<報文>塩化揮発法に関する基礎的実験 : 塩化カルシウムの酸化反応について

江島,  辰彦, 亀田,  満雄

In recent years, an increasing attention has been paid to the chloride volatilization process with calcium chloride for the recovery of valuable non-ferrous metals from pyrite cinder, copper converter slag, or leaching residue of fluidized roaster calcines. However, there are no systematic study concerning the mechanism and the rate process of chloridizing reaction. In order to clarify these problems, a few foundamental experiments were made on the oxidation of calcium chloride which is considered to be one of the most basic reaction in chloride formation. Rate and mechanism of the reaction were studied by the simultaneous measurements of weight change by means of spring balance of silica and continuous analysis of chlorine gas produced during the experimental run. From the results obtained, it was found that the rate determining process of reaction is the rate of chemical reaction, and that the activation energy of reaction is about 23 kcal for liquid CaCl_2 (about 82 kcal for solid state). An increasing rate of relation was observed when silica or alumina was added to calcium chloride, but the more effective action was due to the addition of silica. Although the presence of moisture accelerated the rate of oxidizing reaction of calcium chloride, a major portion of the produced gas was hydrochloric acid gas which is less effective for the chloridizing reaction of metals compared with chlorine gas. Because the materials consisting of many constituents are generally subjected to the actual chloride volatilization process, it is very difficult to deduce the multiple effects of these constituents for the chloride formation of non-ferrous metals, nevertheless, contributions to the chloridizing reacting may roughly be estimated from the present results.

<報文>塩化揮発法に関する基礎的実験 : 塩化カルシウムの酸化反応について

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