Among the many factors involved in rotary kiln efficiency, advantageous use of refractories is of major importance. So far as kiln lining alone is concerned durability is most significant, as shutdowns for repairs are costly in fuel consumption and production losses. Aside from selection of refractories best suited to the widely varying conditions under which … Read more
The recovery of copper from low-grade oxidized and mixed oxide-sulfide copper ores by acid leaching is standard practice in the Southwest. Some ores, however, are unamenable to this method of treatment owing to excessive acid consumption by calcite or other acid-consuming gangue minerals. Other ores present a handling problem because of the presence of clay … Read more
A study has been made of the reaction mechanisms occurring during the salt-roast process to form water-soluble sodium vanadate compounds from the vanadium oxide compounds present in vanadium-bearing ores and concentrates. Two reactions have been identified, either of which lead to water-soluble compounds oxidation of sodium chloride by water vapor and oxidation of sodium chloride … Read more
The design, operation, and performance of an integrated pilot plant for recovering zinc and copper from a complex sulfide ore are described. Metallurgical processing comprised selective sulfate roasting in a fluid bed, leaching in a weak sulfuring acid solution, recovering copper by cementation with scrap iron, air oxidation to remove soluble iron, more-or-less conventional purification … Read more
The Humboldt and its Grate-Kiln System Operation on crude ore is a mixture of cherty specular hematite and magnetite, with minor amounts of martite and sericite. Mineralization varies from coarse to extremely fine grained. The overburden varies from zero to 50 ft. The ore body is approximately 1300 ft. long and varies in thickness from … Read more
Vertical shaft furnace design and operation have their roots deep in antiquity. There is substantial evidence to indicate that iron was reduced from its oxides to serve mankind’s needs long before recorded civilization actually prior to 3500 B.C. For at least 5500 years man has been matching wits with Nature to find better methods of … Read more
The use of solid fuel in shaft furnaces to indurate iron ore pellets was originally considered a necessary evil, which the industry worked long and hard to eliminate. Since then changes have taken place in furnace design and operating practices that have led us to our suggestion that solid fuel additions could again be used. … Read more
The electric arc furnace has characteristics which make it attractive for a number of metallurgical applications. Some of these characteristics are: high thermal efficiency, the possibility of attaining very high temperatures, low off-gas volume compared to fuel-fired furnaces, no impurities are introduced by the heat source, and impurities in only minor amounts are introduced by … Read more
New is a relative term, and when used with reference to a concept as old as shaft kilns can be applied to a number of designs. In this case the design that is the subject of this paper, is known as the ring or annular shaft kiln as developed by Mr. Karl Beckenbach of West … Read more
The purpose of this article is to present design information and operating data on a pilot gas scrubber which is believed to be a new approach for removing noxious gases and particulate matter from the off gases of coal burning power plants and smelters. In addition, gas scrubbers on stream or being developed for coal … Read more