Design engineers involved with mine or tunnel construction require knowledge of rock behavior in order to assure economic excavation of rock and stability of underground openings. For many applications, the behavior of a rock is determined from an engineering approach involving rather empirical experiments. A greater emphasis is now being placed on the use of … Read more
In the commercial electrowinning of zinc, zinc oxide is leached from the roasted calcine with an aqueous acid sulfate electrolyte. The zinc-rich solution is purified and then passed into an electrolytic cell where a fraction of the metal is cathodically deposited. The spent electrolyte is pumped from the cell to readjust the zinc concentration by … Read more
The profitable operation of a coal preparation plant under today’s stringent product standards and ever-rising labor, material, energy, and equipment costs requires that the preparation engineer continually strive for maximum recovery of salable coal. Good performance data are a prerequisite to the design of a new plant or to the expansion of existing facilities, and … Read more
Lime and limestone-based SO2 scrubbing processes have demonstrated reasonably good success in removing low concentrations of SO2 from flue gases. While most of the operating problems experienced in the early days of scrubbing have been worked out, problems usually increase and removal efficiency drops with increased amounts of SO2 present in the gas stream. Thiosorbic … Read more
A technique is presented for the economic selection of a slurry pipeline with the aid of a computer. Mathematical models for the flows of homogeneous slurries are utilized. Only the pipeline and its prime movers are considered. Slurry flow properties are first obtained from rheology and/or pipeline data measurements. A rheological model is then selected … Read more
Knowledge of the behaviour of flotation machines had developed and increased considerably over the last few years. Although much work remains to be done on the study of the fundamental processes that influence the collection of hydrophobic particles at an air-water interface, there is enough information to permit the building of realistic models of the … Read more
The present process refers to a method for efficiently obtaining high purity metallic copper from copper ammonium sulfite. Essentially, this process consists of submitting the copper ammonium sulfite to the action of heat and pressure with the object of obtaining by the decomposition of it, metallic copper, ammonium sulfate, sulfur dioxide, and sulfuric acid. Detailed … Read more
The high tension process which separates materials based on relative differences in surface conductivity has been very successful in recovering non-ferrous metals from municipal waste. Aluminum is by far the largest constituent of the total non-ferrous metal fraction; accounting for >95% in most localities. Wire and insulation mixtures from industrial wastes have been treated commercially … Read more
Pre-concentration by sorting is as old as the mining industry. Inevitably waste rock is broken with ore. Separation may take place in the stopes by selective mucking and transport, or selective loading and transport of ore and waste by 12-cu. yd. shovels and 100-ton trucks in large open pit operations. Hand sorting of 1″ to … Read more
Bureau of Mines forecasts of the aluminum situation show that U.S. demand for the metal in the 1960’s increased at a average annual rate of 9.4 percent, with a projected long-term growth rate of 6.5 percent, higher than any other metal. Conversely, the Nation is becoming increasingly dependent on imports for its aluminum needs. Of … Read more