[M]iners at Chinese ventures complain about safety, low pay and conflicts that have spiraled into a spate of shootings… [R]ioting workers at a coal mine in southern Zambia killed a…Chinese supervisor, running him over with a mining cart…a Collum executive blame the revolt on a misunderstanding as to when a minimum-wage increase would take effect…At the same mine, in 2010, Chinese managers shot at least 13 striking coal miners…Early on, miners lacked boots, goggles and ear protection, according to Brighton Kateka…at the Mines Safety Department…He says safety at the Chinese-owned mines has since improved…In 2005, an explosion at a company associated with China Nonferrous killed more than 40 workers, said Mr. Kateka, one of the industry's most deadly accidents…[L]ast year, the Chambishi unit of China Nonferrous Metals was forced to rehire 1,000 miners it had fired to during a wage strike…Some Zambian union leaders say language gaps and culture clashes are as much to blame for labor frictions as wage differences…