特大片鳞片石墨的分选及其制备的柔性石墨（英文）

Beneficiation of ultra-large flake graphite and the preparation of flexible graphite sheets from it

为了保护近期中国发现的特大片鳞片石墨矿的超大鳞片不受分选加工过程的破坏,设计出"多破少磨+风选+分级磨浮"的联合工艺,对其进行了物理分选,采用碱熔+酸洗法进一步化学提纯,石墨插层化合物法制备出可膨胀石墨,并利用快速加热法得到膨胀石墨。结果显示,提纯后的特大片鳞片石墨的石墨化度高达99.9%,其膨胀石墨产品的膨胀体积高于400 mL/g,随机选取的膨胀石墨单个颗粒的长度大于40 mm,由此膨胀石墨轧制得的柔性石墨电导率高达2.78×10~5 S/m。

A graphite ore with ultra-large flakes (ULFG) found in China (Wulate County, Inner Mongolia Autonomous Region, China), was first jaw-crushed and pneumatically separated to remove rocks, before being subjected to two froth-flotations and finally leached with NaOH and HCl to a purity of 99.9%. The purified ULFG was used to prepare exfoliated graphite by a combined chemical intercalation and rapid heating method and the latter was rolled into flexible graphite sheets of different densities. Results show that the beneficiation and purification methods preserve the graphite crystallites. The purified ULFG has a high degree of graphitization (99.9%). The volume of the ULFG-based exfoliated graphite is more than 400 mL/g, and some randomly selected individual exfoliated graphite particles are larger than 40 mm. A ULFG-based flexible graphite sheet with a density of 1.8 g/cm^3 shows an excellent electrical conductivity of 2.78×10^5 S/m.