The treatment methods applicable to comparatively higher grade ore averaging better than 0.2 ounce gold per ton and having a cutoff grade of about 0.07 ounce gold per ton, include gravity concentration, amalgamation, flotation, cyanidation or direct smelting. Such processes involve high capital investments as well as high operating costs. A conventional cyanidation plant used … Read more
In extractive metallurgy, separation of insoluble solids from solutions is an important economic factor in almost all flowsheets. This separation step can employ sedimentation, filtration (vacuum and pressure), or centrifugation. Since practically all systems require a relatively complete separation, multiple unit, countercurrent thickeners or vacuum filters are generally used. Continuous Countercurrent Decantation In its simplest … Read more
Exploration on Bougainville for copper by Conzinc Riotinto of Australia (CRA) began in 1963 and by 1968, through geophysical, geochemical and diamond drilling methods, an orehody containing nearly one billion tons of ore grading approximately 0.48% Cu. and some gold had been outlined. Bougainville Copper Ltd., the company operating the mine, is 53.6% owned by … Read more
The requirements for controlling air and stream pollution are a most timely subject for all concerned people. The coal industry has taken great measures to reduce both types of pollution. To help eliminate stream pollution and the hazards created by tailing ponds, the coal industry is using centrifugal dewatering equipment. Use of centrifugals to dewater … Read more
The cleaning of coal by the use of jigs is one of the oldest methods of separating coal from its impurities. Although in many situations jigs have been replaced by other methods, by far the largest percentage of coal today is still being cleaned by some form of jigs. Description of the Batac Jig In … Read more
Metallurgical evaluation of autogenous grinding of Anaconda’s Berkeley Pit ores indicated that tonnage throughput increases, at a finer flotation feed size, were possible by converting autogenous mills to steel ball mills. In addition, initial test work showed that the improved grind resulted in slight recovery gains in subsequent flotation processing. Operation of the Autogenous Mills … Read more