Influence of particle shape and roughness on the induction period for particle-bubble attachment
Influence of particle shape and roughness on the induction period for particle-bubble attachment
复制标题
DOI：
--
复制
发表时间：
2012
期刊：
影响因子：
--
通讯作者：
D. I. Verrelli;W. Bruckard;P. Koh;M. Schwarz;B. Follink
中科院分区：
文献类型：
--
作者：
D. I. Verrelli;W. Bruckard;P. Koh;M. Schwarz;B. Follink
在浮选界，人们认为某些颗粒形状比其他颗粒形状更容易“漂浮”。这通常归因于颗粒形状或粗糙度对实现颗粒与纸浆中的气泡之间的附着所需的诱导期的影响。到目前为止，这种测量还不能容易地隔离对各个浮选子过程的影响。相比之下，我们的实验装置，CSIRO Milli-Timer，使我们能够直接观察粒子-气泡相互作用的过程，并通过高速视频记录的附件，从而提供了一个直接测量的诱导期的附件。为了评估颗粒形状对诱导时间的影响，我们使用了两种不同的甲基化硼硅酸盐玻璃颗粒-球体和有角的“玻璃料”-在一系列紧密尺寸的部分。在这样做的时候，我们注意考虑到其他因素的影响，可能会影响诱导时间，如极角的滑动开始，和接近速度。将这些参数记录为每个相互作用的变量，并使用多元非线性回归进行校正。我们的研究结果说明了粒子形状的重要性，诱导期与角粒子表现出的诱导期是一个数量级低于那些领域。此外，诱导期被认为是减少与增加粒子速度，或动能的方法，但增加的轨迹接近的限制，只是擦过气泡。矿物加工中的颗粒形状主要取决于矿物类型和所采用的研磨类型。本文所呈现的结果表明，除了颗粒尺寸之外，还应注意从研磨操作获得的颗粒的形状。
Within the flotation community a belief has developed that some particle shapes are more ‘floatable’ than others. This is usually attributed to an influence of particle shape or roughness on the induction period required to achieve attachment between the particles and the air bubbles in the pulp. Up to now, such measurements have not been able to readily isolate the effect on individual flotation subprocesses. In contrast, our experimental apparatus, the CSIRO Milli-Timer, enables us to directly observe the process of particle–bubble interaction and attachment by means of a high-speed video recording, thus providing a direct measure of the induction period for attachment. To assess the influence of particle shape on induction time we used two varieties of methylated borosilicate glass particles — spheres and angular ‘frit’ — in a range of tightly-sized fractions. In doing this, we take care to account for the influence of other factors that could affect the induction time, such as the polar angle of sliding commencement, and approach velocity. These parameters are recorded as variables for each interaction, and corrected for using multiple nonlinear regression. Our results illustrate the importance of particle shape on induction period, with angular particles exhibiting induction periods that were an order of magnitude lower than those of spheres. Furthermore, the induction period was seen to decrease with increasing particle velocity, or kinetic energy on approach, but increased as the trajectory approached the limit of just grazing the bubble. Particle shape in mineral processing is a consequence chiefly of the mineral type and the type of grinding employed. The results presented herein indicate that attention should be paid to the shape of particles obtained from the grinding operation, besides particle size.