestic mica produced has been scrap and flake mica (mica which does not meet specifications for sheet mica and which is used for producing fine-ground mica). There has been a continued increase in mica production for several years. The 1969 production of scrap and flake mica […]
Chlorine Leaching Copper
The high reactivity of chlorine as an oxidizing agent in leaching ore has long been recognized, but chlorine has not been extensively used because of high costs and because of the corrosiveness of acid chlorine solutions. As early as 1848, the use of aqueous chlorine solution was proposed for extracting values from gold ores, and […]
Copper Cementation on Iron
Cementation of copper onto iron is a historically old process for recovery of copper from leach solutions. Although about 13 percent of the Nation’s primary copper production is from cementation, this process remains more of an art than a science. The literature on cementation is extensive, but a thorough review shows that until about 1965 […]
Rare Earth & Hydrogen Oxygen Fuel Cell
The activity of rare-earth compounds for catalysis of the hydrogen-oxygen reaction is of interest because of their possible use for electrocatalysis of the cathode reaction of a hydrogen-oxygen fuel cell. Although platinum metal has been widely used as a fuel cell catalyst, its high price and relatively limited supply prohibit its use in truly large-scale […]
Tailings Pond Seepage
This report is a sequel to earlier Bureau of Mines investigations which indicated the need for a seepage environmental research investigation relative to the slime zone of a typical tailings pond. In the previous studies, slope stability and location of phreati.c surface were of prime concern; consequently, only the outer portion of the pond embankment […]
Silver Barite Treatment Method
The Calico mining district in California contains extensive deposits of low-grade silver ore. The deposits cover a large area and constitute an important silver reserve if difficult concentration problems can be solved. The deposits also contain barite, which, if recovered as a byproduct during treatment of the silver ores, might contribute to the economic returns […]