一、矿物及可浮性通常在石墨矿石中除含石墨外,还有石英、黄铁矿、方解石等金属矿和脉石矿物,有时还有一部分稀有元素如金红石、锆英石、钛铁矿等。此外,国民经济各部门,对石墨各级产品要求含炭量很高,如制坩埚用的石墨要求灰分不得超过10～15%,电极石墨要求的纯度更高,铸造石墨灰分应小于30%。而自然界里所遇到的石墨矿石,含炭 First, the mineral and buoyant Usually graphite in addition to graphite, but also quartz, pyrite, calcite and other metal and gangue minerals, and sometimes some rare elements such as rutile, zircon, ilmenite Wait. In addition, all departments of the national economy require very high carbon content for graphite products at all levels. For example, the graphite used for crucibles should not exceed 10-15% of ash content, and the purity of electrode graphite materials should be higher, and the graphite content of castings should be less than 30%. The natural graphite ore encountered in the charcoal