Effect of polymers on compressive rheology of inter-particle structures in mineral processing systems.

随着加工矿物粒度的减小，选矿难度急剧增加。同样，随着处理过的颗粒尺寸的减小，后续的固液分离也会受到影响。因此，在这样的细颗粒系统中，水与细矿物颗粒的分离和回收仍然是一个主要问题。由于目前开采的矿石通常需要超细粉碎以实现有效的分选，行业似乎必须开发新的方法来处理不断增加的细粒。*拟议研究计划的总体目标是提高我们处理这些加工问题的能力，以及是否可以更好地利用聚合物来克服这种与粒度相关的可分选性限制。聚合物吸附的影响，无论是物理的还是化学的，对颗粒间结构的性质的影响将被确定。还需要调整和开发新的测试方法，以获得关于细颗粒物系统的微观和宏观性质的信息。缺乏适当的现场测试方法在很大程度上导致我们无法观察沉积物结构的内部，以及这些结构对各种处理的反应。在一个新的应用中，实验计划将涉及X射线计算机断层扫描(CT)，以可视化和分析沉积物的内部结构，以及在固液分离过程中沉积物结构在压力下的变化。沉积物性质随时间的变化也可以用激光后向散射进行监测。后向散射法允许沿沉积物高度进行固体含量的估计。用流动电位法研究沉积物中颗粒/絮体的表面电荷特性。通过压缩流变学研究沉积物对外力的抵抗力和沉积物释放的水量，结合CT结果，可以对絮凝矿物悬浮液的脱水行为提供新的见解。测试的聚合物将使用超速离心法和粘度技术进行表征。预计所有工作都将在不同的pH值和离子强度条件下，使用一系列不同的聚合物-矿物系统进行。*选矿行业经常因为尾矿设施对环境的影响以及不太理想的水回收做法而受到审查。然而，在可预见的未来，水仍将是用于分离细矿物颗粒的所有技术的过程介质。人们相信，这一计划的成果将有助于更智能、更有效地利用水资源。这些数据也应该适用于其他使用聚合物和处理固液悬浮液的行业。

The difficulty of mineral separation sharply increases as the particle size of the processed minerals decreases. Similarly, subsequent stages of solid-liquid separation also suffer as the sizes of the treated particles decrease. As a result, separation and recycling of water from fine mineral particles remains a major problem in such fine particle systems. As presently-mined ores often require ultra-fine grinding for efficient separation, it appears that the industry will have to develop new approaches to deal with the increasing amounts of fine particles.**** The overall objectives of the proposed research program are aimed at enhancing our ability to deal with these processing issues, and whether polymers can better be utilized to overcome such particle size-related separability limits. The effect of polymer adsorption, whether physical or chemical, on the properties of interparticle structures will be determined. A need also arises to adapt and develop new testing methodologies to obtain information about the micro- and macro-properties of fine particulate systems. The lack of appropriate in-situ testing methods is largely responsible for our inability to look inside sediment structures, and how those structures respond to various treatments. In a novel application, the experimental program will involve x-ray computed tomography (CT) for visualizing and analyzing internal structures of sediments, and how the sediment structure changes under pressure during solid-liquid separation. Changes in sediment properties as a function of time can also be monitored using laser light back-scattering. The back-scattering method allows estimation of the solids content to be made along the sediment height. The surface charging characteristics of particles/flocs in sediments will be probed with the streaming potential method. The resistance of sediments to external forces and the amount of water released by the sediments will be researched through compressive rheology, which in combination with the CT results should provide a new insight into the dewatering behavior of flocculated mineral suspensions. The tested polymers will be characterized using ultracentrifuging and viscosity techniques. It is envisaged that all the work will be performed using a range of different polymer-mineral systems, under various pH and ionic strength conditions.**** The mineral processing industry often comes under scrutiny for the environmental impact of tailings facilities, and for the less-than-optimal water recycling practices. Nevertheless, water will still be the process medium in the foreseeable future for all technologies used for separation of fine mineral particles. It is believed that the results of this program will contribute to smarter and more efficient approaches to water utilization. The data should also be applicable to other industries using polymers and handling solid-liquid suspensions.***