Dams and Earthquakes

Asia: Wenchuan quake has limited impact on mining

Engineering and Mining Journal
July 11, 2008

The numbers from the May 12 earthquake in China are staggering. As this edition of E&MJ went to press, the death toll in Sichuan Province had climbed to 68,000 with 288,000 injured and more than 5 million people homeless. The earthquake was measured at 7.9 on the Richter scale and centered in Wenchuan County. Rock slides in the mountainous region had blocked rivers creating “quake lakes” and residents were
living in fear of temporary dams giving way.

News reports from the interior of China remain somewhat vague. The Sichuan-Chongqing region specifically produces lead, zinc, and aluminum. The output of zinc concentrates in 2007 in Sichuan reached 130,000-140,000 metric tons (mt). Sichuan is the third largest production area for vanadium ores. The earthquake forced most zinc and
vanadium mines in Sichuan province to close and most of the zinc and aluminum smelters to halt production.

Indirectly, the earthquake also destroyed the electrical infrastructure and transportation networks. At least 10 zinc smelters in Sichuan, Gansu and Shaanxi are confirmed to be closed. They have a combined total annual capacity of more than 500,000 mt, which
represents about 11% of China’s total zinc smelting output.
The largest zinc smelter in Sichuan Province, Sichuan Hongda Co.Ltd., was forced to close. It has an 80,000-mt capacity. A smelter owned by Hanzhong Bayi Zinc Industry Co., Ltd. with an annual capacity of 120,000 mt in Gansu is also closed because of the shortage of electricity. The company’s smelter is 400 miles from Chengdu. “For
safety concerns, the local government suggested temporarily closing the mill and we now have closed 70% of its capacity,” the company said in a statement. “The smaller zinc smelters nearby also suspended the production and their total capacity is about 150,000 tons.”

A total of eight power plants in Sichuan closed because of the earthquake and the transmission system has been disrupted. Eight transformer stations in Sichuan and nearby Shaanxi have also closed.

The Chinese metal research institution Antaike Information Development Co., Ltd. estimates that power could be restored by mid-June. If mines are more heavily damaged, the smelters will obviously remain idle. Aluminum smelters are facing similar, indirect problem with power shortages. When production will start again depends on the power supply and how much damage the earthquake did on the power system, said a spokes person from Sichuan Aostaral Aluminum Co. Ltd. The annual aluminum smelting capacity in Sichuan exceeds 720,000 mt. Aostaral Aluminum’s annual capacity is 125,000 mt in Sichuan. The region’s largest smelters, Sichuan Meishan Aostaral Aluminum with a capacity of 225,000 mt and Emei Qiya with a capacity of 150,000 mt, are both operating normally.

Transportation has been severely disrupted and smelters were unable to transport metals to other provinces in China. Central China’s mail railway from Baoji to Chengdu remains inoperable. Coal is transported on this railway from Shanxi and Shaanxi to northeast Sichuan Province.

That supply line has been interrupted. Sichuan also provides about 40% of China’s natural gas. China’s already stressed power distribution system could fall victim to more outages.

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