Development status and suggestions of Yunnan copper industry, China
|Location||International Geological Congress,oslo 2008|
|Author||Wu, Yinqian۱; Fang, Weixuan۲; Han, Runsheng۱|
|Holding Date||03 September 2008|
Yunnan Province is abundant in copper resources, but there have not yet been found large- and super-large copper deposits. Due to their distribution in remote mountainous areas, the mines are hard to develop; some state-owned copper mines are facing the issue of resource exhaustion. There have been proven 217 copper deposits (occurrences), and there are 156 occurrences where the copper reserves have been proven, which are spread in 14 regions and prefectures (cities) and 38 counties throughout the province. The proven reserves come up to 9588800 tons; the large and super-large copper deposits with the reserves of more than one million tons include Tangdan at Dongchuan, Dahongshan at Xinping, Yangla at Deqin, and Minle at Jinggu; the medium-sized copper deposits occurred in 24 locations; small-sized copper deposits were found in 127 locations, with the recoverable reserves accounting for 35.96%, 44.22% and 19.82% of the total recoverable reserves, respectively. 77.3% of copper reserves is concentrated in the central, southeastern and western parts of Yunnan, accounting respectively for 12.5% and 7.6%, the copper reserves of other mines scattered here and there account for about 2.6%. The recoverable reserves of the copper mines under operation in Yunnan account for 57.9% of the total in the whole province, the copper reserves of the mines which have not yet been developed and utilized account for 36.1%, and those of the mines which are temporarily difficult to develop and utilize account for 6.1%. The recoverable reserves and average tonnage of the main types of copper deposits in the whole province are: metavolcanic sedimentary copper deposits account for 25%, with an average content of Cu of 0.76%; metasedimentary Cu-bearing siliceous dolomite-type copper deposits account for 39.5 percent, with an average content of Cu of 0.88%; sandy shale-type copper deposits account for 1.28 percent, with an average content of Cu of 1.34%; porphyry copper deposits account for 1.34 percent, with an average content of Cu of 0.63%; skarn-type copper-polymetallic deposits account for 18.6%, with an average content of Cu of 0.5% ~ 1.7%; and copper and nickel ores account for 2%, with an average content of Cu of 0.75% and Ni of 1.23%. The average copper tonnage throughout the province is 0.978%, the recoverable reserves of rich copper ores with copper tonnage > 1% account for 46.1% of the province’s recoverable reserves and account for 14.11% of the country’s recoverable copper reserves, coexisting (associated) copper ores account for 29% of the province’s copper reserves, with more than 76% being mono-copper ores. In the recoverable reserves of the whole province, sulfide ores account for 46.56%, oxide ores account for 30.82%, and mixed ores account for 22.62%. In recent ten years the predicted copper resource reserves of large-sized copper deposits with the tonnage of 100 tons found in the Sanjiang River mineralization zone in western Yunnan are 12203000 tons.