Physical upgrading of graphite is typically achieved with many stages of grinding and flotation to produce a concentrate with approximately 95% carbon grade. An innovative grinding and column flotation process has been developed for efficient graphite upgrading to substantially simplify the process flowsheet and reduce operating costs. In this process, a high-pressure grinding roller (HPGR) and a stirred mill were employed as primary comminution techniques and a nanobubble flotation column as a key separation process. The results obtained with a crystalline flake graphite sample with a carbon grade of 11.15% show that the novel process can produce a concentrate with 94.82% carbon grade and 97.89% recovery from an open circuit of one rougher and two cleaner flotation stages. Scanning electron microscope (SEM) microphotographs indicate that HPGR offers the advantage of more effective protection of graphite flakes during crushing. Grinding test results show that stirred mill could not only protect graphite flakes but also promote the efficient liberation of graphite. Compared with the traditional flotation process, nanobubble flotation can effectively recover ultrafine graphite. The new process possesses a number of important advantages over the traditional method, including substantially higher graphite recovery, greatly simplified process flowsheet, better protection of flake size, reduced reagent consumption and process costs, etc.

石墨的物理升级通常通过多个研磨和浮选阶段来实现，以生产出碳品位约为 95% 的精矿。已开发出一种创新的研磨和柱浮选工艺，以实现高效的石墨升级，从而大大简化工艺流程并降低运营成本。在此过程中，高压磨辊 (HPGR) 和搅拌磨被用作初级粉碎技术，纳米气泡浮选柱用作关键分离工艺。用碳品位为 11.15% 的结晶鳞片石墨样品获得的结果表明，新工艺可以从一个粗选和两个更清洁的浮选阶段的开路生产出碳品位为 94.82% 和回收率为 97.89% 的精矿。扫描电子显微镜 (SEM) 显微照片表明 HPGR 具有在破碎过程中更有效地保护石墨薄片的优势。粉磨试验结果表明，搅拌磨不仅可以保护石墨片，而且可以促进石墨的有效释放。与传统浮选工艺相比，纳米气泡浮选能有效回收超细石墨。与传统方法相比，新工艺具有许多重要优势，包括显着提高石墨回收率、大大简化工艺流程、更好地保护薄片尺寸、降低试剂消耗和工艺成本等。粉磨试验结果表明，搅拌磨不仅可以保护石墨片，而且可以促进石墨的有效释放。与传统浮选工艺相比，纳米气泡浮选能有效回收超细石墨。与传统方法相比，新工艺具有许多重要优势，包括显着提高石墨回收率、大大简化工艺流程、更好地保护薄片尺寸、降低试剂消耗和工艺成本等。粉磨试验结果表明，搅拌磨不仅可以保护石墨片，而且可以促进石墨的有效释放。与传统浮选工艺相比，纳米气泡浮选能有效回收超细石墨。与传统方法相比，新工艺具有许多重要优势，包括显着提高石墨回收率、大大简化工艺流程、更好地保护薄片尺寸、降低试剂消耗和工艺成本等。