ACIDIC OXIDATIVE LEACHING OF CHALCOPYRITE WITH HIGH-FREQUENCY INDUCTIVE HEATING
Abstract
Although a considerable effort is spent for the intensification of various methods of chalcopyrite leaching like high-pressure leaching, use of high redox potential leaching agents (hydrogen peroxide, ozone), use of organic solvents of sulfur, intensive grinding, bacterial leaching, etc. no general method was developed till today. Each process comprises of the individual steps specially developed for the particular technological conditions. From this point of view, it is desirable to improve the efficiency of both the fundamental processes and individual steps as well as the equipment efficiency. Any improvement can bring a noticeable economical effect due to the multiplying effect as the large quantities of raw materials are being processed.
An original idea of use of high-frequency heating for leaching of chalcopyrite in the acidified ferric chloride medium is investigated in this work. A necessary condition is that the heated medium must be electrically conductive what is satisfied for the above leaching system.
The concentration of FeCl3 in the leaching medium was varied in the range of 0.01 - 1.0 M FeCl3 with addition of acid of which concentration was varied in the range of 0 - 1 M HCl.
The high-frequency method allows very fast pulp heating and intensive stirring without mechanical stirrer. Owing to the above facts, the leaching rate is relatively high. An effect of oxidant concentration as well as the acidity on the leaching rate is demonstrated. The positive influence of high-frequency induction field on the leaching process was probably observed as well.
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