KO-CHIU

Pinyin Gejiu, city in southern Yunnan sheng (province), China. Ko-chiu lies near the Vietnamese border and is the site of China's most important tin-mining industry. Ko-chiu was originally a small mining settlement called Ko-chiu-chieh; mining of silver was begun there under the Yan (Mongol; 12061368) and Ming (13681644) dynasties. Mining in Yunnan boomed in the late 17th and 18th centuries, but tin mining in Ko-chiu did not develop until the second half of the 18th century. In the 1880s the city was created a sub-prefecture under Meng-tzu County, about 19 miles (30 km) to the east. In 1889 Meng-tzu was opened as a treaty port, its trade being almost entirely with Hanoi and Haiphong in Indochina. One of the main purposes in constructing the French-built railway from Haiphong to K'un-ming (Yunnan), completed in 1910, was to service the mines. A branch line was built from Ko-chiu to Meng-tzu between 1915 and 1928. During the last years of the Ch'ing dynasty (16441911/12), the mines were organized by the Chinese Ko-chiu Tin Company, but the company was deficient in capital, technical skill, and managerial efficiency and was replaced by a joint stateprivate company, the Ko-chiu Tin-Mining Company, under which production boomed. By the 1930s, Ko-chiu tin accounted for 80 percent of the traffic exported on the railway. In 1938 tin production is said to have reached 10,000 tons. Under the Communist government, management passed to the state Yunnan Tin-Mining Corporation, which by 1955 had reached and surpassed prewar production figures. In addition to tin, which remains the chief product, Ko-chiu has also become a major producer of lead. Coal for smelting is supplied to the city from K'ai-yan to the north, located on the rail line to K'un-ming. There is some engineering and chemical production closely allied with Ko-chiu's metallurgical industries. Pop. (1985 est.) city proper, 189,900; city, 337,700.