アルキル硫酸塩あるいはアルキルベンゼン, スルフォン酸塩を捕収剤として用いたときの黄鉄鉱, 黄銅鉱の浮遊性について

Abstract

The collecting action of alkyl sulfate or alkylbenzene sulfonate against pyrite was studied from the view point of the separation of chalcopyrite from pyrite. The results were summarized as follows.1. Pyrite floated in acidic pulp, even in the case where only frother was used, because pyrite surface was oxidized to hydrophobic elemental sulphur. The pH region where pyrite floated extended towards more alkaline side, as the addition of this type of collectors increased. But, pyrite did not float above pH 8, even by the addition of the appreciable amounts of these collectors2. The native floatability of chalcopytite was varied by the difference of the method of preparation of mineral samples. Chalcopyrite which was dried in vacuum after wet grinding floated perfectly below pH 12 by using frother alone. While, chalcopyrite after wet grinding did not float above pH 10, but, it floated in pH value of about 12 by the addition of small amounts of this type of collectors.3. There was no substantial difference in adsorption mechanism of these collectors between pyrite and chalcopyrite. The amounts of adsorption decreased with increasing pH when pH exceeded a certain value below which the adsorption amounts of collectors remained constant. Also, in the case of constant pH value, the amounts of adsorption rapidly increased at critical concentration of collector through the formation of hemimicelles.4. The floatability of pyrite increased remarkably even in the collector concentration less than that of hemimicelle formation.From the above results, it was concluded that the role of this type of collector was to enhance the difference in native floatabilities of chalcopyrite and pyrite by collector adsorption, thus making it possible to separate chalcopyrite from pyrite at lower pH value than in xanthate flotation. This will be regarded as one of the characteristics of the flotation in which alkyl sulfate type collector is used.