Tin metal has numerous beneficial uses in many fields such as electronic soldering and food packages owing to its excellent properties, thus it is an integral part of human race development. Therefore, the development of a more efficient method for smelting metallic tin and separating it from natural cassiterite minerals is highly desirable. Presently, among the available separation methods, the flotation technique is undoubtfully suitable for the recovery of cassiterite fines. Unfortunately, numerous challenges associated with flotation techniques affect their efficiency and thus necessary measures have to be put into place to eliminate them. Recent studies have shown that the selection of floatation collectors is one of the key parameters in enhancing the efficiency of the floatation separation technique. This is with regards to common minerals like quartz that are associated with cassiterites. Alternatively, the existence of unavoidable meal ions like lead and magnesium can result in activation of the quartz, but their effects have not been revealed.
Among the available unavoidable ions, magnesium ions are a prevalent one in the pulp solution. Due to its unique properties, it can be absorbed at different levels on the cassiterite and quartz surfaces thus resulting in a total change of the solution chemistry and mineral properties. As such, it undermines the efficiency of the floatation separation of cassiterites. Alternatively, the influence of the interaction between the cassiterites and quartz surfaces and magnesium ions especially on the floatation separation technique has been fully explored.
To this note, Kunming University of Science and Technology scientists: Dr. Qicheng Feng, Dr. Shuming Wen, Wenjuan Zhao and Dr. Haitao Chen investigated the influence of magnesium ions on the separation of cassiterites from quartz through floatation separation method. Fundamentally, the study was based on micro-floatation tests. On the other hand, several techniques including zeta potential measurements, XPS analysis were utilized to further investigate the underlying mechanism of the interaction between the magnesium ions with quartz and cassiterites surfaces. The work is published in the journal, Separation and Purification Technology.
It was necessary to incorporate the solution pH in the micro-floatation tests. The authors observed that regardless of the absence or presence of magnesium ions, the solution pH demonstrated significant effects on the floatation of the cassiterites and quartz. For instance, it was worth noting that the suitable pH values for separation of cassiterites from quartz were ranging from pH 6.8-8.2. Furthermore, the floatability of the minerals, as well as the adsorption of oleate species, was not affected in an acidic environment. However, in strongly alkaline conditions, the adsorption of quartz surfaces increased while that of oleate species decrease thus resulting in overall difficulty in separating the two minerals.
In summary, it was uncovered that the interaction between the O sites of the cassiterites and quartz resulted in the adsorption of the magnesium ions on the mineral surfaces. Consequently, stronger interactions were obtained at high pH solutions as compared to lower pH solutions. Altogether, the study by Kunming University of Science and Technology researchers provided essential information regarding the effects of magnesium ions on the separation of cassiterites from quartz through floatation method and thus will enhance the entire process of recovery of ultra-fine cassiterites particles.
Feng, Q., Wen, S., Zhao, W., & Chen, H. (2018). Interaction mechanism of magnesium ions with cassiterite and quartz surfaces and its response to flotation separation. Separation and Purification Technology, 206, 239-246.Go To Separation and Purification Technology