Kazakhstan's government-run news agency has reported that the head of the state uranium producer, the world's largest, has died of a heart attack while on a visit to China. Kazinform news agency said Kazatomprom chairman Nurlan Kapparov, 44, collapsed early yesterday afternoon while having lunch at a restaurant in Beijing. Kapparov had been at the helm of Kazatomprom, the world's biggest uranium producer by output, since August. The company said this month that it produced 22,800 tons of uranium in 2014, equivalent to 40 percent of global output.