Pyrometallurgy

How to Extract Uranium from Granite

Despite severe slippage in the growth rate of nuclear power, current estimates still show that the U.S. uranium demand will exceed the production capacity from known resources by about 1981. Projected demands also show that a fourfold to sixfold increase in uranium production will be necessary to meet the expected 1990 requirements. Surging demand and … Read more

Copper Arsenic Smelting

Copper smelting practice has not changed much over the last century. Little attention has been paid to the gas-fired reverberatory furnace because it has traditionally represented only about 10 percent of the total cost of producing copper from its ores. However, the emphasis on air pollution control, fuel shortages, and costs have generated interest in … Read more

Autogenous Roasting of Low Grade Zinc

The operations of the Electrolytic Zinc Co. of Australasia Ltd. involve the preliminary roasting of zinc concentrate from Broken Hill, New South Wales, at a number of acid-making centers on the Australian mainland. The partially roasted material is shipped to the Tasmanian plant where it was formerly re-roasted prior to leaching, but this practice was … Read more

Metallurgical Slag pH Measurement

The correlation of the high temperature chemical properties of slag-metal systems with some easily measured property of either slag or metal at room temperature has been the goal of both process metallurgists and melting operators for many years. There are several rapid methods for estimating various constituents in steel in addition to the conventional chemical … Read more

Volatility and Stability of Metallic Sulphides – Vapor Pressure

The direct reduction of metallic sulphides, as in the precipitation method for lead or antimony, is not a widely used process today. However, it might be employed for the production of a number of metals if the operation were carried out under reduced pressures. Two general procedures are possible; the reducing agent could form a … Read more

Factors Influencing the Performance of Single Retort Underfeed Stokers

Although the efficiency of coal utilization has improved steadily since the turn of the century as a result of continued research and development, little of this increase in efficiency can be credited to improvements in the single retort stoker. There are still numerous problems connected with the burning of coal on this type of unit, … Read more

Magnetic Roasting of Lean Ores

During the past few years a radically new process for the magnetic roasting of iron ores has been investigated and developed by Pickands Mather & Co. and the Erie Mining Co. in the Erie laboratory at Hibbing, Minn. This process, originally devised by Dr. P. H. Royster of Washington, D. C., involves the use of … Read more

Morenci Smelter Arizona

Copper smelters of various kinds have operated in the Morenci district since 1872, but all have been abandoned with the exception of the present Morenci Smelter of Phelps Dodge Corporation, which was completed in 1942. During the five-year period starting in 1937, the Morenci ore body was prepared for open pit mining, pilot mill test … Read more

Self-diffusion in Sintering of Metallic Particles

Two particles in mutual contact form a system which is not in thermo-dynamical equilibrium, because its total surface free energy is not a minimum. If such a system is left for a certain period of time, the bonding of the two particles will take place in order to decrease the total surface area, even though … Read more

Laboratory Preparation of Lithium Metal by Vacuum Metallurgy

As this paper is written, the only method for the commercial production of lithium metal is by the fusion electrolysis of LiCl-KCl mixtures, as first proposed by Guntz. The details of the industrial process have not been made public but Osborg stated that an efficiency of more than 90 pct is obtained with a lithium … Read more