Dissolution in Plural Minerals-Water System and Its Effects on Interfacial Phenomena and Flotation of Each Mineral

萤石、方解石、氟碳石等盐型矿物在水中具有较高的溶解度。当盐型矿物共存时，这些矿物产生的离子显著影响彼此的表面和浮选性能。在本研究中，采用作者研制的特殊仪器和方法对混合矿物系统中发生的现象进行了研究。主要结果如下：(1)萤石-方解石二元矿物体系的浮选、zeta电位等指标均与单一矿物体系有所不同。这种差异是由两种矿物在水溶液中溶解的离子种类的影响造成的。这是根据表面沉淀和/或矿物和溶解离子之间的表面反应来解释的。化学热力学计算结果表明，在pH 8.3 ~ 9.3范围内，萤石相比方解石相更稳定，二元矿物体系中方解石表面与萤石相似。在这个pH范围以上，观察到相反的现象。(2) n-油基肌氨酸、十八烷基硫酸钠和n-油脂-1,3-二氨基丙烷二油酸酯（TDO）与盐型矿物组分离子选择性反应，可作为捕收剂用于氟碳铈矿、单氮石、萤石、重晶石和方解石的浮选。在TDO以双离子形式存在的pH范围内，获得了较高的浮选回收率，并对其在盐类矿物上的吸附提供了可能的解释。(3)由于TDO不与浮选矿浆中的主离子发生反应，是一种有效的盐型矿物选择性浮选捕收剂。

Salt-type minerals such as fluorite, calcite and bastnaesite have higher solubilities in water. When salt-type minerals coexist, the ions derived from these minerals markedly affect the surface and flotation properties of each other. In this study, special apparatus and methods developed by the authors were used to investigate the phenomena occurring in the mixed minerals system. The main results were as follows: (1) All results(flotation, zeta potential, etc.) obtained in the binary minerals system of fluorite and calcite differed from those in the singular mineral systems. The difference was caused by the effect of the ionic species dissolved from both minerals in the aqueous solution. This was interpreted in terms of the surface precipitation and/or surface reaction between both minerals and the dissolved ionic species. The results of chemical thermodynamic calculations showed that the fluorite phase was more stable than the calcite phase below pH 8.3-9.3, where the calcite surface in the binary minerals system became similar to that of fluorite. Above this pH range, the reverse phenomenon was observed. (2) N-oleoylsarcosine, sodium octadecylsulfate and n-tallow-1,3-diaminopropane dioleate(TDO) reacted selective- ly with the constituent ions of salt-type minerals, and these surfactants can be used as collector in flotation of bastnaesite, monazite, fluorite, barite and calcite. High flotation recovery was obtained in the pH range where TDO is present as ampho-ion, and a possible explanation for its adsorption on salt-type minerals was presented. (3) Because TDO did not react with main ions in flotation pulp, TDO was an effective collector for selective flotation of salt-type minerals.