中国石墨加工技术的发展及与石矿业

2025-03-27

Graphite has good characteristics including high temperature resistance, electrical conductivity, thermal conductivity, lubricity, chemical stability and thermal shock resistance, etc. It’s an important raw material not only in aerospace, defense and military industry, high-end equipment manufacturing, new energy, new materials, information technology, energy conservation and environmental protection industry, but also for traditional industrial fields such as refractory materials, electrode brushes, pencils, casting, sealing, and lubrication. China is the country with the largest graphite reserves and output in the world, and its graphite beneficiation technology and equipment have long been in a leading position in the world. At present, there are more than 50 graphite beneficiation companies in my China, and more than 200 various processing companies, forming a production capacity of about 1.6 million t/a graphite concentrate. From 2014 to 2019, the global graphite concentrate production has been hovering at 900 to 1.2 million t/a, of which China accounted for about 60% of the global output. It can be seen that the in-depth research on graphite beneficiation technology and equipment is of great significance to enhance the international influence of Chinese graphite products.

石墨选矿技术的研究进展

与大多数矿物不同，结晶石墨的选矿要求既要获得高品位的石墨精矿，又要尽可能保护石墨矿物的晶体结构。因此，石墨选矿技术和设备具有独特的特征。

破碎技术

由于石墨矿石的硬度一般为中等硬度或中等硬度到软，因此破碎过程相对简单，通常采用三阶段开路、两阶段开路或甚至单阶段开路的破碎工艺，有些则采用三阶段闭路破碎流程。

磨矿技术

为了保护石墨片的晶体形态并提高精矿的大片率，研究人员进行了大量研究工作，可以总结为磨矿介质的形状、磨机的形式、浮选机的形式以及浮选工艺。在大量研究和生产实践的基础上，目前已形成广泛使用的技术。

选矿/加工技术

Crystalline graphite mostly adopts closed-circuit process of multi-stage regrinding of coarse concentrate, multi-stage beneficiation, and sequential (or concentrated or segmented concentrated) return of middling’s. Under normal circumstances, the beneficiation recovery rate can reach more than 85%, and some mines can reach more than 90%; the grade of concentrate is usually more than 90%, and the grade of fine flake graphite concentrate is usually more than 93%. Some mines have also tried the centralized or partially centralized regrinding process. In the 1980s, most graphite processing plants in my China used 3 to 5 regrind and redressing processes for coarse concentrates. At present, most of the graphite processing plants use more than 8 regrind and redress processes, and some even use 11 regrinds. The main reason for using multiple grinding is to protect the large scale graphite flakes from damage and increase the yield of large flake graphite in the concentrate.

根据原矿的特征，结晶石墨选矿工艺的类型可以分为以下几种类型：

1. 粗大片石墨矿。这种矿的特征是石墨片大且浮选性好。初级石墨颗粒大小一般为0.6-2毫米，固定碳通常为1%-10%，并含有一定量的云母。选矿主要是保护大片，精矿品位控制在约87%或更高，以提高大颗粒的产率，最终的精矿+80目含量为40%至60%。
2. 中片石墨矿。这种矿的石墨片中等大小且浮选性好。初级石墨颗粒大小为0.2到0.6毫米，固定碳通常为4%到15%，云母含量低。主要是保护石墨片，以最大化大片的产率。精矿的品位可以控制在86%～90%之间，+100目的含量约为40%～60%。
3. 细片石墨矿。这种矿的石墨片小且浮选性中等。初级石墨颗粒大小为0.03到0.2毫米，固定碳含量为6%到15%。产品的重点是提高纯度，但也必须保护大片，即使是通过降低回收率。精矿的品位一般在90%左右，部分高达98%，+100目的含量在5%和20%之间。这种矿应该加强选矿工艺，选矿采用多级磨矿和多级分离工艺。
4. 隐晶质石墨矿。隐晶质石墨的晶体大小通常小于1微米。因此，通常通过浮选来提高精矿品位的效果并不明显。目前，中国隐晶质石墨的开采量不大，通常采用手选的方法以获得更高品位的石墨精矿。湖南陆塘石墨矿的原矿品位为65%～68%，手工精选的精矿品位为70%～88%，尾矿的品位低于60%。南方石墨公司已建成年产20万吨微晶石墨的生产线。项目第一阶段的微晶石墨回收率大于92%，精矿品位约为82%。

凭借数十年的石墨加工技术研究与学习的经验，与石（上海）矿业科技有限公司现拥有一支专业的技术团队，致力于推进石墨加工厂的加工技术，以保护大片并提高精矿品位。与石（上海）矿业科技有限公司可以为石墨矿企业提供完整的石墨加工厂支持！