石墨物理提纯技术研究进展

    Research progress on physical purification technology of graphite

    • 摘要: 天然鳞片石墨作为关键战略资源,其提纯技术直接决定资源利用效率,探究高效环保的提纯技术至关重要。为系统探究天然石墨物理提纯技术的发展现状与应用潜力,对现行物理提纯技术进行梳理,内容涵盖了传统物理技术(浮选法)和新兴联用技术(纳米气泡技术、超声辅助石墨提纯技术和水射流解离技术),对比总结各类技术的基本原理、优点及存在问题;进一步展望了未来石墨提纯技术的发展方向,聚焦于提高纯度上限、低成本工业化、低碳工艺优化,而这些方向对应的技术突破,正是我国未来石墨物理提纯技术发展迫切需要解决的难题。因此,本文提出一种全新的联用技术——空化-浮选耦合石墨提纯技术。该技术是空化与浮选结合的多级循环处理工艺,其基本原理是叶轮在水介质中高速旋转会产生空化现象,空化产生的力作用于石墨颗粒,使其表面附着的灰分矿物质脱落,从而实现提纯。本文进一步开展了初步探究实验,对比单次浮选与单次空化-浮选的提纯效果,结果显示空化-浮选的提纯效果更优。粒度测试表明,空化处理具有破碎剥离效果;SEM、XRF和XRD测试进一步验证了空化-浮选技术良好的提纯效果;证明了该技术能够实现提升纯度、简化工艺、降低成本兼顾环保价值的目标,也为解决石墨提纯难题提供了一种新思路。

       

      Abstract: As a critical strategic resource, natural flake graphite’s purification technology directly determines resource-utilization efficiency, making it essential to explore efficient and eco-friendly purification techniques. To systematically investigate the development status and application potential of physical purification technologies for natural graphite, this paper reviews existing physical purification methods, including conventional physical techniques(flotation) and emerging combined technologies(nanobubble technology, ultrasonic-assisted graphite purification, and water jet dissociation technology). The fundamental principles, advantages, and limitations of each technique are compared and summarized. Furthermore, future development directions of graphite purification technologies are prospected, focusing on raising the upper limit of purification grade, low-cost industrialization, and low-carbon process optimization. Technical breakthroughs in these aspects represent urgent challenges for the advancement of physical graphite purification technologies in China. Accordingly, this paper proposes a novel combined technology: cavitation-flotation coupled graphite purification technology. This multi-stage cyclic treatment process integrates cavitation and flotation. Its basic principle lies in that high-speed rotation of impellers in aqueous media generates cavitation. Forces induced by cavitation act on graphite particles to strip off ash-forming minerals attached to particle surfaces, thereby realizing purification. Preliminary experimental investigations are further performed to compare the purification performance of single flotation and single cavitation-flotation. The results demonstrate superior purification efficacy of cavitation-flotation. Particle-size tests reveal that cavitation treatment exerts fragmentation and exfoliation effects. SEM, XRF, and XRD characterizations further verify the favorable purification performance of cavitation-flotation technology. It is demonstrated that this technology can achieve the goals of purity improvement, process simplification, cost reduction, and environmental friendliness, offering a new insight for addressing challenges in graphite purification.

       

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