工業(yè)上將石墨礦石分為晶質(zhì)(鱗片狀)石墨礦石和穩(wěn)晶質(zhì)(土狀)石墨礦石兩大類。晶質(zhì)石墨礦石又可分為鱗片狀和致密狀兩種。
中國石墨礦石以鱗片狀晶質(zhì)類型為主，其次為隱晶質(zhì)類型，致密狀晶質(zhì)石墨只見于新疆托克布拉等個別礦床中，工業(yè)價值不大。
鱗片狀石墨礦石結(jié)晶較好，晶體粒徑大于1μm，一般為0.05～1.5mm，大的可達(dá)5～10mm，多呈集合體。礦石品位較低，一般為3～13.5%。伴生的礦物有云母、長石、石英、透閃石、透輝石、石榴石和少量硫鐵礦、方解石等，有時還伴有金紅石，釩云母等有用組分。鱗片石墨礦石按其所賦存巖石的巖性不同，分片麻巖型、片巖型、透輝巖型、變粒巖型、混合巖型、大理巖型及花崗巖型等七種，前六種礦石類型產(chǎn)于區(qū)域變質(zhì)成因礦床中，后一種礦石類型則產(chǎn)于巖漿熱液成因礦床中。
穩(wěn)晶質(zhì)石墨礦石一般呈微晶集合體，晶體粒徑小于1μm，只有在電子顯微鏡下才能觀察到其晶形。礦石呈灰黑色、鋼灰色，一般光澤暗淡，具有致密塊狀、土狀及層狀、頁片狀構(gòu)造。隱晶石墨的工藝性能不如鱗片狀石墨，工業(yè)應(yīng)用范圍也較小，礦石品位一般都較高，但礦石可選性差。礦物成分以石墨為主，伴生有紅柱石、水云母、絹云母及少量黃鐵礦、電氣石、褐鐵礦、方解石等。品位一般為60～80%、灰分為15～22%、揮發(fā)分為1～2%、水分為2～7%。
The industry is divided into crystalline graphite ore (flake graphite ore) and stable crystalline (earthy) graphite ore in two categories. Crystalline graphite ore can be divided into two kinds of flake and dense.
Graphite ore in China mainly to flake crystalline type, secondly is cryptocrystalline type, dense like crystalline graphite is only seen in Xinjiang Tuoke Brad individual deposit, industrial value is not great.
Flake graphite ore crystal is good, the crystal size is more than 1 m, the average size is 0.05 ~ 1.5mm, the size of a large amount of up to 5 ~ 10mm, more than a collection. Ore grade is low, generally 3 ~ 13.5%. Associated minerals mica, feldspar, quartz, through amphibole and pyroxene, garnet and a small amount of pyrite and calcite etc., sometimes accompanied by rutile vanadium mica and other useful group. Flake graphite ore according to the occurrence of rock lithology, gneiss, schist, through eclogite, granulite type, mixed type of rock, marble and granite type seven, six kinds of ore type produced in regional metamorphic genesis. After a ore type is produced also hydrothermal deposit.
Stable amorphous graphite ore generally showed a microcrystalline aggregates, crystal grain size is less than 1 m, only under the electron microscope can be observed their crystalline form. The ore was black, steel gray, general luster dim, with dense massive, earthy and layered, lamellar structure. The process properties of amorphous graphite are not as good as that of flake graphite, and the industrial application range is small, and the ore grade is generally higher, but the ore is not available. Mineral composition in graphite mainly associated with andalusite, hydromica, sericite and a small amount of pyrite, tourmaline, limonite, calcite. The grade is generally 60 ~ 80%, ash content is 15 ~ 22%, the volatile is 1 ~ 2%, the moisture content is 2 ~ 7%.