Electrowinning is an electrochemical operation employing an anode and cathode immersed in an electrolytic solution containing sulfuric acid and aqueous copper sulfate. When direct electrical current passes between the cathode and anode through the electrolyte, very pure metallic copper is deposited on the surface of the cathode. The process is conducted commercially in electrolytic cells … Read more
There is a growing interest in the use of fine grinding to produce ultrafine particles for applications such as direct firing of micronized coal. It has been long known that the difficulty of grinding increases dramatically with the fineness of the desired product. To some extent this is a direct consequence of the decrease in … Read more
The present work was undertaken to develop a method to cathodically protect a ball mill to reduce materials loss from mill liners. The essential science of “Cathodic Protection” is to apply a sufficiently negative potential to a metal in a corrosive environment such that the anodic corrosion rate is reduced to a negligibly small or … Read more
The pressure oxidation process is especially suitable for the sulfide type of refractory ores. It includes two stages of operation. First, the refractory ore is subjected to an autoclave oxidation. At elevated temperatures usually above 180°C and in acidic or alkaline medium and pressurized oxygen, sulfide minerals are oxidized for a period of 1-2 hours. … Read more
Processes for gold extraction usually depend on how gold is associated with its environment. Although cyanide leaching remains the overwhelming option for the treatment of gold ores, because of its economy and simplicity, it suffers from certain inherent drawbacks such as toxicity, low leaching rate and its inefficiency of treating certain classes of refractory ores. … Read more
Technology improvements in copper mining operations have been the key factor for increasing productivity. Beyond dump leaching, the industry will increasingly use various heap leach techniques in SX-EW operations in the coming years in order to optimize recovery and maintain low production costs. They include: Finer comminution followed by agglomeration. Finer comminution followed by coarse … Read more
The two size reduction/froth flotation interactions described in this paper are strongly related to optimally using the inherent electrochemical surface rearrangements that occur on selected sulfide minerals, e. g. chalcopyrite, molybdenite, pentlandite, etc. Based on data generated in numerous fundamental studies, it is not surprising that utilizing the electrochemical transformations that occur with grinding could … Read more
The direct conversion of mineral concentrates into useful ceramic materials, without several intermediate processes, is of great interest to the materials community. Recently there has been increased interest in producing ceramic powders with very small sizes (in the order of nanometers) starting with mineral precursor. Thermal plasma processing of mineral concentrates may be used to … Read more
The 150mm (6″) elbows have a S value of 1.7 per Table II. This multiplied by 10 and 6″(150 mm) gives an equivalent length of straight pipe of 102′(31m).
Wire Rope Net Rockfall Barriers A rockfall protection system with the appropriate strength characteristics and height can be designed. Wire rope net rockfall protection barriers of varying designs have been engineered with the proven ability to withstand impact kinetic energies ranging from 81 kJ (30 ft-tons) for the simplest of designs, to a maximum of … Read more