GYPSUM

Gypsum is a mineral of calcium sulphate in the category of non-metallic sulphates. Gypsum is generally a name of the two minerals gypsum and anhydrite. Gypsum is a  dihydrate calcium sulfate (CaSO₄?2H₂O), also called dihydrate gypsum, hydrate gypsum or soft gypsum. Anhydrite is an anhydrous calcium sulfate(CaSO₄). The two kinds of gypsum are frequently associated with each other, and may transform to each other in certain geological processes. 

The application fields of gypsum are quite wide. It is mainly applied in the production of building materials. About 93% of gypsum in China is used as the cement retardant, and less commonly it is applied for making building manufactured products and cementing materials. In the papermaking, paint, rubber, chemical, plastics and textile industries, gypsum is used as a filler. In the agriculture, gypsum is used to produce fertilizers and agricultural chemicals. In the sulfur-deficient areas it is used to prepare sulphuric acid. Gypsum can also used in many fields, such as pharmacy, food industry, molding and artware making. 

Since the Tang Dynasty (618~907 AD) in China gypsum had been successively exploited in Fangxian County and Yingcheng, Hubei and Shanxi, Gansu, Shandong, Jiangsu, Shaanxi and so on. At the beginning of the 20 century the Yingcheng mine, Hubei firstly developed. Nevertheless, up to 1949, the total gypsum output of the country was only 16,000 tons. After 1949 the gypsum industry in China started to develop rapidly. In some old mines the production was expanded and a number of new mines were built. Up to the 1980's the distribution of gypsum production was basically rationalized. In 1997 there were 295 gypsum mining and processing enterprises all over the country with an annual production of gypsum of 26.62 million  tons.

4.18.1 Resources

4.18.1.1Reserves and Resources

The gypsum resources in China are abundant. More than 600 gypsum occurrences have been found in the country. According to the estimated data of the Geological Research Institute under the State Administration for Building Materials Industry of China in 1986 the gypsum resources of category E in China were 665.8 billion tons. Those of category F reached 7,649.2 billion tons. By the end of 1997, there were 171 occurrences (79 large, 35 medium-sized, 57 small) with retained reserves. Their retained gypsum reserves of categories B+C+D amounted to 57.661 billion tons, with which China occupied first place in the world. 

Among the retained gypsum reserves in China, the reserves of categories B+C are 4.2 billion tons, accounting for 70% of the total reserves. Exploration or detailed reconnaissance has been carried out in most exploiting deposits. The proportion of reserves of categories B+C is quite high. A small part of the deposits just have reserves of category D. Among the occurrences with retained reserves, 72 are producing ones  with retained ore reserves of 7.8 billion tons, accounting for 14% of the total retained reserves. They are mainly distributed in Qinghai, Hubei, Jiangsu and Shandong, Hebei, Shaanxi, Guangxi, Sichuan and so on. The retained reserves can meet the needs of gypsum industrial production up to 2010 and in a period of time to come.  65 gypsum occurrences can be selected to be mined, with retained ore reserves amounting to 9.45 billion tons, accounting for 16% of the total retained reserves. They are mainly distributed in Inner Mongolia, Hunan, Ningxia and Hubei, Henan, Shanxi, Anhui, Guangxi, Shandong, Yunnan and so on. There are 34 occurrences, which are difficult to mine in the near future, with retained ore reserves amounting to 40.41 billion tons, accounting for 70% of the total retained reserves. They are mainly distributed in Shandong and Tibet, Chongqing, Anhui, Qinghai, Yunnan, Inner Mongolia, Sichuan, Hebei and so on.

4.18.1.2 Characteristics

  Gypsum deposits in China are widely distributed in 24 provinces (municipalities, autonomous regions). The distribution of 114 large and medium-sized gypsum occurrences with retained reserves is shown in Fig. 4.18.1. Among the retained reserves, except for those which are difficult to mine in the near future, the ore reserves which are being mined and can be selected to be mined in the near future amount to 17.2 billion tons. Their distribution situation is as follows: 30% of the total reserves are distributed in South-central China. They are mainly distributed in Hunan and Hubei. And they are also distributed in Guangxi, Henan and Guangdong. The major producing large and medium-sized mines are in Yingcheng, Jingmen and  Dangyang of Hubei, Shimen and Shaodong of Hunan, Sihui and Xianning of Guangdong and Qingzhou of Guangxi. The Yingcheng mine, Hubei, having a long history gypsum mining, is the key producer of fibrous gypsum in China. Hunan and Hubei provinces both are the key gypsum producing areas in China. There are large and medium-sized deposits in Lixian County and Linli of Hunan, Hepu of Guangxi and Lushan and

Fig.4.18.1Map of distribution of gypsum occurrences in China
1.Kumtag iron ore mine, Hami City, Xinjiang (by-product); 2. Neimatai, Sizhiwang Qi, Inner Mongolia; 3. Rongguan, Dengda County, Liaoning; 4.Huolianzhai, Benxi City, Liaoning; 5. Dongre, Erdaojiang District, Tonghua City, Jilin; 6. North section, Xiasiping, Tonghua County, Jilin; 7. Dayangcha, Jiangyuan County, Jilin; 8. Zhengbeishan, Linze County, Gansu; 9. Dulantai, Alxa Zuooi, Inner Mongolia; 10. Suji, Otog Qi, Inner Mongolia; 11. Suji first section, Otog Qi, Inner Mongolia; 12. Nage, Otog Qi, Inner Mongolia; 13. Taiqingzhao, Hangging Qi, Inner Mongolia; 14. Yipanzishan, Beishansi, Xining City, Qinghai; 15. Xiejia, Wangzhong County, Qinghai; 16. Jiucai Gou, Pingan County, Qinghai; 17. Beijiading-Yaoshui Gou, Ledu County, Qinghai; 18. Periphery of Xiaogou mirabilite mine (by-product), Huzhu County, Qinghai; 19. Xinchuang-Majiayahuo, Minghe County, Qinghai; 20. Huoshaocheng, Tianzhu County, Gansu; 21. Lujia Gou, Tianzhu County, Gansu; 22. Mayingpu, Tianzhu County, Gansu; 23. Shijiagou, Tianzhu County, Gansu; 24. Xiaohongshan, Zhongwei County, Ningxia; 25. Hejiakaozhi, Dongxin County, Ningxia; 26. Wadaozi, Xixiang County, Shaanxi; 27. South Ore Section of Longmenjia, Quxian County, Sichuan; 28. North Section of Nonglepianyazi, Qu County, Sichuan; 29. Mountains Nos.¢ñand ¢òof Geliaogou, Taiyuan City, Shanxi; 30. Mountain No.1, Geliaogou, Taiyuan City, Shanxi; 31. Jinsi Temple, Taiyuan City, Shanxi; 32. Ximenwai, Lingshi County, Shanxi; 33. Dawang, Lingfeng City, Shanxi; 34. Jinwang, Lingfen City, Shanxi; 35. Langqiu, Xiangfen County, Shanxi; 36. Shanghuangguanjiao, Lucheng City, Shanxi; 37. Dongnan iron ore mine (by-product), Huyu, Wuan City, Hebei; 38. Zheshan iron ore mine (by-product), Wuan City, Hebei; 39. Guozhun, Xingtai County, Hebei; 40. Beishengzhuang, Xingtai County, Hebei; 41. Shuangbei, Longyao County, Hebei; 42. Beixiyao, Dawenkou, Taian City, Shandong; 43. Lingwen, Dawenkou, Tai'an City, Shandong; 44. Zhujiazhuang natural sulphur mine(by-product), Tai'an City, Shandong; 45. Huafeng, Ningyang County, Shandong; 46. salt deposit of Dawenkou Basin(by-product), Dawenkou, Shandong; 47. Qiaqiao, Pingyi County, Shandong; 48. Pingyi Basin, Shandong; 49. Dige, Zaozhuang City, Shandong; 50. Shishuyuan, Dige, Zaozhuang City, Shandong; 51. Xinji, Lushan County, Henan; 52. Dongjia ore section, Sihu ore district, Pixian County, Jiangsu; 53. Tiefu ore section, Sihu ore district, Pixian County, Jiangsu; 54. Xingdun ore section, Sihu ore district, Pinxian County, Jiangsu; 55. Anpeng, Tongbai County, Henan; 56. Dingyuan County gypsum mine, Anhui; 58. Xisun, Sanheji Township, Dingyuan County, Anhui; 59. The north ore section, Dingyuan County, Anhui; 60. Maojia Hill, Gaodianzi, Dangyang City, Hubei; 61. Xiejia Hill, Gaodianzi, Dangyang City, Hubei; 62. Mine No.2, Yanjiachong, Machengpu, Jiangmen City, Hubei; 63. Geji, Jingmen City, Hubei; 64. Zilingpu, Jiangmen City, Hubei; 65. Shenji, Jingmen City, Hubei; 66. Machengpu, Jingmen City, Hubei; 67. Changjiagang-shengjiatan, Yingcheng City, Hubei; 68.Longwangji, Yingcheng City, Hubei; 69. Yunmeng mine, Yunmeng County, Hubei; 70. Luohe iron ore mine (by-product), Lujiang County, Anhui; 71. Dabaozhuang pyrite mine (by-product) Lujiang County, Anhui; 72. Tanggou, Wuwai County, Anhui; 73. Zhoucun, Nanjing City, Jiangsu; 74. Wulidun, Jiangxia District, Wuhan City, Hubei; 75. Chengchao West District (by-product, West of Line 15), Ezhou City, Hubei; 76. Huangshi City gypsum mine, Hubei; 77. Donghu copper ore mine (by-product), Guichi City, Anhui; 78. Zhag'yab County, Tibet; 79. Neiba, Markam County, Tibet; 80. Huolayaneng, Markam County, Tibet; 81. Zhongnong, Markam County, Tibet; 82. Paomaping ore section, Jinding lead-zinc Mine (by-product), Lanping County, Yunnan; 83. Wudasi, Kangding County, Sichuan; 84. Dawei, Emeishan City, Sichuan; 85. Zhenqi, Leshan City, Sichuan; 86. Tianchi, Huaying City, Sichuan; 87. Bazhiyang, Jiangbei County, Chongqing; 88.Lunadian, Xiaojia County, Yunnan; 89. Jianbaoshan, Midu County, Yunnan; 90. Xiaojin, Wuding County, Yunnan; 91. Xiaojian (by-product), Luquan County, Yunnan; 92. Majiagou, Panxian County, Guizhou; 93. Taipingpu, Puding County, Guizhou; 94. Yisa, Honghe County, Yunnan; 95. Dalingdou, Hepu County, Guangxi; 96. Qinling, Qinzhou City, Guangxi; 97. Shangwutong, Shimen County, Hunan; 98. Wujiayu, Lixian County, Hunan; 99. Hekou, Linli County, Hunan; 100. Yisuhe, Xiangtan City, Hunan; 101. Zimenqiao, Shaofeng County, Hunan; 102. Shaodong gypsum mine, Shaodong County, Hunan; 103. Huangbiqiao, Shaodong County, Hunan; 104. Dahetang, Lianshitang, Shaodong County, Hunan; 105. Changle, Shaoyang County, Hunan; 106. Zhuhuita calcium salt nitre ore section (by-product), Zhashanao salt mine, Hengyang City, Hunan; 107. Weitong glauberite mine (by product), Hengnan County, Hunan; 108. Wushishan, Yongxin County, Jiangxi; 109. Luotang, Guixi County, Jiangxi; 110. Xingning Gypsum Mine, Xingning City, Guangdong; 111. Mafang, Sihui City, Guangdong; 112. Dalangshan, Sanshui City, Guangdong; 113. The periphery of Dalangshan, Sanshui City, Guangdong; 114. Yanbu, Guangzhou City, Guangdong.

Tongbai of Henan can be selected to be mined as well. 27% of the total gypsum ore reserves are distributed in North China, and mainly in Inner Mongolia, Hebei, and Shanxi. The main producing mines are those large and medium-sized ones in Taiyuan and Lingshi of Shanxi and Xingtai and Longyao of Hebei. Shanxi Province is the key gypsum producing area in China. There are also large and medium-sized deposits in Otog of Inner Mongolia and Xiangfen and Lucheng of Shanxi, which can be selected to be mined. 24% of the total are distributed in Northwest China. They are mainly distributed in Qinghai, Ningxia and Shaanxi, Gansu and Xinjiang. The main producing mines are the large and medium-sized mines in Xining of Qinghai, Zhongwei of Ningxia, Xixiang of Shaanxi and Tianzhu of Gansu. The 2 provinces of Gansu and Ningxia are the main gypsum producing areas in China. There are also large and medium-sized deposits in Dongxin of Ningxia, Minghe of Qinghai and so on, which can be selected to be mined. 15% of the total are distributed in eastern China. They are mainly distributed in Shandong, Jiangsu and Anhui, Jiangxi. The main producing mines are large and medium-sized mines in Taian and Pingyi of Shandong, Nanjing and Pei County of Jiangsu and Dingyuan of Anhui. Shandong and Jiangsu provinces both are the main gypsum producing areas. There are also large and medium-sized occurrences in Zhaozhuang of Shandong, Dingyuan of Anhui and Guixi and Yunxin of Jiangxi, which can be selected to be mined. 3% of the total are distributed in southwestern China, they are mainly distributed in Yunnan and Sichuan and less commonly in Guizhou and Chongqing. The main producing mines are large and medium-sized mines in Wudin and Honghe of Yunnan and Qu County of Sichuan. Sichuan Province is also a major gypsum producing area in China. There are also large and medium-sized deposits in Midu of Yunnan, Huayin of Sichuan and Puding and Panxian of Guizhou, which can be selected to mine. 1% of the total are distributed in Northeast China. They are distributed in an area from Tonghua of Jilin to Dengta of Liaoning. Most of the large and medium-sized deposits in Jiangyuan and Tonghua of Jilin and Dengta of Liaoning have already been mined. Only medium-sized and small occurrences in Xiasiping, Tonghua of Jilin are available for development. 

There are 3 genetic types of gypsum deposits in China. They are sedimentary, epigenetic and hydrothermal metasomatic ones. The sedimentary type is the most important one for gypsum deposits. The deposits of this type are mainly of large and medium sizes. The retained reserves of deposits of the type make up 99% of the total retained reserves. The type may be divided into 2 subtypes: marine sedimentary deposits and lacustrine sedimentary deposits. The retained reserves of marine sedimentary deposits accounts for 14% of the total retained reserves. The ore-bearing rock sequences are Lower-Middle Triassic, Permian, Lower Carboniferous, Middle Ordovician and Lower Cambrian carbonate or clastic formations. The ore beds are several hundred to several thousand meters long and several meters to more than a hundred meters thick. The ore grade is between 65% and 95%. To this subtype belong gypsum and anhydrite deposits in Jiangsu, Sichuan, Shanxi, Jiangxi, Gansu, Ningxia, Liaoning, Jilin. The retained reserves in lacustrine sedimentary deposits account for 85% of the total retained reserves. The ore-bearing rock sequencces are mainly Tertiary Lower Quarternary clastic carbonate rock formations. The ore beds are several dozen to several thousand meters long and a single bed is several tens centimeters to several tens of metres thick. The ore grade is between 55% and 90%. To this subtype belong gypsum and anhydrite deposits in Hubei, Inner Mongolia, Ningxia, Hunan, Shandong, Yunnan. Epigenetic gypsum deposits were formed by migration, deposition, filling of dissolved primary ores or those undergoing secondary changes with limestone into fractures or caves of ore-bearing rocks. They are distributed in Hubei, Hunan, Guangxi, Yunnan and Guizhou. The gypsum deposits of hydrothermal metasomatic are anhydrite deposits occurring in contact zones of Yanshanian intermediate intrusive rocks with Lower Triassic limestone in Echeng of Hubei and in Lujiang of Anhui. also anhydrite deposits occurring in early Yanshanian intermediate extrusive rocks. 

The age range of gypsum deposits in China is wide. They occurred in almost all geological periods. Among them the Middle Cambrian period, Middle Ordovician, Early Carboniferous, Early-Middle Triassic and Cretaceous-Paleogene are the 5 major minerogenetic epochs of sedimentary deposits. 

Most gypsum deposits in China are large and medium-sized ones. There are 26 super large deposits (with reserves of 0.2~30 billion tons). Of all retained reserves, those of anhydrite deposits make up 60%, and those of gypsum deposits account for 40%. Nevertheless, of all retained reserves which are being mined or are available for exploitation in the near future, gypsum deposits account for 80%. Generally no dressing is needed for gypsum ore in China. Ore grade in general belongs to medium or high one. The average ore grade (Ca£ÛSO₄£Ý?2H₂O + Ca£ÛSO₄£Ý) is generally higher than 55%, which meet the requirements for the cement retardant. In all gypsum deposits being mined and available for mining in the near future, the retained reserves with an average ore grade of higher than 75% are more than 5 billion tons, which can meet the requirements for architectural gypsum. 

88% of gypsum deposits in China are mined for gypsum alone. There are also nearly 20 deposits in which gypsum is mined as a by-product in ores containing saline minerals or sulfur, iron, copper, lead, zinc and so on. Gypsum in most of these deposits has not been mined and utilized yet. 

The transportation conditions for gypsum deposits which are being mined or available for mining in the near future are generally good. The conditions of engineering geology and hydrogeology in the mining areas are mostly simple and about the average.