Potash Ore Flotation-How does It Work?
The major components of sylvinite ores, sylvite (KCI) and halite (NaCl), are separated by flotation. Since both these minerals are water-soluble, the process is carded out in a saturated brine,6-7 mol/L aqueous solution of NaCl and KCI. C16～C22 primary amines, utilized as a collector, are practically insoluble in water. In commercial potash ore flotation operations these amines are melted by heating up to 70～90℃. They are then neutralized with hydrochloric or acetic acids, and such a hot emulsion/dispersion is introduced to the flotation pulp (which is at room temperature). This is immediately accompanied by the appearance of a white precipitate in the system. As our measurements indicate, the Krafft point of dodecylammonium chloride in concentrated electrolyte solutions is much higher than 80℃, and the Krafft point of C16～C22 amines is substantially higher than that.Introduction of a hot amine emulsion into a pulp, at temperature much lower than the Krafft point for the utilized amines, must cause precipitation of the amines. Some of these species are obviously flotation-active. It is interesting to observe that in summertime, when temperatures are higher,longer chain amines perform better. It demonstrates that the colloidal amine species that precipitate serve as active species in the potash flotation. Therefore, at higher pulp temperatures, when the temperature difference between the pulp temperature and the Krafft temperature of the utilized amine is not sufficiently large, a longer chain amine, the amine with a higher Krafft point, is more efficient.The results reveal that premixing of an alcohol such as MIBC (common frother) with the amine significantly improves flotation performance of the amine. In the presence of such an alcohol the amine disperse system becomes less turbid, and the rheology of the system less non-Newtonian.All this indicates that MIBC, which does not operate as a frother in a potash flotation system, when used as a co-surfactant, enhanees the dispersion of the amine colloidal system. The appearing colloidal species perform as an active form of the collector.
Potash ores Flotation Potash ore flotation Amines Long-chain amines Krafft point Amine colloid chemistry MIBC in potash flotation NaCl-KCI brine
J. S. Laskowski X. M. Yuan E. A. Alonso
Department of Mining Engineering,The University of British Columbia, Canada Bitumen Production Development, SyncmdeCanada Ltd. Fort McMurray, Alberta, Canada B° CGT Rivadavia C.22 M. S, Argentina
国际会议
XXIV International Mineral Processing Congress(第24届国际矿物加工大会)
北京
英文
1270-1276
2008-09-24（万方平台首次上网日期，不代表论文的发表时间）