4.13.1.1 Reserves and Resources

Graphite is one of the dominant minerals in China. Estimates show that the resources of crystalline graphite and cryptocrystalline graphite in China reach 300~ 400 million tons and 100 million tons respectively, making China one of the countries with the richest graphite resources in the world. By the end of 1997, more than 200 graphite occurrences had been found, and 104 graphite occurrences with retained reserves had been explored. Of these, there are 92 retained occurrences of crystalline graphite with retained reserves of 173.78 million tons, which rank first in the world. There are 12 retained occurrences of cryptocrystalline graphite with retained reserves of 44.57 million tons.

Of China's retained reserves of crystalline graphite, reserves of categories B+C account for one-fourth of the total. Geological prospecting has been conduced for most of mines.

Of occurrences of crystalline graphite with retained reserves, 29 occurrences have been utilized, which are distributed in Heilongjiang Province, Shandong Province, the Inner Mongolia Autonomous Region, Henan Province, Hubei Province, Sichuan Province, Yunnan Province and Hebei Province. The total retained reserves exceed 90 million tons, or 52 percent of crystalline graphite retained reserves, which can meet the needs of production of China's flake graphite industry till 2010 and beyond. Furthermore, 63 occurrences, with retained reserves approximating 80 million tons, can be utilized. Of which, 50 ore occurrences with retained reserves of 70.00 million tons are ready for use in the near future. A few occurrences are difficult to use in the near-future.

Among the retained occurrences of cryptocrystalline graphite, five occurrences (1 large-sized and 4 medium-sized occurrences) have been developed .They are distributed in Hunan , Jilin and Shaanxi provinces, with total retained reserves of about 40.00 million tons, accounting for 89 percent of cryptocrystalline graphite retained reserves,and can meet the needs of industrial production of micro-crystalline graphite in China before 2010. The remaining 8 ore occurrences with retained reserves of more than 4.00 million tons are difficult to develop because of poor conditions for development. China is lack of cryptocrystalline graphite occurrences that can be mined in the future.

4.13.1.2 Characteristics

1) Geographic distribution

China's graphite occurrences are widely distributed in 22 provinces (autonomous regions and municipalities). The map of distribution of 69 large and medium-sized ore occurrences with retained reserves is shown in Fig. 4.13.1. China's graphite reserves are concentrated in few areas favorable to mineralization.

Crystalline graphite are dominantly distributed in three regions: eastern Heilongjiang Province, eastern Shandong Province, and northern Inner Mongolia and northern Shanxi Province in northeastern China. There are 21 retained occurrences in a district from Jixi to Luobei in eastern Heilongjiang Province, with retained reserves totalling 110 million tons, or 63% of the national total retained reserves of crystalline graphite. Among them, the Yunshan mine, Luobei County, the Foling mine,Boli County, and the Liumao mine,Jixi City are three exceedingly large mines, with retained reserves of 30~40 million tons for each. It is estimated that the resources of graphite in this district hit some 200~300 million tons, which is really seldom seen in the world. Additionally, dozens of ore occurrences with estimated resources of 30~40 million tons have been found in the area among Pingdu, Lanxi, Laiyang, Wendeng and Mouping in eastern Shandong Province. Of them, 13 occurrences with retained reserves have retained reserves totaling 13 million tons.  Furthermore, dozens of ore occurrences with estimated resources of more than 20 million tons have been found in an area from Alxa Zuoqi eastward, via Baotou and Hohhot to Jining and Xinghe. Of all occurrences, 13 ore occurrences have 5 million tons of retained reserves. In addition, there are 4 retained occurrences in an area from Xinhe southward to the northern part of Shanxi Pro-vince, whose retained reserves exceed 3 million tons. The above-mentioned three regions are the three major occurrences of crystalline graphite in China, and also the three main production areas of flake graphite. Reserves of crystalline graphite amounting to 17 and 10 million tons are retained in an area from southern Sichuan Province to the north of Yunnan Province, and an area from the west of Henan Province to the east of Shaanxi Province. The two areas are also the two main occurrences of crystalline graphite in China, which can provide resources for the establishment of a new production base of flake graphite. Furthermore, there are also large- and medium-sized crystalline graphite mines located in Hebei, Liaoning, Jilin, Fujian, Jiangxi, Hubei, Hainan, northern Sichuan, Tibet, Ganshu and Xinjiang.

Cryptocrystalline graphite mines are mainly distributed in Hunan Province. They are the Heye mine (large-sized) in Guiyang and the Lutong mine (medium-sized) in Cunxian County in the south of the province, and the Sanjian mine (medium-sized), Lengshuijiang, in central Hunan. The retained ore reserves of cryptocrystalline graphite total up to 33 million tons. They are the main occurrences of cryptocrystalline graphite in China and also the major production area of microcrystalline graphite in China, In addition, there are medium-sized cryptocrystalline graphite mines in Panshi of Jilin, Meixian of Shaanxi and Lianping of Guangdong.

(2) Types of deposits

China's graphite deposits may fall into 3 types: regional metamorphic, contact metamorphic and magmatic hydrothermal types. Among the occurrences with retained reserves,

Fig. 4.13.1 Map of distribution of graphite occurrences in China

1. Menduli, Huma County, Heilongjiang; 2. Shujiquan, Qitan County , Xinjiang; 3. Wudangtai, Guyang County, Inner Mongolia; 4. Shibaoqi,Tumd Zuoqi, Inner Mongolia; 5. Denglongsu,Tumd Zuoqi, Inner Mongolia; 6. Miaoguo, Wucuan County, Inner Mongolia; 7. Nanjing, Fengzhen County, Inner Mongolia; 8. Huangtuao No.1 mine, Xinghe County, Inner Mongolia; 9. Sector B, Huangtuao No.18 mine, Xinghe County, Inner Mongolia; 10. Sector C, Huangtuao No.18 mine, Xinghe County, Inner Mongolia; 11. Other mines of Huangtuao, Xinghe County, Inner Mongolia; 12. Aijiagong,Chicheng County, Hebei; 13. Yantong Mountain, Panshi County, Jilin; 14. Fengfu, Xiuyan County, Liaoning; 15. Daenbao, Hengren County, Liaonning; 16. Shanbanjiang, Tonghua City, Jilin; 17. Yunshan, Luobei County, Heilongjiang; 18. Yangbishan, Shuangyashan City, Heilongjiang; 19. Liumao, Jixi City, Heilongjiang; 20. Shichang, Jixi City, Heilongjiang; 21. Anshan,Yongtai, Jixi City, Heilongjiang; 22. Guangyi, Muleng County, Heilongjiang; 23. Foling, Boli County, Heilongjiang; 24. Zhaishan, Muleng County, Heilongjiang; 25. Malanshan,  Mishan City,  Heilongjiang; 26. Gongrongtudingzishan, Jixi City, Heilongjiang; 27. Lingnan, Jixi City, Heilongjiang; 28. Shandaogong, Jixi City, Heilongjiang; 29. The eastern part of Shandaogou, Jixi City, Heilongjiang; 30. Tudingziheping, Jixi City, Heilongjiang; 31. The No.4 ore body, Dangbajing, Alxa Youqi, Inner Mongolia; 32. Tangjia Obo, Minqin County, Gansu; 33. Pinghe, Nanjiang County, Sichuan; 34. Pinghexiaojiawan, Nanjiang County, Sichuan; 35. Tiehe daangou, Yang County,   Shaanxi; 36. Tongyu, Meixian County, Shaanxi; 37. Chongyanggou, Xi'an City,  Shaanxi; 38. Hongcibao, Datong City, Shanxi; 39. Liumudi, Datong City, Shanxi; 40. Jiwojian, Datong City, Shanxi; 41. Yujiahe, Fengxian County, Shaanxi; 42. Nianziping and Cai'ao, Daxigou, Danfeng County, Shaanxi; 43. Hengling, Xixia County, Henan; 44. Xiaodouling, Xichuan County, Henan; 45. Xiaochagou, Zhenping County, Henan; 46, Shancaya, Yicang City, Hubei; 47. Tanjiahe, Yicang County, Hubei; 48. Erlangmiao, Yicang County, Hubei; 49. Liujiazhai, Pingdu City, Shandong; 50. Jiaogezhai, Pingdu City, Shandong; 51. Zhangshe, Pingdu City, Shandong; 52. Liugezhai, Pingdu City, Shandong; 53. Mingchun,  Pingdu City, Shandong; 54. Beishu, Laixi City, Shandong; 55. Nanshu Yueshi,  Laixi City, Shandong; 56.  Nanshu Liujiazhuang, Laixi City, Shandong; 57. Xucun,  Muping County, Shandong; 58. Zhanggezhuang, Wendeng City, Shandong; 59. Qinggu, Zhuogong County, Tibet; 60. Zhongba, Panzhihua City, Sichuan; 61. Xujie, Muding County, Yunnan; 62. Zhongpizha, Yuanyang County, Yunnan; 63. Shanjian, Lengshuijiang City, Hunan; 64. Heye, Guiyang County, Hunan; 65. Lutang, Chenzhou City, Hunan; 66. Xiashan, Jinxi County, Jiangxi; 67. Linggenqiang, Jianyang County, Fujian; 68. Meidong, Lianping County Guangdong; 69. Wuyuan, Qionghai County, Hainan.

the regional metamorphic deposits account for 84% of graphite occurrences and their reserves account for 77% of the total explored reserves. The deposits occur in the Precambrian  me-dium-and high-grade metamorphic series. The ore bodies are controlled by regional deposition and metamorphism. They have a definite stratigraphic position and take stratified, stratoid or lenticular shapes with a length from several tens of meters to hundreds and even thousands of meters and a thickness from several meters to several tens of meters. The sizes of deposits are mainly medium- and large-sized, even superlarge. The ore is of crystalline type, including graphite gneiss and graphite schist. The diameter of graphite flake is from 0.1 mm to several millimeters. The grade of the ore is generally between 3% and 16%. The Liumao deposit in Heilongjiang, Nanshu deposit in Shandong and Xinghe deposit in Inner Mongolia belong to this type and it is the main type of China's graphite deposits. For deposits of this type, crystalline graphite ore is the main raw material for production of flake graphite in China. The contact metamorphic deposits account for 14 % of graphite occurrences and their reserves account for 22% of the total explored reserves. The deposits were formed by metamorphism of coal beds caused by the intrusion of rocks into coal measures. The ore bodies show stratified, stratoid, banded and lenticular shapes with a length from several hundreds to several thousands of meters, and the thickness of a single layer is 1~3 m in general. The deposits is mainly medium- and small-sized. The ores are earthy and compact massive. They are mainly cryptocrystalline graphite with ore grade of 60%~80%. The deposits which belong to this type are the Lutang mine in Hunan and Panshi mine in Jilin. The cryptocrystalline graphite ores in deposits of this type are the main source for producing microcrystalline graphite in China. The magmatic hydrothermal deposits are seldom seen in China. They are only found in Xinjiang and Tibet in western China. They account for only 2% of graphite occurrences and their reserves account for 1% of the total explored reserves. Graphite is crystalline and occurs as medium and fine flakes in graphite granite or in cracks and joints of marble and granite- pegmatite. The deposit size is medium and small and the grade of ore is between 3%~6%. The deposits belonging to this type are the Qitan mine in Xinjiang and others, but they have not been developed and utilized.

(3) Quality of ore

Generally, the grade (fixed carbon, the same hereinafter) of China's crystalline graphite ore is medium, but there are some rich ores and the average grade of ore from various deposits is within 2.34%~34.55%, and the average grade is around 7.4%. There are 15 deposits with an average grade of ore higher than 10%. Their retained reserves account for 46% of the total mineral reserves of crystalline graphite. There are 30 deposits with an average grade of ore of 5%~10%. Their retained reserves account for 37% of crystalline graphite reserves. There are 45 deposits with an average ore grade within 2%~5%. Their retained reserves account for 17% of crystalline graphite reserves. The content of harmful impurities in crystalline graphite ore is not high in general: Fe2O3 3%~10%, S 1%~4% and P2O5 0.02%~0.55%. They can be basically removed after mineral dressing. The flake diameter of crystalline graphite ore is mostly within 0.05~0.1 mm and in some cases can reach 5~10 mm; most of them are medium-sized flakes in general. The graphite deposits with a high proportion of big-flake graphite (0.147 mm) make up one-third of crystalline graphite deposits. The retained reserves account for more than 10% of crystalline graphite reserves; they are mainly distrubuted in Shandong, Inner Mongolia and Hubei. The flakes of graphite ore in most of deposits are dominantly medium-sized (0.074 mm), and graphite flakes in ores of only a few deposits are primarily small-sized (0.074~0.01 mm). The mineral components usually associated with crystalline graphite in the ore are sulfur, titanium and vanadium. Sulfur occurs in pyrite and pyrrhotite; titanium occurs in ilmenite and rutile, and vanadium occurs in roscoelite and calciovolgarnet. The content of these associated components is not high in general, so their recovery value for total use is not high. The dressing performance of most crystalline graphite ore especially the gneiss type, is good. For example, the grade of gneiss ore from the Nansu mine, Beisu mine in Shandong Province and Xinghe mine in Inner Mongolia is only 3%~5%. But the graphite and gangue minerals are comparably large in size and flaky in shape and there are few argillaceous substances, so it is easy to separate them. A satisfactory result can be achieved by the process of floatation. Therefore, these low-grade ores can be widely used and become the main raw materials for producing large-flake graphite in China. The other types of ore possess also a comparably good dressing performance. Only some individual deposits contain refractory ores.

The average grade of cryptocrystalline graphite deposits is within 12.17%~85.39%, with an average grade of around 70.8%. There are 5 mineral deposits with an average grade within 71%~85% and their retained reserves account for 76% of the total retained reserves of cryptocrystalline graphite. There are 3 mineral deposits with an average grade within 60%~70% and their retained reserves account for 13% of the total retained reserves of the cryptocrystalline graphite. The average grade of remainning deposits is within 12%~56%, and their retained reserves account for 11% of the total retained reserves of the cryptocrystalline graphite. The content of the main harmful impurity sulfur is usually relatively low and is mostly within 0.26%~1.16%.  After hand-sorting, crushing and grinding, microcrystalline graphite which accords with the industrial requirements can be produced. Both of flake graphite produced from China's crystalline graphite ore and the microcrystalline graphite produced by cryptocrystalline graphite have good technological performances, and enjoy the high prestige in the international market.

(4) Technological conditions for mining

The technological conditions for mining of graphite deposits in China are simple or fairty good. The open-pit mining method is mostly applied for exploitation of crystalline graphite, but the stripping ratio is high. The thickness of weathering ore zones is usually less than 50 m. The engineering-geological and hydrogeological conditions are simple in the mining areas. In the case of cryptocrystalline graphite deposits, the ore bodies are thin and buried at depth, so most of them need to be mined by the underground mining method. The stability of the wall rocks is relatively poor, and the estimated inflow of water is not large. The engineering-geological and hydrogeological conditions are mostly fair in the mining areas.